A Simplified, Low-Cost Method for Polarized Light Microscopy

PubMed Central

Maude, Richard J.; Buapetch, Wanchana; Silamut, Kamolrat

2009-01-01

Malaria pigment is an intracellular inclusion body that appears in blood and tissue specimens on microscopic examination and can help in establishing the diagnosis of malaria. In simple light microscopy, it can be difficult to discern from cellular background and artifacts. It has long been known that if polarized light microscopy is used, malaria pigment can be much easier to distinguish. However, this technique is rarely used because of the need for a relatively costly polarization microscope. We describe a simple and economical technique to convert any standard light microscope suitable for examination of malaria films into a polarization microscope. PMID:19861611

Adding an Extra Dimension to What Students See through the Light Microscope: A Lab Exercise Demonstrating Critical Analysis for Microscopy Students

ERIC Educational Resources Information Center

Garrill, Ashley

2011-01-01

This article describes an undergraduate lab exercise that demonstrates the importance of students thinking critically about what they see through a microscope. The students are given growth data from tip-growing organisms that suggest the cells grow in a pulsatile manner. The students then critique this data in several exercises that incorporate…

High-Bandwidth Dynamic Full-Field Profilometry for Nano-Scale Characterization of MEMS

NASA Astrophysics Data System (ADS)

Chen, Liang-Chia; Huang, Yao-Ting; Chang, Pi-Bai

2006-10-01

The article describes an innovative optical interferometric methodology to delivery dynamic surface profilometry with a measurement bandwidth up to 10MHz or higher and a vertical resolution up to 1 nm. Previous work using stroboscopic microscopic interferometry for dynamic characterization of micro (opto)electromechanical systems (M(O)EMS) has been limited in measurement bandwidth mainly within a couple of MHz. For high resonant mode analysis, the stroboscopic light pulse is insufficiently short to capture the moving fringes from dynamic motion of the detected structure. In view of this need, a microscopic prototype based on white-light stroboscopic interferometry with an innovative light superposition strategy was developed to achieve dynamic full-field profilometry with a high measurement bandwidth up to 10MHz or higher. The system primarily consists of an optical microscope, on which a Mirau interferometric objective embedded with a piezoelectric vertical translator, a high-power LED light module with dual operation modes and light synchronizing electronics unit are integrated. A micro cantilever beam used in AFM was measured to verify the system capability in accurate characterisation of dynamic behaviours of the device. The full-field seventh-mode vibration at a vibratory frequency of 3.7MHz can be fully characterized and nano-scale vertical measurement resolution as well as tens micrometers of vertical measurement range can be performed.

Effects of Er:YAG laser irradiation on human dentin: polarizing microscopic, light microscopic and microradiographic observations, and FT-IR analysis.

PubMed

Ishizaka, Yaeko; Eguro, Toru; Maeda, Toru; Tanaka, Hisayoshi

2002-01-01

The effects of Er:YAG laser irradiation on dentin have not been sufficiently investigated. The purpose of this study was to investigate the effects of Er:YAG laser irradiation on dentin. After cavities were prepared using Er:YAG laser irradiation or rotary cutting instruments, histological observations of cavity-floor dentin utilizing polarizing microscopy, microradiography and light microscopy, and analysis of composition of cavity-floor dentin using Fourier-transformed (FT-IR) spectrometry were conducted. In the laser-treated side, a deeply stained basophilic layer was observed. The number of odontoblastic processes present was obviously less in the laser-treated side than in the bur-treated side. FT-IR analysis revealed that compared to the bur-treated side, a broad background peak at around 1,600 cm(-1) was present. Er:YAG laser irradiation might have denatured the organic materials of dentin. Copyright 2002 Wiley-Liss, Inc.

3D geometric phase analysis and its application in 3D microscopic morphology measurement

NASA Astrophysics Data System (ADS)

Zhu, Ronghua; Shi, Wenxiong; Cao, Quankun; Liu, Zhanwei; Guo, Baoqiao; Xie, Huimin

2018-04-01

Although three-dimensional (3D) morphology measurement has been widely applied on the macro-scale, there is still a lack of 3D measurement technology on the microscopic scale. In this paper, a microscopic 3D measurement technique based on the 3D-geometric phase analysis (GPA) method is proposed. In this method, with machine vision and phase matching, the traditional GPA method is extended to three dimensions. Using this method, 3D deformation measurement on the micro-scale can be realized using a light microscope. Simulation experiments were conducted in this study, and the results demonstrate that the proposed method has a good anti-noise ability. In addition, the 3D morphology of the necking zone in a tensile specimen was measured, and the results demonstrate that this method is feasible.

Spectral analysis of scattered light from flowers' petals

NASA Astrophysics Data System (ADS)

Ozawa, Atsumi; Uehara, Tomomi; Sekiguchi, Fumihiko; Imai, Hajime

2009-07-01

A new method was developed for studying absorption characteristics of opaque samples based on the light scattering spectroscopy. Measurements were made in white, red and violet petals of Petunia hybrida, and gave the absorption spectra in a non-destructive manner without damaging the cell structures of the petal. The red petal has absorption peak at 550 nm and the violet has three absorption peaks: at 450, 670, and 550 nm. The results were discussed in correlation with the microscopic cell structures of the petal observed with optical microscope and transmission electron microscopy (TEM). Only the cells placed in the surface have the pigments giving the color of the petal.

Enhancing the performance of the light field microscope using wavefront coding.

PubMed

Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

2014-10-06

Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective's back focal plane and at the microscope's native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain.

Microcircuit failure analysis using the SEM. [Scanning Electron Microscopes

NASA Technical Reports Server (NTRS)

Nicolas, D. P.

1974-01-01

The scanning electron microscope adds a new dimension to the knowledge that can be obtained from a failed microcircuit. When used with conventional techniques, SEM assists and clarifies the analysis, but it does not replace light microscopy. The most advantageous features for microcircuit analysis are long working distances and great depth of field. Manufacturer related failure modes of microcircuits are metallization defects, poor bonding, surface and particle contamination, and design and fabrication faults. User related failure modes are caused by abuse, such as overstress. The Physics of Failure Procedure followed by the Astrionics Laboratory in failure analysis is described, which is designed to obtain maximum information available from each step.

Standoff detection of explosives: a challenging approach for optical technologies

NASA Astrophysics Data System (ADS)

Désilets, S.; Hô, N.; Mathieu, P.; Simard, J. R.; Puckrin, E.; Thériault, J. M.; Lavoie, H.; Théberge, F.; Babin, F.; Gay, D.; Forest, R.; Maheux, J.; Roy, G.; Châteauneuf, M.

2011-06-01

Standoff detection of explosives residues on surfaces at few meters was made using optical technologies based on Raman scattering, Laser-Induced Breakdown Spectroscopy (LIBS) and passive standoff FTIR radiometry. By comparison, detection and analysis of nanogram samples of different explosives was made with a microscope system where Raman scattering from a micron-size single point illuminated crystal of explosive was observed. Results from standoff detection experiments using a telescope were compared to experiments using a microscope to find out important parameters leading to the detection. While detection and spectral identification of the micron-size explosive particles was possible with a microscope, standoff detection of these particles was very challenging due to undesired light reflected and produced by the background surface or light coming from other contaminants. Results illustrated the challenging approach of detecting at a standoff distance the presence of low amount of micron or submicron explosive particles.

An integrated single- and two-photon non-diffracting light-sheet microscope

NASA Astrophysics Data System (ADS)

Lau, Sze Cheung; Chiu, Hoi Chun; Zhao, Luwei; Zhao, Teng; Loy, M. M. T.; Du, Shengwang

2018-04-01

We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution. When the light scattering becomes significant for a deep-cell or deep-tissue imaging, we use SBB light-sheet two-photon excitation with a longer wavelength. We achieved nearly identical lateral/axial resolution of about 350/270 nm for both imagings. This integrated light-sheet microscope may have a wide application for live-cell and live-tissue three-dimensional high-speed imaging.

Development of Low-Cost Inverted Microscope to Detect Early Growth of Mycobacterium tuberculosis in MODS Culture

PubMed Central

Zimic, Mirko; Velazco, Abner; Comina, Germán; Coronel, Jorge; Fuentes, Patricia; Luna, Carmen G.; Sheen, Patricia; Gilman, Robert H.; Moore, David A. J.

2010-01-01

Background The microscopic observation drug susceptibility (MODS) assay for rapid, low-cost detection of tuberculosis and multidrug resistant tuberculosis depends upon visualization of the characteristic cording colonies of Mycobacterium tuberculosis in liquid media. This has conventionally required an inverted light microscope in order to inspect the MODS culture plates from below. Few tuberculosis laboratories have this item and the capital cost of $5,000 for a high-end microscope could be a significant obstacle to MODS roll-out. Methodology We hypothesized that the precise definition provided by costly high-specification inverted light microscopes might not be necessary for pattern recognition. Significance In this work we describe the development of a low-cost artesenal inverted microscope that can operate in both a standard or digital mode to effectively replace the expensive commercial inverted light microscope, and an integrated system that could permit a local and remote diagnosis of tuberculosis. PMID:20351778

Macular photostress and visual experience between microscope and intracameral illumination during cataract surgery.

PubMed

Seo, Hyejin; Nam, Dong Heun; Lee, Jong Yeon; Park, Su Jin; Kim, Yu Jeong; Kim, Seong-Woo; Chung, Tae-Young; Inoue, Makoto; Kim, Terry

2018-02-01

To evaluate macular photostress and visual experience between coaxial microscope illumination versus oblique intracameral illumination during cataract surgery. Gachon University Gil Hospital, Incheon, South Korea. Prospective case series. Consecutive patients who had cataract surgery using microscope illumination and intracameral illumination were included. The patients were asked to complete a questionnaire (seeing strong lights, feeling photophobia, feeling startled (fright) when seeing lights, seeing any colors, seeing any instruments or surgical procedures, and estimating intraoperative visual function) designed to describe their cataract surgery experience. The images projected on the retina of the model eye (rear view) with artificial opaque fragments in the anterior chamber during simulating cataract surgery were compared between the 2 illumination types. Sixty patients completed the questionnaire. Scores for strong lights, photophobia, fright, and color perception were significantly higher with microscope illumination than with intracameral illumination (all P < .001). More patients preferred the intracameral illumination (45 [75.0%]) to the microscope illumination (13 [21.7%]). In the rear-view images created in a model eye, only the bright microscope light in the center was seen without any lens image in the microscope illumination. However, in the intracameral illumination, the less bright light from the light pipe in the periphery and the lens fragments were seen more clearly. In a view of the patients' visual experience, oblique intracameral illumination caused less subjective photostress and was preferred over coaxial microscope illumination. Objective findings from the model-eye experiment correlated to the result of visual experience. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

A comparative analysis of microscopic alterations in modern and ancient undecalcified and decalcified dry bones.

PubMed

Caruso, Valentina; Cummaudo, Marco; Maderna, Emanuela; Cappella, Annalisa; Caudullo, Giorgio; Scarpulla, Valentina; Cattaneo, Cristina

2018-02-01

The present study aims to evaluate the preservation of the microstructure of skeletal remains collected from four different known burial sites (archaeological and contemporary). Histological analysis on undecalcified and decalcified thin sections was performed in order to assess which of the two techniques is more affected by taphonomic insults. A histological analysis was performed on both undecalcified and decalcified thin sections of 40 long bones and the degree of diagenetic change was evaluated using transmitted and polarized light microscopy according to the Oxford Histological Index (OHI). In order to test the optical behavior of bone tissue, thin sections were observed by polarized light microscopy and the intensity of birefringence was evaluated. The more ancient samples are generally characterized by a low OHI (0-1) with extensive microscopic focal destruction; recent samples exhibited a better preservation of bone micromorphology. When comparing undecalcified to decalcified thin sections, the latter showed an amelioration in the conservation of microscopic structure. As regards the birefringence, it was very low in all the undecalcified thin sections, whereas decalcification process seems to improve its visibility. The preservation of the bone microscopic structure appears to be influenced not only by age, but also by the burial context. Undecalcified bones appear to be more affected by taphonomical alterations, probably because of the thickness of the thin sections; on the contrary, decalcified thin sections proved to be able to tackle this issue allowing a better reading of the bone tissue. © 2017 Wiley Periodicals, Inc.

Method for nanoscale spatial registration of scanning probes with substrates and surfaces

NASA Technical Reports Server (NTRS)

Wade, Lawrence A. (Inventor)

2010-01-01

Embodiments in accordance with the present invention relate to methods and apparatuses for aligning a scanning probe used to pattern a substrate, by comparing the position of the probe to a reference location or spot on the substrate. A first light beam is focused on a surface of the substrate as a spatial reference point. A second light beam then illuminates the scanning probe being used for patterning. An optical microscope images both the focused light beam, and a diffraction pattern, shadow, or light backscattered by the illuminated scanning probe tip of a scanning probe microscope (SPM), which is typically the tip of the scanning probe on an atomic force microscope (AFM). Alignment of the scanning probe tip relative to the mark is then determined by visual observation of the microscope image. This alignment process may be repeated to allow for modification or changing of the scanning probe microscope tip.

Light microscopic image analysis system to quantify immunoreactive terminal area apposed to nerve cells.

PubMed

Wu, L C; D'Amelio, F; Fox, R A; Polyakov, I; Daunton, N G

1997-06-06

The present report describes a desktop computer-based method for the quantitative assessment of the area occupied by immunoreactive terminals in close apposition to nerve cells in relation to the perimeter of the cell soma. This method is based on Fast Fourier Transform (FFT) routines incorporated in NIH-Image public domain software. Pyramidal cells of layer V of the somatosensory cortex outlined by GABA immunolabeled terminals were chosen for our analysis. A Leitz Diaplan light microscope was employed for the visualization of the sections. A Sierra Scientific Model 4030 CCD camera was used to capture the images into a Macintosh Centris 650 computer. After preprocessing, filtering was performed on the power spectrum in the frequency domain produced by the FFT operation. An inverse FFT with filter procedure was employed to restore the images to the spatial domain. Pasting of the original image to the transformed one using a Boolean logic operation called 'AND'ing produced an image with the terminals enhanced. This procedure allowed the creation of a binary image using a well-defined threshold of 128. Thus, the terminal area appears in black against a white background. This methodology provides an objective means of measurement of area by counting the total number of pixels occupied by immunoreactive terminals in light microscopic sections in which the difficulties of labeling intensity, size, shape and numerical density of terminals are avoided.

Light microscopic image analysis system to quantify immunoreactive terminal area apposed to nerve cells

NASA Technical Reports Server (NTRS)

Wu, L. C.; D'Amelio, F.; Fox, R. A.; Polyakov, I.; Daunton, N. G.

1997-01-01

The present report describes a desktop computer-based method for the quantitative assessment of the area occupied by immunoreactive terminals in close apposition to nerve cells in relation to the perimeter of the cell soma. This method is based on Fast Fourier Transform (FFT) routines incorporated in NIH-Image public domain software. Pyramidal cells of layer V of the somatosensory cortex outlined by GABA immunolabeled terminals were chosen for our analysis. A Leitz Diaplan light microscope was employed for the visualization of the sections. A Sierra Scientific Model 4030 CCD camera was used to capture the images into a Macintosh Centris 650 computer. After preprocessing, filtering was performed on the power spectrum in the frequency domain produced by the FFT operation. An inverse FFT with filter procedure was employed to restore the images to the spatial domain. Pasting of the original image to the transformed one using a Boolean logic operation called 'AND'ing produced an image with the terminals enhanced. This procedure allowed the creation of a binary image using a well-defined threshold of 128. Thus, the terminal area appears in black against a white background. This methodology provides an objective means of measurement of area by counting the total number of pixels occupied by immunoreactive terminals in light microscopic sections in which the difficulties of labeling intensity, size, shape and numerical density of terminals are avoided.

A light field microscope imaging spectrometer based on the microlens array

NASA Astrophysics Data System (ADS)

Yao, Yu-jia; Xu, Feng; Xia, Yin-xiang

2017-10-01

A new light field spectrometry microscope imaging system, which was composed by microscope objective, microlens array and spectrometry system was designed in this paper. 5-D information (4-D light field and 1-D spectrometer) of the sample could be captured by the snapshot system in only one exposure, avoiding the motion blur and aberration caused by the scanning imaging process of the traditional imaging spectrometry. Microscope objective had been used as the former group while microlens array used as the posterior group. The optical design of the system was simulated by Zemax, the parameter matching condition between microscope objective and microlens array was discussed significantly during the simulation process. The result simulated in the image plane was analyzed and discussed.

Intraoperative Fluorescence Cerebral Angiography by Laser Surgical Microscopy: Comparison With Xenon Microscopy and Simultaneous Observation of Cerebral Blood Flow and Surrounding Structures.

PubMed

Ito, Yuhei; Suzuki, Kyouichi; Ichikawa, Tsuyoshi; Watanabe, Yoichi; Sato, Taku; Sakuma, Jun; Saito, Kiyoshi

2018-06-12

Laser surgical microscopes should enable uniform illumination of the operative field, and require less luminous energy compared with existing xenon surgical microscopes. To examine the utility of laser illumination in fluorescence cerebral angiography. Fluorescein sodium (fluorescein) was used as a fluorescent dye. We first compared the clarity of cerebral blood flow images collected by fluorescence angiography between the laser illumination and xenon illumination methods. We then assessed use of the laser illuminator for simultaneous observation of blood flow and surrounding structures during fluorescence angiography. Furthermore, the study was designed to evaluate usefulness of the thus determined excitation light in clinical cases. Fluorescence angiography using blue light laser for excitation provided higher clarity and contrast blood flow images compared with using blue light generated from a xenon lamp. Further, illumination with excitation light consisting of a combination of 3 types of laser (higher level of blue light, no green light, and lower level of red light) enabled both blood flow and surrounding structures to be observed through the microscope directly by the surgeon. Laser-illuminated fluorescence angiography provides high clarity and contrast images of cerebral blood flow. Further, a laser providing strong blue light and weak red light for excitation light enables simultaneous visual observation of fluorescent blood flow and surrounding structures by the surgeon using a surgical microscope. Overall, these data suggest that laser surgical microscopes are useful for both ordinary operative manipulations and fluorescence angiography.

Comprehensive optical and data management infrastructure for high-throughput light-sheet microscopy of whole mouse brains.

PubMed

Müllenbroich, M Caroline; Silvestri, Ludovico; Onofri, Leonardo; Costantini, Irene; Hoff, Marcel Van't; Sacconi, Leonardo; Iannello, Giulio; Pavone, Francesco S

2015-10-01

Comprehensive mapping and quantification of neuronal projections in the central nervous system requires high-throughput imaging of large volumes with microscopic resolution. To this end, we have developed a confocal light-sheet microscope that has been optimized for three-dimensional (3-D) imaging of structurally intact clarified whole-mount mouse brains. We describe the optical and electromechanical arrangement of the microscope and give details on the organization of the microscope management software. The software orchestrates all components of the microscope, coordinates critical timing and synchronization, and has been written in a versatile and modular structure using the LabVIEW language. It can easily be adapted and integrated to other microscope systems and has been made freely available to the light-sheet community. The tremendous amount of data routinely generated by light-sheet microscopy further requires novel strategies for data handling and storage. To complete the full imaging pipeline of our high-throughput microscope, we further elaborate on big data management from streaming of raw images up to stitching of 3-D datasets. The mesoscale neuroanatomy imaged at micron-scale resolution in those datasets allows characterization and quantification of neuronal projections in unsectioned mouse brains.

Microscopic theory of linear light scattering from mesoscopic media and in near-field optics.

PubMed

Keller, Ole

2005-08-01

On the basis of quantum mechanical response theory a microscopic propagator theory of linear light scattering from mesoscopic systems is presented. The central integral equation problem is transferred to a matrix equation problem by discretization in transitions between pairs of (many-body) energy eigenstates. The local-field calculation which appears from this approach is valid down to the microscopic region. Previous theories based on the (macroscopic) dielectric constant concept make use of spatial (geometrical) discretization and cannot in general be trusted on the mesoscopic length scale. The present theory can be applied to light scattering studies in near-field optics. After a brief discussion of the macroscopic integral equation problem a microscopic potential description of the scattering process is established. In combination with the use of microscopic electromagnetic propagators the formalism allows one to make contact to the macroscopic theory of light scattering and to the spatial photon localization problem. The quantum structure of the microscopic conductivity response tensor enables one to establish a clear physical picture of the origin of local-field phenomena in mesoscopic and near-field optics. The Huygens scalar propagator formalism is revisited and its generality in microscopic physics pointed out.

Enhancing the performance of the light field microscope using wavefront coding

PubMed Central

Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

2014-01-01

Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective’s back focal plane and at the microscope’s native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain. PMID:25322056

Microscopic vision modeling method by direct mapping analysis for micro-gripping system with stereo light microscope.

PubMed

Wang, Yuezong; Zhao, Zhizhong; Wang, Junshuai

2016-04-01

We present a novel and high-precision microscopic vision modeling method, which can be used for 3D data reconstruction in micro-gripping system with stereo light microscope. This method consists of four parts: image distortion correction, disparity distortion correction, initial vision model and residual compensation model. First, the method of image distortion correction is proposed. Image data required by image distortion correction comes from stereo images of calibration sample. The geometric features of image distortions can be predicted though the shape deformation of lines constructed by grid points in stereo images. Linear and polynomial fitting methods are applied to correct image distortions. Second, shape deformation features of disparity distribution are discussed. The method of disparity distortion correction is proposed. Polynomial fitting method is applied to correct disparity distortion. Third, a microscopic vision model is derived, which consists of two models, i.e., initial vision model and residual compensation model. We derive initial vision model by the analysis of direct mapping relationship between object and image points. Residual compensation model is derived based on the residual analysis of initial vision model. The results show that with maximum reconstruction distance of 4.1mm in X direction, 2.9mm in Y direction and 2.25mm in Z direction, our model achieves a precision of 0.01mm in X and Y directions and 0.015mm in Z direction. Comparison of our model with traditional pinhole camera model shows that two kinds of models have a similar reconstruction precision of X coordinates. However, traditional pinhole camera model has a lower precision of Y and Z coordinates than our model. The method proposed in this paper is very helpful for the micro-gripping system based on SLM microscopic vision. Copyright © 2016 Elsevier Ltd. All rights reserved.

An improved light microscopical histoquantitative method for the stereological analysis of the rat ventral prostate lobe.

PubMed

Romppanen, T; Huttunen, E; Helminen, H J

1980-07-01

An improved light microscopical histoquantitative method for the analysis of the stereologic structure of the ventral lobe of the rat prostate is introduced. From paraffin-embedded tissue sections, volumetric fractions of the acinar parenchyma, the glandular epithelium, the glandular lumen, and the interacinar tissue were determined. The surface density of the glandular epithelium and the length density of the glandular tubules per cubic millimeter of tissue were also calculated. The corresponding total amount/quantity of each tissue compartment was computed for the whole ventral lobe based on the weight of the lobe. Using established stereologic laws, the height of the epithelium, the diameter of the glandular tubules, the free distance between the glandular tubules, and the distance between the glandular centers (means) were determined. The fitness of the method was tested by analyzing, in addition to normal prostates, ventral prostates of rats castrated 30 days before sacrifice.

Integrated light and scanning electron microscopy of GFP-expressing cells.

PubMed

Peddie, Christopher J; Liv, Nalan; Hoogenboom, Jacob P; Collinson, Lucy M

2014-01-01

Integration of light and electron microscopes provides imaging tools in which fluorescent proteins can be localized to cellular structures with a high level of precision. However, until recently, there were few methods that could deliver specimens with sufficient fluorescent signal and electron contrast for dual imaging without intermediate staining steps. Here, we report protocols that preserve green fluorescent protein (GFP) in whole cells and in ultrathin sections of resin-embedded cells, with membrane contrast for integrated imaging. Critically, GFP is maintained in a stable and active state within the vacuum of an integrated light and scanning electron microscope. For light microscopists, additional structural information gives context to fluorescent protein expression in whole cells, illustrated here by analysis of filopodia and focal adhesions in Madin Darby canine kidney cells expressing GFP-Paxillin. For electron microscopists, GFP highlights the proteins of interest within the architectural space of the cell, illustrated here by localization of the conical lipid diacylglycerol to cellular membranes. © 2014 Elsevier Inc. All rights reserved.

Setting Up a Simple Light Sheet Microscope for In Toto Imaging of C. elegans Development

PubMed Central

Bertrand, Vincent; Lenne, Pierre-François

2014-01-01

Fast and low phototoxic imaging techniques are pre-requisite to study the development of organisms in toto. Light sheet based microscopy reduces photo-bleaching and phototoxic effects compared to confocal microscopy, while providing 3D images with subcellular resolution. Here we present the setup of a light sheet based microscope, which is composed of an upright microscope and a small set of opto-mechanical elements for the generation of the light sheet. The protocol describes how to build, align the microscope and characterize the light sheet. In addition, it details how to implement the method for in toto imaging of C. elegans embryos using a simple observation chamber. The method allows the capture of 3D two-colors time-lapse movies over few hours of development. This should ease the tracking of cell shape, cell divisions and tagged proteins over long periods of time. PMID:24836407

Elemental distribution analysis of urinary crystals.

PubMed

Fazil Marickar, Y M; Lekshmi, P R; Varma, Luxmi; Koshy, Peter

2009-10-01

Various crystals are seen in human urine. Some of them, particularly calcium oxalate dihydrate, are seen normally. Pathological crystals indicate crystal formation initiating urinary stones. Unfortunately, many of the relevant crystals are not recognized in light microscopic analysis of the urinary deposit performed in most of the clinical laboratories. Many crystals are not clearly identifiable under the ordinary light microscopy. The objective of the present study was to perform scanning electron microscopic (SEM) assessment of various urinary deposits and confirm the identity by elemental distribution analysis (EDAX). 50 samples of urinary deposits were collected from urinary stone clinic. Deposits containing significant crystalluria (more than 10 per HPF) were collected under liquid paraffin in special containers and taken up for SEM studies. The deposited crystals were retrieved with appropriate Pasteur pipettes, and placed on micropore filter paper discs. The fluid was absorbed by thicker layers of filter paper underneath and discs were fixed to brass studs. They were then gold sputtered to 100 A and examined under SEM (Jeol JSM 35C microscope). When crystals were seen, their morphology was recorded by taking photographs at different angles. At appropriate magnification, EDAX probe was pointed to the crystals under study and the wave patterns analyzed. Components of the crystals were recognized by utilizing the data. All the samples analyzed contained significant number of crystals. All samples contained more than one type of crystal. The commonest crystals encountered included calcium oxalate monohydrate (whewellite 22%), calcium oxalate dihydrate (weddellite 32%), uric acid (10%), calcium phosphates, namely, apatite (4%), brushite (6%), struvite (6%) and octocalcium phosphate (2%). The morphological appearances of urinary crystals described were correlated with the wavelengths obtained through elemental distribution analysis. Various urinary crystals that are not reported under light microscopy could be recognized by SEM-EDAX combination. EDAX is a significant tool for recognizing unknown crystals not identified by ordinary light microscopy or SEM alone.

Surface plasmon resonance microscopy: achieving a quantitative optical response

PubMed Central

Peterson, Alexander W.; Halter, Michael; Plant, Anne L.; Elliott, John T.

2016-01-01

Surface plasmon resonance (SPR) imaging allows real-time label-free imaging based on index of refraction, and changes in index of refraction at an interface. Optical parameter analysis is achieved by application of the Fresnel model to SPR data typically taken by an instrument in a prism based configuration. We carry out SPR imaging on a microscope by launching light into a sample, and collecting reflected light through a high numerical aperture microscope objective. The SPR microscope enables spatial resolution that approaches the diffraction limit, and has a dynamic range that allows detection of subnanometer to submicrometer changes in thickness of biological material at a surface. However, unambiguous quantitative interpretation of SPR changes using the microscope system could not be achieved using the Fresnel model because of polarization dependent attenuation and optical aberration that occurs in the high numerical aperture objective. To overcome this problem, we demonstrate a model to correct for polarization diattenuation and optical aberrations in the SPR data, and develop a procedure to calibrate reflectivity to index of refraction values. The calibration and correction strategy for quantitative analysis was validated by comparing the known indices of refraction of bulk materials with corrected SPR data interpreted with the Fresnel model. Subsequently, we applied our SPR microscopy method to evaluate the index of refraction for a series of polymer microspheres in aqueous media and validated the quality of the measurement with quantitative phase microscopy. PMID:27782542

Application of principal component analysis to multispectral-multimodal optical image analysis for malaria diagnostics.

PubMed

Omucheni, Dickson L; Kaduki, Kenneth A; Bulimo, Wallace D; Angeyo, Hudson K

2014-12-11

Multispectral imaging microscopy is a novel microscopic technique that integrates spectroscopy with optical imaging to record both spectral and spatial information of a specimen. This enables acquisition of a large and more informative dataset than is achievable in conventional optical microscopy. However, such data are characterized by high signal correlation and are difficult to interpret using univariate data analysis techniques. In this work, the development and application of a novel method which uses principal component analysis (PCA) in the processing of spectral images obtained from a simple multispectral-multimodal imaging microscope to detect Plasmodium parasites in unstained thin blood smear for malaria diagnostics is reported. The optical microscope used in this work has been modified by replacing the broadband light source (tungsten halogen lamp) with a set of light emitting diodes (LEDs) emitting thirteen different wavelengths of monochromatic light in the UV-vis-NIR range. The LEDs are activated sequentially to illuminate same spot of the unstained thin blood smears on glass slides, and grey level images are recorded at each wavelength. PCA was used to perform data dimensionality reduction and to enhance score images for visualization as well as for feature extraction through clusters in score space. Using this approach, haemozoin was uniquely distinguished from haemoglobin in unstained thin blood smears on glass slides and the 590-700 spectral range identified as an important band for optical imaging of haemozoin as a biomarker for malaria diagnosis. This work is of great significance in reducing the time spent on staining malaria specimens and thus drastically reducing diagnosis time duration. The approach has the potential of replacing a trained human eye with a trained computerized vision system for malaria parasite blood screening.

AccessScope project: Accessible light microscope for users with upper limb mobility or visual impairments.

PubMed

Mansoor, Awais; Ahmed, Wamiq M; Samarapungavan, Ala; Cirillo, John; Schwarte, David; Robinson, J Paul; Duerstock, Bradley S

2010-01-01

A web-based application was developed to remotely view slide specimens and control all functions of a research-level light microscopy workstation, called AccessScope. Students and scientists with upper limb mobility and visual impairments are often unable to use a light microscope by themselves and must depend on others in its operation. Users with upper limb mobility impairments and low vision were recruited to assist in the design process of the AccessScope personal computer (PC) user interface. Participants with these disabilities were evaluated in their ability to use AccessScope to perform microscopical tasks. AccessScope usage was compared with inspecting prescanned slide images by grading participants' identification and understanding of histological features and knowledge of microscope operation. With AccessScope subjects were able to independently perform common light microscopy functions through an Internet browser by employing different PC pointing devices or accessibility software according to individual abilities. Subjects answered more histology and microscope usage questions correctly after first participating in an AccessScope test session. AccessScope allowed users with upper limb or visual impairments to successfully perform light microscopy without assistance. This unprecedented capability is crucial for students and scientists with disabilities to perform laboratory coursework or microscope-based research and pursue science, technology, engineering, and mathematics fields.

Introduction to Modern Methods in Light Microscopy.

PubMed

Ryan, Joel; Gerhold, Abby R; Boudreau, Vincent; Smith, Lydia; Maddox, Paul S

2017-01-01

For centuries, light microscopy has been a key method in biological research, from the early work of Robert Hooke describing biological organisms as cells, to the latest in live-cell and single-molecule systems. Here, we introduce some of the key concepts related to the development and implementation of modern microscopy techniques. We briefly discuss the basics of optics in the microscope, super-resolution imaging, quantitative image analysis, live-cell imaging, and provide an outlook on active research areas pertaining to light microscopy.

LC-lens array with light field algorithm for 3D biomedical applications

NASA Astrophysics Data System (ADS)

Huang, Yi-Pai; Hsieh, Po-Yuan; Hassanfiroozi, Amir; Martinez, Manuel; Javidi, Bahram; Chu, Chao-Yu; Hsuan, Yun; Chu, Wen-Chun

2016-03-01

In this paper, liquid crystal lens (LC-lens) array was utilized in 3D bio-medical applications including 3D endoscope and light field microscope. Comparing with conventional plastic lens array, which was usually placed in 3D endoscope or light field microscope system to record image disparity, our LC-lens array has higher flexibility of electrically changing its focal length. By using LC-lens array, the working distance and image quality of 3D endoscope and microscope could be enhanced. Furthermore, the 2D/3D switching ability could be achieved if we turn off/on the electrical power on LClens array. In 3D endoscope case, a hexagonal micro LC-lens array with 350um diameter was placed at the front end of a 1mm diameter endoscope. With applying electric field on LC-lens array, the 3D specimen would be recorded as from seven micro-cameras with different disparity. We could calculate 3D construction of specimen with those micro images. In the other hand, if we turn off the electric field on LC-lens array, the conventional high resolution 2D endoscope image would be recorded. In light field microscope case, the LC-lens array was placed in front of the CMOS sensor. The main purpose of LC-lens array is to extend the refocusing distance of light field microscope, which is usually very narrow in focused light field microscope system, by montaging many light field images sequentially focusing on different depth. With adjusting focal length of LC-lens array from 2.4mm to 2.9mm, the refocusing distance was extended from 1mm to 11.3mm. Moreover, we could use a LC wedge to electrically shift the optics axis and increase the resolution of light field.

Ultrastructure of cholinergic neurons in the laterodorsal tegmental nucleus of the rat: interaction with catecholamine fibers.

PubMed

Kubota, Y; Leung, E; Vincent, S R

1992-01-01

The ultrastructure of choline acetyltransferase (ChAT)-immunoreactive neurons in the laterodorsal tegmental nucleus (TLD) of the rat was investigated by immunohistochemical techniques. The immunoreactive neurons were medium to large in size, with a few elongated dendrites, contained well-developed cytoplasm, and a nucleus with deep infoldings. They received many nonimmunoreactive, mostly asymmetric synaptic inputs on their soma and dendrites. ChAT-immunoreactive, usually myelinated, axons were occasionally seen in TLD. Only one immunoreactive axon terminal was observed within TLD, and it made synaptic contact with a nonimmunoreactive neuronal perikaryon. The synaptic interactions between ChAT-immunoreactive neurons and tyrosine hydroxylase (TH)-immunoreactive fibers in the TLD were investigated with a double immunohistochemical staining method. ChAT-immunoreactivity detected with a beta-galactosidase method was light blue-green in the light microscope and formed dot-like electron dense particles at the electron microscopic level. TH-immunoreactivity, visualized with a nickel-enhanced immunoperoxidase method, was dark blue-black in the light microscope and diffusely opaque in the electron microscope. Therefore, the difference between these two kinds of immunoreactivity could be quite easily distinguished at both light and electron microscopic levels. In the light microscope, TH-positive fibers were often closely apposed to ChAT-immunoreactive cell bodies and dendrites in TLD. In the electron microscope, the cell soma and proximal dendrites of ChAT-immunoreactive neurons received synaptic contacts from TH-immunoreactive axon terminals. These results provide a morphological basis for catecholaminergic regulation of the cholinergic reticular system.

Confocal laser scanning microscopic photoconversion: a new method to stabilize fluorescently labeled cellular elements for electron microscopic analysis.

PubMed

Colello, Raymond J; Tozer, Jordan; Henderson, Scott C

2012-01-01

Photoconversion, the method by which a fluorescent dye is transformed into a stable, osmiophilic product that can be visualized by electron microscopy, is the most widely used method to enable the ultrastructural analysis of fluorescently labeled cellular structures. Nevertheless, the conventional method of photoconversion using widefield fluorescence microscopy requires long reaction times and results in low-resolution cell targeting. Accordingly, we have developed a photoconversion method that ameliorates these limitations by adapting confocal laser scanning microscopy to the procedure. We have found that this method greatly reduces photoconversion times, as compared to conventional wide field microscopy. Moreover, region-of-interest scanning capabilities of a confocal microscope facilitate the targeting of the photoconversion process to individual cellular or subcellular elements within a fluorescent field. This reduces the area of the cell exposed to light energy, thereby reducing the ultrastructural damage common to this process when widefield microscopes are employed. © 2012 by John Wiley & Sons, Inc.

Electron microscopic evaluation of a gold glaucoma micro shunt after explantation.

PubMed

Berk, Thomas A; Tam, Diamond Y; Werner, Liliana; Mamalis, Nick; Ahmed, Iqbal Ike K

2015-03-01

We present a case of an explanted gold glaucoma micro shunt (GMS Plus) and the subsequent light and electron microscopic analyses. The shunt was implanted in a patient with medically refractive glaucoma. The intraocular pressure (IOP) was stable at 12 mm Hg 6 months postoperatively but spiked to 26 mm Hg 6 months later; membranous growth was visible on the implant gonioscopically. A second gold micro shunt was placed 2 years after the first. The IOP was 7 mm Hg 1 week postoperatively but increased to 23 mm Hg 3 weeks later; similar membranous growth was visible on this implant. One of the shunts was explanted, and light and scanning electron microscopic analyses revealed encapsulation around the shunt exterior and connective tissue invasion of the microstructure. This represents the first electron microscopic analysis of an explanted gold glaucoma micro shunt and the first unequivocal images of the fibrotic pseudo-capsule traversing its microchannels and fenestrations. Dr. Ahmed is a consultant to and has received research grants from Solx, Inc. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Plasma cell quantification in bone marrow by computer-assisted image analysis.

PubMed

Went, P; Mayer, S; Oberholzer, M; Dirnhofer, S

2006-09-01

Minor and major criteria for the diagnosis of multiple meloma according to the definition of the WHO classification include different categories of the bone marrow plasma cell count: a shift from the 10-30% group to the > 30% group equals a shift from a minor to a major criterium, while the < 10% group does not contribute to the diagnosis. Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of this study was (i) to establish a digital image analysis system able to quantify bone marrow plasma cells and (ii) to evaluate two quantification techniques in bone marrow trephines i.e. computer-assisted digital image analysis and conventional light-microscopic evaluation. The results were compared regarding inter-observer variation of the obtained results. Eighty-seven patients, 28 with multiple myeloma, 29 with monoclonal gammopathy of undetermined significance, and 30 with reactive plasmocytosis were included in the study. Plasma cells in H&E- and CD138-stained slides were quantified by two investigators using light-microscopic estimation and computer-assisted digital analysis. The sets of results were correlated with rank correlation coefficients. Patients were categorized according to WHO criteria addressing the plasma cell content of the bone marrow (group 1: 0-10%, group 2: 11-30%, group 3: > 30%), and the results compared by kappa statistics. The degree of agreement in CD138-stained slides was higher for results obtained using the computer-assisted image analysis system compared to light microscopic evaluation (corr.coeff. = 0.782), as was seen in the intra- (corr.coeff. = 0.960) and inter-individual results correlations (corr.coeff. = 0.899). Inter-observer agreement for categorized results (SM/PW: kappa 0.833) was in a high range. Computer-assisted image analysis demonstrated a higher reproducibility of bone marrow plasma cell quantification. This might be of critical importance for diagnosis, clinical management and prognostics when plasma cell numbers are low, which makes exact quantifications difficult.

Microscopic observation of magnetic bacteria in the magnetic field of a rotating permanent magnet.

PubMed

Smid, Pieter; Shcherbakov, Valeriy; Petersen, Nikolai

2015-09-01

Magnetotactic bacteria are ubiquitous and can be found in both freshwater and marine environments. Due to intracellular chains of magnetic single domain particles, they behave like swimming compass needles. In external magnetic fields like the Earth's magnetic field, a torque is acting on the chain. This will cause the bacterium to be rotated and aligned with the external field. The swimming direction of magnetotactic bacteria can be controlled with external magnetic fields, which makes it convenient to study them under a light microscope. Usually, a special set of coils arranged around a light microscope is used to control the swimming magnetotactic bacteria. Here, we present a simple mechanical system with a permanent magnet, which produces a rotating magnetic field of nearly constant amplitude in the focal plane of a light microscope. The device is placed beside the light microscope and easily adaptable to almost any microscope and thus convenient for field experiments. To describe the trajectories qualitatively, a theoretical model of the trajectories is presented. This device can be used to control the swimming direction of magnetotactic bacteria and also for studying their magnetic and hydrodynamic properties.

Scanning Miniature Microscopes without Lenses

NASA Technical Reports Server (NTRS)

Wang, Yu

2009-01-01

The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the nonpolarizing beam splitter were replaced by a polarizing one, then the specimen would be illuminated by s-polarized light. Upon reflection from the specimen, some of the s-polarized light would become p-polarized. Only the p-polarized light would contribute to the image on the CCD; in other words, the image would contain information on the polarization rotating characteristic of the specimen.

A computer-assisted microscopic analysis of bone tissue developed inside a polyactive polymer implanted into an equine articular surface.

PubMed

Albert, Réka; Vásárhelyi, Gábor; Bodó, Gábor; Kenyeres, Annamária; Wolf, Ervin; Papp, Tamás; Terdik, Tünde; Módis, László; Felszeghy, Szabolcs

2012-09-01

One of the most promising applications for the restoration of small or moderately sized focal articular lesions is mosaicplasty (MP). Although recurrent hemarthrosis is a rare complication after MP, recently, various strategies have been designed to find an effective filling material to prevent postoperative bleeding from the donor site. The porous biodegradable polymer Polyactive (PA; a polyethylene glycol terephthalate - polybutylene terephthalate copolymer) represents a promising solution in this respect. A histological evaluation of the longterm PA-filled donor sites obtained from 10 experimental horses was performed. In this study, attention was primarily focused on the bone tissue developed in the plug. A computer-assisted image analysis and quantitative polarized light microscopic measurements of decalcified, longitudinally sectioned, dimethylmethylene blue (DMMB)- and picrosirius red (PS) stained sections revealed that the coverage area of the bone trabecules in the PA-filled donor tunnels was substantially (25%) enlarged compared to the neighboring cancellous bone. For this quantification, identical ROIs (regions of interest) were used and compared. The birefringence retardation values were also measured with a polarized light microscope using monochromatic light. Identical retardation values could be recorded from the bone trabeculae developed in the PA and in the neighboring bone, which indicates that the collagen orientation pattern does not differ significantly among these bone trabecules. Based on our new data, we speculate that PA promotes bone formation, and some of the currently identified degradation products of PA may enhance osteo-conduction and osteoinduction inside the donor canal.

Diffraction Pattern Analysis as an Optical Inspection Technique

DTIC Science & Technology

1991-08-01

BACKGROUND Diameters of fiber samples have commonly been measured manually with an optical microscope. Marcuse and Presby developed an automatic...by analyzing the back-scattered light when a beam of laser light impinged upon the fiber [2]. Presby and Marcuse extended this back-scattering tech...be im- proved further in order to become a feasible method for detecting a small number of blocked openings in CRT screens. 20 REFERENCES 1. Marcuse

Very low risk of light-induced retinal damage during Boston keratoprosthesis surgery: a rabbit study.

PubMed

Salvador-Culla, Borja; Behlau, Irmgard; Sayegh, Rony R; Stacy, Rebecca C; Dohlman, Claes H; Delori, François

2014-02-01

The aim of this study was to assess the possibility of light damage to the retina by a surgical microscope during implantation of a Boston Keratoprosthesis (B-KPro) in rabbits. The retinal irradiance from a Zeiss OPMI Lumera S7 operating microscope was measured at the working distance (16.5 cm). Light transmittance through an isolated B-KPro was measured. A B-KPro was implanted into 1 eye of 12 rabbits with the optic covered during the procedure. The operated eyes were then continuously exposed to a fixed light intensity under the microscope for 1 hour. Fluorescein angiography was carried out on days 2 and 9 postsurgery, after which the animals were euthanized. Further, we compared the potential of these retinal exposures to well-accepted light safety guidelines applicable to humans. Light transmittance of B-KPro revealed a blockage of short wavelengths (<390 nm) and of long wavelengths (1660-1750 nm) of light. In addition, the surgical microscope filtered a part of the blue, ultraviolet, and infrared wavelengths. Neither fluorescein angiography nor a histological examination showed any morphological retinal changes in our rabbits. Moreover, the retinal exposures were well below the safety limits. Modern surgical microscopes have filters incorporated in them that block the most damaging wavelengths of light. The B-KPro is made of 100% poly(methyl methacrylate), which makes it in itself a blocker of short wavelengths of light. No damage could be demonstrated in the animal study, and the retinal exposures were well below the safety limits. Together, these results suggest that light exposures during B-KPro surgery present a low risk of photochemical damage to the retina.

Biological applications of an LCoS-based programmable array microscope (PAM)

NASA Astrophysics Data System (ADS)

Hagen, Guy M.; Caarls, Wouter; Thomas, Martin; Hill, Andrew; Lidke, Keith A.; Rieger, Bernd; Fritsch, Cornelia; van Geest, Bert; Jovin, Thomas M.; Arndt-Jovin, Donna J.

2007-02-01

We report on a new generation, commercial prototype of a programmable array optical sectioning fluorescence microscope (PAM) for rapid, light efficient 3D imaging of living specimens. The stand-alone module, including light source(s) and detector(s), features an innovative optical design and a ferroelectric liquid-crystal-on-silicon (LCoS) spatial light modulator (SLM) instead of the DMD used in the original PAM design. The LCoS PAM (developed in collaboration with Cairn Research, Ltd.) can be attached to a port of a(ny) unmodified fluorescence microscope. The prototype system currently operated at the Max Planck Institute incorporates a 6-position high-intensity LED illuminator, modulated laser and lamp light sources, and an Andor iXon emCCD camera. The module is mounted on an Olympus IX71 inverted microscope with 60-150X objectives with a Prior Scientific x,y, and z high resolution scanning stages. Further enhancements recently include: (i) point- and line-wise spectral resolution and (ii) lifetime imaging (FLIM) in the frequency domain. Multiphoton operation and other nonlinear techniques should be feasible. The capabilities of the PAM are illustrated by several examples demonstrating single molecule as well as lifetime imaging in live cells, and the unique capability to perform photoconversion with arbitrary patterns and high spatial resolution. Using quantum dot coupled ligands we show real-time binding and subsequent trafficking of individual ligand-growth factor receptor complexes on and in live cells with a temporal resolution and sensitivity exceeding those of conventional CLSM systems. The combined use of a blue laser and parallel LED or visible laser sources permits photoactivation and rapid kinetic analysis of cellular processes probed by photoswitchable visible fluorescent proteins such as DRONPA.

Infrared microscope inspection apparatus

DOEpatents

Forman, S.E.; Caunt, J.W.

1985-02-26

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

Infrared microscope inspection apparatus

DOEpatents

Forman, Steven E.; Caunt, James W.

1985-02-26

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

Three-dimensional automated nanoparticle tracking using Mie scattering in an optical microscope.

PubMed

Gineste, J-M; Macko, P; Patterson, E A; Whelan, M P

2011-08-01

The forward scattering of light in a conventional inverted optical microscope by nanoparticles ranging in diameter from 10 to 50nm has been used to automatically and quantitatively identify and track their location in three-dimensions with a temporal resolution of 200ms. The standard deviation of the location of nominally stationary 50-nm-diameter nanoparticles was found to be about 50nm along the light path and about 5nm in the plane perpendicular to the light path. The method is based on oscillating the microscope objective along the light path using a piezo actuator and acquiring images with the condenser aperture closed to a minimum to enhance the effects of diffraction. Data processing in the time and spatial domains allowed the location of particles to be obtained automatically so that the technique has potential applications both in the processing of nanoparticles and in their use in a variety of fields including nanobiotechnology, pharmaceuticals and food processing where a simple optical microscope maybe preferred for a variety of reasons. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

Analysis of thick brain sections by obverse-reverse computer microscopy: application of a new, high clarity Golgi-Nissl stain.

PubMed

Glaser, E M; Van der Loos, H

1981-08-01

Exceptionally clear Golgi-Nissl sections of 300 micron thickness have been morphometrically studied by light microscopy using oil immersion objectives. The clarity results from a new variation of a staining procedure that combines Golgi and Nissl images in one section. A viewing technique has been developed that permits a histologic preparation to be examined from its obverse (or normally viewed) side and its reverse (or under) side. The technique was designed for use with a computer microscope but can be employed with any light microscope whose stage position can be measured within 100 micron. Sections thicker than 300 micron can be studied dependent on the working distance of the objective lens, provided that the clarity of the material permits it.

Volumetric bioimaging based on light field microscopy with temporal focusing illumination

NASA Astrophysics Data System (ADS)

Hsu, Feng-Chun; Sie, Yong Da; Lai, Feng-Jie; Chen, Shean-Jen

2018-02-01

Light field technique at a single shot can get the whole volume image of observed sample. Therefore, the original frame rate of the optical system can be taken as the volumetric image rate. For dynamically imaging whole micron-scale biosample, a light field microscope with temporal focusing illumination has been developed. In the light field microscope, the f-number of the microlens array (MLA) is adopted to match that of the objective; hence, the subimages via adjacent lenslets do not overlay each other. A three-dimensional (3D) deconvolution algorithm is utilized to deblur the out-of-focusing part. Conventional light field microscopy (LFM) illuminates whole volume sample even noninteresting parts; nevertheless, whole volume excitation causes even more damage on bio-sample and also increase the background noise from the out of range. Therefore, temporal focusing is integrated into the light field microscope for selecting the illumination volume. Herein, a slit on the back focal plane of the objective is utilized to control the axial excitation confinement for selecting the illumination volume. As a result, the developed light field microscope with the temporal focusing multiphoton illumination (TFMPI) can reconstruct 3D images within the selected volume, and the lateral resolution approaches to the theoretical value. Furthermore, the 3D Brownian motion of two-micron fluorescent beads is observed as the criterion of dynamic sample. With superior signal-to-noise ratio and less damage to tissue, the microscope is potential to provide volumetric imaging for vivo sample.

A hybrid scanning force and light microscope for surface imaging and three-dimensional optical sectioning in differential interference contrast.

PubMed

Stemmer, A

1995-04-01

The design of a scanned-cantilever-type force microscope is presented which is fully integrated into an inverted high-resolution video-enhanced light microscope. This set-up allows us to acquire thin optical sections in differential interference contrast (DIC) or polarization while the force microscope is in place. Such a hybrid microscope provides a unique platform to study how cell surface properties determine, or are affected by, the three-dimensional dynamic organization inside the living cell. The hybrid microscope presented in this paper has proven reliable and versatile for biological applications. It is the only instrument that can image a specimen by force microscopy and high-power DIC without having either to translate the specimen or to remove the force microscope. Adaptation of the design features could greatly enhance the suitability of other force microscopes for biological work.

Light Microscopy at Maximal Precision

NASA Astrophysics Data System (ADS)

Bierbaum, Matthew; Leahy, Brian D.; Alemi, Alexander A.; Cohen, Itai; Sethna, James P.

2017-10-01

Microscopy is the workhorse of the physical and life sciences, producing crisp images of everything from atoms to cells well beyond the capabilities of the human eye. However, the analysis of these images is frequently little more accurate than manual marking. Here, we revolutionize the analysis of microscopy images, extracting all the useful information theoretically contained in a complex microscope image. Using a generic, methodological approach, we extract the information by fitting experimental images with a detailed optical model of the microscope, a method we call parameter extraction from reconstructing images (PERI). As a proof of principle, we demonstrate this approach with a confocal image of colloidal spheres, improving measurements of particle positions and radii by 10-100 times over current methods and attaining the maximum possible accuracy. With this unprecedented accuracy, we measure nanometer-scale colloidal interactions in dense suspensions solely with light microscopy, a previously impossible feat. Our approach is generic and applicable to imaging methods from brightfield to electron microscopy, where we expect accuracies of 1 nm and 0.1 pm, respectively.

Contributed review: Review of integrated correlative light and electron microscopy.

PubMed

Timmermans, F J; Otto, C

2015-01-01

New developments in the field of microscopy enable to acquire increasing amounts of information from large sample areas and at an increased resolution. Depending on the nature of the technique, the information may reveal morphological, structural, chemical, and still other sample characteristics. In research fields, such as cell biology and materials science, there is an increasing demand to correlate these individual levels of information and in this way to obtain a better understanding of sample preparation and specific sample properties. To address this need, integrated systems were developed that combine nanometer resolution electron microscopes with optical microscopes, which produce chemically or label specific information through spectroscopy. The complementary information from electron microscopy and light microscopy presents an opportunity to investigate a broad range of sample properties in a correlated fashion. An important part of correlating the differences in information lies in bridging the different resolution and image contrast features. The trend to analyse samples using multiple correlated microscopes has resulted in a new research field. Current research is focused, for instance, on (a) the investigation of samples with nanometer scale distribution of inorganic and organic materials, (b) live cell analysis combined with electron microscopy, and (c) in situ spectroscopic and electron microscopy analysis of catalytic materials, but more areas will benefit from integrated correlative microscopy.

Acquisition of a High Resolution Field Emission Scanning Electron Microscope for the Analysis of Returned Samples

NASA Technical Reports Server (NTRS)

Nittler, Larry R.

2003-01-01

This grant furnished funds to purchase a state-of-the-art scanning electron microscope (SEM) to support our analytical facilities for extraterrestrial samples. After evaluating several instruments, we purchased a JEOL 6500F thermal field emission SEM with the following analytical accessories: EDAX energy-dispersive x-ray analysis system with fully automated control of instrument and sample stage; EDAX LEXS wavelength-dispersive x-ray spectrometer for high sensitivity light-element analysis; EDAX/TSL electron backscatter diffraction (EBSD) system with software for phase identification and crystal orientation mapping; Robinson backscatter electron detector; and an in situ micro-manipulator (Kleindiek). The total price was $550,000 (with $150,000 of the purchase supported by Carnegie institution matching funds). The microscope was delivered in October 2002, and most of the analytical accessories were installed by January 2003. With the exception of the wavelength spectrometer (which has been undergoing design changes) everything is working well and the SEM is in routine use in our laboratory.

Preparation of polymeric Janus particles by directional UV-induced reactions.

PubMed

Liu, Lianying; Ren, Mingwei; Yang, Wantai

2009-09-15

Polymeric Janus particles are obtained by UV-induced selective surface grafting polymerizations and coupling reactions, in virtue of the light-absorption of photoreactive materials such as the immobilized photoinitiator and spread photoinitiator solution on the surfaces exposed to UV light and the sheltering of densely arrayed immovable particles from light. Varying the monomers or macromolecules applied in photografting polymerization or coupling reaction, and choosing diverse polymeric particles of various size, bicolor and amphiphilic Janus particles could be successfully achieved. Observations by fluorescence microscope, scanning electron microscope ,and transmission electron microscope confirmed the asymmetrical morphology of the resultant Janus particles.

Film thickness measurement based on nonlinear phase analysis using a Linnik microscopic white-light spectral interferometer.

PubMed

Guo, Tong; Chen, Zhuo; Li, Minghui; Wu, Juhong; Fu, Xing; Hu, Xiaotang

2018-04-20

Based on white-light spectral interferometry and the Linnik microscopic interference configuration, the nonlinear phase components of the spectral interferometric signal were analyzed for film thickness measurement. The spectral interferometric signal was obtained using a Linnik microscopic white-light spectral interferometer, which includes the nonlinear phase components associated with the effective thickness, the nonlinear phase error caused by the double-objective lens, and the nonlinear phase of the thin film itself. To determine the influence of the effective thickness, a wavelength-correction method was proposed that converts the effective thickness into a constant value; the nonlinear phase caused by the effective thickness can then be determined and subtracted from the total nonlinear phase. A method for the extraction of the nonlinear phase error caused by the double-objective lens was also proposed. Accurate thickness measurement of a thin film can be achieved by fitting the nonlinear phase of the thin film after removal of the nonlinear phase caused by the effective thickness and by the nonlinear phase error caused by the double-objective lens. The experimental results demonstrated that both the wavelength-correction method and the extraction method for the nonlinear phase error caused by the double-objective lens improve the accuracy of film thickness measurements.

21 CFR 864.3600 - Microscopes and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... enlarge images of specimens, preparations, and cultures for medical purposes. Variations of microscopes... light. (3) Inverted stage microscopes, which permit examination of tissue cultures or other biological...

Mechanism of Prism-Coupled Scanning Tunneling Microscope Light Emission

NASA Astrophysics Data System (ADS)

Iida, Wataru; Ahamed, Jamal U.; Katano, Satoshi; Uehara, Yoichi

2011-09-01

We have investigated the mechanism of scanning tunneling microscope light emission (STM-LE) in a prism-coupled configuration using finite difference time domain analysis. In this configuration, the sample is a metallic thin film evaporated on the bottom surface of a hemispherical glass prism. STM light emitted into the prism (prism-side emission) through the metallic film is measured. Since both localized surface plasmons (LSP) and surface plasmon polaritons (SPP) contribute to prism-side emission, this emission is stronger than that in conventional STM-LE measured from the sample surface side, which is radiated by LSP alone. We show that the spatial resolution of prism-side emission is determined not by the propagation length of SPP, but by the lateral size of LSP, similarly to conventional (i.e., tip side) STM-LE. Thus, we conclude that, by using the prism-coupled configuration, the signal level of STM-LE improves without the loss of spatial resolution attained in tip side emission.

Structured light optical microscopy for three-dimensional reconstruction of technical surfaces

NASA Astrophysics Data System (ADS)

Kettel, Johannes; Reinecke, Holger; Müller, Claas

2016-04-01

In microsystems technology quality control of micro structured surfaces with different surface properties is playing an ever more important role. The process of quality control incorporates three-dimensional (3D) reconstruction of specularand diffusive reflecting technical surfaces. Due to the demand on high measurement accuracy and data acquisition rates, structured light optical microscopy has become a valuable solution to solve this problem providing high vertical and lateral resolution. However, 3D reconstruction of specular reflecting technical surfaces still remains a challenge to optical measurement principles. In this paper we present a measurement principle based on structured light optical microscopy which enables 3D reconstruction of specular- and diffusive reflecting technical surfaces. It is realized using two light paths of a stereo microscope equipped with different magnification levels. The right optical path of the stereo microscope is used to project structured light onto the object surface. The left optical path is used to capture the structured illuminated object surface with a camera. Structured light patterns are generated by a Digital Light Processing (DLP) device in combination with a high power Light Emitting Diode (LED). Structured light patterns are realized as a matrix of discrete light spots to illuminate defined areas on the object surface. The introduced measurement principle is based on multiple and parallel processed point measurements. Analysis of the measured Point Spread Function (PSF) by pattern recognition and model fitting algorithms enables the precise calculation of 3D coordinates. Using exemplary technical surfaces we demonstrate the successful application of our measurement principle.

Virtual microscopes in podiatric medical education.

PubMed

Becker, John H

2006-01-01

In many medical schools, microscopes are being replaced as teaching tools by computers with software that emulates the use of a light microscope. This article chronicles the adoption of "virtual microscopes" by a podiatric medical school and presents the results of educational research on the effectiveness of this adoption in a histology course. If the trend toward virtual microscopy in education continues, many 21st-century physicians will not be trained to operate a light microscope. The replacement of old technologies by new is discussed. The fundamental question is whether all podiatric physicians should be trained in the use of a particular tool or only those who are likely to use it in their own practice.

A high-resolution multimode digital microscope system.

PubMed

Salmon, Edward D; Shaw, Sidney L; Waters, Jennifer C; Waterman-Storer, Clare M; Maddox, Paul S; Yeh, Elaine; Bloom, Kerry

2013-01-01

This chapter describes the development of a high-resolution, multimode digital imaging system based on a wide-field epifluorescent and transmitted light microscope, and a cooled charge-coupled device (CCD) camera. The three main parts of this imaging system are Nikon FXA microscope, Hamamatsu C4880 cooled CCD camera, and MetaMorph digital imaging system. This chapter presents various design criteria for the instrument and describes the major features of the microscope components-the cooled CCD camera and the MetaMorph digital imaging system. The Nikon FXA upright microscope can produce high resolution images for both epifluorescent and transmitted light illumination without switching the objective or moving the specimen. The functional aspects of the microscope set-up can be considered in terms of the imaging optics, the epi-illumination optics, the transillumination optics, the focus control, and the vibration isolation table. This instrument is somewhat specialized for microtubule and mitosis studies, and it is also applicable to a variety of problems in cellular imaging, including tracking proteins fused to the green fluorescent protein in live cells. The instrument is also valuable for correlating the assembly dynamics of individual cytoplasmic microtubules (labeled by conjugating X-rhodamine to tubulin) with the dynamics of membranes of the endoplasmic reticulum (labeled with DiOC6) and the dynamics of the cell cortex (by differential interference contrast) in migrating vertebrate epithelial cells. This imaging system also plays an important role in the analysis of mitotic mutants in the powerful yeast genetic system Saccharomyces cerevisiae. Copyright © 1998 Elsevier Inc. All rights reserved.

Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging

NASA Astrophysics Data System (ADS)

Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

2018-01-01

We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis.

Spectral confocal reflection microscopy using a white light source

NASA Astrophysics Data System (ADS)

Booth, M.; Juškaitis, R.; Wilson, T.

2008-08-01

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.

Novel instrumentation for multifield time-lapse cinemicrography.

PubMed

Kallman, R F; Blevins, N; Coyne, M A; Prionas, S D

1990-04-01

The most significant feature of the system that is described is its ability to image essentially simultaneously the growth of up to 99 single cells into macroscopic colonies, each in its own microscope field. Operationally, fields are first defined and programmed by a trained observer. All subsequent steps are automatic and under computer control. Salient features of the hardware are stepper motor-controlled movement of the stage and fine adjustment of an inverted microscope, a high-quality 16-mm cine camera with light meter and controls, and a miniature incubator in which cells may be grown under defined conditions directly on the microscope stage. This system, termed MUTLAS, necessitates reordering of the primary images by rephotographing them on fresh film. Software developed for the analysis of cell and colony growth requires frame-by-frame examination of the secondary film and the use of a mouse-driven cursor to trace microscopically visible (4X objective magnification) events.

Light field imaging and application analysis in THz

NASA Astrophysics Data System (ADS)

Zhang, Hongfei; Su, Bo; He, Jingsuo; Zhang, Cong; Wu, Yaxiong; Zhang, Shengbo; Zhang, Cunlin

2018-01-01

The light field includes the direction information and location information. Light field imaging can capture the whole light field by single exposure. The four-dimensional light field function model represented by two-plane parameter, which is proposed by Levoy, is adopted in the light field. Acquisition of light field is based on the microlens array, camera array and the mask. We calculate the dates of light-field to synthetize light field image. The processing techniques of light field data include technology of refocusing rendering, technology of synthetic aperture and technology of microscopic imaging. Introducing the technology of light field imaging into THz, the efficiency of 3D imaging is higher than that of conventional THz 3D imaging technology. The advantages compared with visible light field imaging include large depth of field, wide dynamic range and true three-dimensional. It has broad application prospects.

Application of microscopy in authentication of traditional Tibetan medicinal plants of five Rhodiola (Crassulaceae) alpine species by comparative anatomy and micromorphology.

PubMed

Li, Tao; Zhang, Hao

2008-06-01

A comparative analysis was undertaken to conduct an anatomical and micromorphological study of five species of Rhodiola-R. kirilowii, R. yunnanensis, R. crenulata, R. fastigata, and R. quadrifida-collected from the western Sichuan province plateau of China. Rhodiola plants are a popularly used ethnodrug from the Qinghai-Tibetan plateau of China. Modern studies have shown that the plants of Rhodiola possess different pharmacological activities, chemical constituents, and efficiencies in clinical application. To distinguish five main species of Rhodiola and ensure their safety and efficacy, microscopic characteristics of roots, rhizomes, and stems, including transverse sections, stem and foliar epidermis, as well as the crude drug powder, were observed. The fixed, sectioned, and stained plant materials, as well as the crude powder, were studied using a light microscope according to the usual microscopic techniques. The results of the microscopic features were systematically and comparatively described and illustrated. The five species have distinct microscopic characteristic differences, thus allowing us to distinguish between the species. Also, semi-quantitative and quantitative micrographic parameter tables were simultaneously presented. Further, a key to the five species and a comparative chart of the key authentication parameters based on these anatomic characteristics analyzed was drawn up and is presented for the Rhodiola species studied. The study indicated that light microscopy and related techniques provide a method that is convenient, feasible, and can be unambiguously applied to the authentication of species of Rhodiola. (c) 2008 Wiley-Liss, Inc.

Methyl green and nitrotetrazolium blue chloride co-expression in colon tissue: A hyperspectral microscopic imaging analysis

NASA Astrophysics Data System (ADS)

Li, Qingli; Liu, Hongying; Wang, Yiting; Sun, Zhen; Guo, Fangmin; Zhu, Jianzhong

2014-12-01

Histological observation of dual-stained colon sections is usually performed by visual observation under a light microscope, or by viewing on a computer screen with the assistance of image processing software in both research and clinical settings. These traditional methods are usually not sufficient to reliably differentiate spatially overlapping chromogens generated by different dyes. Hyperspectral microscopic imaging technology offers a solution for these constraints as the hyperspectral microscopic images contain information that allows differentiation between spatially co-located chromogens with similar but different spectra. In this paper, a hyperspectral microscopic imaging (HMI) system is used to identify methyl green and nitrotetrazolium blue chloride in dual-stained colon sections. Hyperspectral microscopic images are captured and the normalized score algorithm is proposed to identify the stains and generate the co-expression results. Experimental results show that the proposed normalized score algorithm can generate more accurate co-localization results than the spectral angle mapper algorithm. The hyperspectral microscopic imaging technology can enhance the visualization of dual-stained colon sections, improve the contrast and legibility of each stain using their spectral signatures, which is helpful for pathologist performing histological analyses.

7 CFR 353.9 - Standards for accreditation of non-government facilities to perform laboratory seed health...

Code of Federal Regulations, 2013 CFR

2013-01-01

... seed requires a stereo microscope. Visual examination of tissue requires a compound light microscope... equipment; fluorescent microscopes; plate readers; spectrophotometers; and the appropriate assay materials...

7 CFR 353.9 - Standards for accreditation of non-government facilities to perform laboratory seed health...

Code of Federal Regulations, 2011 CFR

2011-01-01

... seed requires a stereo microscope. Visual examination of tissue requires a compound light microscope... equipment; fluorescent microscopes; plate readers; spectrophotometers; and the appropriate assay materials...

7 CFR 353.9 - Standards for accreditation of non-government facilities to perform laboratory seed health...

Code of Federal Regulations, 2010 CFR

2010-01-01

... seed requires a stereo microscope. Visual examination of tissue requires a compound light microscope... equipment; fluorescent microscopes; plate readers; spectrophotometers; and the appropriate assay materials...

7 CFR 353.9 - Standards for accreditation of non-government facilities to perform laboratory seed health...

Code of Federal Regulations, 2014 CFR

2014-01-01

... seed requires a stereo microscope. Visual examination of tissue requires a compound light microscope... equipment; fluorescent microscopes; plate readers; spectrophotometers; and the appropriate assay materials...

Compact Video Microscope Imaging System Implemented in Colloid Studies

NASA Technical Reports Server (NTRS)

McDowell, Mark

2002-01-01

Long description Photographs showing fiber-optic light source, microscope and charge-coupled discharge (CCD) camera head connected to camera body, CCD camera body feeding data to image acquisition board in PC, and Cartesian robot controlled via PC board. The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. CMIS can be used in situ with a minimum amount of user intervention. This system can scan, find areas of interest in, focus on, and acquire images automatically. Many multiple-cell experiments require microscopy for in situ observations; this is feasible only with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control. The software also has a user-friendly interface, which can be used independently of the hardware for further post-experiment analysis. CMIS has been successfully developed in the SML Laboratory at the NASA Glenn Research Center and adapted for use for colloid studies and is available for telescience experiments. The main innovations this year are an improved interface, optimized algorithms, and the ability to control conventional full-sized microscopes in addition to compact microscopes. The CMIS software-hardware interface is being integrated into our SML Analysis package, which will be a robust general-purpose image-processing package that can handle over 100 space and industrial applications.

Microscopic theory of light-induced deformation in amorphous side-chain azobenzene polymers.

PubMed

Toshchevikov, V; Saphiannikova, M; Heinrich, G

2009-04-16

We propose a microscopic theory of light-induced deformation of side-chain azobenzene polymers taking into account the internal structure of polymer chains. Our theory is based on the fact that interaction of chromophores with the polarized light leads to the orientation anisotropy of azobenzene macromolecules which is accompanied by the appearance of mechanical stress. It is the first microscopic theory which provides the value of the light-induced stress larger than the yield stress. This result explains a possibility for the inscription of surface relief gratings in glassy side-chain azobenzene polymers. For some chemical architectures, elongation of a sample demonstrates a nonmonotonic behavior with the light intensity and can change its sign (a stretched sample starts to be uniaxially compressed), in agreement with experiments. Using a viscoplastic approach, we show that the irreversible strain of a sample, which remains after the light is switched off, decreases with increasing temperature and can disappear at certain temperature below the glass transition temperature. This theoretical prediction is also confirmed by recent experiments.

Rapid identification of Salmonella serotypes through hyperspectral microscopy with different lighting sources

USDA-ARS?s Scientific Manuscript database

Hyperspectral microscope imaging (HMI) has the potential to classify foodborne pathogenic bacteria at cell level by combining microscope images with a spectrophotometer. In this study, the spectra generated from HMIs of five live Salmonella serovars from two light sources, metal halide (MH) and tun...

Development of and Clinical Experience with a Simple Device for Performing Intraoperative Fluorescein Fluorescence Cerebral Angiography: Technical Notes.

PubMed

Ichikawa, Tsuyoshi; Suzuki, Kyouichi; Watanabe, Yoichi; Sato, Taku; Sakuma, Jun; Saito, Kiyoshi

2016-01-01

To perform intraoperative fluorescence angiography (FAG) under a microscope without an integrated FAG function with reasonable cost and sufficient quality for evaluation, we made a small and easy to use device for fluorescein FAG (FAG filter). We investigated the practical use of this FAG filter during aneurysm surgery, revascularization surgery, and brain tumor surgery. The FAG filter consists of two types of filters: an excitatory filter and a barrier filter. The excitatory filter excludes all wavelengths except for blue light and the barrier filter passes long waves except for blue light. By adding this FAG filter to a microscope without an integrated FAG function, light from the microscope illuminating the surgical field becomes blue, which is blocked by the barrier filter. We put the FAG filter on the objective lens of the operating microscope correctly and fluorescein sodium was injected intravenously or intra-arterially. Fluorescence (green light) from vessels in the surgical field and the dyed tumor were clearly observed through the microscope and recorded by a memory device. This method was easy and could be performed in a short time (about 10 seconds). Blood flow of small vessels deep in the surgical field could be observed. Blood flow stagnation could be evaluated. However, images from this method were inferior to those obtained by currently commercially available microscopes with an integrated FAG function. In brain tumor surgery, a stained tumor on the brain surface could be observed using this method. FAG could be performed with a microscope without an integrated FAG function easily with only this FAG filter.

Development of and Clinical Experience with a Simple Device for Performing Intraoperative Fluorescein Fluorescence Cerebral Angiography: Technical Notes

PubMed Central

ICHIKAWA, Tsuyoshi; SUZUKI, Kyouichi; WATANABE, Yoichi; SATO, Taku; SAKUMA, Jun; SAITO, Kiyoshi

2016-01-01

To perform intraoperative fluorescence angiography (FAG) under a microscope without an integrated FAG function with reasonable cost and sufficient quality for evaluation, we made a small and easy to use device for fluorescein FAG (FAG filter). We investigated the practical use of this FAG filter during aneurysm surgery, revascularization surgery, and brain tumor surgery. The FAG filter consists of two types of filters: an excitatory filter and a barrier filter. The excitatory filter excludes all wavelengths except for blue light and the barrier filter passes long waves except for blue light. By adding this FAG filter to a microscope without an integrated FAG function, light from the microscope illuminating the surgical field becomes blue, which is blocked by the barrier filter. We put the FAG filter on the objective lens of the operating microscope correctly and fluorescein sodium was injected intravenously or intra-arterially. Fluorescence (green light) from vessels in the surgical field and the dyed tumor were clearly observed through the microscope and recorded by a memory device. This method was easy and could be performed in a short time (about 10 seconds). Blood flow of small vessels deep in the surgical field could be observed. Blood flow stagnation could be evaluated. However, images from this method were inferior to those obtained by currently commercially available microscopes with an integrated FAG function. In brain tumor surgery, a stained tumor on the brain surface could be observed using this method. FAG could be performed with a microscope without an integrated FAG function easily with only this FAG filter. PMID:26597335

Aqueous carrier waveguide in a flow cytometer

DOEpatents

Mariella, Jr., Raymond P.; van den Engh, Gerrit; Northrup, M. Allen

1995-01-01

The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified.

Miniature self-contained vacuum compatible electronic imaging microscope

DOEpatents

Naulleau, Patrick P.; Batson, Phillip J.; Denham, Paul E.; Jones, Michael S.

2001-01-01

A vacuum compatible CCD-based microscopic camera with an integrated illuminator. The camera can provide video or still feed from the microscope contained within a vacuum chamber. Activation of an optional integral illuminator can provide light to illuminate the microscope subject. The microscope camera comprises a housing with a objective port, modified objective, beam-splitter, CCD camera, and LED illuminator.

Quantitative luminescence imaging system

DOEpatents

Erwin, D.N.; Kiel, J.L.; Batishko, C.R.; Stahl, K.A.

1990-08-14

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopic imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber. 22 figs.

Design considerations of a real-time clinical confocal microscope

NASA Astrophysics Data System (ADS)

Masters, Barry R.

1991-06-01

A real-time clinical confocal light microscope provides the ophthalmologist with a new tool for the observation of the cornea and the ocular lens. In addition, the ciliary body, the iris, and the sclera can be observed. The real-time light microscopic images have high contrast and resolution. The transverse resolution is about one half micron and the range resolution is one micron. The following observations were made with visible light: corneal epithelial cells, wing cells, basal cells, Bowman's membrane, nerve fibers, basal lamina, fibroblast nuclei, Descemet's membrane, endothelial cells. Observation of the in situ ocular lens showed lens capsule, lens epithelium, lens fibrils, the interior of lens fibrils. The applications of the confocal microscope include: eye banking, laser refractive surgery, observation of wound healing, observation of the iris, the sciera, the ciliary body, the ocular lens, and the intraocular lens. Digital image processing can produce three-dimensional reconstructions of the cornea and the ocular lens.

[Clinical pathology on the verge of virtual microscopy].

PubMed

Tolonen, Teemu; Näpänkangas, Juha; Isola, Jorma

2015-01-01

For more than 100 years, examinations of pathology specimens have relied on the use of the light microscope. The technological progress of the last few years is enabling the digitizing of histologic specimen slides and application of the virtual microscope in diagnostics. Virtual microscopy will facilitate consultation possibilities, and digital image analysis serves to enhance the level of diagnostics. Organizing and monitoring clinicopathological meetings will become easier. Digital archive of histologic specimens and the virtual microscopy network are expected to benefit training and research as well, particularly what applies to the Finnish biobank network which is currently being established.

Proper alignment of the microscope.

PubMed

Rottenfusser, Rudi

2013-01-01

The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights reserved.

Faster and less phototoxic 3D fluorescence microscopy using a versatile compressed sensing scheme

PubMed Central

Woringer, Maxime; Darzacq, Xavier; Zimmer, Christophe

2017-01-01

Three-dimensional fluorescence microscopy based on Nyquist sampling of focal planes faces harsh trade-offs between acquisition time, light exposure, and signal-to-noise. We propose a 3D compressed sensing approach that uses temporal modulation of the excitation intensity during axial stage sweeping and can be adapted to fluorescence microscopes without hardware modification. We describe implementations on a lattice light sheet microscope and an epifluorescence microscope, and show that images of beads and biological samples can be reconstructed with a 5-10 fold reduction of light exposure and acquisition time. Our scheme opens a new door towards faster and less damaging 3D fluorescence microscopy. PMID:28788909

Miniaturized integration of a fluorescence microscope

PubMed Central

Ghosh, Kunal K.; Burns, Laurie D.; Cocker, Eric D.; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J.

2013-01-01

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals towards relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including semiconductor light source and sensor. This device enables high-speed cellular-level imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens. PMID:21909102

Miniaturized integration of a fluorescence microscope.

PubMed

Ghosh, Kunal K; Burns, Laurie D; Cocker, Eric D; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J

2011-09-11

The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals for relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including a semiconductor light source and sensor. This device enables high-speed cellular imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens.

Standardization for Ki-67 Assessment in Moderately Differentiated Breast Cancer. A Retrospective Analysis of the SAKK 28/12 Study

PubMed Central

Varga, Zsuzsanna; Cassoly, Estelle; Li, Qiyu; Oehlschlegel, Christian; Tapia, Coya; Lehr, Hans Anton; Klingbiel, Dirk; Thürlimann, Beat; Ruhstaller, Thomas

2015-01-01

Background Proliferative activity (Ki-67 Labelling Index) in breast cancer increasingly serves as an additional tool in the decision for or against adjuvant chemotherapy in midrange hormone receptor positive breast cancer. Ki-67 Index has been previously shown to suffer from high inter-observer variability especially in midrange (G2) breast carcinomas. In this study we conducted a systematic approach using different Ki-67 assessments on large tissue sections in order to identify the method with the highest reliability and the lowest variability. Materials and Methods Five breast pathologists retrospectively analyzed proliferative activity of 50 G2 invasive breast carcinomas using large tissue sections by assessing Ki-67 immunohistochemistry. Ki-67-assessments were done on light microscopy and on digital images following these methods: 1) assessing five regions, 2) assessing only darkly stained nuclei and 3) considering only condensed proliferative areas (‘hotspots’). An individual review (the first described assessment from 2008) was also performed. The assessments on light microscopy were done by estimating. All measurements were performed three times. Inter-observer and intra-observer reliabilities were calculated using the approach proposed by Eliasziw et al. Clinical cutoffs (14% and 20%) were tested using Fleiss’ Kappa. Results There was a good intra-observer reliability in 5 of 7 methods (ICC: 0.76–0.89). The two highest inter-observer reliability was fair to moderate (ICC: 0.71 and 0.74) in 2 methods (region-analysis and individual-review) on light microscopy. Fleiss’-kappa-values (14% cut-off) were the highest (moderate) using the original recommendation on light-microscope (Kappa 0.58). Fleiss’ kappa values (20% cut-off) were the highest (Kappa 0.48 each) in analyzing hotspots on light-microscopy and digital-analysis. No methodologies using digital-analysis were superior to the methods on light microscope. Conclusion Our results show that all methods on light-microscopy for Ki-67 assessment in large tissue sections resulted in a good intra-observer reliability. Region analysis and individual review (the original recommendation) on light-microscopy yielded the highest inter-observer reliability. These results show slight improvement to previously published data on poor-reproducibility and thus might be a practical-pragmatic way for routine assessment of Ki-67 Index in G2 breast carcinomas. PMID:25885288

Sample holder for axial rotation of specimens in 3D microscopy.

PubMed

Bruns, T; Schickinger, S; Schneckenburger, H

2015-10-01

In common light microscopy, observation of samples is only possible from one perspective. However, especially for larger three-dimensional specimens observation from different views is desirable. Therefore, we are presenting a sample holder permitting rotation of the specimen around an axis perpendicular to the light path of the microscope. Thus, images can be put into a defined multidimensional context, enabling reliable three-dimensional reconstructions. The device can be easily adapted to a great variety of common light microscopes and is suitable for various applications in science, education and industry, where the observation of three-dimensional specimens is essential. Fluorescence z-projection images of copepods and ixodidae ticks at different rotation angles obtained by confocal laser scanning microscopy and light sheet fluorescence microscopy are reported as representative results. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Color digital lensless holographic microscopy: laser versus LED illumination.

PubMed

Garcia-Sucerquia, Jorge

2016-08-20

A comparison of the performance of color digital lensless holographic microscopy (CDLHM) as utilized for illumination of RGB lasers or a super-bright white-light LED with a set of spectral filters is presented. As the use of lasers in CDLHM conceals the possibility of having a compact, lightweight, portable, and low cost microscope, and additionally the limited available laser radiation wavelengths limit a real multispectral imaging microscope, here we present the use of super-bright white-light LED and spectral filters for illuminating the sample. The performance of RGB laser-CDLHM and LED-CDLHM is evaluated on imaging a section of the head of a Drosophila melanogaster fly. This comparison shows that there is trade-off between the spatial resolution of the microscope and the light sources utilized, which can be understood with regard to the coherence properties of the illuminating light. Despite the smaller spatial coherence features of LED-CDLHM in comparison with laser-CDLHM, the former shows promise as a portable RGB digital lensless holographic microscope that could be extended to other wavelengths by the use of different spectral filters.

Microscopical and functional aspects of calcium-transport and deposition in terrestrial isopods.

PubMed

Ziegler, Andreas; Fabritius, Helge; Hagedorn, Monica

2005-01-01

Terrestrial isopods (Crustacea) are excellent model organisms to study epithelial calcium-transport and the regulation of biomineralization processes. They molt frequently and resorb cuticular CaCO(3) before the molt to prevent excessive loss of Ca(2+) ions when the old cuticle is shed. The resorbed mineral is stored in CaCO(3) deposits within the ecdysial gap of the first four anterior sternites. After the molt, the deposits are quickly resorbed to mineralise the posterior part of the new cuticle. The deposits contain numerous small spherules composed of an organic matrix and amorphous CaCO(3), which has a high solubility and, therefore, facilitates quick mobilization of Ca(2+) and HCO(3)(-) ions. During the formation and resorption of the deposits large amounts of Ca(2+), HCO(3)(-) and H(+) are transported across the anterior sternal epithelial cells. Within the last years, various light and electron microscopical techniques have been used to characterize the CaCO(3) deposits and the cellular mechanisms involved in biomineralization. The work on the CaCO(3) deposits includes studies on the ultrastructure of the deposits, the sequence of events during deposit formation and dissolution, and the mineral composition of the sternal deposits. The differentiation of the anterior sternal epithelial cells and the mechanisms of epithelial ion transport required for the mineralization and demineralisation of the deposits was studied using various analytical light and electron microscopical techniques including polarized light microscopy, immunocytochemistry, electron microprobe analysis, electron energy loss spectroscopy and electron spectroscopic imaging. Comparative analysis of deposit morphology and the differentiation of the sternal epithelia provide information on the evolution of CaCO(3) deposit formation in relation to the degree of adaptation to terrestrial environments.

Auricular burns associated with operating microscope use during otologic surgery.

PubMed

Latuska, Richard F; Carlson, Matthew L; Neff, Brian A; Driscoll, Colin L; Wanna, George B; Haynes, David S

2014-02-01

To raise awareness of the potential hazard of auricular burns associated with operating microscope use during otologic surgery. Retrospective case series and summary of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database of voluntary adverse event reports pertaining to microscope related auricular thermal injuries. All patients who sustained auricular burns while using the operating microscope during otologic surgery at 2 tertiary academic referral centers. Surgical procedure, microscope model, intensity of illumination, length of procedure, focal length, location and severity of burn, and patient outcome. A total of 4 microscope-related auricular thermal injuries were identified from the authors' institutions. Additionally, 82 unique cases of soft tissue burns associated with the use of an operative microscope have been voluntarily reported to the FDA since 2004. A disproportionately large percent (∼ 30%) of these occurred within the field of otology, the majority of which were during tympanoplasty or tympanomastoidectomy procedures at focal length distances of 300 mm or less with xenon light source microscopes. Simultaneous advancements in light delivery technologies and lens optics have continued to improve the efficiency of the operating microscope; however, these improvements also increase the potential for thermal injuries. Although rare, a review of the FDA MAUDE database suggests that microscope-related soft tissue burns occur more frequently in otology than any other surgical specialty. A variety of factors may help explain this finding, including the unique anatomy of the external ear with thin skin and limited underlying adipose tissue. Preventative measures should be taken to decrease the risk of thermal injuries including use of the lowest comfortable light intensity, adjusting the aperture width to match the operative field, frequent wound irrigation, and covering exposed portions of the pinna with a moist surgical sponge.

3D Reconstruction of Frozen Plant Tissue: a unique histological analysis to image post-freeze responses

USDA-ARS?s Scientific Manuscript database

Winter hardiness in plants is the result of a complex interaction between genes, the tissue where those genes are expressed and the environment. The light microscope is a valuable tool to understand this complexity which will ultimately help researchers improve the tolerance of plants to freezing st...

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

PubMed Central

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-01-01

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications. PMID:26525841

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope.

PubMed

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-11-03

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

NASA Astrophysics Data System (ADS)

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-11-01

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.

PubMed

Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

2018-01-01

We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Adding an extra dimension to what students see through the light microscope: a lab exercise demonstrating critical analysis for microscopy students.

PubMed

Garrill, Ashley

2011-01-01

This article describes an undergraduate lab exercise that demonstrates the importance of students thinking critically about what they see through a microscope. The students are given growth data from tip-growing organisms that suggest the cells grow in a pulsatile manner. The students then critique this data in several exercises that incorporate aspects of a problem-based learning approach, envisaging growth not just in two dimensions, but in three dimensions. For some cells, what appears to be pulsatile growth could also be explained by growth at a constant rate up and down in the z-axis. Depending on the diffraction pattern generated by the tip of the cell, this movement in the z-axis could go undetected. This raises the possibility that pulsatile growth seen in some species may be an artifact generated by the limitations of the light microscope. Students were subsequently asked to rate their awareness of the need to think critically about what they see through a microscope, using a scale of 1 (unaware) to 5 (very much aware). Prior to doing the lab exercise, the mean rating was 2.7; this increased to 4.4 after the lab. The students also indicated a likelihood of being more critical in their thinking in other aspects of their biology curriculum.

Foveal light exposure is increased at the time of removal of silicone oil with the potential for phototoxicity.

PubMed

Dogramaci, Mahmut; Williams, Katie; Lee, Ed; Williamson, Tom H

2013-01-01

There is sudden and dramatic visual function deterioration in 1-10 % of eyes filled with silicone oil at the time of removal of silicon oil. Transmission of high-energy blue light is increased in eyes filled with silicone oil. We sought to identify if increased foveal light exposure is a potential factor in the pathophysiology of the visual loss at the time of removal of silicone oil. A graphic ray tracing computer program and laboratory models were used to determine the effect of the intraocular silicone oil bubble size on the foveal illuminance at the time of removal of silicone oil under direct microscope light. The graphic ray tracing computer program revealed a range of optical vignetting effects created by different sizes of silicone oil bubble within the vitreous cavity giving rise to an uneven macular illumination. The laboratory model was used to quantify the variation of illuminance at the foveal region with different sizes of silicone oil bubble with in the vitreous cavity at the time of removal of silicon oil under direct microscope light. To substantiate the hypothesis of the light toxicity during removal of silicone oil, The outcome of oil removal procedures performed under direct microscope illumination in compared to those performed under blocked illumination. The computer program showed that the optical vignetting effect at the macula was dependent on the size of the intraocular silicone oil bubble. The laboratory eye model showed that the foveal illuminance followed a bell-shaped curve with 70 % greater illuminance demonstrated at with 50-60 % silicone oil fill. The clinical data identified five eyes with unexplained vision loss out of 114 eyes that had the procedure performed under direct microscope illumination compared to none out of 78 eyes that had the procedure under blocked illumination. Foveal light exposure, and therefore the potential for phototoxicity, is transiently increased at the time of removal of silicone oil. This is due to uneven macular illumination resulting from the optical vignetting effect of different silicone oil bubble sizes. The increase in foveal light exposure may be significant when the procedure is performed under bright operating microscope light on already stressed photoreceptors of an eye filled with silicon oil. We advocate the use of precautions, such as central shadow filter on the operating microscope light source to reduce foveal light exposure and the risk of phototoxicity at the time of removal of silicone oil. The graphic ray tracing computer program used in this study shows promise in eye modeling for future studies.

Remote microscopy and volumetric imaging on the surface of icy satellites

NASA Astrophysics Data System (ADS)

Soto, Alejandro; Nowicki, Keith; Howett, Carly; Feldkhun, Daniel; Retherford, Kurt D.

2017-10-01

With NASA PIDDP support we have applied recent advancements in Fourier-domain microscopy to develop an instrument capable of microscopic imaging from meter-scale distances for use on a planetary lander on the surface of an icy satellite or other planetary bodies. Without moving parts, our instrument projects dynamic patterns of laser light onto a distant target using a lightweight large-aperture reflector, which then collects the light scattered or fluoresced by the target on a fast photon-bucket detector. Using Fourier Transform based techniques, we reconstruct an image from the detected light. The remote microscope has been demonstrated to produce 2D images with better than 15 micron lateral resolution for targets at a distance of 5 meters and is capable of linearly proportionally higher resolution at shorter distances. The remote microscope is also capable of providing three-dimensional (3D) microscopic imaging capabilities, allowing future surface scientists to explore the morphology of microscopic features in surface ices, for example. The instrument enables microscopic in-situ imaging during day or night without the use of a robotic arm, greatly facilitating the surface operations for a lander or rover while expanding the area of investigation near a landing site for improved science targeting. We are developing this remote microscope for in-situ planetary exploration as a collaboration between the Southwest Research Institute, LambdaMetrics, and the University of Colorado.

Aqueous carrier waveguide in a flow cytometer

DOEpatents

Mariella, R.P. Jr.; Engh, G. van den; Northrup, M.A.

1995-12-12

The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified. 6 figs.

Fiber optic light collection system for scanning-tunneling-microscope-induced light emission.

PubMed

Watkins, Neil J; Long, James P; Kafafi, Zakya H; Mäkinen, Antti J

2007-05-01

We report a compact light collection scheme suitable for retrofitting a scanning tunneling microscope (STM) for STM-induced light emission experiments. The approach uses a pair of optical fibers with large core diameters and high numerical apertures to maximize light collection efficiency and to moderate the mechanical precision required for alignment. Bench tests indicate that efficiency reduction is almost entirely due to reflective losses at the fiber ends, while losses due to fiber misalignment have virtually been eliminated. Photon-map imaging with nanometer features is demonstrated on a stepped Au(111) surface with signal rates exceeding 10(4) counts/s.

Volumetric Light-field Encryption at the Microscopic Scale

PubMed Central

Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

2017-01-01

We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale. PMID:28059149

Volumetric Light-field Encryption at the Microscopic Scale

NASA Astrophysics Data System (ADS)

Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

2017-01-01

We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.

Microscope use in clinical veterinary practice and potential implications for veterinary school curricula.

PubMed

Stewart, Sherry M; Dowers, Kristy L; Cerda, Jacey R; Schoenfeld-Tacher, Regina M; Kogan, Lori R

2014-01-01

Microscopy (skill of using a microscope) and the concepts of cytology (study of cells) and histology (study of tissues) are most often taught in professional veterinary medicine programs through the traditional method of glass slides and light microscopes. Several limiting factors in veterinary training programs are encouraging educators to explore innovative options for teaching microscopy skills and the concepts of cytology and histology. An anonymous online survey was administered through the Colorado Veterinary Medical Association to Colorado veterinarians working in private practice. It was designed to assess their current usage of microscopes for cytological and histological evaluation of specimens and their perceptions of microscope use in their veterinary education. The first part of the survey was answered by 183 veterinarians, with 104 indicating they had an onsite diagnostic lab. Analysis pertaining to the use of the microscope in practice and in veterinary programs was conducted on this subset. Most respondents felt the amount of time spent in the curriculum using a microscope was just right for basic microscope use and using the microscope for viewing and learning about normal and abnormal histological sections and clinical cytology. Participants felt more emphasis could be placed on clinical and diagnostic cytology. Study results suggest that practicing veterinarians frequently use microscopes for a wide variety of cytological diagnostics. However, only two respondents indicated they prepared samples for histological evaluation. Veterinary schools should consider these results against the backdrop of pressure to implement innovative teaching techniques to meet the changing needs of the profession.

Bi-directional transmission of molecular information by photon or electron beams passing in the close vicinity of specific molecules, and its clinical and basic research applications: 1) Diagnosis of humans or animal patients without any direct contact; 2) Light microscopic and electron microscopic localization of neuro-transmitters, heavy metals, Oncogen C-fos (AB2), etc. of intracellular fine structures of normal and abnormal single cells using light or electro-microscopic indirect Bi-Digital O-Ring Test.

PubMed

Omura, Y; Losco, M; Omura, A K; Takeshige, C; Hisamitsu, T; Nakajima, H; Soejima, K; Yamamoto, S; Ishikawa, H; Kagoshima, T

1992-01-01

In 1985, Omura, Y. discovered that, when specific molecules were placed anywhere in the close vicinity of the path of a light beam (laser), their molecular information, as well as information on electrical & magnetic fields, is transmitted bi-directionally along the path of this light beam. Namely, this information is transmitted in the direction the light beam is projected and towards the direction from which the light beam is coming. This finding was applied to the following clinical and basic research: 1) In the past, using indirect Bi-Digital O-Ring Test, human or animal patients were diagnosed through an intermediate third person holding a good electrical conducting probe, the tip of which was touching the part of the patient to be examined. However, in order to diagnose the patient in isolation from a distance, or a dangerous or unmanagable unanesthesized animal, such as a lion or tiger, the author succeeded in making a diagnosis by replacing the metal conducting probe with a soft laser beam which is held by the one hand of the third person whose index finger is placed in close vicinity of the laser beam generated by a battery-powered penlight-type solid state laser generator. Thus, diagnosis within visible distance, without direct patient contact, became a reality. 2) Using a projection light microscope, by giving indirect Bi-Digital O-Ring Test while contacting with a fine electro-conductive probe on the magnified fine structure of normal and abnormal cells, various normal and abnormal intracellular substances were localized through a third person holding a pure reference control substance with the same hand that is holding the probe as an intermediary for the indirect Bi-Digital O-Ring Test. Instead of the photon beam in a light microscope, the author found that, using an electron beam passing through the close vicinity of specific molecules of specimens in an electron microscope, the molecular information is transmitted to the magnified fluorescent screen, and an indirect Bi-Digital O-Ring Test could be performed through a projected penlight-type solid state soft laser beam on the magnified intracellular structure through an observation glass window. Using the magnified fine structure of the cells, by either a light projection microscopic field or electron microscope, in various cancer cells of both humans and animals, Oncogen C-fos (AB2) and mercury were found inside of the nucleus. Integrin alpha 5 beta 1 was found on cell membranes and nuclear cell membranes of cancer cells. Acetylcholine was not found anywhere within cancer cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Differentiating characteristic microstructural features of cancerous tissues using Mueller matrix microscope.

PubMed

Wang, Ye; He, Honghui; Chang, Jintao; Zeng, Nan; Liu, Shaoxiong; Li, Migao; Ma, Hui

2015-12-01

Polarized light imaging can provide rich microstructural information of samples, and has been applied to the detections of various abnormal tissues. In this paper, we report a polarized light microscope based on Mueller matrix imaging by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission optical microscope. The maximum errors for the absolute values of Mueller matrix elements are reduced to 0.01 after calibration. This Mueller matrix microscope has been used to examine human cervical and liver cancerous tissues with fibrosis. Images of the transformed Mueller matrix parameters provide quantitative assessment on the characteristic features of the pathological tissues. Contrast mechanism of the experimental results are backed up by Monte Carlo simulations based on the sphere-cylinder birefringence model, which reveal the relationship between the pathological features in the cancerous tissues at the cellular level and the polarization parameters. Both the experimental and simulated data indicate that the microscopic transformed Mueller matrix parameters can distinguish the breaking down of birefringent normal tissues for cervical cancer, or the formation of birefringent surrounding structures accompanying the inflammatory reaction for liver cancer. With its simple structure, fast measurement and high precision, polarized light microscope based on Mueller matrix shows a good diagnosis application prospect. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transition of a dental histology course from light to virtual microscopy.

PubMed

Weaker, Frank J; Herbert, Damon C

2009-10-01

The transition of the dental histology course at the University of Texas Health Science Center at San Antonio Dental School was completed gradually over a five-year period. A pilot project was initially conducted to study the feasibility of integrating virtual microscopy into a traditional light microscopic lecture and laboratory course. Because of the difficulty of procuring quality calcified and decalcified sections of teeth, slides from the student loan collection in the oral histology block of the course were outsourced for conversion to digital images and placed on DVDs along with a slide viewer. The slide viewer mimicked the light microscope, allowing horizontal and vertical movement and changing of magnification, and, in addition, a feature to capture static images. In a survey, students rated the ease of use of the software, quality of the images, maneuverability of the images, and questions regarding use of the software, effective use of laboratory, and faculty time. Because of the positive support from the students, our entire student loan collection of 153 glass slides was subsequently converted to virtual images and distributed on an Apricorn pocket external hard drive. Students were asked to assess the virtual microscope over a four-year period. As a result of the surveys, light microscopes have been totally eliminated, and microscope exams have been replaced with project slide examinations. In the future, we plan to expand our virtual slides and incorporate computer testing.

Utility of fluorescence microscopy in embryonic/fetal topographical analysis.

PubMed

Zucker, R M; Elstein, K H; Shuey, D L; Ebron-McCoy, M; Rogers, J M

1995-06-01

For topographical analysis of developing embryos, investigators typically rely on scanning electron microscopy (SEM) to provide the surface detail not attainable with light microscopy. SEM is an expensive and time-consuming technique, however, and the preparation procedure may alter morphology and leave the specimen friable. We report that by using a high-resolution compound epifluorescence microscope with inexpensive low-power objectives and the fluorochrome acridine orange, we were able to obtain surface images of fixed or fresh whole rat embryos and fetal palates of considerably greater topographical detail than those obtained using routine light microscopy. Indeed the resulting high-resolution images afford not only superior qualitative documentation of morphological observations, but the capability for detailed morphometry via digitization and computer-assisted image analysis.

Comparative study viruses with computer-aided phase microscope AIRYSCAN

NASA Astrophysics Data System (ADS)

Tychinsky, Vladimir P.; Koufal, Georgy E.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.

1996-12-01

Traditionally viruses are studied with scanning electron microscopy (SEM) after complicated procedure of sample preparation without the possibility to study it under natural conditions. We obtained images of viruses (Vaccinia virus, Rotavirus) and rickettsias (Rickettsia provazekii, Coxiella burnetti) in native state with computer-aided phase microscope airyscan -- the interference microscope of Linnik layout with phase modulation of the reference wave with dissector image tube as coordinate-sensitive photodetector and computer processing of phase image. A light source was the He-Ne laser. The main result is coincidence of dimensions and shape of phase images with available information concerning their morphology obtained with SEM and other methods. The fine structure of surface and nuclei is observed. This method may be applied for virus recognition and express identification, investigation of virus structure and the analysis of cell-virus interaction.

Compact, light-weight and cost-effective microscope based on lensless incoherent holography for telemedicine applications.

PubMed

Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

2010-06-07

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing approximately 46 grams with dimensions smaller than 4.2 cm x 4.2 cm x 5.8 cm that achieves sub-cellular resolution over a large field of view of approximately 24 mm(2). This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings.

Evaluation of physical changes in wood during colonization by Ceriporiopsis submervispora

Treesearch

Chris Hunt; Alex Wiedenhoeft; Eric Horn; Carl Houtman

2001-01-01

Mechanical, chemical, and light microscopic methods were used to observe wood cell wall changes during colonization by Ceriporiopsis submervispora. Maximum crushing load, dynamic mechanical analysis (DMA), and quantitative Simon’s staining were found to be the most useful methods for tracking biopulping action. MOE and loss modulus trended downward within 2 days of...

Determination of morphological parameters of biological cells by analysis of scattered-light distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, D.E.

1979-11-01

The extraction of morphological parameters from biological cells by analysis of light-scatter patterns is described. A light-scattering measurement system has been designed and constructed that allows one to visually examine and photographically record biological cells or cell models and measure the light-scatter pattern of an individual cell or cell model. Using a laser or conventional illumination, the imaging system consists of a modified microscope with a 35 mm camera attached to record the cell image or light-scatter pattern. Models of biological cells were fabricated. The dynamic range and angular distributions of light scattered from these models was compared to calculatedmore » distributions. Spectrum analysis techniques applied on the light-scatter data give the sought after morphological cell parameters. These results compared favorably to shape parameters of the fabricated cell models confirming the mathematical model procedure. For nucleated biological material, correct nuclear and cell eccentricity as well as the nuclear and cytoplasmic diameters were determined. A method for comparing the flow equivalent of nuclear and cytoplasmic size to the actual dimensions is shown. This light-scattering experiment provides baseline information for automated cytology. In its present application, it involves correlating average size as measured in flow cytology to the actual dimensions determined from this technique. (ERB)« less

Biological Effects of Laser Radiation. Volume I. Review of the Literature on Biological Effects of Laser Radiation-to 1965.

DTIC Science & Technology

1978-10-17

because of the rapid progress made in laser technology to date. The use of the Laser Microprobe in spectrochemical analysis of the elements is based on...spectroscopy to vaporize microscopic amounts of samples for elemental analysis . On the other hand, the intense, highly monochromatic laser beam is being...employed as a light source for Raman spectroscopy to study molecular structure. These two uses of lasers in spectroscopic analysis have been sucessful

Retracing in correlative light electron microscopy: where is my object of interest?

PubMed

Hodgson, Lorna; Nam, David; Mantell, Judith; Achim, Alin; Verkade, Paul

2014-01-01

Correlative light electron microscopy (CLEM) combines the strengths of light and electron microscopy in a single experiment. There are many ways to perform a CLEM experiment and a variety of microscopy modalities can be combined either on separate instruments or as completely integrated solutions. In general, however, a CLEM experiment can be divided into three parts: probes, processing, and analysis. Most of the existing technologies are focussed around the development and use of probes or describe processing methodologies that explain or circumvent some of the compromises that need to be made when performing both light and electron microscopy on the same sample. So far, relatively little attention has been paid to the analysis part of CLEM experiments. Although it is an essential part of each CLEM experiment, it is usually a cumbersome manual process. Here, we briefly discuss each of the three above-mentioned steps, with a focus on the analysis part. We will also introduce an automated registration algorithm that can be applied to the analysis stage to enable the accurate registration of LM and EM images. This facilitates tracing back the right cell/object seen in the light microscope in the EM. © 2014 Elsevier Inc. All rights reserved.

The optics of microscope image formation.

PubMed

Wolf, David E

2013-01-01

Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

Microstructural study of the nickel-base alloy WAZ-20 using qualitative and quantitative electron optical techniques

NASA Technical Reports Server (NTRS)

Young, S. G.

1973-01-01

The NASA nickel-base alloy WAZ-20 was analyzed by advanced metallographic techniques to qualitatively and quantitatively characterize its phases and stability. The as-cast alloy contained primary gamma-prime, a coarse gamma-gamma prime eutectic, a gamma-fine gamma prime matrix, and MC carbides. A specimen aged at 870 C for 1000 hours contained these same constituents and a few widely scattered high W particles. No detrimental phases (such as sigma or mu) were observed. Scanning electron microscope, light metallography, and replica electron microscope methods are compared. The value of quantitative electron microprobe techniques such as spot and area analysis is demonstrated.

Improving confocal microscopy with solid-state semiconductor excitation sources

NASA Astrophysics Data System (ADS)

Sivers, Nelson L.

To efficiently excite the fluorescent dyes used in imaging biological samples with a confocal microscope, the wavelengths of the exciting laser must be near the fluorochrome absorption peak. However, this causes imaging problems when the fluorochrome absorption and emission spectra overlap significantly, i.e. have small Stokes shifts, which is the case for most fluorochromes that emit in the red to infrared. As a result, the reflected laser excitation cannot be distinguished from the information-containing fluorescence signal. However, cryogenically cooling the exciting laser diode enabled the laser emission wavelengths to be tuned to shorter wavelengths, decreasing the interference between the laser and the fluorochrome's fluorescence. This reduced the amount of reflected laser light in the confocal image. However, the cooled laser diode's shorter wavelength signal resulted in slightly less efficient fluorochrome excitation. Spectrophotometric analysis showed that as the laser diodes were cooled, their output power increased, which more than compensated for the lower fluorochrome excitation and resulted in significantly more intense fluorescence. Thus, by tuning the laser diode emission wavelengths away from the fluorescence signal, less reflected laser light and more fluorescence information reached the detector, creating images with better signal to noise ratios. Additionally, new, high, luminous flux, light-emitting diodes (LEDs) are now powerful enough to create confocal fluorescence signals comparable to those produced by the traditional laser excitation sources in fluorescence confocal microscopes. The broader LED spectral response effectively excited the fluorochrome, yet was spectrally limited enough for standard filter sets to separate the LED excitation from the fluorochrome fluorescence signal. Spectrophotometric analysis of the excitation and fluorescence spectra of several fluorochromes showed that high-powered, LED-induced fluorescence contained the same spectral information and could be more intense than that produced by lasers. An alternative, LED-based, confocal microscope is proposed in this thesis that would be capable of exciting multiple fluorochromes in a single specimen, producing images of several distinct cellular components simultaneously. The inexpensive, LED-based, confocal microscope would require lower peak excitation intensities to produce fluorescence signals equal to those produced by laser excitation, reducing cellular damage and slowing fluorochrome photobleaching.

Imaging arrangement and microscope

DOEpatents

Pertsinidis, Alexandros; Chu, Steven

2015-12-15

An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

A numerical analysis of the Born approximation for image formation modeling of differential interference contrast microscopy for human embryos

NASA Astrophysics Data System (ADS)

Trattner, Sigal; Feigin, Micha; Greenspan, Hayit; Sochen, Nir

2008-03-01

The differential interference contrast (DIC) microscope is commonly used for the visualization of live biological specimens. It enables the view of the transparent specimens while preserving their viability, being a non-invasive modality. Fertility clinics often use the DIC microscope for evaluation of human embryos quality. Towards quantification and reconstruction of the visualized specimens, an image formation model for DIC imaging is sought and the interaction of light waves with biological matter is examined. In many image formation models the light-matter interaction is expressed via the first Born approximation. The validity region of this approximation is defined in a theoretical bound which limits its use to very small specimens with low dielectric contrast. In this work the Born approximation is investigated via the Helmholtz equation, which describes the interaction between the specimen and light. A solution on the lens field is derived using the Gaussian Legendre quadrature formulation. This numerical scheme is considered both accurate and efficient and has shortened significantly the computation time as compared to integration methods that required a great amount of sampling for satisfying the Whittaker - Shannon sampling theorem. By comparing the numerical results with the theoretical values it is shown that the theoretical bound is not directly relevant to microscopic imaging and is far too limiting. The numerical exhaustive experiments show that the Born approximation is inappropriate for modeling the visualization of thick human embryos.

Phototoxic effects of an operating microscope on the ocular surface and tear film.

PubMed

Hwang, Hyung Bin; Kim, Hyun Seung

2014-01-01

We evaluated light exposure-induced dry eye syndrome by investigating the phototoxic effects of an operating microscope on the ocular surface and tear film in rabbits. Sixty eyes of 30 rabbits were divided into 3 groups based on the intensity of light exposure received from an operating microscope: Control group, no exposure to light; group A, 40,000-lx intensity for 30 minutes; and group B, 100,000-lx intensity for 30 minutes. To evaluate the potential damage to the ocular surface and tear film, Schirmer tests, rose bengal staining, and conjunctival impression cytology were performed before the light exposure and at 1, 3, and 5 days afterward. In addition, the expression of interleukin 1-beta was analyzed in tear samples. The expression of mucin 5AC was evaluated using immunofluorescence staining, and periodic acid-Schiff staining was conducted on conjunctival tissues. Corneal and conjunctival tissues were observed by means of electron microscopy. Potential damage to the ocular surface and tear film was found in the light-exposed groups as evidenced by decreased aqueous tear production, devitalized corneal and conjunctival epithelial cells, squamous metaplasia of conjunctival epithelial cells, decreased conjunctival goblet cell density, decreased expression of mucin 5AC, ultrastructural cellular damage to corneal and conjunctival tissues, and increased interleukin 1-beta expression in tears. This damage was more noticeable in group B than in group A (P < 0.05). Light exposure from an operating microscope had phototoxic effects on the ocular surface and tear film in this in vivo experiment. These changes seemed to intensify as the intensity of the light increased. Therefore, excessive light exposure during ophthalmic procedures could be a pathogenic factor in dry eye syndrome after a surgery is performed.

Optical filters for wavelength selection in fluorescence instrumentation.

PubMed

Erdogan, Turan

2011-04-01

Fluorescence imaging and analysis techniques have become ubiquitous in life science research, and they are poised to play an equally vital role in in vitro diagnostics (IVD) in the future. Optical filters are crucial for nearly all fluorescence microscopes and instruments, not only to provide the obvious function of spectral control, but also to ensure the highest possible detection sensitivity and imaging resolution. Filters make it possible for the sample to "see" light within only the absorption band, and the detector to "see" light within only the emission band. Without filters, the detector would not be able to distinguish the desired fluorescence from scattered excitation light and autofluorescence from the sample, substrate, and other optics in the system. Today the vast majority of fluorescence instruments, including the widely popular fluorescence microscope, use thin-film interference filters to control the spectra of the excitation and emission light. Hence, this unit emphasizes thin-film filters. After briefly introducing different types of thin-film filters and how they are made, the unit describes in detail different optical filter configurations in fluorescence instruments, including both single-color and multicolor imaging systems. Several key properties of thin-film filters, which can significantly affect optical system performance, are then described. In the final section, tunable optical filters are also addressed in a relative comparison.

In situ flat embedding of monolayers and cell relocation in the acrylic resin LR white for comparative light and electron microscopy studies.

PubMed

Steiner, M; Schöfer, C; Mosgoeller, W

1994-12-01

A simple and reliable method has been developed for the in situ LR White embedding of cell monolayers grown on glass cover-slips. Combined with cytochemical or immunological procedures, this technique allows light and/or electron microscopy investigations of a large number of cells in the same horizontal plane within a relatively short period of time. It can be applied to cells grown on microgrid finder cover-slips which allows a distinct site of even an individual cell of a monolayer to be studied at first at the light microscope level and subsequently at the electron microscope level. Hence, it is also suitable for controlling manipulation of single cells, followed by their serial sectioning after relocation in the electron microscope.

CW laser use in biomedical research and practice

NASA Astrophysics Data System (ADS)

Matthopoulos, D. P.

2003-04-01

The communication of humans with their surrouding is achieved through their senses and the related organs. Visual communication using the eyes is made possible because the various sources of light, natural i.e. the sun or the lightning, or artificial such as Lasers, emit electromagnetic radiation which is either reflected or scattered by surfaces. This radiation received by eyes is processed in the brain where the images of the environment are developed. The luminous processing can be either macro- or microscopic. The macroscopic processing is the result of light coming from the sun or from wide range lamps, while the microscopic results from light coming from wide range lamps, mercury lamps, lasers or electron beam. The microscopic processing is the subject we are dealing with in this presentation.

Visualization of Neutrophil Extracellular Traps and Fibrin Meshwork in Human Fibrinopurulent Inflammatory Lesions: III. Correlative Light and Electron Microscopic Study

PubMed Central

Onouchi, Takanori; Shiogama, Kazuya; Mizutani, Yasuyoshi; Takaki, Takashi; Tsutsumi, Yutaka

2016-01-01

Neutrophil extracellular traps (NETs) released from dead neutrophils at the site of inflammation represent webs of neutrophilic DNA stretches dotted with granule-derived antimicrobial proteins, including lactoferrin, and play important roles in innate immunity against microbial infection. We have shown the coexistence of NETs and fibrin meshwork in varied fibrinopurulent inflammatory lesions at both light and electron microscopic levels. In the present study, correlative light and electron microscopy (CLEM) employing confocal laser scanning microscopy and scanning electron microscopy was performed to bridge light and electron microscopic images of NETs and fibrin fibrils in formalin-fixed, paraffin-embedded, autopsied lung sections of legionnaire’s pneumonia. Lactoferrin immunoreactivity and 4'-6-diamidino-2-phenylindole (DAPI) reactivity were used as markers of NETs, and fibrin was probed by fibrinogen gamma chain. Of note is that NETs light microscopically represented as lactoferrin and DAPI-colocalized dots, 2.5 μm in diameter. CLEM gave super-resolution images of NETs and fibrin fibrils: “Dotted” NETs were ultrastructurally composed of fine filaments and masses of 58 nm-sized globular materials. A fibrin fibril consisted of clusters of smooth-surfaced filaments. NETs filaments (26 nm in diameter) were significantly thinner than fibrin filaments (295 nm in diameter). Of note is that CLEM was applicable to formalin-fixed, paraffin-embedded sections of autopsy material. PMID:27917008

Analysis of thin-film polymers using attenuated total internal reflection-Raman microspectroscopy.

PubMed

Tran, Willie; Tisinger, Louis G; Lavalle, Luis E; Sommer, André J

2015-01-01

Two methods commonly employed for molecular surface analysis and thin-film analysis of microscopic areas are attenuated total reflection infrared (ATR-IR) microspectroscopy and confocal Raman microspectroscopy. In the former method, the depth of the evanescent probe beam can be controlled by the wavelength of light, the angle of incidence, or the refractive index of the internal reflection element. Because the penetration depth is proportional to the wavelength of light, one could interrogate a smaller film thickness by moving from the mid-infrared region to the visible region employing Raman spectroscopy. The investigation of ATR Raman microspectroscopy, a largely unexplored technique available to Raman microspectroscopy, was carried out. A Renishaw inVia Raman microscope was externally modified and used in conjunction with a solid immersion lens (SIL) to perform ATR Raman experiments. Thin-film polymer samples were analyzed to explore the theoretical sampling depth for experiments conducted without the SIL, with the SIL, and with the SIL using evanescent excitation. The feasibility of micro-ATR Raman was examined by collecting ATR spectra from films whose thickness measured from 200 to 60 nm. Films of these thicknesses were present on a much thicker substrate, and features from the underlying substrate did not become visible until the thin film reached a thickness of 68 nm.

Williams configures the LMM

NASA Image and Video Library

2016-04-18

ISS047e066551 (04/18/2016) --- NASA astronaut Jeff Williams configures the station’s Light Microscopy Module (LMM), a modified commercial, highly flexible, state-of-the-art light imaging microscope facility that provides researchers with powerful diagnostic hardware and software. The LMM enables novel research of microscopic phenomena in microgravity, with the capability of remotely acquiring and downloading digital images and videos across many levels of magnification.

Compact and light-weight automated semen analysis platform using lensfree on-chip microscopy.

PubMed

Su, Ting-Wei; Erlinger, Anthony; Tseng, Derek; Ozcan, Aydogan

2010-10-01

We demonstrate a compact and lightweight platform to conduct automated semen analysis using a lensfree on-chip microscope. This holographic on-chip imaging platform weighs ∼46 g, measures ∼4.2 × 4.2 × 5.8 cm, and does not require any lenses, lasers or other bulky optical components to achieve phase and amplitude imaging of sperms over ∼24 mm(2) field-of-view with an effective numerical aperture of ∼0.2. Using this wide-field lensfree on-chip microscope, semen samples are imaged for ∼10 s, capturing a total of ∼20 holographic frames. Digital subtraction of these consecutive lensfree frames, followed by appropriate processing of the reconstructed images, enables automated quantification of the count, the speed and the dynamic trajectories of motile sperms, while summation of the same frames permits counting of immotile sperms. Such a compact and lightweight automated semen analysis platform running on a wide-field lensfree on-chip microscope could be especially important for fertility clinics, personal male fertility tests, as well as for field use in veterinary medicine such as in stud farming and animal breeding applications.

Light Microscopy Microscope Experiment

NASA Image and Video Library

2016-02-04

Ground testing for the first confocal Light Microscopy Microscope (LMM) Experiment. Procter and Gamble is working with NASA Glenn scientists to prepare for a study that examines product stabilizers in a microgravity environment. The particles in the tube glow orange because they have been fluorescently tagged with a dye that reacts to green laser lights to allow construction of a 3D image point by point. The experiment, which will be sent to the ISS later this year, will help P&G develop improved product stabilizers to extend shelf life and develop more environmentally friendly packaging.

The Potential Protective Effects of 2-aminoethyl Diphenylborinate against Inner Ear Acoustic Trauma: Experimental Study Using Transmission and Scanning Electron Microscopy.

PubMed

Kaymakçı, Mustafa; Acar, Mustafa; Burukoglu, Dilek; Kutlu, Hatice Mehtap; Shojaolsadati, Paria; Cingi, Cemal; Bayar Muluk, Nuray

2015-04-01

In this prospective experimental study, we investigated the preventive effects of 2-aminoethyl diphenylborinate (2-APB) in rats exposed to acoustic trauma (AT). Light microscopic, transmission electron microscopic (TEM), and scanning electron microscopic (SEM) examinations were performed. Eighteen healthy Wistar albino rats were divided into the following three groups: groups 1 (control), 2 (AT), and 3 (AT+APB). The rats in groups 2 and 3 were exposed to AT; in group 3 rats, 2-APB at 2 mg/kg was also administered, initially transperitoneally, after 10 min. During the light microscopic, TEM, and SEM examinations, the structures of the cochlear hair cells, stereocilia, and Deiter's cells were normal in the control group. In the AT group, the organ of Corti and proximate structures were damaged according to the light microscopic examination. During the TEM examination, intense cellular damage and stereocilia loss were detected, while during the SEM examination, extensive damage and stereocilia loss were observed. Decreased damage with preserved cochlear structure was detected during the light microscopic examination in the AT+APB group than in the AT group. During the TEM and SEM examinations, although stereocilia loss occurred in the AT+APB group, near-normal cell, cilia, and tectorial membrane structures were also observed in the AT+APB group compared with the AT group. 2-APB may have protective effects against AT damage of the cochlea. The main mechanism underlying this effect is the inhibition of the vasoconstriction of the cochlear spiral modiolar artery, thereby improving cochlear blood flow. We conclude that 2-APB may also be effective if used immediately following AT.

Laser speckle contrast imaging using light field microscope approach

NASA Astrophysics Data System (ADS)

Ma, Xiaohui; Wang, Anting; Ma, Fenghua; Wang, Zi; Ming, Hai

2018-01-01

In this paper, a laser speckle contrast imaging (LSCI) system using light field (LF) microscope approach is proposed. As far as we known, it is first time to combine LSCI with LF. To verify this idea, a prototype consists of a modified LF microscope imaging system and an experimental device was built. A commercially used Lytro camera was modified for microscope imaging. Hollow glass tubes with different depth fixed in glass dish were used to simulate the vessels in brain and test the performance of the system. Compared with conventional LSCI, three new functions can be realized by using our system, which include refocusing, extending the depth of field (DOF) and gathering 3D information. Experiments show that the principle is feasible and the proposed system works well.

A multi-modal stereo microscope based on a spatial light modulator.

PubMed

Lee, M P; Gibson, G M; Bowman, R; Bernet, S; Ritsch-Marte, M; Phillips, D B; Padgett, M J

2013-07-15

Spatial Light Modulators (SLMs) can emulate the classic microscopy techniques, including differential interference (DIC) contrast and (spiral) phase contrast. Their programmability entails the benefit of flexibility or the option to multiplex images, for single-shot quantitative imaging or for simultaneous multi-plane imaging (depth-of-field multiplexing). We report the development of a microscope sharing many of the previously demonstrated capabilities, within a holographic implementation of a stereo microscope. Furthermore, we use the SLM to combine stereo microscopy with a refocusing filter and with a darkfield filter. The instrument is built around a custom inverted microscope and equipped with an SLM which gives various imaging modes laterally displaced on the same camera chip. In addition, there is a wide angle camera for visualisation of a larger region of the sample.

Complex refractive index of starch acetate used as a biodegradable pigment and filler of paper

NASA Astrophysics Data System (ADS)

Karvinen, Petri; Oksman, Antti; Silvennoinen, Raimo; Mikkonen, Hannu

2007-05-01

Complex refractive index of strongly depolarizing starch acetate is investigated as a function of bulk package density, which is compulsory parameter in analysis of light scattering from nanoscale starch acetate pigments and fillers. The measurements were made using a laser-goniometer and spectrophotometer to gain data for refractive index analysis according to the Brewster's law and Fresnel equations. The real part of refractive index was verified by microscopic immersion method.

Nerves and Tissue Repair.

DTIC Science & Technology

1992-05-21

complete dependence on nerves. Organ culture of sciatic nerves, combined with an assay for axolotl transferrin developed earlier, allows quantitative study...axonal release of various unknown proteins. Combining this approach with the ELISA for quantitative measurement of axolotl transferrin developed with...light microscope autoradiographic analysis following binding of radiolabelled Tf. Studies of Tf synthesis will employ cDNA probes for axolotl Tf mRNA

Lensfree microscopy on a cellphone

PubMed Central

Tseng, Derek; Mudanyali, Onur; Oztoprak, Cetin; Isikman, Serhan O.; Sencan, Ikbal; Yaglidere, Oguzhan; Ozcan, Aydogan

2010-01-01

We demonstrate lensfree digital microscopy on a cellphone. This compact and light-weight holographic microscope installed on a cellphone does not utilize any lenses, lasers or other bulky optical components and it may offer a cost-effective tool for telemedicine applications to address various global health challenges. Weighing ~38 grams (<1.4 ounces), this lensfree imaging platform can be mechanically attached to the camera unit of a cellphone where the samples are loaded from the side, and are vertically illuminated by a simple light-emitting diode (LED). This incoherent LED light is then scattered from each micro-object to coherently interfere with the background light, creating the lensfree hologram of each object on the detector array of the cellphone. These holographic signatures captured by the cellphone permit reconstruction of microscopic images of the objects through rapid digital processing. We report the performance of this lensfree cellphone microscope by imaging various sized micro-particles, as well as red blood cells, white blood cells, platelets and a waterborne parasite (Giardia lamblia). PMID:20445943

Simple and cost-effective hardware and software for functional brain mapping using intrinsic optical signal imaging.

PubMed

Harrison, Thomas C; Sigler, Albrecht; Murphy, Timothy H

2009-09-15

We describe a simple and low-cost system for intrinsic optical signal (IOS) imaging using stable LED light sources, basic microscopes, and commonly available CCD cameras. IOS imaging measures activity-dependent changes in the light reflectance of brain tissue, and can be performed with a minimum of specialized equipment. Our system uses LED ring lights that can be mounted on standard microscope objectives or video lenses to provide a homogeneous and stable light source, with less than 0.003% fluctuation across images averaged from 40 trials. We describe the equipment and surgical techniques necessary for both acute and chronic mouse preparations, and provide software that can create maps of sensory representations from images captured by inexpensive 8-bit cameras or by 12-bit cameras. The IOS imaging system can be adapted to commercial upright microscopes or custom macroscopes, eliminating the need for dedicated equipment or complex optical paths. This method can be combined with parallel high resolution imaging techniques such as two-photon microscopy.

Digital photography for the light microscope: results with a gated, video-rate CCD camera and NIH-image software.

PubMed

Shaw, S L; Salmon, E D; Quatrano, R S

1995-12-01

In this report, we describe a relatively inexpensive method for acquiring, storing and processing light microscope images that combines the advantages of video technology with the powerful medium now termed digital photography. Digital photography refers to the recording of images as digital files that are stored, manipulated and displayed using a computer. This report details the use of a gated video-rate charge-coupled device (CCD) camera and a frame grabber board for capturing 256 gray-level digital images from the light microscope. This camera gives high-resolution bright-field, phase contrast and differential interference contrast (DIC) images but, also, with gated on-chip integration, has the capability to record low-light level fluorescent images. The basic components of the digital photography system are described, and examples are presented of fluorescence and bright-field micrographs. Digital processing of images to remove noise, to enhance contrast and to prepare figures for printing is discussed.

Dental microwear textures: reconstructing diets of fossil mammals

NASA Astrophysics Data System (ADS)

DeSantis, Larisa R. G.

2016-06-01

Dietary information of fossil mammals can be revealed via the analysis of tooth morphology, tooth wear, tooth geochemistry, and the microscopic wear patterns on tooth surfaces resulting from food processing. Although dental microwear has long been used by anthropologists and paleontologists to clarify diets in a diversity of mammals, until recently these methods focused on the counting of wear features (e.g., pits and scratches) from two-dimensional surfaces (typically via scanning electron microscopes or low-magnification light microscopes). The analysis of dental microwear textures can instead reveal dietary information in a broad range of herbivorous, omnivorous, and carnivorous mammals by characterizing microscopic tooth surfaces in three-dimensions, without the counting of individual surface features. To date, dental microwear textures in ungulates, xenarthrans, marsupials, carnivorans, and primates (including humans and their ancestors) are correlated with known dietary behavior in extant taxa and reconstruct ancient diets in a diversity of prehistoric mammals. For example, tough versus hard object feeding can be characterized across disparate phylogenetic groups and can distinguish grazers, folivorous, and flesh consumers (tougher food consumers) from woody browsers, frugivores, and bone consumers (harder object feeders). This paper reviews how dental microwear textures can be useful to reconstructing diets in a broad array of living and extinct mammals, with commentary on areas of future research.

Setup and use of a two-laser multiphoton microscope for multichannel intravital fluorescence imaging

PubMed Central

Entenberg, David; Wyckoff, Jeffrey; Gligorijevic, Bojana; Roussos, Evanthia T; Verkhusha, Vladislav V; Pollard, Jeffrey W; Condeelis, John

2014-01-01

Characterizing biological mechanisms dependent upon the interaction of many cell types in vivo requires both multiphoton microscope systems capable of expanding the number and types of fluorophores that can be imaged simultaneously while removing the wavelength and tunability restrictions of existing systems, and enhanced software for extracting critical cellular parameters from voluminous 4D data sets. We present a procedure for constructing a two-laser multiphoton microscope that extends the wavelength range of excitation light, expands the number of simultaneously usable fluorophores and markedly increases signal to noise via ‘over-clocking’ of detection. We also utilize a custom-written software plug-in that simplifies the quantitative tracking and analysis of 4D intravital image data. We begin by describing the optics, hardware, electronics and software required, and finally the use of the plug-in for analysis. We demonstrate the use of the setup and plug-in by presenting data collected via intravital imaging of a mouse model of breast cancer. The procedure may be completed in ~24 h. PMID:21959234

The Pathologist 2.0: An Update on Digital Pathology in Veterinary Medicine.

PubMed

Bertram, Christof A; Klopfleisch, Robert

2017-09-01

Using light microscopy to describe the microarchitecture of normal and diseased tissues has changed very little since the middle of the 19th century. While the premise of histologic analysis remains intact, our relationship with the microscope is changing dramatically. Digital pathology offers new forms of visualization, and delivery of images is facilitated in unprecedented ways. This new technology can untether us entirely from our light microscopes, with many pathologists already performing their jobs using virtual microscopy. Several veterinary colleges have integrated virtual microscopy in their curriculum, and some diagnostic histopathology labs are switching to virtual microscopy as their main tool for the assessment of histologic specimens. Considering recent technical advancements of slide scanner and viewing software, digital pathology should now be considered a serious alternative to traditional light microscopy. This review therefore intends to give an overview of the current digital pathology technologies and their potential in all fields of veterinary pathology (ie, research, diagnostic service, and education). A future integration of digital pathology in the veterinary pathologist's workflow seems to be inevitable, and therefore it is proposed that trainees should be taught in digital pathology to keep up with the unavoidable digitization of the profession.

Microscopic and histochemical manifestations of hyaline cartilage dynamics.

PubMed

Malinin, G I; Malinin, T I

1999-01-01

Structure and function of hyaline cartilages has been the focus of many correlative studies for over a hundred years. Much of what is known regarding dynamics and function of cartilage constituents has been derived or inferred from biochemical and electron microscopic investigations. Here we show that in conjunction with ultrastructural, and high-magnification transmission light and polarization microscopy, the well-developed histochemical methods are indispensable for the analysis of cartilage dynamics. Microscopically demonstrable aspects of cartilage dynamics include, but are not limited to, formation of the intracellular liquid crystals, phase transitions of the extracellular matrix and tubular connections between chondrocytes. The role of the interchondrocytic liquid crystals is considered in terms of the tensegrity hypothesis and non-apoptotic cell death. Phase transitions of the extracellular matrix are discussed in terms of self-alignment of chondrons, matrix guidance pathways and cartilage growth in the absence of mitosis. The possible role of nonenzymatic glycation reactions in cartilage dynamics is also reviewed.

Development of an environmental high-voltage electron microscope for reaction science.

PubMed

Tanaka, Nobuo; Usukura, Jiro; Kusunoki, Michiko; Saito, Yahachi; Sasaki, Katuhiro; Tanji, Takayoshi; Muto, Shunsuke; Arai, Shigeo

2013-02-01

Environmental transmission electron microscopy and ultra-high resolution electron microscopic observation using aberration correctors have recently emerged as topics of great interest. The former method is an extension of the so-called in situ electron microscopy that has been performed since the 1970s. Current research in this area has been focusing on dynamic observation with atomic resolution under gaseous atmospheres and in liquids. Since 2007, Nagoya University has been developing a new 1-MV high voltage (scanning) transmission electron microscope that can be used to observe nanomaterials under conditions that include the presence of gases, liquids and illuminating lights, and it can be also used to perform mechanical operations to nanometre-sized areas as well as electron tomography and elemental analysis by electron energy loss spectroscopy. The new instrument has been used to image and analyse various types of samples including biological ones.

Fast parallel 3D profilometer with DMD technology

NASA Astrophysics Data System (ADS)

Hou, Wenmei; Zhang, Yunbo

2011-12-01

Confocal microscope has been a powerful tool for three-dimensional profile analysis. Single mode confocal microscope is limited by scanning speed. This paper presents a 3D profilometer prototype of parallel confocal microscope based on DMD (Digital Micromirror Device). In this system the DMD takes the place of Nipkow Disk which is a classical parallel scanning scheme to realize parallel lateral scanning technique. Operated with certain pattern, the DMD generates a virtual pinholes array which separates the light into multi-beams. The key parameters that affect the measurement (pinhole size and the lateral scanning distance) can be configured conveniently by different patterns sent to DMD chip. To avoid disturbance between two virtual pinholes working at the same time, a scanning strategy is adopted. Depth response curve both axial and abaxial were extract. Measurement experiments have been carried out on silicon structured sample, and axial resolution of 55nm is achieved.

Microstructure and Texture Evolutions of Biomedical Ti-13Nb-13Zr Alloy Processed by Hydrostatic Extrusion

NASA Astrophysics Data System (ADS)

Ozaltin, K.; Panigrahi, A.; Chrominski, W.; Bulutsuz, A. G.; Kulczyk, M.; Zehetbauer, M. J.; Lewandowska, M.

2017-11-01

A biomedical β-type Ti-13Nb-13Zr (TNZ) (wt pct) ternary alloy was subjected to severe plastic deformation by means of hydrostatic extrusion (HE) at room temperature without intermediate annealing. Its effect on microstructure, mechanical properties, phase transformations, and texture was investigated by light and electron microscopy, mechanical tests (Vickers microhardness and tensile tests), and XRD analysis. Microstructural investigations by light microscope and transmission electron microscope showed that, after HE, significant grain refinement took place, also reaching high dislocation densities. Increases in strength up to 50 pct occurred, although the elongation to fracture left after HE was almost 9 pct. Furthermore, Young's modulus of HE-processed samples showed slightly lower values than the initial state due to texture. Such mechanical properties combined with lower Young's modulus are favorable for medical applications. Phase transformation analyses demonstrated that both initial and extruded samples consist of α' and β phases but that the phase fraction of α' was slightly higher after two stages of HE.

Accessible microscopy workstation for students and scientists with mobility impairments.

PubMed

Duerstock, Bradley S

2006-01-01

An integrated accessible microscopy workstation was designed and developed to allow persons with mobility impairments to control all aspects of light microscopy with minimal human assistance. This system, named AccessScope, is capable of performing brightfield and fluorescence microscopy, image analysis, and tissue morphometry requisite for undergraduate science courses to graduate-level research. An accessible microscope is necessary for students and scientists with mobility impairments to be able to use a microscope independently to better understand microscopical imaging concepts and cell biology. This knowledge is not always apparent by simply viewing a catalog of histological images. The ability to operate a microscope independently eliminates the need to hire an assistant or rely on a classmate and permits one to take practical laboratory examinations by oneself. Independent microscope handling is also crucial for graduate students and scientists with disabilities to perform scientific research. By making a personal computer as the user interface for controlling AccessScope functions, different upper limb mobility impairments could be accommodated by using various computer input devices and assistive technology software. Participants with a range of upper limb mobility impairments evaluated the prototype microscopy workstation. They were able to control all microscopy functions including loading different slides without assistance.

Fluorescence microscope (Cyscope) for malaria diagnosis in pregnant women in Medani Hospital, Sudan.

PubMed

Hassan, Saad El-Din H; Haggaz, Abd Elrahium D; Mohammed-Elhassan, Ehab B; Malik, Elfatih M; Adam, Ishag

2011-09-24

Accuracy of diagnosis is the core for malaria control. Although microscopy is the gold standard in malaria diagnosis, its reliability is largely dependent on user skill. We compared performance of Cyscope fluorescence microscope with the Giemsa stained light microscopy for the diagnosis of malaria among pregnant women at Medani Hospital in Central Sudan. The area is characterized by unstable malaria transmission. Socio-demographic characteristics and obstetrics history were gathered using pre-tested questionnaires. Blood samples were collected from febrile pregnant women who were referred as malaria case following initial diagnosis by general microscopist. During the study period 128 febrile pregnant women presented at the hospital. Among them, Plasmodium falciparum malaria was detected in 82 (64.1%) and 80 (62.5%) by the Giemsa-stained light microscopy and the Cyscope fluorescence microscope, respectively. The sensitivity of the Cyscope fluorescence microscope was 97.6% (95% CI: 92.2%-99.6%). Out of 46 which were negative by Giemsa-stained light microscopy, 5 were positive by the Cyscope fluorescence microscope. This is translated in specificity of 89.1% (95% CI: 77.5%-95.9%). The positive and negative predictive value of Cyscope fluorescence microscope was 94.1% (95% CI: 87.4% -97.8%) and 95.3% (95% CI: 85.4% - 99.2%), respectively. This study has shown that Cyscope fluorescence microscope is a reliable diagnostic, sensitive and specific in diagnosing P. falciparum malaria among pregnant women in this setting. Further studies are needed to determine effectiveness in diagnosing other Plasmodium species and to compare it with other diagnostic tools e.g. rapid diagnostic tests and PCR.

[THE CHARACTERISTICS OF MORPHOLOGY OF BIOFILM OF PERIODONTIUM UNDER INFLAMMATORY DISEASES OF GUMS (CHRONIC CATARRHAL GINGIVITIS, CHRONIC PERIODONTITIS, CANDIDA-ASSOCIATED PERIODONTITIS) ACCORDING RESULTS OF ELECTRONIC MICROSCOPY].

PubMed

Ippolitov, E V; Didenko, L V; Tzarev, V N

2015-12-01

The study was carried out to analyze morphology of biofilm of periodontium and to develop electronic microscopic criteria of differentiated diagnostic of inflammatory diseases of gums. The scanning electronic microscopy was applied to analyze samples of bioflm of periodont from 70 patients. Including ten patients with every nosologic form of groups with chronic catarrhal periodontitis. of light, mean and severe degree, chronic catarrhal gingivitis, Candida-associated paroperiodontitis and 20 healthy persons with intact periodontium. The analysis was implemented using dual-beam scanning electronic microscope Quanta 200 3D (FEI company, USA) and walk-through electronic micJEM 100B (JEOL, Japan). To detect marker DNA of periodont pathogenic bacteria in analyzed samples the kit of reagentsfor polymerase chain reaction "MultiDent-5" ("GenLab", Russia). The scanning electronic microscopy in combination with transmission electronic microscopy and polymerase chain reaction permits analyzing structure, composition and degree of development of biofilm of periodontium and to apply differentiated diagnostic of different nosologic forms of inflammatory diseases of periodontium, including light form of chronic periodontitis and gingivitis. The electronic microscopical indications of diseases ofperiodontium of inflammatory character are established: catarrhal gingivitis, (coccal morphological alternate), chronic periodontitis (bacillary morphological alternate), Candida-associated periodontitis (Candida morphological alternate of biofilm ofperiodontium).

Real-time restoration of white-light confocal microscope optical sections

PubMed Central

Balasubramanian, Madhusudhanan; Iyengar, S. Sitharama; Beuerman, Roger W.; Reynaud, Juan; Wolenski, Peter

2009-01-01

Confocal microscopes (CM) are routinely used for building 3-D images of microscopic structures. Nonideal imaging conditions in a white-light CM introduce additive noise and blur. The optical section images need to be restored prior to quantitative analysis. We present an adaptive noise filtering technique using Karhunen–Loéve expansion (KLE) by the method of snapshots and a ringing metric to quantify the ringing artifacts introduced in the images restored at various iterations of iterative Lucy–Richardson deconvolution algorithm. The KLE provides a set of basis functions that comprise the optimal linear basis for an ensemble of empirical observations. We show that most of the noise in the scene can be removed by reconstructing the images using the KLE basis vector with the largest eigenvalue. The prefiltering scheme presented is faster and does not require prior knowledge about image noise. Optical sections processed using the KLE prefilter can be restored using a simple inverse restoration algorithm; thus, the methodology is suitable for real-time image restoration applications. The KLE image prefilter outperforms the temporal-average prefilter in restoring CM optical sections. The ringing metric developed uses simple binary morphological operations to quantify the ringing artifacts and confirms with the visual observation of ringing artifacts in the restored images. PMID:20186290

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooke, Gary A.; Pestovich, John A.; Huber, Heinz J.

This report presents the results for solid phase characterization (SPC) of solid samples removed from tank 241-C-108 (C-108) on August 12-13,2012, using the off-riser sampler. Samples were received at the 222-S Laboratory on August 13 and were described and photographed. The SPC analyses that were performed include scanning electron microscopy (SEM) using the ASPEX(R)l scanning electron microscope, X-ray diffraction (XRD) using the Rigaku(R) 2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon(R) 3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information. Gary A. Cooke conducted themore » SEM analysis, John A. Pestovich performed the XRD analysis, and Dr. Heinz J. Huber performed the PLM examination. The results of these analyses are presented here.« less

Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy

PubMed Central

Brooker, Gary; Siegel, Nisan; Wang, Victor; Rosen, Joseph

2011-01-01

Fresnel Incoherent Correlation Holography (FINCH) enables holograms and 3D images to be created from incoherent light with just a camera and spatial light modulator (SLM). We previously described its application to microscopic incoherent fluorescence wherein one complex hologram contains all the 3D information in the microscope field, obviating the need for scanning or serial sectioning. We now report experiments which have led to the optimal optical, electro-optic, and computational conditions necessary to produce holograms which yield high quality 3D images from fluorescent microscopic specimens. An important improvement from our previous FINCH configurations capitalizes on the polarization sensitivity of the SLM so that the same SLM pixels which create the spherical wave simulating the microscope tube lens, also pass the plane waves from the infinity corrected microscope objective, so that interference between the two wave types at the camera creates a hologram. This advance dramatically improves the resolution of the FINCH system. Results from imaging a fluorescent USAF pattern and a pollen grain slide reveal resolution which approaches the Rayleigh limit by this simple method for 3D fluorescent microscopic imaging. PMID:21445140

A Low-Cost Digital Microscope with Real-Time Fluorescent Imaging Capability.

PubMed

Hasan, Md Mehedi; Alam, Mohammad Wajih; Wahid, Khan A; Miah, Sayem; Lukong, Kiven Erique

2016-01-01

This paper describes the development of a prototype of a low-cost digital fluorescent microscope built from commercial off-the-shelf (COTS) components. The prototype was tested to detect malignant tumor cells taken from a living organism in a preclinical setting. This experiment was accomplished by using Alexa Fluor 488 conjugate dye attached to the cancer cells. Our prototype utilizes a torch along with an excitation filter as a light source for fluorophore excitation, a dichroic mirror to reflect the excitation and pass the emitted green light from the sample under test and a barrier filter to permit only appropriate wavelength. The system is designed out of a microscope using its optical zooming property and an assembly of exciter filter, dichroic mirror and transmitter filter. The microscope is connected to a computer or laptop through universal serial bus (USB) that allows real-time transmission of captured florescence images; this also offers real-time control of the microscope. The designed system has comparable features of high-end commercial fluorescent microscopes while reducing cost, power, weight and size.

A Low-Cost Digital Microscope with Real-Time Fluorescent Imaging Capability

PubMed Central

Hasan, Md. Mehedi; Wahid, Khan A.; Miah, Sayem; Lukong, Kiven Erique

2016-01-01

This paper describes the development of a prototype of a low-cost digital fluorescent microscope built from commercial off-the-shelf (COTS) components. The prototype was tested to detect malignant tumor cells taken from a living organism in a preclinical setting. This experiment was accomplished by using Alexa Fluor 488 conjugate dye attached to the cancer cells. Our prototype utilizes a torch along with an excitation filter as a light source for fluorophore excitation, a dichroic mirror to reflect the excitation and pass the emitted green light from the sample under test and a barrier filter to permit only appropriate wavelength. The system is designed out of a microscope using its optical zooming property and an assembly of exciter filter, dichroic mirror and transmitter filter. The microscope is connected to a computer or laptop through universal serial bus (USB) that allows real-time transmission of captured florescence images; this also offers real-time control of the microscope. The designed system has comparable features of high-end commercial fluorescent microscopes while reducing cost, power, weight and size. PMID:27977709

Neonatal lines in the enamel of primary teeth--a morphological and scanning electron microscopic investigation.

PubMed

Sabel, Nina; Johansson, Carina; Kühnisch, Jan; Robertson, Agneta; Steiniger, Frank; Norén, Jörgen G; Klingberg, Gunilla; Nietzsche, Sandor

2008-10-01

The neonatal line (NNL) is in principle found in all primary teeth and the line represents the time of birth. Earlier findings of the appearance of the NNL in light microscope and in microradiographs have shown not only changes in the prism direction of the enamel, but that the NNL has a hypomineralized character. The neonatal line was analyzed in un-decalcified sections of primary lower and central incisors, collected from individuals of different ages utilizing polarized light microscopy, microradiography, scanning electron microscopy (SEM) and X-ray analysis (XRMA). In polarized light the NNL appeared to have a more porous structure than the enamel in general. The appearance of the NNL as a dark line in microradiographs is interpreted as the NNL being less mineralized than neighbouring enamel. Analysis with ImageJ visualized the reduction of the amount of grey value, indicating that the NNL is less mineralized. Analysis of the NNL in SEM showed a reduction of the diameter of enamel prisms, the more narrow diameters continued through the postnatal enamel. A change of the growth direction of the prisms was also observed at the NNL. In a three-dimensional image the NNL appeared as a grove, however, in non-etched enamel no grove was seen. The elemental analyses with XRMA showed no marked changes in the content of C, Ca, P, N, O or S in the area around the NNL. The NNL is an optical phenomenon due to alterations in height, and degree of mineralization of the enamel prisms.

The HVAC Challenges of Upgrading an Old Lab for High-end Light Microscopes

PubMed Central

Richard, R.; Martone, P.; Callahan, L.M.

2014-01-01

The University of Rochester Medical Center forms the centerpiece of the University of Rochester's health research, teaching, patient care, and community outreach missions. Within this large facility of over 5 million square feet, demolition and remodeling of existing spaces is a constant activity. With more than $145 million in federal research funding, lab space is frequently repurposed and renovated to support this work. The URMC Medical Center Facilities Organization supporting small to medium space renovations is constantly challenged and constrained by the existing mechanical infrastructure and budgets to deliver a renovated space that functions within the equipment environmental parameters. One recent project, sponsored by the URMC Shared Resources Laboratory, demonstrates these points. The URMC Light Microscopy Shared Resource Laboratory requested renovation of a 121 sq. ft. room in a 40 year old building which would enable placement of a laser capture microdissection microscope and a Pascal 5 laser scanning confocal microscope with the instruments separated by a blackout curtain. This poster discusses the engineering approach implemented to bring an older lab into the environmental specifications needed for the proper operation of the high-end light microscopes.

From Animaculum to single molecules: 300 years of the light microscope.

PubMed

Wollman, Adam J M; Nudd, Richard; Hedlund, Erik G; Leake, Mark C

2015-04-01

Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632-1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term 'biologists'). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739 Phil. Trans. 41, 503-519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800 The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition of Open Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the last ca 300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants.

Adaptive optics plug-and-play setup for high-resolution microscopes with multi-actuator adaptive lens

NASA Astrophysics Data System (ADS)

Quintavalla, M.; Pozzi, P.; Verhaegen, Michelle; Bijlsma, Hielke; Verstraete, Hans; Bonora, S.

2018-02-01

Adaptive Optics (AO) has revealed as a very promising technique for high-resolution microscopy, where the presence of optical aberrations can easily compromise the image quality. Typical AO systems however, are almost impossible to implement on commercial microscopes. We propose a simple approach by using a Multi-actuator Adaptive Lens (MAL) that can be inserted right after the objective and works in conjunction with an image optimization software allowing for a wavefront sensorless correction. We presented the results obtained on several commercial microscopes among which a confocal microscope, a fluorescence microscope, a light sheet microscope and a multiphoton microscope.

Specimen illumination apparatus with optical cavity for dark field illumination

DOEpatents

Pinkel, Daniel; Sudar, Damir; Albertson, Donna

1999-01-01

An illumination apparatus with a specimen slide holder, an illumination source, an optical cavity producing multiple reflection of illumination light to a specimen comprising a first and a second reflective surface arranged to achieve multiple reflections of light to a specimen is provided. The apparatus can further include additional reflective surfaces to achieve the optical cavity, a slide for mounting the specimen, a coverslip which is a reflective component of the optical cavity, one or more prisms for directing light within the optical cavity, antifading solutions for improving the viewing properties of the specimen, an array of materials for analysis, fluorescent components, curved reflective surfaces as components of the optical cavity, specimen detection apparatus, optical detection equipment, computers for analysis of optical images, a plane polarizer, fiberoptics, light transmission apertures, microscopic components, lenses for viewing the specimen, and upper and lower mirrors above and below the specimen slide as components of the optical cavity. Methods of using the apparatus are also provided.

Scanning optical microscope with long working distance objective

DOEpatents

Cloutier, Sylvain G.

2010-10-19

A scanning optical microscope, including: a light source to generate a beam of probe light; collimation optics to substantially collimate the probe beam; a probe-result beamsplitter; a long working-distance, infinity-corrected objective; scanning means to scan a beam spot of the focused probe beam on or within a sample; relay optics; and a detector. The collimation optics are disposed in the probe beam. The probe-result beamsplitter is arranged in the optical paths of the probe beam and the resultant light from the sample. The beamsplitter reflects the probe beam into the objective and transmits resultant light. The long working-distance, infinity-corrected objective is also arranged in the optical paths of the probe beam and the resultant light. It focuses the reflected probe beam onto the sample, and collects and substantially collimates the resultant light. The relay optics are arranged to relay the transmitted resultant light from the beamsplitter to the detector.

Transmission electron microscope sample holder with optical features

DOEpatents

Milas, Mirko [Port Jefferson, NY; Zhu, Yimei [Stony Brook, NY; Rameau, Jonathan David [Coram, NY

2012-03-27

A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

Microcircuit testing and fabrication, using scanning electron microscopes

NASA Technical Reports Server (NTRS)

Nicolas, D. P.

1975-01-01

Scanning electron microscopes are used to determine both user-induced damages and manufacturing defects subtle enough to be missed by conventional light microscopy. Method offers greater depth of field and increased working distances.

ultraLM and miniLM: Locator tools for smart tracking of fluorescent cells in correlative light and electron microscopy.

PubMed

Brama, Elisabeth; Peddie, Christopher J; Wilkes, Gary; Gu, Yan; Collinson, Lucy M; Jones, Martin L

2016-12-13

In-resin fluorescence (IRF) protocols preserve fluorescent proteins in resin-embedded cells and tissues for correlative light and electron microscopy, aiding interpretation of macromolecular function within the complex cellular landscape. Dual-contrast IRF samples can be imaged in separate fluorescence and electron microscopes, or in dual-modality integrated microscopes for high resolution correlation of fluorophore to organelle. IRF samples also offer a unique opportunity to automate correlative imaging workflows. Here we present two new locator tools for finding and following fluorescent cells in IRF blocks, enabling future automation of correlative imaging. The ultraLM is a fluorescence microscope that integrates with an ultramicrotome, which enables 'smart collection' of ultrathin sections containing fluorescent cells or tissues for subsequent transmission electron microscopy or array tomography. The miniLM is a fluorescence microscope that integrates with serial block face scanning electron microscopes, which enables 'smart tracking' of fluorescent structures during automated serial electron image acquisition from large cell and tissue volumes.

Atomic force microscopic imaging of Acanthamoeba castellanii and Balamuthia mandrillaris trophozoites and cysts.

PubMed

Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Ateeq, Muhammad; Raza Shah, Muhammad; Kulsoom, Huma; Khan, Naveed Ahmed

2015-01-01

Light microscopy and electron microscopy have been successfully used in the study of microbes, as well as free-living protists. Unlike light microscopy, which enables us to observe living organisms or the electron microscope which provides a two-dimensional image, atomic force microscopy provides a three-dimensional surface profile. Here, we observed two free-living amoebae, Acanthamoeba castellanii and Balamuthia mandrillaris under the phase contrast inverted microscope, transmission electron microscope and atomic force microscope. Although light microscopy was of lower magnification, it revealed functional biology of live amoebae such as motility and osmoregulation using contractile vacuoles of the trophozoite stage, but it is of limited value in defining the cyst stage. In contrast, transmission electron microscopy showed significantly greater magnification and resolution to reveal the ultra-structural features of trophozoites and cysts including intracellular organelles and cyst wall characteristics but it only produced a snapshot in time of a dead amoeba cell. Atomic force microscopy produced three-dimensional images providing detailed topographic description of shape and surface, phase imaging measuring boundary stiffness, and amplitude measurements including width, height and length of A. castellanii and B. mandrillaris trophozoites and cysts. These results demonstrate the importance of the application of various microscopic methods in the biological and structural characterization of the whole cell, ultra-structural features, as well as surface components and cytoskeleton of protist pathogens. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

Thin laser light sheet microscope for microbial oceanography

NASA Astrophysics Data System (ADS)

Fuchs, Eran; Jaffe, Jules S.; Long, Richard A.; Azam, Farooq

2002-01-01

Despite a growing need, oceanographers are limited by existing technological constrains and are unable to observe aquatic microbes in their natural setting. In order to provide a simple and easy to implement solution for such studies, a new Thin Light Sheet Microscope (TLSM) has been developed. The TLSM utilizes a well-defined sheet of laser light, which has a narrow (23 micron) axial dimension over a 1 mm x 1 mm field of view. This light sheet is positioned precisely within the depth of field of the microscope’s objective lens. The technique thus utilizes conventional microscope optics but replaces the illumination system. The advantages of the TLSM are two-fold: First, it concentrates light only where excitation is needed, thus maximizing the efficiency of the illumination source. Secondly, the TLSM maximizes image sharpness while at the same time minimizing the level of background noise. Particles that are not located within the objective's depth of field are not illuminated and therefore do not contribute to an out-of-focus image. Images from a prototype system that used SYBR Green I fluorescence stain in order to localize single bacteria are reported. The bacteria were in a relatively large and undisturbed volume of 4ml, which contained natural seawater. The TLSM can be used for fresh water studies of bacteria with no modification. The microscope permits the observation of interactions at the microscale and has potential to yield insights into how microbes structure pelagic ecosystems.

Identification and quantitative evaluation of the fiber structure in the pathological tissue using Mueller matrix microscope

NASA Astrophysics Data System (ADS)

Zhou, Jialing; He, Honghui; Wang, Ye; Ma, Hui

2017-02-01

Fiber structure changes in the various pathological processes, such as the increase of fibrosis in liver diseases, the derangement of fiber in cervical cancer and so on. Currently, clinical pathologic diagnosis is regarded as the golden criterion, but different doctors with discrepancy in knowledge and experience may obtain different conclusions. Up to a point, quantitative evaluation of the fiber structure in the pathological tissue can be of great service to quantitative diagnosis. Mueller matrix measurement is capable of probing comprehensive microstructural information of samples and different wavelength of lights can provide more information. In this paper, we use a Mueller matrix microscope with light sources in six different wavelength. We use unstained, dewaxing liver tissue slices in four stages and the pathological biopsy of the filtration channels from rabbit eyes as samples. We apply the Mueller matrix polar decomposition (MMPD) parameter δ which corresponds to retardance to liver slices. The mean value of abnormal region get bigger when the level of fibrosis get higher and light in short wavelength is more sensitive to the microstructure of fiber. On the other hand, we use the Mueller matrix transformation (MMT) parameter Φ which is associated to the angel of fast axis in the analysis of the slices of the filtration channels from rabbit eyes. The value of kurtosis and the value of skewness shows big difference between new born region and normal region and can reveal the arrangement of fiber. These results indicate that the Mueller matrix microscope has great potential in auxiliary diagnosis.

Analysis of DNA methylation in FFPE tissues using the MethyLight technology.

PubMed

Dallol, Ashraf; Al-Ali, Waleed; Al-Shaibani, Amina; Al-Mulla, Fahd

2011-01-01

Novel biomarkers are sought after by mining DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissues. Such tissues offer the great advantage of often having complete clinical data (including survival), as well as the tissues are amenable for laser microdissection targeting specific tissue areas. Downstream analysis of such DNA includes mutational screens and methylation profiling. Screening for mutations by sequencing requires a significant amount of DNA for PCR and cycle sequencing. This is self-inhibitory if the gene screened has a large number of exons. Profiling DNA methylation using the MethyLight technology circumvents this problem and allows for the mining of several biomarkers from DNA extracted from a single microscope slide of the tissue of interest. We describe in this chapter a detailed protocol for MethyLight and its use in the determination of CpG Island Methylator Phenotype status in FFPE colorectal cancer samples.

Collaborative study on the effect of grinding on the detection of bones from processed animal proteins in feed by light microscopy.

PubMed

Veys, Pascal; Planchon, Viviane; Colbert, Ruairi; Cruz, Clara; Frick, Geneviève; Ioannou, Ioannis; Marchis, Daniela; Nordkvist, Erik; Paradies-Severin, Inge; Pohto, Arja; Weiss, Roland; Baeten, Vincent; Berben, Gilbert

2017-08-01

Bone fragments are essential structures for the detection of processed animal proteins (PAPs) in feed by light microscopy for official controls according to Annex VI of European Union Regulation EC/152/2009. The preparation of samples submitted for analysis requires a grinding step to make them suitable for microscopic slide preparation and observation. However, there are no technical guidelines set down for this step despite the fact that it can lead to an increase in bone numbers due to fragmentation. This was demonstrated by an in-house study carried out by the Irish National Reference Laboratory (NRL) for animal protein detection. The present collaborative study investigated the possible effects of three different grinding conditions on the final result for a feed adulterated with 0.05 and 0.01% (w/w) of PAP. The microscopic analysis either combined or not with an Alizarin Red staining was carried out by 10 different laboratories. The results demonstrated that although a large variation in the numbers of bone fragments was noted, five of the six different grinding/staining combinations applied at two levels of PAP adulteration did not significantly (at p = 0.05) differ from one another. The only exception occurred when grinding the feed containing 0.05% of PAP with a rotor mill equipped with a 0.5-mm sieve and combined with a staining which resulted in a greater number of bone fragments by forced fragmentation. Overall, the impact of the grinding/staining combinations on the final results was shown to be negligible when considering the regulatory limit of detection (LOD) requirement for the method and the current rules of implementation of the light microscopic method. From a total of 180 analyses carried out on the feed matrix containing 0.05% of PAP no false-negative result was observed, and at a level of 0.01% PAP only 10 false-negative results occurred.

Inverted light-sheet microscope for imaging mouse pre-implantation development.

PubMed

Strnad, Petr; Gunther, Stefan; Reichmann, Judith; Krzic, Uros; Balazs, Balint; de Medeiros, Gustavo; Norlin, Nils; Hiiragi, Takashi; Hufnagel, Lars; Ellenberg, Jan

2016-02-01

Despite its importance for understanding human infertility and congenital diseases, early mammalian development has remained inaccessible to in toto imaging. We developed an inverted light-sheet microscope that enabled us to image mouse embryos from zygote to blastocyst, computationally track all cells and reconstruct a complete lineage tree of mouse pre-implantation development. We used this unique data set to show that the first cell fate specification occurs at the 16-cell stage.

Neuroanatomy from Mesoscopic to Nanoscopic Scales: An Improved Method for the Observation of Semithin Sections by High-Resolution Scanning Electron Microscopy

PubMed Central

Rodríguez, José-Rodrigo; Turégano-López, Marta; DeFelipe, Javier; Merchán-Pérez, Angel

2018-01-01

Semithin sections are commonly used to examine large areas of tissue with an optical microscope, in order to locate and trim the regions that will later be studied with the electron microscope. Ideally, the observation of semithin sections would be from mesoscopic to nanoscopic scales directly, instead of using light microscopy and then electron microscopy (EM). Here we propose a method that makes it possible to obtain high-resolution scanning EM images of large areas of the brain in the millimeter to nanometer range. Since our method is compatible with light microscopy, it is also feasible to generate hybrid light and electron microscopic maps. Additionally, the same tissue blocks that have been used to obtain semithin sections can later be used, if necessary, for transmission EM, or for focused ion beam milling and scanning electron microscopy (FIB-SEM). PMID:29568263

Neuroanatomy from Mesoscopic to Nanoscopic Scales: An Improved Method for the Observation of Semithin Sections by High-Resolution Scanning Electron Microscopy.

PubMed

Rodríguez, José-Rodrigo; Turégano-López, Marta; DeFelipe, Javier; Merchán-Pérez, Angel

2018-01-01

Semithin sections are commonly used to examine large areas of tissue with an optical microscope, in order to locate and trim the regions that will later be studied with the electron microscope. Ideally, the observation of semithin sections would be from mesoscopic to nanoscopic scales directly, instead of using light microscopy and then electron microscopy (EM). Here we propose a method that makes it possible to obtain high-resolution scanning EM images of large areas of the brain in the millimeter to nanometer range. Since our method is compatible with light microscopy, it is also feasible to generate hybrid light and electron microscopic maps. Additionally, the same tissue blocks that have been used to obtain semithin sections can later be used, if necessary, for transmission EM, or for focused ion beam milling and scanning electron microscopy (FIB-SEM).

A Simple low-cost device enables four epi-illumination techniques on standard light microscopes.

PubMed

Ishmukhametov, Robert R; Russell, Aidan N; Wheeler, Richard J; Nord, Ashley L; Berry, Richard M

2016-02-08

Back-scattering darkfield (BSDF), epi-fluorescence (EF), interference reflection contrast (IRC), and darkfield surface reflection (DFSR) are advanced but expensive light microscopy techniques with limited availability. Here we show a simple optical design that combines these four techniques in a simple low-cost miniature epi-illuminator, which inserts into the differential interference-contrast (DIC) slider bay of a commercial microscope, without further additions required. We demonstrate with this device: 1) BSDF-based detection of Malarial parasites inside unstained human erythrocytes; 2) EF imaging with and without dichroic components, including detection of DAPI-stained Leishmania parasite without using excitation or emission filters; 3) RIC of black lipid membranes and other thin films, and 4) DFSR of patterned opaque and transparent surfaces. We believe that our design can expand the functionality of commercial bright field microscopes, provide easy field detection of parasites and be of interest to many users of light microscopy.

A Simple low-cost device enables four epi-illumination techniques on standard light microscopes

NASA Astrophysics Data System (ADS)

Ishmukhametov, Robert R.; Russell, Aidan N.; Wheeler, Richard J.; Nord, Ashley L.; Berry, Richard M.

2016-02-01

Back-scattering darkfield (BSDF), epi-fluorescence (EF), interference reflection contrast (IRC), and darkfield surface reflection (DFSR) are advanced but expensive light microscopy techniques with limited availability. Here we show a simple optical design that combines these four techniques in a simple low-cost miniature epi-illuminator, which inserts into the differential interference-contrast (DIC) slider bay of a commercial microscope, without further additions required. We demonstrate with this device: 1) BSDF-based detection of Malarial parasites inside unstained human erythrocytes; 2) EF imaging with and without dichroic components, including detection of DAPI-stained Leishmania parasite without using excitation or emission filters; 3) RIC of black lipid membranes and other thin films, and 4) DFSR of patterned opaque and transparent surfaces. We believe that our design can expand the functionality of commercial bright field microscopes, provide easy field detection of parasites and be of interest to many users of light microscopy.

Phase Sensitive Demodulation in Multiphoton Microscopy

NASA Astrophysics Data System (ADS)

Fisher, Walt G.; Piston, David W.; Wachter, Eric A.

2002-06-01

Multiphoton laser scanning microscopy offers advantages in depth of penetration into intact samples over other optical sectioning techniques. To achieve these advantages it is necessary to detect the emitted light without spatial filtering. In this nondescanned (nonconfocal) approach, ambient room light can easily contaminate the signal, forcing experiments to be performed in absolute darkness. For multiphoton microscope systems employing mode-locked lasers, signal processing can be used to reduce such problems by taking advantage of the pulsed characteristics of such lasers. Specifically, by recovering fluorescence generated at the mode-locked frequency, interference from stray light and other ambient noise sources can be significantly reduced. This technology can be adapted to existing microscopes by inserting demodulation circuitry between the detector and data collection system. The improvement in signal-to-noise ratio afforded by this approach yields a more robust microscope system and opens the possibility of moving multiphoton microscopy from the research lab to more demanding settings, such as the clinic.

Multispectral digital lensless holographic microscopy: from femtosecond laser to white light LED

NASA Astrophysics Data System (ADS)

Garcia-Sucerquia, J.

2015-04-01

The use of femtosecond laser radiation and super bright white LED in digital lensless holographic microscopy is presented. For the ultrafast laser radiation two different configurations of operation of the microscope are presented and the dissimilar performance of each one analyzed. The microscope operating with a super bright white light LED in combination with optical filters shows very competitive performance as it is compared with more expensive optical sources. The broadband emission of both radiation sources allows the multispectral imaging of biological samples to obtain spectral responses and/or full color images of the microscopic specimens; sections of the head of a Drosophila melanogaster fly are imaged in this contribution. The simple, solid, compact, lightweight, and reliable architecture of digital lensless holographic microscopy operating with broadband light sources to image biological specimens exhibiting micrometer-sized details is evaluated in the present contribution.

Light-sheet microscopy for everyone? Experience of building an OpenSPIM to study flatworm development.

PubMed

Girstmair, Johannes; Zakrzewski, Anne; Lapraz, François; Handberg-Thorsager, Mette; Tomancak, Pavel; Pitrone, Peter Gabriel; Simpson, Fraser; Telford, Maximilian J

2016-06-30

Selective plane illumination microscopy (SPIM a type of light-sheet microscopy) involves focusing a thin sheet of laser light through a specimen at right angles to the objective lens. As only the thin section of the specimen at the focal plane of the lens is illuminated, out of focus light is naturally absent and toxicity due to light (phototoxicity) is greatly reduced enabling longer term live imaging. OpenSPIM is an open access platform (Pitrone et al. 2013 and OpenSPIM.org) created to give new users step-by-step instructions on building a basic configuration of a SPIM microscope, which can in principle be adapted and upgraded to each laboratory's own requirements and budget. Here we describe our own experience with the process of designing, building, configuring and using an OpenSPIM for our research into the early development of the polyclad flatworm Maritigrella crozieri - a non-model animal. Our OpenSPIM builds on the standard design with the addition of two colour laser illumination for simultaneous detection of two probes/molecules and dual sided illumination, which provides more even signal intensity across a specimen. Our OpenSPIM provides high resolution 3d images and time lapse recordings, and we demonstrate the use of two colour lasers and the benefits of two color dual-sided imaging. We used our microscope to study the development of the embryo of the polyclad flatworm M. crozieri. The capabilities of our microscope are demonstrated by our ability to record the stereotypical spiral cleavage pattern of M. crozieri with high-speed multi-view time lapse imaging. 3D and 4D (3D + time) reconstruction of early development from these data is possible using image registration and deconvolution tools provided as part of the open source Fiji platform. We discuss our findings on the pros and cons of a self built microscope. We conclude that home-built microscopes, such as an OpenSPIM, together with the available open source software, such as MicroManager and Fiji, make SPIM accessible to anyone interested in having continuous access to their own light-sheet microscope. However, building an OpenSPIM is not without challenges and an open access microscope is a worthwhile, if significant, investment of time and money. Multi-view 4D microscopy is more challenging than we had expected. We hope that our experience gained during this project will help future OpenSPIM users with similar ambitions.

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed Central

Schröter, Tobias J.; Johnson, Shane B.; John, Kerstin; Santi, Peter A.

2011-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. PMID:22254177

Spin-Induced Polarizations and Nonreciprocal Directional Dichroism of the Room-Temperature Multiferroic BiFeO 3

DOE PAGES

Fishman, Randy Scott; Lee, Jun Hee; Bordacs, Sandor; ...

2015-09-14

A microscopic model for the room-temperature multiferroic BiFeO 3 that includes two Dzyaloshinskii-Moriya interactions and single-ion anisotropy along the ferroelectric polarization predicts both the zero-field spectroscopic modes as well as their splitting and evolution in a magnetic field. Due to simultaneously broken time-reversal and spatial-inversion symmetries, the absorption of light changes as the magnetic field or the direction of light propagation is reversed. We discuss three physical mechanisms that may contribute to this absorption asymmetry known as directional dichroism: the spin current, magnetostriction, and single-ion anisotropy. We conclude that the directional dichroism in BiFeO 3 is dominated by the spin-currentmore » polarization and is insensitive to the magnetostriction and easy-axis anisotropy. With three independent spin-current parameters, our model accurately describes the directional dichroism observed for magnetic field along [1, -1, 0]. Since some modes are almost transparent to light traveling in one direction but opaque for light traveling in the opposite direction, BiFeO 3 can be used as a room-temperature optical diode at certain frequencies in the GHz to THz range. This work demonstrates that an analysis of the directional dichroism spectra based on an effective spin model supplemented by first-principles calculations can produce a quantitative microscopic theory of the magnetoelectric couplings in multiferroic materials.« less

Spectro-microscopy of living plant cells.

PubMed

Harter, Klaus; Meixner, Alfred J; Schleifenbaum, Frank

2012-01-01

Spectro-microscopy, a combination of fluorescence microscopy with spatially resolved spectroscopic techniques, provides new and exciting tools for functional cell biology in living organisms. This review focuses on recent developments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context. The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassinosteroide receptor BRI1 in the plasma membrane of living plant cells. Moreover, the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime (FLT). Furthermore, a new spectro-microscopic technique, fluorescence intensity decay shape analysis microscopy (FIDSAM), has been developed. FIDSAM is capable of imaging low-expressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts. In addition, FIDSAM provides a very effective and sensitive tool on the basis of Förster resonance energy transfer (FRET) for the qualitative and quantitative determination of protein-protein interaction. Finally, we report on the quantitative analysis of the photosystem I and II (PSI/PSII) ratio in the chloroplasts of living Arabidopsis plants at room temperature, using high-resolution, spatially resolved fluorescence spectroscopy. With this technique, it was not only possible to measure PSI/PSII ratios, but also to demonstrate the differential competence of wild-type and carbohydrate-deficient plants to adapt the PSI/PSII ratio to different light conditions. In summary, the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches. Therefore, novel cell physiological and molecular topics can be addressed and valuable insights into molecular and subcellular processes can be obtained in living plants.

Evaluation of a new soft tipped injector for the implantation of foldable intraocular lenses.

PubMed

Kleinmann, Guy; Apple, David J

2007-08-01

To evaluate the R-INJ-04 soft-tipped injector, a new injector with an integral round nozzle manufactured by Rayner Intraocular Lenses, England. 16 Rayner C-flex intraocular lenses (IOLs; Rayner Intraocular lenses, England) ranging between +10 and +30 D (2 for each power) were tested. An ophthalmic viscoelastic device (Healon, AMO, Santa Ana, California, USA) was applied to the injectors. The IOLs were loaded according to the company injector's instructions for use and were injected into a Petri dish. After the injection, all the IOLs and nozzles were evaluated by gross (macroscopic) and microscopic analyses and photographed under a light microscope. One lens of each power and the cartridge used for the implantation were then sent for further analysis by scanning electron microscopy (SEM). The rest of the IOLs were tested for power and modulation transfer function (MTF). All the injections were successful. No damage to the IOLs or to the injectors was found by gross examination, light microscopy and SEM. No deposits were found on the IOL optical surfaces or haptics. Power and MTF analysis showed a close match with the original measurements. Our results suggest that the R-INJ-04 soft-tipped injector is safe for the implantation of the C-flex IOL with power range from 10 to 30 D. No structural damage to the IOLs or to the injectors was found, and the lens power and light transmission properties were not damaged in any way by the injection process.

Site of potential operating microscope light-induced phototoxicity on the human retina during temporal approach eye surgery.

PubMed

Pavilack, M A; Brod, R D

2001-02-01

To determine the site of focal illumination on the retina of phakic human cadaver eyes from an operating microscope positioned for temporal approach eye surgery. Experimental study. A Zeiss OPMI-6SFR operating microscope (Zeiss Humphrey Systems, Dublin, CA) was positioned over two phakic human cadaver eyes to measure the site of the focal illumination on the retina by directly observing the illumination on the posterior scleral surface of the globe. External localization of the foveola was made by direct observation using scleral indentation and indirect ophthalmoscopy. Various combinations of microscope angulation and field of view were analyzed. Distance of focal illumination from the operating room microscope relative to the foveola was measured. The diameter of the "hot spot" of focal illumination on the retina was 4.0 mm. With the eye positioned straight ahead and the level operating room microscope positioned for temporal approach eye surgery, the center of retinal illumination was 0.9 and 1.4 mm nasal relative to the foveola when the microscope field of view was centered over the cornea and temporal limbus, respectively. With the microscope angled 5, 10, 15, and 20 degrees temporally (oculars tilted toward surgeon), the center of the illumination was displaced nasal to the foveola by 1.1, 1.5, 3.8, and 5.1 mm, respectively, when the field of view was centered over the cornea and 1.5, 2.6, 4.7, and 6.0 mm, respectively, nasal to the foveola when centered over the temporal limbus. Retinal illumination from an operating microscope positioned for temporal approach eye surgery has the potential for light-induced injury to the fovea. Angulation of the operating microscope by up to 10 degrees temporally when the microscope field of view was centered over the cornea and up to 5 degrees temporally when centered over the temporal limbus was not adequate to displace the focal illumination off the foveola when the eye was in the straight-ahead position. Tilting the operating microscope 15 degrees or more temporally when centered on the pupil and 10 degrees or more when centered over the temporal limbus should safely displace the retinal light exposure away from the fovea during temporal approach surgery. Suggestions for reducing the risk of iatrogenic phototoxicity are reviewed.

Strength and deformability of light-toned layered deposits observed by MER Opportunity: Eagle to Erebus craters, Mars

NASA Astrophysics Data System (ADS)

Okubo, Chris H.

2007-10-01

Quantifying host rock deformation is vital to understanding the geologic evolution and productivity of subsurface fluid reservoirs. In support of on-going characterization of fracture controlled fluid flow through the light-toned layered deposits on Mars, key parameters of strength and deformability are derived from Microscopic Imager and Rock Abrasion Tool data collected by the Mars Exploration Rover Opportunity in Meridiani Planum. Analysis of 21 targets of light-toned layered deposits yields a median apparent porosity of 0.25. Additional physical parameters for each target are derived from these porosity measurements. The median value of unconfined compressive strength is 11.23 MPa, Young's modulus is 1.86 GPa, and the brittle-ductile transition pressure is 8.77 MPa.

Microscopy imaging device with advanced imaging properties

DOEpatents

Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

2015-11-24

Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

Microscopy imaging device with advanced imaging properties

DOEpatents

Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

2016-10-25

Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

Microscopy imaging device with advanced imaging properties

DOEpatents

Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

2016-11-22

Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

Microscopy imaging device with advanced imaging properties

DOEpatents

Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

2017-04-25

Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

Distribution of melanosomes across the retinal pigment epithelium of a hooded rat: implications for light damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howell, W.L.; Rapp, L.M.; Williams, T.P.

1982-02-01

Distribution of melanosomes across the retinal pigment epithelium of hooded rats (Long-Evans) is studied at the light microscopic and electron microscopic levels. This distribution is shown to be nonuniform: more melanosomes exist in the periphery than elsewhere and, importantly, there are very few melanosomes in a restricted area of the central portion of the superior hemisphere compared with the corresponding part of the inferior hemisphere. The region with fewest melanosomes is precisely the one that is highly susceptible to light damage. Because this region is the same in both pigmented and albino eyes, the paucity of melanin in this regionmore » is not the cause of its great sensitivity to light damage. Nor does light cause the nonuniform distribution of melanin. A possible explanation, involving a proposed vestigial tapetum, is given in order to explain the correlation of melanosome counts and sensitivity to light damage.« less

Calibrating excitation light fluxes for quantitative light microscopy in cell biology

PubMed Central

Grünwald, David; Shenoy, Shailesh M; Burke, Sean; Singer, Robert H

2011-01-01

Power output of light bulbs changes over time and the total energy delivered will depend on the optical beam path of the microscope, filter sets and objectives used, thus making comparison between experiments performed on different microscopes complicated. Using a thermocoupled power meter, it is possible to measure the exact amount of light applied to a specimen in fluorescence microscopy, regardless of the light source, as the light power measured can be translated into a power density at the sample. This widely used and simple tool forms the basis of a new degree of calibration precision and comparability of results among experiments and setups. Here we describe an easy-to-follow protocol that allows researchers to precisely estimate excitation intensities in the object plane, using commercially available opto-mechanical components. The total duration of this protocol for one objective and six filter cubes is 75 min including start-up time for the lamp. PMID:18974739

In situ microscopy for on-line determination of biomass.

PubMed

Bittner, C; Wehnert, G; Scheper, T

1998-10-05

A sensor is presented, which allows on-line microscopic observation of microorganisms during fermentations in bioreactors. This sensor, an In Situ Microscope (ISM) consists of a direct-light microscope with a measuring chamber, integrated in a 25 mm stainless steel tube, two CCD-cameras, and two frame-grabbers. The data obtained are processed by an automatic image analysis system. The ISM is connected with the bioreactor via a standard port, and it is immersed directly in the culture liquid-in our case Saccharomyces cerevisiae in a synthetic medium. The microscopic examination of the liquid is performed in the measuring chamber, which is situated near the front end of the sensor head. The measuring chamber is opened and closed periodically. In the open state, the liquid in the bioreactor flows unrestricted through the chamber. In closing, a defined volume of 2,2. 10(-8) mL of the liquid becomes enclosed. After a few seconds, when the movement of the cells in the enclosed culture has stopped, they are examined with the microscope. The microscopic images of the cells are registered with the CCD-cameras and are visualized on a monitor, allowing a direct view of the cell population. After detection, the measuring chamber reopens, and the enclosed liquid is released. The images obtained are evaluated as to cell concentration, cell size, cell volume, biomass, and other relevant parameters simultaneously by automatic image analysis. With a PC (486/33 MHz), image processing takes about 15 s per image. The detection range tested when measuring cells of S. cerevisiae is about 10(6) to 10(9) cells/mL (equivalent to a biomass of 0.01 g/L to 12 g/L). The calculated biomass values correlate very well with those obtained using dry weight analysis. Furthermore, histograms can be calculated, which are comparable to those obtained by flow cytometry. Copyright 1998 John Wiley & Sons, Inc.

Automated measurement of diatom size

USGS Publications Warehouse

Spaulding, Sarah A.; Jewson, David H.; Bixby, Rebecca J.; Nelson, Harry; McKnight, Diane M.

2012-01-01

Size analysis of diatom populations has not been widely considered, but it is a potentially powerful tool for understanding diatom life histories, population dynamics, and phylogenetic relationships. However, measuring cell dimensions on a light microscope is a time-consuming process. An alternative technique has been developed using digital flow cytometry on a FlowCAM® (Fluid Imaging Technologies) to capture hundreds, or even thousands, of images of a chosen taxon from a single sample in a matter of minutes. Up to 30 morphological measures may be quantified through post-processing of the high resolution images. We evaluated FlowCAM size measurements, comparing them against measurements from a light microscope. We found good agreement between measurement of apical cell length in species with elongated, straight valves, including small Achnanthidium minutissimum (11-21 µm) and largeDidymosphenia geminata (87–137 µm) forms. However, a taxon with curved cells, Hannaea baicalensis (37–96 µm), showed differences of ~ 4 µm between the two methods. Discrepancies appear to be influenced by the choice of feret or geodesic measurement for asymmetric cells. We describe the operating conditions necessary for analysis of size distributions and present suggestions for optimal instrument conditions for size analysis of diatom samples using the FlowCAM. The increased speed of data acquisition through use of imaging flow cytometers like the FlowCAM is an essential step for advancing studies of diatom populations.

Effects of photodynamic therapy on Gram-positive and Gram-negative bacterial biofilms by bioluminescence imaging and scanning electron microscopic analysis.

PubMed

Garcez, Aguinaldo S; Núñez, Silvia C; Azambuja, Nilton; Fregnani, Eduardo R; Rodriguez, Helena M H; Hamblin, Michael R; Suzuki, Hideo; Ribeiro, Martha S

2013-11-01

The aim of this study was to test photodynamic therapy (PDT) as an alternative approach to biofilm disruption on dental hard tissue, We evaluated the effect of methylene blue and a 660 nm diode laser on the viability and architecture of Gram-positive and Gram-negative bacterial biofilms. Ten human teeth were inoculated with bioluminescent Pseudomonas aeruginosa or Enterococcus faecalis to form 3 day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify and evaluate the bacterial viability, and scanning electron microscopic (SEM) imaging was used to assess architecture and morphology of bacterial biofilm before and after PDT employing methylene blue and 40 mW, 660 nm diode laser light delivered into the root canal via a 300 μm fiber for 240 sec, resulting in a total energy of 9.6 J. The data were statistically analyzed with analysis of variance (ANOVA) followed by Tukey test. The bacterial reduction showed a dose dependence; as the light energy increased, the bioluminescence decreased in both planktonic suspension and in biofilms. The SEM analysis showed a significant reduction of biofilm on the surface. PDT promoted disruption of the biofilm and the number of adherent bacteria was reduced. The photodynamic effect seems to disrupt the biofilm by acting both on bacterial cells and on the extracellular matrix.

Microscopic image analysis for reticulocyte based on watershed algorithm

NASA Astrophysics Data System (ADS)

Wang, J. Q.; Liu, G. F.; Liu, J. G.; Wang, G.

2007-12-01

We present a watershed-based algorithm in the analysis of light microscopic image for reticulocyte (RET), which will be used in an automated recognition system for RET in peripheral blood. The original images, obtained by micrography, are segmented by modified watershed algorithm and are recognized in term of gray entropy and area of connective area. In the process of watershed algorithm, judgment conditions are controlled according to character of the image, besides, the segmentation is performed by morphological subtraction. The algorithm was simulated with MATLAB software. It is similar for automated and manual scoring and there is good correlation(r=0.956) between the methods, which is resulted from 50 pieces of RET images. The result indicates that the algorithm for peripheral blood RETs is comparable to conventional manual scoring, and it is superior in objectivity. This algorithm avoids time-consuming calculation such as ultra-erosion and region-growth, which will speed up the computation consequentially.

An historical account of the development and applications of the negative staining technique to the electron microscopy of viruses.

PubMed

Horne, R W; Wildy, P

1979-09-01

A brief historical account of the development and applications of the negative staining techniques to the study of the structure of viruses and their components as observed in the electron microscope is presented. Although the basic method of surrounding or embedding specimens in opaque dyes was used in light microscopy dating from about 1884, the equivalent preparative techniques applied to electron microscopy were comparatively recent. The combination of experiments on a sophisticated bacterial virus and the installation of a high resolution electron microscope in the Cavendish Laboratory, Cambridge, during 1954, subsequently led to the analysis of several important morphological features of animal, plant and bacterial viruses. The implications of the results from these early experiments on viruses and recent developments in negative staining methods for high resolution image analysis of electron micrographs are also discussed.

Low-frequency nondestructive analysis of cracks in multilayer structures using a scanning magnetic microscope

NASA Astrophysics Data System (ADS)

Adamo, M.; Nappi, C.; Sarnelli, E.

2010-09-01

The use of a scanning magnetic microscope (SMM) with a high temperature superconducting quantum interference device (SQUID) for quantitative measurements in eddy current nondestructive analysis (NDA) is presented. The SQUID has been used to detect the weak magnetic field variations around a small defect, close to a structural part generating an intensive magnetic field. The experimental data for a deep crack close to a rivet in a multilayer conducting plate have been taken in a RF-shielded environment and discussed in the light of the theoretical predictions. The results show that eddy current NDA can distinguish subsurface crack signals from wider structural signals, with defects located 10 mm below the surface. Moreover, in order to visualize the structure of the probing current when a circular induction coil is used, the simulation of eddy currents in a thick unflawed conducting plate has been carried out.

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, Evgeny

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

Microscope-Based Fluid Physics Experiments in the Fluids and Combustion Facility on ISS

NASA Technical Reports Server (NTRS)

Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Malarik, Diane C.

2000-01-01

At the NASA Glenn Research Center, the Microgravity Science Program is planning to conduct a large number of experiments on the International Space Station in both the Fluid Physics and Combustion Science disciplines, and is developing flight experiment hardware for use within the International Space Station's Fluids and Combustion Facility. Four fluids physics experiments that require an optical microscope will be sequentially conducted within a subrack payload to the Fluids Integrated Rack of the Fluids and Combustion Facility called the Light Microscopy Module, which will provide the containment, changeout, and diagnostic capabilities to perform the experiments. The Light Microscopy Module is planned as a fully remotely controllable on-orbit microscope facility, allowing flexible scheduling and control of experiments within International Space Station resources. This paper will focus on the four microscope-based experiments, specifically, their objectives and the sample cell and instrument hardware to accommodate their requirements.

Comparisons between conventional optical imaging and parametric indirect microscopic imaging on human skin detection

NASA Astrophysics Data System (ADS)

Liu, Guoyan; Gao, Kun; Liu, Xuefeng; Ni, Guoqiang

2016-10-01

We report a new method, polarization parameters indirect microscopic imaging with a high transmission infrared light source, to detect the morphology and component of human skin. A conventional reflection microscopic system is used as the basic optical system, into which a polarization-modulation mechanics is inserted and a high transmission infrared light source is utilized. The near-field structural characteristics of human skin can be delivered by infrared waves and material coupling. According to coupling and conduction physics, changes of the optical wave parameters can be calculated and curves of the intensity of the image can be obtained. By analyzing the near-field polarization parameters in nanoscale, we can finally get the inversion images of human skin. Compared with the conventional direct optical microscope, this method can break diffraction limit and achieve a super resolution of sub-100nm. Besides, the method is more sensitive to the edges, wrinkles, boundaries and impurity particles.

[Phenotype-based primary screening for drugs promoting neuronal subtype differentiation in embryonic stem cells with light microscope].

PubMed

Gao, Yi-ning; Wang, Dan-ying; Pan, Zong-fu; Mei, Yu-qin; Wang, Zhi-qiang; Zhu, Dan-yan; Lou, Yi-jia

2012-07-01

To set up a platform for phenotype-based primary screening of drug candidates promoting neuronal subtype differentiation in embryonic stem cells (ES) with light microscope. Hanging drop culture 4-/4+ method was employed to harvest the cells around embryoid body (EB) at differentiation endpoint. Morphological evaluation for neuron-like cells was performed with light microscope. Axons for more than three times of the length of the cell body were considered as neuron-like cells. The compound(s) that promote neuron-like cells was further evaluated. Icariin (ICA, 10(-6)mol/L) and Isobavachin (IBA, 10(-7)mol/L) were selected to screen the differentiation-promoting activity on ES cells. Immunofluorescence staining with specific antibodies (ChAT, GABA) was used to evaluate the neuron subtypes. The cells treated with IBA showed neuron-like phenotype, but the cells treated with ICA did not exhibit the morphological changes. ES cells treated with IBA was further confirmed to be cholinergic and GABAergic neurons. Phenotypic screening with light microscope for molecules promoting neuronal differentiation is an effective method with advantages of less labor and material consuming and time saving, and false-positive results derived from immunofluorescence can be avoided. The method confirms that IBA is able to facilitate ES cells differentiating into neuronal cells, including cholinergic neurons and GABAergic neurons.

Ultrastructural characterization of pulmonary neoplasms. II. The role of electron microscopy in characterization of uncommon epithelial pulmonary neoplasms, metastatic neoplasms to and from lung, and other tumors, including mesenchymal neoplasms.

PubMed

Herrera, G A; Alexander, C B; Jones, J M

1985-01-01

Ultrastructural analysis through better resolution adds significant information to the evaluation and classification of primary pulmonary neoplasms. Light microscopy is limited in the evaluation of lung neoplasms. In some cases the light microscopic appearance may be entirely misleading, whereas in others it is inconclusive. Immunocytochemistry provides information on cytoplasmic differentiation of various tumors and hence more data on their corresponding phenotypes. The data from immunocytochemistry without corresponding objective electron microscopic evaluation may be very difficult to interpret. Correlation of historical, gross, light, electron microscopic, and immunocytochemical data is essential for a final accurate diagnosis (fig. 20). Fine needle aspiration of pulmonary neoplasms is becoming very fashionable and a diagnosis, including type of neoplasm, is expected on the basis of examination of a limited number of cells which further emphasizes the importance of ultrastructural characterization in helping to establish an accurate diagnosis [63-69]. The current classification of pulmonary neoplasms may need to be modified in the near future to incorporate the newly created data [70-72]. At the present time, there appears to be, at least, a need for a 'double standard', as Sobin [73] has suggested, which would permit the evaluation of the biologic significance of the ultrastructural and immunocytochemical findings (as applied to classification of neoplasms) in an effort to derive meaningful clinicopathologic correlations. Figure 20 emphasizes the additive role which should be played by the various diagnostic modalities to enable a morphologic assessment which would be an accurate predictor of biologic behavior. With an accurate assessment of biologic behavior, a more appropriate and rational approach for therapy is possible. There is also an important role for ultrastructural analysis in metastatic pleural and pulmonary neoplasms, primarily adenocarcinomas, as well as in the differential diagnosis of pulmonary neoplasms versus other tumors that may be similar in histological appearance. The role of ultrastructure in mesenchymal neoplasms is also crucial in defining specific neoplastic cell populations and in some cases in the differentiation from other non-mesenchymal tumors. It seems that routine electron microscopic examination of pulmonary neoplasms provides additional information that may be of great value in the management of patients and in understanding the differentiation, and perhaps histogenesis, of pulmonary neoplasms.(ABSTRACT TRUNCATED AT 400 WORDS)

From Animaculum to single molecules: 300 years of the light microscope

PubMed Central

Wollman, Adam J. M.; Nudd, Richard; Hedlund, Erik G.; Leake, Mark C.

2015-01-01

Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632–1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term ‘biologists’). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739 Phil. Trans. 41, 503–519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800 The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition of Open Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the last ca 300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants. PMID:25924631

Use of a night vision intensifier for direct visualization by eye of far-red and near-infrared fluorescence through an optical microscope.

PubMed

Siddiqi, M A; Kilduff, G M; Gearhart, J D

2003-11-01

We describe the design, construction and testing of a prototype device that allows the direct visualization by eye of far-red and near-infrared (NIR) fluorescence through an optical microscope. The device incorporates a gallium arsenide (GaAs) image intensifier, typically utilized in low-light or 'night vision' applications. The intensifier converts far-red and NIR light into electrons and then into green light, which is visible to the human eye. The prototype makes possible the direct, real-time viewing by eye of normally invisible far-red and NIR fluorescence from a wide variety of fluorophores, using the full field of view of the microscope to which it is applied. The high sensitivity of the image intensifier facilitates the viewing of a wide variety of photosensitive specimens, including live cells and embryos, at vastly reduced illumination levels in both fluorescence and bright-field microscopy. Modifications to the microscope are not required in order to use the prototype, which is fully compatible with all current fluorescence techniques. Refined versions of the prototype device will have broad research and clinical applications.

Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

PubMed

Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

2016-11-14

A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

Microscopic video observation of capillary vessel systems using diffuse back lighting

NASA Astrophysics Data System (ADS)

Sakai, Minako; Arai, Hiroki; Iwai, Toshiaki

2017-04-01

We have been developing a simple and practical video microscopy system based on absorption spectra of biological substance to perform spectroscopic observation of living tissues. The diffuse backlighting effect is actively used in the developed system, which is generated by multiple light scattering in the tissue. It is demonstrated that the light specularly reflected from the skin surface can be completely suppressed in the microscopic observation and the biological activity of the capillary vessel systems distributed under the skin can be successfully observed. As a result, we can confirm the effectiveness of the video microscopy system using diffuse backlighting and the applicability of our developed system.

Use of digital micromirror devices as dynamic pinhole arrays for adaptive confocal fluorescence microscopy

NASA Astrophysics Data System (ADS)

Pozzi, Paolo; Wilding, Dean; Soloviev, Oleg; Vdovin, Gleb; Verhaegen, Michel

2018-02-01

In this work, we present a new confocal laser scanning microscope capable to perform sensorless wavefront optimization in real time. The device is a parallelized laser scanning microscope in which the excitation light is structured in a lattice of spots by a spatial light modulator, while a deformable mirror provides aberration correction and scanning. A binary DMD is positioned in an image plane of the detection optical path, acting as a dynamic array of reflective confocal pinholes, images by a high performance cmos camera. A second camera detects images of the light rejected by the pinholes for sensorless aberration correction.

Coherent anti-Stokes Raman scattering spectroscope/microscope based on a widely tunable laser source

NASA Astrophysics Data System (ADS)

Dementjev, A.; Gulbinas, V.; Serbenta, A.; Kaucikas, M.; Niaura, G.

2010-03-01

We present a coherent anti-Stokes Raman scattering (CARS) microscope based on a robust and simple laser source. A picosecond laser operating in a cavity dumping regime at the 1 MHz repetition rate was used to pump a traveling wave optical parametric generator, which serves as a two-color excitation light source for the CARS microscope. We demonstrate the ability of the presented CARS microscope to measure CARS spectra and images by using several detection schemes.

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

ScienceCinema

Nazaretski, Evgeny

2018-06-13

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation

DTIC Science & Technology

2012-08-01

early rejection of the grafts, there was no significant functional recovery noted on electromyography or Catwalk gait analysis. However, in vitro...Figure 10: Light Microscopic Image (100X, stained with Toluidine Blue): Nerve Cross Section 5-8 mm distal to anastomosis site. Representative... images from (A) Systemic MSC therapy, (B) Local MSC therapy and (c) No treatment Control Figure 11: Sciatic Nerve Transection and Repair (6

Cytohistological study of the leaf structures of Panax ginseng Meyer and Panax quinquefolius L.

PubMed

Lee, Ok Ran; Nguyen, Ngoc Quy; Lee, Kwang Ho; Kim, Young Chang; Seo, Jiho

2017-10-01

Both Panax ginseng Meyer and Panax quinquefolius are obligate shade-loving plants whose natural habitats are broadleaved forests of Eastern Asia and North America. Panax species are easily damaged by photoinhibition when they are exposed to high temperatures or insufficient shade. In this study, a cytohistological study of the leaf structures of two of the most well-known Panax species was performed to better understand the physiological processes that limit photosynthesis. Leaves of ginseng plants grown in soil and hydroponic culture were sectioned for analysis. Leaf structures of both Panax species were observed using a light microscope, scanning electron microscope, and transmission electron microscope. The mesostructure of both P. ginseng and P. quinquefolius frequently had one layer of noncylindrical palisade cells and three or four layers of spongy parenchymal cells. P. quinquefolius contained a similar number of stomata in the abaxial leaf surface but more tightly appressed enlarged grana stacks than P. ginseng contained. The adaxial surface of the epidermis in P. quinquefolius showed cuticle ridges with a pattern similar to that of P. ginseng . The anatomical leaf structure of both P. ginseng and P. quinquefolius shows that they are typical shade-loving sciophytes. Slight differences in chloroplast structure suggests that the two different species can be authenticated using transmission electron microscopy images, and light-resistant cultivar breeding can be performed via controlling photosynthesis efficiency.

Investigation of skin structures based on infrared wave parameter indirect microscopic imaging

NASA Astrophysics Data System (ADS)

Zhao, Jun; Liu, Xuefeng; Xiong, Jichuan; Zhou, Lijuan

2017-02-01

Detailed imaging and analysis of skin structures are becoming increasingly important in modern healthcare and clinic diagnosis. Nanometer resolution imaging techniques such as SEM and AFM can cause harmful damage to the sample and cannot measure the whole skin structure from the very surface through epidermis, dermis to subcutaneous. Conventional optical microscopy has the highest imaging efficiency, flexibility in onsite applications and lowest cost in manufacturing and usage, but its image resolution is too low to be accepted for biomedical analysis. Infrared parameter indirect microscopic imaging (PIMI) uses an infrared laser as the light source due to its high transmission in skins. The polarization of optical wave through the skin sample was modulated while the variation of the optical field was observed at the imaging plane. The intensity variation curve of each pixel was fitted to extract the near field polarization parameters to form indirect images. During the through-skin light modulation and image retrieving process, the curve fitting removes the blurring scattering from neighboring pixels and keeps only the field variations related to local skin structures. By using the infrared PIMI, we can break the diffraction limit, bring the wide field optical image resolution to sub-200nm, in the meantime of taking advantage of high transmission of infrared waves in skin structures.

Microscopic analysis of Spodoptera frugiperda (Lepidoptera: Noctuidae) embryonic development before and after treatment with azadirachtin, lufenuron, and deltamethrin.

PubMed

Correia, Alicely A; Wanderley-Teixeira, Valéria; Teixeira, Alvaro A C; Oliveira, José V; Gonçalves, Gabriel G A; Cavalcanti, MaríIia G S; Brayner, Fábio A; Alves, Luiz C

2013-04-01

The botanical insecticides, growth regulators, and pyrethroids have an effect on the biology of Spodoptera frugiperda (Smith). However, no emphasis has been given to the effect of these insecticides on embryonic development of insects, in histological level. Thus, this research aimed to examine by light and scanning electron microscopy S. frugiperda eggs and to describe the embryonic development, before and after immersion treatment, using commercial concentrations and lower concentrations than commercial ones, of the compounds lufenuron (Match), azadirachtin (AzaMax), and deltamethrin (Decis-positive control). For light microscopy semithin sections of eggs were used, and for scanning electron microscopy, images of the surface of eggs, treated and untreated with insecticides. The morphological characteristics of S. frugiperda eggs, in general, were similar to those described in the literature for most of the insects in the order Lepidoptera. Spherical eggs slightly flattened at the poles, with chorion, yolk, vitelline membrane, and embryo formation. In both microscopic analysis, we observed that insecticides acted immediately and independent of concentration, resulting absence, or incomplete embryo, presented yolk granules widely dispersed, without vitellophage formation, chorion disintegration, disorganized blastoderm, presenting vacuoles, yolk region with amorphous cells, and formation of completely uncharacterized appendages. Thus, we conclude that the compounds lufenuron and azadirachtin interfere on S. frugiperda embryonic development.

Scanless nonlinear optical microscope for image reconstruction and space-time correlation analysis

NASA Astrophysics Data System (ADS)

Ceffa, N. G.; Radaelli, F.; Pozzi, P.; Collini, M.; Sironi, L.; D'alfonso, L.; Chirico, G.

2017-06-01

Optical Microscopy has been applied to life science from its birth and reached widespread application due to its major advantages: limited perturbation of the biological tissue and the easy accessibility of the light sources. However, as the spatial and time resolution requirements and the time stability of the microscopes increase, researchers are struggling against some of its limitations: limited transparency and the refractivity of the living tissue to light and the field perturbations induced by the path in the tissue. We have developed a compact stand-alone, completely scan-less, optical setup that allows to acquire non-linear excitation images and to measure the sample dynamics simultaneously on an ensemble of arbitrary chosen regions of interests. The image is obtained by shining a square array of spots on the sample obtained by a spatial light modulator and by shifting it (10 ms refresh time) on the sample. The final image is computed from the superposition of (100-1000) images. Filtering procedures can be applied to the raw images of the excitation array before building the image. We discuss results that show how this setup can be used for the correction of wave front aberrations induced by turbid samples (such as living tissues) and for the computation of space-time cross-correlations in complex networks.

Phase-shifting interference microscope with extendable field of measurement

NASA Astrophysics Data System (ADS)

Lin, Shyh-Tsong; Hsu, Wei-Feng; Wang, Ming-Shiang

2018-04-01

An innovative phase-shifting interference microscope aimed at extending the field of measurement is proposed in this paper. The microscope comprises a light source module, a phase modulation module, and an interferometric module, which reconstructs the micro-structure contours of samples using the five-step phase-shifting algorithm. This paper discusses the measurement theory and outlines the configuration, experimental setup, and experimental results obtained using the proposed interference microscope. The results confirm the efficacy of the microscope, achieving a standard deviation of 2.4 nm from a step height of 86.2 nm in multiple examinations.

Hybrid Al/steel-joints manufactured by ultrasound enhanced friction stir welding (USE-FSW): Process comparison, nondestructive testing and microscopic analysis

NASA Astrophysics Data System (ADS)

Thomä, M.; Wagner, G.; Straß, B.; Wolter, B.; Benfer, S.; Fürbeth, W.

2017-03-01

The process of friction stir welding (FSW) is an innovative joining technique, which proved its potential in joining dissimilar metals that are poorly fusion weldable. This ability opens a wide range for applications in industrial fields, where weight reduction by partial substitution of conventional materials through lightweight materials is a current central aim. As a consequence of this, the realization of aluminum / steel-joints is of great interest. For this material compound, several friction stir welds were carried out by different researchers for varying Al/steel-joints, whereas the definition of optimal process parameters as well as the increase of mechanical properties was in the focus of the studies. To achieve further improved properties for this dissimilar joint a newly developed hybrid process named “ultrasound enhanced friction stir welding (USE-FSW)” was applied. In this paper the resulting properties of Al/steel-joints using FSW and USE-FSW will be presented and compared. Furthermore, first results by using the nondestructive testing method “computer laminography” to analyze the developed joining area will be shown supplemented by detailed light-microscopic investigations, scanning electron microscopic analysis, and EDX.

The Light Microscopy Module: An On-Orbit Multi-User Microscope Facility

NASA Technical Reports Server (NTRS)

Motil, Susan M.; Snead, John H.

2002-01-01

The Light Microscopy Module (LMM) is planned as a remotely controllable on-orbit microscope subrack facility, allowing flexible scheduling and operation of fluids and biology experiments within the Fluids and Combustion Facility (FCF) Fluids Integrated Rack (FIR) on the International Space Station (ISS). The LMM will be the first integrated payload with the FIR to conduct four fluid physics experiments. A description of the LMM diagnostic capabilities, including video microscopy, interferometry, laser tweezers, confocal, and spectrophotometry, will be provided.

Dual-mode optical microscope based on single-pixel imaging

NASA Astrophysics Data System (ADS)

Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

2016-07-01

We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

Ultrawidefield microscope for high-speed fluorescence imaging and targeted optogenetic stimulation.

PubMed

Werley, Christopher A; Chien, Miao-Ping; Cohen, Adam E

2017-12-01

The rapid increase in the number and quality of fluorescent reporters and optogenetic actuators has yielded a powerful set of tools for recording and controlling cellular state and function. To achieve the full benefit of these tools requires improved optical systems with high light collection efficiency, high spatial and temporal resolution, and patterned optical stimulation, in a wide field of view (FOV). Here we describe our 'Firefly' microscope, which achieves these goals in a Ø6 mm FOV. The Firefly optical system is optimized for simultaneous photostimulation and fluorescence imaging in cultured cells. All but one of the optical elements are commercially available, yet the microscope achieves 10-fold higher light collection efficiency at its design magnification than the comparable commercially available microscope using the same objective. The Firefly microscope enables all-optical electrophysiology ('Optopatch') in cultured neurons with a throughput and information content unmatched by other neuronal phenotyping systems. This capability opens possibilities in disease modeling and phenotypic drug screening. We also demonstrate applications of the system to voltage and calcium recordings in human induced pluripotent stem cell derived cardiomyocytes.

Ultrawidefield microscope for high-speed fluorescence imaging and targeted optogenetic stimulation

PubMed Central

Werley, Christopher A.; Chien, Miao-Ping; Cohen, Adam E.

2017-01-01

The rapid increase in the number and quality of fluorescent reporters and optogenetic actuators has yielded a powerful set of tools for recording and controlling cellular state and function. To achieve the full benefit of these tools requires improved optical systems with high light collection efficiency, high spatial and temporal resolution, and patterned optical stimulation, in a wide field of view (FOV). Here we describe our ‘Firefly’ microscope, which achieves these goals in a Ø6 mm FOV. The Firefly optical system is optimized for simultaneous photostimulation and fluorescence imaging in cultured cells. All but one of the optical elements are commercially available, yet the microscope achieves 10-fold higher light collection efficiency at its design magnification than the comparable commercially available microscope using the same objective. The Firefly microscope enables all-optical electrophysiology (‘Optopatch’) in cultured neurons with a throughput and information content unmatched by other neuronal phenotyping systems. This capability opens possibilities in disease modeling and phenotypic drug screening. We also demonstrate applications of the system to voltage and calcium recordings in human induced pluripotent stem cell derived cardiomyocytes. PMID:29296505

Holographic pixel super-resolution in portable lensless on-chip microscopy using a fiber-optic array.

PubMed

Bishara, Waheb; Sikora, Uzair; Mudanyali, Onur; Su, Ting-Wei; Yaglidere, Oguzhan; Luckhart, Shirley; Ozcan, Aydogan

2011-04-07

We report a portable lensless on-chip microscope that can achieve <1 µm resolution over a wide field-of-view of ∼ 24 mm(2) without the use of any mechanical scanning. This compact on-chip microscope weighs ∼ 95 g and is based on partially coherent digital in-line holography. Multiple fiber-optic waveguides are butt-coupled to light emitting diodes, which are controlled by a low-cost micro-controller to sequentially illuminate the sample. The resulting lensfree holograms are then captured by a digital sensor-array and are rapidly processed using a pixel super-resolution algorithm to generate much higher resolution holographic images (both phase and amplitude) of the objects. This wide-field and high-resolution on-chip microscope, being compact and light-weight, would be important for global health problems such as diagnosis of infectious diseases in remote locations. Toward this end, we validate the performance of this field-portable microscope by imaging human malaria parasites (Plasmodium falciparum) in thin blood smears. Our results constitute the first-time that a lensfree on-chip microscope has successfully imaged malaria parasites.

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed

Schröter, Tobias J; Johnson, Shane B; John, Kerstin; Santi, Peter A

2012-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. 2011 Optical Society of America

Low efficiency upconversion nanoparticles for high-resolution coalignment of near-infrared and visible light paths on a light microscope

PubMed Central

Sundaramoorthy, Sriramkumar; Badaracco, Adrian Garcia; Hirsch, Sophia M.; Park, Jun Hong; Davies, Tim; Dumont, Julien; Shirasu-Hiza, Mimi; Kummel, Andrew C.; Canman, Julie C.

2017-01-01

The combination of near infrared (NIR) and visible wavelengths in light microscopy for biological studies is increasingly common. For example, many fields of biology are developing the use of NIR for optogenetics, in which an NIR laser induces a change in gene expression and/or protein function. One major technical barrier in working with both NIR and visible light on an optical microscope is obtaining their precise coalignment at the imaging plane position. Photon upconverting particles (UCPs) can bridge this gap as they are excited by NIR light but emit in the visible range via an anti-Stokes luminescence mechanism. Here, two different UCPs have been identified, high-efficiency micro540-UCPs and lower efficiency nano545-UCPs, that respond to NIR light and emit visible light with high photostability even at very high NIR power densities (>25,000 Suns). Both of these UCPs can be rapidly and reversibly excited by visible and NIR light and emit light at visible wavelengths detectable with standard emission settings used for Green Fluorescent Protein (GFP), a commonly used genetically-encoded fluorophore. However, the high efficiency micro540-UCPs were suboptimal for NIR and visible light coalignment, due to their larger size and spatial broadening from particle-to-particle energy transfer consistent with a long lived excited state and saturated power dependence. In contrast, the lower efficiency nano-UCPs were superior for precise coalignment of the NIR beam with the visible light path (~2 µm versus ~8 µm beam broadening respectively) consistent with limited particle-to-particle energy transfer, superlinear power dependence for emission, and much smaller particle size. Furthermore, the nano-UCPs were superior to a traditional two-camera method for NIR and visible light path alignment in an in vivo Infrared-Laser-Evoked Gene Operator (IR-LEGO) optogenetics assay in the budding yeast S. cerevisiae. In summary, nano-UCPs are powerful new tools for coaligning NIR and visible light paths on a light microscope. PMID:28221018

Optical anisotropy and domain structure of multiferroic Ni-Mn-Ga and Co-Ni-Ga Heusler-type alloys

NASA Astrophysics Data System (ADS)

Ivanova, A. I.; Gasanov, O. V.; Kaplunova, E. I.; Kalimullina, E. T.; Zalyotov, A. B.; Grechishkin, R. M.

2015-03-01

A study is made of the reflectance anisotropy of martensitic and magnetic domains in ferromagnetic shape memory alloys (FSMA) Ni-Mn-Ga and Co-Ni-Ga. The reflectance of metallographic sections of these alloys was measured in the visible with the aid of standard inverted polarized light microscope with a 360° rotatable specimen stage. Calculations are presented for the estimation of image contrast values between neighboring martensite twins. Qualitative and quantitative observations and angular measurements in reflected polarized light proved to be useful for the analysis of specific features of the martensite microstructure of multiferroic materials.

A compact light-sheet microscope for the study of the mammalian central nervous system

PubMed Central

Yang, Zhengyi; Haslehurst, Peter; Scott, Suzanne; Emptage, Nigel; Dholakia, Kishan

2016-01-01

Investigation of the transient processes integral to neuronal function demands rapid and high-resolution imaging techniques over a large field of view, which cannot be achieved with conventional scanning microscopes. Here we describe a compact light sheet fluorescence microscope, featuring a 45° inverted geometry and an integrated photolysis laser, that is optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We demonstrate the utility of this design for three-dimensional morphological reconstruction, activation of a single synapse with localized photolysis, and fast imaging of neuronal Ca2+ signalling across a large field of view. The developed system opens up a host of novel applications for the neuroscience community. PMID:27215692

Development of an ultralow-light-level luminescence image analysis system for dynamic measurements of transcriptional activity in living and migrating cells.

PubMed

Maire, E; Lelièvre, E; Brau, D; Lyons, A; Woodward, M; Fafeur, V; Vandenbunder, B

2000-04-10

We have developed an approach to study in single living epithelial cells both cell migration and transcriptional activation, which was evidenced by the detection of luminescence emission from cells transfected with luciferase reporter vectors. The image acquisition chain consists of an epifluorescence inverted microscope, connected to an ultralow-light-level photon-counting camera and an image-acquisition card associated to specialized image analysis software running on a PC computer. Using a simple method based on a thin calibrated light source, the image acquisition chain has been optimized following comparisons of the performance of microscopy objectives and photon-counting cameras designed to observe luminescence. This setup allows us to measure by image analysis the luminescent light emitted by individual cells stably expressing a luciferase reporter vector. The sensitivity of the camera was adjusted to a high value, which required the use of a segmentation algorithm to eliminate the background noise. Following mathematical morphology treatments, kinetic changes of luminescent sources were analyzed and then correlated with the distance and speed of migration. Our results highlight the usefulness of our image acquisition chain and mathematical morphology software to quantify the kinetics of luminescence changes in migrating cells.

HIGH TEMPERATURE MICROSCOPE AND FURNACE

DOEpatents

Olson, D.M.

1961-01-31

A high-temperature microscope is offered. It has a reflecting optic situated above a molten specimen in a furnace and reflecting the image of the same downward through an inert optic member in the floor of the furnace, a plurality of spaced reflecting plane mirrors defining a reflecting path around the furnace, a standard microscope supported in the path of and forming the end terminus of the light path.

Colonization of cashew plants by Lasiodiplodia theobromae: Microscopical features

USDA-ARS?s Scientific Manuscript database

Lasiodiplodia theobromae is a phytopathogenic fungus causing gummosis, a threatening disease for cashew plants in Brazil. In an attempt to investigate the ultrastructural features of the pathogen colonization and its response to immunofluorescence labeling, light, confocal and electron microscope st...

Fluorescence-guided resection of intracranial VX2 tumor in a preclinical model using 5-aminolevulinic acid (ALA): preliminary results

NASA Astrophysics Data System (ADS)

Bogaards, Arjen; Varma, Abhay; Moriyama, Eduardo H.; Lin, Annie; Giles, Anoja; Bisland, Stuart K.; Lilge, Lothar D.; Bilbao, G. M.; Muller, Paul J.; Wilson, Brian C.

2003-06-01

Fluorescence-guided brain tumor resection may help the neurosurgeon to identify tumor margins that merge imperceptibly into the normal brain tissue and are difficult to identify under white light illumination even using an operating microscope. We compared the amount of residual tumor after white light resection using an operating microscope versus that after fluorescnece-guided resection of an intracranial VX2 tumor in a preclinical model using our previously developed co-axial fluorscence imaging and spectroscopy system, exciting and detecting PpIX fluorescence at 405nm and 635nm respectively. Preliminary results: No fluorescence was present in 3 non-tumor-bearing animals. Fluorescence was present in all 15 tumor-bearing animals after white light resection was completed. To date in 4 rabbits, a decrease in residual tumor was found when using additional fluorescence guided resection compared to white light resection only. Conclusions: ALA induced PpIX fluorescence detects tumor margins not seen under an operation microscope using while light. Using fluorescence imaging to guide tumor resection resulted in a 3-fold decrease in the amount of residual timor. However, these preliminary results indicate that also an additional amount of normal brain is resected, which will be further investigated.

Development of a Hybrid Atomic Force Microscopic Measurement System Combined with White Light Scanning Interferometry

PubMed Central

Guo, Tong; Wang, Siming; Dorantes-Gonzalez, Dante J.; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2012-01-01

A hybrid atomic force microscopic (AFM) measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system’s dynamic response, the frequency modulation (FM) mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system’s good measurement performance and feasibility of the hybrid measurement method. PMID:22368463

Development of a hybrid atomic force microscopic measurement system combined with white light scanning interferometry.

PubMed

Guo, Tong; Wang, Siming; Dorantes-Gonzalez, Dante J; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2012-01-01

A hybrid atomic force microscopic (AFM) measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system's dynamic response, the frequency modulation (FM) mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system's good measurement performance and feasibility of the hybrid measurement method.

The e-evolution of microscopy in dental education.

PubMed

Farah, Camile S; Maybury, Terrence S

2009-08-01

Recent technological innovation has now made it possible to turn the computer into a microscope. This has entailed a shift from light microscopy to virtual microscopy. This development then foregrounds the issue of the pedagogy involved in this move from the analogue technology of the light microscope to the digital, computerized instance of virtual microscopy. In order to address this issue, undergraduate students enrolled in the Bachelor of Dental Science program at the University of Queensland School of Dentistry were surveyed to ascertain their preference for light or virtual microscopy. The value of this study is that it was conducted on the same cohort of students in two separate courses in 2006 and 2008, giving it longitudinal validity. The responses were overwhelmingly in favor of virtual microscopy. When it came to completely replacing the light microscope with virtual microscopy, however, students were much more ambivalent about such a wholesale change although this was less of an issue in the senior year. This shift from light to virtual microscopy signals larger changes in the tertiary sector from print-literate to electronic forms of knowledge and from teacher-centered to student-focused frames of learning. In short, we are in the midst of the e-evolution of microscopy in dental education.

Contrast and decay of cathodoluminescence from phosphor particles in a scanning electron microscope.

PubMed

den Engelsen, Daniel; Harris, Paul G; Ireland, Terry G; Fern, George R; Silver, Jack

2015-10-01

Cathodoluminescence (CL) studies are reported on phosphors in a field emission scanning electron microscope (FESEM). ZnO: Zn and other luminescent powders manifest a bright ring around the periphery of the particles: this ring enhances the contrast. Additionally, particles resting on top of others are substantially brighter than underlying ones. These phenomena are explained in terms of the combined effects of electrons backscattered out of the particles, together with light absorption by the substrate. The contrast is found to be a function of the particle size and the energy of the primary electrons. Some phosphor materials exhibit a pronounced comet-like structure at high scan rates in a CL-image, because the particle continues to emit light after the electron beam has moved to a position without phosphor material. Image analysis has been used to study the loss of brightness along the tail and hence to determine the decay time of the materials. The effect of phosphor saturation on the determination of decay times by CL-microscopy was also investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

Sleep Deprivation Alters Rat Ventral Prostate Morphology, Leading to Glandular Atrophy: A Microscopic Study Contrasted with the Hormonal Assays

PubMed Central

Venâncio, Daniel P.; Andersen, Monica L.; Vilamaior, Patricia S. L.; Santos, Fernanda C.; Zager, Adriano; Tufik, Sérgio; Taboga, Sebastião R.; De Mello, Marco T.

2012-01-01

We investigated the effect of 96 h paradoxical sleep deprivation (PSD) and 21-day sleep restriction (SR) on prostate morphology using stereological assays in male rats. After euthanasia, the rat ventral prostate was removed, weighed, and prepared for conventional light microscopy. Microscopic analysis of the prostate reveals that morphology of this gland was altered after 96 h of PSD and 21 days of SR, with the most important alterations occurring in the epithelium and stroma in the course of both procedures compared with the control group. Both 96 h PSD and 21-day SR rats showed lower serum testosterone and higher corticosterone levels than control rats. The significance of our result referring to the sleep deprivation was responsible for deep morphological alterations in ventral prostate tissue, like to castration microscopic modifications. This result is due to the marked alterations in hormonal status caused by PSD and SR. PMID:22927719

Microstructure Evolution and Mechanical Properties of Mg-14%Li-1%Al Alloy During the High-Pressure Torsion

NASA Astrophysics Data System (ADS)

Tian, Chenguang; Lu, Huimin; Zhao, Liyuan

The super-light LA141 (Mg-14%Li-1%Al) alloy was produced and processed by high-pressure torsion (HPT) under the imposed pressure of 3 GPa and different shear strains γ through 3, 6, 9 and 12 turns at room temperature (RT). The microstructure evolution of the alloy during the HPT treatment was investigated by transmission electron microscope (TEM) and optical microscope (OM). It turned out that the grains were substantially refined, and the optical microscope revealed that the grains of HPT processed samples at the edge of the disc were finer by comparison with the ones near the center of the disc. Later, Vickers indentation analysis was used to evaluate the micro-hardness of deformed samples, and tension test was employed to obtain the strength and elongation at room temperature. The results indicated that the micro-hardness and tensile strength had increased to a certain extent, and the elongation had been significantly improved.

A high-throughput screening system for barley/powdery mildew interactions based on automated analysis of light micrographs.

PubMed

Ihlow, Alexander; Schweizer, Patrick; Seiffert, Udo

2008-01-23

To find candidate genes that potentially influence the susceptibility or resistance of crop plants to powdery mildew fungi, an assay system based on transient-induced gene silencing (TIGS) as well as transient over-expression in single epidermal cells of barley has been developed. However, this system relies on quantitative microscopic analysis of the barley/powdery mildew interaction and will only become a high-throughput tool of phenomics upon automation of the most time-consuming steps. We have developed a high-throughput screening system based on a motorized microscope which evaluates the specimens fully automatically. A large-scale double-blind verification of the system showed an excellent agreement of manual and automated analysis and proved the system to work dependably. Furthermore, in a series of bombardment experiments an RNAi construct targeting the Mlo gene was included, which is expected to phenocopy resistance mediated by recessive loss-of-function alleles such as mlo5. In most cases, the automated analysis system recorded a shift towards resistance upon RNAi of Mlo, thus providing proof of concept for its usefulness in detecting gene-target effects. Besides saving labor and enabling a screening of thousands of candidate genes, this system offers continuous operation of expensive laboratory equipment and provides a less subjective analysis as well as a complete and enduring documentation of the experimental raw data in terms of digital images. In general, it proves the concept of enabling available microscope hardware to handle challenging screening tasks fully automatically.

Direction-division multiplexed holographic free-electron-driven light sources

NASA Astrophysics Data System (ADS)

Clarke, Brendan P.; MacDonald, Kevin F.; Zheludev, Nikolay I.

2018-01-01

We report on a free-electron-driven light source with a controllable direction of emission. The source comprises a microscopic array of plasmonic surface-relief holographic domains, each tailored to direct electron-induced light emission at a selected wavelength into a collimated beam in a prescribed direction. The direction-division multiplexed source is tested by driving it with the 30 kV electron beam of a scanning electron microscope: light emission, at a wavelength of 800 nm in the present case, is switched among different output angles by micron-scale repositioning of the electron injection point among domains. Such sources, with directional switching/tuning possible at picosecond timescales, may be applied to field-emission and surface-conduction electron-emission display technologies, optical multiplexing, and charged-particle-beam position metrology.

Enhanced optical coupling and Raman scattering via microscopic interface engineering

NASA Astrophysics Data System (ADS)

Thompson, Jonathan V.; Hokr, Brett H.; Kim, Wihan; Ballmann, Charles W.; Applegate, Brian E.; Jo, Javier A.; Yamilov, Alexey; Cao, Hui; Scully, Marlan O.; Yakovlev, Vladislav V.

2017-11-01

Spontaneous Raman scattering is an extremely powerful tool for the remote detection and identification of various chemical materials. However, when those materials are contained within strongly scattering or turbid media, as is the case in many biological and security related systems, the sensitivity and range of Raman signal generation and detection is severely limited. Here, we demonstrate that through microscopic engineering of the optical interface, the optical coupling of light into a turbid material can be substantially enhanced. This improved coupling facilitates the enhancement of the Raman scattering signal generated by molecules within the medium. In particular, we detect at least two-orders of magnitude more spontaneous Raman scattering from a sample when the pump laser light is focused into a microscopic hole in the surface of the sample. Because this approach enhances both the interaction time and interaction region of the laser light within the material, its use will greatly improve the range and sensitivity of many spectroscopic techniques, including Raman scattering and fluorescence emission detection, inside highly scattering environments.

Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.

PubMed

Sabel, Nina; Klingberg, Gunilla; Dietz, Wolfram; Nietzsche, Sandor; Norén, Jörgen G

2010-01-01

Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia. To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy. Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope. The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous. Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.

A clinical pathologic study of mercurialentis medicamentosus.

PubMed

Garron, L K; Wood, I S; Spencer, W H; Hayes, T L

1976-01-01

Thirty-one patients who used eye drops containing the preservative, phenylmercuric nitrate for from 3 to 15 years, developed a brownish pigmentation of the anterior capsule of the pupillary area. Light and electron microscopic studies on two lenses demonstrated deposits of dense particulate material resembling melanin pigment on and in the anterior capsule of the lens in the area of the pupil. Special studies, including electron microprobe analysis and neutron activation analysis established the presence of mercury in a lens with mercurialentis. No mercury was found in two lenses used as controls.

Amplitude analysis and the nature of the Z c(3900)

DOE PAGES

Pilloni, A.; Fernandez-Ramirez, C.; Jackura, A.; ...

2017-06-21

The microscopic nature of the XYZ states remains an unsettled topic. We show how a thorough amplitude analysis of the data can help constraining models of these states. Specifically, we consider the case of the Z c(3900) peak and discuss possible scenarios of a QCD state, virtual state, or a kinematical enhancement. Here, we conclude that current data are not precise enough to distinguish between these hypotheses, however, the method we propose, when applied to the forthcoming high-statistics measurements should shed light on the nature of these exotic enhancements.

Amplitude analysis and the nature of the Z c(3900)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilloni, A.; Fernandez-Ramirez, C.; Jackura, A.

The microscopic nature of the XYZ states remains an unsettled topic. We show how a thorough amplitude analysis of the data can help constraining models of these states. Specifically, we consider the case of the Z c(3900) peak and discuss possible scenarios of a QCD state, virtual state, or a kinematical enhancement. Here, we conclude that current data are not precise enough to distinguish between these hypotheses, however, the method we propose, when applied to the forthcoming high-statistics measurements should shed light on the nature of these exotic enhancements.

Determining the phonon energy of highly oriented pyrolytic graphite by scanning tunneling microscope light emission spectroscopy

NASA Astrophysics Data System (ADS)

Uehara, Yoichi; Michimata, Junichi; Watanabe, Shota; Katano, Satoshi; Inaoka, Takeshi

2018-03-01

We have investigated the scanning tunneling microscope (STM) light emission spectra of isolated single Ag nanoparticles lying on highly oriented pyrolytic graphite (HOPG). The STM light emission spectra exhibited two types of spectral structures (step-like and periodic). Comparisons of the observed structures and theoretical predictions indicate that the phonon energy of the ZO mode of HOPG [M. Mohr et al., Phys. Rev. B 76, 035439 (2007)] can be determined from the energy difference between the cutoff of STM light emission and the step in the former structure, and from the period of the latter structure. Since the role of the Ag nanoparticles does not depend on the substrate materials, this method will enable the phonon energies of various materials to be measured by STM light emission spectroscopy. The spatial resolution is comparable to the lateral size of the individual Ag nanoparticles (that is, a few nm).

Plasmon-resonance-enhanced visible-light photocatalytic activity of Ag quantum dots/TiO2 microspheres for methyl orange degradation

NASA Astrophysics Data System (ADS)

Yu, Xin; Shang, Liwei; Wang, Dongjun; An, Li; Li, Zhonghua; Liu, Jiawen; Shen, Jun

2018-06-01

We successfully prepared Ag quantum dots modified TiO2 microspheres by facile solvothermal and calcination method. The as-prepared Ag quantum dots/TiO2 microspheres were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The Ag quantum dots/TiO2 photocatalyst showed excellent visible light absorption and efficient photocatalytic activity for methyl orange degradation. And the sample with the molar ratio of 0.05 (Ag to Ti) showed the best visible light photocatalytic activity for methyl orange degradation, mainly because of the surface plasmon resonance (SPR) effects of Ag quantum dots to generate electron and hole pairs for enhanced visible light photocatalysis. Finally, possible visible light photocatalytic mechanism of Ag quantum dots/TiO2 microspheres for methyl orange degradation was proposed in detail.

Nonlinear photomechanics of nematic networks: upscaling microscopic behaviour to macroscopic deformation

NASA Astrophysics Data System (ADS)

Chung, Hayoung; Choi, Joonmyung; Yun, Jung-Hoon; Cho, Maenghyo

2016-02-01

A liquid crystal network whose chromophores are functionalized by photochromic dye exhibits light-induced mechanical behaviour. As a result, the micro-scaled thermotropic traits of the network and the macroscopic phase behaviour are both influenced as light alternates the shape of the dyes. In this paper, we present an analysis of this photomechanical behaviour based on the proposed multiscale framework, which incorporates the molecular details of microstate evolution into a continuum-based understanding. The effects of trans-to-cis photoisomerization driven by actinic light irradiation are first examined using molecular dynamics simulations, and are compared against the predictions of the classical dilution model; this reveals certain characteristics of mesogenic interaction upon isomerization, followed by changes in the polymeric structure. We then upscale the thermotropic phase-related information with the aid of a nonlinear finite element analysis; macroscopic deflection with respect to the wide ranges of temperature and actinic light intensity are thereby examined, which reveals that the classical model underestimates the true deformation. This work therefore provides measures for analysing photomechanics in general by bridging the gap between the micro- and macro-scales.

Polarization Imaging Apparatus

NASA Technical Reports Server (NTRS)

Zou, Yingyin K.; Chen, Qiushui

2010-01-01

A polarization imaging apparatus has shown promise as a prototype of instruments for medical imaging with contrast greater than that achievable by use of non-polarized light. The underlying principles of design and operation are derived from observations that light interacts with tissue ultrastructures that affect reflectance, scattering, absorption, and polarization of light. The apparatus utilizes high-speed electro-optical components for generating light properties and acquiring polarization images through aligned polarizers. These components include phase retarders made of OptoCeramic (registered TradeMark) material - a ceramic that has a high electro-optical coefficient. The apparatus includes a computer running a program that implements a novel algorithm for controlling the phase retarders, capturing image data, and computing the Stokes polarization images. Potential applications include imaging of superficial cancers and other skin lesions, early detection of diseased cells, and microscopic analysis of tissues. The high imaging speed of this apparatus could be beneficial for observing live cells or tissues, and could enable rapid identification of moving targets in astronomy and national defense. The apparatus could also be used as an analysis tool in material research and industrial processing.

A simple apparatus for quick qualitative analysis of CR39 nuclear track detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gautier, D. C.; Kline, J. L.; Flippo, K. A.

2008-10-15

Quantifying the ion pits in Columbia Resin 39 (CR39) nuclear track detector from Thomson parabolas is a time consuming and tedious process using conventional microscope based techniques. A simple inventive apparatus for fast screening and qualitative analysis of CR39 detectors has been developed, enabling efficient selection of data for a more detailed analysis. The system consists simply of a green He-Ne laser and a high-resolution digital single-lens reflex camera. The laser illuminates the edge of the CR39 at grazing incidence and couples into the plastic, acting as a light pipe. Subsequently, the laser illuminates all ion tracks on the surface.more » A high-resolution digital camera is used to photograph the scattered light from the ion tracks, enabling one to quickly determine charge states and energies measured by the Thomson parabola.« less

3D widefield light microscope image reconstruction without dyes

NASA Astrophysics Data System (ADS)

Larkin, S.; Larson, J.; Holmes, C.; Vaicik, M.; Turturro, M.; Jurkevich, A.; Sinha, S.; Ezashi, T.; Papavasiliou, G.; Brey, E.; Holmes, T.

2015-03-01

3D image reconstruction using light microscope modalities without exogenous contrast agents is proposed and investigated as an approach to produce 3D images of biological samples for live imaging applications. Multimodality and multispectral imaging, used in concert with this 3D optical sectioning approach is also proposed as a way to further produce contrast that could be specific to components in the sample. The methods avoid usage of contrast agents. Contrast agents, such as fluorescent or absorbing dyes, can be toxic to cells or alter cell behavior. Current modes of producing 3D image sets from a light microscope, such as 3D deconvolution algorithms and confocal microscopy generally require contrast agents. Zernike phase contrast (ZPC), transmitted light brightfield (TLB), darkfield microscopy and others can produce contrast without dyes. Some of these modalities have not previously benefitted from 3D image reconstruction algorithms, however. The 3D image reconstruction algorithm is based on an underlying physical model of scattering potential, expressed as the sample's 3D absorption and phase quantities. The algorithm is based upon optimizing an objective function - the I-divergence - while solving for the 3D absorption and phase quantities. Unlike typical deconvolution algorithms, each microscope modality, such as ZPC or TLB, produces two output image sets instead of one. Contrast in the displayed image and 3D renderings is further enabled by treating the multispectral/multimodal data as a feature set in a mathematical formulation that uses the principal component method of statistics.

Virtual Microscopy: A Useful Tool for Meeting Evolving Challenges in the Veterinary Medical Curriculum

NASA Astrophysics Data System (ADS)

Kogan, Lori R.; Dowers, Kristy L.; Cerda, Jacey R.; Schoenfeld-Tacher, Regina M.; Stewart, Sherry M.

2014-12-01

Veterinary schools, similar to many professional health programs, face a myriad of evolving challenges in delivering their professional curricula including expansion of class size, costs to maintain expensive laboratories, and increased demands on veterinary educators to use curricular time efficiently and creatively. Additionally, exponential expansion of the knowledge base through ongoing biomedical research, educational goals to increase student engagement and clinical reasoning earlier in the curriculum, and students' desire to access course materials and enhance their educational experience through the use of technology all support the need to reassess traditional microscope laboratories within Professional Veterinary Medical (PVM) educational programs. While there is clear justification for teaching veterinary students how to use a microscope for clinical evaluation of cytological preparations (i.e., complete blood count, urinalysis, fecal analysis, fine needle aspirates, etc.), virtual microscopy may be a viable alternative to using light microscopy for teaching and learning fundamental histological concepts. This article discusses results of a survey given to assess Professional Veterinary Medical students' perceptions of using virtual microscope for learning basic histology/microscopic anatomy and implications of these results for using virtual microscopy as a pedagogical tool in teaching first-year Professional Veterinary Medical students' basic histology.

Green tea extract induces protective autophagy in A549 non-small lung cancer cell line.

PubMed

Izdebska, Magdalena; Klimaszewska-Wiśniewska, Anna; Hałas, Marta; Gagat, Maciej; Grzanka, Alina

2015-12-31

For many decades, polyphenols, including green tea extract catechins, have been reported to exert multiple anti-tumor activities. However, to date the mechanisms of their action have not been completely elucidated. Thus, the aim of this study was to assess the effect of green tea extract on non-small lung cancer A549 cells. A549 cells following treatment with GTE were analyzed using the inverted light and fluorescence microscope. In order to evaluate cell sensitivity and cell death, the MTT assay and Tali image-based cytometer were used, respectively. Ultrastructural alterations were assessed using a transmission electron microscope. The obtained data suggested that GTE, even at the highest dose employed (150 μM), was not toxic to A549 cells. Likewise, the treatment with GTE resulted in only a very small dose-dependent increase in the population of apoptotic cells. However, enhanced accumulation of vacuole-like structures in response to GTE was seen at the light and electron microscopic level. Furthermore, an increase in the acidic vesicular organelles and LC3-II puncta formation was observed under the fluorescence microscope, following GTE treatment. The analysis of the functional status of autophagy revealed that GTE-induced autophagy may provide self-protection against its own cytotoxicity, since we observed that the blockage of autophagy by bafilomycin A1 decreased the viability of A549 cells and potentiated necrotic cell death induction in response to GTE treatment. Collectively, our results revealed that A549 cells are insensitive to both low and high concentrations of the green tea extract, probably due to the induction of cytoprotective autophagy. These data suggest that a potential utility of GTE in lung cancer therapy may lie in its synergistic combinations with drugs or small molecules that target autophagy, rather than in monotherapy.

Increasing Student Understanding of Microscope Optics by Building and Testing the Limits of Simple, Hand-Made Model Microscopes†

PubMed Central

Drace, Kevin; Couch, Brett; Keeling, Patrick J.

2012-01-01

The ability to effectively use a microscope to observe microorganisms is a crucial skill required for many disciplines within biology, especially general microbiology and cell biology. A basic understanding of the optical properties of light microscopes is required for students to use microscopes effectively, but this subject can also be a challenge to make personally interesting to students. To explore basic optical principles of magnification and resolving power in a more engaging and hands-on fashion, students constructed handmade lenses and microscopes based on Antony van Leeuwenhoek’s design using simple materials—paper, staples, glass, and adhesive putty. Students determined the power of their lenses using a green laser pointer to magnify a copper grid of known size, which also allowed students to examine variables affecting the power and resolution of a lens such as diameter, working distance, and wavelength of light. To assess the effectiveness of the laboratory’s learning objectives, four sections of a general microbiology course were given a brief pre-activity assessment quiz to determine their background knowledge on the subject. One week after the laboratory activity, students were given the same quiz (unannounced) under similar conditions. Students showed significant gains in their understanding of microscope optics. PMID:23653781

Localization of nitric oxide synthase and NADPH-diaphorase in guinea pig and human cochleae.

PubMed

Ruan, R S; Leong, S K; Yeoh, K H

1997-01-01

The distributions of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and nitric oxide synthase (NOS) in mammalian cochlea were studied at light and electron microscope levels by NADPH-d histochemistry and brain NOS (bNOS) immunohistochemistry. The cochleae from 15 albino guinea pigs were perilymphatically fixed with 2% periodate-lysine-paraformaldehyde, decalcified in 10% EDTA and processed for light and electron microscopy after NADPH-d or NOS staining in frozen and vibratome sections respectively. One human cochlea was available for light microscope examination of NADPH-d or bNOS stained sections. Light microscope results revealed that type I neurons and nerve fibers of the spiral ganglion cells were labeled by bNOS immunohistochemistry as well as NADPH-d histochemistry in both guinea pig and human cochleae. At subcellular level, NADPH-d reaction product was localized in the mitochondria of the neuronal cytoplasm and axoplasm and in the cytoplasm of the vascular endothelium. The immunoreaction products of bNOS were evenly distributed in the neuronal cytoplasm and axoplasm. Myelinated and unmyelinated fibers in the intraganglionic spiral bundle and the inner spiral and inner radial fibers below the inner hair cells were labeled for bNOS. The nerve endings below the outer hair cells were not stained. NOS immunoreaction product was also found in the outer hair cells, Schwann cells of myelinated nerve fibers, Deiter's cells, pillar cells and the tympanic lamina cells. No difference was found in the staining pattern of both NADPH-d and NOS reaction products between human and guinea pig cochleae at the light microscope level. The results suggest that NO plays an important role in the maintenance of auditory function in the mammal.

Hyperspectral microscopy to identify foodborne bacteria with optimum lighting source

USDA-ARS?s Scientific Manuscript database

Hyperspectral microscopy is an emerging technology for rapid detection of foodborne pathogenic bacteria. Since scattering spectral signatures from hyperspectral microscopic images (HMI) vary with lighting sources, it is important to select optimal lights. The objective of this study is to compare t...

Sub-25-nm laboratory x-ray microscopy using a compound Fresnel zone plate.

PubMed

von Hofsten, Olov; Bertilson, Michael; Reinspach, Julia; Holmberg, Anders; Hertz, Hans M; Vogt, Ulrich

2009-09-01

Improving the resolution in x-ray microscopes is of high priority to enable future applications in nanoscience. However, high-resolution zone-plate optics often have low efficiency, which makes implementation in laboratory microscopes difficult. We present a laboratory x-ray microscope based on a compound zone plate. The compound zone plate utilizes multiple diffraction orders to achieve high resolution while maintaining reasonable efficiency. We analyze the illumination conditions necessary for this type of optics in order to suppress stray light and demonstrate microscopic imaging resolving 25 nm features.

A simple water-immersion condenser for imaging living brain slices on an inverted microscope.

PubMed

Prusky, G T

1997-09-05

Due to some physical limitations of conventional condensers, inverted compound microscopes are not optimally suited for imaging living brain slices with transmitted light. Herein is described a simple device that converts an inverted microscope into an effective tool for this application by utilizing an objective as a condenser. The device is mounted on a microscope in place of the condenser, is threaded to accept a water immersion objective, and has a slot for a differential interference contrast (DIC) slider. When combined with infrared video techniques, this device allows an inverted microscope to effectively image living cells within thick brain slices in an open perfusion chamber.

Analysis of spectral light guidance in specialty fibers

NASA Astrophysics Data System (ADS)

Zimmer, Arne W.; Raithel, Philipp; Belz, Mathias; Klein, Karl-Friedrich

2016-04-01

A novel experimental set-up for measuring the spectral dependency of light-guidance of specialty non-active multimodefibers will be introduced. Light coupling into the test fiber is realized and controlled with a micro-structured single mode (SM) fiber and an image-system based on a microscope objective The far- and near-field profiles of the SM-fiber will be shown. The inverse far field method is modified and improved by using three wavelengths simultaneously under the same input conditions; the coupling conditions into the test-fiber and the far- and near-field at fiber output are observed with cameras. The numerical aperture (NA) and mode-conversion or focal-ratio-degradation (FRD) are measured in respect to wavelength at three wavelengths in the VIS region. For the analysis, the patterns are captured at varying exposure times to increase the dynamic range and finally analyzed using image processing methods. Characteristic parameters, such as skew mode propagation and ray-conversion, of circular and non-circular MM-fibers will be discussed, taking the surface roughness into account.

Improved resolution in practical light microscopy by means of a glass-fiber 2 π-tilting device

NASA Astrophysics Data System (ADS)

Bradl, Joachim; Rinke, Bernd; Schneider, Bernhard; Hausmann, Michael; Cremer, Christoph G.

1996-01-01

The spatial resolution of a conventional light microscope or a confocal laser scanning microscope can be determined by calculating the point spread function for the objective used. Normally, ideal conditions are assumed for these calculations. Such conditions, however, are often not fulfilled in biological applications especially in those cases where biochemical requirements (e.g. buffer conditions) influence the specimen preparation on the microscope slide (i.e. 'practical' light microscopy). It has been shown that the problem of a reduced z- resolution in 3D-microscopy (optical sectioning) can be overcome by a capillary in a 2(pi) - tilting device that allows object rotation into an optimal perspective. The application of the glass capillary instead of a standard slide has an additional influence on the imaging properties of the microscope. Therefore, another 2(pi) -tilting device was developed, using a glass fiber for object fixation and rotation. Such a fiber could be covered by standard cover glasses. To estimate the resolution of this setup, point spread functions were measured under different conditions using fluorescent microspheres of subwavelength dimensions. Results obtained from standard slide setups were compared to the glass fiber setup. These results showed that in practice rotation leads to an overall 3D-resolution improvement.

RGB digital lensless holographic microscopy

NASA Astrophysics Data System (ADS)

Garcia-Sucerquia, Jorge

2013-11-01

The recent introduction of color digital lensless holographic microscopy (CDLHM) has shown the possibility of imaging microscopic specimens at full color without the need of lenses. Owing to the simplicity, robustness, and compactness of the digital lensless holographic microscopes (DLHM), they have been presented as the ideal candidates to being developed into portable holographic microscopes. However, in the case of CDLHM the utilization of three independent lasers hinders the portability option for this microscope. In this contribution an alternative to reduce the complexity of CDLHM aimed to recover the portability of this microscopy technology is presented. A super-bright white-light light-emitting diode (LED) is spectrally and spatially filtered to produce the needed illumination by CDLHM to work. CDLHM with LED illumination is used to image at full color a section of the head of a drosophila melanogaster fly (fruit fly). The LED-CDLHM method shows the capability of imaging objects of 2μm size in comparison with the micrometer resolution reported for LASER-CDLHM.

Optical forces, torques, and force densities calculated at a microscopic level using a self-consistent hydrodynamics method

NASA Astrophysics Data System (ADS)

Ding, Kun; Chan, C. T.

2018-04-01

The calculation of optical force density distribution inside a material is challenging at the nanoscale, where quantum and nonlocal effects emerge and macroscopic parameters such as permittivity become ill-defined. We demonstrate that the microscopic optical force density of nanoplasmonic systems can be defined and calculated using the microscopic fields generated using a self-consistent hydrodynamics model that includes quantum, nonlocal, and retardation effects. We demonstrate this technique by calculating the microscopic optical force density distributions and the optical binding force induced by external light on nanoplasmonic dimers. This approach works even in the limit when the nanoparticles are close enough to each other so that electron tunneling occurs, a regime in which classical electromagnetic approach fails completely. We discover that an uneven distribution of optical force density can lead to a light-induced spinning torque acting on individual particles. The hydrodynamics method offers us an accurate and efficient approach to study optomechanical behavior for plasmonic systems at the nanoscale.

Light Microscopy's New Jobs

NASA Astrophysics Data System (ADS)

Ritsch-Marte, Monika

2009-04-01

300 years since the first glimpse through the earliest microscopes, light microscopy is still an active field of research, breaking new frontiers in optical imaging and even becoming a means of mechanical manipulation of microparticles.

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

PubMed

Paddock, Stephen W; Eliceiri, Kevin W

2014-01-01

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

Optical sectioning microscopes with no moving parts using a micro-stripe array light emitting diode.

PubMed

Poher, V; Zhang, H X; Kennedy, G T; Griffin, C; Oddos, S; Gu, E; Elson, D S; Girkin, M; French, P M W; Dawson, M D; Neil, M A

2007-09-03

We describe an optical sectioning microscopy system with no moving parts based on a micro-structured stripe-array light emitting diode (LED). By projecting arbitrary line or grid patterns onto the object, we are able to implement a variety of optical sectioning microscopy techniques such as grid-projection structured illumination and line scanning confocal microscopy, switching from one imaging technique to another without modifying the microscope setup. The micro-structured LED and driver are detailed and depth discrimination capabilities are measured and calculated.

Studies of mechanisms of decay and recovery in organic dye-doped polymers using spatially resolved white light interferometry

NASA Astrophysics Data System (ADS)

Anderson, Benjamin; Bernhardt, Elizabeth; Kuzyk, Mark

2012-10-01

Several organic dyes have been shown to self heal when doped in a polymer matrix. Most measurements to date use optical absorbance, amplified spontaneous emission, or digital imaging as a probe. Each method determines a subset of the relevant parameters. We have constructed a white light interferometric microscope, which measures the absorption spectrum and change in refractive index during decay and recovery simultaneously at multiple points in the material. We report on preliminary measurements and results concerning the microscopes spatial resolution.

Electroluminescence of a polythiophene molecular wire suspended between a metallic surface and the tip of a scanning tunneling microscope.

PubMed

Reecht, Gaël; Scheurer, Fabrice; Speisser, Virginie; Dappe, Yannick J; Mathevet, Fabrice; Schull, Guillaume

2014-01-31

The electroluminescence of a polythiophene wire suspended between a metallic surface and the tip of a scanning tunneling microscope is reported. Under positive sample voltage, the spectral and voltage dependencies of the emitted light are consistent with the fluorescence of the wire junction mediated by localized plasmons. This emission is strongly attenuated for the opposite polarity. Both emission mechanism and polarity dependence are similar to what occurs in organic light emitting diodes (OLED) but at the level of a single molecular wire.

Camera array based light field microscopy

PubMed Central

Lin, Xing; Wu, Jiamin; Zheng, Guoan; Dai, Qionghai

2015-01-01

This paper proposes a novel approach for high-resolution light field microscopy imaging by using a camera array. In this approach, we apply a two-stage relay system for expanding the aperture plane of the microscope into the size of an imaging lens array, and utilize a sensor array for acquiring different sub-apertures images formed by corresponding imaging lenses. By combining the rectified and synchronized images from 5 × 5 viewpoints with our prototype system, we successfully recovered color light field videos for various fast-moving microscopic specimens with a spatial resolution of 0.79 megapixels at 30 frames per second, corresponding to an unprecedented data throughput of 562.5 MB/s for light field microscopy. We also demonstrated the use of the reported platform for different applications, including post-capture refocusing, phase reconstruction, 3D imaging, and optical metrology. PMID:26417490

A line scanned light-sheet microscope with phase shaped self-reconstructing beams.

PubMed

Fahrbach, Florian O; Rohrbach, Alexander

2010-11-08

We recently demonstrated that Microscopy with Self-Reconstructing Beams (MISERB) increases both image quality and penetration depth of illumination beams in strongly scattering media. Based on the concept of line scanned light-sheet microscopy, we present an add-on module to a standard inverted microscope using a scanned beam that is shaped in phase and amplitude by a spatial light modulator. We explain technical details of the setup as well as of the holograms for the creation, positioning and scaling of static light-sheets, Gaussian beams and Bessel beams. The comparison of images from identical sample areas illuminated by different beams allows a precise assessment of the interconnection between beam shape and image quality. The superior propagation ability of Bessel beams through inhomogeneous media is demonstrated by measurements on various scattering media.

Single particle tracking through highly scattering media with multiplexed two-photon excitation

NASA Astrophysics Data System (ADS)

Perillo, Evan; Liu, Yen-Liang; Liu, Cong; Yeh, Hsin-Chih; Dunn, Andrew K.

2015-03-01

3D single-particle tracking (SPT) has been a pivotal tool to furthering our understanding of dynamic cellular processes in complex biological systems, with a molecular localization accuracy (10-100 nm) often better than the diffraction limit of light. However, current SPT techniques utilize either CCDs or a confocal detection scheme which not only suffer from poor temporal resolution but also limit tracking to a depth less than one scattering mean free path in the sample (typically <15μm). In this report we highlight our novel design for a spatiotemporally multiplexed two-photon microscope which is able to reach sub-diffraction-limit tracking accuracy and sub-millisecond temporal resolution, but with a dramatically extended SPT range of up to 200 μm through dense cell samples. We have validated our microscope by tracking (1) fluorescent nanoparticles in a prescribed motion inside gelatin gel (with 1% intralipid) and (2) labeled single EGFR complexes inside skin cancer spheroids (at least 8 layers of cells thick) for ~10 minutes. Furthermore we discuss future capabilities of our multiplexed two-photon microscope design, specifically to the extension of (1) simultaneous multicolor tracking (i.e. spatiotemporal co-localization analysis) and (2) FRET studies (i.e. lifetime analysis). The high resolution, high depth penetration, and multicolor features of this microscope make it well poised to study a variety of molecular scale dynamics in the cell, especially related to cellular trafficking studies with in vitro tumor models and in vivo.

A Comparative Study of Microscopic Images Captured by a Box Type Digital Camera Versus a Standard Microscopic Photography Camera Unit

PubMed Central

Desai, Nandini J.; Gupta, B. D.; Patel, Pratik Narendrabhai

2014-01-01

Introduction: Obtaining images of slides viewed by a microscope can be invaluable for both diagnosis and teaching.They can be transferred among technologically-advanced hospitals for further consultation and evaluation. But a standard microscopic photography camera unit (MPCU)(MIPS-Microscopic Image projection System) is costly and not available in resource poor settings. The aim of our endeavour was to find a comparable and cheaper alternative method for photomicrography. Materials and Methods: We used a NIKON Coolpix S6150 camera (box type digital camera) with Olympus CH20i microscope and a fluorescent microscope for the purpose of this study. Results: We got comparable results for capturing images of light microscopy, but the results were not as satisfactory for fluorescent microscopy. Conclusion: A box type digital camera is a comparable, less expensive and convenient alternative to microscopic photography camera unit. PMID:25478350

Five years of experience teaching pathology to dental students using the WebMicroscope

PubMed Central

2011-01-01

Background We describe development and evaluation of the user-friendly web based virtual microscopy - WebMicroscope for teaching and learning dental students basic and oral pathology. Traditional students microscopes were replaced by computer workstations. Methods The transition of the basic and oral pathology courses from light to virtual microscopy has been completed gradually over a five-year period. A pilot study was conducted in academic year 2005/2006 to estimate the feasibility of integrating virtual microscopy into a traditional light microscopy-based pathology course. The entire training set of glass slides was subsequently converted to virtual slides and placed on the WebMicroscope server. Giving access to fully digitized slides on the web with a browser and a viewer plug-in, the computer has become a perfect companion of the student. Results The study material consists now of over 400 fully digitized slides which covering 15 entities in basic and systemic pathology and 15 entities in oral pathology. Digitized slides are linked with still macro- and microscopic images, organized with clinical information into virtual cases and supplemented with text files, syllabus, PowerPoint presentations and animations on the web, serving additionally as material for individual studies. After their examinations, the students rated the use of the software, quality of the images, the ease of handling the images, and the effective use of virtual slides during the laboratory practicals. Responses were evaluated on a standardized scale. Because of the positive opinions and support from the students, the satisfaction surveys had shown a progressive improvement over the past 5 years. The WebMicroscope as a didactic tool for laboratory practicals was rated over 8 on a 1-10 scale for basic and systemic pathology and 9/10 for oral pathology especially as various students’ suggestions were implemented. Overall, the quality of the images was rated as very good. Conclusions An overwhelming majority of our students regarded a possibility of using virtual slides at their convenience as highly desirable. Our students and faculty consider the use of the virtual microscope for the study of basic as well as oral pathology as a significant improvement over the light microscope. PMID:21489183

A method for fast automated microscope image stitching.

PubMed

Yang, Fan; Deng, Zhen-Sheng; Fan, Qiu-Hong

2013-05-01

Image stitching is an important technology to produce a panorama or larger image by combining several images with overlapped areas. In many biomedical researches, image stitching is highly desirable to acquire a panoramic image which represents large areas of certain structures or whole sections, while retaining microscopic resolution. In this study, we develop a fast normal light microscope image stitching algorithm based on feature extraction. At first, an algorithm of scale-space reconstruction of speeded-up robust features (SURF) was proposed to extract features from the images to be stitched with a short time and higher repeatability. Then, the histogram equalization (HE) method was employed to preprocess the images to enhance their contrast for extracting more features. Thirdly, the rough overlapping zones of the images preprocessed were calculated by phase correlation, and the improved SURF was used to extract the image features in the rough overlapping areas. Fourthly, the features were corresponded by matching algorithm and the transformation parameters were estimated, then the images were blended seamlessly. Finally, this procedure was applied to stitch normal light microscope images to verify its validity. Our experimental results demonstrate that the improved SURF algorithm is very robust to viewpoint, illumination, blur, rotation and zoom of the images and our method is able to stitch microscope images automatically with high precision and high speed. Also, the method proposed in this paper is applicable to registration and stitching of common images as well as stitching the microscope images in the field of virtual microscope for the purpose of observing, exchanging, saving, and establishing a database of microscope images. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diffraction-Unlimited Fluorescence Imaging with an EasySTED Retrofitted Confocal Microscope.

PubMed

Klauss, André; Hille, Carsten

2017-01-01

The easySTED technology provides the means to retrofit a confocal microscope to a diffraction-unlimited stimulated emission depletion (STED) microscope.Although commercial STED systems are available today, for many users of confocal laser scanning microscopes the option of retrofitting their confocal system to a STED system ready for diffraction-unlimited imaging may present an attractive option. The easySTED principle allowing for a joint beam path of excitation and depletion light promises some advantages concerning technical complexity and alignment effort for such an STED upgrade. In the one beam path design of easySTED the use of a common laser source, either a supercontinuum source or two separate lasers coupled into the same single-mode fiber, becomes feasible. The alignment of the focal light distribution of the STED beam relative to that of the excitation beam in all three spatial dimensions is therefore omitted respectively reduced to coupling the STED laser into the common single-mode fiber. Thus, only minor modifications need to be applied to the beam path in the confocal microscope to be upgraded. Those comprise adding polarization control elements and the easySTED waveplate, and adapting the beamsplitter to the excitation/STED wavelength combination.

Laser scanning confocal microscope with programmable amplitude, phase, and polarization of the illumination beam.

PubMed

Boruah, B R; Neil, M A A

2009-01-01

We describe the design and construction of a laser scanning confocal microscope with programmable beam forming optics. The amplitude, phase, and polarization of the laser beam used in the microscope can be controlled in real time with the help of a liquid crystal spatial light modulator, acting as a computer generated hologram, in conjunction with a polarizing beam splitter and two right angled prisms assembly. Two scan mirrors, comprising an on-axis fast moving scan mirror for line scanning and an off-axis slow moving scan mirror for frame scanning, configured in a way to minimize the movement of the scanned beam over the pupil plane of the microscope objective, form the XY scan unit. The confocal system, that incorporates the programmable beam forming unit and the scan unit, has been implemented to image in both reflected and fluorescence light from the specimen. Efficiency of the system to programmably generate custom defined vector beams has been demonstrated by generating a bottle structured focal volume, which in fact is the overlap of two cross polarized beams, that can simultaneously improve both the lateral and axial resolutions if used as the de-excitation beam in a stimulated emission depletion confocal microscope.

Quantification of Nanoscale Density Fluctuations in Biological Cells/Tissues: Inverse Participation Ratio (IPR) Analysis of Transmission Electron Microscopy Images and Implications for Early-Stage Cancer Detection

NASA Astrophysics Data System (ADS)

Pradhan, Prabhakar; Damania, Dhwanil; Joshi, Hrushikesh; Taflove, Allen; Roy, Hemant; Dravid, Vinayak; Backman, Vadim

2010-03-01

We report a study of the nanoscale mass density fluctuations of biological cells and tissues by quantifying their nanoscale light-localization properties. Transmission electron microscope (TEM) images of human cells and tissues are used to construct corresponding effective disordered optical lattices. Light-localization properties are studied by statistical analysis of the inverse participation ratio (IPR) of the eigenfunctions of these optical lattices at the nanoscales. Our results indicate elevation of the nanoscale disorder strength (e.g., refractive index fluctuations) in early carcinogenesis. Importantly, our results demonstrate that the increase in the nanoscale disorder represents the earliest structural alteration in cells undergoing carcinogenesis known to-date. Potential applications of the technique for early stage cancer detection will be discussed.

Correlative fractography: combining scanning electron microscopy and light microscopes for qualitative and quantitative analysis of fracture surfaces.

PubMed

Hein, Luis Rogerio de Oliveira; de Oliveira, José Alberto; de Campos, Kamila Amato

2013-04-01

Correlative fractography is a new expression proposed here to describe a new method for the association between scanning electron microscopy (SEM) and light microscopy (LM) for the qualitative and quantitative analysis of fracture surfaces. This article presents a new method involving the fusion of one elevation map obtained by extended depth from focus reconstruction from LM with exactly the same area by SEM and associated techniques, as X-ray mapping. The true topographic information is perfectly associated to local fracture mechanisms with this new technique, presented here as an alternative to stereo-pair reconstruction for the investigation of fractured components. The great advantage of this technique resides in the possibility of combining any imaging methods associated with LM and SEM for the same observed field from fracture surface.

Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

NASA Astrophysics Data System (ADS)

Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

2016-04-01

Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

ZnO nanoparticles based fiber optic gas sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narasimman, S.; Sivacoumar, R.; Alex, Z. C.

In this work, ZnO nanoparticles were synthesized by simple aqueous chemical route method. The synthesized ZnO nanoparticles were characterized by X-ray diffraction and scanning electron microscope. The sensitivity of the nanoparticles was studied for different gases like acetone, ammonia and ethanol in terms of variation in spectral light intensity. The XRD and SEM analysis confirms the formation of hexagonal wurtzite structure with the grain size of 11.2 nm. The small cladding region of the optical fiber was replaced with the synthesized nanoparticles. The light spectrum was recorded for different gas concentrations. The synthesized nanoparticles showed high sensitivity towards ammonia in lowmore » ppm level and acetone in high ppm level.« less

Polarized Light Corridor Demonstrations.

ERIC Educational Resources Information Center

Davies, G. R.

1990-01-01

Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

Role of Caspase-3 in acute light damage to retina of rats.

PubMed

Wang, Xiao; Hu, Shi-Xing; Li, Wei; Lin, Shao-Chun

2007-03-01

To investigate the role of Caspase-3 in retinal damage caused by light exposure in rats. Light injury to retina was induced by persistent exposure to illumination (intensity: 30 000 +/- 50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1, 3, 7, and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis. The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, especially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pigment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day. Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.

Scanning Microscopes Using X Rays and Microchannels

NASA Technical Reports Server (NTRS)

Wang, Yu

2003-01-01

Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the image sensor consists predominantly of radiation that was launched along the longitudinal direction of the microchannels. Therefore, most of the radiation arriving at each pixel on the sensor must have traveled along a straight line from a corresponding location on the specimen. Thus, there is a one-to-one mapping from a point on a specimen to a pixel in the image sensor, so that the output of the image sensor contains image information equivalent to that from a microscope.

Three-dimensional scanning confocal laser microscope

DOEpatents

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

1999-01-01

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.

Quantitative luminescence imaging system

DOEpatents

Erwin, David N.; Kiel, Johnathan L.; Batishko, Charles R.; Stahl, Kurt A.

1990-01-01

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.

The potential for early and rapid pathogen detection within poultry processing through hyperspectral microscopy

USDA-ARS?s Scientific Manuscript database

The acquisition of hyperspectral microscopic images containing both spatial and spectral data has shown potential for the early and rapid optical classification of foodborne pathogens. A hyperspectral microscope with a metal halide light source and acousto-optical tunable filter (AOTF) collects 89 ...

Integration of Histology Lectures and Practical Teaching in China

ERIC Educational Resources Information Center

Lu, Xiaoye; Cheng, Xin; Li, Ke; Lee, Kenneth Ka Ho; Yang, Xuesong

2016-01-01

Objectives: Human histology is a discipline concerning the study of microscopic structures of human tissues and organs--with the aid of light or electron microscopes. Traditional teaching of histology is composed of two separated components, theory and practice. The main disadvantage with traditional histology teaching is the detachment of theory…

Ultraviolet/visible photodiode of nanostructure Sn-doped ZnO/Si heterojunction

NASA Astrophysics Data System (ADS)

Kheirandish, N.; Mortezaali, A.

2013-05-01

Sn doped ZnO nanostructures deposited on Si substrate with (100) orientation by spray pyrolysis method at temperature 450 °C. Sn/Zn atomic ratio varies from 0% to 5%. The scanning electron microscope measurements showed that size of particles reduce with increasing the doping concentration. The X-ray diffraction analysis revealed formation of the wurtzite phase of ZnO. I-V curves of Sn doped ZnO/Si were investigated in dark and shows diode-like rectifying behavior. Among doped ZnO/Si, sample with atomic ratio of Sn/Zn = 5% is a good candidate to study photodiode properties in UV/visible range. Photoelectric effects have been observed under illumination monochromatic laser light with a wavelength of 325 nm and halogen lamp. Measurements demonstrate that the photodiode has high sensitivity and reproducibility to halogen light respect to laser light.

The method of segmentation of leukocytes in information-measuring systems on the basis of light microscopy

NASA Astrophysics Data System (ADS)

Nikitaev, V. G.; Pronichev, A. N.; Polyakov, E. V.; Zaharenko, Yu V.

2018-01-01

The paper considers the problem of leukocytes segmentation in microscopic images of bone marrow smears for automated diagnosis of the blood system diseases. The method was proposed to solve the problem of segmentation of contacting leukocytes in images of bone marrow smears. The method is based on the analysis of structure of objects of a separation and distances filter in combination with the watershed method and distance transformation method.

Formulation design and photochemical studies on nanocrystal solid dispersion of curcumin with improved oral bioavailability.

PubMed

Onoue, Satomi; Takahashi, Haruki; Kawabata, Yohei; Seto, Yoshiki; Hatanaka, Junya; Timmermann, Barbara; Yamada, Shizuo

2010-04-01

Considerable interest has been focused on curcumin due to its use to treat a wide variety of disorders, however, the therapeutic potential of curcumin could often be limited by its poor solubility, bioavailability, and photostability. To overcome these drawbacks, efficacious formulations of curcumin, including nanocrystal solid dispersion (CSD-Cur), amorphous solid dispersion (ASD-Cur), and nanoemulsion (NE-Cur), were designed with the aim of improving physicochemical and pharmacokinetic properties. Physicochemical properties of the prepared formulations were characterized by scanning/transmission electron microscope for morphological analysis, laser diffraction, and dynamic light scattering for particle size analysis, and polarized light microscope, powder X-ray diffraction and differential scanning calorimetry for crystallinity assessment. In dissolution tests, all curcumin formulations exhibited marked improvement in the dissolution behavior when compared with crystalline curcumin. Significant improvement in pharmacokinetic behavior was observed in the newly developed formulations, as evidenced by 12- (ASD-Cur), 16- (CSD-Cur), and 9-fold (NE-Cur) increase of oral bioavailability. Upon photochemical characterization, curcumin was found to be photoreactive and photodegradable in the solution state, possibly via type 2 photochemical reaction, whereas high photochemical stability was seen in the solid formulations, especially CSD-Cur. On the basis of these observations, taken together with dissolution and pharmacokinetic behaviors, CSD strategy would be efficacious to enhance bioavailability of curcumin with high photochemical stability. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

Screening and identification of proteins mediating senna induced gastrointestinal motility enhancement in mouse colon

PubMed Central

Wang, Xin; Zhong, Yue-Xia; Lan, Mei; Zhang, Zong-You; Shi, Yong-Quan; Lu, Ju; Ding, Jie; Wu, Kai-Cun; Jin, Jian-Ping; Pan, Bo-Rong; Fan, Dai Min

2002-01-01

AIM: To isolate the proteins involved in pharmacologic action of senna extract (SE) from mouse gastrointestinal tract and to explore the molecular mechanism of gastrointestinal motility change induced by SE. METHODS: SE was administrated to mice by different routes. Gastrointestinal motility of mice was observed using cathartic, gastrointestinal propellant movement experiments and X-ray analysis. Mouse model for gastrointestinal motility enhancement was established through continuous gastric administration of SE at progressively increased dose. At 3 h and week 3, 4, 6 and 10, morphological changes of gastrointestinal tissues were found under light microscope. Ultrastructural changes of intestinal and colonic tissues at week 6 were observed under transmission electron microscope. The colonic proteomic changes in model mice were examined by two-dimension polyacrylamide gel electrophoresis with immobilized pH gradient isoelectric focusing to screen the differentially expressed proteins, and their molecular masses and isoelectric points were determined. Two N-terminal sequences of the samples were also determined by mass spectrometry. RESULTS: SE (0.3 g) caused diarrhea after gastric administration in 1-6 h and enhanced gastrointestinal propellant (65.1% ± 7.5%; 45.8% ± 14.6%,P < 0.01) in mice, but intramuscular and hypodermic injection had no cathartic effect. X-ray analysis of gastrointestinal motility demonstrated that gastric administration of SE enhanced gastric evacuation and gastrointestinal transferring function. At 3 h and week 3 and 4 after gastric administration of SE, light microscopic examination revealed no apparent change in gastrointestinal mucosal tissues, but transmission electron microscopic examination revealed inflammatory changes in whole layer of intestinal and colonic wall. Twenty differential proteins were detected in the colonic tissues of the model mice by two-dimensional electrophoresis, and the N-terminal amino acid sequences of two proteins were determined. CONCLUSION: SE causes diarrhea and enhances gastrointestinal motility through digestive tract administration. Long-term gastric administration of SE induces inflammatory changes and cell damage in the whole gastrointestinal tract. The differential proteins screened from the colonic tissues of the model mice might mediate the enhancing effect of SE on gastrointestinal motility. PMID:11833095

Perspective: Electronic systems of knowledge in the world of virtual microscopy.

PubMed

Maybury, Terrence; Farah, Camile S

2009-09-01

Across a broad range of medical disciplines, learning how to use an optical or light microscope has been a mandatory inclusion in the undergraduate curriculum. The development of virtual microscopy (VM) technology during the past 10 years has called into question the use of the optical microscope in educational contexts. VM allows slide specimens to be digitized, which, in turn, allows the computer to mimic the workings of the light microscope. This move from analog technology (the light microscope) to digital technology (the computer as microscope) is part of the many significant changes going on in education, a singular manifestation of the broader move from print-literate traditions of knowledge (requiring literacy) to an electronics-literate, or "electrate," mode (requiring "electracy"). VM is here used as an exemplar of this broad transition from literacy to electracy, some components of which include data deluge, a multimodal structure, and modularity. Understandably, this transition is important to clarify educationally, especially in a global context mediated via digital means. A related aspect of these educational changes is the move from teacher-directed learning to student-centered learning, or "user-led education," which points to a redefinition of "pedagogy" as "andragogy." The dissemination of the specific value of VM, then, is critical to both learners and teachers and to a more coherent understanding of electracy. A practical consequence of this clarity might be a better application of this knowledge in the evolving fields of computer simulation and telemedicine, areas in which today's medical students will need future expertise.

Efficacious cellular codelivery of doxorubicin and EGFP siRNA mediated by the composition of PLGA and PEI protected gold nanoparticles.

PubMed

Kumar, Krishan; Vulugundam, Gururaja; Jaiswal, Pradeep Kumar; Shyamlal, Bharti Rajesh Kumar; Chaudhary, Sandeep

2017-09-15

This study reports the simultaneous delivery of EGFP siRNA and the chemotherapeutic drug, doxorubicin by means of the composition that results from the electrostatic interaction between positively charged siRNA-complexes of gold nanoparticles (AuNPs) capped with PEI, 25kDa (P25-AuNPs) and negatively charged carboxymethyl cellulose formulated PLGA nanoparticles loaded with doxorubicin. The nanoparticles and their facile interaction were studied by means of dynamic light scattering (DLS), zeta potential, transmission electron microscopic (TEM) measurements. The flow cytometric and confocal microscopic analysis evidenced the simultaneous internalization of both labelled siRNA and doxorubin into around 55% of the HeLa cancer cell population. Fluorescence microscopic studies enabled the visual analysis of EGFP expressing HeLa cells which suggested that the composition mediated codelivery resulted in a substantial downregulation of EGFP expression and intracellular accumulation of doxorubicin. Interestingly, codelivery treatment resulted in an increased cellular delivery of doxorubicin when compared to PLGA-DOX alone treatment. On the other hand, the activity of siRNA complexes of PEI-AuNPs was completely retained even when they were part of composition. The results suggest that this formulation can serve as promising tool for delivery applications in combinatorial anticancer therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timmermans, F. J.; Otto, C.

New developments in the field of microscopy enable to acquire increasing amounts of information from large sample areas and at an increased resolution. Depending on the nature of the technique, the information may reveal morphological, structural, chemical, and still other sample characteristics. In research fields, such as cell biology and materials science, there is an increasing demand to correlate these individual levels of information and in this way to obtain a better understanding of sample preparation and specific sample properties. To address this need, integrated systems were developed that combine nanometer resolution electron microscopes with optical microscopes, which produce chemicallymore » or label specific information through spectroscopy. The complementary information from electron microscopy and light microscopy presents an opportunity to investigate a broad range of sample properties in a correlated fashion. An important part of correlating the differences in information lies in bridging the different resolution and image contrast features. The trend to analyse samples using multiple correlated microscopes has resulted in a new research field. Current research is focused, for instance, on (a) the investigation of samples with nanometer scale distribution of inorganic and organic materials, (b) live cell analysis combined with electron microscopy, and (c) in situ spectroscopic and electron microscopy analysis of catalytic materials, but more areas will benefit from integrated correlative microscopy.« less

Silicone intraocular lens surface calcification in a patient with asteroid hyalosis.

PubMed

Matsumura, Kazuhiro; Takano, Masahiko; Shimizu, Kimiya; Nemoto, Noriko

2012-07-01

To confirm a substance presence on the posterior intraocular lens (IOL) surface in a patient with asteroid hyalosis. An 80-year-old man had IOLs for approximately 12 years. Opacities and neodymium-doped yttrium aluminum garnet pits were observed on the posterior surface of the right IOL. Asteroid hyalosis and an epiretinal membrane were observed OD. An IOL exchange was performed on 24 March 2008, and the explanted IOL was analyzed using a light microscope and a transmission electron microscope with a scanning electron micrograph and an energy-dispersive X-ray spectrometer for elemental analysis. To confirm asteroid hyalosis, asteroid bodies were examined with the ionic liquid (EtMeIm+ BF4-) method using a field emission scanning electron microscope (FE-SEM) with digital beam control RGB mapping. X-ray spectrometry of the deposits revealed high calcium and phosphorus peaks. Spectrometry revealed that the posterior IOL surface opacity was due to a calcium-phosphorus compound. Examination of the asteroid bodies using FE-SEM with digital beam control RGB mapping confirmed calcium and phosphorus as the main components. Calcium hydrogen phosphate dihydrate deposits were probably responsible for the posterior IOL surface opacity. Furthermore, analysis of the asteroid bodies demonstrated that calcium and phosphorus were its main components.

The microscopes of Antoni van Leeuwenhoek.

PubMed

van Zuylen, J

1981-03-01

The seventeenth-century Dutch microscopist, Antoni van Leeuwenhoek, was the first man to make a protracted study of microscopical objects, and, unlike his contemporary Robert Hooke, he viewed by transmitted light. Leeuwenhoek made over 500 of his own, curious, simple microscopes, but now only nine are known to exist. The exact nature of the lenses Leeuwenhoek made, has for long been a puzzle. The existing microscopes have now been examined in detail, and their optical characteristics measured and tabulated. It is proposed that the lens of highest magnification, x 266, was made using a special blown bubble technique.

Titania modified activated carbon prepared from sugarcane bagasse: adsorption and photocatalytic degradation of methylene blue under visible light irradiation.

PubMed

El-Salamony, R A; Amdeha, E; Ghoneim, S A; Badawy, N A; Salem, K M; Al-Sabagh, A M

2017-12-01

Activated carbon (AC), prepared from sugarcane bagasse waste through a low-temperature chemical carbonization treatment, was used as a support for nano-TiO 2 . TiO 2 supported on AC (xTiO 2 -AC) catalysts (x = 10, 20, 50, and 70 wt.%) were prepared through a mechano-mixing method. The photocatalysts were characterized by Raman, X-ray diffraction analysis, FTIR, S BET , field emission scanning electron microscope, and optical technique. The adsorption and photo-activity of the prepared catalysts (xTiO 2 -AC) were evaluated using methylene blue (MB) dye. The photocatalytic degradation of MB was evaluated under UVC irradiation and visible light. The degradation percentage of the 100 ppm MB at neutral pH using 20TiO 2 -AC reaches 96 and 91 after 180 min under visible light and UV irradiation, respectively. In other words, these catalysts are more active under visible light than under UV light irradiation, opening the possibility of using solar light for this application.

Rheological and structural properties of sea cucumber Stichopus japonicus during heat treatment

NASA Astrophysics Data System (ADS)

Gao, Xin; Xue, Dongmei; Zhang, Zhaohui; Xu, Jiachao; Xue, Changhu

2005-07-01

Changes in tissue structure, rheological properties and water content of raw and heated sea cucumber meat were studied. Sea cucumber Stichopus japonicus was heated at 25°C , 70°C and 100°C water for 5 min. The structural changes were observed using a light microscope and the rheological parameters (rupture strength, adhesive strength and deformation) determined using a texture meter. Microscopic photograph revealed that the structural change of heated meat was greater than that of raw meat. The rupture strength, adhesive strength and deformation of raw meat were smaller than those of the heated meat. Meanwhile, rheological parameters showed positive correlation with heating temperature. These changes are mainly caused by thermal denaturation and gelatinization of collagen during heating. These changes were also evidenced in observations using a light microscope and differential scanning calorimetry.

Sheet-scanned dual-axis confocal microscopy using Richardson-Lucy deconvolution.

PubMed

Wang, D; Meza, D; Wang, Y; Gao, L; Liu, J T C

2014-09-15

We have previously developed a line-scanned dual-axis confocal (LS-DAC) microscope with subcellular resolution suitable for high-frame-rate diagnostic imaging at shallow depths. Due to the loss of confocality along one dimension, the contrast (signal-to-background ratio) of a LS-DAC microscope is deteriorated compared to a point-scanned DAC microscope. However, by using a sCMOS camera for detection, a short oblique light-sheet is imaged at each scanned position. Therefore, by scanning the light sheet in only one dimension, a thin 3D volume is imaged. Both sequential two-dimensional deconvolution and three-dimensional deconvolution are performed on the thin image volume to improve the resolution and contrast of one en face confocal image section at the center of the volume, a technique we call sheet-scanned dual-axis confocal (SS-DAC) microscopy.

Fabrication and characterization of novel microsphere-embedded optical devices for enhancing microscopy resolution

NASA Astrophysics Data System (ADS)

Darafsheh, Arash

2018-02-01

Microsphere-assisted imaging can be incorporated onto conventional light microscopes allowing wide-field and flourescence imaging with enhanced resolution. We demonstrated that imaging of specimens containing subdiffraction-limited features is achievable through high-index microspheres embedded in a transparent thin film placed over the specimen. We fabricated novel microsphere-embedded microscope slides composed of barium titanate glass microspheres (with diameter 10-100 μm and refractive index 1.9-2.2) embedded in a transparent polydimethylsiloxane (PDMS) elastomer layer with controllable thickness. We characterized the imaging performance of such microsphere-embedded devices in white-light microscopies, by measuring the imaging resolution, field-of-view, and magnification as a function of microsphere size. Our results inform on the design of novel optical devices, such as microsphere-embedded microscope slides for imaging applications.

Microscopic colitis syndrome.

PubMed Central

Veress, B; Löfberg, R; Bergman, L

1995-01-01

The colorectal biopsy specimens from 30 patients with chronic watery diarrhoea but normal endoscopic and radiographic findings were studied by light microscopy, morphometry, immunohistochemistry, and two patients with electron microscopy. The histological changes in the colorectum were originally diagnosed in six patients as lymphocytic colitis and in 24 patients as collagenous colitis. The analysis of the specimens for this study could delineate three distinct groups of microscopic colitis: lymphocytic colitis (six patients), collagenous colitis without lymphocytic attack on the surface epithelium (seven patients), and a mixed form presenting with both thickening of the collagen plate and increased number of intraepithelial lymphocytes (17 patients). No transformation was seen from one type to another during follow up of six patients for four to seven years. Increased numbers of active pericryptal myofibroblasts were found with the electron microscope in one patient with mixed microscopic colitis showing also myofibroblasts entrapped within the collagen layer. Hitherto undescribed flat mucosa of the ileum was found in one patient with lymphocytic colitis and both flat mucosa and thickening of the collagen plate in the ileum were seen in one patient with the mixed form of the disease. In another patient with mixed microscopic colitis, normalisation of the colorectal morphology occurred after temporary loop ileostomy, followed by the reappearance of both diarrhoea, inflammation, and thickening of the collagen plate after the ileostomy was reversed. No association was found between non-steroid anti-inflammatory drug (NSAID) consumption and collagenous or mixed microscopic colitis. The primary cause of microscopic colitis is probably an immunological reaction to luminal antigen/s, perhaps of ileal origin. The engagement of the pericryptal myofibroblasts in the disease process might result in the development of the various forms of microscopic colitis. An inverse relation between intraepithelial lymphocyte count and collagen thickness may indicate that microscopic colitis is a spectral disease. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7615277

Imaging Schwarzschild multilayer X-ray microscope

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Baker, Phillip C.; Shealy, David L.; Core, David B.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Kerstetter, Ted

1993-01-01

We have designed, analyzed, fabricated, and tested Schwarzschild multilayer X-ray microscopes. These instruments use flow-polished Zerodur mirror substrates which have been coated with multilayers optimized for maximum reflectivity at normal incidence at 135 A. They are being developed as prototypes for the Water Window Imaging X-Ray Microscope. Ultrasmooth mirror sets of hemlite grade sapphire have been fabricated and they are now being coated with multilayers to reflect soft X-rays at 38 A, within the biologically important 'water window'. In this paper, we discuss the fabrication of the microscope optics and structural components as well as the mounting of the optics and assembly of the microscopes. We also describe the optical alignment, interferometric and visible light testing of the microscopes, present interferometrically measured performance data, and provide the first results of optical imaging tests.

Effect of 3C-SiC intermediate layer in GaN—based light emitting diodes grown on Si(111) substrate

NASA Astrophysics Data System (ADS)

Zhu, Youhua; Wang, Meiyu; Li, Yi; Tan, Shuxin; Deng, Honghai; Guo, Xinglong; Yin, Haihong; Egawa, Takashi

2017-03-01

GaN-based light emitting diodes (LEDs) have been grown by metalorganic chemical vapor deposition on Si(111) substrate with and without 3C-SiC intermediate layer (IL). Structural property has been characterized by means of atomic force microscope, X-ray diffraction, and transmission electron microscope measurements. It has been revealed that a significant improvement in crystalline quality of GaN and superlattice epitaxial layers can be achieved by using 3C-SiC as IL. Regarding of electrical and optical characteristics, it is clearly observed that the LEDs with its IL have a smaller leakage current and higher light output power comparing with the LEDs without IL. The better performance of LEDs using 3C-SiC IL can be contributed to both of the improvements in epitaxial layers quality and light extraction efficiency. As a consequence, in terms of optical property, a double enhancement of the light output power and external quantum efficiency has been realized.

Arrays of microscopic organic LEDs for high-resolution optogenetics

PubMed Central

Steude, Anja; Witts, Emily C.; Miles, Gareth B.; Gather, Malte C.

2016-01-01

Optogenetics is a paradigm-changing new method to study and manipulate the behavior of cells with light. Following major advances of the used genetic constructs over the last decade, the light sources required for optogenetic control are now receiving increased attention. We report a novel optogenetic illumination platform based on high-density arrays of microscopic organic light-emitting diodes (OLEDs). Because of the small dimensions of each array element (6 × 9 μm2) and the use of ultrathin device encapsulation, these arrays enable illumination of cells with unprecedented spatiotemporal resolution. We show that adherent eukaryotic cells readily proliferate on these arrays, and we demonstrate specific light-induced control of the ionic current across the membrane of individual live cells expressing different optogenetic constructs. Our work paves the way for the use of OLEDs for cell-specific optogenetic control in cultured neuronal networks and for acute brain slices, or as implants in vivo. PMID:27386540

Malaria Diagnosis Using a Mobile Phone Polarized Microscope

NASA Astrophysics Data System (ADS)

Pirnstill, Casey W.; Coté, Gerard L.

2015-08-01

Malaria remains a major global health burden, and new methods for low-cost, high-sensitivity, diagnosis are essential, particularly in remote areas with low-resource around the world. In this paper, a cost effective, optical cell-phone based transmission polarized light microscope system is presented for imaging the malaria pigment known as hemozoin. It can be difficult to determine the presence of the pigment from background and other artifacts, even for skilled microscopy technicians. The pigment is much easier to observe using polarized light microscopy. However, implementation of polarized light microscopy lacks widespread adoption because the existing commercial devices have complicated designs, require sophisticated maintenance, tend to be bulky, can be expensive, and would require re-training for existing microscopy technicians. To this end, a high fidelity and high optical resolution cell-phone based polarized light microscopy system is presented which is comparable to larger bench-top polarized microscopy systems but at much lower cost and complexity. The detection of malaria in fixed and stained blood smears is presented using both, a conventional polarized microscope and our cell-phone based system. The cell-phone based polarimetric microscopy design shows the potential to have both the resolution and specificity to detect malaria in a low-cost, easy-to-use, modular platform.

Malaria Diagnosis Using a Mobile Phone Polarized Microscope

PubMed Central

Pirnstill, Casey W.; Coté, Gerard L.

2015-01-01

Malaria remains a major global health burden, and new methods for low-cost, high-sensitivity, diagnosis are essential, particularly in remote areas with low-resource around the world. In this paper, a cost effective, optical cell-phone based transmission polarized light microscope system is presented for imaging the malaria pigment known as hemozoin. It can be difficult to determine the presence of the pigment from background and other artifacts, even for skilled microscopy technicians. The pigment is much easier to observe using polarized light microscopy. However, implementation of polarized light microscopy lacks widespread adoption because the existing commercial devices have complicated designs, require sophisticated maintenance, tend to be bulky, can be expensive, and would require re-training for existing microscopy technicians. To this end, a high fidelity and high optical resolution cell-phone based polarized light microscopy system is presented which is comparable to larger bench-top polarized microscopy systems but at much lower cost and complexity. The detection of malaria in fixed and stained blood smears is presented using both, a conventional polarized microscope and our cell-phone based system. The cell-phone based polarimetric microscopy design shows the potential to have both the resolution and specificity to detect malaria in a low-cost, easy-to-use, modular platform. PMID:26303238

Eliminating Unwanted Far-Field Excitation in Objective-Type TIRF. Part I. Identifying Sources of Nonevanescent Excitation Light

PubMed Central

Brunstein, Maia; Teremetz, Maxime; Hérault, Karine; Tourain, Christophe; Oheim, Martin

2014-01-01

Total internal reflection fluorescence microscopy (TIRFM) achieves subdiffraction axial sectioning by confining fluorophore excitation to a thin layer close to the cell/substrate boundary. However, it is often unknown how thin this light sheet actually is. Particularly in objective-type TIRFM, large deviations from the exponential intensity decay expected for pure evanescence have been reported. Nonevanescent excitation light diminishes the optical sectioning effect, reduces contrast, and renders TIRFM-image quantification uncertain. To identify the sources of this unwanted fluorescence excitation in deeper sample layers, we here combine azimuthal and polar beam scanning (spinning TIRF), atomic force microscopy, and wavefront analysis of beams passing through the objective periphery. Using a variety of intracellular fluorescent labels as well as negative staining experiments to measure cell-induced scattering, we find that azimuthal beam spinning produces TIRFM images that more accurately portray the real fluorophore distribution, but these images are still hampered by far-field excitation. Furthermore, although clearly measureable, cell-induced scattering is not the dominant source of far-field excitation light in objective-type TIRF, at least for most types of weakly scattering cells. It is the microscope illumination optical path that produces a large cell- and beam-angle invariant stray excitation that is insensitive to beam scanning. This instrument-induced glare is produced far from the sample plane, inside the microscope illumination optical path. We identify stray reflections and high-numerical aperture aberrations of the TIRF objective as one important source. This work is accompanied by a companion paper (Pt.2/2). PMID:24606927

Estimation of safe exposure time from an ophthalmic operating microscope with regard to ultraviolet radiation and blue-light hazards to the eye

NASA Astrophysics Data System (ADS)

Michael, Ralph; Wegener, Alfred

2004-08-01

Hazards from the optical radiation of an operating microscope that cause damage at the corneal, lenticular, and retinal levels were investigated; we considered, in particular, ultraviolet radiation (UVR) and blue light. The spectral irradiance from a Zeiss operation microscope OPMI VISU 200 was measured in the corneal plane between 300 and 1100 nm. Effective irradiance and radiance were calculated with relative spectral effectiveness data from the American Conference for Governmental and Industrial Hygienists. Safe exposure time to avoid UVR injury to the lens and cornea was found to be 2 h without a filter, 4 h with a UVR filter, 200 h with a yellow filter, and 400 h with a filter combination. Safe exposure time to avoid retinal photochemical injury was found to be 3 min without a filter and with a UVR filter, 10 min with a yellow filter, and 49 min with a filter combination. The effective radiance limit for retinal thermal injury was not exceeded. The hazard due to the UVR component from the operating microscope is not critical, and operation time can be safely prolonged with the use of appropriate filters. The retinal photochemical hazard appears critical without appropriate filters, permitting only some minutes of safe exposure time. The calculated safe exposure times are for worst-case conditions and maximal light output and include a safety factor.

Operating microscope light-induced phototoxic maculopathy after transscleral sutured posterior chamber intraocular lens implantation.

PubMed

Kweon, Eui Yong; Ahn, Min; Lee, Dong Wook; You, In Cheon; Kim, Min Jung; Cho, Nam Chun

2009-01-01

The purpose of this study is to report the features of operating microscope light-induced retinal phototoxic maculopathy after transscleral sutured posterior chamber intraocular lens (TSS PC-IOL) implantation. The charts of 118 patients who underwent TSS PC-IOL implantation surgery at Chonbuk National University Hospital (Jeonju, Korea) between March 1999 and February 2008 were retrospectively reviewed. Fourteen patients underwent combined 3-port pars plana vitrectomy and TSS PC-IOL implantation (vitrectomy group), and 104 patients underwent TSS PC-IOL implantation only (nonvitrectomy group). All surgeries were performed under the same coaxial illuminated microscope. All diagnoses were confirmed through careful fundus examination and fluorescein angiography (FA). Diagnoses of retinal phototoxic maculopathy were established in 10 (8.47%) of 118 TSS PC-IOL implantation cases. Phototoxic maculopathy occurred more frequently in the vitrectomy group than in the nonvitrectomy group (6/14 versus 4/104, respectively; P < 0.001, chi-square = 24.21). Affected patients reported decreased vision and were found to have coarse alterations of the retinal pigment epithelium (RPE). In 5 of the phototoxic maculopathy cases (50%), the visual acuity was 20/200 or worse. Operating microscope light-induced retinal phototoxic maculopathy can occur more frequently after TSS PC-IOL implantation than after casual cataract surgery, especially when TSS PC-IOL is combined with vitrectomy surgery. Surgeons should take precautions to prevent retinal phototoxicity after TSS PC-IOL implantation and vitrectomy.

Estimation of safe exposure time from an ophthalmic operating microscope with regard to ultraviolet radiation and blue-light hazards to the eye.

PubMed

Michael, Ralph; Wegener, Alfred

2004-08-01

Hazards from the optical radiation of an operating microscope that cause damage at the corneal, lenticular, and retinal levels were investigated; we considered, in particular, ultraviolet radiation (UVR) and blue light. The spectral irradiance from a Zeiss operation microscope OPMI VISU 200 was measured in the corneal plane between 300 and 1100 nm. Effective irradiance and radiance were calculated with relative spectral effectiveness data from the American Conference for Governmental and Industrial Hygienists. Safe exposure time to avoid UVR injury to the lens and cornea was found to be 2 h without a filter, 4 h with a UVR filter, 200 a yellow filter, and 400 h with a filter combination. Safe exposure time to avoid retinal photochemical injury was found to be 3 min without a filter and with a UVR filter, 10 min with a yellow filter, and 49 min with a filter combination. The effective radiance limit for retinal thermal injury was not exceeded. The hazard due to the UVR component from the operating microscope is not critical, and operation time can be safely prolonged with the use of appropriate filters. The retinal photochemical hazard appears critical without appropriate filters, permitting only some minutes of safe exposure time. The calculated safe exposure times are for worst-case conditions and maximal light output and include a safety factor.

eduSPIM: Light Sheet Microscopy in the Museum

PubMed Central

Schmid, Benjamin; Weber, Michael; Huisken, Jan

2016-01-01

Light Sheet Microscopy in the Museum Light sheet microscopy (or selective plane illumination microscopy) is an important imaging technique in the life sciences. At the same time, this technique is also ideally suited for community outreach projects, because it produces visually appealing, highly dynamic images of living organisms and its working principle can be understood with basic optics knowledge. Still, the underlying concepts are widely unknown to the non-scientific public. On the occasion of the UNESCO International Year of Light, a technical museum in Dresden, Germany, launched a special, interactive exhibition. We built a fully functional, educational selective plane illumination microscope (eduSPIM) to demonstrate how developments in microscopy promote discoveries in biology. Design Principles of an Educational Light Sheet Microscope To maximize educational impact, we radically reduced a standard light sheet microscope to its essential components without compromising functionality and incorporated stringent safety concepts beyond those needed in the lab. Our eduSPIM system features one illumination and one detection path and a sealed sample chamber. We image fixed zebrafish embryos with fluorescent vasculature, because the structure is meaningful to laymen and visualises the optical principles of light sheet microscopy. Via a simplified interface, visitors acquire fluorescence and transmission data simultaneously. The eduSPIM Design Is Tailored Easily to Fit Numerous Applications The universal concepts presented here may also apply to other scientific approaches that are communicated to laymen in interactive settings. The specific eduSPIM design is adapted easily for various outreach and teaching activities. eduSPIM may even prove useful for labs needing a simple SPIM. A detailed parts list and schematics to rebuild eduSPIM are provided. PMID:27560188

Sub-diffraction limit resolution in microscopy

NASA Technical Reports Server (NTRS)

Cheng, Ming (Inventor); Chen, Weinong (Inventor)

2007-01-01

A method and apparatus for visualizing sub-micron size particles employs a polarizing microscope wherein a focused beam of polarized light is projected onto a target, and a portion of the illuminating light is blocked from reaching the specimen, whereby to produce a shadow region, and projecting diffracted light from the target onto the shadow region.

Digital holographic microscope with low-frequency attenuation filter for position measurement of a nanoparticle.

PubMed

Pham, Quang Duc; Kusumi, Yuichi; Hasegawa, Satoshi; Hayasaki, Yoshio

2012-10-01

We propose a new method for three-dimensional (3D) position measurement of nanoparticles using an in-line digital holographic microscope. The method improves the signal-to-noise ratio of the amplitude of the interference fringes to achieve higher accuracy in the position measurement by increasing weak scattered light from a nanoparticle relative to the reference light by using a low spatial frequency attenuation filter. We demonstrated the improvements of signal-to-noise ratio of the optical system and contrast of the interference fringes, allowing the 3D positions of nanoparticles to be determined more precisely.

Estimation of polydispersity in aggregating red blood cells by quantitative ultrasound backscatter analysis.

PubMed

de Monchy, Romain; Rouyer, Julien; Destrempes, François; Chayer, Boris; Cloutier, Guy; Franceschini, Emilie

2018-04-01

Quantitative ultrasound techniques based on the backscatter coefficient (BSC) have been commonly used to characterize red blood cell (RBC) aggregation. Specifically, a scattering model is fitted to measured BSC and estimated parameters can provide a meaningful description of the RBC aggregates' structure (i.e., aggregate size and compactness). In most cases, scattering models assumed monodisperse RBC aggregates. This study proposes the Effective Medium Theory combined with the polydisperse Structure Factor Model (EMTSFM) to incorporate the polydispersity of aggregate size. From the measured BSC, this model allows estimating three structural parameters: the mean radius of the aggregate size distribution, the width of the distribution, and the compactness of the aggregates. Two successive experiments were conducted: a first experiment on blood sheared in a Couette flow device coupled with an ultrasonic probe, and a second experiment, on the same blood sample, sheared in a plane-plane rheometer coupled to a light microscope. Results demonstrated that the polydisperse EMTSFM provided the best fit to the BSC data when compared to the classical monodisperse models for the higher levels of aggregation at hematocrits between 10% and 40%. Fitting the polydisperse model yielded aggregate size distributions that were consistent with direct light microscope observations at low hematocrits.

Diffuse light-sheet microscopy for stripe-free calcium imaging of neural populations.

PubMed

Taylor, Michael A; Vanwalleghem, Gilles C; Favre-Bulle, Itia A; Scott, Ethan K

2018-06-19

Light-sheet microscopy is used extensively in developmental biology and neuroscience. One limitation of this approach is that absorption and scattering produces shadows in the illuminating light sheet, resulting in stripe artifacts. Here, we introduce diffuse light-sheet microscopes that use a line diffuser to randomize the light propagation within the image plane, allowing the light sheets to reform after obstacles. We incorporate diffuse light sheets in two existing configurations: selective plane illumination microscopy (SPIM) in which the sample is illuminated with a static sheet of light, and digitally scanned light sheet (DSLS) in which a thin Gaussian beam is scanned across the image plane during each acquisition. We compare diffuse light-sheet microscopes to their conventional counterparts for calcium imaging of neural activity in larval zebrafish. We show that stripe artifacts can cast deep shadows that conceal some neurons, and that the stripes can flicker, producing spurious signals that could be interpreted as biological activity. Diffuse light sheets mitigate these problems, illuminating the blind spots produced by stripes and removing artifacts produced by the stripes' movements. The upgrade to diffuse light sheets is simple and inexpensive, especially in the case of DSLS, where it requires the addition of one optical element. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Synthesis, characterization, and magnetic properties of ZnO-ZnFe2O4 nanoparticles with high photocatalytic activity

NASA Astrophysics Data System (ADS)

Falak, P.; Hassanzadeh-Tabrizi, S. A.; Saffar-Teluri, A.

2017-11-01

In the present research, a magnetic ZnO-ZnFe2O4 binary nanocomposite was synthesized by a one-step microemulsion method. The characteristics of the synthesized powders were characterized using various analytical instruments including X-ray diffraction, scanning electron microscope, transmission electron microscope, thermogravimetric and differential thermal analysis, vibrating sample magnetometer, and ultraviolet-visible spectroscopy. The results of transmission electron microscope proved that the synthesized nanoparticles have irregular morphologies and the average particle size is about 20 nm. The photocatalytic investigation of ZnO-ZnFe2O4 nanoparticles was carried out using methylene blue solution under UV light. The synthesized nanoparticles showed enhanced photocatalytic performance in comparison with the ZnO nanoparticles more than 40%. The magnetization saturation value of ZnO-ZnFe2O4 nanoparticles was about 5.8 emu/g, which was high enough to be magnetically removed by applying a magnetic field. The results showed that the magnetization and coercivity of the samples reduced by increasing calcination temperature.

Laser shock wave assisted patterning on NiTi shape memory alloy surfaces

NASA Astrophysics Data System (ADS)

Seyitliyev, Dovletgeldi; Li, Peizhen; Kholikov, Khomidkhodza; Grant, Byron; Karaca, Haluk E.; Er, Ali O.

2017-02-01

An advanced direct imprinting method with low cost, quick, and less environmental impact to create thermally controllable surface pattern using the laser pulses is reported. Patterned micro indents were generated on Ni50Ti50 shape memory alloys (SMA) using an Nd:YAG laser operating at 1064 nm combined with suitable transparent overlay, a sacrificial layer of graphite, and copper grid. Laser pulses at different energy densities which generates pressure pulses up to 10 GPa on the surface was focused through the confinement medium, ablating the copper grid to create plasma and transferring the grid pattern onto the NiTi surface. Scanning electron microscope (SEM) and optical microscope images of square pattern with different sizes were studied. One dimensional profile analysis shows that the depth of the patterned sample initially increase linearly with the laser energy until 125 mJ/pulse where the plasma further absorbs and reflects the laser beam. In addition, light the microscope image show that the surface of NiTi alloy was damaged due to the high power laser energy which removes the graphite layer.

Fiducial marker for correlating images

DOEpatents

Miller, Lisa Marie [Rocky Point, NY; Smith, Randy J [Wading River, NY; Warren, John B [Port Jefferson, NY; Elliott, Donald [Hampton Bays, NY

2011-06-21

The invention relates to a fiducial marker having a marking grid that is used to correlate and view images produced by different imaging modalities or different imaging and viewing modalities. More specifically, the invention relates to the fiducial marking grid that has a grid pattern for producing either a viewing image and/or a first analytical image that can be overlaid with at least one other second analytical image in order to view a light path or to image different imaging modalities. Depending on the analysis, the grid pattern has a single layer of a certain thickness or at least two layers of certain thicknesses. In either case, the grid pattern is imageable by each imaging or viewing modality used in the analysis. Further, when viewing a light path, the light path of the analytical modality cannot be visualized by viewing modality (e.g., a light microscope objective). By correlating these images, the ability to analyze a thin sample that is, for example, biological in nature but yet contains trace metal ions is enhanced. Specifically, it is desired to analyze both the organic matter of the biological sample and the trace metal ions contained within the biological sample without adding or using extrinsic labels or stains.

A Photomicrography Primer.

ERIC Educational Resources Information Center

Davidson, Michael W.

1991-01-01

Describes techniques and equipment which allows school microscopes to perform crossed-polarized light microscopy, reflected light microscopy, and photomicrography. Provides information on using chemicals from a high school stockroom to view crystals, viewing integrated circuits, and capturing images on film. Lists possible independent student…

Imaging System for Vaginal Surgery.

PubMed

Taylor, G Bernard; Myers, Erinn M

2015-12-01

The vaginal surgeon is challenged with performing complex procedures within a surgical field of limited light and exposure. The video telescopic operating microscope is an illumination and imaging system that provides visualization during open surgical procedures with a limited field of view. The imaging system is positioned within the surgical field and then secured to the operating room table with a maneuverable holding arm. A high-definition camera and Xenon light source allow transmission of the magnified image to a high-definition monitor in the operating room. The monitor screen is positioned above the patient for the surgeon and assistants to view real time throughout the operation. The video telescopic operating microscope system was used to provide surgical illumination and magnification during total vaginal hysterectomy and salpingectomy, midurethral sling, and release of vaginal scar procedures. All procedures were completed without complications. The video telescopic operating microscope provided illumination of the vaginal operative field and display of the magnified image onto high-definition monitors in the operating room for the surgeon and staff to simultaneously view the procedures. The video telescopic operating microscope provides high-definition display, magnification, and illumination during vaginal surgery.

Cell-phone-based platform for biomedical device development and education applications.

PubMed

Smith, Zachary J; Chu, Kaiqin; Espenson, Alyssa R; Rahimzadeh, Mehdi; Gryshuk, Amy; Molinaro, Marco; Dwyre, Denis M; Lane, Stephen; Matthews, Dennis; Wachsmann-Hogiu, Sebastian

2011-03-02

In this paper we report the development of two attachments to a commercial cell phone that transform the phone's integrated lens and image sensor into a 350x microscope and visible-light spectrometer. The microscope is capable of transmission and polarized microscopy modes and is shown to have 1.5 micron resolution and a usable field-of-view of 150 x 50 with no image processing, and approximately 350 x 350 when post-processing is applied. The spectrometer has a 300 nm bandwidth with a limiting spectral resolution of close to 5 nm. We show applications of the devices to medically relevant problems. In the case of the microscope, we image both stained and unstained blood-smears showing the ability to acquire images of similar quality to commercial microscope platforms, thus allowing diagnosis of clinical pathologies. With the spectrometer we demonstrate acquisition of a white-light transmission spectrum through diffuse tissue as well as the acquisition of a fluorescence spectrum. We also envision the devices to have immediate relevance in the educational field.

Cell-Phone-Based Platform for Biomedical Device Development and Education Applications

PubMed Central

Smith, Zachary J.; Chu, Kaiqin; Espenson, Alyssa R.; Rahimzadeh, Mehdi; Gryshuk, Amy; Molinaro, Marco; Dwyre, Denis M.; Lane, Stephen; Matthews, Dennis; Wachsmann-Hogiu, Sebastian

2011-01-01

In this paper we report the development of two attachments to a commercial cell phone that transform the phone's integrated lens and image sensor into a 350× microscope and visible-light spectrometer. The microscope is capable of transmission and polarized microscopy modes and is shown to have 1.5 micron resolution and a usable field-of-view of 150×150 with no image processing, and approximately 350×350 when post-processing is applied. The spectrometer has a 300 nm bandwidth with a limiting spectral resolution of close to 5 nm. We show applications of the devices to medically relevant problems. In the case of the microscope, we image both stained and unstained blood-smears showing the ability to acquire images of similar quality to commercial microscope platforms, thus allowing diagnosis of clinical pathologies. With the spectrometer we demonstrate acquisition of a white-light transmission spectrum through diffuse tissue as well as the acquisition of a fluorescence spectrum. We also envision the devices to have immediate relevance in the educational field. PMID:21399693

Light-sheet enhanced resolution of light field microscopy for rapid imaging of large volumes

NASA Astrophysics Data System (ADS)

Madrid Wolff, Jorge; Castro, Diego; Arbeláez, Pablo; Forero-Shelton, Manu

2018-02-01

Whole-brain imaging is challenging because it demands microscopes with high temporal and spatial resolution, which are often at odds, especially in the context of large fields of view. We have designed and built a light-sheet microscope with digital micromirror illumination and light-field detection. On the one hand, light sheets provide high resolution optical sectioning on live samples without compromising their viability. On the other hand, light field imaging makes it possible to reconstruct full volumes of relatively large fields of view from a single camera exposure; however, its enhanced temporal resolution comes at the expense of spatial resolution, limiting its applicability. We present an approach to increase the resolution of light field images using DMD-based light sheet illumination. To that end, we develop a method to produce synthetic resolution targets for light field microscopy and a procedure to correct the depth at which planes are refocused with rendering software. We measured the axial resolution as a function of depth and show a three-fold potential improvement with structured illumination, albeit by sacrificing some temporal resolution, also three-fold. This results in an imaging system that may be adjusted to specific needs without having to reassemble and realign it. This approach could be used to image relatively large samples at high rates.

A pragmatic guide to multiphoton microscope design

PubMed Central

Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

2016-01-01

Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

A relic of the Wellcome Tropical Research Laboratories in Khartoum (1903-34).

PubMed

Adeel, Ahmed Awad

2016-01-01

This article explores the origins of an old brass monocular microscope in the Central Laboratory in Khartoum, which used to be the Wellcome Tropical Research Laboratory in Khartoum (1903-1934). Examination of the microscope and review of published literature gave clues to the historical background of this microscope. Identical microscopes were first manufactured by R and J Beck in 1898, and continued to be advertised in 1899. The microscope was probably among the instruments provided by Wellcome for the initial establishment of the laboratories in 1902-1903. The article includes a brief review of the development of light microscopy. The need for preservation and proper restoration of old relics of the Wellcome laboratories in Khartoum is emphasized.

A relic of the Wellcome Tropical Research Laboratories in Khartoum (1903–34)

PubMed Central

2016-01-01

This article explores the origins of an old brass monocular microscope in the Central Laboratory in Khartoum, which used to be the Wellcome Tropical Research Laboratory in Khartoum (1903–1934). Examination of the microscope and review of published literature gave clues to the historical background of this microscope. Identical microscopes were first manufactured by R and J Beck in 1898, and continued to be advertised in 1899. The microscope was probably among the instruments provided by Wellcome for the initial establishment of the laboratories in 1902–1903. The article includes a brief review of the development of light microscopy. The need for preservation and proper restoration of old relics of the Wellcome laboratories in Khartoum is emphasized. PMID:27651557

3D interferometric microscope: color visualization of engineered surfaces for industrial applications

NASA Astrophysics Data System (ADS)

Schmit, Joanna; Novak, Matt; Bui, Son

2015-09-01

3D microscopes based on white light interference (WLI) provide precise measurement for the topography of engineering surfaces. However, the display of an object in its true colors as observed under white illumination is often desired; this traditionally has presented a challenge for WLI-based microscopes. Such 3D color display is appealing to the eye and great for presentations, and also provides fast evaluation of certain characteristics like defects, delamination, or deposition of different materials. Determination of color as observed by interferometric objectives is not straightforward; we will present how color imaging capabilities similar to an ordinary microscope can be obtained in interference microscopes based on WLI and we will give measurement and imaging examples of a few industrial samples.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity.

PubMed

Frost, William N; Wang, Jean; Brandon, Christopher J

2007-05-15

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations.

Laser and biological methods of biomonitoring of surrounding waters

NASA Astrophysics Data System (ADS)

Posudin, Yuri I.

1994-02-01

Three main methods are proposed for the biomonitoring of chemicals in water medium: laser spectrofluorometry, which is based on the excitation and recording of the spectra of fluorescence; laser scattering, which is connected with measurement of the Doppler shifts of the scattered light from the motile cells; videomicrography, which provides the analysis of parameters of photomovement of motile cells via microscope and video system. Such chemicals as surface-active substances, heavy metals and pesticides were determined in water medium due to these methods.

The calibration of photographic and spectroscopic films: 1: A microscopic analysis of IIaO films. 2: The effects of agitation and soaking on IIaO films. 3: The effects of electric field on IIaO films. 4: The effects of X-ray radiation on IIaO films

NASA Technical Reports Server (NTRS)

Hammond, E. C., Jr.; Peters, K.; Boone, K.

1978-01-01

The grain structure of the emulsion using both reflected and transmission light was examined along with the effects of soaking. The effect of a static charge by a Tesla-coil, and the effects of airport equipment, and dental X-rays on the film were also analyzed.

High-resolution microscope for tip-enhanced optical processes in ultrahigh vacuum

NASA Astrophysics Data System (ADS)

Steidtner, Jens; Pettinger, Bruno

2007-10-01

An optical microscope based on tip-enhanced optical processes that can be used for studies on adsorbates as well as thin layers and nanostructures is presented. The microscope provides chemical and topographic informations with a resolution of a few nanometers and can be employed in ultrahigh vacuum as well as gas phase. The construction involves a number of improvements compared to conventional instruments. The central idea is to mount, within an UHV system, an optical platform with all necessary optical elements to a rigid frame that also carries the scanning tunneling microscope unit and to integrate a high numerical aperture parabolic mirror between the scanning probe microscope head and the sample. The parabolic mirror serves to focus the incident light and to collect a large fraction of the scattered light. The first experimental results of Raman measurements on silicon samples as well as brilliant cresyl blue layers on single crystalline gold and platinum surfaces in ultrahigh vacuum are presented. For dye adsorbates a Raman enhancement of ˜106 and a net signal gain of up to 4000 was observed. The focus diameter (˜λ/2) was measured by Raman imaging the focal region on a Si surface. The requirements of the parabolic mirror in terms of alignment accuracy were experimentally determined as well.

A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yang; Maurer, Jürgen; Roth, Andreas

A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the depositionmore » of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.« less

A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

NASA Astrophysics Data System (ADS)

Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner

2014-08-01

A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

Evidence for Rhythmicity Pacemaker in the Calcification Process of Scleractinian Coral

NASA Astrophysics Data System (ADS)

Gutner-Hoch, Eldad; Schneider, Kenneth; Stolarski, Jaroslaw; Domart-Coulon, Isabelle; Yam, Ruth; Meibom, Anders; Shemesh, Aldo; Levy, Oren

2016-02-01

Reef-building scleractinian (stony) corals are among the most efficient bio-mineralizing organisms in nature. The calcification rate of scleractinian corals oscillates under ambient light conditions, with a cyclic, diurnal pattern. A fundamental question is whether this cyclic pattern is controlled by exogenous signals or by an endogenous ‘biological-clock’ mechanism, or both. To address this problem, we have studied calcification patterns of the Red Sea scleractinian coral Acropora eurystoma with frequent measurements of total alkalinity (AT) under different light conditions. Additionally, skeletal extension and ultra-structure of newly deposited calcium carbonate were elucidated with 86Sr isotope labeling analysis, combined with NanoSIMS ion microprobe and scanning electron microscope imaging. Our results show that the calcification process persists with its cyclic pattern under constant light conditions while dissolution takes place within one day of constant dark conditions, indicating that an intrinsic, light-entrained mechanism may be involved in controlling the calcification process in photosymbiotic corals.

Assessment of incomplete clipping of aneurysms intraoperatively by a near-infrared indocyanine green-video angiography (Niicg-Va) integrated microscope.

PubMed

Imizu, S; Kato, Y; Sangli, A; Oguri, D; Sano, H

2008-08-01

The objective of this article was to assess the clinical use and the completeness of clipping with total occlusion of the aneurysmal lumen, real-time assessment of vascular patency in the parent, branching and perforating vessels, intraoperative assessment of blood flow, image quality, spatial resolution and clinical value in difficult aneurysms using near infrared indocyanine green video angiography integrated on to an operative Pentero neurosurgical microscope (Carl Zeiss, Oberkochen Germany). Thirteen patients with aneurysms were operated upon. An infrared camera with near infrared technology was adapted on to the OPMI Pentero microscope with a special filter and infrared excitation light to illuminate the operating field which was designed to allow passage of the near infrared light required for excitation of indocyanine green (ICG) which was used as the intravascular marker. The intravascular fluorescence was imaged with a video camera attached to the microscope. ICG fluorescence (700-850 nm) from a modified microscope light source on to the surgical field and passage of ICG fluorescence (780-950 nm) from the surgical field, back into the optical path of the microscope was used to detect the completeness of aneurysmal clipping Incomplete clipping in three patients (1 female and 2 males) with unruptured complicated aneurysms was detected using indocyanine green video angiography. There were no adverse effects after injection of indocyanine green. The completeness of clipping was inadequately detected by Doppler ultrasound miniprobe and rigid endoscopy and was thus complemented by indocyanine green video angiography. The operative microscope-integrated ICG video angiography as a new intraoperative method for detecting vascular flow, was found to be quick, reliable, cost-effective and possibly a substitute or adjunct for Doppler ultrasonography or intraoperative DSA, which is presently the gold standard. The simplicity of the method, the speed with which the investigation can be performed, the quality of the images, and the outcome of surgical procedures have all reduced the need for angiography. This technique may be useful during routine aneurysm surgery as an independent form of angiography and/or as an adjunct to intraoperative or postoperative DSA.

Polarized Light Microscopy in Reproductive and Developmental Biology

PubMed Central

KOIKE-TANI, MAKI; TANI, TOMOMI; MEHTA, SHALIN B.; VERMA, AMITABH; OLDENBOURG, RUDOLF

2016-01-01

SUMMARY The polarized light microscope reveals orientational order in native molecular structures inside living cells, tissues, and whole organisms. It is a powerful tool used to monitor and analyze the early developmental stages of organisms that lend themselves to microscopic observations. In this article, we briefly discuss the components specific to a traditional polarizing microscope and some historically important observations on: chromosome packing in the sperm head, the first zygote division of the sea urchin, and differentiation initiated by the first asymmetric cell division in the sand dollar. We then introduce the LC-PolScope and describe its use for measuring birefringence and polarized fluorescence in living cells and tissues. Applications range from the enucleation of mouse oocytes to analyzing the polarized fluorescence of the water strider acrosome. We end with new results on the birefringence of the developing chick brain, which we analyzed between developmental stages of days 12–20. PMID:23901032

Holographic photolysis of caged neurotransmitters

PubMed Central

Lutz, Christoph; Otis, Thomas S.; DeSars, Vincent; Charpak, Serge; DiGregorio, David A.; Emiliani, Valentina

2009-01-01

Stimulation of light-sensitive chemical probes has become a powerful tool for the study of dynamic signaling processes in living tissue. Classically, this approach has been constrained by limitations of lens–based and point-scanning illumination systems. Here we describe a novel microscope configuration that incorporates a nematic liquid crystal spatial light modulator (LC-SLM) to generate holographic patterns of illumination. This microscope can produce illumination spots of variable size and number and patterns shaped to precisely match user-defined elements in a specimen. Using holographic illumination to photolyse caged glutamate in brain slices, we demonstrate that shaped excitation on segments of neuronal dendrites and simultaneous, multi-spot excitation of different dendrites enables precise spatial and rapid temporal control of glutamate receptor activation. By allowing the excitation volume shape to be tailored precisely, the holographic microscope provides an extremely flexible method for activation of various photosensitive proteins and small molecules. PMID:19160517

The evolution of structured illumination microscopy in studies of HIV.

PubMed

Marno, Kelly; Al'Zoubi, Lara; Pearson, Matthew; Posch, Markus; McKnight, Áine; Wheeler, Ann P

2015-10-15

The resolution limit of conventional light microscopy has proven to be limiting for many biological structures such as viruses including Human immunodeficiency virus (HIV). Individual HIV virions are impossible to study using confocal microscopy as they are well below the 200 nm resolution limit of conventional light microscopes. Structured illumination microscopy (SIM) allows a twofold enhancement in image resolution compared to standard widefield illumination and so provides an excellent tool for study of HIV. Viral capsids (CAs) vary between 110 and 146 nm so this study challenges the performance of SIM microscopes. SIM microscopy was first developed in 2000, commercialised in 2007 and rapidly developed. Here we present the changes in capabilities of the SIM microscopes for study of HIV localisation as the instrumentation for structured illumination microscopy has evolved over the past 8 years. Copyright © 2015. Published by Elsevier Inc.

Scanning electron microscope cathodoluminescence imaging of subgrain boundaries, twins and planar deformation features in quartz

NASA Astrophysics Data System (ADS)

Hamers, M. F.; Pennock, G. M.; Drury, M. R.

2017-04-01

The study of deformation features has been of great importance to determine deformation mechanisms in quartz. Relevant microstructures in both growth and deformation processes include dislocations, subgrains, subgrain boundaries, Brazil and Dauphiné twins and planar deformation features (PDFs). Dislocations and twin boundaries are most commonly imaged using a transmission electron microscope (TEM), because these cannot directly be observed using light microscopy, in contrast to PDFs. Here, we show that red-filtered cathodoluminescence imaging in a scanning electron microscope (SEM) is a useful method to visualise subgrain boundaries, Brazil and Dauphiné twin boundaries. Because standard petrographic thin sections can be studied in the SEM, the observed structures can be directly and easily correlated to light microscopy studies. In contrast to TEM preparation methods, SEM techniques are non-destructive to the area of interest on a petrographic thin section.

Neuronal nitric oxide synthase immunopositive neurons in cat claustrum--a light and electron microscopic study.

PubMed

Hinova-Palova, Dimka; Edelstein, Lawrence; Paloff, Adrian; Hristov, Stanislav; Papantchev, Vassil; Ovtscharoff, Wladimir

2008-08-01

Nitric oxide is a unique neurotransmitter, which participates in many physiological and pathological processes in the organism. Nevertheless there are little data about the neuronal Nitric Oxide Synthase immunoreactive (nNOS-ir) neurons and fibers in the dorsal claustrum (DC) of a cat. In this respect the aims of this study were: (1) to demonstrate nNOS-ir in the neurons and fibers of the DC; (2) to describe their light microscopic morphology and distribution; (3) to investigate and analyze the ultrastructure of the nNOS-ir neurons, fibers and synaptic terminals; (4) to verify whether the nNOS-ir neurons consist a specific subpopulation of claustral neurons; (5) to verify whether the nNOS-ir neurons have a specific pattern of organization throughout the DC. For demonstration of the nNOS-ir the Avidin-Biotin-Peroxidase Complex method was applied. Immunopositive for nNOS neurons and fibers were present in all parts of DC. On the light microscope level nNOS-ir neurons were different in shape and size. According to the latter they were divided into three groups-small (with diameter under 15 microm), medium-sized (with diameter from 16 to 20 microm) and large (with diameter over 21 microm). Some of nNOS-ir neurons were lightly-stained while others were darkly-stained. On the electron microscope level the immunoproduct was observed in neurons, dendrites and terminal boutons. Different types of nNOS-ir neurons differ according to their ultrastructural features. Three types of nNOS-ir synaptic boutons were found. As a conclusion we hope that the present study will contribute to a better understanding of the functioning of the DC in cat and that some of the data presented could be extrapolated to other mammals, including human.

Strength and Deformability of Light-toned Layered Deposits Observed by MER Opportunity: Eagle to Erebus Craters

NASA Astrophysics Data System (ADS)

Okubo, C. H.; Schultz, R. A.; Nahm, A. L.

2007-07-01

The strength and deformability of light-toned layered deposits are estimated based on measurements of porosity from Microscopic Imager data acquired by MER Opportunity during its traverse from Eagle Crater to Erebus Crater.

Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams.

PubMed

Guzzinati, Giulio; Béché, Armand; Lourenço-Martins, Hugo; Martin, Jérôme; Kociak, Mathieu; Verbeeck, Jo

2017-04-12

Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations' symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations' symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria.

Angular reconstitution-based 3D reconstructions of nanomolecular structures from superresolution light-microscopy images

PubMed Central

Salas, Desirée; Le Gall, Antoine; Fiche, Jean-Bernard; Valeri, Alessandro; Ke, Yonggang; Bron, Patrick; Bellot, Gaetan

2017-01-01

Superresolution light microscopy allows the imaging of labeled supramolecular assemblies at a resolution surpassing the classical diffraction limit. A serious limitation of the superresolution approach is sample heterogeneity and the stochastic character of the labeling procedure. To increase the reproducibility and the resolution of the superresolution results, we apply multivariate statistical analysis methods and 3D reconstruction approaches originally developed for cryogenic electron microscopy of single particles. These methods allow for the reference-free 3D reconstruction of nanomolecular structures from two-dimensional superresolution projection images. Since these 2D projection images all show the structure in high-resolution directions of the optical microscope, the resulting 3D reconstructions have the best possible isotropic resolution in all directions. PMID:28811371

Composite charge 8/3 resonances at the LHC

NASA Astrophysics Data System (ADS)

Matsedonskyi, Oleksii; Riva, Francesco; Vantalon, Thibaud

2014-04-01

In composite Higgs models with partial compositeness, the small value of the observed Higgs mass implies the existence of light fermionic resonances, the top partners, whose quantum numbers are determined by the symmetry (and symmetry breaking) structure of the theory. Here we study light top partners with electric charge 8/3, which are predicted, for instance, in some of the most natural composite Higgs realizations. We recast data from two same sign lepton searches and from searches for microscopic blackholes into a bound on its mass, M 8/3 > 940 GeV. Furthermore, we compare potential reach of these searches with a specifically designed search for three same-sign leptons, both at 8 and 14TeV. We provide a simplified model, suitable for collider analysis.

Structural, electrical and photovoltaic properties of CoS/Si heterojunction prepared by spray pyrolysis

NASA Astrophysics Data System (ADS)

El Radaf, I. M.; Nasr, Mahmoud; Mansour, A. M.

2018-01-01

Au/p-CoS/n-Si/Al heterojunction device was fabricated by spray pyrolysis technique. The structural and morphological features were examined by x-ray diffraction, scanning electron microscope and energy dispersive x-ray analysis. The capacitance-voltage characteristics of the prepared heterojunction were analyzed at room temperature in the dark. The current-voltage characteristics were examined under dark and different incident light intensities 20-100 mW cm-2. The rectification ratio, series resistance, shunt resistance, diode ideality factor and the effective barrier height were determined at dark and illumination conditions. The photovoltaic parameters such as short circuit current density, open circuit voltage, fill factor and power conversion efficiency were calculated at different incident light intensities.

The Light-Velocity Postulate: The Essential Difference between the Theories of Lorentz-Poincare and Einstein

ERIC Educational Resources Information Center

Abiko, Seiya

2005-01-01

Einstein, who had already developed the light-quantum theory, knew the inadequacy of Maxwell's theory in the microscopic sphere. Therefore, in writing his paper on special relativity, he had to set up the light-velocity postulate independently of the relativity postulate in order to make the electromagnetic foundation of physics compatible with…

Multimodal Hierarchical Imaging of Serial Sections for Finding Specific Cellular Targets within Large Volumes

PubMed Central

Wacker, Irene U.; Veith, Lisa; Spomer, Waldemar; Hofmann, Andreas; Thaler, Marlene; Hillmer, Stefan; Gengenbach, Ulrich; Schröder, Rasmus R.

2018-01-01

Targeting specific cells at ultrastructural resolution within a mixed cell population or a tissue can be achieved by hierarchical imaging using a combination of light and electron microscopy. Samples embedded in resin are sectioned into arrays consisting of ribbons of hundreds of ultrathin sections and deposited on pieces of silicon wafer or conductively coated coverslips. Arrays are imaged at low resolution using a digital consumer like smartphone camera or light microscope (LM) for a rapid large area overview, or a wide field fluorescence microscope (fluorescence light microscopy (FLM)) after labeling with fluorophores. After post-staining with heavy metals, arrays are imaged in a scanning electron microscope (SEM). Selection of targets is possible from 3D reconstructions generated by FLM or from 3D reconstructions made from the SEM image stacks at intermediate resolution if no fluorescent markers are available. For ultrastructural analysis, selected targets are finally recorded in the SEM at high-resolution (a few nanometer image pixels). A ribbon-handling tool that can be retrofitted to any ultramicrotome is demonstrated. It helps with array production and substrate removal from the sectioning knife boat. A software platform that allows automated imaging of arrays in the SEM is discussed. Compared to other methods generating large volume EM data, such as serial block-face SEM (SBF-SEM) or focused ion beam SEM (FIB-SEM), this approach has two major advantages: (1) The resin-embedded sample is conserved, albeit in a sliced-up version. It can be stained in different ways and imaged with different resolutions. (2) As the sections can be post-stained, it is not necessary to use samples strongly block-stained with heavy metals to introduce contrast for SEM imaging or render the tissue blocks conductive. This makes the method applicable to a wide variety of materials and biological questions. Particularly prefixed materials e.g., from biopsy banks and pathology labs, can directly be embedded and reconstructed in 3D. PMID:29630046

A programmable light engine for quantitative single molecule TIRF and HILO imaging.

PubMed

van 't Hoff, Marcel; de Sars, Vincent; Oheim, Martin

2008-10-27

We report on a simple yet powerful implementation of objective-type total internal reflection fluorescence (TIRF) and highly inclined and laminated optical sheet (HILO, a type of dark-field) illumination. Instead of focusing the illuminating laser beam to a single spot close to the edge of the microscope objective, we are scanning during the acquisition of a fluorescence image the focused spot in a circular orbit, thereby illuminating the sample from various directions. We measure parameters relevant for quantitative image analysis during fluorescence image acquisition by capturing an image of the excitation light distribution in an equivalent objective backfocal plane (BFP). Operating at scan rates above 1 MHz, our programmable light engine allows directional averaging by circular spinning the spot even for sub-millisecond exposure times. We show that restoring the symmetry of TIRF/HILO illumination reduces scattering and produces an evenly lit field-of-view that affords on-line analysis of evanescnt-field excited fluorescence without pre-processing. Utilizing crossed acousto-optical deflectors, our device generates arbitrary intensity profiles in BFP, permitting variable-angle, multi-color illumination, or objective lenses to be rapidly exchanged.

Identification of powdered Chinese herbal medicines by fluorescence microscopy, Part 1: Fluorescent characteristics of mechanical tissues, conducting tissues, and ergastic substances.

PubMed

Wang, Ya-Qiong; Liang, Zhi-Tao; Li, Qin; Yang, Hua; Chen, Hu-Biao; Zhao, Zhong-Zhen; Li, Ping

2011-03-01

The light microscope has been successfully used in identification of Chinese herbal medicines (CHMs) for more than a century. However, positive identification is not always possible. Given the popularity of fluorescence microscopy in bioanalysis, researchers dedicated to finding new ways to identify CHMs more effectively are now turning to fluorescence microscopy for authentication purposes. Some studies on distinguishing confused species from the same genus and on exploring distributions of chemicals in tissues of CHMs by fluorescence microscopy have been reported; however, no systematic investigations on fluorescent characteristics of powdered CHMs have been reported. Here, 46 samples of 16 CHMs were investigated. Specifically, the mechanical tissues including stone cells and fibers, the conducting tissues including three types of vessels, and ergastic substances including crystals of calcium oxalate and secretions, in various powdered CHMs were investigated by both light microscope and fluorescence microscope. The results showed many microscopic features emit fluorescence that makes them easily observed, even against complex backgrounds. Under the fluorescence microscope, different microscopic features from the same powdered CHM or some same features from different powdered CHMs emitted the different fluorescence, making this information very helpful for the authentication of CHMs in powder form. Moreover, secretions with unique chemical profiles from different powdered CHMs showed different fluorescent characteristics. Hence, fluorescence microscopy could be a useful additional method for the authentication of powdered CHMs if the fluorescent characteristics of specific CHMs are known. Copyright © 2010 Wiley-Liss, Inc.

Automatic detection and analysis of cell motility in phase-contrast time-lapse images using a combination of maximally stable extremal regions and Kalman filter approaches.

PubMed

Kaakinen, M; Huttunen, S; Paavolainen, L; Marjomäki, V; Heikkilä, J; Eklund, L

2014-01-01

Phase-contrast illumination is simple and most commonly used microscopic method to observe nonstained living cells. Automatic cell segmentation and motion analysis provide tools to analyze single cell motility in large cell populations. However, the challenge is to find a sophisticated method that is sufficiently accurate to generate reliable results, robust to function under the wide range of illumination conditions encountered in phase-contrast microscopy, and also computationally light for efficient analysis of large number of cells and image frames. To develop better automatic tools for analysis of low magnification phase-contrast images in time-lapse cell migration movies, we investigated the performance of cell segmentation method that is based on the intrinsic properties of maximally stable extremal regions (MSER). MSER was found to be reliable and effective in a wide range of experimental conditions. When compared to the commonly used segmentation approaches, MSER required negligible preoptimization steps thus dramatically reducing the computation time. To analyze cell migration characteristics in time-lapse movies, the MSER-based automatic cell detection was accompanied by a Kalman filter multiobject tracker that efficiently tracked individual cells even in confluent cell populations. This allowed quantitative cell motion analysis resulting in accurate measurements of the migration magnitude and direction of individual cells, as well as characteristics of collective migration of cell groups. Our results demonstrate that MSER accompanied by temporal data association is a powerful tool for accurate and reliable analysis of the dynamic behaviour of cells in phase-contrast image sequences. These techniques tolerate varying and nonoptimal imaging conditions and due to their relatively light computational requirements they should help to resolve problems in computationally demanding and often time-consuming large-scale dynamical analysis of cultured cells. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

PubMed

Akil, Mustafa; Bicer, Mursel; Kilic, Mehmet; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

2011-03-01

There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p < 0.05). The levels in group 4 were lower than those in groups 1 and 2 but higher than the levels in group 3 (p < 0.05). The lowest liver glycogen levels were obtained in group 3 (p < 0.05). Results of the study indicate that liver glycogen levels that decrease in acute swimming exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance.

Biomolecular Analysis Capability for Cellular and Omics Research on the International Space Station

NASA Technical Reports Server (NTRS)

Guinart-Ramirez, Y.; Cooley, V. M.; Love, J. E.

2016-01-01

International Space Station (ISS) assembly complete ushered a new era focused on utilization of this state-of-the-art orbiting laboratory to advance science and technology research in a wide array of disciplines, with benefits to Earth and space exploration. ISS enabling capability for research in cellular and molecular biology includes equipment for in situ, on-orbit analysis of biomolecules. Applications of this growing capability range from biomedicine and biotechnology to the emerging field of Omics. For example, Biomolecule Sequencer is a space-based miniature DNA sequencer that provides nucleotide sequence data for entire samples, which may be used for purposes such as microorganism identification and astrobiology. It complements the use of WetLab-2 SmartCycler"TradeMark", which extracts RNA and provides real-time quantitative gene expression data analysis from biospecimens sampled or cultured onboard the ISS, for downlink to ground investigators, with applications ranging from clinical tissue evaluation to multigenerational assessment of organismal alterations. And the Genes in Space-1 investigation, aimed at examining epigenetic changes, employs polymerase chain reaction to detect immune system alterations. In addition, an increasing assortment of tools to visualize the subcellular distribution of tagged macromolecules is becoming available onboard the ISS. For instance, the NASA LMM (Light Microscopy Module) is a flexible light microscopy imaging facility that enables imaging of physical and biological microscopic phenomena in microgravity. Another light microscopy system modified for use in space to image life sciences payloads is initially used by the Heart Cells investigation ("Effects of Microgravity on Stem Cell-Derived Cardiomyocytes for Human Cardiovascular Disease Modeling and Drug Discovery"). Also, the JAXA Microscope system can perform remotely controllable light, phase-contrast, and fluorescent observations. And upcoming confocal microscopy capability will allow for optical sectioning of biological tissues to determine microanatomical localization of biomarkers. Furthermore, NASA's geneLAB effort addresses integration of genomic, epigenomic, transcriptomic, proteomic and metabolomic datasets, by applying an innovative open source science platform for multi-investigator high throughput utilization of the ISS. In sum, the expanding ISS capability for analysis of biomolecules is enabling innovative research in a broad spectrum of areas such as cellular and molecular biology, biotechnology, tissue engineering, biomedicine, and Omics, providing manifold benefits for humanity.

Coherent imaging with incoherent light in digital holographic microscopy

NASA Astrophysics Data System (ADS)

Chmelik, Radim

2012-01-01

Digital holographic microscope (DHM) allows for imaging with a quantitative phase contrast. In this way it becomes an important instrument, a completely non-invasive tool for a contrast intravital observation of living cells and a cell drymass density distribution measurement. A serious drawback of current DHMs is highly coherent illumination which makes the lateral resolution worse and impairs the image quality by a coherence noise and a parasitic interference. An uncompromising solution to this problem can be found in the Leith concept of incoherent holography. An off-axis hologram can be formed with arbitrary degree of light coherence in systems equipped with an achromatic interferometer and thus the resolution and the image quality typical for an incoherent-light wide-field microscopy can be achieved. In addition, advanced imaging modes based on limited coherence can be utilized. The typical example is a coherence-gating effect which provides a finite axial resolution and makes DHM image similar to that of a confocal microscope. These possibilities were described theoretically using the formalism of three-dimensional coherent transfer functions and proved experimentally by the coherence-controlled holographic microscope which is DHM based on the Leith achromatic interferometer. Quantitative-phase-contrast imaging is demonstrated with incoherent light by the living cancer cells observation and their motility evaluation. The coherence-gating effect was proved by imaging of model samples through a scattering layer and living cells inside an opalescent medium.

Characterisation of a resolution enhancing image inversion interferometer.

PubMed

Wicker, Kai; Sindbert, Simon; Heintzmann, Rainer

2009-08-31

Image inversion interferometers have the potential to significantly enhance the lateral resolution and light efficiency of scanning fluorescence microscopes. Self-interference of a point source's coherent point spread function with its inverted copy leads to a reduction in the integrated signal for off-axis sources compared to sources on the inversion axis. This can be used to enhance the resolution in a confocal laser scanning microscope. We present a simple image inversion interferometer relying solely on reflections off planar surfaces. Measurements of the detection point spread function for several types of light sources confirm the predicted performance and suggest its usability for scanning confocal fluorescence microscopy.

Detection of fungal hyphae using smartphone and pocket magnifier: going cellular.

PubMed

Agarwal, Tushar; Bandivadekar, Pooja; Satpathy, Gita; Sharma, Namrata; Titiyal, Jeewan S

2015-03-01

The aim of this study was to detect fungal hyphae in a corneal scraping sample using a cost-effective assembly of smartphone and pocket magnifier. In this case report, a tissue sample was obtained by conventional corneal scraping from a clinically suspicious case of mycotic keratitis. The smear was stained with Gram stain, and a 10% potassium hydroxide mount was prepared. It was imaged using a smartphone coupled with a compact pocket magnifier and integrated light-emitting diode assembly at point-of-care. Photographs of multiple sections of slides were viewed using smartphone screen and pinch-to-zoom function. The same slides were subsequently screened under a light microscope by an experienced microbiologist. The scraping from the ulcer was also inoculated on blood agar and Sabouraud dextrose agar. Smartphone-based digital imaging revealed the presence of gram-positive organism with hyphae. Examination under a light microscope also yielded similar findings. Fusarium was cultured from the corneal scraping, confirming the diagnosis of mycotic keratitis. The patient responded to topical 5% natamycin therapy, with resolution of the ulcer after 4 weeks. Smartphones can be successfully used as novel point-of-care, cost-effective, reliable microscopic screening tools.

Photonic Microhand with Autonomous Action.

PubMed

Martella, Daniele; Nocentini, Sara; Nuzhdin, Dmitry; Parmeggiani, Camilla; Wiersma, Diederik S

2017-11-01

Grabbing and holding objects at the microscale is a complex function, even for microscopic living animals. Inspired by the hominid-type hand, a microscopic equivalent able to catch microelements is engineered. This microhand is light sensitive and can be either remotely controlled by optical illumination or can act autonomously and grab small particles on the basis of their optical properties. Since the energy is delivered optically, without the need for wires or batteries, the artificial hand can be shrunk down to the micrometer scale. Soft material is used, in particular, a custom-made liquid-crystal network that is patterned by a photolithographic technique. The elastic reshaping properties of this material allow finger movement, using environmental light as the only energy source. The hand can be either controlled externally (via the light field), or else the conditions in which it autonomously grabs a particle in its vicinity can be created. This microrobot has the unique feature that it can distinguish between particles of different colors and gray levels. The realization of this autonomous hand constitutes a crucial element in the development of microscopic creatures that can perform tasks without human intervention and self-organized automation at the micrometer scale. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aligning Arrays of Lenses and Single-Mode Optical Fibers

NASA Technical Reports Server (NTRS)

Liu, Duncan

2004-01-01

A procedure now under development is intended to enable the precise alignment of sheet arrays of microscopic lenses with the end faces of a coherent bundle of as many as 1,000 single-mode optical fibers packed closely in a regular array (see Figure 1). In the original application that prompted this development, the precise assembly of lenses and optical fibers serves as a single-mode spatial filter for a visible-light nulling interferometer. The precision of alignment must be sufficient to limit any remaining wavefront error to a root-mean-square value of less than 1/10 of a wavelength of light. This wavefront-error limit translates to requirements to (1) ensure uniformity of both the lens and fiber arrays, (2) ensure that the lateral distance from the central axis of each lens and the corresponding optical fiber is no more than a fraction of a micron, (3) angularly align the lens-sheet planes and the fiber-bundle end faces to within a few arc seconds, and (4) axially align the lenses and the fiber-bundle end faces to within tens of microns of the focal distance. Figure 2 depicts the apparatus used in the alignment procedure. The beam of light from a Zygo (or equivalent) interferometer is first compressed by a ratio of 20:1 so that upon its return to the interferometer, the beam will be magnified enough to enable measurement of wavefront quality. The apparatus includes relay lenses that enable imaging of the arrays of microscopic lenses in a charge-coupled-device (CCD) camera that is part of the interferometer. One of the arrays of microscopic lenses is mounted on a 6-axis stage, in proximity to the front face of the bundle of optical fibers. The bundle is mounted on a separate stage. A mirror is attached to the back face of the bundle of optical fibers for retroreflection of light. When a microscopic lens and a fiber are aligned with each other, the affected portion of the light is reflected back by the mirror, recollimated by the microscopic lens, transmitted through the relay lenses and the beam compressor/expander, then split so that half goes to a detector and half to the interferometer. The output of the detector is used as a feedback control signal for the six-axis stage to effect alignment.

Finding the patterns in complex specimens by improving the acquisition and analysis of x-ray spectromicroscopy data

NASA Astrophysics Data System (ADS)

Lerotic, Mirna

Soft x-ray spectromicroscopy provides spectral data on the chemical speciation of light elements at sub-100 nanometer spatial resolution. The high resolution imaging places a strong demand on the microscope stability and on the reproducibility of the scanned image field, and the volume of data necessitates the need for improved data analysis methods. This dissertation concerns two developments in extending the capability of soft x-ray transmission microscopes to carry out studies of chemical speciation at high spatial resolution. One development involves an improvement in x-ray microscope instrumentation: a new Stony Brook scanning transmission x-ray microscope which incorporates laser interferometer feedback in scanning stage positions. The interferometer is used to control the position between the sample and focusing optics, and thus improve the stability of the system. A second development concerns new analysis methods for the study of chemical speciation of complex specimens, such as those in biological and environmental science studies. When all chemical species in a specimen are known and separately characterized, existing approaches can be used to measure the concentration of each component at each pixel. In other cases (such as often occur in biology or environmental science), where the specimen may be too complicated or provide at least some unknown spectral signatures, other approaches must be used. We describe here an approach that uses principal component analysis (similar to factor analysis) to orthogonalize and noise-filter spectromicroscopy data. We then use cluster analysis (a form of unsupervised pattern matching) to classify pixels according to spectral similarity, to extract representative, cluster-averaged spectra with good signal-to-noise ratio, and to obtain gradations of concentration of these representative spectra at each pixel. The method is illustrated with a simulated data set of organic compounds, and a mixture of lutetium in hematite used to understand colloidal transport properties of radionuclides. Also, we describe here an extension of that work employing an angle distance measure; this measure provides better classification based on spectral signatures alone in specimens with significant thickness variations. The method is illustrated using simulated data, and also to examine sporulation in the bacterium Clostridium sp.

A study of the treatment of cutaneous fungal infection in animal model using photoactivated composite of methylene blue and gold nanoparticle.

PubMed

Tawfik, Abeer Attia; Noaman, Islam; El-Elsayyad, Hasan; El-Mashad, Noha; Soliman, Mona

2016-09-01

Onychomycosis is a widespread public health problem, in which T. rubrum and T. mentagrophytes is the commenest causative organisms. Current medical therapy has many drawbacks and side effects. Methylene blue (m.b) photodynamic therapy (pdt) proved efficacy but with lengthy sessions. Optimizing methylene blue photodynamic therapy by combination of methylene blue photosensitizer and gold nanoparticles (aunps) in a composite as gold nanoparticles are efficient delivery systems and efficient enhancers of photosensitizers for antifungal photodynamic therapy. Eighty newzealand rabbit (Oryctolagus cuniculus) were used and categorized in eight equal groups as follows; healthy and infection control, composite photodynamic therapy and five comparative groups. Photodynamic therapy was initiated at day three to five post inoculation, for four sessions forty eight hours apart. Each group divided and light exposure at two fluencies; 80J and 100J. All groups were investigated macroscopically and microscopically (histopathology and scanning electron microscope) also flowcytometry assessment for cell death and X-ray analysis for gold nanoparticles accumulation in brain and liver tissues were determined. Recovery from infection approaching 96% in gold nanoparticles+light group, around 40% in methylene blue photodynamic therapy and 34% in composite photodynamic therapy. The observed findings confirmed by apparent decrease of apoptosis, however small amounts of gold nanoparticles detected in brain and liver. Light stimulated gold nanoparticles is a promising tool in treatment of onychomycosis. Copyright © 2016 Elsevier B.V. All rights reserved.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity

PubMed Central

Frost, William N.; Wang, Jean; Brandon, Christopher J.

2007-01-01

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations. PMID:17306887

Detection of microstructural defects in chalcopyrite Cu(In,Ga)Se2 solar cells by spectrally-filtered electroluminescence

NASA Astrophysics Data System (ADS)

Skvarenina, L.; Gajdos, A.; Macku, R.; Skarvada, P.

2017-12-01

The aim of this research is to detect and localize microstructural defects by using an electrically excited light emission from a forward/reverse-bias stressed pn-junction in thin-film Cu(In; Ga)Se2 solar cells with metal wrap through architecture. A different origin of the local light emission from intrinsic/extrinsic imperfections in these chalcopyrite-based solar cells can be distinguished by a spectrally-filtered electroluminescence mapping. After a light emission mapping and localization of the defects in a macro scale is performed a micro scale exploration of the solar cell surface by a scanning electron microscope which follows the particular defects obtained by an electroluminescence. In particular, these macroscopic/microscopic examinations are performed independently, then the searching of the corresponding defects in the micro scale is rather difficult due to a diffused light emission obtained from the macro scale localization. Some of the defects accompanied by a highly intense light emission very often lead to a strong local overheating. Therefore, the lock-in infrared thermography is also performed along with an electroluminescence mapping.

Two-way communication with neural networks in vivo using focused light

PubMed Central

Wilson, Nathan R.; Schummers, James; Runyan, Caroline A.; Yan, Sherry; Chen, Robert F.; Deng, Yuting; Sur, Mriganka

2014-01-01

Neuronal networks process information in a distributed, spatially heterogeneous fashion that transcends the layout of electrodes. In contrast, directed and steerable light offers the potential to engage specific cells on demand. We present a unified framework for adapting microscopes to use light for simultaneous in vivo stimulation and recording of cells at fine spatiotemporal resolutions. We utilize straightforward optics to lock onto networks in vivo, steer light to activate circuit elements, and simultaneously record from other cells. We then actualize this “free” augmentation on both an “open” two-photon microscope, and a leading commercial one. Following this protocol, setup of the system takes a few days and the result is a non-invasive interface to brain dynamics based on directed light, at a network resolution that was not previously possible and which will further improve with the rapid advance in development of optical reporters and effectors. This protocol is for physiologists who are competent with computers and wish to extend hardware and software to interface more fluidly with neuronal networks. PMID:23702834

Structural refinement, band-gap analysis and optical properties of GdAlO3 nanophosphors influenced by Dy3+ ion concentrations for white light emitting device applications

NASA Astrophysics Data System (ADS)

Jisha, P. K.; Naik, Ramachandra; Prashantha, S. C.; Nagaswarupa, H. P.; Nagabhushana, H.; Basavaraj, R. B.; Sharma, S. C.; Prasad, Daruka

2016-04-01

Nanosized GdAlO3 phosphors activated with Dy3+ were prepared by a combustion method. Synthesized phosphors were calcined at 1000 °C for 3 h in order to achieve crystallinity. Powder x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was used to characterize the prepared product. The orthorhombic phase was observed in the XRD pattern. The particle size of the samples was calculated as around 25 nm. The SEM images show an irregular shape of the prepared nanophosphor. Functional groups of the phosphors were examined by Fourier transform infrared (FTIR) spectroscopy. Photoluminescence (PL) properties of Dy3+ doped GdAlO3 for near-ultraviolet excitation (352 nm) were studied in order to investigate the possibility of its use in white light emitting device applications. Judd-Ofelt intensity parameters, radiative transition rate (A T) and radiative lifetimes (τ rad) were evaluated from the emission spectrum by adopting a standard procedure. The Commission International de l’Eclairage (CIE) color coordinates and correlated color temperature (CCT) are studied for the optimized phosphor. It is found that the color coordinates of Dy3+ doped GdAlO3 powders fall in the white region of the CIE diagram, and the average CCT value was found to be about 6276 K. Therefore, the present phosphor is highly useful for display applications.

Polarization Change in Face-Centered Cubic Opal Films

NASA Astrophysics Data System (ADS)

Wolff, Christian; Romanov, Sergei; Küchenmeister, Jens; Peschel, Ulf; Busch, Kurt

2011-10-01

Artificial opals are a popular platform for investigating fundamental properties of Photonic Crystals (PhC). In this work, we provide a theoretical analysis of polarization-resolved transmission experiments through thin opal films. Despite the full cubic symmetry of the PhC, this system provides a very efficient mechanism for manipulating the polarization state of light. Based on band structure calculations and Bloch mode analysis, we find that this effect closely resembles classical birefringence. Due to the cubic symmetry, however, a description using tensorial quantities is not possible. This indicates fundamental limitations of effective material models for Photonic Crystals and demonstrates the importance of accurately modelling the microscopic geometry of such systems.

Prochloron research

NASA Technical Reports Server (NTRS)

Lewin, R. A.; Cheng, L.

1983-01-01

The purpose was to prepare Prochloron photosynthetic membranes for the isolation of the two major chlorophyll-proteins, the P700-chlorophyll a-protein and the light-harvesting chlorophyll a/b-protein, using SDS-polyacrylamide gel electrophoresis. The prepared proteins (purified) were examined for their cross-reactivity to polyclonal antibodies prepared from higher plant proteins. In addition, material was prepared for electron microscopy, and isolation of the DNA for determination of its general complexity (COT analysis) and similarity to barley chloroplast DNA and Anabaena DNA by using restriction-endonuclease analysis. Kleinschmidt spreads of the DNA were in the electron microscope to identify and measure the extent and size of the circlar DNA.

Sequential processing of quantitative phase images for the study of cell behaviour in real-time digital holographic microscopy.

PubMed

Zikmund, T; Kvasnica, L; Týč, M; Křížová, A; Colláková, J; Chmelík, R

2014-11-01

Transmitted light holographic microscopy is particularly used for quantitative phase imaging of transparent microscopic objects such as living cells. The study of the cell is based on extraction of the dynamic data on cell behaviour from the time-lapse sequence of the phase images. However, the phase images are affected by the phase aberrations that make the analysis particularly difficult. This is because the phase deformation is prone to change during long-term experiments. Here, we present a novel algorithm for sequential processing of living cells phase images in a time-lapse sequence. The algorithm compensates for the deformation of a phase image using weighted least-squares surface fitting. Moreover, it identifies and segments the individual cells in the phase image. All these procedures are performed automatically and applied immediately after obtaining every single phase image. This property of the algorithm is important for real-time cell quantitative phase imaging and instantaneous control of the course of the experiment by playback of the recorded sequence up to actual time. Such operator's intervention is a forerunner of process automation derived from image analysis. The efficiency of the propounded algorithm is demonstrated on images of rat fibrosarcoma cells using an off-axis holographic microscope. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Characterization and identification of microorganisms by FT-IR microspectrometry

NASA Astrophysics Data System (ADS)

Ngo-Thi, N. A.; Kirschner, C.; Naumann, D.

2003-12-01

We report on a novel FT-IR approach for microbial characterization/identification based on a light microscope coupled to an infrared spectrometer which offers the possibility to acquire IR-spectra of microcolonies containing only few hundred cells. Microcolony samples suitable for FT-IR microspectroscopic measurements were obtained by a replica technique with a stamping device that transfers spatially accurate cells of microcolonies growing on solid culture plates to a special, IR-transparent or reflecting stamping plate. High quality spectra could be recorded either by applying the transmission/absorbance or the reflectance/absorbance mode of the infrared microscope. Signal to noise ratios higher than 1000 were obtained for microcolonies as small as 40 μm in diameter. Reproducibility levels were established that allowed species and strain identification. The differentiation and classification capacity of the FT-IR microscopic technique was tested for different selected microorganisms. Cluster and factor analysis methods were used to evaluate the complex spectral data. Excellent discrimination between bacteria and yeasts, and at the same time Gram-negative and Gram-positive bacterial strains was obtained. Twenty-two selected strains of different species within the genus Staphylococcus were repetitively measured and could be grouped into correct species cluster. Moreover, the results indicated that the method allows also identifications at the subspecies level. Additionally, the new approach allowed spectral mapping analysis of single colonies which provided spatially resolved characterization of growth heterogeneity within complex microbial populations such as colonies.

Spatiotemporal polarization modulation microscopy with a microretarder array

NASA Astrophysics Data System (ADS)

Ding, Changqin; Ulcickas, James R. W.; Simpson, Garth J.

2018-02-01

A patterned microretarder array positioned in the rear conjugate plane of a microscope enables rapid polarizationdependent nonlinear optical microscopy. The pattern introduced to the array results in periodic modulation of the polarization-state of the incident light as a function of position within the field of view with no moving parts or active control. Introduction of a single stationary optical element and a fixed polarizer into the beam of a nonlinear optical microscope enabled nonlinear optical tensor recovery, which informs on local structure and orientation. Excellent agreement was observed between the measured and predicted second harmonic generation (SHG) of z-cut quartz, selected as a test system with well-established nonlinear optical properties. Subsequent studies of spatially varying samples further support the general applicability of this relatively simple strategy for detailed polarization analysis in both conventional and nonlinear optical imaging of structurally diverse samples.

Aberration correction in wide-field fluorescence microscopy by segmented-pupil image interferometry.

PubMed

Scrimgeour, Jan; Curtis, Jennifer E

2012-06-18

We present a new technique for the correction of optical aberrations in wide-field fluorescence microscopy. Segmented-Pupil Image Interferometry (SPII) uses a liquid crystal spatial light modulator placed in the microscope's pupil plane to split the wavefront originating from a fluorescent object into an array of individual beams. Distortion of the wavefront arising from either system or sample aberrations results in displacement of the images formed from the individual pupil segments. Analysis of image registration allows for the local tilt in the wavefront at each segment to be corrected with respect to a central reference. A second correction step optimizes the image intensity by adjusting the relative phase of each pupil segment through image interferometry. This ensures that constructive interference between all segments is achieved at the image plane. Improvements in image quality are observed when Segmented-Pupil Image Interferometry is applied to correct aberrations arising from the microscope's optical path.

Spectrally And Temporally Resolved Low-Light Level Video Microscopy

NASA Astrophysics Data System (ADS)

Wampler, John E.; Furukawa, Ruth; Fechheimer, Marcus

1989-12-01

The IDG law-light video microscope system was designed to aid studies of localization of subcellular luminescence sources and stimulus/response coupling in single living cells using luminescent probes. Much of the motivation for design of this instrument system came from the pioneering efforts of Dr. Reynolds (Reynolds, Q. Rev. Biophys. 5, 295-347; Reynolds and Taylor, Bioscience 30, 586-592) who showed the value of intensified video camera systems for detection and localizion of fluorescence and bioluminescence signals from biological tissues. Our instrument system has essentially two roles, 1) localization and quantitation of very weak bioluminescence signals and 2) quantitation of intracellular environmental characteristics such as pH and calcium ion concentrations using fluorescent and bioluminescent probes. The instrument system exhibits over one million fold operating range allowing visualization and enhancement of quantum limited images with quantum limited response, spectral analysis of fluorescence signals, and transmitted light imaging. The computer control of the system implements rapid switching between light regimes, spatially resolved spectral scanning, and digital data processing for spectral shape analysis and for detailed analysis of the statistical distribution of single cell measurements. The system design and software algorithms used by the system are summarized. These design criteria are illustrated with examples taken from studies of bioluminescence, applications of bioluminescence to study developmental processes and gene expression in single living cells, and applications of fluorescent probes to study stimulus/response coupling in living cells.

Dissociation of β-Sheet Stacking of Amyloid β Fibrils by Irradiation of Intense, Short-Pulsed Mid-infrared Laser.

PubMed

Kawasaki, Takayasu; Yaji, Toyonari; Ohta, Toshiaki; Tsukiyama, Koichi; Nakamura, Kazuhiro

2018-02-05

Structure of amyloid β (Aβ) fibrils is rigidly stacked by β-sheet conformation, and the fibril state of Aβ is profoundly related to pathogenesis of Alzheimer's disease (AD). Although mid-infrared light has been used for various biological researches, it has not yet been known whether the infrared light changes the fibril structure of Aβ. In this study, we tested the effect of irradiation of intense mid-infrared light from a free-electron laser (FEL) targeting the amide bond on the reduction of β-sheet content in Aβ fibrils. The FEL reduced entire contents of proteins exhibiting β-sheet structure in brain sections from AD model mice, as shown by synchrotron-radiation infrared microscopy analysis. Since Aβ 1-42 fibril absorbed a considerable FEL energy at amide I band (6.17 μm), we irradiated the FEL at 6.17 μm and found that β-sheet content of naked Aβ 1-42 fibril was decreased using infrared microscopic analysis. Consistent with the decrease in the β-sheet content, Congo-red signal is decreased after the irradiation to Aβ 1-42 fibril. Furthermore, electron microscopy analysis revealed that morphologies of the fibril and proto-fibril were largely changed after the irradiation. Thus, mid-infrared light dissociates β-sheet structure of Aβ fibrils, which justifies exploration of possible laser-based therapy for AD.

Control and acquisition systems for new scanning transmission x-ray microscopes at Advanced Light Source (abstract)

NASA Astrophysics Data System (ADS)

Tyliszczak, T.; Hitchcock, P.; Kilcoyne, A. L. D.; Ade, H.; Hitchcock, A. P.; Fakra, S.; Steele, W. F.; Warwick, T.

2002-03-01

Two new scanning x-ray transmission microscopes are being built at beamline 5.3.2 and beamline 7.0 of the Advanced Light Source that have novel aspects in their control and acquisition systems. Both microscopes use multiaxis laser interferometry to improve the precision of pixel location during imaging and energy scans as well as to remove image distortions. Beam line 5.3.2 is a new beam line where the new microscope will be dedicated to studies of polymers in the 250-600 eV energy range. Since this is a bending magnet beam line with lower x-ray brightness than undulator beam lines, special attention is given to the design not only to minimize distortions and vibrations but also to optimize the controls and acquisition to improve data collection efficiency. 5.3.2 microscope control and acquisition is based on a PC computer running WINDOWS 2000. All mechanical stages are moved by stepper motors with rack mounted controllers. A dedicated counter board is used for counting and timing and a multi-input/output board is used for analog acquisition and control of the focusing mirror. A three axis differential laser interferometer is being used to improve stability and precision by careful tracking of the relative positions of the sample and zone plate. Each axis measures the relative distance between a mirror placed on the sample stage and a mirror attached to the zone plate holder. Agilent Technologies HP 10889A servo-axis interferometer boards are used. While they were designed to control servo motors, our tests show that they can be used to directly control the piezo stage. The use of the interferometer servo-axis boards provides excellent point stability for spectral measurements. The interferometric feedback also provides active vibration isolation which reduces deleterious impact of mechanical vibrations up to 20-30 Hz. It also can improve the speed and precision of image scans. Custom C++ software has been written to provide user friendly control of the microscope and integration with visual light microscopy indexing of the samples. The beam line 7.0 microscope upgrade is a new design which will replace the existing microscope. The design is similar to that of beam line 5.3.2, including interferometric position encoding. However the acquisition and control is based on VXI systems, a Sun computer, and LABVIEW™ software. The main objective of the BL 7.0 microscope upgrade is to achieve precise image scans at very high speed (pixel dwells as short as 10 μs) to take full advantage of the high brightness of the 7.0 undulator beamline. Results of tests and a discussion of the benefits of our scanning microscope designs will be presented.

Micro axial tomography: A miniaturized, versatile stage device to overcome resolution anisotropy in fluorescence light microscopy

NASA Astrophysics Data System (ADS)

Staier, Florian; Eipel, Heinz; Matula, Petr; Evsikov, Alexei V.; Kozubek, Michal; Cremer, Christoph; Hausmann, Michael

2011-09-01

With the development of novel fluorescence techniques, high resolution light microscopy has become a challenging technique for investigations of the three-dimensional (3D) micro-cosmos in cells and sub-cellular components. So far, all fluorescence microscopes applied for 3D imaging in biosciences show a spatially anisotropic point spread function resulting in an anisotropic optical resolution or point localization precision. To overcome this shortcoming, micro axial tomography was suggested which allows object tilting on the microscopic stage and leads to an improvement in localization precision and spatial resolution. Here, we present a miniaturized device which can be implemented in a motor driven microscope stage. The footprint of this device corresponds to a standard microscope slide. A special glass fiber can manually be adjusted in the object space of the microscope lens. A stepwise fiber rotation can be controlled by a miniaturized stepping motor incorporated into the device. By means of a special mounting device, test particles were fixed onto glass fibers, optically localized with high precision, and automatically rotated to obtain views from different perspective angles under which distances of corresponding pairs of objects were determined. From these angle dependent distance values, the real 3D distance was calculated with a precision in the ten nanometer range (corresponding here to an optical resolution of 10-30 nm) using standard microscopic equipment. As a proof of concept, the spindle apparatus of a mature mouse oocyte was imaged during metaphase II meiotic arrest under different perspectives. Only very few images registered under different rotation angles are sufficient for full 3D reconstruction. The results indicate the principal advantage of the micro axial tomography approach for many microscopic setups therein and also those of improved resolutions as obtained by high precision localization determination.

Optical Coherence Tomography–Enhanced Microlaryngoscopy: Preliminary Report of a Noncontact Optical Coherence Tomography System Integrated With a Surgical Microscope

PubMed Central

Vokes, David E.; Jackson, Ryan; Guo, Shuguang; Perez, Jorge A.; Su, Jianping; Ridgway, James M.; Armstrong, William B.; Chen, Zhongping; Wong, Brian J. F.

2014-01-01

Objectives Optical coherence tomography (OCT) is a new imaging modality that uses near-infrared light to produce cross-sectional images of tissue with a resolution approaching that of light microscopy. We have previously reported use of OCT imaging of the vocal folds (VFs) during direct laryngoscopy with a probe held in contact or near-contact with the VFs. This aim of this study was to develop and evaluate a novel OCT system integrated with a surgical microscope to allow hands-free OCT imaging of the VFs, which could be performed simultaneously with microscopic visualization. Methods We performed a prospective evaluation of a new method of acquiring OCT images of the VFs. Results An OCT system was successfully integrated with a surgical microscope to permit noncontact OCT imaging of the VFs of 10 patients. With this novel device we were able to identify VF epithelium and lamina propria; however, the resolution was reduced compared to that achieved with the standard contact or near-contact OCT. Conclusions Optical coherence tomography is able to produce high-resolution images of vocal fold mucosa to a maximum depth of 1.6 mm. It may be used in the diagnosis of VF lesions, particularly early squamous cell carcinoma, in which OCT can show disruption of the basement membrane. Mounting the OCT device directly onto the operating microscope allows hands-free noncontact OCT imaging and simultaneous conventional microscopic visualization of the VFs. However, the lateral resolution of the OCT microscope system is 50 µm, in contrast to the conventional handheld probe system (10 µm). Although such images at this resolution are still useful clinically, improved resolution would enhance the system’s performance, potentially enabling real-time OCT-guided microsurgery of the larynx. PMID:18700431

78 FR 64916 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-30

...., light to heat), crystallization, melting, phase transformations, fracture, and other dynamic events. The... Sciences University, 1120 15th Street, Augusta, GA 30912. Instrument: Imaging System/Digital Microscope... the instrument include fast wavelength change, a dichromotome system, and two different light sources...

Coherent scattering of near-resonant light by a dense, microscopic cloud of cold two-level atoms: Experiment versus theory

NASA Astrophysics Data System (ADS)

Jennewein, Stephan; Brossard, Ludovic; Sortais, Yvan R. P.; Browaeys, Antoine; Cheinet, Patrick; Robert, Jacques; Pillet, Pierre

2018-05-01

We measure the coherent scattering of low-intensity, near-resonant light by a cloud of laser-cooled two-level rubidium atoms with a size comparable to the wavelength of light. We isolate a two-level atomic structure by applying a 300-G magnetic field. We measure both the temporal and the steady-state coherent optical response of the cloud for various detunings of the laser and for atom numbers ranging from 5 to 100. We compare our results to a microscopic coupled-dipole model and to a multimode, paraxial Maxwell-Bloch model. In the low-intensity regime, both models are in excellent agreement, thus validating the Maxwell-Bloch model. Comparing to the data, the models are found in very good agreement for relatively low densities (n /k3≲0.1 ), while significant deviations start to occur at higher density. This disagreement indicates that light scattering in dense, cold atomic ensembles is still not quantitatively understood, even in pristine experimental conditions.

Portable and cost-effective pixel super-resolution on-chip microscope for telemedicine applications.

PubMed

Bishara, Waheb; Sikora, Uzair; Mudanyali, Onur; Su, Ting-Wei; Yaglidere, Oguzhan; Luckhart, Shirley; Ozcan, Aydogan

2011-01-01

We report a field-portable lensless on-chip microscope with a lateral resolution of <1 μm and a large field-of-view of ~24 mm(2). This microscope is based on digital in-line holography and a pixel super-resolution algorithm to process multiple lensfree holograms and obtain a single high-resolution hologram. In its compact and cost-effective design, we utilize 23 light emitting diodes butt-coupled to 23 multi-mode optical fibers, and a simple optical filter, with no moving parts. Weighing only ~95 grams, we demonstrate the performance of this field-portable microscope by imaging various objects including human malaria parasites in thin blood smears.

Macro-microscopic anatomy: obtaining a composite view of barrier zone formation in Acer saccharum

Treesearch

Kenneth Dudzik

1988-01-01

The technique for constructing a montage of large wood sections cut on a sliding microtome is discussed. Briefly, the technique involves photographing many serial micrographs in a pattern under a light microscope similar to the way flight lines are run in aerial photography. Assembly of the resulting overlapping photographs requires careful trimming. A composite of...

Telepathology. Long-distance diagnosis.

PubMed

Weinstein, R S; Bloom, K J; Rozek, L S

1989-04-01

Telepathology is defined as the practice of pathology at a distance, by visualizing an image on a video monitor rather than viewing a specimen directly through a microscope. Components of a telepathology system include the following: (1) a workstation equipped with a high-resolution video camera attached to a remote-controlled light microscope; (2) a pathologist workstation incorporating controls for manipulating the robotic microscope as well as a high-resolution video monitor; and (3) a telecommunications link. Progress has been made in designing and constructing telepathology workstations and fully motorized, computer-controlled light microscopes suitable for telepathology. In addition, components such as video signal digital encoders and decoders that produce remarkably stable, high-color fidelity, and high-resolution images have been incorporated into the workstations. Resolution requirements for the video microscopy component of telepathology have been formally examined in receiver operator characteristic (ROC) curve analyses. Test-of-concept demonstrations have been completed with the use of geostationary satellites as the broadband communication linkages for 750-line resolution video. Potential benefits of telepathology include providing a means of conveniently delivering pathology services in real-time to remote sites or underserviced areas, time-sharing of pathologists' services by multiple institutions, and increasing accessibility to specialty pathologists.

Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope

PubMed Central

Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

2015-01-01

We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy. PMID:26819828

Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

PubMed

Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

2016-01-01

We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy.

Sub-micrometer resolution proximity X-ray microscope with digital image registration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chkhalo, N. I.; Salashchenko, N. N.; Sherbakov, A. V., E-mail: SherbakovAV@ipm.sci-nnov.ru

A compact laboratory proximity soft X-ray microscope providing submicrometer spatial resolution and digital image registration is described. The microscope consists of a laser-plasma soft X-ray radiation source, a Schwarzschild objective to illuminate the test sample, and a two-coordinate detector for image registration. Radiation, which passes through the sample under study, generates an absorption image on the front surface of the detector. Optical ceramic YAG:Ce was used to convert the X-rays into visible light. An image was transferred from the scintillator to a charge-coupled device camera with a Mitutoyo Plan Apo series lens. The detector’s design allows the use of lensesmore » with numerical apertures of NA = 0.14, 0.28, and 0.55 without changing the dimensions and arrangement of the elements of the device. This design allows one to change the magnification, spatial resolution, and field of view of the X-ray microscope. A spatial resolution better than 0.7 μm and an energy conversion efficiency of the X-ray radiation with a wavelength of 13.5 nm into visible light collected by the detector of 7.2% were achieved with the largest aperture lens.« less

ZnO/TiO2 nanocomposite rods synthesized by microwave-assisted method for humidity sensor application

NASA Astrophysics Data System (ADS)

Ashok, CH.; Venkateswara Rao, K.

2014-12-01

The nanocomposite rods shows well known properties compared with nano structured materials for various applications like light-emitting diodes, electron field emitters, solar cells, optoelectronics, sensors, transparent conductors and fabrication of nano devices. Present paper investigates the properties of ZnO/TiO2 nanocomposite rods. The bi component of ZnO/TiO2 nanocomposite rods was synthesized by microwave-assisted method which is very simple, rapid and uniform in heating. The frequency of microwaves 2.45 GHz was used and temperature maintained 180 °C. Zinc acetate and titanium isopropoxide precursors were used in the preparation. The obtained ZnO/TiO2 nanocomposite rods were annealed at 500 °C and 600 °C. ZnO/TiO2 nanocomposite rods have been characterized by X-ray Diffraction (XRD) for average crystallite size and phase of the composite material, Particle Size Analyser (PSA) for average particle size, Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) for morphology study, Energy Dispersive X-ray Spectrometry (EDX) for elemental analysis, and Thermal Gravimetric and Differential Thermal Analysis (TG-DTA) for thermal property.

Evaluation of sperm motility with CASA-Mot: which factors may influence our measurements?

PubMed

Yeste, Marc; Bonet, Sergi; Rodríguez-Gil, Joan E; Rivera Del Álamo, Maria M

2018-03-14

Computer-aided sperm analysis (CASA) is now routinely used in IVF clinics, animal breeding centres and research laboratories. Although CASA provides a more objective way to evaluate sperm parameters, a significant number of factors can affect these measurements. This paper classifies these factors into four categories: (1) sample and slide (e.g. preincubation time, type of specimen and type of chamber slide); (2) microscope (e.g. light source and microscope stage); (3) hardware and software, including the settings of each system; and (4) user-related factors. We review the effects of the different factors in each category on the measurements made and emphasise the need to take measures to standardise evaluations. The take-home message of the present article is that there are several commercial and useful CASA systems, and all are appropriate for routine analysis. Non-commercial systems may also be good choices when the user needs to adapt the device to specific experimental conditions. In both cases (commercial and non-commercial), it is important that standard protocols are put in place for evaluation, as well as methods to validate the system.

Intraocular Gnathostoma spinigerum. Clinicopathologic study of two cases with review of literature.

PubMed

Biswas, J; Gopal, L; Sharma, T; Badrinath, S S

1994-01-01

Live intraocular nematode is a rare occurrence that is mostly reported in Southeast Asian countries. Common nematodes that are seen live in the eye are microfilaria, Gnathostoma, and Angiostrongylus. Approximately 12 cases of intraocular gnathostomiasis have been reported in the literature. Two cases of intraocular gnathostoma, removed by vitrectomy in the first case and by paracentesis in the second case, are reported. Morphologic study of the parasites in wet preparation was performed under dissecting microscope and fixed in Karnovosky's fixative. Light microscopic and scanning electron microscopic studies were also performed. The first patient had anterior uveitis, multiple iris holes, and dense vitreous haze with fibrous proliferation over the optic disc. On resolution of the vitreous haze, a live worm was seen in the vitreous cavity. The second patient had anterior uveitis with secondary glaucoma, multiple iris holes, mild vitritis, and focal subretinal haemorrhage with subretinal tracts. Four days later a live worm was seen in the anterior chamber and removed. Microscopic study of the parasites from both patients revealed typical head bulb with four circumferential rows of hooklets, and fine cuticular spines were seen on the surface of the body. Iris holes, uveitis, and subretinal haemorrhage with subretinal tract can be characteristic features of intraocular gnathostomiasis. Identification of this parasite can be made by typical features, which can be identified on light and scanning electron microscopic study.

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

PubMed

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

2011-08-21

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. This journal is © The Royal Society of Chemistry 2011

Do Uric Acid Deposits in Zooxanthellae Function as Eye-Spots?

PubMed Central

Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

2009-01-01

The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100–150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot. PMID:19609449

Do uric acid deposits in zooxanthellae function as eye-spots?

PubMed

Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

2009-07-17

The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100-150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot.

A setup for combined multiphoton laser scanning microscopic and multi-electrode patch clamp experiments on brain slices

NASA Astrophysics Data System (ADS)

Helm, P. Johannes; Reppen, Trond; Heggelund, Paul

2009-02-01

Multi Photon Laser Scanning Microscopy (MPLSM) appears today as one of the most powerful experimental tools in cellular neurophysiology, notably in studies of the functional dynamics of signal processing in single neurons. Simultaneous recording of fluorescence signals at high spatial and temporal resolution and electric signals by means of multi electrode patch clamp techniques have provided new paths for the systematic investigation of neuronal mechanisms. In particular, this approach has opened for direct studies of dendritic signal processing in neurons. We report about a setup optimized for simultaneous electrophysiological multi electrode patch clamp and multi photon laser scanning fluorescence microscopic experiments on brain slices. The microscopic system is based on a modified commercially available confocal scanning laser microscope (CLSM). From a technical and operational point of view, two developments are important: Firstly, in order to reduce the workload for the experimentalist, who in general is forced to concentrate on controlling the electrophysiological parameters during the recordings, a system of shutters has been installed together with dedicated electronic modules protecting the photo detectors against destructive light levels caused by erroneous opening or closing of microscopic light paths by the experimentalist. Secondly, the standard detection unit has been improved by installing the photomultiplier tubes (PMT) in a Peltier cooled thermal box shielding the detector from both room temperature and distortions caused by external electromagnetic fields. The electrophysiological system is based on an industrial standard multi patch clamp unit ergonomically arranged around the microscope stage. The electrophysiological and scanning processes can be time coordinated by standard trigger electronics.

A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions.

PubMed

Marquardt, Christian; Paulheim, Alexander; Rohbohm, Nils; Merkel, Rudolf; Sokolowski, Moritz

2017-08-01

We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.

Integrative advances for OCT-guided ophthalmic surgery and intraoperative OCT: microscope integration, surgical instrumentation, and heads-up display surgeon feedback.

PubMed

Ehlers, Justis P; Srivastava, Sunil K; Feiler, Daniel; Noonan, Amanda I; Rollins, Andrew M; Tao, Yuankai K

2014-01-01

To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated.

The morphology of the pineal gland of the yellow-toothed cavy (Galea Spixii Wagler, 1831) and red-rumped agouti (Dasyprocta leporina linnaeus, 1758).

PubMed

Câmara, Felipe Venceslau; Lopes, Igor Renno Guimarães; de Oliveira, Gleidson Benevides; Bezerra, Ferdinando Vinicius Fernandes; de Oliveira, Radan Elvis Matias; Oliveira Júnior, Carlos Magno; Silva, Alexandre Rodrigues; de Oliveira, Moacir Franco

2015-08-01

The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow-toothed cavy and the red-rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra-callosum and ABC type. © 2015 Wiley Periodicals, Inc.

Driving the photoluminescent and structural properties of X2-Y2SiO5 by varying the dopant Dy3+ concentration towards cool WLED applications

NASA Astrophysics Data System (ADS)

Ramakrishna, G.; Nagabhushana, H.; Hareesh, K.; Sunitha, D. V.

2017-07-01

Dy3+ doped Y2SiO5 nanophosphors were synthesized by solution combustion technique using Calotropis gigantean milk latex and NaCl as fuel and flux respectively. Powder X-ray diffraction (PXRD) confirmed the formation of monoclinic X2-phase Y2SiO5 belonging to the phase group C2/c. Fourier transform infrared spectroscopy (FTIR) shows characteristic metal-oxygen (Y-O) vibration band at 721 cm-1. Transmission electron microscopic (TEM) and Scanning electron microscopic (SEM) morphological feature exhibits non-uniform almost spherical shaped nanosized particles. The photoluminescence (PL) emission peaks, recorded at 388 nm, showed radiative emissions at 483, 575 and 636 nm respectively. Judd-Ofelt (JO) analysis was carried out to estimate the radiative (AR) properties, radiative life time (τR), branching ratio (βR) and stimulated emission crossection (σλp). The CIE and CCT was estimated using McCamy empirical formula. In the beginning, the CIE co-ordinate values were lying in the light blue region. However, with increase in Dy3+ concentration the values shifted towards white region. CCT value was found to be ∼6984 K. Therefore, Y2SiO5:Dy3+ (9 mol%) can be used for cool day light and WLED applications.

Interactive effects of melatonin, exercise and diabetes on liver glycogen levels.

PubMed

Bicer, Mursel; Akil, Mustafa; Avunduk, Mustafa Cihat; Kilic, Mehmet; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

2011-01-01

This study aimed to examine the effects of melatonin supplementation on liver glycogen levels in rats with streptozotocin- induced diabetes and subjected to acute swimming exercise. Eighty Sprague-Dawley type adult male rats were divided into eight groups: Group 1, general control; Group 2, melatonin-supplemented control; Group 3, melatonin-supplemented diabetes; Group 4, swimming control; Group 5, melatonin-supplemented swimming; Group 6, melatonin-supplemented diabetic swimming; Group 7, diabetic swimming; Group 8, diabetic control. Melatonin was supplemented at a dose of 3 mg/kg/day intraperitoneally for four weeks. Liver tissue samples were collected and evaluated using a Nikon Eclipse E400 light microscope. All images obtained from the light microscope were transferred to PC medium and evaluated using Clemex PE 3.5 image analysis software. The lowest liver glycogen levels in the study were found in group 4. Liver glycogen levels in groups 3, 6, 7 and 8 (the diabetic groups) were higher than group 4, but lower than those in groups 1 and 2. The lowest liver glycogen levels were obtained in groups 1 and 2. The study indicates that melatonin supplementation maintains the liver glycogen levels that decrease in acute swimming exercise, while induced diabetes prevents this maintenance effect in rats.

Bending the Rules: Widefield Microscopy and the Abbe Limit of Resolution

PubMed Central

Verdaasdonk, Jolien S.; Stephens, Andrew D.; Haase, Julian; Bloom, Kerry

2014-01-01

One of the most fundamental concepts of microscopy is that of resolution–the ability to clearly distinguish two objects as separate. Recent advances such as structured illumination microscopy (SIM) and point localization techniques including photoactivated localization microscopy (PALM), and stochastic optical reconstruction microscopy (STORM) strive to overcome the inherent limits of resolution of the modern light microscope. These techniques, however, are not always feasible or optimal for live cell imaging. Thus, in this review, we explore three techniques for extracting high resolution data from images acquired on a widefield microscope–deconvolution, model convolution, and Gaussian fitting. Deconvolution is a powerful tool for restoring a blurred image using knowledge of the point spread function (PSF) describing the blurring of light by the microscope, although care must be taken to ensure accuracy of subsequent quantitative analysis. The process of model convolution also requires knowledge of the PSF to blur a simulated image which can then be compared to the experimentally acquired data to reach conclusions regarding its geometry and fluorophore distribution. Gaussian fitting is the basis for point localization microscopy, and can also be applied to tracking spot motion over time or measuring spot shape and size. All together, these three methods serve as powerful tools for high-resolution imaging using widefield microscopy. PMID:23893718

Optical spectroscopies diagnose cancer

NASA Astrophysics Data System (ADS)

Alfano, Robert R.; Das, Bidyut B.; Glassman, Wenling S.; Pradhan, Asima; Tang, Gui C.

1992-02-01

Today's medical professional is looking beyond the conventional procedures of X-rays, nuclear radiation, magnetic resonance, chemical analysis, and ultrasound to diagnose diseases ranging from cancer to heart ailments. In view of the possible dangerous side effects of X-rays and nuclear radiation, a need exists for novel techniques in disease detection that can either eliminate or reduce their use in examinations. For more than half a century, fluorescence, absorption, and light scattering spectroscopies have been widely used as probes to acquire fundamental knowledge about various physical, chemical, and biological processes. Light may offer alternatives to X-rays and nuclear approaches, and in some cases is non-invasive. Optical spectroscopy and laser technology may offer techniques for the detection and characterization of physical and chemical changes that occur in diseased tissue on a microscopic level.

Electron Microscopic Analysis of Hippocampal Axo‐Somatic Synapses in a Chronic Stress Model for Depression

PubMed Central

Csabai, Dávid; Seress, László; Varga, Zsófia; Ábrahám, Hajnalka; Miseta, Attila; Wiborg, Ove

2016-01-01

ABSTRACT Stress can alter the number and morphology of excitatory synapses in the hippocampus, but nothing is known about the effect of stress on inhibitory synapses. Here, we used an animal model for depression, the chronic mild stress model, and quantified the number of perisomatic inhibitory neurons and their synapses. We found reduced density of parvalbumin‐positive (PV+) neurons in response to stress, while the density of cholecystokinin‐immunoreactive (CCK+) neurons was unaffected. We did a detailed electron microscopic analysis to quantify the frequency and morphology of perisomatic inhibitory synapses in the hippocampal CA1 area. We analyzed 1100 CA1 pyramidal neurons and 4800 perisomatic terminals in five control and four chronically stressed rats. In the control animals we observed the following parameters: Number of terminals/soma = 57; Number of terminals/100 µm cell perimeter = 10; Synapse/terminal ratio = 32%; Synapse number/100 terminal = 120; Average terminal length = 920nm. None of these parameters were affected by the stress exposure. Overall, these data indicate that despite the depressive‐like behavior and the decrease in the number of perisomatic PV+ neurons in the light microscopic preparations, the number of perisomatic inhibitory synapses on CA1 pyramidal cells was not affected by stress. In the electron microscope, PV+ neurons and the axon terminals appeared to be normal and we did not find any apoptotic or necrotic cells. This data is in sharp contrast to the remarkable remodeling of the excitatory synapses on spines that has been reported in response to stress and depressive‐like behavior. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:27571571

Mobile Technology for the Practice of Pathology.

PubMed

Hartman, Douglas J

2016-03-01

Recently, several technological advances have been introduced to mobile phones leading some people to refer to them as "smartphones." These changes have led to widespread consumer adoption. A similar adoption has occurred within the medical field and this revolution is changing the practice of medicine, including pathology. Several mobile applications have been published for dermatology, orthopedics, ophthalmology, neurosurgery, and clinical pathology. The applications are wide ranging, including mobile technology to increase patient engagement, self-monitoring by patients, clinical algorithm calculation, facilitation between experts to resource-poor environments. These advances have been received with mixed reviews. For anatomic pathology, mobile technology applications can be broken into 4 broad categories: (a) educational uses, (b) microscope with mobile phone, (c) mobile phone as microscope/acquisition device, and (d) miscellaneous. Using a mobile phone as an acquisition device paired with a microscope seems to be the most interesting current application because of the need for expert consultation with resource-poor environments. However, several emerging uses for mobile technology may become more prominent as the technology matures including image analysis, alternative light sources, and increased opportunities for clinician and patient engagement. The flexibility represented by mobile technology represents a burgeoning field in pathology informatics.

From atoms to steps: The microscopic origins of crystal evolution

NASA Astrophysics Data System (ADS)

Patrone, Paul N.; Einstein, T. L.; Margetis, Dionisios

2014-07-01

The Burton-Cabrera-Frank (BCF) theory of crystal growth has been successful in describing a wide range of phenomena in surface physics. Typical crystal surfaces are slightly misoriented with respect to a facet plane; thus, the BCF theory views such systems as composed of staircase-like structures of steps separating terraces. Adsorbed atoms (adatoms), which are represented by a continuous density, diffuse on terraces, and steps move by absorbing or emitting these adatoms. Here we shed light on the microscopic origins of the BCF theory by deriving a simple, one-dimensional (1D) version of the theory from an atomistic, kinetic restricted solid-on-solid (KRSOS) model without external material deposition. We define the time-dependent adatom density and step position as appropriate ensemble averages in the KRSOS model, thereby exposing the non-equilibrium statistical mechanics origins of the BCF theory. Our analysis reveals that the BCF theory is valid in a low adatom-density regime, much in the same way that an ideal gas approximation applies to dilute gasses. We find conditions under which the surface remains in a low-density regime and discuss the microscopic origin of corrections to the BCF model.

Morphological studies of the vestibular nerve

NASA Technical Reports Server (NTRS)

Bergstroem, B.

1973-01-01

The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

Transmission Electron Microscopy Analysis of Skin Lesions from Sporotrichosis Epidemic in Rio de Janeiro, Brazil

PubMed Central

Porto Ferreira, Cassio; Oliveira de Almeida, Ana Cristina; Corte-Real, Suzana

2015-01-01

Transmission electron microscopy can yield useful information in a range of scientific fields; it is capable of imaging at a significantly higher resolution than light microscopes and has been a very useful tool in the identification of morphological changes of the dermis as well as assessment of changes in the extracellular matrix. Our aim is to characterize by electron microscopy the cellular profile of lesions caused by Sporothrix schenckii from the sporotrichosis epidemic in its zoonotic form that occurs in Rio de Janeiro, Brazil. PMID:25653392

Fiber optic biofluorometer for physiological research on muscle slices

NASA Astrophysics Data System (ADS)

Belz, Mathias; Dendorfer, Andreas; Werner, Jan; Lambertz, Daniel; Klein, Karl-Friedrich

2016-03-01

A focus of research in cell physiology is the detection of Ca2+, NADH, FAD, ATPase activity or membrane potential, only to name a few, in muscle tissues. In this work, we report on a biofluorometer using ultraviolet light emitting diodes (UV-LEDs), optical fibers and two photomultipliers (PMTs) using synchronized fluorescence detection with integrated background correction to detect free calcium, Ca2+, in cardiac muscle tissue placed in a horizontal tissue bath and a microscope setup. Fiber optic probes with imaging optics have been designed to transport excitation light from the biofluorometer's light output to a horizontal tissue bath and to collect emission light from a tissue sample of interest to two PMTs allowing either single excitation / single emission or ratiometric, dual excitation / single emission or single excitation / dual emission fluorescence detection of indicator dyes or natural fluorophores. The efficient transport of light from the excitation LEDs to the tissue sample, bleaching effects of the excitation light in both, polymer and fused silica-based fibers will be discussed. Furthermore, a new approach to maximize light collection of the emission light using high NA fibers and high NA coupling optics will be shown. Finally, first results on Ca2+ measurements in cardiac muscle slices in a traditional microscope setup and a horizontal tissue bath using fiber optic probes will be introduced and discussed.

Generation of multiple Bessel beams for a biophotonics workstation.

PubMed

Cizmár, T; Kollárová, V; Tsampoula, X; Gunn-Moore, F; Sibbett, W; Bouchal, Z; Dholakia, K

2008-09-01

We present a simple method using an axicon and spatial light modulator to create multiple parallel Bessel beams and precisely control their individual positions in three dimensions. This technique is tested as an alternative to classical holographic beam shaping commonly used now in optical tweezers. Various applications of precise control of multiple Bessel beams are demonstrated within a single microscope giving rise to new methods for three-dimensional positional control of trapped particles or active sorting of micro-objects as well as "focus-free" photoporation of living cells. Overall this concept is termed a 'biophotonics workstation' where users may readily trap, sort and porate material using Bessel light modes in a microscope.

Light and Life in Baltimore—and Beyond

PubMed Central

Edidin, Michael

2015-01-01

Baltimore has been the home of numerous biophysical studies using light to probe cells. One such study, quantitative measurement of lateral diffusion of rhodopsin, set the standard for experiments in which recovery after photobleaching is used to measure lateral diffusion. Development of this method from specialized microscopes to commercial scanning confocal microscopes has led to widespread use of the technique to measure lateral diffusion of membrane proteins and lipids, and as well diffusion and binding interactions in cell organelles and cytoplasm. Perturbation of equilibrium distributions by photobleaching has also been developed into a robust method to image molecular proximity in terms of fluorescence resonance energy transfer between donor and acceptor fluorophores. PMID:25650914

A stress-controlled shear cell for small-angle light scattering and microscopy.

PubMed

Aime, S; Ramos, L; Fromental, J M; Prévot, G; Jelinek, R; Cipelletti, L

2016-12-01

We develop and test a stress-controlled, parallel plates shear cell that can be coupled to an optical microscope or a small angle light scattering setup, for simultaneous investigation of the rheological response and the microscopic structure of soft materials under an imposed shear stress. In order to minimize friction, the cell is based on an air bearing linear stage, the stress is applied through a contactless magnetic actuator, and the strain is measured through optical sensors. We discuss the contributions of inertia and of the small residual friction to the measured signal and demonstrate the performance of our device in both oscillating and step stress experiments on a variety of viscoelastic materials.

Corrugated metal-coated tapered tip for scanning near-field optical microscope.

PubMed

Antosiewicz, Tomasz J; Szoplik, Tomasz

2007-08-20

This paper addresses an important issue of light throughput of a metal-coated tapered tip for scanning near-field microscope (SNOM). Corrugations of the interface between the fiber core and metal coating in the form of parallel grooves of different profiles etched in the core considerably increase the energy throughput. In 2D FDTD simulations in the Cartesian coordinates we calculate near-field light emitted from such tips. For a certain wavelength range total intensity of forward emission from the corrugated tip is 10 times stronger than that from a classical tapered tip. When realized in practice the idea of corrugated tip may lead up to twice better resolution of SNOM.

Enhancing extracellular electron transfer between Pseudomonas aeruginosa PAO1 and light driven semiconducting birnessite.

PubMed

Ren, Guiping; Sun, Yuan; Ding, Yang; Lu, Anhuai; Li, Yan; Wang, Changqiu; Ding, Hongrui

2018-06-02

In recent years, considerable research effort has explored the interaction between semiconducting minerals and microorganisms, such relationship is a promising way to increase the efficiency of bioelectrochemical systems. Herein, the enhancement of electron transfer between birnessite photoanodes and Pseudomonas aeruginosa PAO1 under visible light was investigated. Under light illumination and positive bias, the light-birnessite-PAO1 electrochemical system generated a photocurrent of 279.57 μA/cm 2 , which is 322% and 170% higher than those in the abiotic control and dead culture, suggesting photoenhanced electrochemical interaction between birnessite and Pseudomonas. The I-t curves presented repeatable responses to light on/off cycles, and multi-conditions analyses indicated that the enhanced photocurrent was attributed to the additional redox species associated with P. aeruginosa PAO1 and with the biofilm on birnessite. Electroconductibility analysis was conducted on the biofilm cellularly by conductive atomic force microscope. Pyocyanin was isolated as the biosynthesized extracellular shuttle and characterized by cyclic voltammetry and surface-enhanced Raman spectroscopy. Rapid bioelectron transfer driven by light was observed. The results suggest new opportunities for designing photo-bioelectronic devices and expanding our understanding of extracellular electron transfer with semiconducting minerals under light in nature environments. Copyright © 2018. Published by Elsevier B.V.

Membranous nephropathy (bubbling appearance and spike formation) without immunoglobulin deposition in a patient with systemic lupus erythematosus.

PubMed

Miura, Naoto; Mori, Yuki; Yoshino, Masabumi; Suga, Norihiro; Kitagawa, Wataru; Yamada, Harutaka; Nishikawa, Kazuhiro; Imai, Hirokazu

2008-12-01

A 53-year-old Japanese man with systemic lupus erythematosus developed proteinuria and hematuria after a urinary stone episode. A light microscopic study of a kidney biopsy specimen demonstrated a bubbling appearance and spike formation of the basement membrane. Immunofluorescent studies revealed that there were no significant depositions of immunoglobulins, such as IgG (-), IgA (-), IgM (+/-), kappa light chain (+/-), lambda light chain (+/-), or C3 (-) in the glomerular capillary wall, though C1q was present as one-plus positive staining in mesangial areas. Electron microscopic studies showed that the thickness of the basement membrane varied from thin to thick without electron dense deposits, and that the cellular components of the podocyte were irregularly present in the basement membrane. Urinary protein decreased after the usage of prednisolone and mizoribine; however, proteinuria aggravated after an episode of urinary stone during the same treatment.

Development of UV-curable liquid for in-liquid fluorescence alignment in ultraviolet nanoimprint lithography

NASA Astrophysics Data System (ADS)

Ochiai, Kento; Kikuchi, Eri; Ishito, Yota; Kumagai, Mari; Nakamura, Takahiro; Nakagawa, Masaru

2018-06-01

We studied a fluorescent UV-curable resin suitable for fluorescence alignment in UV nanoimprinting. The addition of a cationic fluorescent dye caused radical photopolymerization of a UV-curable resin by exposure to visible excitation light for fluorescence microscope observation. The microscope observation of a resin film prepared by pressing resin droplets on a silica substrate with a fluorinated silica superstrate revealed that the cationic dye molecules were preferably adsorbed onto the silica surface. It was indicated that the dye molecules concentrated on the silica surface may cause the photocuring. A nonionic fluorescent dye was selected owing to its low polar symmetrical structure and its solubility parameter close to monomers. The fluorescent UV-curable resin with the nonionic dye showed uncured stability to exposure to visible excitation light for 30 min with a light intensity of 8.5 mW cm‑2 detected at 530 nm.

Maintenance on the Advanced Colloids Experiment Module

NASA Image and Video Library

2018-04-16

iss055e035366 (April 16, 2018) --- NASA astronaut Ricky Arnold performs maintenance on the Advanced Colloids Experiment Module located inside the Light Microscopy Module which is a modified commercial, highly flexible, state-of-the-art light imaging microscope facility that provides researchers with powerful diagnostic hardware and software in microgravity.

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

NASA Astrophysics Data System (ADS)

Masters, Barry R.

1990-11-01

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

Self-referenced axial chromatic dispersion measurement in multiphoton microscopy through 2-color THG imaging.

PubMed

Du, Yu; Zhuang, Ziwei; He, Jiexing; Liu, Hongji; Qiu, Ping; Wang, Ke

2018-05-16

With tunable excitation light, multiphoton microscopy (MPM) is widely used for imaging biological structures at subcellular resolution. Axial chromatic dispersion, present in virtually every transmissive optical system including the multiphoton microscope, leads to focal (and the resultant image) plane separation. Here we demonstrate experimentally a technique to measure the axial chromatic dispersion in a multiphoton microscope, using simultaneous 2-color third-harmonic generation (THG) imaging excited by a 2-color soliton source with tunable wavelength separation. Our technique is self-referenced, eliminating potential measurement error when 1-color tunable excitation light is used which necessitates reciprocating motion of the mechanical translation stage. Using this technique, we demonstrate measured axial chromatic dispersion with 2 different objective lenses in a multiphoton microscope. Further measurement in a biological sample also indicates that this axial chromatic dispersion, in combination with 2-color imaging, may open up opportunity for simultaneous imaging of two different axial planes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Eyecup scope—optical recordings of light stimulus-evoked fluorescence signals in the retina

PubMed Central

Hausselt, Susanne E.; Breuninger, Tobias; Castell, Xavier; Denk, Winfried; Margolis, David J.; Detwiler, Peter B.

2009-01-01

Dendritic signals play an essential role in processing visual information in the retina. To study them in neurites too small for electrical recording, we developed an instrument that combines a multi-photon (MP) microscope with a through-the-objective high-resolution visual stimulator. An upright microscope was designed that uses the objective lens for both MP imaging and delivery of visual stimuli to functionally intact retinal explants or eyecup preparations. The stimulator consists of a miniature liquid-crystal-on-silicon display coupled into the optical path of an infrared-excitation laser-scanning microscope. A pair of custom-made dichroic filters allows light from the excitation laser and three spectral bands (‘colors’) from the stimulator to reach the retina, leaving two intermediate bands for fluorescence imaging. Special optics allow displacement of the stimulator focus relative to the imaging focus. Spatially resolved changes in calcium-indicator fluorescence in response to visual stimuli were recorded in dendrites of different types of mammalian retinal neurons. PMID:19023590

Adaptation of commercial microscopes for advanced imaging applications

NASA Astrophysics Data System (ADS)

Brideau, Craig; Poon, Kelvin; Stys, Peter

2015-03-01

Today's commercially available microscopes offer a wide array of options to accommodate common imaging experiments. Occasionally, an experimental goal will require an unusual light source, filter, or even irregular sample that is not compatible with existing equipment. In these situations the ability to modify an existing microscopy platform with custom accessories can greatly extend its utility and allow for experiments not possible with stock equipment. Light source conditioning/manipulation such as polarization, beam diameter or even custom source filtering can easily be added with bulk components. Custom and after-market detectors can be added to external ports using optical construction hardware and adapters. This paper will present various examples of modifications carried out on commercial microscopes to address both atypical imaging modalities and research needs. Violet and near-ultraviolet source adaptation, custom detection filtering, and laser beam conditioning and control modifications will be demonstrated. The availability of basic `building block' parts will be discussed with respect to user safety, construction strategies, and ease of use.

Space-resolved diffusing wave spectroscopy measurements of the macroscopic deformation and the microscopic dynamics in tensile strain tests

NASA Astrophysics Data System (ADS)

Nagazi, Med-Yassine; Brambilla, Giovanni; Meunier, Gérard; Marguerès, Philippe; Périé, Jean-Noël; Cipelletti, Luca

2017-01-01

We couple a laser-based, space-resolved dynamic light scattering apparatus to a universal traction machine for mechanical extensional tests. We perform simultaneous optical and mechanical measurements on polyether ether ketone, a semi-crystalline polymer widely used in the industry. Due to the high turbidity of the sample, light is multiply scattered by the sample and the diffusing wave spectroscopy (DWS) formalism is used to interpret the data. Space-resolved DWS yields spatial maps of the sample strain and of the microscopic dynamics. An excellent agreement is found between the strain maps thus obtained and those measured by a conventional stereo-digital image correlation technique. The microscopic dynamics reveals both affine motion and plastic rearrangements. Thanks to the extreme sensitivity of DWS to displacements as small as 1 nm, plastic activity and its spatial localization can be detected at an early stage of the sample strain, making the technique presented here a valuable complement to existing material characterization methods.

COMPACT NON-CONTACT TOTAL EMISSION DETECTION FOR IN-VIVO MULTI-PHOTON EXCITATION MICROSCOPY

PubMed Central

Glancy, Brian; Karamzadeh, Nader S.; Gandjbakhche, Amir H.; Redford, Glen; Kilborn, Karl; Knutson, Jay R.; Balaban, Robert S.

2014-01-01

Summary We describe a compact, non-contact design for a Total Emission Detection (c-TED) system for intra-vital multi-photon imaging. To conform to a standard upright two-photon microscope design, this system uses a parabolic mirror surrounding a standard microscope objective in concert with an optical path that does not interfere with normal microscope operation. The non-contact design of this device allows for maximal light collection without disrupting the physiology of the specimen being examined. Tests were conducted on exposed tissues in live animals to examine the emission collection enhancement of the c-TED device compared to heavily optimized objective-based emission collection. The best light collection enhancement was seen from murine fat (5×-2× gains as a function of depth), while murine skeletal muscle and rat kidney showed gains of over two and just under two-fold near the surface, respectively. Gains decreased with imaging depth (particularly in the kidney). Zebrafish imaging on a reflective substrate showed close to a two-fold gain throughout the entire volume of an intact embryo (approximately 150 μm deep). Direct measurement of bleaching rates confirmed that the lower laser powers (enabled by greater light collection efficiency) yielded reduced photobleaching in vivo. The potential benefits of increased light collection in terms of speed of imaging and reduced photo-damage, as well as the applicability of this device to other multi-photon imaging methods is discussed. PMID:24251437

Modular low-light microscope for imaging cellular bioluminescence and radioluminescence

PubMed Central

Kim, Tae Jin; Türkcan, Silvan; Pratx, Guillem

2017-01-01

Low-light microscopy methods are receiving increased attention as new applications have emerged. One such application is to allow longitudinal imaging of light-sensitive cells with no phototoxicity and no photobleaching of fluorescent biomarkers. Another application is for imaging signals that are inherently dim and undetectable using standard microscopy, such as bioluminescence, chemiluminescence, or radioluminescence. In this protocol, we provide instructions on how to build a modular low-light microscope (1-4 d) by coupling two microscope objective lenses, back-to-back from each other, using standard optomechanical components. We also provide directions on how to image dim signals such as radioluminescence (1-1.5 h), bioluminescence (∼30 min) and low-excitation fluorescence (∼15 min). In particular, radioluminescence microscopy is explained in detail as it is a newly developed technique, which enables the study of small molecule transport (eg. radiolabeled drugs, metabolic precursors, and nuclear medicine contrast agents) by single cells without perturbing endogenous biochemical processes. In this imaging technique, a scintillator crystal (eg. CdWO4) is placed in close proximity to the radiolabeled cells, where it converts the radioactive decays into optical flashes detectable using a sensitive camera. Using the image reconstruction toolkit provided in this protocol, the flashes can be reconstructed to yield high-resolution image of the radiotracer distribution. With appropriate timing, the three aforementioned imaging modalities may be performed altogether on a population of live cells, allowing the user to perform parallel functional studies of cell heterogeneity at the single-cell level. PMID:28426025

A Comparative Study Between Smartphone-Based Microscopy and Conventional Light Microscopy in 1021 Dermatopathology Specimens.

PubMed

Jahan-Tigh, Richard R; Chinn, Garrett M; Rapini, Ronald P

2016-01-01

The incorporation of high-resolution cameras into smartphones has allowed for a variety of medical applications including the use of lens attachments that provide telescopic, macroscopic, and dermatoscopic data, but the feasibility and performance characteristics of such a platform for use in dermatopathology have not been described. To determine the diagnostic performance of a smartphone microscope compared to traditional light microscopy in dermatopathology specimens. A simple smartphone microscope constructed with a 3-mm ball lens was used to prospectively evaluate 1021 consecutive dermatopathology cases in a blinded fashion. Referred, consecutive specimens from the community were evaluated at a single university hospital. The performance characteristics of the smartphone platform were calculated by using conventional light microscopy as the gold standard. The sensitivity and specificity for the diagnosis of melanoma, nonmelanoma skin cancers, and other miscellaneous conditions by the phone microscopy platform, as compared with traditional light microscopy, were calculated. For basal cell carcinoma (n = 136), the sensitivity and specificity of smartphone microscopy were 95.6% and 98.1%, respectively. The sensitivity and specificity for squamous cell carcinoma (n = 94) were 89.4% and 97.3%, respectively. The lowest sensitivity was found in melanoma (n = 15) at 60%, although the specificity was high at 99.1%. The accuracy of diagnosis of inflammatory conditions and other neoplasms was variable. Mobile phone-based microscopy has excellent performance characteristics for the inexpensive diagnosis of nonmelanoma skin cancers in a setting where a traditional microscope is not available.

Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms.

PubMed

Steinbach, Gábor; Kaňa, Radek

2016-04-01

Photosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (through Time Controller offered by Olympus or Experiment Designer offered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with the Cell⊕Finder software was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) the Cell⊕Finder software with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser. Cell⊕Finder can be downloaded from http://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity in Synechocystis sp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

Comparison of two methods of visual magnification for removal of adhesive flash during bracket placement using two types of orthodontic bonding agents

PubMed Central

Alencar, Estefania Queiroga de Santana e; Nobrega, Maria de Lourdes Martins; Dametto, Fabio Roberto; dos Santos, Patrícia Bittencourt Dutra; Pinheiro, Fabio Henrique de Sá Leitão

2016-01-01

ABSTRACT Objective: This study aimed to evaluate the effectiveness of two methods of visual magnification (operating microscope and light head magnifying glass) for removal of composite flash around orthodontic metal brackets. Material and Methods: Brackets were bonded in the center of the clinical crown of sixty well-preserved human premolars. Half of the sample was bonded with conventional Transbond XT (3M Unitek TM, USA), whereas the other half was bonded with Transbond TM Plus Color Change (3M Unitek TM, USA). For each type of composite, the choice of method to remove the flash was determined by randomly distributing the teeth into the following subgroups: A (removal by naked eye, n = 10), B (removal with the aid of light head magnifying glass, under 4x magnification, n = 10), and C (removal with the aid of an operating microscope, under 40x magnification, n = 10). Brackets were debonded and teeth taken to a scanning electron microscope (SS-x-550, Shimadzu, Japan) for visualization of their buccal surface. Quantification of composite flash was performed with Image Pro Plus software, and values were compared by Kruskal-Wallis test and Dunn’s post-hoc test at 5% significance level. Results: Removal of pigmented orthodontic adhesive with the aid of light head magnifying glass proved, in general, to be advantageous in comparison to all other methods. Conclusion: There was no advantage in using Transbond TM Plus Color Change alone. Further studies are necessary to draw a more definitive conclusion in regards to the benefits of using an operating microscope. PMID:28125139

Development of SEM/STEM-WDX for highly sensitive detection of light elements

NASA Astrophysics Data System (ADS)

Anan, Y.; Koguchi, M.; Kimura, T.; Sekiguchi, T.

2018-02-01

In this study, to detect the light element lithium (Li) and to detect low dosed Boron (B) in the local area at nm order, we developed an analytical electron microscope equipped with an improved serial (S)-type WDX (wavelength dispersive X-ray spectroscopy) system. In detail, to detect Li, we developed a high-conductivity multi-capillary X-ray (MCX) lens, and a diffractor with a lattice spacing (d) of 15 nm, and with a spacing variation (δ d) of 0.8 nm. Moreover, to detect low dosed light element B, we designed a high-conductivity MCX lens based on the soft X-ray reflectivity in the capillary and calculation. We developed a large-solid-angle MCX lens whose conductivity of the characteristic X-rays of B became 20 times higher than that of an MCX lens with a 30-mm focal length. Our developed analytical electron microscope was applied to a LiAl specimen and a low B-doped Si substrate specimen, and the performance of this analytical electron microscope was evaluated. As a results, this analytical electron microscope could detect the characteristic X-rays of Li with a minimum mass fraction (MMF) of 8.4 atomic % (at. %). The energy resolution was 1 eV at 55 eV. From the results of measuring the line profile of B for the unpatterned B-implantation area on a B-doped Si substrate specimen, the measured line profile data were in good agreement with secondary ion mass spectrometry data up to a depth of 100 nm with a B concentration of 0.05 at. %.

Non-invasive intraoperative optical coherence tomography of the resection cavity during surgery of intrinsic brain tumors

NASA Astrophysics Data System (ADS)

Giese, A.; Böhringer, H. J.; Leppert, J.; Kantelhardt, S. R.; Lankenau, E.; Koch, P.; Birngruber, R.; Hüttmann, G.

2006-02-01

Optical coherence tomography (OCT) is a non-invasive imaging technique with a micrometer resolution. It allows non-contact / non-invasive analysis of central nervous system tissues with a penetration depth of 1-3,5 mm reaching a spatial resolution of approximately 4-15 μm. We have adapted spectral-domain OCT (SD-OCT) and time-domain OCT (TD-OCT) for intraoperative detection of residual tumor during brain tumor surgery. Human brain tumor tissue and areas of the resection cavity were analyzed during the resection of gliomas using this new technology. The site of analysis was registered using a neuronavigation system and biopsies were taken and submitted to routine histology. We have used post image acquisition processing to compensate for movements of the brain and to realign A-scan images for calculation of a light attenuation factor. OCT imaging of normal cortex and white matter showed a typical light attenuation profile. Tumor tissue depending on the cellularity of the specimen showed a loss of the normal light attenuation profile resulting in altered light attenuation coefficients compared to normal brain. Based on this parameter and the microstructure of the tumor tissue, which was entirely absent in normal tissue, OCT analysis allowed the discrimination of normal brain tissue, invaded brain, solid tumor tissue, and necrosis. Following macroscopically complete resections OCT analysis of the resection cavity displayed the typical microstructure and light attenuation profile of tumor tissue in some specimens, which in routine histology contained microscopic residual tumor tissue. We have demonstrated that this technology may be applied to the intraoperative detection of residual tumor during resection of human gliomas.

Improvements in low-cost label-free QPI microscope for live cell imaging

NASA Astrophysics Data System (ADS)

Seniya, C.; Towers, C. E.; Towers, D. P.

2017-07-01

This paper reports an improvement in the development of a low-cost QPI microscope offering new capabilities in term of phase measurement accuracy for label-free live samples in the longer term (i.e., hours to days). The spatially separated scattered and non-scattered image light fields are reshaped in the Fourier plane and modulated to form an interference image at a CCD camera. The apertures that enable these two beams to be generated have been optimised by means of laser-cut apertures placed on the mirrors of a Michelson interferometer and has improved the phase measuring and reconstruction capability of the QPI microscope. The microscope was tested with transparent onion cells as an object of interest.

Comprehensive study of unexpected microscope condensers formed in sample arrangements commonly used in optical microscopy.

PubMed

Desai, Darshan B; Aldawsari, Mabkhoot Mudith S; Alharbi, Bandar Mohammed H; Sen, Sanchari; Grave de Peralta, Luis

2015-09-01

We show that various setups for optical microscopy which are commonly used in biomedical laboratories behave like efficient microscope condensers that are responsible for observed subwavelength resolution. We present a series of experiments and simulations that reveal how inclined illumination from such unexpected condensers occurs when the sample is perpendicularly illuminated by a microscope's built-in white-light source. In addition, we demonstrate an inexpensive add-on optical module that serves as an efficient and lightweight microscope condenser. Using such add-on optical module in combination with a low-numerical-aperture objective lens and Fourier plane imaging microscopy technique, we demonstrate detection of photonic crystals with a period nearly eight times smaller than the Rayleigh resolution limit.

Optical path difference microscopy with a Shack-Hartmann wavefront sensor.

PubMed

Gong, Hai; Agbana, Temitope E; Pozzi, Paolo; Soloviev, Oleg; Verhaegen, Michel; Vdovin, Gleb

2017-06-01

In this Letter, we show that a Shack-Hartmann wavefront sensor can be used for the quantitative measurement of the specimen optical path difference (OPD) in an ordinary incoherent optical microscope, if the spatial coherence of the illumination light in the plane of the specimen is larger than the microscope resolution. To satisfy this condition, the illumination numerical aperture should be smaller than the numerical aperture of the imaging lens. This principle has been successfully applied to build a high-resolution reference-free instrument for the characterization of the OPD of micro-optical components and microscopic biological samples.

Wide-field synovial fluid imaging using polarized lens-free on-chip microscopy for point-of-care diagnostics of gout (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhang, Yibo; Lee, Seung Yoon; Zhang, Yun; Furst, Daniel; Fitzgerald, John; Ozcan, Aydogan

2016-03-01

Gout and pseudogout are forms of crystal arthropathy caused by monosodium urate (MSU) and calcium pyrophosphate dehydrate (CPPD) crystals in the joint, respectively, that can result in painful joints. Detecting the unique-shaped, birefringent MSU/CPPD crystals in a synovial fluid sample using a compensated polarizing microscope has been the gold-standard for diagnosis since the 1960's. However, this can be time-consuming and inaccurate, especially if there are only few crystals in the fluid. The high-cost and bulkiness of conventional microscopes can also be limiting for point-of-care diagnosis. Lens-free on-chip microscopy based on digital holography routinely achieves high-throughput and high-resolution imaging in a cost-effective and field-portable design. Here we demonstrate, for the first time, polarized lens-free on-chip imaging of MSU and CPPD crystals over a wide field-of-view (FOV ~ 20.5 mm2, i.e., <20-fold larger compared a typical 20X objective-lens FOV) for point-of-care diagnostics of gout and pseudogout. Circularly polarizer partially-coherent light is used to illuminate the synovial fluid sample on a glass slide, after which a quarter-wave-plate and an angle-mismatched linear polarizer are used to analyze the transmitted light. Two lens-free holograms of the MSU/CPPD sample are taken, with the sample rotated by 90°, to rule out any non-birefringent objects within the specimen. A phase-recovery algorithm is also used to improve the reconstruction quality, and digital pseudo-coloring is utilized to match the color and contrast of the lens-free image to that of a gold-standard microscope image to ease the examination by a rheumatologist or a laboratory technician, and to facilitate computerized analysis.

Dry Eye Following Phacoemulsification Surgery and its Relation to Associated Intraoperative Risk Factors.

PubMed

Sahu, P K; Das, G K; Malik, Aman; Biakthangi, Laura

2015-01-01

The purpose was to study dry eye following phacoemulsification surgery and analyze its relation to associated intra-operative risk factors. A prospective observational study was carried out on 100 eyes of 100 patients without preoperative dry eye. Schirmer's Test I, tear meniscus height, tear break-up time, and lissamine green staining of cornea and conjunctiva were performed preoperatively and at 5 days, 10 days, 1-month, and 2 months after phacoemulsification surgery, along with the assessment of subjective symptoms, using the dry eye questionnaire. The correlations between these values and the operating microscope light exposure time along with the cumulative dissipated energy (CDE) were investigated. There was a significant deterioration of all dry eye test values following phacoemulsification surgery along with an increase in subjective symptoms. These values started improving after 1-month postoperatively, but preoperative levels were not achieved till 2 months after surgery. Correlations of dry eye test values were noted with the operating microscope light exposure time and CDE, but they were not significant. Phacoemulsification surgery is capable of inducing dry eye, and patients should be informed accordingly prior to surgery. The clinician should also be cognizant that increased CDE can induce dry eyes even in eyes that were healthy preoperatively. In addition, intraoperative exposure to the microscopic light should be minimized.

Longitudinal spatial coherence gated high-resolution tomography and quantitative phase microscopy of biological cells and tissues with uniform illumination

NASA Astrophysics Data System (ADS)

Mehta, Dalip Singh; Ahmad, Azeem; Dubey, Vishesh; Singh, Veena; Butola, Ankit; Mohanty, Tonmoy; Nandi, Sreyankar

2018-02-01

We report longitudinal spatial coherence (LSC) gated high-resolution tomography and quantitative phase microscopy of biological cells and tissues with uniform illumination using laser as a light source. To accomplish this a pseudo thermal light source was synthesized by passing laser beams through an optical system, which is basically a speckle reduction system with combined effect of spatial, temporal, angular and polarisation diversity. The longitudinal spatial coherence length of such light was significantly reduced by synthesizing a pseudo thermal source with the combined effect of spatial, angular and temporal diversity. This results in a low spatially coherent (i.e., broad angular frequency spectrum) light source with narrow temporal frequency spectrum. Light from such a pseudo thermal light source was passed through an interference microscope with varying magnification, such as, 10X and 50X. The interference microscope was used for full-field OCT imaging of multilayer objects and topography of industrial objects. Experimental results of optical sectioning of multilayer biological objects with high axial-resolution less than 10μm was achieved which is comparable to broadband white light source. The synthesized light source with reduced speckles having uniform illumination on the sample, which can be very useful for fluorescence microscopy as well as quantitative phase microscopy with less phase noise. The present system does not require any dispersion compensation optical system for biological samples as a highly monochromatic light source is used.

Evaluation of a Mobile Phone-Based Microscope for Screening of Schistosoma haematobium Infection in Rural Ghana.

PubMed

Bogoch, Isaac I; Koydemir, Hatice C; Tseng, Derek; Ephraim, Richard K D; Duah, Evans; Tee, Joseph; Andrews, Jason R; Ozcan, Aydogan

2017-06-01

AbstractSchistosomiasis affects over 170 million people in Africa. Here we compare a novel, low-cost mobile phone microscope to a conventional light microscope for the label-free diagnosis of Schistosoma haematobium infections in a rural Ghanaian school setting. We tested the performance of our handheld microscope using 60 slides that were randomly chosen from an ongoing epidemiologic study in school-aged children. The mobile phone microscope had a sensitivity of 72.1% (95% confidence interval [CI]: 56.1-84.2), specificity of 100% (95% CI: 75.9-100), positive predictive value of 100% (95% CI: 86.3-100), and a negative predictive value of 57.1% (95% CI: 37.4-75.0). With its modest sensitivity and high specificity, this handheld and cost-effective mobile phone-based microscope is a stepping-stone toward developing a powerful tool in clinical and public health settings where there is limited access to conventional laboratory diagnostic support.

Critical dimensional linewidth calibration using UV microscope and laser interferometry

NASA Astrophysics Data System (ADS)

Li, Qi; Gao, Si-tian; Li, Wei; Lu, Ming-zhen; Zhang, Ming-kai

2013-10-01

In order to calibrate the critical dimensional (CD) uncertainty of lithography masks in semiconductor manufacturing, NIM is building a two dimensional metrological UV microscope which has traceable measurement ability for nanometer linewidths and pitches. The microscope mainly consists of UV light receiving components, piezoelectric ceramics (PZT) driven stage and interferometer calibration framework. In UV light receiving components they include all optical elements on optical path. The UV light originates from Köhler high aperture transmit/reflect illumination sources; then goes through objective lens to UV splitting optical elements; after that, one part of light attains UV camera for large range calibration, the other part of light passes through a three dimensional adjusted pinhole and is collected by PMT for nanoscale scanning. In PZT driven stage, PZT stick actuators with closed loop control are equipped to push/pull a flexural hinge based platform. The platform has a novel designed compound flexural hinges which nest separate X, Y direction moving mechanisms within one layer but avoiding from mutual cross talk, besides this, the hinges also contain leverage structures to amplify moving distance. With these designs, the platform can attain 100 μm displacement ranges as well as 1 nm resolution. In interferometer framework a heterodyne multi-pass interferometer is mounted on the platform, which measures X-Y plane movement and Z axis rotation, through reference mirror mounted on objective lens tube and Zerodur mirror mounted on PZT platform, the displacement is traced back to laser wavelength. When development is finished, the apparatus can offer the capability to calibrate one dimensional linewidths and two dimensional pitches ranging from 200nm to 50μm with expanded uncertainty below 20nm.

Assessing various Infrared (IR) microscopic imaging techniques for post-mortem interval evaluation of human skeletal remains.

PubMed

Woess, Claudia; Unterberger, Seraphin Hubert; Roider, Clemens; Ritsch-Marte, Monika; Pemberger, Nadin; Cemper-Kiesslich, Jan; Hatzer-Grubwieser, Petra; Parson, Walther; Pallua, Johannes Dominikus

2017-01-01

Due to the influence of many environmental processes, a precise determination of the post-mortem interval (PMI) of skeletal remains is known to be very complicated. Although methods for the investigation of the PMI exist, there still remains much room for improvement. In this study the applicability of infrared (IR) microscopic imaging techniques such as reflection-, ATR- and Raman- microscopic imaging for the estimation of the PMI of human skeletal remains was tested. PMI specific features were identified and visualized by overlaying IR imaging data with morphological tissue structures obtained using light microscopy to differentiate between forensic and archaeological bone samples. ATR and reflection spectra revealed that a more prominent peak at 1042 cm-1 (an indicator for bone mineralization) was observable in archeological bone material when compared with forensic samples. Moreover, in the case of the archaeological bone material, a reduction in the levels of phospholipids, proteins, nucleic acid sugars, complex carbohydrates as well as amorphous or fully hydrated sugars was detectable at (reciprocal wavelengths/energies) between 3000 cm-1 to 2800 cm-1. Raman spectra illustrated a similar picture with less ν2PO43-at 450 cm-1 and ν4PO43- from 590 cm-1 to 584 cm-1, amide III at 1272 cm-1 and protein CH2 deformation at 1446 cm-1 in archeological bone material/samples/sources. A semi-quantitative determination of various distributions of biomolecules by chemi-maps of reflection- and ATR- methods revealed that there were less carbohydrates and complex carbohydrates as well as amorphous or fully hydrated sugars in archaeological samples compared with forensic bone samples. Raman- microscopic imaging data showed a reduction in B-type carbonate and protein α-helices after a PMI of 3 years. The calculated mineral content ratio and the organic to mineral ratio displayed that the mineral content ratio increases, while the organic to mineral ratio decreases with time. Cluster-analyses of data from Raman microscopic imaging reconstructed histo-anatomical features in comparison to the light microscopic image and finally, by application of principal component analyses (PCA), it was possible to see a clear distinction between forensic and archaeological bone samples. Hence, the spectral characterization of inorganic and organic compounds by the afore mentioned techniques, followed by analyses such as multivariate imaging analysis (MIAs) and principal component analyses (PCA), appear to be suitable for the post mortem interval (PMI) estimation of human skeletal remains.

Assessing various Infrared (IR) microscopic imaging techniques for post-mortem interval evaluation of human skeletal remains

PubMed Central

Roider, Clemens; Ritsch-Marte, Monika; Pemberger, Nadin; Cemper-Kiesslich, Jan; Hatzer-Grubwieser, Petra; Parson, Walther; Pallua, Johannes Dominikus

2017-01-01

Due to the influence of many environmental processes, a precise determination of the post-mortem interval (PMI) of skeletal remains is known to be very complicated. Although methods for the investigation of the PMI exist, there still remains much room for improvement. In this study the applicability of infrared (IR) microscopic imaging techniques such as reflection-, ATR- and Raman- microscopic imaging for the estimation of the PMI of human skeletal remains was tested. PMI specific features were identified and visualized by overlaying IR imaging data with morphological tissue structures obtained using light microscopy to differentiate between forensic and archaeological bone samples. ATR and reflection spectra revealed that a more prominent peak at 1042 cm-1 (an indicator for bone mineralization) was observable in archeological bone material when compared with forensic samples. Moreover, in the case of the archaeological bone material, a reduction in the levels of phospholipids, proteins, nucleic acid sugars, complex carbohydrates as well as amorphous or fully hydrated sugars was detectable at (reciprocal wavelengths/energies) between 3000 cm-1 to 2800 cm-1. Raman spectra illustrated a similar picture with less ν2PO43−at 450 cm-1 and ν4PO43− from 590 cm-1 to 584 cm-1, amide III at 1272 cm-1 and protein CH2 deformation at 1446 cm-1 in archeological bone material/samples/sources. A semi-quantitative determination of various distributions of biomolecules by chemi-maps of reflection- and ATR- methods revealed that there were less carbohydrates and complex carbohydrates as well as amorphous or fully hydrated sugars in archaeological samples compared with forensic bone samples. Raman- microscopic imaging data showed a reduction in B-type carbonate and protein α-helices after a PMI of 3 years. The calculated mineral content ratio and the organic to mineral ratio displayed that the mineral content ratio increases, while the organic to mineral ratio decreases with time. Cluster-analyses of data from Raman microscopic imaging reconstructed histo-anatomical features in comparison to the light microscopic image and finally, by application of principal component analyses (PCA), it was possible to see a clear distinction between forensic and archaeological bone samples. Hence, the spectral characterization of inorganic and organic compounds by the afore mentioned techniques, followed by analyses such as multivariate imaging analysis (MIAs) and principal component analyses (PCA), appear to be suitable for the post mortem interval (PMI) estimation of human skeletal remains. PMID:28334006

Microtextured metals for stray-light suppression in the Clementine startracker

NASA Technical Reports Server (NTRS)

Johnson, E. A.

1993-01-01

Anodized blacks for suppressing stray light in optical systems can now be replaced by microscopically textured metal surfaces. An application of these black surfaces to the Clementine star-tracker navigational system, which will be launched in early 1994 to examine the Moon, en route to intercept an asteroid, is detailed. Rugged black surfaces with Lambertian BRDF less than 10(exp -2) srad(sup -1) are critical for suppressing stray light in the star-tracker optical train. Previously available materials spall under launch vibrations to contaminate mirrors and lenses. Microtextured aluminum is nearly as dark, but much less fragile. It is made by differential ion beam sputtering, which generates light-trapping pores and cones slightly smaller than the wavelength to be absorbed. This leaves a sturdy but light-absorbing surface that can survive challenging conditions without generating debris or contaminants. Both seeded ion beams and plasma immersion (from ECR plasmas) extraction can produce these microscopic textures without fragile interfaces. Process parameters control feature size, spacing, and optical effects (THR, BRDF). Both broad and narrow absorption bands can be engineered with tuning for specific wavelengths and applications. Examples are presented characterized by FTIR in reflection librators (0.95 normal emissivity), heat rejection, and enhanced nucleate boiling.

Morphology of the leather defect light flecks and spots.

PubMed

Nafstad, O; Wisløff, H; Grønstøl, H

2001-01-01

The skin histology and the scanning electron microscope morphology of the hide defect light flecks and spots after tanning were studied in 11 steers infested with biting lice (Damalinia bovis). Nine steers from herds free of lice were used as controls. Skin biopsies from 6 of the animals in the lice infested group showed mild to moderate hyperkeratosis and moderate perivascular to diffuse dermatitis with infiltration of mainly mononuclear cells and some eosinophilic granulocytes. The steers were slaughtered at an age of 18 to 23 months. Light flecks and spots occurred on all examined hides from the infested group after tanning. No examined hides from the control group demonstrated similar damage. Both light microscopic examination of sections of tanned hide with light flecks and spots and scanning electron microscopy of the same defects showed superficial grain loss and craters with a irregular fibre base encircled by smooth and intact grain. The association between louse infestation at an early age and damage of hides following slaughter 6 to 15 months later, suggested that louse infestations lead to a prolonged or lifelong weakening in the dermis. This weakening may cause superficial grain loss during the tanning process.

Morphology of the Leather Defect Light Flecks and Spots

PubMed Central

Nafstad, O; Wisløff, H; Grønstøl, H

2001-01-01

The skin histology and the scanning electron microscope morphology of the hide defect light flecks and spots after tanning were studied in 11 steers infested with biting lice (Damalinia bovis). Nine steers from herds free of lice were used as controls. Skin biopsies from 6 of the animals in the lice infested group showed mild to moderate hyperkeratosis and moderate perivascular to diffuse dermatitis with infiltration of mainly mononuclear cells and some eosinophilic granulocytes. The steers were slaughtered at an age of 18 to 23 months. Light flecks and spots occurred on all examined hides from the infested group after tanning. No examined hides from the control group demonstrated similar damage. Both light microscopic examination of sections of tanned hide with light flecks and spots and scanning electron microscopy of the same defects showed superficial grain loss and craters with a irregular fibre base encircled by smooth and intact grain. The association between louse infestation at an early age and damage of hides following slaughter 6 to 15 months later, suggested that louse infestations lead to a prolonged or lifelong weakening in the dermis. This weakening may cause superficial grain loss during the tanning process. PMID:11455890

Shearing interference microscope for step-height measurements.

PubMed

Trịnh, Hưng-Xuân; Lin, Shyh-Tsong; Chen, Liang-Chia; Yeh, Sheng-Lih; Chen, Chin-Sheng; Hoang, Hong-Hai

2017-05-01

A shearing interference microscope using a Savart prism as the shear plate is proposed for inspecting step-heights. Where the light beam propagates through the Savart prism and microscopic system to illuminate the sample, it then turns back to re-pass through the Savart prism and microscopic system to generate a shearing interference pattern on the camera. Two measurement modes, phase-shifting and phase-scanning, can be utilized to determine the depths of the step-heights on the sample. The first mode, which employs a narrowband source, is based on the five-step phase-shifting algorithm and has a measurement range of a quarter-wavelength. The second mode, which adopts a broadband source, is based on peak-intensity identification technology and has a measurement range up to a few micrometres. This paper is to introduce the configuration and measurement theory of this microscope, perform a setup used to implement it, and present the experimental results from the uses of the setup. The results not only verify the validity but also confirm the high measurement repeatability of the proposed microscope. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

A new computerized moving stage for optical microscopes

NASA Astrophysics Data System (ADS)

Hatiboglu, Can Ulas; Akin, Serhat

2004-06-01

Measurements of microscope stage movements in the x and y directions are of importance for some stereological methods. Traditionally, the length of stage movements is measured with differing precision and accuracy using a suitable motorized stage, a microscope and software. Such equipment is generally expensive and not readily available in many laboratories. One other challenging problem is the adaptability to available microscope systems which weakens the possibility of the equipment to be used with any kind of light microscope. This paper describes a simple and cheap programmable moving stage that can be used with the available microscopes in the market. The movements of the stage are controlled by two servo-motors and a controller chip via a Java-based image processing software. With the developed motorized stage and a microscope equipped with a CCD camera, the software allows complete coverage of the specimens with minimum overlap, eliminating the optical strain associated with counting hundreds of images through an eyepiece, in a quick and precise fashion. The uses and the accuracy of the developed stage are demonstrated using thin sections obtained from a limestone core plug.

Sizing and phenotyping of cellular vesicles using Nanoparticle Tracking Analysis

PubMed Central

Dragovic, Rebecca A.; Gardiner, Christopher; Brooks, Alexandra S.; Tannetta, Dionne S.; Ferguson, David J.P.; Hole, Patrick; Carr, Bob; Redman, Christopher W.G.; Harris, Adrian L.; Dobson, Peter J.; Harrison, Paul; Sargent, Ian L.

2011-01-01

Cellular microvesicles and nanovesicles (exosomes) are involved in many disease processes and have major potential as biomarkers. However, developments in this area are constrained by limitations in the technology available for their measurement. Here we report on the use of fluorescence nanoparticle tracking analysis (NTA) to rapidly size and phenotype cellular vesicles. In this system vesicles are visualized by light scattering using a light microscope. A video is taken, and the NTA software tracks the brownian motion of individual vesicles and calculates their size and total concentration. Using human placental vesicles and plasma, we have demonstrated that NTA can measure cellular vesicles as small as ∼50 nm and is far more sensitive than conventional flow cytometry (lower limit ∼300 nm). By combining NTA with fluorescence measurement we have demonstrated that vesicles can be labeled with specific antibody-conjugated quantum dots, allowing their phenotype to be determined. From the Clinical Editor The authors of this study utilized fluorescence nanoparticle tracking analysis (NTA) to rapidly size and phenotype cellular vesicles, demonstrating that NTA is far more sensitive than conventional flow cytometry. PMID:21601655

Biobeam—Multiplexed wave-optical simulations of light-sheet microscopy

PubMed Central

Weigert, Martin; Bundschuh, Sebastian T.

2018-01-01

Sample-induced image-degradation remains an intricate wave-optical problem in light-sheet microscopy. Here we present biobeam, an open-source software package that enables simulation of operational light-sheet microscopes by combining data from 105–106 multiplexed and GPU-accelerated point-spread-function calculations. The wave-optical nature of these simulations leads to the faithful reproduction of spatially varying aberrations, diffraction artifacts, geometric image distortions, adaptive optics, and emergent wave-optical phenomena, and renders image-formation in light-sheet microscopy computationally tractable. PMID:29652879

Polarized Light Microscopy

NASA Technical Reports Server (NTRS)

Frandsen, Athela F.

2016-01-01

Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often advised, If you cant determine a specific optical property of a particle after two minutes, move onto another configuration. Since optical properties can be seen so very quickly and easily under polarized light, it is only necessary to spend a maximum of two minutes on a technique to determine a particular property, though often only a few seconds are required.

Optical improvements in the diagnosis of bladder cancer: implications for clinical practice.

PubMed

Schubert, Tina; Rausch, Steffen; Fahmy, Omar; Gakis, Georgios; Stenzl, Arnulf

2017-11-01

For over 100 years white-light cystoscopy has remained the gold-standard technique for the detection of bladder cancer (BCa). Some limitations in the detection of flat lesions (CIS), the differentiation between inflammation and malignancy, the inaccurate determination of the tumor margin status as well as the tumor depth, have led to a variety of technological improvements. The aim of this review is to evaluate the impact of these improvements in the diagnosis of BCa and their effectiveness in clinical practice. A systematic literature search was conducted according to the PRISMA statement to identify studies reporting on imaging modalities in the diagnosis of NMIBC between 2000 and 2017. A two-stage selection process was utilized to determine eligible studies. A total of 74 studies were considered for final analysis. Optical imaging technologies have emerged as an adjunct to white-light cystoscopy and can be classified according to their scope as macroscopic, microscopic and molecular. Macroscopic techniques including photodynamic diagnosis (PDD), narrow-band imaging (NBI) and the Storz Professional Image Enhancement System (IMAGE1 S, formerly known as SPIES) are similar to white-light cystoscopy, but are superior in the detection of bladder tumors by means of contrast enhancement. Especially the detection rate of very mute lesions in the bladder mucosa (CIS) could be significantly increased by the use of these methods. Microscopic imaging techniques like confocal laser endomicroscopy and optical coherence tomography permit a real-time high-resolution assessment of the bladder mucosa at a cellular and sub-cellular level with spatial resolutions similar to histology, enabling the surgeon to perform an 'optical biopsy'. Molecular techniques are based on the combination of optical imaging technologies with fluorescence labeling of cancer-specific molecular agents like antibodies. This labeling is intended to favor an optical distinction between benign and malignant tissue. Optical improvements of the standard white-light cystoscopy have proven their benefit in the detection of BCa and have found their way into clinical practice. Especially the combination of macroscopic and microscopic techniques may improve diagnostic accuracy. Nevertheless, HAL-PDD guided cystoscopy is the only approach approved for routine use in the diagnosis of BCa by most urological associations in the EU and USA to date.

Testing a high-power LED based light source for hyperspectral imaging microscopy

NASA Astrophysics Data System (ADS)

Klomkaew, Phiwat; Mayes, Sam A.; Rich, Thomas C.; Leavesley, Silas J.

2017-02-01

Our lab has worked to develop high-speed hyperspectral imaging systems that scan the fluorescence excitation spectrum for biomedical imaging applications. Hyperspectral imaging can be used in remote sensing, medical imaging, reaction analysis, and other applications. Here, we describe the development of a hyperspectral imaging system that comprised an inverted Nikon Eclipse microscope, sCMOS camera, and a custom light source that utilized a series of high-power LEDs. LED selection was performed to achieve wavelengths of 350-590 nm. To reduce scattering, LEDs with low viewing angles were selected. LEDs were surface-mount soldered and powered by an RCD. We utilized 3D printed mounting brackets to assemble all circuit components. Spectraradiometric calibration was performed using a spectrometer (QE65000, Ocean Optics) and integrating sphere (FOIS-1, Ocean Optics). Optical output and LED driving current were measured over a range of illumination intensities. A normalization algorithm was used to calibrate and optimize the intensity of the light source. The highest illumination power was at 375 nm (3300 mW/cm2), while the lowest illumination power was at 515, 525, and 590 nm (5200 mW/cm2). Comparing the intensities supplied by each LED to the intensities measured at the microscope stage, we found there was a great loss in power output. Future work will focus on using two of the same LEDs to double the power and finding more LED and/or laser diodes and chips around the range. This custom hyperspectral imaging system could be used for the detection of cancer and the identification of biomolecules.

Semi-thin sections of epoxy resin-embedded mouse embryos in morphological analysis of whole mount in situ RNA hybridization.

PubMed

Mitrecić, D; Cunko, V F; Gajović, S

2008-12-01

Descriptive morphological studies are often combined with gene expression pattern analyses. Unembedded vibratome or cryotome sections are compatible with in situ RNA hybridization, but spatial resolution is rather low for precise microscopic studies necessary in embryology. Therefore, use of plastic embedding media, which allow semi-thin and ultra-thin sectioning for light and electron microscopy, could be an important advantage. This work suggested a new approach based on the whole mount hybridization of mouse embryos and subsequent epoxy resin embedding. Epoxy resin allowed serial sectioning of semi-thin sections with preserved in situ RNA hybridization signal, which was a necessary prerequisite for precise morphological analysis of embryo development.

Mueller matrix microscope: a quantitative tool to facilitate detections and fibrosis scorings of liver cirrhosis and cancer tissues.

PubMed

Wang, Ye; He, Honghui; Chang, Jintao; He, Chao; Liu, Shaoxiong; Li, Migao; Zeng, Nan; Wu, Jian; Ma, Hui

2016-07-01

Today the increasing cancer incidence rate is becoming one of the biggest threats to human health.Among all types of cancers, liver cancer ranks in the top five in both frequency and mortality rate all over the world. During the development of liver cancer, fibrosis often evolves as part of a healing process in response to liver damage, resulting in cirrhosis of liver tissues. In a previous study, we applied the Mueller matrix microscope to pathological liver tissue samples and found that both the Mueller matrix polar decomposition (MMPD) and Mueller matrix transformation (MMT) parameters are closely related to the fibrous microstructures. In this paper,we take this one step further to quantitatively facilitate the fibrosis detections and scorings of pathological liver tissue samples in different stages from cirrhosis to cancer using the Mueller matrix microscope. The experimental results of MMPD and MMT parameters for the fibrotic liver tissue samples in different stages are measured and analyzed. We also conduct Monte Carlo simulations based on the sphere birefringence model to examine in detail the influence of structural changes in different fibrosis stages on the imaging parameters. Both the experimental and simulated results indicate that the polarized light microscope and transformed Mueller matrix parameter scan provide additional quantitative information helpful for fibrosis detections and scorings of liver cirrhosis and cancers. Therefore, the polarized light microscope and transformed Mueller matrix parameters have a good application prospect in liver cancer diagnosis.

Mueller matrix microscope: a quantitative tool to facilitate detections and fibrosis scorings of liver cirrhosis and cancer tissues

NASA Astrophysics Data System (ADS)

Wang, Ye; He, Honghui; Chang, Jintao; He, Chao; Liu, Shaoxiong; Li, Migao; Zeng, Nan; Wu, Jian; Ma, Hui

2016-07-01

Today the increasing cancer incidence rate is becoming one of the biggest threats to human health. Among all types of cancers, liver cancer ranks in the top five in both frequency and mortality rate all over the world. During the development of liver cancer, fibrosis often evolves as part of a healing process in response to liver damage, resulting in cirrhosis of liver tissues. In a previous study, we applied the Mueller matrix microscope to pathological liver tissue samples and found that both the Mueller matrix polar decomposition (MMPD) and Mueller matrix transformation (MMT) parameters are closely related to the fibrous microstructures. In this paper, we take this one step further to quantitatively facilitate the fibrosis detections and scorings of pathological liver tissue samples in different stages from cirrhosis to cancer using the Mueller matrix microscope. The experimental results of MMPD and MMT parameters for the fibrotic liver tissue samples in different stages are measured and analyzed. We also conduct Monte Carlo simulations based on the sphere birefringence model to examine in detail the influence of structural changes in different fibrosis stages on the imaging parameters. Both the experimental and simulated results indicate that the polarized light microscope and transformed Mueller matrix parameters can provide additional quantitative information helpful for fibrosis detections and scorings of liver cirrhosis and cancers. Therefore, the polarized light microscope and transformed Mueller matrix parameters have a good application prospect in liver cancer diagnosis.

Identification of mycobacterium tuberculosis in sputum smear slide using automatic scanning microscope

NASA Astrophysics Data System (ADS)

Rulaningtyas, Riries; Suksmono, Andriyan B.; Mengko, Tati L. R.; Saptawati, Putri

2015-04-01

Sputum smear observation has an important role in tuberculosis (TB) disease diagnosis, because it needs accurate identification to avoid high errors diagnosis. In development countries, sputum smear slide observation is commonly done with conventional light microscope from Ziehl-Neelsen stained tissue and it doesn't need high cost to maintain the microscope. The clinicians do manual screening process for sputum smear slide which is time consuming and needs highly training to detect the presence of TB bacilli (mycobacterium tuberculosis) accurately, especially for negative slide and slide with less number of TB bacilli. For helping the clinicians, we propose automatic scanning microscope with automatic identification of TB bacilli. The designed system modified the field movement of light microscope with stepper motor which was controlled by microcontroller. Every sputum smear field was captured by camera. After that some image processing techniques were done for the sputum smear images. The color threshold was used for background subtraction with hue canal in HSV color space. Sobel edge detection algorithm was used for TB bacilli image segmentation. We used feature extraction based on shape for bacilli analyzing and then neural network classified TB bacilli or not. The results indicated identification of TB bacilli that we have done worked well and detected TB bacilli accurately in sputum smear slide with normal staining, but not worked well in over staining and less staining tissue slide. However, overall the designed system can help the clinicians in sputum smear observation becomes more easily.

Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams

PubMed Central

Guzzinati, Giulio; Béché, Armand; Lourenço-Martins, Hugo; Martin, Jérôme; Kociak, Mathieu; Verbeeck, Jo

2017-01-01

Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations' symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations' symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria. PMID:28401942

Nondestructive measurement of an optical fiber refractive-index profile by a transmitted-light differential interference contact microscope.

PubMed

Liu, Zhongyao; Dong, Xiaoman; Chen, Qianghua; Yin, Chunyong; Xu, Yuxian; Zheng, Yingjun

2004-03-01

A novel transmitted-light differential interference contrast (DIC) system is used for nondestructive measurement of the refractive-index profile (RIP) of an optical fiber. By means of this system the phase of a measured light beam can be modulated with an analyzer, and the phase distribution of a fiber is obtained by calculation of the various interference patterns. The measurement theory and structure and some typical applications of this system are demonstrated. The results of measuring RIPs in graded-index fiber are presented. Both the experimental results and theoretical analysis show that the system takes the advantage of high index resolution and of sufficient measurement accuracy for measuring the refractive index of the optical fiber. The system has strong ability to overcome environmental disturbance because of its common-path design. Moreover, one can use the system to measure the RIP along the fiber axis and acquire an image of the three-dimensional RIP of the fiber.

Microscopic Analysis of Activated Sludge. Training Manual.

ERIC Educational Resources Information Center

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

Quantitative readout of optically encoded gold nanorods using an ordinary dark-field microscope.

PubMed

Mercatelli, Raffaella; Ratto, Fulvio; Centi, Sonia; Soria, Silvia; Romano, Giovanni; Matteini, Paolo; Quercioli, Franco; Pini, Roberto; Fusi, Franco

2013-10-21

In this paper we report on a new use for dark-field microscopy in order to retrieve two-dimensional maps of optical parameters of a thin sample such as a cryptograph, a histological section, or a cell monolayer. In particular, we discuss the construction of quantitative charts of light absorbance and scattering coefficients of a polyvinyl alcohol film that was embedded with gold nanorods and then etched using a focused mode-locked Ti:Sapphire oscillator. Individual pulses from this laser excite plasmonic oscillations of the gold nanorods, thus triggering plastic deformations of the particles and their environment, which are confined within a few hundred nm of the light focus. In turn, these deformations modify the light absorbance and scattering landscape, which can be measured with optical resolution in a dark-field microscope equipped with an objective of tuneable numerical aperture. This technique may prove to be valuable for various applications, such as the fast readout of optically encoded data or to model functional interactions between light and biological tissue at the level of cellular organelles, including the photothermolysis of cancer.

Fractal propagation method enables realistic optical microscopy simulations in biological tissues

PubMed Central

Glaser, Adam K.; Chen, Ye; Liu, Jonathan T.C.

2017-01-01

Current simulation methods for light transport in biological media have limited efficiency and realism when applied to three-dimensional microscopic light transport in biological tissues with refractive heterogeneities. We describe here a technique which combines a beam propagation method valid for modeling light transport in media with weak variations in refractive index, with a fractal model of refractive index turbulence. In contrast to standard simulation methods, this fractal propagation method (FPM) is able to accurately and efficiently simulate the diffraction effects of focused beams, as well as the microscopic heterogeneities present in tissue that result in scattering, refractive beam steering, and the aberration of beam foci. We validate the technique and the relationship between the FPM model parameters and conventional optical parameters used to describe tissues, and also demonstrate the method’s flexibility and robustness by examining the steering and distortion of Gaussian and Bessel beams in tissue with comparison to experimental data. We show that the FPM has utility for the accurate investigation and optimization of optical microscopy methods such as light-sheet, confocal, and nonlinear microscopy. PMID:28983499

Plum pudding random medium model of biological tissue toward remote microscopy from spectroscopic light scattering

PubMed Central

Xu, Min

2017-01-01

Biological tissue has a complex structure and exhibits rich spectroscopic behavior. There has been no tissue model until now that has been able to account for the observed spectroscopy of tissue light scattering and its anisotropy. Here we present, for the first time, a plum pudding random medium (PPRM) model for biological tissue which succinctly describes tissue as a superposition of distinctive scattering structures (plum) embedded inside a fractal continuous medium of background refractive index fluctuation (pudding). PPRM faithfully reproduces the wavelength dependence of tissue light scattering and attributes the “anomalous” trend in the anisotropy to the plum and the powerlaw dependence of the reduced scattering coefficient to the fractal scattering pudding. Most importantly, PPRM opens up a novel venue of quantifying the tissue architecture and microscopic structures on average from macroscopic probing of the bulk with scattered light alone without tissue excision. We demonstrate this potential by visualizing the fine microscopic structural alterations in breast tissue (adipose, glandular, fibrocystic, fibroadenoma, and ductal carcinoma) deduced from noncontact spectroscopic measurement. PMID:28663913

Is in vivo analysis of urinary stone composition feasible? Evaluation of an experimental setup of a Raman system coupled to commercial lithotripsy laser fibers.

PubMed

Miernik, Arkadiusz; Eilers, Yvan; Nuese, Christoph; Bolwien, Carsten; Lambrecht, Armin; Hesse, Albrecht; Rassweiler, Jens J; Schlager, Daniel; Wilhelm, Konrad; Wetterauer, Ulrich; Schoenthaler, Martin

2015-10-01

Raman spectroscopy allows immediate analysis of stone composition. In vivo stone analysis during endoscopic treatment may offer advantages concerning surgical strategy and metaphylaxis. Urinary stone components were evaluated utilizing an experimental setup of a Raman system coupled to commercial laser fibers. Samples of paracetamol (acetaminophen) and human urinary stones with known Raman spectra were analyzed using an experimental Raman system coupled to common commercial lithotripsy laser fibers (200 and 940 µm). Two different excitation lasers were used at wavelengths of 532 and 785 nm. Numerical aperture of the fibers, proportion of reflected light reaching the CCD chip, and integration times were calculated. Mathematical signal correction was performed. Both the laser beam profile and the quality of light reflected by the specimens were impaired significantly when used with commercial fibers. Acquired spectra could no longer be assigned to a specific stone composition. Subsequent measurements revealed a strong intrinsic fluorescence of the fibers and poor light acquisition properties leading to a significant decrease in the Raman signal in comparison with a free-beam setup. This was true for both investigated fiber diameters and both wavelengths. Microscopic examination showed highly irregular fiber tip surfaces (both new and used fibers). Our results propose that laser excitation and light acquisition properties of commercial lithotripsy fibers impair detectable Raman signals significantly in a fiber-coupled setting. This study provides essential physical and technological information for the development of an advanced fiber-coupled system able to be used for immediate stone analysis during endoscopic stone therapy.

Dynamic views of living cell fine structure revealed by birefringence imaging

NASA Astrophysics Data System (ADS)

Oldenbourg, Rudolf

2001-11-01

We have been developing and applying a new type of polarized light microscope, the new Pol-Scope, which dramatically enhances the unique capabilities of the traditional polarizing microscope. In living cells, without applying exogenous dyes or florescent labels, we have studied the dynamic organization of filamentous actin in neuronal growth cones and improved the efficiency of spindle imaging for in-vitro fertilization and enucleation procedures.

Light field creating and imaging with different order intensity derivatives

NASA Astrophysics Data System (ADS)

Wang, Yu; Jiang, Huan

2014-10-01

Microscopic image restoration and reconstruction is a challenging topic in the image processing and computer vision, which can be widely applied to life science, biology and medicine etc. A microscopic light field creating and three dimensional (3D) reconstruction method is proposed for transparent or partially transparent microscopic samples, which is based on the Taylor expansion theorem and polynomial fitting. Firstly the image stack of the specimen is divided into several groups in an overlapping or non-overlapping way along the optical axis, and the first image of every group is regarded as reference image. Then different order intensity derivatives are calculated using all the images of every group and polynomial fitting method based on the assumption that the structure of the specimen contained by the image stack in a small range along the optical axis are possessed of smooth and linear property. Subsequently, new images located any position from which to reference image the distance is Δz along the optical axis can be generated by means of Taylor expansion theorem and the calculated different order intensity derivatives. Finally, the microscopic specimen can be reconstructed in 3D form using deconvolution technology and all the images including both the observed images and the generated images. The experimental results show the effectiveness and feasibility of our method.

Integrative Advances for OCT-Guided Ophthalmic Surgery and Intraoperative OCT: Microscope Integration, Surgical Instrumentation, and Heads-Up Display Surgeon Feedback

PubMed Central

Ehlers, Justis P.; Srivastava, Sunil K.; Feiler, Daniel; Noonan, Amanda I.; Rollins, Andrew M.; Tao, Yuankai K.

2014-01-01

Purpose To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. Methods We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. Results High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Conclusions Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated. PMID:25141340

In-situ microwave synthesis of graphene-TiO2 nanocomposites with enhanced photocatalytic properties for the degradation of organic pollutants.

PubMed

Shanmugam, Mahalingam; Alsalme, Ali; Alghamdi, Abdulaziz; Jayavel, Ramasamy

2016-10-01

Graphene-titanium oxide (G-TiO2) nanocomposites were synthesized by a novel surfactant free, environmentally friendly one-port in-situ microwave method. The structure of the nanocomposite was characterized by the X-ray diffraction analysis and the morphology by using scanning electron microscopic and transmission electron microscopic images. The functional groups and carbon band structures were identified using FTIR and Raman spectral analysis. TiO2 nanoparticles in the size range of 5-10nm were distributed on the graphene sheets. The surface area of pure TiO2 and G-TiO2 nanocomposite was measured to be 20.11 and 173.76m(2)/g respectively. The pore volume and pore size of TiO2 were 0.018cm(3)/g and 1.5266nm respectively. G-TiO2 composite possesses higher pore volume (0.259cm(3)/g) and pore size 3.2075nm. The binding states of C, O and Ti of nanocomposite were analyzed by X-ray photoelectron spectroscopy, which confirmed the chemical bonding between graphene-TiO2. The photocatalytic activity of pure TiO2 and G-TiO2 nanocomposite was studied under UV and visible light irradiation sources with methylene blue dye. It has been observed that the degradation was faster in G-TiO2 nanocomposite than pure TiO2 nanoparticles. The rate constant and half life time were calculated from the kinetic studies of the degradation. The highest degradation efficiency of 97% was achieved in UV light and 96% for visible light irradiation with G-TiO2 as a catalyst. The studies reveal that G-TiO2 nanocomposite can be an effective catalyst for industrial waste water treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging C. elegans embryos using an epifluorescent microscope and open source software.

PubMed

Verbrugghe, Koen J C; Chan, Raymond C

2011-03-24

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using fluorescent-labeled reporter proteins or differential interference contrast (DIC) microscopy, allows for the examination of the temporal progression of these dynamic events which is otherwise inferred from analysis of fixed samples(1,2). Moreover, the study of the developmental regulations of cellular processes necessitates conducting time-lapse experiments on an intact organism during development. The Caenorhabiditis elegans embryo is light-transparent and has a rapid, invariant developmental program with a known cell lineage(3), thus providing an ideal experiment model for studying questions in cell biology(4,5)and development(6-9). C. elegans is amendable to genetic manipulation by forward genetics (based on random mutagenesis(10,11)) and reverse genetics to target specific genes (based on RNAi-mediated interference and targeted mutagenesis(12-15)). In addition, transgenic animals can be readily created to express fluorescently tagged proteins or reporters(16,17). These traits combine to make it easy to identify the genetic pathways regulating fundamental cellular and developmental processes in vivo(18-21). In this protocol we present methods for live imaging of C. elegans embryos using DIC optics or GFP fluorescence on a compound epifluorescent microscope. We demonstrate the ease with which readily available microscopes, typically used for fixed sample imaging, can also be applied for time-lapse analysis using open-source software to automate the imaging process.

Detection of microscopic particles present as contaminants in latent fingerprints by means of synchrotron radiation-based Fourier transform infra-red micro-imaging.

PubMed

Banas, A; Banas, K; Breese, M B H; Loke, J; Heng Teo, B; Lim, S K

2012-08-07

Synchrotron radiation-based Fourier transform infra-red (SR-FTIR) micro-imaging has been developed as a rapid, direct and non-destructive technique. This method, taking advantage of the high brightness and small effective source size of synchrotron light, is capable of exploring the molecular chemistry within the microstructures of microscopic particles without their destruction at high spatial resolutions. This is in contrast to traditional "wet" chemical methods, which, during processing for analysis, often caused destruction of the original samples. In the present study, we demonstrate the potential of SR-FTIR micro-imaging as an effective way to accurately identify microscopic particles deposited within latent fingerprints. These particles are present from residual amounts of materials left on a person's fingers after handling such materials. Fingerprints contaminated with various types of powders, creams, medications and high explosive materials (3-nitrooxy-2,2-bis(nitrooxymethyl)propyl nitrate (PETN), 1,3,5-trinitro-1,3,5-triazinane (RDX), 2-methyl-1,3,5-trinitrobenzene (TNT)) deposited on various - daily used - substrates have been analysed herein without any further sample preparation. A non-destructive method for the transfer of contaminated fingerprints from hard-to-reach areas of the substrates to the place of analysis is also presented. This method could have a significant impact on forensic science and could dramatically enhance the amount of information that can be obtained from the study of fingerprints.

Bessel light sheet structured illumination microscopy

NASA Astrophysics Data System (ADS)

Noshirvani Allahabadi, Golchehr

Biomedical study researchers using animals to model disease and treatment need fast, deep, noninvasive, and inexpensive multi-channel imaging methods. Traditional fluorescence microscopy meets those criteria to an extent. Specifically, two-photon and confocal microscopy, the two most commonly used methods, are limited in penetration depth, cost, resolution, and field of view. In addition, two-photon microscopy has limited ability in multi-channel imaging. Light sheet microscopy, a fast developing 3D fluorescence imaging method, offers attractive advantages over traditional two-photon and confocal microscopy. Light sheet microscopy is much more applicable for in vivo 3D time-lapsed imaging, owing to its selective illumination of tissue layer, superior speed, low light exposure, high penetration depth, and low levels of photobleaching. However, standard light sheet microscopy using Gaussian beam excitation has two main disadvantages: 1) the field of view (FOV) of light sheet microscopy is limited by the depth of focus of the Gaussian beam. 2) Light-sheet images can be degraded by scattering, which limits the penetration of the excitation beam and blurs emission images in deep tissue layers. While two-sided sheet illumination, which doubles the field of view by illuminating the sample from opposite sides, offers a potential solution, the technique adds complexity and cost to the imaging system. We investigate a new technique to address these limitations: Bessel light sheet microscopy in combination with incoherent nonlinear Structured Illumination Microscopy (SIM). Results demonstrate that, at visible wavelengths, Bessel excitation penetrates up to 250 microns deep in the scattering media with single-side illumination. Bessel light sheet microscope achieves confocal level resolution at a lateral resolution of 0.3 micron and an axial resolution of 1 micron. Incoherent nonlinear SIM further reduces the diffused background in Bessel light sheet images, resulting in confocal quality images in thick tissue. The technique was applied to live transgenic zebra fish tg(kdrl:GFP), and the sub-cellular structure of fish vasculature genetically labeled with GFP was captured in 3D. The superior speed of the microscope enables us to acquire signal from 200 layers of a thick sample in 4 minutes. The compact microscope uses exclusively off-the-shelf components and offers a low-cost imaging solution for studying small animal models or tissue samples.

Optimisation approaches for concurrent transmitted light imaging during confocal microscopy.

PubMed

Collings, David A

2015-01-01

The transmitted light detectors present on most modern confocal microscopes are an under-utilised tool for the live imaging of plant cells. As the light forming the image in this detector is not passed through a pinhole, out-of-focus light is not removed. It is this extended focus that allows the transmitted light image to provide cellular and organismal context for fluorescence optical sections generated confocally. More importantly, the transmitted light detector provides images that have spatial and temporal registration with the fluorescence images, unlike images taken with a separately-mounted camera. Because plants often provide difficulties for taking transmitted light images, with the presence of pigments and air pockets in leaves, this study documents several approaches to improving transmitted light images beginning with ensuring that the light paths through the microscope are correctly aligned (Köhler illumination). Pigmented samples can be imaged in real colour using sequential scanning with red, green and blue lasers. The resulting transmitted light images can be optimised and merged in ImageJ to generate colour images that maintain registration with concurrent fluorescence images. For faster imaging of pigmented samples, transmitted light images can be formed with non-absorbed wavelengths. Transmitted light images of Arabidopsis leaves expressing GFP can be improved by concurrent illumination with green and blue light. If the blue light used for YFP excitation is blocked from the transmitted light detector with a cheap, coloured glass filters, the non-absorbed green light will form an improved transmitted light image. Changes in sample colour can be quantified by transmitted light imaging. This has been documented in red onion epidermal cells where changes in vacuolar pH triggered by the weak base methylamine result in measurable colour changes in the vacuolar anthocyanin. Many plant cells contain visible levels of pigment. The transmitted light detector provides a useful tool for documenting and measuring changes in these pigments while maintaining registration with confocal imaging.

An automatic device for detection and classification of malaria parasite species in thick blood film.

PubMed

Kaewkamnerd, Saowaluck; Uthaipibull, Chairat; Intarapanich, Apichart; Pannarut, Montri; Chaotheing, Sastra; Tongsima, Sissades

2012-01-01

Current malaria diagnosis relies primarily on microscopic examination of Giemsa-stained thick and thin blood films. This method requires vigorously trained technicians to efficiently detect and classify the malaria parasite species such as Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) for an appropriate drug administration. However, accurate classification of parasite species is difficult to achieve because of inherent technical limitations and human inconsistency. To improve performance of malaria parasite classification, many researchers have proposed automated malaria detection devices using digital image analysis. These image processing tools, however, focus on detection of parasites on thin blood films, which may not detect the existence of parasites due to the parasite scarcity on the thin blood film. The problem is aggravated with low parasitemia condition. Automated detection and classification of parasites on thick blood films, which contain more numbers of parasite per detection area, would address the previous limitation. The prototype of an automatic malaria parasite identification system is equipped with mountable motorized units for controlling the movements of objective lens and microscope stage. This unit was tested for its precision to move objective lens (vertical movement, z-axis) and microscope stage (in x- and y-horizontal movements). The average precision of x-, y- and z-axes movements were 71.481 ± 7.266 μm, 40.009 ± 0.000 μm, and 7.540 ± 0.889 nm, respectively. Classification of parasites on 60 Giemsa-stained thick blood films (40 blood films containing infected red blood cells and 20 control blood films of normal red blood cells) was tested using the image analysis module. By comparing our results with the ones verified by trained malaria microscopists, the prototype detected parasite-positive and parasite-negative blood films at the rate of 95% and 68.5% accuracy, respectively. For classification performance, the thick blood films with Pv parasite was correctly classified with the success rate of 75% while the accuracy of Pf classification was 90%. This work presents an automatic device for both detection and classification of malaria parasite species on thick blood film. The system is based on digital image analysis and featured with motorized stage units, designed to easily be mounted on most conventional light microscopes used in the endemic areas. The constructed motorized module could control the movements of objective lens and microscope stage at high precision for effective acquisition of quality images for analysis. The analysis program could accurately classify parasite species, into Pf or Pv, based on distribution of chromatin size.

Light and life in Baltimore--and beyond.

PubMed

Edidin, Michael

2015-02-03

Baltimore has been the home of numerous biophysical studies using light to probe cells. One such study, quantitative measurement of lateral diffusion of rhodopsin, set the standard for experiments in which recovery after photobleaching is used to measure lateral diffusion. Development of this method from specialized microscopes to commercial scanning confocal microscopes has led to widespread use of the technique to measure lateral diffusion of membrane proteins and lipids, and as well diffusion and binding interactions in cell organelles and cytoplasm. Perturbation of equilibrium distributions by photobleaching has also been developed into a robust method to image molecular proximity in terms of fluorescence resonance energy transfer between donor and acceptor fluorophores. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[Electron microscopic study of the An-750 strain of Powassan virus isolated in the Soviet Union].

PubMed

Sobolev, S G; Shestopalova, N M; Linev, M B; Rubin, S G

1978-01-01

Electron microscopic examinations of brains of white mice inoculated with the An 750 strain isolated for the first time from adult mosquitoes and with the prototype LB strain of Powassan virus were carried out. The method of combination of light and electron microscopy used in the study permitted to compare ultrastructural changes in one cell with the results of light microscopy. Sizes of virions and their localizations in the brain cells were determined. Virus particles were found in large and small neurons as well as in glial elements. Subcellular changes in neurons associated with virus multiplication are described. The causes of differences in sizes of virions measured in ultrathin sections are discussed.

Three-dimensional microscopic tomographic imagings of the cataract in a human lens in vivo

NASA Astrophysics Data System (ADS)

Masters, Barry R.

1998-10-01

The problem of three-dimensional visualization of a human lens in vivo has been solved by a technique of volume rendering a transformed series of 60 rotated Scheimpflug (a dual slit reflected light microscope) digital images. The data set was obtained by rotating the Scheimpflug camera about the optic axis of the lens in 3 degree increments. The transformed set of optical sections were first aligned to correct for small eye movements, and then rendered into a volume reconstruction with volume rendering computer graphics techniques. To help visualize the distribution of lens opacities (cataracts) in the living, human lens the intensity of light scattering was pseudocolor coded and the cataract opacities were displayed as a movie.

Full in-vitro analyses of new-generation bulk fill dental composites cured by halogen light.

PubMed

Tekin, Tuçe Hazal; Kantürk Figen, Aysel; Yılmaz Atalı, Pınar; Coşkuner Filiz, Bilge; Pişkin, Mehmet Burçin

2017-08-01

The objective of this study was to investigate the full in-vitro analyses of new-generation bulk-fill dental composites cured by halogen light (HLG). Two types' four composites were studied: Surefill SDR (SDR) and Xtra Base (XB) as bulk-fill flowable materials; QuixFill (QF) and XtraFill (XF) as packable bulk-fill materials. Samples were prepared for each analysis and test by applying the same procedure, but with different diameters and thicknesses appropriate to the analysis and test requirements. Thermal properties were determined by thermogravimetric analysis (TG/DTG) and differential scanning calorimetry (DSC) analysis; the Vickers microhardness (VHN) was measured after 1, 7, 15 and 30days of storage in water. The degree of conversion values for the materials (DC, %) were immediately measured using near-infrared spectroscopy (FT-IR). The surface morphology of the composites was investigated by scanning electron microscopes (SEM) and atomic-force microscopy (AFM) analyses. The sorption and solubility measurements were also performed after 1, 7, 15 and 30days of storage in water. In addition to his, the data were statistically analyzed using one-way analysis of variance, and both the Newman Keuls and Tukey multiple comparison tests. The statistical significance level was established at p<0.05. According to the ISO 4049 standards, all the tested materials showed acceptable water sorption and solubility, and a halogen light source was an option to polymerize bulk-fill, resin-based dental composites. Copyright © 2017 Elsevier B.V. All rights reserved.

Non-label bioimaging utilizing scattering lights

NASA Astrophysics Data System (ADS)

Watanabe, Tomonobu M.; Ichimura, Taro; Fujita, Hideaki

2017-04-01

Optical microscopy is an indispensable tool for medical and life sciences. Especially, the microscopes utilized with scattering light offer a detailed internal observation of living specimens in real time because of their non-labeling and non-invasive capability. We here focus on two kinds of scattering lights, Raman scattering light and second harmonic generation light. Raman scattering light includes the information of all the molecular vibration modes of the molecules, and can be used to distinguish types and/or state of cell. Second harmonic generation light is derived from electric polarity of proteins in the specimen, and enables to detect their structural change. In this conference, we would like to introduce our challenges to extract biological information from those scattering lights.

A stand-alone compact EUV microscope based on gas-puff target source.

PubMed

Torrisi, Alfio; Wachulak, Przemyslaw; Węgrzyński, Łukasz; Fok, Tomasz; Bartnik, Andrzej; Parkman, Tomáš; Vondrová, Šárka; Turňová, Jana; Jankiewicz, Bartłomiej J; Bartosewicz, Bartosz; Fiedorowicz, Henryk

2017-02-01

We report on a very compact desk-top transmission extreme ultraviolet (EUV) microscope based on a laser-plasma source with a double stream gas-puff target, capable of acquiring magnified images of objects with a spatial (half-pitch) resolution of sub-50 nm. A multilayer ellipsoidal condenser is used to focus and spectrally narrow the radiation from the plasma, producing a quasi-monochromatic EUV radiation (λ = 13.8 nm) illuminating the object, whereas a Fresnel zone plate objective forms the image. Design details, development, characterization and optimization of the EUV source and the microscope are described and discussed. Test object and other samples were imaged to demonstrate superior resolution compared to visible light microscopy. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Charge transport mechanism analysis of Al/CdS:Sr{sup 2+}/ITO device under dark and light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datta, Joydeep; Das, Mrinmay; Dey, Arka

2016-05-06

In this study, we have synthesized CdS:Sr{sup 2+} by hydrothermal technique. Material property has been studied by X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-vis absorption spectroscopy. XRD data revealed that there are mixed phases of CdS and SrS in the synthesized sample. The optical band gap of the material was estimated as 3.15 eV from UV-vis data. The synthesized material has been applied in metal-semiconductor device and transport properties have been analyzed by measuring current–voltage characteristics under dark and light conditions at room temperature. Variation in different device parameters like ideality factor, barrier height and series resistance ofmore » Al/CdS:Sr{sup 2+}/ITO device were analyzed by using Cheung’s function.« less

Improving high resolution retinal image quality using speckle illumination HiLo imaging

PubMed Central

Zhou, Xiaolin; Bedggood, Phillip; Metha, Andrew

2014-01-01

Retinal image quality from flood illumination adaptive optics (AO) ophthalmoscopes is adversely affected by out-of-focus light scatter due to the lack of confocality. This effect is more pronounced in small eyes, such as that of rodents, because the requisite high optical power confers a large dioptric thickness to the retina. A recently-developed structured illumination microscopy (SIM) technique called HiLo imaging has been shown to reduce the effect of out-of-focus light scatter in flood illumination microscopes and produce pseudo-confocal images with significantly improved image quality. In this work, we adopted the HiLo technique to a flood AO ophthalmoscope and performed AO imaging in both (physical) model and live rat eyes. The improvement in image quality from HiLo imaging is shown both qualitatively and quantitatively by using spatial spectral analysis. PMID:25136486

Improving high resolution retinal image quality using speckle illumination HiLo imaging.

PubMed

Zhou, Xiaolin; Bedggood, Phillip; Metha, Andrew

2014-08-01

Retinal image quality from flood illumination adaptive optics (AO) ophthalmoscopes is adversely affected by out-of-focus light scatter due to the lack of confocality. This effect is more pronounced in small eyes, such as that of rodents, because the requisite high optical power confers a large dioptric thickness to the retina. A recently-developed structured illumination microscopy (SIM) technique called HiLo imaging has been shown to reduce the effect of out-of-focus light scatter in flood illumination microscopes and produce pseudo-confocal images with significantly improved image quality. In this work, we adopted the HiLo technique to a flood AO ophthalmoscope and performed AO imaging in both (physical) model and live rat eyes. The improvement in image quality from HiLo imaging is shown both qualitatively and quantitatively by using spatial spectral analysis.

Imaging, microscopic analysis, and modeling of a CdTe module degraded by heat and light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, Steve; Albin, David; Hacke, Peter

Photoluminescence (PL), electroluminescence (EL), and dark lock-in thermography are collected during stressing of a CdTe module under one-Sun light at an elevated temperature of 100 degrees C. The PL imaging system is simple and economical. The PL images show differing degrees of degradation across the module and are less sensitive to effects of shunting and resistance that appear on the EL images. Regions of varying degradation are chosen based on avoiding pre-existing shunt defects. These regions are evaluated using time-of-flight secondary ion-mass spectrometry and Kelvin probe force microscopy. Reduced PL intensity correlates to increased Cu concentration at the front interface.more » Numerical modeling and measurements agree that the increased Cu concentration at the junction also correlates to a reduced space charge region.« less

Imaging, microscopic analysis, and modeling of a CdTe module degraded by heat and light

DOE PAGES

Johnston, Steve; Albin, David; Hacke, Peter; ...

2018-01-12

Photoluminescence (PL), electroluminescence (EL), and dark lock-in thermography are collected during stressing of a CdTe module under one-Sun light at an elevated temperature of 100 degrees C. The PL imaging system is simple and economical. The PL images show differing degrees of degradation across the module and are less sensitive to effects of shunting and resistance that appear on the EL images. Regions of varying degradation are chosen based on avoiding pre-existing shunt defects. These regions are evaluated using time-of-flight secondary ion-mass spectrometry and Kelvin probe force microscopy. Reduced PL intensity correlates to increased Cu concentration at the front interface.more » Numerical modeling and measurements agree that the increased Cu concentration at the junction also correlates to a reduced space charge region.« less

Super-Resolution Imaging Strategies for Cell Biologists Using a Spinning Disk Microscope

PubMed Central

Hosny, Neveen A.; Song, Mingying; Connelly, John T.; Ameer-Beg, Simon; Knight, Martin M.; Wheeler, Ann P.

2013-01-01

In this study we use a spinning disk confocal microscope (SD) to generate super-resolution images of multiple cellular features from any plane in the cell. We obtain super-resolution images by using stochastic intensity fluctuations of biological probes, combining Photoactivation Light-Microscopy (PALM)/Stochastic Optical Reconstruction Microscopy (STORM) methodologies. We compared different image analysis algorithms for processing super-resolution data to identify the most suitable for analysis of particular cell structures. SOFI was chosen for X and Y and was able to achieve a resolution of ca. 80 nm; however higher resolution was possible >30 nm, dependant on the super-resolution image analysis algorithm used. Our method uses low laser power and fluorescent probes which are available either commercially or through the scientific community, and therefore it is gentle enough for biological imaging. Through comparative studies with structured illumination microscopy (SIM) and widefield epifluorescence imaging we identified that our methodology was advantageous for imaging cellular structures which are not immediately at the cell-substrate interface, which include the nuclear architecture and mitochondria. We have shown that it was possible to obtain two coloured images, which highlights the potential this technique has for high-content screening, imaging of multiple epitopes and live cell imaging. PMID:24130668

Imaging chromatin nanostructure with binding-activated localization microscopy based on DNA structure fluctuations

PubMed Central

Szczurek, Aleksander; Klewes, Ludger; Xing, Jun; Gourram, Amine; Birk, Udo; Knecht, Hans; Dobrucki, Jurek W.; Mai, Sabine

2017-01-01

Abstract Advanced light microscopy is an important tool for nanostructure analysis of chromatin. In this report we present a general concept for Single Molecule localization Microscopy (SMLM) super-resolved imaging of DNA-binding dyes based on modifying the properties of DNA and the dye. By careful adjustment of the chemical environment leading to local, reversible DNA melting and hybridization control over the fluorescence signal of the DNA-binding dye molecules can be introduced. We postulate a transient binding as the basis for our variation of binding-activated localization microscopy (BALM). We demonstrate that several intercalating and minor-groove binding DNA dyes can be used to register (optically isolate) only a few DNA-binding dye signals at a time. To highlight this DNA structure fluctuation-assisted BALM (fBALM), we applied it to measure, for the first time, nanoscale differences in nuclear architecture in model ischemia with an anticipated structural resolution of approximately 50 nm. Our data suggest that this approach may open an avenue for the enhanced microscopic analysis of chromatin nano-architecture and hence the microscopic analysis of nuclear structure aberrations occurring in various pathological conditions. It may also become possible to analyse nuclear nanostructure differences in different cell types, stages of development or environmental stress conditions. PMID:28082388

Extended morphological processing: a practical method for automatic spot detection of biological markers from microscopic images.

PubMed

Kimori, Yoshitaka; Baba, Norio; Morone, Nobuhiro

2010-07-08

A reliable extraction technique for resolving multiple spots in light or electron microscopic images is essential in investigations of the spatial distribution and dynamics of specific proteins inside cells and tissues. Currently, automatic spot extraction and characterization in complex microscopic images poses many challenges to conventional image processing methods. A new method to extract closely located, small target spots from biological images is proposed. This method starts with a simple but practical operation based on the extended morphological top-hat transformation to subtract an uneven background. The core of our novel approach is the following: first, the original image is rotated in an arbitrary direction and each rotated image is opened with a single straight line-segment structuring element. Second, the opened images are unified and then subtracted from the original image. To evaluate these procedures, model images of simulated spots with closely located targets were created and the efficacy of our method was compared to that of conventional morphological filtering methods. The results showed the better performance of our method. The spots of real microscope images can be quantified to confirm that the method is applicable in a given practice. Our method achieved effective spot extraction under various image conditions, including aggregated target spots, poor signal-to-noise ratio, and large variations in the background intensity. Furthermore, it has no restrictions with respect to the shape of the extracted spots. The features of our method allow its broad application in biological and biomedical image information analysis.

Middle School Science Notes

ERIC Educational Resources Information Center

School Science Review, 1976

1976-01-01

Describes a lighted demonstration apparatus for representing the distribution of electrons, protons and neutrons in an atom. Also includes experiments with ice, forces, microscopes, spectra, and geological modeling. (CS)

A simple method for the extraction and identification of light density microplastics from soil.

PubMed

Zhang, Shaoliang; Yang, Xiaomei; Gertsen, Hennie; Peters, Piet; Salánki, Tamás; Geissen, Violette

2018-03-01

This article introduces a simple and cost-saving method developed to extract, distinguish and quantify light density microplastics of polyethylene (PE) and polypropylene (PP) in soil. A floatation method using distilled water was used to extract the light density microplastics from soil samples. Microplastics and impurities were identified using a heating method (3-5s at 130°C). The number and size of particles were determined using a camera (Leica DFC 425) connected to a microscope (Leica wild M3C, Type S, simple light, 6.4×). Quantification of the microplastics was conducted using a developed model. Results showed that the floatation method was effective in extracting microplastics from soils, with recovery rates of approximately 90%. After being exposed to heat, the microplastics in the soil samples melted and were transformed into circular transparent particles while other impurities, such as organic matter and silicates were not changed by the heat. Regression analysis of microplastics weight and particle volume (a calculation based on image J software analysis) after heating showed the best fit (y=1.14x+0.46, R 2 =99%, p<0.001). Recovery rates based on the empirical model method were >80%. Results from field samples collected from North-western China prove that our method of repetitive floatation and heating can be used to extract, distinguish and quantify light density polyethylene microplastics in soils. Microplastics mass can be evaluated using the empirical model. Copyright © 2017 Elsevier B.V. All rights reserved.

White light phase shifting interferometry and color fringe analysis for the detection of contaminants in water

NASA Astrophysics Data System (ADS)

Dubey, Vishesh; Singh, Veena; Ahmad, Azeem; Singh, Gyanendra; Mehta, Dalip Singh

2016-03-01

We report white light phase shifting interferometry in conjunction with color fringe analysis for the detection of contaminants in water such as Escherichia coli (E.coli), Campylobacter coli and Bacillus cereus. The experimental setup is based on a common path interferometer using Mirau interferometric objective lens. White light interferograms are recorded using a 3-chip color CCD camera based on prism technology. The 3-chip color camera have lesser color cross talk and better spatial resolution in comparison to single chip CCD camera. A piezo-electric transducer (PZT) phase shifter is fixed with the Mirau objective and they are attached with a conventional microscope. Five phase shifted white light interferograms are recorded by the 3-chip color CCD camera and each phase shifted interferogram is decomposed into the red, green and blue constituent colors, thus making three sets of five phase shifted intererograms for three different colors from a single set of white light interferogram. This makes the system less time consuming and have lesser effect due to surrounding environment. Initially 3D phase maps of the bacteria are reconstructed for red, green and blue wavelengths from these interferograms using MATLAB, from these phase maps we determines the refractive index (RI) of the bacteria. Experimental results of 3D shape measurement and RI at multiple wavelengths will be presented. These results might find applications for detection of contaminants in water without using any chemical processing and fluorescent dyes.

Electron tomography of whole cultured cells using novel transmission electron imaging technique.

PubMed

Okumura, Taiga; Shoji, Minami; Hisada, Akiko; Ominami, Yusuke; Ito, Sukehiro; Ushiki, Tatsuo; Nakajima, Masato; Ohshima, Takashi

2018-01-01

Since a three-dimensional (3D) cellular ultrastructure is significant for biological functions, it has been investigated using various electron microscopic techniques. Although transmission electron microscopy (TEM)-based techniques are traditionally used, cells must be embedded in resin and sliced into ultrathin sections in sample preparation processes. Block-face observation using a scanning electron microscope (SEM) has also been recently applied to 3D observation of cellular components, but this is a destructive inspection and does not allow re-examination. Therefore, we developed electron tomography using a transmission electron imaging technique called Plate-TEM. With Plate-TEM, the cells cultured directly on a scintillator plate are inserted into a conventional SEM equipped with a Plate-TEM observation system, and their internal structures are observed by detecting scintillation light produced by electrons passing through the cells. This technology has the following four advantages. First, the cells cultured on the plate can be observed at electron-microscopic resolution since they remain on the plate. Second, both surface and internal information can be obtained simultaneously by using electron- and photo-detectors, respectively, because a Plate-TEM detector is installed in an SEM. Third, the cells on the scintillator plate can also be inspected using light microscopy because the plate has transparent features. Finally, correlative observation with other techniques, such as conventional TEM, is possible after Plate-TEM observation because Plate-TEM is a non-destructive analysis technique. We also designed a sample stage to tilt the samples for tomography with Plate-TEM, by which 3D organization of cellular structures can be visualized as a whole cell. In the present study, Mm2T cells were investigated using our tomography system, resulting in 3D visualization of cell organelles such as mitochondria, lipid droplets, and microvilli. Correlative observations with various imaging techniques were also conducted by successive observations with light microscopy, SEM, Plate-TEM, and conventional TEM. Consequently, the Plate-TEM tomography technique encourages understanding of cellular structures at high resolution, which can contribute to cellular biological research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Light Microscopy Module Imaging Tested and Demonstrated

NASA Technical Reports Server (NTRS)

Gati, Frank

2004-01-01

The Fluids Integrated Rack (FIR), a facility-class payload, and the Light Microscopy Module (LMM), a subrack payload, are integrated research facilities that will fly in the U.S. Laboratory module, Destiny, aboard the International Space Station. Both facilities are being engineered, designed, and developed at the NASA Glenn Research Center by Northrop Grumman Information Technology. The FIR is a modular, multiuser scientific research facility that is one of two racks that make up the Fluids and Combustion Facility (the other being the Combustion Integrated Rack). The FIR has a large volume dedicated for experimental hardware; easily reconfigurable diagnostics, power, and data systems that allow for unique experiment configurations; and customizable software. The FIR will also provide imagers, light sources, power management and control, command and data handling for facility and experiment hardware, and data processing and storage. The first payload in the FIR will be the LMM. The LMM integrated with the FIR is a remotely controllable, automated, on-orbit microscope subrack facility, with key diagnostic capabilities for meeting science requirements--including video microscopy to observe microscopic phenonema and dynamic interactions, interferometry to make thin-film measurements with nanometer resolution, laser tweezers to manipulate micrometer-sized particles, confocal microscopy to provide enhanced three-dimensional visualization of structures, and spectrophotometry to measure the photonic properties of materials. Vibration disturbances were identified early in the LMM development phase as a high risk for contaminating the science microgravity environment. An integrated FIR-LMM test was conducted in Glenn's Acoustics Test Laboratory to assess mechanical sources of vibration and their impact to microscopic imaging. The primary purpose of the test was to characterize the LMM response at the sample location, the x-y stage within the microscope, to vibration emissions from the FIR and LMM support structures.

Contribution of flow cytometry to the diagnosis of gastric lymphomas in endoscopic biopsy specimens.

PubMed

Almasri, N M; Zaer, F S; Iturraspe, J A; Braylan, R C

1997-07-01

Gastric lymphomas seem to have unique clinical, pathologic, and immunophenotypic features that set them apart from nodal lymphomas. Microscopic examination of endoscopic biopsy specimens is the most frequent procedure used to diagnose gastric tumors, but it is very difficult, and sometimes impossible, to recognize lymphomas in endoscopic samples by histologic or even immunohistologic methods. Because most gastric lymphomas are of B-cell origin, we used flow cytometry to assess B-cell clonality in gastric biopsy specimens containing dense lymphocytic infiltrates thought to represent lymphoma. We prepared viable cell suspensions from unfixed specimens obtained from 29 consecutive patients who had a previous microscopic diagnosis of suspicious gastric lymphoid infiltrates. We performed immunophenotypic studies with multicolor flow cytometry, and we assessed clonality by examination of immunoglobulin (Ig) light-chain expression analyzed exclusively on B cells identified by anti-CD20 or CD19 antibodies. The mean number of cells recovered was 1.04 x 10(6), from an average of 5.5 gastric biopsy fragments per patient. In 26 of the 29 patients, the number of cells was adequate for analysis. We detected B-cell monoclonality in 16 cases, including 5 in which the percentage of clonal B cells was less than 5%. Of the 16 cases, only 8 could be diagnosed as lymphomas on morphologic grounds alone; the remaining 8 patients had either suspicious lymphoid infiltrates or chronic gastritis. The three cases with an insufficient number of cells were considered non-neoplastic either on histologic grounds alone or in conjunction with Southern analysis of Ig genes. We conclude that flow cytometric immunophenotypic analysis of freshly prepared cell suspensions obtained from endoscopic biopsy specimens can be used to evaluate gastric lymphocytic infiltrates. Specifically, the analysis of surface Ig light-chain expression on B cells distinguishes between monoclonal (lymphoma) and polyclonal (nonlymphoma) infiltrates. The rapidity, ease, quantitative properties, and sensitivity of this technique make it a supplement to the morphologic assessment of gastric lymphoid infiltrates.

Confocal Fluorescence Microscopy of Mung Beanleaves

NASA Astrophysics Data System (ADS)

Chen, Zhiwei; Liu, Dongwu

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

Hyperlens-array-implemented optical microscopy

NASA Astrophysics Data System (ADS)

Iwanaga, Masanobu

2014-08-01

Limit of resolution of conventional optical microscopes has never reached below 100 nm under visible light illumination. We show that numerically designed high-transmittance hyperlens array (HLA) is implemented in an optical microscope and works in practice for achieving one-shot-recording optical images of in-situ placed objects with sub 50 nm resolution in lateral direction. Direct resolution test employing well-defined nanopatterns proves that the HLA-implemented imaging is super-resolution optical microscopy, which works even under nW/mm2 visible illumination for objects. The HLA implementation makes the resolution of conventional microscopes one-scale higher, leading to the 1/10 illumination wavelength range, that is, mesoscopic range.

Plasma sprayed Fe(76)Nd(16)B(8) permanent magnets

NASA Technical Reports Server (NTRS)

Overfelt, R. A.; Anderson, C. D.; Flanagan, W. F.

1986-01-01

Thin coatings (0.16 mm) and thick coatings (0.50 mm) of Fe(76)Nd(16)B(8) were deposited on stainless-steel substrates by low pressure plasma spraying. Microscopic examination of the coatings in a light microscope revealed excessive porosity, but good bonding to the substrate. Fracture cross sections examined in a scanning electron microscope showed the grains to be equiaxed and approximately 1 micron or less in diameter in the as-sprayed condition. The intrinsic coercivities of the as-sprayed coatings varied from 5.8 to 10.9 kOe. The effects of postspray heat treatments on the intrinsic coercivity are also given.

Proximal tubulopathies associated with monoclonal light chains: the spectrum of clinicopathologic manifestations and molecular pathogenesis.

PubMed

Herrera, Guillermo A

2014-10-01

Lesions associated with monoclonal light and heavy chains display a variety of glomerular, tubular interstitial, and vascular manifestations. While some of the entities are well recognized, including light and heavy chain deposition diseases, AL (light chain) and AH (heavy chain) amyloidosis, and light chain ("myeloma") cast nephropathy, other lesions centered on proximal tubules are much less accurately identified, properly diagnosed, and adequately understood in terms of pathogenesis and molecular mechanisms involved. These proximal tubule-centered lesions are typically associated with monoclonal light chains and have not been reported in patients with circulating monoclonal heavy chains. To determine the incidence of proximal tubulopathies in a series of patients with monoclonal light chain-related renal lesions and characterize them with an emphasis on clinical correlations and elucidation of molecular mechanisms involved in their pathogenesis. A study of 5410 renal biopsies with careful evaluation of light microscopic, immunofluorescence, and electron microscopic findings was conducted to identify these monoclonal light/heavy chain-related lesions. In selected cases, ultrastructural immunolabeling was performed to better illustrate and understand molecular mechanisms involved or to resolve specific diagnostic difficulties. In all, 2.5% of the biopsies were diagnosed as demonstrating renal pathology associated with monoclonal light or heavy chains. Of these, approximately 46% were classified as proximal tubule-centered lesions, also referred to as monoclonal light chain-associated proximal tubulopathies. These proximal tubulopathies were divided into 4 groups defined by characteristic immunomorphologic manifestations associated with specific clinical settings. These are important lesions whose recognition in the different clinical settings is extremely important for patients' clinical management, therapeutic purposes, and prognosis. These entities have been segregated into 4 distinct variants, conceptualized morphologically and clinically. Specific mechanisms involved in their pathogenesis are proposed.

Parallel-multiplexed excitation light-sheet microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Xu, Dongli; Zhou, Weibin; Peng, Leilei

2017-02-01

Laser scanning light-sheet imaging allows fast 3D image of live samples with minimal bleach and photo-toxicity. Existing light-sheet techniques have very limited capability in multi-label imaging. Hyper-spectral imaging is needed to unmix commonly used fluorescent proteins with large spectral overlaps. However, the challenge is how to perform hyper-spectral imaging without sacrificing the image speed, so that dynamic and complex events can be captured live. We report wavelength-encoded structured illumination light sheet imaging (λ-SIM light-sheet), a novel light-sheet technique that is capable of parallel multiplexing in multiple excitation-emission spectral channels. λ-SIM light-sheet captures images of all possible excitation-emission channels in true parallel. It does not require compromising the imaging speed and is capable of distinguish labels by both excitation and emission spectral properties, which facilitates unmixing fluorescent labels with overlapping spectral peaks and will allow more labels being used together. We build a hyper-spectral light-sheet microscope that combined λ-SIM with an extended field of view through Bessel beam illumination. The system has a 250-micron-wide field of view and confocal level resolution. The microscope, equipped with multiple laser lines and an unlimited number of spectral channels, can potentially image up to 6 commonly used fluorescent proteins from blue to red. Results from in vivo imaging of live zebrafish embryos expressing various genetic markers and sensors will be shown. Hyper-spectral images from λ-SIM light-sheet will allow multiplexed and dynamic functional imaging in live tissue and animals.

[Structure of newly formed capillaries of the rabbit cornea (electron microscopic study)].

PubMed

Gurina, O Iu; Karaganov, Ia L

1984-08-01

Owing to a complex application of topical analysis and tracer technique, it is possible to carry out a light optic and electron microscopic investigation of newly formed capillaries growing in the rabbit cornea after its chemical burn. The ultrastructural analysis demonstrates certain polymorphism of morphological organization of endotheliocyte in the newly formed capillaries. There is a rather elevated amount of free ribosomes, mitochondria, microtubules and microfilaments in cytoplasm. The granular endoplasmic reticulum and Golgi complex are hypertrophied. Weibel--Palade bodies appear. Taking into account certain morpho-functional peculiarities of endothelial cells along the course of the growing capillaries, on the 8th day of growth three zone are distinguished: 1--area of nondifferentiated endothelium (apex of the capillary), 2--transitional zone, 3--zone of relatively differentiated endothelium situating in the place where the capillary gets off the parental vessel. According to the zones distinguished, the ways of trans-endothelial transport of molecules are investigated. In formation of the capillary barrier-transport function an important role belongs to polymorphism of the endothelial cells along the course of the growing capillary which is determined by differentiation degree of these cells depending on their participation in permeability.

Automated Image Analysis of Lung Branching Morphogenesis from Microscopic Images of Fetal Rat Explants

PubMed Central

Rodrigues, Pedro L.; Rodrigues, Nuno F.; Duque, Duarte; Granja, Sara; Correia-Pinto, Jorge; Vilaça, João L.

2014-01-01

Background. Regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. This work presents a new methodology to accurately quantify the epithelial, outer contour, and peripheral airway buds of lung explants during cellular development from microscopic images. Methods. The outer contour was defined using an adaptive and multiscale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelium was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds was counted as the skeleton branched ends from a skeletonized image of the lung inner epithelia. Results. The time for lung branching morphometric analysis was reduced in 98% in contrast to the manual method. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Nonsignificant differences were found between the automatic and manual results in all culture days. Conclusions. The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lighting characteristics and allowing a reliable comparison between different researchers. PMID:25250057

Aspects on dental hard tissues in primary teeth from patients with Ehlers-Danlos syndrome.

PubMed

Klingberg, Gunilla; Hagberg, Catharina; Norén, Jörgen G; Nietzsche, Sandor

2009-07-01

Ehlers-Danlos syndrome (EDS) is a rare hereditary condition affecting connective tissues and dental hard tissues. Primary enamel and dentine from EDS patients were expected to differ from those of healthy subjects regarding morphology and chemical composition. Forty-seven exfoliated primary teeth from 25 patients with EDS were investigated. Morphology was studied using a polarized light microscope, scanning electron microscope, and X-ray microanalysis. Comparisons were made with 36 primary teeth from 36 healthy patients. Morphological analysis of enamel in EDS teeth showed a high frequency of postnatally hypomineralized enamel and postnatally located incremental lines, whereas dentine was normal in all patients. Chemical analysis could not reveal any differences between EDS and control patients except for lower content of C and a higher Ca/P ratio in the enamel in the EDS teeth, indicating porous enamel. Regarding dentine, EDS teeth had a lower content of C, and a higher content of Ca, P, and O. Ratios for Ca/C and Ca/O were also higher compared with controls. There are several aberrations of booth enamel and dentine in primary teeth from patients with EDS. These could explain the occurrence of both more dental caries and tooth fractures in patients with EDS.

Light Microscopy Module (LMM)-Emulator

NASA Technical Reports Server (NTRS)

Levine, Howard G.; Smith, Trent M.; Richards, Stephanie E.

2016-01-01

The Light Microscopy Module (LMM) is a microscope facility developed at Glenn Research Center (GRC) that provides researchers with powerful imaging capability onboard the International Space Station (ISS). LMM has the ability to have its hardware recongured on-orbit to accommodate a wide variety of investigations, with the capability of remotely acquiring and downloading digital images across multiple levels of magnication.

Microscopic Pattern of Bone Fractures as an Indicator of Blast Trauma: A Pilot Study.

PubMed

Pechníková, Marketa; Mazzarelli, Debora; Poppa, Pasquale; Gibelli, Daniele; Scossa Baggi, Emilio; Cattaneo, Cristina

2015-09-01

The assessment of fractures is a key issue in forensic anthropology; however, very few studies deal with the features of fractures due to explosion in comparison with other traumatic injuries. This study focuses on fractures resulting from blast trauma and two types of blunt force trauma (manual compression and running over), applied to corpses of pigs; 163 osteons were examined within forty fractures by the transmission light microscopy. Blast lesions showed a higher percentage of fracture lines through the Haversian canal, whereas in other types of trauma, the fractures went across the inner lamellae. Significant differences between samples hit by blast energy and those runover or manually compressed were observed (p<0.05). The frequency of pattern A is significantly higher in exploded bones than in runover and compressed. Microscopic analysis of the fracture line may provide information about the type of trauma, especially for what concerns blast trauma. © 2015 American Academy of Forensic Sciences.

Photon path distribution and optical responses of turbid media: theoretical analysis based on the microscopic Beer-Lambert law.

PubMed

Tsuchiya, Y

2001-08-01

A concise theoretical treatment has been developed to describe the optical responses of a highly scattering inhomogeneous medium using functions of the photon path distribution (PPD). The treatment is based on the microscopic Beer-Lambert law and has been found to yield a complete set of optical responses by time- and frequency-domain measurements. The PPD is defined for possible photons having a total zigzag pathlength of l between the points of light input and detection. Such a distribution is independent of the absorption properties of the medium and can be uniquely determined for the medium under quantification. Therefore, the PPD can be calculated with an imaginary reference medium having the same optical properties as the medium under quantification except for the absence of absorption. One of the advantages of this method is that the optical responses, the total attenuation, the mean pathlength, etc are expressed by functions of the PPD and the absorption distribution.

Transmission electron microscopy analysis of skin lesions from sporotrichosis epidemic in Rio de Janeiro, Brazil.

PubMed

Ferreira, Cassio Porto; Oliveira de Almeida, Ana Cristina; Corte-Real, Suzana

2015-02-01

Transmission electron microscopy can yield useful information in a range of scientific fields; it is capable of imaging at a significantly higher resolution than light microscopes and has been a very useful tool in the identification of morphological changes of the dermis as well as assessment of changes in the extracellular matrix. Our aim is to characterize by electron microscopy the cellular profile of lesions caused by Sporothrix schenckii from the sporotrichosis epidemic in its zoonotic form that occurs in Rio de Janeiro, Brazil. © The American Society of Tropical Medicine and Hygiene.

Multimodal Spectral Imaging of Cells Using a Transmission Diffraction Grating on a Light Microscope

PubMed Central

Isailovic, Dragan; Xu, Yang; Copus, Tyler; Saraswat, Suraj; Nauli, Surya M.

2011-01-01

A multimodal methodology for spectral imaging of cells is presented. The spectral imaging setup uses a transmission diffraction grating on a light microscope to concurrently record spectral images of cells and cellular organelles by fluorescence, darkfield, brightfield, and differential interference contrast (DIC) spectral microscopy. Initially, the setup was applied for fluorescence spectral imaging of yeast and mammalian cells labeled with multiple fluorophores. Fluorescence signals originating from fluorescently labeled biomolecules in cells were collected through triple or single filter cubes, separated by the grating, and imaged using a charge-coupled device (CCD) camera. Cellular components such as nuclei, cytoskeleton, and mitochondria were spatially separated by the fluorescence spectra of the fluorophores present in them, providing detailed multi-colored spectral images of cells. Additionally, the grating-based spectral microscope enabled measurement of scattering and absorption spectra of unlabeled cells and stained tissue sections using darkfield and brightfield or DIC spectral microscopy, respectively. The presented spectral imaging methodology provides a readily affordable approach for multimodal spectral characterization of biological cells and other specimens. PMID:21639978