Guidelines on experimental methods to assess mitochondrial dysfunction in cellular models of neurodegenerative diseases.

PubMed

Connolly, Niamh M C; Theurey, Pierre; Adam-Vizi, Vera; Bazan, Nicolas G; Bernardi, Paolo; Bolaños, Juan P; Culmsee, Carsten; Dawson, Valina L; Deshmukh, Mohanish; Duchen, Michael R; Düssmann, Heiko; Fiskum, Gary; Galindo, Maria F; Hardingham, Giles E; Hardwick, J Marie; Jekabsons, Mika B; Jonas, Elizabeth A; Jordán, Joaquin; Lipton, Stuart A; Manfredi, Giovanni; Mattson, Mark P; McLaughlin, BethAnn; Methner, Axel; Murphy, Anne N; Murphy, Michael P; Nicholls, David G; Polster, Brian M; Pozzan, Tullio; Rizzuto, Rosario; Satrústegui, Jorgina; Slack, Ruth S; Swanson, Raymond A; Swerdlow, Russell H; Will, Yvonne; Ying, Zheng; Joselin, Alvin; Gioran, Anna; Moreira Pinho, Catarina; Watters, Orla; Salvucci, Manuela; Llorente-Folch, Irene; Park, David S; Bano, Daniele; Ankarcrona, Maria; Pizzo, Paola; Prehn, Jochen H M

2018-03-01

Neurodegenerative diseases are a spectrum of chronic, debilitating disorders characterised by the progressive degeneration and death of neurons. Mitochondrial dysfunction has been implicated in most neurodegenerative diseases, but in many instances it is unclear whether such dysfunction is a cause or an effect of the underlying pathology, and whether it represents a viable therapeutic target. It is therefore imperative to utilise and optimise cellular models and experimental techniques appropriate to determine the contribution of mitochondrial dysfunction to neurodegenerative disease phenotypes. In this consensus article, we collate details on and discuss pitfalls of existing experimental approaches to assess mitochondrial function in in vitro cellular models of neurodegenerative diseases, including specific protocols for the measurement of oxygen consumption rate in primary neuron cultures, and single-neuron, time-lapse fluorescence imaging of the mitochondrial membrane potential and mitochondrial NAD(P)H. As part of the Cellular Bioenergetics of Neurodegenerative Diseases (CeBioND) consortium ( www.cebiond.org ), we are performing cross-disease analyses to identify common and distinct molecular mechanisms involved in mitochondrial bioenergetic dysfunction in cellular models of Alzheimer's, Parkinson's, and Huntington's diseases. Here we provide detailed guidelines and protocols as standardised across the five collaborating laboratories of the CeBioND consortium, with additional contributions from other experts in the field.

47 CFR 20.6 - CMRS spectrum aggregation limit.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false CMRS spectrum aggregation limit. 20.6 Section... COMMERCIAL MOBILE SERVICES § 20.6 CMRS spectrum aggregation limit. (a) Spectrum limitation. No licensee in... broadband PCS, cellular, and SMR spectrum regulated as CMRS with significant overlap in any geographic area...

47 CFR 20.6 - CMRS spectrum aggregation limit.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false CMRS spectrum aggregation limit. 20.6 Section... COMMERCIAL MOBILE SERVICES § 20.6 CMRS spectrum aggregation limit. (a) Spectrum limitation. No licensee in... broadband PCS, cellular, and SMR spectrum regulated as CMRS with significant overlap in any geographic area...

High resolution FTIR imaging provides automated discrimination and detection of single malaria parasite infected erythrocytes on glass.

PubMed

Perez-Guaita, David; Andrew, Dean; Heraud, Philip; Beeson, James; Anderson, David; Richards, Jack; Wood, Bayden R

2016-06-23

New highly sensitive tools for malaria diagnostics are urgently needed to enable the detection of infection in asymptomatic carriers and patients with low parasitemia. In pursuit of a highly sensitive diagnostic tool that can identify parasite infections at the single cell level, we have been exploring Fourier transform infrared (FTIR) microscopy using a Focal Plane Array (FPA) imaging detector. Here we report for the first time the application of a new optic configuration developed by Agilent that incorporates 25× condenser and objective Cassegrain optics with a high numerical aperture (NA = 0.81) along with additional high magnification optics within the microscope to provide 0.66 micron pixel resolution (total IR system magnification of 61×) to diagnose malaria parasites at the single cell level on a conventional glass microscope slide. The high quality images clearly resolve the parasite's digestive vacuole demonstrating sub-cellular resolution using this approach. Moreover, we have developed an algorithm that first detects the cells in the infrared image, and secondly extracts the average spectrum. The average spectrum is then run through a model based on Partial Least Squares-Discriminant Analysis (PLS-DA), which diagnoses unequivocally the infected from normal cells. The high quality images, and the fact this measurement can be achieved without a synchrotron source on a conventional glass slide, shows promise as a potential gold standard for malaria detection at the single cell level.

Univariate and multivariate methods for chemical mapping of cervical cancer cells

NASA Astrophysics Data System (ADS)

Duraipandian, Shiyamala; Zheng, Wei; Huang, Zhiwei

2012-01-01

Visualization of cells and subcellular organelles are currently carried out using available microscopy methods such as cryoelectron microscopy, and fluorescence microscopy. These methods require external labeling using fluorescent dyes and extensive sample preparations to access the subcellular structures. However, Raman micro-spectroscopy provides a non-invasive, label-free method for imaging the cells with chemical specificity at sub-micrometer spatial resolutions. The scope of this paper is to image the biochemical/molecular distributions in cells associated with cancerous changes. Raman map data sets were acquired from the human cervical carcinoma cell lines (HeLa) after fixation under 785 nm excitation wavelength. The individual spectrum was recorded by raster-scanning the laser beam over the sample with 1μm step size and 10s exposure time. Images revealing nucleic acids, lipids and proteins (phenylalanine, amide I) were reconstructed using univariate methods. In near future, the small pixel to pixel variations will also be imaged using different multivariate methods (PCA, clustering (HCA, K-means, FCM)) to determine the main cellular constitutions. The hyper-spectral image of cell was reconstructed utilizing the spectral contrast at different pixels of the cell (due to the variation in the biochemical distribution) without using fluorescent dyes. Normal cervical squamous cells will also be imaged in order to differentiate normal and cancer cells of cervix using the biochemical changes in different grades of cancer. Based on the information obtained from the pseudo-color maps, constructed from the hyper-spectral cubes, the primary cellular constituents of normal and cervical cancer cells were identified.

THE SUN’S PHOTOSPHERIC CONVECTION SPECTRUM

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

Hathaway, David H.; Teil, Thibaud; Kitiashvili, Irina

2015-10-01

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory spacecraft. Three different analysis methods are used to separately determine spectral coefficients representing the poloidal flows, the toroidal flows, and the radial flows. The amplitudes of these spectral coefficients are constrained by simulated data analyzed with the same procedures as the HMI data. We find that the total velocity spectrum rises smoothly to a peak at a wavenumber of about 120 (wavelength of about 35 Mm), which is typical of supergranules. The spectrummore » levels off out to wavenumbers of about 400, and then rises again to a peak at a wavenumber of about 3500 (wavelength of about 1200 km), which is typical of granules. The velocity spectrum is dominated by the poloidal flow component (horizontal flows with divergence but no curl) at wavenumbers above 30. The toroidal flow component (horizontal flows with curl but no divergence) dominates at wavenumbers less than 30. The radial flow velocity is only about 3% of the total flow velocity at the lowest wavenumbers, but increases in strength to become about 50% at wavenumbers near 4000. The spectrum compares well with the spectrum of giant cell flows at the lowest wavenumbers and with the spectrum of granulation from a 3D radiative-hydrodynamic simulation at the highest wavenumbers.« less

47 CFR 22.948 - Partitioning and Disaggregation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... partition or disaggregate their spectrum to other qualified entities. (2) Partitioning. During the five year... obtaining disaggregated spectrum may only use such spectrum in that portion of the cellular market encompassed by the original licensee's CGSA and may not use such spectrum to provide service to unserved...

47 CFR 22.948 - Partitioning and Disaggregation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... partition or disaggregate their spectrum to other qualified entities. (2) Partitioning. During the five year... obtaining disaggregated spectrum may only use such spectrum in that portion of the cellular market encompassed by the original licensee's CGSA and may not use such spectrum to provide service to unserved...

47 CFR 22.948 - Partitioning and Disaggregation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... partition or disaggregate their spectrum to other qualified entities. (2) Partitioning. During the five year... obtaining disaggregated spectrum may only use such spectrum in that portion of the cellular market encompassed by the original licensee's CGSA and may not use such spectrum to provide service to unserved...

47 CFR 22.948 - Partitioning and Disaggregation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... partition or disaggregate their spectrum to other qualified entities. (2) Partitioning. During the five year... obtaining disaggregated spectrum may only use such spectrum in that portion of the cellular market encompassed by the original licensee's CGSA and may not use such spectrum to provide service to unserved...

Highly stable red-emitting polymer dots for cellular imaging

NASA Astrophysics Data System (ADS)

Chelora, Jipsa; Zhang, Jinfeng; Chen, Rui; Thachoth Chandran, Hrisheekesh; Lee, Chun-Sing

2017-07-01

Polymer dots (Pdots) have emerged as a new type of fluorescent probe material for biomedical applications and have attracted great interest due to their excellent optical properties and biocompatability. In this work, we report on a red-emitting P3HT Pdot fluorescent probe for intracellular bioimaging. The as-prepared Pdot fluorescent probe exhibits good stability and has a large Stokes shift (121 nm) compared to molecules in tetrahydrofuran (THF). Furthermore, the probe shows low cytotoxicity, broad absorption spectrum, resistance against photodegradation, and good water dispersibility. These advantageous characteristics make P3HT Pdots a promising fluorescent probe material for bioimaging.

Highly stable red-emitting polymer dots for cellular imaging.

PubMed

Chelora, Jipsa; Zhang, Jinfeng; Chen, Rui; Chandran, Hrisheekesh Thachoth; Lee, Chun-Sing

2017-07-14

Polymer dots (Pdots) have emerged as a new type of fluorescent probe material for biomedical applications and have attracted great interest due to their excellent optical properties and biocompatability. In this work, we report on a red-emitting P 3 HT Pdot fluorescent probe for intracellular bioimaging. The as-prepared Pdot fluorescent probe exhibits good stability and has a large Stokes shift (121 nm) compared to molecules in tetrahydrofuran (THF). Furthermore, the probe shows low cytotoxicity, broad absorption spectrum, resistance against photodegradation, and good water dispersibility. These advantageous characteristics make P 3 HT Pdots a promising fluorescent probe material for bioimaging.

Analytical formulation of cellular automata rules using data models

NASA Astrophysics Data System (ADS)

Jaenisch, Holger M.; Handley, James W.

2009-05-01

We present a unique method for converting traditional cellular automata (CA) rules into analytical function form. CA rules have been successfully used for morphological image processing and volumetric shape recognition and classification. Further, the use of CA rules as analog models to the physical and biological sciences can be significantly extended if analytical (as opposed to discrete) models could be formulated. We show that such transformations are possible. We use as our example John Horton Conway's famous "Game of Life" rule set. We show that using Data Modeling, we are able to derive both polynomial and bi-spectrum models of the IF-THEN rules that yield equivalent results. Further, we demonstrate that the "Game of Life" rule set can be modeled using the multi-fluxion, yielding a closed form nth order derivative and integral. All of the demonstrated analytical forms of the CA rule are general and applicable to real-time use.

Visualizing Cell Architecture and Molecular Location Using Soft X-Ray Tomography and Correlated Cryo-Light Microscopy

PubMed Central

McDermott, Gerry; Le Gros, Mark A.; Larabell, Carolyn A.

2012-01-01

Living cells are structured to create a range of microenvironments that support specific chemical reactions and processes. Understanding how cells function therefore requires detailed knowledge of both the subcellular architecture and the location of specific molecules within this framework. Here we review the development of two correlated cellular imaging techniques that fulfill this need. Cells are first imaged using cryogenic fluorescence microscopy to determine the location of molecules of interest that have been labeled with fluorescent tags. The same specimen is then imaged using soft X-ray tomography to generate a high-contrast, 3D reconstruction of the cells. Data from the two modalities are then combined to produce a composite, information-rich view of the cell. This correlated imaging approach can be applied across the spectrum of problems encountered in cell biology, from basic research to biotechnological and biomedical applications such as the optimization of biofuels and the development of new pharmaceuticals. PMID:22242730

MicroRaman Spectroscopy and Raman Imaging of Basal Cell Carcinoma

NASA Astrophysics Data System (ADS)

Short, M. A.; Zeng, H.; Lui, H.

2005-03-01

We have measured the Raman spectra of normal and cancerous skin tissues using a confocal microRaman spectrograph with a sub-micron spatial resolution. We found that the Raman spectrum of a cell nucleolus is different from the spectra measured outside the nucleolus and considerably different from those measured outside the nucleus. In addition, we found significant spectroscopic differences between normal and cancer-bearing sites in the dermis region. In order to utilize these differences for non-invasive skin cancer diagnosis, we have developed a Raman imaging system that clearly demonstrates the structure, location and distribution of cells in unstained skin biopsy samples. Our method is expected to be useful for the detection and characterization of skin cancer based on the known distinct cellular differences between normal and malignant skin.

Rapid acquisition of mean Raman spectra of eukaryotic cells for a robust single cell classification.

PubMed

Schie, Iwan W; Kiselev, Roman; Krafft, Christoph; Popp, Jürgen

2016-11-14

Raman spectroscopy has previously been used to identify eukaryotic and prokaryotic cells. While prokaryotic cells are small in size and can be assessed by a single Raman spectrum, the larger size of eukaryotic cells and their complex organization requires the acquisition of multiple Raman spectra to properly characterize them. A Raman spectrum from a diffraction-limited spot at an arbitrary location within a cell results in spectral variations that affect classification approaches. To probe whole cells with Raman imaging at high spatial resolution is time consuming, because a large number of Raman spectra need to be collected, resulting in low cell throughput and impairing statistical analysis due to low cell numbers. Here we propose a method to overcome the effects of cellular heterogeneity by acquiring integrated Raman spectra covering a large portion of a cell. The acquired spectrum represents the mean macromolecular composition of a cell with an exposure time that is comparable to acquisition of a single Raman spectrum. Data sets were collected from T lymphocyte Jurkat cells, and pancreatic cell lines Capan1 and MiaPaca2. Cell classification by support vector machines was compared for single spectra, spectra of images and integrated Raman spectra of cells. The integrated approach provides better and more stable prediction for individual cells, and in the current implementation, the mean macromolecular information of a cell can be acquired faster than with the acquisition of individual spectra from a comparable region. It is expected that this approach will have a major impact on the implementation of Raman based cell classification.

A spectrum fractal feature classification algorithm for agriculture crops with hyper spectrum image

NASA Astrophysics Data System (ADS)

Su, Junying

2011-11-01

A fractal dimension feature analysis method in spectrum domain for hyper spectrum image is proposed for agriculture crops classification. Firstly, a fractal dimension calculation algorithm in spectrum domain is presented together with the fast fractal dimension value calculation algorithm using the step measurement method. Secondly, the hyper spectrum image classification algorithm and flowchart is presented based on fractal dimension feature analysis in spectrum domain. Finally, the experiment result of the agricultural crops classification with FCL1 hyper spectrum image set with the proposed method and SAM (spectral angle mapper). The experiment results show it can obtain better classification result than the traditional SAM feature analysis which can fulfill use the spectrum information of hyper spectrum image to realize precision agricultural crops classification.

Fluorescence lifetime imaging microscopy using near-infrared contrast agents.

PubMed

Nothdurft, R; Sarder, P; Bloch, S; Culver, J; Achilefu, S

2012-08-01

Although single-photon fluorescence lifetime imaging microscopy (FLIM) is widely used to image molecular processes using a wide range of excitation wavelengths, the captured emission of this technique is confined to the visible spectrum. Here, we explore the feasibility of utilizing near-infrared (NIR) fluorescent molecular probes with emission >700 nm for FLIM of live cells. The confocal microscope is equipped with a 785 nm laser diode, a red-enhanced photomultiplier tube, and a time-correlated single photon counting card. We demonstrate that our system reports the lifetime distributions of NIR fluorescent dyes, cypate and DTTCI, in cells. In cells labelled separately or jointly with these dyes, NIR FLIM successfully distinguishes their lifetimes, providing a method to sort different cell populations. In addition, lifetime distributions of cells co-incubated with these dyes allow estimate of the dyes' relative concentrations in complex cellular microenvironments. With the heightened interest in fluorescence lifetime-based small animal imaging using NIR fluorophores, this technique further serves as a bridge between in vitro spectroscopic characterization of new fluorophore lifetimes and in vivo tissue imaging. © 2012 The Author Journal of Microscopy © 2012 Royal Microscopical Society.

Fluorescence Lifetime Imaging Microscopy Using Near-Infrared Contrast Agents

PubMed Central

Nothdurft, Ralph; Sarder, Pinaki; Bloch, Sharon; Culver, Joseph; Achilefu, Samuel

2013-01-01

Although single-photon fluorescence lifetime imaging microscopy (FLIM) is widely used to image molecular processes using a wide range of excitation wavelengths, the captured emission of this technique is confined to the visible spectrum. Here, we explore the feasibility of utilizing near-infrared (NIR) fluorescent molecular probes with emission >700 nm for FLIM of live cells. The confocal microscope is equipped with a 785 nm laser diode, a red-enhanced photomultiplier tube, and a time-correlated single photon counting card. We demonstrate that our system reports the lifetime distributions of NIR fluorescent dyes, cypate and DTTCI, in cells. In cells labeled separately or jointly with these dyes, NIR FLIM successfully distinguishes their lifetimes, providing a method to sort different cell populations. In addition, lifetime distributions of cells co-incubated with these dyes allow estimate of the dyes’ relative concentrations in complex cellular microenvironments. With the heightened interest in fluorescence lifetime-based small animal imaging using NIR fluorophores, this technique further serves as a bridge between in vitro spectroscopic characterization of new fluorophore lifetimes and in vivo tissue imaging. PMID:22788550

Effects of antibacterial mineral leachates on the cellular ultrastructure, morphology, and membrane integrity of Escherichia coli and methicillin-resistant Staphylococcus aureus

PubMed Central

2010-01-01

Background We have previously identified two mineral mixtures, CB07 and BY07, and their respective aqueous leachates that exhibit in vitro antibacterial activity against a broad spectrum of pathogens. The present study assesses cellular ultrastructure and membrane integrity of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli after exposure to CB07 and BY07 aqueous leachates. Methods We used scanning and transmission electron microscopy to evaluate E. coli and MRSA ultrastructure and morphology following exposure to antibacterial leachates. Additionally, we employed Baclight LIVE/DEAD staining and flow cytometry to investigate the cellular membrane as a possible target for antibacterial activity. Results Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging of E. coli and MRSA revealed intact cells following exposure to antibacterial mineral leachates. TEM images of MRSA showed disruption of the cytoplasmic contents, distorted cell shape, irregular membranes, and distorted septa of dividing cells. TEM images of E. coli exposed to leachates exhibited different patterns of cytoplasmic condensation with respect to the controls and no apparent change in cell envelope structure. Although bactericidal activity of the leachates occurs more rapidly in E. coli than in MRSA, LIVE/DEAD staining demonstrated that the membrane of E. coli remains intact, while the MRSA membrane is permeabilized following exposure to the leachates. Conclusions These data suggest that the leachate antibacterial mechanism of action differs for Gram-positive and Gram-negative organisms. Upon antibacterial mineral leachate exposure, structural integrity is retained, however, compromised membrane integrity accounts for bactericidal activity in Gram-positive, but not in Gram-negative cells. PMID:20846374

Investigation of phosphoserine and cytidine 5'-phosphate by heteronuclear two-dimensional spectroscopy: samples with strong proton coupling

NASA Astrophysics Data System (ADS)

Bolton, Philip H.

Heteronuclear two-dimensional magnetic resonance is a novel method for investigating the conformations of cellular phosphates. The two-dimensional proton spectra are detected indirectly via the phosphorus-31 nucleus and thus allow determination of proton chemical shifts and coupling constants in situations in which the normal proton spectrum is obscured. Previous investigations of cellular phosphates with relatively simple spin systems have shown that the two-dimensional proton spectrum can be readily related to the normal proton spectrum by subspectral analysis. The normal proton spectrum can be decomposed into two subspectra, one for each polarization of the phosphorus-31 nucleus. The two-dimensional spectrum arises from the difference between the subspectra, and the normal proton spectrum is the sum. This allows simulation of the two-dimensional spectra and hence determination of the proton chemical shifts and coupling constants. Many cellular phosphates of interest, such as 5'-nucleotides and phosphoserine, contain three protons coupled to the phosphorus which are strongly coupled to one another. These samples are amenable to the two-dimensional method and the straightforward subspectral analysis is preserved when a 90° pulse is applied to the protons in the magnetization transfer step. The two-dimensional proton spectra of the samples investigated here have higher resolution than the normal proton spectra, revealing spectral features not readily apparent in the normal proton spectra.

Broadband hyperspectral coherent anti-Stokes Raman scattering microscopy for stain-free histological imaging with principal component analysis

NASA Astrophysics Data System (ADS)

Xu, Jingjiang; Guo, Baoshan; Wong, Kenneth K. Y.; Tsia, Kevin K.

2014-02-01

Routine procedures in standard histopathology involve laborious steps of tissue processing and staining for final examination. New techniques which can bypass these procedures and thus minimize the tissue handling error would be of great clinical value. Coherent anti-Stokes Raman scattering (CARS) microscopy is an attractive tool for label-free biochemical-specific characterization of biological specimen. However, a vast majority of prior works on CARS (or stimulated Raman scattering (SRS)) bioimaging restricted analyses on a narrowband or well-distinctive Raman spectral signatures. Although hyperspectral SRS/CARS imaging has recently emerged as a better solution to access wider-band spectral information in the image, studies mostly focused on a limited spectral range, e.g. CH-stretching vibration of lipids, or non-biological samples. Hyperspectral image information in the congested fingerprint spectrum generally remains untapped for biological samples. In this regard, we further explore ultrabroadband hyperspectral multiplex (HM-CARS) to perform chemoselective histological imaging with the goal of exploring its utility in stain-free clinical histopathology. Using the supercontinuum Stokes, our system can access the CARS spectral window as wide as >2000cm-1. In order to unravel the congested CARS spectra particularly in the fingerprint region, we first employ a spectral phase-retrieval algorithm based on Kramers-Kronig (KK) transform to minimize the non-resonant background in the CARS spectrum. We then apply principal component analysis (PCA) to identify and map the spatial distribution of different biochemical components in the tissues. We demonstrate chemoselective HM-CARS imaging of a colon tissue section which displays the key cellular structures that correspond well with standard stained-tissue observation.

Method to Detect the Cellular Source of Over-Activated NADPH Oxidases Using NAD(P)H Fluorescence Lifetime Imaging.

PubMed

Bremer, Daniel; Leben, Ruth; Mothes, Ronja; Radbruch, Helena; Niesner, Raluca

2017-04-03

Fluorescence-lifetime imaging microscopy (FLIM) is a technique to generate images, in which the contrast is obtained by the excited-state lifetime of fluorescent molecules instead of their intensity and emission spectrum. The ubiquitous coenzymes NADH and NADPH, hereafter NAD(P)H, in cells show a short fluorescence lifetime ≈400 psec in the free-state and a longer fluorescence lifetime when bound to enzymes. The fluorescence lifetime of NAD(P)H in this state depends on the binding-site on the specific enzyme. In the case of NADPH bound to members of the NADPH oxidases family we measured a fluorescence lifetime of 3650 psec as compared to enzymes typically active in cells, in which case fluorescence lifetimes of ∼2000 psec are measured. Here we present a robust protocol based on NAD(P)H fluorescence lifetime imaging in isolated cells to distinguish between normally active enzymes and NADPH oxidases, mainly responsible for oxidative stress. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Imaging the Directed Transport of Single Engineered RNA Transcripts in Real-Time Using Ratiometric Bimolecular Beacons

PubMed Central

Zhang, Xuemei; Zajac, Allison L.; Huang, Lingyan; Behlke, Mark A.; Tsourkas, Andrew

2014-01-01

The relationship between RNA expression and cell function can often be difficult to decipher due to the presence of both temporal and sub-cellular processing of RNA. These intricacies of RNA regulation can often be overlooked when only acquiring global measurements of RNA expression. This has led to development of several tools that allow for the real-time imaging of individual engineered RNA transcripts in living cells. Here, we describe a new technique that utilizes an oligonucleotide-based probe, ratiometric bimolecular beacon (RBMB), to image RNA transcripts that were engineered to contain 96-tandem repeats of the RBMB target sequence in the 3′-untranslated region. Binding of RBMBs to the target RNA resulted in discrete bright fluorescent spots, representing individual transcripts, that could be imaged in real-time. Since RBMBs are a synthetic probe, the use of photostable, bright, and red-shifted fluorophores led to a high signal-to-background. RNA motion was readily characterized by both mean squared displacement and moment scaling spectrum analyses. These analyses revealed clear examples of directed, Brownian, and subdiffusive movements. PMID:24454933

Challenges in structural approaches to cell modeling

PubMed Central

Im, Wonpil; Liang, Jie; Olson, Arthur; Zhou, Huan-Xiang; Vajda, Sandor; Vakser, Ilya A.

2016-01-01

Computational modeling is essential for structural characterization of biomolecular mechanisms across the broad spectrum of scales. Adequate understanding of biomolecular mechanisms inherently involves our ability to model them. Structural modeling of individual biomolecules and their interactions has been rapidly progressing. However, in terms of the broader picture, the focus is shifting toward larger systems, up to the level of a cell. Such modeling involves a more dynamic and realistic representation of the interactomes in vivo, in a crowded cellular environment, as well as membranes and membrane proteins, and other cellular components. Structural modeling of a cell complements computational approaches to cellular mechanisms based on differential equations, graph models, and other techniques to model biological networks, imaging data, etc. Structural modeling along with other computational and experimental approaches will provide a fundamental understanding of life at the molecular level and lead to important applications to biology and medicine. A cross section of diverse approaches presented in this review illustrates the developing shift from the structural modeling of individual molecules to that of cell biology. Studies in several related areas are covered: biological networks; automated construction of three-dimensional cell models using experimental data; modeling of protein complexes; prediction of non-specific and transient protein interactions; thermodynamic and kinetic effects of crowding; cellular membrane modeling; and modeling of chromosomes. The review presents an expert opinion on the current state-of-the-art in these various aspects of structural modeling in cellular biology, and the prospects of future developments in this emerging field. PMID:27255863

Detection of latent fingerprints by ultraviolet spectral imaging

NASA Astrophysics Data System (ADS)

Huang, Wei; Xu, Xiaojing; Wang, Guiqiang

2013-12-01

Spectral imaging technology research is becoming more popular in the field of forensic science. Ultraviolet spectral imaging technology is an especial part of the full spectrum of imaging technology. This paper finished the experiment contents of the ultraviolet spectrum imaging method and image acquisition system based on ultraviolet spectral imaging technology. Ultraviolet spectral imaging experiments explores a wide variety of ultraviolet reflectance spectra of the object material curve and its ultraviolet spectrum of imaging modalities, can not only gives a reference for choosing ultraviolet wavelength to show the object surface potential traces of substances, but also gives important data for the ultraviolet spectrum of imaging technology development.

A novel fiber laser development for photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Yavas, Seydi; Aytac-Kipergil, Esra; Arabul, Mustafa U.; Erkol, Hakan; Akcaalan, Onder; Eldeniz, Y. Burak; Ilday, F. Omer; Unlu, Mehmet B.

2013-03-01

Photoacoustic microscopy, as an imaging modality, has shown promising results in imaging angiogenesis and cutaneous malignancies like melanoma, revealing systemic diseases including diabetes, hypertension, tracing drug efficiency and assessment of therapy, monitoring healing processes such as wound cicatrization, brain imaging and mapping. Clinically, photoacoustic microscopy is emerging as a capable diagnostic tool. Parameters of lasers used in photoacoustic microscopy, particularly, pulse duration, energy, pulse repetition frequency, and pulse-to-pulse stability affect signal amplitude and quality, data acquisition speed and indirectly, spatial resolution. Lasers used in photoacoustic microscopy are typically Q-switched lasers, low-power laser diodes, and recently, fiber lasers. Significantly, the key parameters cannot be adjusted independently of each other, whereas microvasculature and cellular imaging, e.g., have different requirements. Here, we report an integrated fiber laser system producing nanosecond pulses, covering the spectrum from 600 nm to 1100 nm, developed specifically for photoacoustic excitation. The system comprises of Yb-doped fiber oscillator and amplifier, an acousto-optic modulator and a photonic-crystal fiber to generate supercontinuum. Complete control over the pulse train, including generation of non-uniform pulse trains, is achieved via the AOM through custom-developed field-programmable gate-array electronics. The system is unique in that all the important parameters are adjustable: pulse duration in the range of 1-3 ns, pulse energy up to 10 μJ, repetition rate from 50 kHz to 3 MHz. Different photocoustic imaging probes can be excited with the ultrabroad spectrum. The entire system is fiber-integrated; guided-beam-propagation rendersit misalignment free and largely immune to mechanical perturbations. The laser is robust, low-cost and built using readily available components.

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

PubMed

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

2015-01-01

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

Altered proliferation and networks in neural cells derived from idiopathic autistic individuals.

PubMed

Marchetto, Maria C; Belinson, Haim; Tian, Yuan; Freitas, Beatriz C; Fu, Chen; Vadodaria, Krishna; Beltrao-Braga, Patricia; Trujillo, Cleber A; Mendes, Ana P D; Padmanabhan, Krishnan; Nunez, Yanelli; Ou, Jing; Ghosh, Himanish; Wright, Rebecca; Brennand, Kristen; Pierce, Karen; Eichenfield, Lawrence; Pramparo, Tiziano; Eyler, Lisa; Barnes, Cynthia C; Courchesne, Eric; Geschwind, Daniel H; Gage, Fred H; Wynshaw-Boris, Anthony; Muotri, Alysson R

2017-06-01

Autism spectrum disorders (ASD) are common, complex and heterogeneous neurodevelopmental disorders. Cellular and molecular mechanisms responsible for ASD pathogenesis have been proposed based on genetic studies, brain pathology and imaging, but a major impediment to testing ASD hypotheses is the lack of human cell models. Here, we reprogrammed fibroblasts to generate induced pluripotent stem cells, neural progenitor cells (NPCs) and neurons from ASD individuals with early brain overgrowth and non-ASD controls with normal brain size. ASD-derived NPCs display increased cell proliferation because of dysregulation of a β-catenin/BRN2 transcriptional cascade. ASD-derived neurons display abnormal neurogenesis and reduced synaptogenesis leading to functional defects in neuronal networks. Interestingly, defects in neuronal networks could be rescued by insulin growth factor 1 (IGF-1), a drug that is currently in clinical trials for ASD. This work demonstrates that selection of ASD subjects based on endophenotypes unraveled biologically relevant pathway disruption and revealed a potential cellular mechanism for the therapeutic effect of IGF-1.

Unguioblastoma and unguioblastic fibroma--an expanded spectrum of onychomatricoma.

PubMed

Ko, Christine J; Shi, Linda; Barr, Ronald J; Mölne, Lena; Ternesten-Bratel, Annika; Headington, John T

2004-04-01

Onychomatricoma is a rare tumor that appears to originate from cells of the nail matrix. Three cases of onychomatricoma that met Perrin et al.'s1 histologic criteria of onychomatricoma are described. However, using a single term to classify all three tumors ignores the apparent microscopic differences that exist among them. To demonstrate better the spectrum of so-called onychomatricoma and properly acknowledge the noticeable disparity among our cases, a series of terms is proposed. This terminology is based on the histologic spectrum of epithelial-stromal ratio of stromal cellularity and of extent nuclear pleomorphism. Use of such criteria has a precedent in the classification of follicular and odontogenic fibroepithelial neoplasms. This new nomenclature includes "unguioblastoma" for tumors with a predominant epithelial component and "unguioblastic fibroma" for tumors where a cellular stroma is more prominent and characteristic. The term "atypical unguioblastic fibroma" is used to describe a third rare neoplasm, in which the cellular stroma shows nuclear pleomorphism and atypia with an increase of mitotic activity.

A most spectrum-efficient duplexing system: CDD

NASA Astrophysics Data System (ADS)

Lee, William C. Y.

2001-10-01

The game to play in wireless communications when it comes to increasing spectrum efficiency is to eliminate interference. Currently, all cellular systems use FDD (Frequency Division Duplexing) in an attempt to eliminate the interference from the adjacent cells. Through the use of many technologies only one type of interference remains and that is the adjacent base-tohome mobile interference. TDD (Time Division Duplexing) has not been used for mobile cellular systems, not only because of the adjacent base-to-home mobile interference, but also because of the additional adjacent base-to-home base interference, and adjacent mobile-to-home mobile interference. Therefore, TDD can only be used for small, confined area systems. CDD (Code Division Duplexing) can eliminate all three kinds of interference; the adjacent base-to-home mobile, the adjacent baseto-home base, and the adjacent mobile- to- home in cellular systems. Eliminating each of these interferences makes CDD the most spectrum efficient duplexing system. This talk will elaborate on a set of smart codes, which will make an efficient CDD system a reality.

Cellular Imaging With MRI.

PubMed

Makela, Ashley V; Murrell, Donna H; Parkins, Katie M; Kara, Jenna; Gaudet, Jeffrey M; Foster, Paula J

2016-10-01

Cellular magnetic resonance imaging (MRI) is an evolving field of imaging with strong translational and research potential. The ability to detect, track, and quantify cells in vivo and over time allows for studying cellular events related to disease processes and may be used as a biomarker for decisions about treatments and for monitoring responses to treatments. In this review, we discuss methods for labeling cells, various applications for cellular MRI, the existing limitations, strategies to address these shortcomings, and clinical cellular MRI.

Self-organized perturbations enhance class IV behavior and 1/f power spectrum in elementary cellular automata.

PubMed

Nakajima, Kohei; Haruna, Taichi

2011-09-01

In this paper, we propose a new class of cellular automata based on the modification of its state space. It is introduced to model a computation which is exposed to an environment. We formalized the computation as extension and projection processes of its state space and resulting misidentifications of the state. This is motivated to embed the role of an environment into the system itself, which naturally induces self-organized internal perturbations rather than the usual external perturbations. Implementing this structure into the elementary cellular automata, we characterized its effect by means of input entropy and power spectral analysis. As a result, the cellular automata with this structure showed robust class IV behavior and a 1/f power spectrum in a wide range of rule space comparative to the notion of the edge of chaos. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Advances in molecular labeling, high throughput imaging and machine intelligence portend powerful functional cellular biochemistry tools.

PubMed

Price, Jeffrey H; Goodacre, Angela; Hahn, Klaus; Hodgson, Louis; Hunter, Edward A; Krajewski, Stanislaw; Murphy, Robert F; Rabinovich, Andrew; Reed, John C; Heynen, Susanne

2002-01-01

Cellular behavior is complex. Successfully understanding systems at ever-increasing complexity is fundamental to advances in modern science and unraveling the functional details of cellular behavior is no exception. We present a collection of prospectives to provide a glimpse of the techniques that will aid in collecting, managing and utilizing information on complex cellular processes via molecular imaging tools. These include: 1) visualizing intracellular protein activity with fluorescent markers, 2) high throughput (and automated) imaging of multilabeled cells in statistically significant numbers, and 3) machine intelligence to analyze subcellular image localization and pattern. Although not addressed here, the importance of combining cell-image-based information with detailed molecular structure and ligand-receptor binding models cannot be overlooked. Advanced molecular imaging techniques have the potential to impact cellular diagnostics for cancer screening, clinical correlations of tissue molecular patterns for cancer biology, and cellular molecular interactions for accelerating drug discovery. The goal of finally understanding all cellular components and behaviors will be achieved by advances in both instrumentation engineering (software and hardware) and molecular biochemistry. Copyright 2002 Wiley-Liss, Inc.

Using cellular automata to generate image representation for biological sequences.

PubMed

Xiao, X; Shao, S; Ding, Y; Huang, Z; Chen, X; Chou, K-C

2005-02-01

A novel approach to visualize biological sequences is developed based on cellular automata (Wolfram, S. Nature 1984, 311, 419-424), a set of discrete dynamical systems in which space and time are discrete. By transforming the symbolic sequence codes into the digital codes, and using some optimal space-time evolvement rules of cellular automata, a biological sequence can be represented by a unique image, the so-called cellular automata image. Many important features, which are originally hidden in a long and complicated biological sequence, can be clearly revealed thru its cellular automata image. With biological sequences entering into databanks rapidly increasing in the post-genomic era, it is anticipated that the cellular automata image will become a very useful vehicle for investigation into their key features, identification of their function, as well as revelation of their "fingerprint". It is anticipated that by using the concept of the pseudo amino acid composition (Chou, K.C. Proteins: Structure, Function, and Genetics, 2001, 43, 246-255), the cellular automata image approach can also be used to improve the quality of predicting protein attributes, such as structural class and subcellular location.

Mechanistic insights of the Min oscillator via cell-free reconstitution and imaging

NASA Astrophysics Data System (ADS)

Mizuuchi, Kiyoshi; Vecchiarelli, Anthony G.

2018-05-01

The MinD and MinE proteins of Escherichia coli self-organize into a standing-wave oscillator on the membrane to help align division at mid-cell. When unleashed from cellular confines, MinD and MinE form a spectrum of patterns on artificial bilayers—static amoebas, traveling waves, traveling mushrooms, and bursts with standing-wave dynamics. We recently focused our cell-free studies on bursts because their dynamics recapitulate many features of Min oscillation observed in vivo. The data unveiled a patterning mechanism largely governed by MinE regulation of MinD interaction with membrane. We proposed that the MinD to MinE ratio on the membrane acts as a toggle switch between MinE-stimulated recruitment and release of MinD from the membrane. In this review, we summarize cell-free data on the Min system and expand upon a molecular mechanism that provides a biochemical explanation as to how these two ‘simple’ proteins can form the remarkable spectrum of patterns.

X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

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

Stead, A.D.; Ford, T.W.; Page, A.M.

1997-04-01

Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called {open_quotes}water window{close_quotes} area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examinedmore » the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition.« less

iScreen: Image-Based High-Content RNAi Screening Analysis Tools.

PubMed

Zhong, Rui; Dong, Xiaonan; Levine, Beth; Xie, Yang; Xiao, Guanghua

2015-09-01

High-throughput RNA interference (RNAi) screening has opened up a path to investigating functional genomics in a genome-wide pattern. However, such studies are often restricted to assays that have a single readout format. Recently, advanced image technologies have been coupled with high-throughput RNAi screening to develop high-content screening, in which one or more cell image(s), instead of a single readout, were generated from each well. This image-based high-content screening technology has led to genome-wide functional annotation in a wider spectrum of biological research studies, as well as in drug and target discovery, so that complex cellular phenotypes can be measured in a multiparametric format. Despite these advances, data analysis and visualization tools are still largely lacking for these types of experiments. Therefore, we developed iScreen (image-Based High-content RNAi Screening Analysis Tool), an R package for the statistical modeling and visualization of image-based high-content RNAi screening. Two case studies were used to demonstrate the capability and efficiency of the iScreen package. iScreen is available for download on CRAN (http://cran.cnr.berkeley.edu/web/packages/iScreen/index.html). The user manual is also available as a supplementary document. © 2014 Society for Laboratory Automation and Screening.

Unsupervised malaria parasite detection based on phase spectrum.

PubMed

Fang, Yuming; Xiong, Wei; Lin, Weisi; Chen, Zhenzhong

2011-01-01

In this paper, we propose a novel method for malaria parasite detection based on phase spectrum. The method first obtains the amplitude spectrum and phase spectrum for blood smear images through Quaternion Fourier Transform (QFT). Then it gets the reconstructed image based on Inverse Quaternion Fourier transform (IQFT) on a constant amplitude spectrum and the original phase spectrum. The malaria parasite areas can be detected easily from the reconstructed blood smear images. Extensive experiments have demonstrated the effectiveness of this novel method.

Challenges in structural approaches to cell modeling.

PubMed

Im, Wonpil; Liang, Jie; Olson, Arthur; Zhou, Huan-Xiang; Vajda, Sandor; Vakser, Ilya A

2016-07-31

Computational modeling is essential for structural characterization of biomolecular mechanisms across the broad spectrum of scales. Adequate understanding of biomolecular mechanisms inherently involves our ability to model them. Structural modeling of individual biomolecules and their interactions has been rapidly progressing. However, in terms of the broader picture, the focus is shifting toward larger systems, up to the level of a cell. Such modeling involves a more dynamic and realistic representation of the interactomes in vivo, in a crowded cellular environment, as well as membranes and membrane proteins, and other cellular components. Structural modeling of a cell complements computational approaches to cellular mechanisms based on differential equations, graph models, and other techniques to model biological networks, imaging data, etc. Structural modeling along with other computational and experimental approaches will provide a fundamental understanding of life at the molecular level and lead to important applications to biology and medicine. A cross section of diverse approaches presented in this review illustrates the developing shift from the structural modeling of individual molecules to that of cell biology. Studies in several related areas are covered: biological networks; automated construction of three-dimensional cell models using experimental data; modeling of protein complexes; prediction of non-specific and transient protein interactions; thermodynamic and kinetic effects of crowding; cellular membrane modeling; and modeling of chromosomes. The review presents an expert opinion on the current state-of-the-art in these various aspects of structural modeling in cellular biology, and the prospects of future developments in this emerging field. Copyright © 2016 Elsevier Ltd. All rights reserved.

Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging.

PubMed

Jauniaux, Eric; Collins, Sally; Burton, Graham J

2018-01-01

Placenta accreta spectrum is a complex obstetric complication associated with high maternal morbidity. It is a relatively new disorder of placentation, and is the consequence of damage to the endometrium-myometrial interface of the uterine wall. When first described 80 years ago, it mainly occurred after manual removal of the placenta, uterine curettage, or endometritis. Superficial damage leads primarily to an abnormally adherent placenta, and is diagnosed as the complete or partial absence of the decidua on histology. Today, the main cause of placenta accreta spectrum is uterine surgery and, in particular, uterine scar secondary to cesarean delivery. In the absence of endometrial reepithelialization of the scar area the trophoblast and villous tissue can invade deeply within the myometrium, including its circulation, and reach the surrounding pelvic organs. The cellular changes in the trophoblast observed in placenta accreta spectrum are probably secondary to the unusual myometrial environment in which it develops, and not a primary defect of trophoblast biology leading to excessive invasion of the myometrium. Placenta accreta spectrum was separated by pathologists into 3 categories: placenta creta when the villi simply adhere to the myometrium, placenta increta when the villi invade the myometrium, and placenta percreta where the villi invade the full thickness of the myometrium. Several prenatal ultrasound signs of placenta accreta spectrum were reported over the last 35 years, principally the disappearance of the normal uteroplacental interface (clear zone), extreme thinning of the underlying myometrium, and vascular changes within the placenta (lacunae) and placental bed (hypervascularity). The pathophysiological basis of these signs is due to permanent damage of the uterine wall as far as the serosa, with placental tissue reaching the deep uterine circulation. Adherent and invasive placentation may coexist in the same placental bed and evolve with advancing gestation. This may explain why no single, or set combination of, ultrasound sign(s) was found to be specific for the depth of abnormal placentation, and accurate for the differential diagnosis between adherent and invasive placentation. Correlation of pathological and clinical findings with prenatal imaging is essential to improve screening, diagnosis, and management of placenta accreta spectrum, and standardized protocols need to be developed. Copyright © 2017 Elsevier Inc. All rights reserved.

[The age-related changes in hemolymph cellular composition and in the spectrum of cytomorphological traits of hemocyte genetic damages in snail Lymnaea stagnalis].

PubMed

Koneva, O Iu; Afonin, V Iu; Dromashko, S E

2006-01-01

The age-related changes in hemolymph cellular composition of snail Lymnaea stagnalis (Gastropoda, Pulmonata) obtained from individuals of a natural population (the river Pripayt, Gomel region, Belarus) as well as in the spectrum of cytomorphological traits of hemocyte genetic damages have been studied. The percentage of the distinguished hemolymph cell types during the chosen age period was not revealed to change. The percentage of cells with different morphological attributes of cell death varied during ageing. The tendency to increase in the total level of dying cells was observed.

Asymmetric-detection time-stretch optical microscopy (ATOM) for ultrafast high-contrast cellular imaging in flow

PubMed Central

Wong, Terence T. W.; Lau, Andy K. S.; Ho, Kenneth K. Y.; Tang, Matthew Y. H.; Robles, Joseph D. F.; Wei, Xiaoming; Chan, Antony C. S.; Tang, Anson H. L.; Lam, Edmund Y.; Wong, Kenneth K. Y.; Chan, Godfrey C. F.; Shum, Ho Cheung; Tsia, Kevin K.

2014-01-01

Accelerating imaging speed in optical microscopy is often realized at the expense of image contrast, image resolution, and detection sensitivity – a common predicament for advancing high-speed and high-throughput cellular imaging. We here demonstrate a new imaging approach, called asymmetric-detection time-stretch optical microscopy (ATOM), which can deliver ultrafast label-free high-contrast flow imaging with well delineated cellular morphological resolution and in-line optical image amplification to overcome the compromised imaging sensitivity at high speed. We show that ATOM can separately reveal the enhanced phase-gradient and absorption contrast in microfluidic live-cell imaging at a flow speed as high as ~10 m/s, corresponding to an imaging throughput of ~100,000 cells/sec. ATOM could thus be the enabling platform to meet the pressing need for intercalating optical microscopy in cellular assay, e.g. imaging flow cytometry – permitting high-throughput access to the morphological information of the individual cells simultaneously with a multitude of parameters obtained in the standard assay. PMID:24413677

High content image analysis for human H4 neuroglioma cells exposed to CuO nanoparticles.

PubMed

Li, Fuhai; Zhou, Xiaobo; Zhu, Jinmin; Ma, Jinwen; Huang, Xudong; Wong, Stephen T C

2007-10-09

High content screening (HCS)-based image analysis is becoming an important and widely used research tool. Capitalizing this technology, ample cellular information can be extracted from the high content cellular images. In this study, an automated, reliable and quantitative cellular image analysis system developed in house has been employed to quantify the toxic responses of human H4 neuroglioma cells exposed to metal oxide nanoparticles. This system has been proved to be an essential tool in our study. The cellular images of H4 neuroglioma cells exposed to different concentrations of CuO nanoparticles were sampled using IN Cell Analyzer 1000. A fully automated cellular image analysis system has been developed to perform the image analysis for cell viability. A multiple adaptive thresholding method was used to classify the pixels of the nuclei image into three classes: bright nuclei, dark nuclei, and background. During the development of our image analysis methodology, we have achieved the followings: (1) The Gaussian filtering with proper scale has been applied to the cellular images for generation of a local intensity maximum inside each nucleus; (2) a novel local intensity maxima detection method based on the gradient vector field has been established; and (3) a statistical model based splitting method was proposed to overcome the under segmentation problem. Computational results indicate that 95.9% nuclei can be detected and segmented correctly by the proposed image analysis system. The proposed automated image analysis system can effectively segment the images of human H4 neuroglioma cells exposed to CuO nanoparticles. The computational results confirmed our biological finding that human H4 neuroglioma cells had a dose-dependent toxic response to the insult of CuO nanoparticles.

Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging

DTIC Science & Technology

2016-03-01

Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging THESIS MARCH 2016 Kyle A. Palko, Second Lieutenant, USAF AFIT...declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM...PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM DISORDER THROUGH BRAIN FUNCTIONAL MAGNETIC RESONANCE IMAGING Kyle

Image compression-encryption algorithms by combining hyper-chaotic system with discrete fractional random transform

NASA Astrophysics Data System (ADS)

Gong, Lihua; Deng, Chengzhi; Pan, Shumin; Zhou, Nanrun

2018-07-01

Based on hyper-chaotic system and discrete fractional random transform, an image compression-encryption algorithm is designed. The original image is first transformed into a spectrum by the discrete cosine transform and the resulting spectrum is compressed according to the method of spectrum cutting. The random matrix of the discrete fractional random transform is controlled by a chaotic sequence originated from the high dimensional hyper-chaotic system. Then the compressed spectrum is encrypted by the discrete fractional random transform. The order of DFrRT and the parameters of the hyper-chaotic system are the main keys of this image compression and encryption algorithm. The proposed algorithm can compress and encrypt image signal, especially can encrypt multiple images once. To achieve the compression of multiple images, the images are transformed into spectra by the discrete cosine transform, and then the spectra are incised and spliced into a composite spectrum by Zigzag scanning. Simulation results demonstrate that the proposed image compression and encryption algorithm is of high security and good compression performance.

A new concept for medical imaging centered on cellular phone technology.

PubMed

Granot, Yair; Ivorra, Antoni; Rubinsky, Boris

2008-04-30

According to World Health Organization reports, some three quarters of the world population does not have access to medical imaging. In addition, in developing countries over 50% of medical equipment that is available is not being used because it is too sophisticated or in disrepair or because the health personnel are not trained to use it. The goal of this study is to introduce and demonstrate the feasibility of a new concept in medical imaging that is centered on cellular phone technology and which may provide a solution to medical imaging in underserved areas. The new system replaces the conventional stand-alone medical imaging device with a new medical imaging system made of two independent components connected through cellular phone technology. The independent units are: a) a data acquisition device (DAD) at a remote patient site that is simple, with limited controls and no image display capability and b) an advanced image reconstruction and hardware control multiserver unit at a central site. The cellular phone technology transmits unprocessed raw data from the patient site DAD and receives and displays the processed image from the central site. (This is different from conventional telemedicine where the image reconstruction and control is at the patient site and telecommunication is used to transmit processed images from the patient site). The primary goal of this study is to demonstrate that the cellular phone technology can function in the proposed mode. The feasibility of the concept is demonstrated using a new frequency division multiplexing electrical impedance tomography system, which we have developed for dynamic medical imaging, as the medical imaging modality. The system is used to image through a cellular phone a simulation of breast cancer tumors in a medical imaging diagnostic mode and to image minimally invasive tissue ablation with irreversible electroporation in a medical imaging interventional mode.

Correlating two-photon excited fluorescence imaging of breast cancer cellular redox state with seahorse flux analysis of normalized cellular oxygen consumption

NASA Astrophysics Data System (ADS)

Hou, Jue; Wright, Heather J.; Chan, Nicole; Tran, Richard; Razorenova, Olga V.; Potma, Eric O.; Tromberg, Bruce J.

2016-06-01

Two-photon excited fluorescence (TPEF) imaging of the cellular cofactors nicotinamide adenine dinucleotide and oxidized flavin adenine dinucleotide is widely used to measure cellular metabolism, both in normal and pathological cells and tissues. When dual-wavelength excitation is used, ratiometric TPEF imaging of the intrinsic cofactor fluorescence provides a metabolic index of cells-the "optical redox ratio" (ORR). With increased interest in understanding and controlling cellular metabolism in cancer, there is a need to evaluate the performance of ORR in malignant cells. We compare TPEF metabolic imaging with seahorse flux analysis of cellular oxygen consumption in two different breast cancer cell lines (MCF-7 and MDA-MB-231). We monitor metabolic index in living cells under both normal culture conditions and, for MCF-7, in response to cell respiration inhibitors and uncouplers. We observe a significant correlation between the TPEF-derived ORR and the flux analyzer measurements (R=0.7901, p<0.001). Our results confirm that the ORR is a valid dynamic index of cell metabolism under a range of oxygen consumption conditions relevant for cancer imaging.

Red-shifted aequorin-based bioluminescent reporters for in vivo imaging of Ca2 signaling.

PubMed

Curie, Thomas; Rogers, Kelly L; Colasante, Cesare; Brûlet, Philippe

2007-01-01

Real-time visualization of calcium (Ca(2+)) dynamics in the whole animal will enable important advances in understanding the complexities of cellular function. The genetically encoded bioluminescent Ca(2+) reporter green fluorescent protein-aequorin (GA) allows noninvasive detection of intracellular Ca(2+) signaling in freely moving mice. However, the emission spectrum of GA is not optimal for detection of activity from deep tissues in the whole animal. To overcome this limitation, two new reporter genes were constructed by fusing the yellow fluorescent protein (Venus) and the monomeric red fluorescent protein (mRFP1) to aequorin. Transfer of aequorin chemiluminescence energy to Venus (VA) is highly efficient and produces a 58 nm red shift in the peak emission spectrum of aequorin. This substantially improves photon transmission through tissue, such as the skin and thoracic cage. Although the Ca(2+)-induced bioluminescence spectrum of mRFP1-aequorin (RA) is similar to that of aequorin, there is also a small peak above 600 nm corresponding to the peak emission of mRFP1. Small amounts of energy transfer between aequorin and mRFP1 yield an emission spectrum with the highest percentage of total light above 600 nm compared with GA and VA. Accordingly, RA is also detected with higher sensitivity from brain areas. VA and RA will therefore improve optical access to Ca(2+) signaling events in deeper tissues, such as the heart and brain, and offer insight for engineering new hybrid molecules.

Generating porosity spectrum of carbonate reservoirs using ultrasonic imaging log

NASA Astrophysics Data System (ADS)

Zhang, Jie; Nie, Xin; Xiao, Suyun; Zhang, Chong; Zhang, Chaomo; Zhang, Zhansong

2018-03-01

Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity ϕ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the micro-resistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

Noninvasive amide proton transfer magnetic resonance imaging in evaluating the grading and cellularity of gliomas.

PubMed

Bai, Yan; Lin, Yusong; Zhang, Wei; Kong, Lingfei; Wang, Lifu; Zuo, Panli; Vallines, Ignacio; Schmitt, Benjamin; Tian, Jie; Song, Xiaolei; Zhou, Jinyuan; Wang, Meiyun

2017-01-24

Using noninvasive magnetic resonance imaging techniques to accurately evaluate the grading and cellularity of gliomas is beneficial for improving the patient outcomes. Amide proton transfer imaging is a noninvasive molecular magnetic resonance imaging technique based on chemical exchange saturation transfer mechanism that detects endogenous mobile proteins and peptides in biological tissues. Between August 2012 and November 2015, a total number of 44 patients with pathologically proven gliomas were included in this study. We compared the capability of amide proton transfer magnetic resonance imaging with that of noninvasive diffusion-weighted imaging and noninvasive 3-dimensional pseudo-continuous arterial spin imaging in evaluating the grading and cellularity of gliomas. Our results reveal that amide proton transfer magnetic resonance imaging is a superior imaging technique to diffusion-weighted imaging and 3-dimensional pseudo-continuous arterial spin imaging in the grading of gliomas. In addition, our results showed that the Ki-67 index correlated better with the amide proton transfer-weighted signal intensity than with the apparent diffusion coefficient value or the cerebral blood flow value in the gliomas. Amide proton transfer magnetic resonance imaging is a promising method for predicting the grading and cellularity of gliomas.

Live CLEM imaging to analyze nuclear structures at high resolution.

PubMed

Haraguchi, Tokuko; Osakada, Hiroko; Koujin, Takako

2015-01-01

Fluorescence microscopy (FM) and electron microscopy (EM) are powerful tools for observing molecular components in cells. FM can provide temporal information about cellular proteins and structures in living cells. EM provides nanometer resolution images of cellular structures in fixed cells. We have combined FM and EM to develop a new method of correlative light and electron microscopy (CLEM), called "Live CLEM." In this method, the dynamic behavior of specific molecules of interest is first observed in living cells using fluorescence microscopy (FM) and then cellular structures in the same cell are observed using electron microscopy (EM). Following image acquisition, FM and EM images are compared to enable the fluorescent images to be correlated with the high-resolution images of cellular structures obtained using EM. As this method enables analysis of dynamic events involving specific molecules of interest in the context of specific cellular structures at high resolution, it is useful for the study of nuclear structures including nuclear bodies. Here we describe Live CLEM that can be applied to the study of nuclear structures in mammalian cells.

Mechanochemistry of Chitosan-Coated Zinc Sulfide (ZnS) Nanocrystals for Bio-imaging Applications.

PubMed

Bujňáková, Zdenka; Dutková, Erika; Kello, Martin; Mojžiš, Ján; Baláž, Matej; Baláž, Peter; Shpotyuk, Oleh

2017-12-01

The ZnS nanocrystals were prepared in chitosan solution (0.1 wt.%) using a wet ultra-fine milling. The obtained suspension was stable and reached high value of zeta potential (+57 mV). The changes in FTIR spectrum confirmed the successful surface coating of ZnS nanoparticles by chitosan. The prepared ZnS nanocrystals possessed interesting optical properties verified in vitro. Four cancer cells were selected (CaCo-2, HCT116, HeLa, and MCF-7), and after their treatment with the nanosuspension, the distribution of ZnS in the cells was studied using a fluorescence microscope. The particles were clearly seen; they passed through the cell membrane and accumulated in cytosol. The biological activity of the cells was not influenced by nanoparticles, they did not cause cell death, and only the granularity of cells was increased as a consequence of cellular uptake. These results confirm the potential of ZnS nanocrystals using in bio-imaging applications.

Non-invasive intravital imaging of cellular differentiation with a bright red-excitable fluorescent protein

PubMed Central

Chu, Jun; Haynes, Russell D; Corbel, Stéphane Y; Li, Pengpeng; González-González, Emilio; Burg, John S; Ataie, Niloufar J; Lam, Amy J; Cranfill, Paula J; Baird, Michelle A; Davidson, Michael W; Ng, Ho-Leung; Garcia, K Christopher; Contag, Christopher H; Shen, Kang; Blau, Helen M; Lin, Michael Z

2014-01-01

A method for non-invasive visualization of genetically labelled cells in animal disease models with micron-level resolution would greatly facilitate development of cell-based therapies. Imaging of fluorescent proteins (FPs) using red excitation light in the “optical window” above 600 nm is one potential method for visualizing implanted cells. However, previous efforts to engineer FPs with peak excitation beyond 600 nm have resulted in undesirable reductions in brightness. Here we report three new red-excitable monomeric FPs obtained by structure-guided mutagenesis of mNeptune, previously the brightest monomeric FP when excited beyond 600 nm. Two of these, mNeptune2 and mNeptune2.5, demonstrate improved maturation and brighter fluorescence, while the third, mCardinal, has a red-shifted excitation spectrum without reduction in brightness. We show that mCardinal can be used to non-invasively and longitudinally visualize the differentiation of myoblasts and stem cells into myocytes in living mice with high anatomical detail. PMID:24633408

Mechanochemistry of Chitosan-Coated Zinc Sulfide (ZnS) Nanocrystals for Bio-imaging Applications

NASA Astrophysics Data System (ADS)

Bujňáková, Zdenka; Dutková, Erika; Kello, Martin; Mojžiš, Ján; Baláž, Matej; Baláž, Peter; Shpotyuk, Oleh

2017-05-01

The ZnS nanocrystals were prepared in chitosan solution (0.1 wt.%) using a wet ultra-fine milling. The obtained suspension was stable and reached high value of zeta potential (+57 mV). The changes in FTIR spectrum confirmed the successful surface coating of ZnS nanoparticles by chitosan. The prepared ZnS nanocrystals possessed interesting optical properties verified in vitro. Four cancer cells were selected (CaCo-2, HCT116, HeLa, and MCF-7), and after their treatment with the nanosuspension, the distribution of ZnS in the cells was studied using a fluorescence microscope. The particles were clearly seen; they passed through the cell membrane and accumulated in cytosol. The biological activity of the cells was not influenced by nanoparticles, they did not cause cell death, and only the granularity of cells was increased as a consequence of cellular uptake. These results confirm the potential of ZnS nanocrystals using in bio-imaging applications.

Cellular imaging of deep organ using two-photon Bessel light-sheet nonlinear structured illumination microscopy

PubMed Central

Zhao, Ming; Zhang, Han; Li, Yu; Ashok, Amit; Liang, Rongguang; Zhou, Weibin; Peng, Leilei

2014-01-01

In vivo fluorescent cellular imaging of deep internal organs is highly challenging, because the excitation needs to penetrate through strong scattering tissue and the emission signal is degraded significantly by photon diffusion induced by tissue-scattering. We report that by combining two-photon Bessel light-sheet microscopy with nonlinear structured illumination microscopy (SIM), live samples up to 600 microns wide can be imaged by light-sheet microscopy with 500 microns penetration depth, and diffused background in deep tissue light-sheet imaging can be reduced to obtain clear images at cellular resolution in depth beyond 200 microns. We demonstrate in vivo two-color imaging of pronephric glomeruli and vasculature of zebrafish kidney, whose cellular structures located at the center of the fish body are revealed in high clarity by two-color two-photon Bessel light-sheet SIM. PMID:24876996

Fusion of multi-spectral and panchromatic images based on 2D-PWVD and SSIM

NASA Astrophysics Data System (ADS)

Tan, Dongjie; Liu, Yi; Hou, Ruonan; Xue, Bindang

2016-03-01

A combined method using 2D pseudo Wigner-Ville distribution (2D-PWVD) and structural similarity(SSIM) index is proposed for fusion of low resolution multi-spectral (MS) image and high resolution panchromatic (PAN) image. First, the intensity component of multi-spectral image is extracted with generalized IHS transform. Then, the spectrum diagrams of the intensity components of multi-spectral image and panchromatic image are obtained with 2D-PWVD. Different fusion rules are designed for different frequency information of the spectrum diagrams. SSIM index is used to evaluate the high frequency information of the spectrum diagrams for assigning the weights in the fusion processing adaptively. After the new spectrum diagram is achieved according to the fusion rule, the final fusion image can be obtained by inverse 2D-PWVD and inverse GIHS transform. Experimental results show that, the proposed method can obtain high quality fusion images.

SPED light sheet microscopy: fast mapping of biological system structure and function

PubMed Central

Tomer, Raju; Lovett-Barron, Matthew; Kauvar, Isaac; Andalman, Aaron; Burns, Vanessa M.; Sankaran, Sethuraman; Grosenick, Logan; Broxton, Michael; Yang, Samuel; Deisseroth, Karl

2016-01-01

The goal of understanding living nervous systems has driven interest in high-speed and large field-of-view volumetric imaging at cellular resolution. Light-sheet microscopy approaches have emerged for cellular-resolution functional brain imaging in small organisms such as larval zebrafish, but remain fundamentally limited in speed. Here we have developed SPED light sheet microscopy, which combines large volumetric field-of-view via an extended depth of field with the optical sectioning of light sheet microscopy, thereby eliminating the need to physically scan detection objectives for volumetric imaging. SPED enables scanning of thousands of volumes-per-second, limited only by camera acquisition rate, through the harnessing of optical mechanisms that normally result in unwanted spherical aberrations. We demonstrate capabilities of SPED microscopy by performing fast sub-cellular resolution imaging of CLARITY mouse brains and cellular-resolution volumetric Ca2+ imaging of entire zebrafish nervous systems. Together, SPED light sheet methods enable high-speed cellular-resolution volumetric mapping of biological system structure and function. PMID:26687363

A mitochondria-selective near-infrared-emitting fluorescent dye for cellular imaging studies.

PubMed

Choi, Peter; Noguchi, Katsuya; Ishiyama, Munetaka; Denny, William A; Jose, Jiney

2018-05-03

This communication details the synthesis, evaluation of photophysical properties, and cellular imaging studies of cyanine chromophore based fluorescent dye 1 as a selective imaging agent for mitochondria. Copyright © 2018 Elsevier Ltd. All rights reserved.

Spectrum image analysis tool - A flexible MATLAB solution to analyze EEL and CL spectrum images.

PubMed

Schmidt, Franz-Philipp; Hofer, Ferdinand; Krenn, Joachim R

2017-02-01

Spectrum imaging techniques, gaining simultaneously structural (image) and spectroscopic data, require appropriate and careful processing to extract information of the dataset. In this article we introduce a MATLAB based software that uses three dimensional data (EEL/CL spectrum image in dm3 format (Gatan Inc.'s DigitalMicrograph ® )) as input. A graphical user interface enables a fast and easy mapping of spectral dependent images and position dependent spectra. First, data processing such as background subtraction, deconvolution and denoising, second, multiple display options including an EEL/CL moviemaker and, third, the applicability on a large amount of data sets with a small work load makes this program an interesting tool to visualize otherwise hidden details. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pan-neuronal calcium imaging with cellular resolution in freely swimming zebrafish.

PubMed

Kim, Dal Hyung; Kim, Jungsoo; Marques, João C; Grama, Abhinav; Hildebrand, David G C; Gu, Wenchao; Li, Jennifer M; Robson, Drew N

2017-11-01

Calcium imaging with cellular resolution typically requires an animal to be tethered under a microscope, which substantially restricts the range of behaviors that can be studied. To expand the behavioral repertoire amenable to imaging, we have developed a tracking microscope that enables whole-brain calcium imaging with cellular resolution in freely swimming larval zebrafish. This microscope uses infrared imaging to track a target animal in a behavior arena. On the basis of the predicted trajectory of the animal, we applied optimal control theory to a motorized stage system to cancel brain motion in three dimensions. We combined this motion-cancellation system with differential illumination focal filtering, a variant of HiLo microscopy, which enabled us to image the brain of a freely swimming larval zebrafish for more than an hour. This work expands the repertoire of natural behaviors that can be studied with cellular-resolution calcium imaging to potentially include spatial navigation, social behavior, feeding and reward.

Nonlinear spectral imaging of biological tissues

NASA Astrophysics Data System (ADS)

Palero, J. A.

2007-07-01

The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal. Because biological intrinsic emission is generally very weak and extends from the ultraviolet to the visible spectral range, a broad-spectral range and high sensitivity 3D spectral imaging system is developed. Imaging the spectral characteristics of the biological intrinsic emission reveals the structure and biochemistry of the cells and extra-cellular components. By using different methods in visualizing the spectral images, discrimination between different tissue structures is achieved without the use of any stain or fluorescent label. For instance, RGB real color spectral images of the intrinsic emission of mouse skin tissues show blue cells, green hair follicles, and purple collagen fibers. The color signature of each tissue component is directly related to its characteristic emission spectrum. The results of this study show that skin tissue nonlinear intrinsic emission is mainly due to the autofluorescence of reduced nicotinamide adenine dinucleotide (phosphate), flavins, keratin, melanin, phospholipids, elastin and collagen and nonlinear Raman scattering and second-harmonic generation in Type I collagen. In vivo time-lapse spectral imaging is implemented to study metabolic changes in epidermal cells in tissues. Optical scattering in tissues, a key factor in determining the maximum achievable imaging depth, is also investigated in this work.

Reconstructing Face Image from the Thermal Infrared Spectrum to the Visible Spectrum †

PubMed Central

Kresnaraman, Brahmastro; Deguchi, Daisuke; Takahashi, Tomokazu; Mekada, Yoshito; Ide, Ichiro; Murase, Hiroshi

2016-01-01

During the night or in poorly lit areas, thermal cameras are a better choice instead of normal cameras for security surveillance because they do not rely on illumination. A thermal camera is able to detect a person within its view, but identification from only thermal information is not an easy task. The purpose of this paper is to reconstruct the face image of a person from the thermal spectrum to the visible spectrum. After the reconstruction, further image processing can be employed, including identification/recognition. Concretely, we propose a two-step thermal-to-visible-spectrum reconstruction method based on Canonical Correlation Analysis (CCA). The reconstruction is done by utilizing the relationship between images in both thermal infrared and visible spectra obtained by CCA. The whole image is processed in the first step while the second step processes patches in an image. Results show that the proposed method gives satisfying results with the two-step approach and outperforms comparative methods in both quality and recognition evaluations. PMID:27110781

Shaping dendritic spines in autism spectrum disorder: mTORC1-dependent macroautophagy.

PubMed

Bowling, Heather; Klann, Eric

2014-09-03

In this issue of Neuron, Tang et al. (2014) explore the relationship between developmental dendritic pruning, elevated mTORC1 signaling, macroautophagy, and autism spectrum disorder. The study provides valuable new insight into mTORC1-dependent cellular dysfunction and neurodevelopmental disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Comorbidity of Allergic and Autoimmune Diseases in Patients with Autism Spectrum Disorder: A Nationwide Population-Based Study

ERIC Educational Resources Information Center

Chen, Mu-Hong; Su, Tung-Ping; Chen, Ying-Sheue; Hsu, Ju-Wei; Huang, Kai-Lin; Chang, Wen-Han; Chen, Tzeng-Ji; Bai, Ya-Mei

2013-01-01

Previous clinical and genetic studies have suggested autism spectrum disorders (ASDs) is associated with immunological abnormalities involving cytokines, immunoglobulins, inflammation, and cellular immunity, but epidemiological reports are still limited. Patients with ASDs were identified in the National Health Insurance Database from 1996 to…

Characterizing active cytoskeletal dynamics with magnetic microposts

NASA Astrophysics Data System (ADS)

Shi, Yu; Henry, Steven; Crocker, John; Reich, Daniel

Characterization of an active matter system such as the cellular cytoskeleton requires knowledge of three frequency dependent quantities: the dynamic shear modulus, G*(ω) describing its viscoelasticity, the Fourier power spectrum of forces in the material due to internal force generators f (ω) , and the spectrum of the material's active strain fluctuations x(ω) . Via use of PDMS micropost arrays with magnetic nanowires embedded in selected posts, we measure the local complex modulus of cells through mechanical actuation of the magnetic microposts. The micrometer scale microposts are also used as passive probes to measure simultaneously the frequency dependent strain fluctuations. We present data on 3T3 fibroblasts, where we find power law behavior for both the frequency dependence of cells' modulus | G (ω) | ω 0 . 27 and the power spectrum of strain fluctuations |x(ω) | ω-2 . Results for the power spectrum of active cytoskeletal stresses determined from these two measurements, and implications of this mesoscale characterization of cytoskeletal dynamics for cellular biophysics will also be discussed. Supported in part by NIH Grant 1R01HL127087.

Force-activatable coating enables high-resolution cellular force imaging directly on regular cell culture surfaces.

PubMed

Sarkar, Anwesha; Zhao, Yuanchang; Wang, Yongliang; Wang, Xuefeng

2018-06-25

Integrin-transmitted cellular forces are crucial mechanical signals regulating a vast range of cell functions. Although various methods have been developed to visualize and quantify cellular forces at the cell-matrix interface, a method with high performance and low technical barrier is still in demand. Here we developed a force-activatable coating (FAC), which can be simply coated on regular cell culture apparatus' surfaces by physical adsorption, and turn these surfaces to force reporting platforms that enable cellular force mapping directly by fluorescence imaging. The FAC molecule consists of an adhesive domain for surface coating and a force-reporting domain which can be activated to fluoresce by integrin molecular tension. The tension threshold required for FAC activation is tunable in 10-60 piconewton (pN), allowing the selective imaging of cellular force contributed by integrin tension at different force levels. We tested the performance of two FACs with tension thresholds of 12 and 54 pN (nominal values), respectively, on both glass and polystyrene surfaces. Cellular forces were successfully mapped by fluorescence imaging on all the surfaces. FAC-coated surfaces also enable co-imaging of cellular forces and cell structures in both live cells and immunostained cells, therefore opening a new avenue for the study of the interplay of force and structure. We demonstrated the co-imaging of integrin tension and talin clustering in live cells, and concluded that talin clustering always occurs before the generation of integrin tension above 54 pN, reinforcing the notion that talin is an important adaptor protein for integrin tension transmission. Overall, FAC provides a highly convenient approach that is accessible to general biological laboratories for the study of cellular forces with high sensitivity and resolution, thus holding the potential to greatly boost the research of cell mechanobiology.

[A Method to Reconstruct Surface Reflectance Spectrum from Multispectral Image Based on Canopy Radiation Transfer Model].

PubMed

Zhao, Yong-guang; Ma, Ling-ling; Li, Chuan-rong; Zhu, Xiao-hua; Tang, Ling-li

2015-07-01

Due to the lack of enough spectral bands for multi-spectral sensor, it is difficult to reconstruct surface retlectance spectrum from finite spectral information acquired by multi-spectral instrument. Here, taking into full account of the heterogeneity of pixel from remote sensing image, a method is proposed to simulate hyperspectral data from multispectral data based on canopy radiation transfer model. This method first assumes the mixed pixels contain two types of land cover, i.e., vegetation and soil. The sensitive parameters of Soil-Leaf-Canopy (SLC) model and a soil ratio factor were retrieved from multi-spectral data based on Look-Up Table (LUT) technology. Then, by combined with a soil ratio factor, all the parameters were input into the SLC model to simulate the surface reflectance spectrum from 400 to 2 400 nm. Taking Landsat Enhanced Thematic Mapper Plus (ETM+) image as reference image, the surface reflectance spectrum was simulated. The simulated reflectance spectrum revealed different feature information of different surface types. To test the performance of this method, the simulated reflectance spectrum was convolved with the Landsat ETM + spectral response curves and Moderate Resolution Imaging Spectrometer (MODIS) spectral response curves to obtain the simulated Landsat ETM+ and MODIS image. Finally, the simulated Landsat ETM+ and MODIS images were compared with the observed Landsat ETM+ and MODIS images. The results generally showed high correction coefficients (Landsat: 0.90-0.99, MODIS: 0.74-0.85) between most simulated bands and observed bands and indicated that the simulated reflectance spectrum was well simulated and reliable.

Luminescent single-walled carbon nanotube-sensitized europium nanoprobes for cellular imaging

PubMed Central

Avti, Pramod K; Sitharaman, Balaji

2012-01-01

Lanthanoid-based optical probes with excitation wavelengths in the ultra-violet (UV) range (300–325 nm) have been widely developed as imaging probes. Efficient cellular imaging requires that lanthanoid optical probes be excited at visible wavelengths, to avoid UV damage to cells. The efficacy of europium-catalyzed single-walled carbon nanotubes (Eu-SWCNTs), as visible nanoprobes for cellular imaging, is reported in this study. Confocal fluorescence microscopy images of breast cancer cells (SK-BR-3 and MCF-7) and normal cells (NIH 3T3), treated with Eu-SWCNT at 0.2 μg/mL concentration, showed bright red luminescence after excitation at 365 nm and 458 nm wavelengths. Cell viability analysis showed no cytotoxic effects after the incubation of cells with Eu-SWCNTs at this concentration. Eu-SWCNT uptake is via the endocytosis mechanism. Labeling efficiency, defined as the percentage of incubated cells that uptake Eu-SWCNT, was 95%–100% for all cell types. The average cellular uptake concentration was 6.68 ng Eu per cell. Intracellular localization was further corroborated by transmission electron microscopy and Raman microscopy. The results indicate that Eu-SWCNT shows potential as a novel cellular imaging probe, wherein SWCNT sensitizes Eu3+ ions to allow excitation at visible wavelengths, and stable time-resolved red emission. The ability to functionalize biomolecules on the exterior surface of Eu-SWCNT makes it an excellent candidate for targeted cellular imaging. PMID:22619533

Surface-enhanced Raman scattering of whole human blood, blood plasma, and red blood cells: cellular processes and bioanalytical sensing.

PubMed

Premasiri, W R; Lee, J C; Ziegler, L D

2012-08-09

SERS spectra of whole human blood, blood plasma, and red blood cells on Au nanoparticle SiO(2) substrates excited at 785 nm have been observed. For the sample preparation procedure employed here, the SERS spectrum of whole blood arises from the blood plasma component only. This is in contrast to the normal Raman spectrum of whole blood excited at 785 nm and open to ambient air, which is exclusively due to the scattering of oxyhemoglobin. The SERS spectrum of whole blood shows a storage time dependence that is not evident in the non-SERS Raman spectrum of whole blood. Hypoxanthine, a product of purine degradation, dominates the SERS spectrum of blood after ~10-20 h of storage at 8 °C. The corresponding SERS spectrum of plasma isolated from the stored blood shows the same temporal release of hypoxanthine. Thus, blood cellular components (red blood cells, white blood cells, and/or platelets) are releasing hypoxanthine into the plasma over this time interval. The SERS spectrum of red blood cells (RBCs) excited at 785 nm is reported for the first time and exhibits well-known heme group marker bands as well as other bands that may be attributed to cell membrane components or protein denaturation contributions. SERS, as well as normal Raman spectra, of oxy- and met-RBCs are reported and compared. These SERS results can have significant impact in the area of clinical diagnostics, blood supply management, and forensics.

Surface Enhanced Raman Scattering of Whole Human Blood, Blood Plasma and Red Blood Cells: Cellular Processes and Bioanalytical Sensing

PubMed Central

Premasiri, W. R.; Lee, J. C.; Ziegler, L. D.

2013-01-01

SERS spectra of whole human blood, blood plasma and red blood cells on Au nanoparticle SiO2 substrates excited at 785 nm have been observed. For the sample preparation procedure employed here, the SERS spectrum of whole blood arises from the blood plasma component only. This is in contrast to the normal Raman spectrum of whole blood excited at 785 nm and open to ambient air, which is exclusively due to the scattering of oxyhemoglobin. The SERS spectrum of whole blood shows a storage time dependence that is not evident in the non-SERS Raman spectrum of whole blood. Hypoxanthine, a product of purine degradation, dominates the SERS spectrum of blood after ~10 – 20 hours of storage at 8 °C. The corresponding SERS spectrum of plasma isolated from the stored blood shows the same temporal release of hypoxanthine. Thus, blood cellular components (red blood cells, white blood cells and/or platelets) are releasing hypoxanthine into the plasma over this time interval. The SERS spectrum of red blood cells (RBCs) excited at 785 nm is reported for the first time and exhibits well known heme group marker bands, as well as other bands that may be attributed to cell membrane components or protein denaturation contributions. SERS, as well as normal Raman spectra, of oxy- and met-RBCs are reported and compared. These SERS results can have significant impact in the area of clinical diagnostics, blood supply management and forensics. PMID:22780445

Color image encryption based on hybrid hyper-chaotic system and cellular automata

NASA Astrophysics Data System (ADS)

Yaghouti Niyat, Abolfazl; Moattar, Mohammad Hossein; Niazi Torshiz, Masood

2017-03-01

This paper proposes an image encryption scheme based on Cellular Automata (CA). CA is a self-organizing structure with a set of cells in which each cell is updated by certain rules that are dependent on a limited number of neighboring cells. The major disadvantages of cellular automata in cryptography include limited number of reversal rules and inability to produce long sequences of states by these rules. In this paper, a non-uniform cellular automata framework is proposed to solve this problem. This proposed scheme consists of confusion and diffusion steps. In confusion step, the positions of the original image pixels are replaced by chaos mapping. Key image is created using non-uniform cellular automata and then the hyper-chaotic mapping is used to select random numbers from the image key for encryption. The main contribution of the paper is the application of hyper chaotic functions and non-uniform CA for robust key image generation. Security analysis and experimental results show that the proposed method has a very large key space and is resistive against noise and attacks. The correlation between adjacent pixels in the encrypted image is reduced and the amount of entropy is equal to 7.9991 which is very close to 8 which is ideal.

In vivo cellular imaging with microscopes enabled by MEMS scanners

NASA Astrophysics Data System (ADS)

Ra, Hyejun

High-resolution optical imaging plays an important role in medical diagnosis and biomedical research. Confocal microscopy is a widely used imaging method for obtaining cellular and sub-cellular images of biological tissue in reflectance and fluorescence modes. Its characteristic optical sectioning capability also enables three-dimensional (3-D) image reconstruction. However, its use has mostly been limited to excised tissues due to the requirement of high numerical aperture (NA) lenses for cellular resolution. Microscope miniaturization can enable in vivo imaging to make possible early cancer diagnosis and biological studies in the innate environment. In this dissertation, microscope miniaturization for in vivo cellular imaging is presented. The dual-axes confocal (DAC) architecture overcomes limitations of the conventional single-axis confocal (SAC) architecture to allow for miniaturization with high resolution. A microelectromechanical systems (MEMS) scanner is the central imaging component that is key in miniaturization of the DAC architecture. The design, fabrication, and characterization of the two-dimensional (2-D) MEMS scanner are presented. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer and is actuated by self-aligned vertical electrostatic combdrives. The imaging performance of the MEMS scanner in a DAC configuration is shown in a breadboard microscope setup, where reflectance and fluorescence imaging is demonstrated. Then, the MEMS scanner is integrated into a miniature DAC microscope. The whole imaging system is integrated into a portable unit for research in small animal models of human biology and disease. In vivo 3-D imaging is demonstrated on mouse skin models showing gene transfer and siRNA silencing. The siRNA silencing process is sequentially imaged in one mouse over time.

Detecting the Extent of Cellular Decomposition after Sub-Eutectoid Annealing in Rolled UMo Foils

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

Kautz, Elizabeth J.; Jana, Saumyadeep; Devaraj, Arun

2017-07-31

This report presents an automated image processing approach to quantifying microstructure image data, specifically the extent of eutectoid (cellular) decomposition in rolled U-10Mo foils. An image processing approach is used here to be able to quantitatively describe microstructure image data in order to relate microstructure to processing parameters (time, temperature, deformation).

Preferential tumor cellular uptake and retention of indocyanine green for in vivo tumor imaging.

PubMed

Onda, Nobuhiko; Kimura, Masayuki; Yoshida, Toshinori; Shibutani, Makoto

2016-08-01

Indocyanine green (ICG) is a fluorescent agent approved for clinical applications by the Food and Drug Administration and European Medicines Agency. This study examined the mechanism of tumor imaging using intravenously administered ICG. The in vivo kinetics of intravenously administered ICG were determined in tumor xenografts using microscopic approaches that enabled both spatio-temporal and high-magnification analyses. The mechanism of ICG-based tumor imaging was examined at the cellular level in six phenotypically different human colon cancer cell lines exhibiting different grades of epithelioid organization. ICG fluorescence imaging detected xenograft tumors, even those < 1 mm in size, based on their preferential cellular uptake and retention of the dye following its rapid tissue-non-specific delivery, in contrast to its rapid clearance by normal tissue. Live-cell imaging revealed that cellular ICG uptake is temperature-dependent and occurs after ICG binding to the cellular membrane, a pattern suggesting endocytic uptake as the mechanism. Cellular ICG uptake correlated inversely with the formation of tight junctions. Intracellular ICG was entrapped in the membrane traffic system, resulting in its slow turnover and prolonged retention by tumor cells. Our results suggest that tumor-specific imaging by ICG involves non-specific delivery of the dye to tissues followed by preferential tumor cellular uptake and retention. The tumor cell-preference of ICG is driven by passive tumor cell-targeting, the inherent ability of ICG to bind to cell membranes, and the high endocytic activity of tumor cells in association with the disruption of their tight junctions. © 2016 UICC.

Nanobodies and recombinant binders in cell biology

PubMed Central

Helma, Jonas; Cardoso, M. Cristina; Muyldermans, Serge

2015-01-01

Antibodies are key reagents to investigate cellular processes. The development of recombinant antibodies and binders derived from natural protein scaffolds has expanded traditional applications, such as immunofluorescence, binding arrays, and immunoprecipitation. In addition, their small size and high stability in ectopic environments have enabled their use in all areas of cell research, including structural biology, advanced microscopy, and intracellular expression. Understanding these novel reagents as genetic modules that can be integrated into cellular pathways opens up a broad experimental spectrum to monitor and manipulate cellular processes. PMID:26056137

Photocleavable Hydrogel-Coated Upconverting Nanoparticles: A Multifunctional Theranostic Platform for NIR Imaging and On-Demand Macromolecular Delivery.

PubMed

Jalani, Ghulam; Naccache, Rafik; Rosenzweig, Derek H; Haglund, Lisbet; Vetrone, Fiorenzo; Cerruti, Marta

2016-01-27

Lanthanide-doped upconverting nanoparticles (UCNPs) have emerged as excellent nanotransducers for converting longer wavelength near-infrared (NIR) light to shorter wavelengths spanning the ultraviolet (UV) to the visible (Vis) regions of the spectrum via a multiphoton absorption process, known as upconversion. Here, we report the development of NIR to UV-Vis-NIR UCNPs consisting of LiYF4:Yb(3+)/Tm(3+)@SiO2 individually coated with a 10 ± 2 nm layer of chitosan (CH) hydrogel cross-linked with a photocleavable cross-linker (PhL). We encapsulated fluorescent-bovine serum albumin (FITC-BSA) inside the gel. Under 980 nm excitation, the upconverted UV emission cleaves the PhL cross-links and instantaneously liberates the FITC-BSA under 2 cm thick tissue. The release is immediately arrested if the excitation source is switched off. The upconverted NIR light allows for the tracking of particles under the tissue. Nucleus pulposus (NP) cells cultured with UCNPs are viable both in the presence and in the absence of laser irradiation. Controlled drug delivery of large biomolecules and deep tissue imaging make this system an excellent theranostic platform for tissue engineering, biomapping, and cellular imaging applications.

Optical Coherence Microscopy

NASA Astrophysics Data System (ADS)

Aguirre, Aaron D.; Zhou, Chao; Lee, Hsiang-Chieh; Ahsen, Osman O.; Fujimoto, James G.

Cellular imaging of human tissues remains an important advance for many clinical applications of optical coherence tomography (OCT). Imaging cells with traditional OCT systems has not been possible due to the limited transverse resolution of such techniques. Optical coherence microscopy (OCM) refers to OCT methods that achieve high transverse resolution to visualize cells and subcellular features. This chapter provides a comprehensive discussion of the rationale for cellular imaging in human tissues as well as a review of the key technological advances required to achieve it. Time domain and Fourier domain OCM approaches are described with an emphasis on state of the art system designs, including miniaturized endoscopic imaging probes. Clinical applications are discussed and multiple examples of cellular imaging in human tissues are provided.

Multifunctional nanoparticle-EpCAM aptamer bioconjugates: a paradigm for targeted drug delivery and imaging in cancer therapy.

PubMed

Das, Manasi; Duan, Wei; Sahoo, Sanjeeb K

2015-02-01

The promising proposition of multifunctional nanoparticles for cancer diagnostics and therapeutics has inspired the development of theranostic approach for improved cancer therapy. Moreover, active targeting of drug carrier to specific target site is crucial for providing efficient delivery of therapeutics and imaging agents. In this regard, the present study investigates the theranostic capabilities of nutlin-3a loaded poly (lactide-co-glycolide) nanoparticles, functionalized with a targeting ligand (EpCAM aptamer) and an imaging agent (quantum dots) for cancer therapy and bioimaging. A wide spectrum of in vitro analysis (cellular uptake study, cytotoxicity assay, cell cycle and apoptosis analysis, apoptosis associated proteins study) revealed superior therapeutic potentiality of targeted NPs over other formulations in EpCAM expressing cells. Moreover, our nanotheranostic system served as a superlative bio-imaging modality both in 2D monolayer culture and tumor spheroid model. Our result suggests that, these aptamer-guided multifunctional NPs may act as indispensable nanotheranostic approach toward cancer therapy. This study investigated the theranostic capabilities of nutlin-3a loaded poly (lactide-co-glycolide) nanoparticles functionalized with a targeting ligand (EpCAM aptamer) and an imaging agent (quantum dots) for cancer therapy and bioimaging. It was concluded that the studied multifunctional targeted nanoparticle may become a viable and efficient approach in cancer therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Early brain enlargement and elevated extra-axial fluid in infants who develop autism spectrum disorder.

PubMed

Shen, Mark D; Nordahl, Christine W; Young, Gregory S; Wootton-Gorges, Sandra L; Lee, Aaron; Liston, Sarah E; Harrington, Kayla R; Ozonoff, Sally; Amaral, David G

2013-09-01

Prospective studies of infants at risk for autism spectrum disorder have provided important clues about the early behavioural symptoms of autism spectrum disorder. Diagnosis of autism spectrum disorder, however, is not currently made until at least 18 months of age. There is substantially less research on potential brain-based differences in the period between 6 and 12 months of age. Our objective in the current study was to use magnetic resonance imaging to identify any consistently observable brain anomalies in 6-9 month old infants who would later develop autism spectrum disorder. We conducted a prospective infant sibling study with longitudinal magnetic resonance imaging scans at three time points (6-9, 12-15, and 18-24 months of age), in conjunction with intensive behavioural assessments. Fifty-five infants (33 'high-risk' infants having an older sibling with autism spectrum disorder and 22 'low-risk' infants having no relatives with autism spectrum disorder) were imaged at 6-9 months; 43 of these (27 high-risk and 16 low-risk) were imaged at 12-15 months; and 42 (26 high-risk and 16 low-risk) were imaged again at 18-24 months. Infants were classified as meeting criteria for autism spectrum disorder, other developmental delays, or typical development at 24 months or later (mean age at outcome: 32.5 months). Compared with the other two groups, infants who developed autism spectrum disorder (n = 10) had significantly greater extra-axial fluid at 6-9 months, which persisted and remained elevated at 12-15 and 18-24 months. Extra-axial fluid is characterized by excessive cerebrospinal fluid in the subarachnoid space, particularly over the frontal lobes. The amount of extra-axial fluid detected as early as 6 months was predictive of more severe autism spectrum disorder symptoms at the time of outcome. Infants who developed autism spectrum disorder also had significantly larger total cerebral volumes at both 12-15 and 18-24 months of age. This is the first magnetic resonance imaging study to prospectively evaluate brain growth trajectories from infancy in children who develop autism spectrum disorder. The presence of excessive extra-axial fluid detected as early as 6 months and the lack of resolution by 24 months is a hitherto unreported brain anomaly in infants who later develop autism spectrum disorder. This is also the first magnetic resonance imaging evidence of brain enlargement in autism before age 2. These findings raise the potential for the use of structural magnetic resonance imaging to aid in the early detection of children at risk for autism spectrum disorder or other neurodevelopmental disorders.

Flame colour characterization in the visible and infrared spectrum using a digital camera and image processing

NASA Astrophysics Data System (ADS)

Huang, Hua-Wei; Zhang, Yang

2008-08-01

An attempt has been made to characterize the colour spectrum of methane flame under various burning conditions using RGB and HSV colour models instead of resolving the real physical spectrum. The results demonstrate that each type of flame has its own characteristic distribution in both the RGB and HSV space. It has also been observed that the averaged B and G values in the RGB model represent well the CH* and C*2 emission of methane premixed flame. Theses features may be utilized for flame measurement and monitoring. The great advantage of using a conventional camera for monitoring flame properties based on the colour spectrum is that it is readily available, easy to interface with a computer, cost effective and has certain spatial resolution. Furthermore, it has been demonstrated that a conventional digital camera is able to image flame not only in the visible spectrum but also in the infrared. This feature is useful in avoiding the problem of image saturation typically encountered in capturing the very bright sooty flames. As a result, further digital imaging processing and quantitative information extraction is possible. It has been identified that an infrared image also has its own distribution in both the RGB and HSV colour space in comparison with a flame image in the visible spectrum.

Close the Textbook & Open "The Cell: An Image Library"

ERIC Educational Resources Information Center

Saunders, Cheston; Taylor, Amy

2014-01-01

Many students leave the biology classroom with misconceptions centered on cellular structure. This article presents an activity in which students utilize images from an online database called "The Cell: An Image Library" (http://www.cellimagelibrary. org/) to gain a greater understanding of the diversity of cellular structure and the…

Dual-Modality, Dual-Functional Nanoprobes for Cellular and Molecular Imaging

PubMed Central

Menon, Jyothi U.; Gulaka, Praveen K.; McKay, Madalyn A.; Geethanath, Sairam; Liu, Li; Kodibagkar, Vikram D.

2012-01-01

An emerging need for evaluation of promising cellular therapies is a non-invasive method to image the movement and health of cells following transplantation. However, the use of a single modality to serve this purpose may not be advantageous as it may convey inaccurate or insufficient information. Multi-modal imaging strategies are becoming more popular for in vivo cellular and molecular imaging because of their improved sensitivity, higher resolution and structural/functional visualization. This study aims at formulating Nile Red doped hexamethyldisiloxane (HMDSO) nanoemulsions as dual modality (Magnetic Resonance Imaging/Fluorescence), dual-functional (oximetry/detection) nanoprobes for cellular and molecular imaging. HMDSO nanoprobes were prepared using a HS15-lecithin combination as surfactant and showed an average radius of 71±39 nm by dynamic light scattering and in vitro particle stability in human plasma over 24 hrs. They were found to readily localize in the cytosol of MCF7-GFP cells within 18 minutes of incubation. As proof of principle, these nanoprobes were successfully used for fluorescence imaging and for measuring pO2 changes in cells by magnetic resonance imaging, in vitro, thus showing potential for in vivo applications. PMID:23382776

Analysis of Students' Aptitude to Provide Meaning to Images that Represent Cellular Components at the Molecular Level

PubMed Central

Dahmani, Hassen-Reda; Schneeberger, Patricia

2009-01-01

The number of experimentally derived structures of cellular components is rapidly expanding, and this phenomenon is accompanied by the development of a new semiotic system for teaching. The infographic approach is shifting from a schematic toward a more realistic representation of cellular components. By realistic we mean artist-prepared or computer graphic images that closely resemble experimentally derived structures and are characterized by a low level of styling and simplification. This change brings about a new challenge for teachers: designing course instructions that allow students to interpret these images in a meaningful way. To determine how students deal with this change, we designed several image-based, in-course assessments. The images were highly relevant for the cell biology course but did not resemble any of the images in the teaching documents. We asked students to label the cellular components, describe their function, or both. What we learned from these tests is that realistic images, with a higher apparent level of complexity, do not deter students from investigating their meaning. When given a choice, the students do not necessarily choose the most simplified representation, and they were sensitive to functional indications embedded in realistic images. PMID:19723817

Magnetic resonance imaging is often misleading when used as an adjunct to ultrasound in the management of placenta accreta spectrum disorders.

PubMed

Einerson, Brett D; Rodriguez, Christina E; Kennedy, Anne M; Woodward, Paula J; Donnelly, Meghan A; Silver, Robert M

2018-06-01

Magnetic resonance imaging is reported to have good sensitivity and specificity in the diagnosis of placenta accreta spectrum disorders, and is often used as an adjunct to ultrasound. But the additional utility of obtaining magnetic resonance imaging to assist in the clinical management of patients with placenta accreta spectrum disorders, above and beyond the information provided by ultrasound, is unknown. We aimed to determine whether magnetic resonance imaging provides data that may inform clinical management by changing the sonographic diagnosis of placenta accreta spectrum disorders. In all, 78 patients with sonographic evidence or clinical suspicion of placenta accreta spectrum underwent magnetic resonance imaging of the abdomen and pelvis in orthogonal planes through the uterus utilizing T1- and T2-weighted imaging sequences at the University of Utah and the University of Colorado from 1997 through 2017. The magnetic resonance imaging was interpreted by radiologists with expertise in diagnosis of placenta accreta spectrum who had knowledge of the sonographic interpretation and clinical risk factors for placenta accreta spectrum disorders. The primary outcome was a change in diagnosis from sonographic interpretation that could alter clinical management, which was defined a priori. Diagnostic accuracy was verified by surgical and histopathologic diagnosis at the time of delivery. A change in diagnosis that could potentially alter clinical management occurred in 28 (36%) cases. Magnetic resonance imaging correctly changed the diagnosis in 15 (19%), and correctly confirmed the diagnosis in 34 (44%), but resulted in an incorrect change in diagnosis in 13 (17%), and an incorrect confirmation of ultrasound diagnosis in 15 (21%). Magnetic resonance imaging was not more likely to change a diagnosis in the 24 cases of posterior and lateral placental location compared to anterior location (33% vs 37%, P = .84). Magnetic resonance imaging resulted in overdiagnosis in 23% and in underdiagnosis in 14% of all cases. When ultrasound suspected severe disease (percreta) in 14 cases, magnetic resonance imaging changed the diagnosis in only 2 cases. Lastly, the proportion of accurate diagnosis with magnetic resonance imaging did not improve over time (61-65%, P = .96 for trend) despite increasing volume and increasing numbers of changed diagnoses. Magnetic resonance imaging resulted in a change in diagnosis that could alter clinical management of placenta accreta spectrum disorders in more than one third of cases, but when changed, the diagnosis was often incorrect. Given its high cost and limited clinical value, magnetic resonance imaging should not be used routinely as an adjunct to ultrasound in the diagnosis of placenta accreta spectrum until evidence for utility is clearly demonstrated by more definitive prospective studies. Copyright © 2018 Elsevier Inc. All rights reserved.

The Research of Spectral Reconstruction for Large Aperture Static Imaging Spectrometer

NASA Astrophysics Data System (ADS)

Lv, H.; Lee, Y.; Liu, R.; Fan, C.; Huang, Y.

2018-04-01

Imaging spectrometer obtains or indirectly obtains the spectral information of the ground surface feature while obtaining the target image, which makes the imaging spectroscopy has a prominent advantage in fine characterization of terrain features, and is of great significance for the study of geoscience and other related disciplines. Since the interference data obtained by interferometric imaging spectrometer is intermediate data, which must be reconstructed to achieve the high quality spectral data and finally used by users. The difficulty to restrict the application of interferometric imaging spectroscopy is to reconstruct the spectrum accurately. Based on the original image acquired by Large Aperture Static Imaging Spectrometer as the input, this experiment selected the pixel that is identified as crop by artificial recognition, extract and preprocess the interferogram to recovery the corresponding spectrum of this pixel. The result shows that the restructured spectrum formed a small crest near the wavelength of 0.55 μm with obvious troughs on both sides. The relative reflection intensity of the restructured spectrum rises abruptly at the wavelength around 0.7 μm, forming a steep slope. All these characteristics are similar with the spectral reflection curve of healthy green plants. It can be concluded that the experimental result is consistent with the visual interpretation results, thus validating the effectiveness of the scheme for interferometric imaging spectrum reconstruction proposed in this paper.

[Restoration filtering based on projection power spectrum for single-photon emission computed tomography].

PubMed

Kubo, N

1995-04-01

To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images.

Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis

PubMed Central

Härmä, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Åkerfelt, Malin; Lötjönen, Jyrki; Nees, Matthias

2014-01-01

Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports the growing needs for user-friendly, straightforward solutions that facilitate large-scale, cell-based 3D assays in basic research, drug discovery, and target validation. PMID:24810913

Ferritin heavy chain as a molecular imaging reporter gene in glioma xenografts.

PubMed

Cheng, Sen; Mi, Ruifang; Xu, Yu; Jin, Guishan; Zhang, Junwen; Zhou, Yiqiang; Chen, Zhengguang; Liu, Fusheng

2017-06-01

The development of glioma therapy in clinical practice (e.g., gene therapy) calls for efficiently visualizing and tracking glioma cells in vivo. Human ferritin heavy chain is a novel gene reporter in magnetic resonance imaging. This study proposes hFTH as a reporter gene for MR molecular imaging in glioma xenografts. Rat C6 glioma cells were infected by packaged lentivirus carrying hFTH and EGFP genes and obtained by fluorescence-activated cell sorting. The iron-loaded ability was analyzed by the total iron reagent kit. Glioma nude mouse models were established subcutaneously and intracranially. Then, in vivo tumor bioluminescence was performed via the IVIS spectrum imaging system. The MR imaging analysis was analyzed on a 7T animal MRI scanner. Finally, the expression of hFTH was analyzed by western blotting and histological analysis. Stable glioma cells carrying hFTH and EGFP reporter genes were successfully obtained. The intracellular iron concentration was increased without impairing the cell proliferation rate. Glioma cells overexpressing hFTH showed significantly decreased signal intensity on T 2 -weighted MRI both in vitro and in vivo. EGFP fluorescent imaging could also be detected in the subcutaneous and intracranial glioma xenografts. Moreover, the expression of the transferritin receptor was significantly increased in glioma cells carrying the hFTH reporter gene. Our study illustrated that hFTH generated cellular MR imaging contrast efficiently in glioma via regulating the expression of transferritin receptor. This might be a useful reporter gene in cell tracking and MR molecular imaging for glioma diagnosis, gene therapy and tumor metastasis.

Microfluidic Imaging Flow Cytometry by Asymmetric-detection Time-stretch Optical Microscopy (ATOM).

PubMed

Tang, Anson H L; Lai, Queenie T K; Chung, Bob M F; Lee, Kelvin C M; Mok, Aaron T Y; Yip, G K; Shum, Anderson H C; Wong, Kenneth K Y; Tsia, Kevin K

2017-06-28

Scaling the number of measurable parameters, which allows for multidimensional data analysis and thus higher-confidence statistical results, has been the main trend in the advanced development of flow cytometry. Notably, adding high-resolution imaging capabilities allows for the complex morphological analysis of cellular/sub-cellular structures. This is not possible with standard flow cytometers. However, it is valuable for advancing our knowledge of cellular functions and can benefit life science research, clinical diagnostics, and environmental monitoring. Incorporating imaging capabilities into flow cytometry compromises the assay throughput, primarily due to the limitations on speed and sensitivity in the camera technologies. To overcome this speed or throughput challenge facing imaging flow cytometry while preserving the image quality, asymmetric-detection time-stretch optical microscopy (ATOM) has been demonstrated to enable high-contrast, single-cell imaging with sub-cellular resolution, at an imaging throughput as high as 100,000 cells/s. Based on the imaging concept of conventional time-stretch imaging, which relies on all-optical image encoding and retrieval through the use of ultrafast broadband laser pulses, ATOM further advances imaging performance by enhancing the image contrast of unlabeled/unstained cells. This is achieved by accessing the phase-gradient information of the cells, which is spectrally encoded into single-shot broadband pulses. Hence, ATOM is particularly advantageous in high-throughput measurements of single-cell morphology and texture - information indicative of cell types, states, and even functions. Ultimately, this could become a powerful imaging flow cytometry platform for the biophysical phenotyping of cells, complementing the current state-of-the-art biochemical-marker-based cellular assay. This work describes a protocol to establish the key modules of an ATOM system (from optical frontend to data processing and visualization backend), as well as the workflow of imaging flow cytometry based on ATOM, using human cells and micro-algae as the examples.

Confocal Microscopy and Molecular-Specific Optical Contrast Agents for the Detection of Oral Neoplasia

PubMed Central

Carlson, Alicia L.; Gillenwater, Ann M.; Williams, Michelle D.; El-Naggar, Adel K.; Richards-Kortum, R. R.

2009-01-01

Using current clinical diagnostic techniques, it is difficult to visualize tumor morphology and architecture at the cellular level, which is necessary for diagnostic localization of pathologic lesions. Optical imaging techniques have the potential to address this clinical need by providing real-time, sub-cellular resolution images. This paper describes the use of dual mode confocal microscopy and optical molecular-specific contrast agents to image tissue architecture, cellular morphology, and sub-cellular molecular features of normal and neoplastic oral tissues. Fresh tissue slices were prepared from 33 biopsies of clinically normal and abnormal oral mucosa obtained from 14 patients. Reflectance confocal images were acquired after the application of 6% acetic acid, and fluorescence confocal images were acquired after the application of a fluorescence contrast agent targeting the epidermal growth factor receptor (EGFR). The dual imaging modes provided images similar to light microscopy of hematoxylin and eosin and immunohistochemistry staining, but from thick fresh tissue slices. Reflectance images provided information on the architecture of the tissue and the cellular morphology. The nuclear-to-cytoplasmic (N/C) ratio from the reflectance images was at least 7.5 times greater for the carcinoma than the corresponding normal samples, except for one case of highly keratinized carcinoma. Separation of carcinoma from normal and mild dysplasia was achieved using this ratio (p<0.01). Fluorescence images of EGFR expression yielded a mean fluorescence labeling intensity (FLI) that was at least 2.7 times higher for severe dysplasia and carcinoma samples than for the corresponding normal sample, and could be used to distinguish carcinoma from normal and mild dysplasia (p<0.01). Analyzed together, the N/C ratio and the mean FLI may improve the ability to distinguish carcinoma from normal squamous epithelium. PMID:17877424

Reduced background autofluorescence for cell imaging using nanodiamonds and lanthanide chelates.

PubMed

Cordina, Nicole M; Sayyadi, Nima; Parker, Lindsay M; Everest-Dass, Arun; Brown, Louise J; Packer, Nicolle H

2018-03-14

Bio-imaging is a key technique in tracking and monitoring important biological processes and fundamental biomolecular interactions, however the interference of background autofluorescence with targeted fluorophores is problematic for many bio-imaging applications. This study reports on two novel methods for reducing interference with cellular autofluorescence for bio-imaging. The first method uses fluorescent nanodiamonds (FNDs), containing nitrogen vacancy centers. FNDs emit at near-infrared wavelengths typically higher than most cellular autofluorescence; and when appropriately functionalized, can be used for background-free imaging of targeted biomolecules. The second method uses europium-chelating tags with long fluorescence lifetimes. These europium-chelating tags enhance background-free imaging due to the short fluorescent lifetimes of cellular autofluorescence. In this study, we used both methods to target E-selectin, a transmembrane glycoprotein that is activated by inflammation, to demonstrate background-free fluorescent staining in fixed endothelial cells. Our findings indicate that both FND and Europium based staining can improve fluorescent bio-imaging capabilities by reducing competition with cellular autofluorescence. 30 nm nanodiamonds coated with the E-selectin antibody was found to enable the most sensitive detective of E-selectin in inflamed cells, with a 40-fold increase in intensity detected.

Survey statistics of automated segmentations applied to optical imaging of mammalian cells.

PubMed

Bajcsy, Peter; Cardone, Antonio; Chalfoun, Joe; Halter, Michael; Juba, Derek; Kociolek, Marcin; Majurski, Michael; Peskin, Adele; Simon, Carl; Simon, Mylene; Vandecreme, Antoine; Brady, Mary

2015-10-15

The goal of this survey paper is to overview cellular measurements using optical microscopy imaging followed by automated image segmentation. The cellular measurements of primary interest are taken from mammalian cells and their components. They are denoted as two- or three-dimensional (2D or 3D) image objects of biological interest. In our applications, such cellular measurements are important for understanding cell phenomena, such as cell counts, cell-scaffold interactions, cell colony growth rates, or cell pluripotency stability, as well as for establishing quality metrics for stem cell therapies. In this context, this survey paper is focused on automated segmentation as a software-based measurement leading to quantitative cellular measurements. We define the scope of this survey and a classification schema first. Next, all found and manually filteredpublications are classified according to the main categories: (1) objects of interests (or objects to be segmented), (2) imaging modalities, (3) digital data axes, (4) segmentation algorithms, (5) segmentation evaluations, (6) computational hardware platforms used for segmentation acceleration, and (7) object (cellular) measurements. Finally, all classified papers are converted programmatically into a set of hyperlinked web pages with occurrence and co-occurrence statistics of assigned categories. The survey paper presents to a reader: (a) the state-of-the-art overview of published papers about automated segmentation applied to optical microscopy imaging of mammalian cells, (b) a classification of segmentation aspects in the context of cell optical imaging, (c) histogram and co-occurrence summary statistics about cellular measurements, segmentations, segmented objects, segmentation evaluations, and the use of computational platforms for accelerating segmentation execution, and (d) open research problems to pursue. The novel contributions of this survey paper are: (1) a new type of classification of cellular measurements and automated segmentation, (2) statistics about the published literature, and (3) a web hyperlinked interface to classification statistics of the surveyed papers at https://isg.nist.gov/deepzoomweb/resources/survey/index.html.

Spectrum Tunable Quantum Dot-In-A-Well Infrared Detector Arrays for Thermal Imaging

DTIC Science & Technology

2008-09-01

Spectrum tunable quantum dot-in-a- well infrared detector arrays for thermal imaging Jonathan R. Andrews1, Sergio R. Restaino1, Scott W. Teare2...Materials at the University of New Mexico has been investigating quantum dot and quantum well detectors for thermal infrared imaging applications...SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Spectrum tunable quantum dot-in-a- well infrared

An authenticated image encryption scheme based on chaotic maps and memory cellular automata

NASA Astrophysics Data System (ADS)

Bakhshandeh, Atieh; Eslami, Ziba

2013-06-01

This paper introduces a new image encryption scheme based on chaotic maps, cellular automata and permutation-diffusion architecture. In the permutation phase, a piecewise linear chaotic map is utilized to confuse the plain-image and in the diffusion phase, we employ the Logistic map as well as a reversible memory cellular automata to obtain an efficient and secure cryptosystem. The proposed method admits advantages such as highly secure diffusion mechanism, computational efficiency and ease of implementation. A novel property of the proposed scheme is its authentication ability which can detect whether the image is tampered during the transmission or not. This is particularly important in applications where image data or part of it contains highly sensitive information. Results of various analyses manifest high security of this new method and its capability for practical image encryption.

Discriminative segmentation of microscopic cellular images.

PubMed

Cheng, Li; Ye, Ning; Yu, Weimiao; Cheah, Andre

2011-01-01

Microscopic cellular images segmentation has become an important routine procedure in modern biological research, due to the rapid advancement of fluorescence probes and robotic microscopes in recent years. In this paper we advocate a discriminative learning approach for cellular image segmentation. In particular, three new features are proposed to capture the appearance, shape and context information, respectively. Experiments are conducted on three different cellular image datasets. Despite the significant disparity among these datasets, the proposed approach is demonstrated to perform reasonably well. As expected, for a particular dataset, some features turn out to be more suitable than others. Interestingly, we observe that a further gain can often be obtained on top of using the "good" features, by also retaining those features that perform poorly. This might be due to the complementary nature of these features, as well as the capacity of our approach to better integrate and exploit different sources of information.

A novel image encryption algorithm using chaos and reversible cellular automata

NASA Astrophysics Data System (ADS)

Wang, Xingyuan; Luan, Dapeng

2013-11-01

In this paper, a novel image encryption scheme is proposed based on reversible cellular automata (RCA) combining chaos. In this algorithm, an intertwining logistic map with complex behavior and periodic boundary reversible cellular automata are used. We split each pixel of image into units of 4 bits, then adopt pseudorandom key stream generated by the intertwining logistic map to permute these units in confusion stage. And in diffusion stage, two-dimensional reversible cellular automata which are discrete dynamical systems are applied to iterate many rounds to achieve diffusion on bit-level, in which we only consider the higher 4 bits in a pixel because the higher 4 bits carry almost the information of an image. Theoretical analysis and experimental results demonstrate the proposed algorithm achieves a high security level and processes good performance against common attacks like differential attack and statistical attack. This algorithm belongs to the class of symmetric systems.

Nanobodies and recombinant binders in cell biology.

PubMed

Helma, Jonas; Cardoso, M Cristina; Muyldermans, Serge; Leonhardt, Heinrich

2015-06-08

Antibodies are key reagents to investigate cellular processes. The development of recombinant antibodies and binders derived from natural protein scaffolds has expanded traditional applications, such as immunofluorescence, binding arrays, and immunoprecipitation. In addition, their small size and high stability in ectopic environments have enabled their use in all areas of cell research, including structural biology, advanced microscopy, and intracellular expression. Understanding these novel reagents as genetic modules that can be integrated into cellular pathways opens up a broad experimental spectrum to monitor and manipulate cellular processes. © 2015 Helma et al.

The application of an optical Fourier spectrum analyzer on detecting defects in mass-produced satellite photographs

NASA Technical Reports Server (NTRS)

Athale, R.; Lee, S. H.

1976-01-01

Various defects in mass-produced pictures transmitted to earth from a satellite are investigated. It is found that the following defects are readily detectable via Fourier spectrum analysis: (1) bit slip, (2) breakup causing loss of image, and (3) disabled track at the top of the imagery. The scratches made on the film during mass production, which are difficult to detect by visual observation, also show themselves readily in Fourier spectrum analysis. A relation is established between the number of scratches, their width and depth and the intensity of their Fourier spectra. Other defects that are found to be equally suitable for Fourier spectrum analysis or visual (image analysis) detection are synchronous loss without blurring of image, and density variation in gray scale. However, the Fourier spectrum analysis is found to be unsuitable for detection of such defects as pin holes, annotation error, synchronous loss with blurring of images, and missing image in the beginning of the work order. The design of an automated, real time system, which will reject defective films, is treated.

Polymeric nanocomposites loaded with fluoridated hydroxyapatite Ln3+ (Ln = Eu or Tb)/iron oxide for magnetic targeted cellular imaging

PubMed Central

Pan, Jie; Liu, Wei-Jiao; Hua, Chao; Wang, Li-Li; Wan, Dong; Gong, Jun-Bo

2015-01-01

Objective To fabricate polymeric nanocomposites with excellent photoluminescence, magnetic properties, and stability in aqueous solutions, in order to improve specificity and sensitivity of cellular imaging under a magnetic field. Methods Fluoridated Ln3+-doped HAP (Ln3+-HAP) NPs and iron oxides (IOs) can be encapsulated with biocompatible polymers via a modified solvent exaction/evaporation technique to prepare polymeric nanocomposites with fluoridated Ln3+-HAP/iron oxide. The nanocomposites were characterized for surface morphology, fluorescence spectra, magnetic properties and in vitro cytotoxicity. Magnetic targeted cellular imaging of such nanocomposites was also evaluated with confocal laser scanning microscope using A549 cells with or without magnetic field. Results The fabricated nanocomposites showed good stability and excellent luminescent properties, as well as low in vitro cytotoxicity, indicating that the nanocomposites are suitable for biological applications. Nanocomposites under magnetic field achieved much higher cellular uptake via an energy-dependent pathway than those without magnetic field. Conclusion The nanocomposites fabricated in this study will be a promising tool for magnetic targeted cellular imaging with improved specificity and enhanced selection. PMID:26487962

Superpixel segmentation and pigment identification of colored relics based on visible spectral image.

PubMed

Li, Junfeng; Wan, Xiaoxia

2018-01-15

To enrich the contents of digital archive and to guide the copy and restoration of colored relics, non-invasive methods for extraction of painting boundary and identification of pigment composition are proposed in this study based on the visible spectral images of colored relics. Superpixel concept is applied for the first time to the field of oversegmentation of visible spectral images and implemented on the visible spectral images of colored relics to extract their painting boundary. Since different pigments are characterized by their own spectrum and the same kind of pigment has the similar geometric profile in spectrum, an automatic identification method is established by comparing the proximity between the geometric profiles of the unknown spectrum from each superpixel and the pre-known spectrum from a deliberately prepared database. The methods are validated using the visible spectral images of the ancient wall paintings in Mogao Grottoes. By the way, the visible spectral images are captured by a multispectral imaging system consisting of two broadband filters and a RGB camera with high spatial resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Smartphone confocal microscopy for imaging cellular structures in human skin in vivo.

PubMed

Freeman, Esther E; Semeere, Aggrey; Osman, Hany; Peterson, Gary; Rajadhyaksha, Milind; González, Salvador; Martin, Jeffery N; Anderson, R Rox; Tearney, Guillermo J; Kang, Dongkyun

2018-04-01

We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging.

Smartphone confocal microscopy for imaging cellular structures in human skin in vivo

PubMed Central

Freeman, Esther E.; Semeere, Aggrey; Osman, Hany; Peterson, Gary; Rajadhyaksha, Milind; González, Salvador; Martin, Jeffery N.; Anderson, R. Rox; Tearney, Guillermo J.; Kang, Dongkyun

2018-01-01

We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging. PMID:29675328

Mapping whole-brain activity with cellular resolution by light-sheet microscopy and high-throughput image analysis (Conference Presentation)

NASA Astrophysics Data System (ADS)

Silvestri, Ludovico; Rudinskiy, Nikita; Paciscopi, Marco; Müllenbroich, Marie Caroline; Costantini, Irene; Sacconi, Leonardo; Frasconi, Paolo; Hyman, Bradley T.; Pavone, Francesco S.

2016-03-01

Mapping neuronal activity patterns across the whole brain with cellular resolution is a challenging task for state-of-the-art imaging methods. Indeed, despite a number of technological efforts, quantitative cellular-resolution activation maps of the whole brain have not yet been obtained. Many techniques are limited by coarse resolution or by a narrow field of view. High-throughput imaging methods, such as light sheet microscopy, can be used to image large specimens with high resolution and in reasonable times. However, the bottleneck is then moved from image acquisition to image analysis, since many TeraBytes of data have to be processed to extract meaningful information. Here, we present a full experimental pipeline to quantify neuronal activity in the entire mouse brain with cellular resolution, based on a combination of genetics, optics and computer science. We used a transgenic mouse strain (Arc-dVenus mouse) in which neurons which have been active in the last hours before brain fixation are fluorescently labelled. Samples were cleared with CLARITY and imaged with a custom-made confocal light sheet microscope. To perform an automatic localization of fluorescent cells on the large images produced, we used a novel computational approach called semantic deconvolution. The combined approach presented here allows quantifying the amount of Arc-expressing neurons throughout the whole mouse brain. When applied to cohorts of mice subject to different stimuli and/or environmental conditions, this method helps finding correlations in activity between different neuronal populations, opening the possibility to infer a sort of brain-wide 'functional connectivity' with cellular resolution.

Quantitative comparison between full-spectrum and filter-based imaging in hyperspectral fluorescence microscopy

PubMed Central

GAO, L.; HAGEN, N.; TKACZYK, T.S.

2012-01-01

Summary We implement a filterless illumination scheme on a hyperspectral fluorescence microscope to achieve full-range spectral imaging. The microscope employs polarisation filtering, spatial filtering and spectral unmixing filtering to replace the role of traditional filters. Quantitative comparisons between full-spectrum and filter-based microscopy are provided in the context of signal dynamic range and accuracy of measured fluorophores’ emission spectra. To show potential applications, a five-colour cell immunofluorescence imaging experiment is theoretically simulated. Simulation results indicate that the use of proposed full-spectrum imaging technique may result in three times improvement in signal dynamic range compared to that can be achieved in the filter-based imaging. PMID:22356127

Simultaneous cathodoluminescence and electron microscopy cytometry of cellular vesicles labeled with fluorescent nanodiamonds.

PubMed

Nagarajan, Sounderya; Pioche-Durieu, Catherine; Tizei, Luiz H G; Fang, Chia-Yi; Bertrand, Jean-Rémi; Le Cam, Eric; Chang, Huan-Cheng; Treussart, François; Kociak, Mathieu

2016-06-02

Light and Transmission Electron Microscopies (LM and TEM) hold potential in bioimaging owing to the advantages of fast imaging of multiple cells with LM and ultrastructure resolution offered by TEM. Integrated or correlated LM and TEM are the current approaches to combine the advantages of both techniques. Here we propose an alternative in which the electron beam of a scanning TEM (STEM) is used to excite concomitantly the luminescence of nanoparticle labels (a process known as cathodoluminescence, CL), and image the cell ultrastructure. This CL-STEM imaging allows obtaining luminescence spectra and imaging ultrastructure simultaneously. We present a proof of principle experiment, showing the potential of this technique in image cytometry of cell vesicular components. To label the vesicles we used fluorescent diamond nanocrystals (nanodiamonds, NDs) of size ≈150 nm coated with different cationic polymers, known to trigger different internalization pathways. Each polymer was associated with a type of ND with a different emission spectrum. With CL-STEM, for each individual vesicle, we were able to measure (i) their size with nanometric resolution, (ii) their content in different ND labels, and realize intracellular component cytometry. In contrast to the recently reported organelle flow cytometry technique that requires cell sonication, CL-STEM-based image cytometry preserves the cell integrity and provides a much higher resolution in size. Although this novel approach is still limited by a low throughput, the automatization of data acquisition and image analysis, combined with improved intracellular targeting, should facilitate applications in cell biology at the subcellular level.

Synapses as therapeutic targets for autism spectrum disorders: an international symposium held in pavia on july 4th, 2014.

PubMed

Curatolo, Paolo; Ben-Ari, Yehezkel; Bozzi, Yuri; Catania, Maria Vincenza; D'Angelo, Egidio; Mapelli, Lisa; Oberman, Lindsay M; Rosenmund, Christian; Cherubini, Enrico

2014-01-01

New progresses into the molecular and cellular mechanisms of autism spectrum disorders (ASDs) have been discussed in 1 day international symposium held in Pavia (Italy) on July 4th, 2014 entitled "synapses as therapeutic targets for autism spectrum disorders" (satellite of the FENS Forum for Neuroscience, Milan, 2014). In particular, world experts in the field have highlighted how animal models of ASDs have greatly advanced our understanding of the molecular pathways involved in synaptic dysfunction leading sometimes to "synaptic clinical trials" in children.

Hypothesis on human eye perceiving optical spectrum rather than an image

NASA Astrophysics Data System (ADS)

Zheng, Yufeng; Szu, Harold

2015-05-01

It is a common knowledge that we see the world because our eyes can perceive an optical image. A digital camera seems a good example of simulating the eye imaging system. However, the signal sensing and imaging on human retina is very complicated. There are at least five layers (of neurons) along the signal pathway: photoreceptors (cones and rods), bipolar, horizontal, amacrine and ganglion cells. To sense an optical image, it seems that photoreceptors (as sensors) plus ganglion cells (converting to electrical signals for transmission) are good enough. Image sensing does not require ununiformed distribution of photoreceptors like fovea. There are some challenging questions, for example, why don't we feel the "blind spots" (never fibers exiting the eyes)? Similar situation happens to glaucoma patients who do not feel their vision loss until 50% or more nerves died. Now our hypothesis is that human retina initially senses optical (i.e., Fourier) spectrum rather than optical image. Due to the symmetric property of Fourier spectrum the signal loss from a blind spot or the dead nerves (for glaucoma patients) can be recovered. Eye logarithmic response to input light intensity much likes displaying Fourier magnitude. The optics and structures of human eyes satisfy the needs of optical Fourier spectrum sampling. It is unsure that where and how inverse Fourier transform is performed in human vision system to obtain an optical image. Phase retrieval technique in compressive sensing domain enables image reconstruction even without phase inputs. The spectrum-based imaging system can potentially tolerate up to 50% of bad sensors (pixels), adapt to large dynamic range (with logarithmic response), etc.

Label-Free Analysis of Cellular Lipid Droplet Formation by Non-Linear Microscopy

NASA Astrophysics Data System (ADS)

Schie, Iwan W.

Cellular lipid droplets (LD) are cellular organelles that can be found in every cell type. Recent research indicates that cellular LD are involved in a large number of cellular metabolic functions, such as lipid metabolism, protection from lipotoxicity, protein storage and degradation, and many more. LD formation is frequently associated with adverse health effects, i.e. alcoholic and non-alcoholic fatty liver disease, diabetes type-2, as well as many cardiovascular disorders. Despite their wide presence, LDs are the least studied and most poorly understood cellular organelles. Typically, LDs are investigated using fluorescence-based techniques that require staining with exogenous fluorophores. Other techniques, e.g. biochemical assays, require the destruction of cells that prohibit the analysis of living cells. Therefore, in my thesis research I developed a novel compound fast-scanning nonlinear optical microscope equipped with the ability to also acquire Raman spectra at specific image locations. This system allows us to image label-free cellular LD formation in living cells and analyze the composition of single cellular LDs. Images can be acquired at near video-rate (˜16 frames/s). Furthermore, the system has the ability to acquire very large images of tissue of up to 7.5x15 cm2 total area by stitching together scans with dimensions of 1x1 mm2 in less than 1 minute. The system also enables the user to acquire Raman spectra from points of interest in the multiphoton images and provides chemically-specific data from sample volumes as small as 1 femtoliter. In my thesis I used this setup to determine the effects of VLDL lipolysis products on primary rat hepatocytes. By analyzing the Raman spectra and comparing the peak ratios for saturated and unsaturated fatty acid it was determined that the small cellular LD are highly saturated, while large cellular LDs contain mostly unsaturated lipids. Furthermore, I established a method to determine the specific contribution of each individual fatty acids to a single cellular LD based on non-negative least squares analysis. The calculated quantities for oleic and palmitic acid from 10 individual cellular LDs were compared to results of a gas chromatography (GC) analysis of 2x10 6 cells. The analysis found that the data obtained by Raman spectroscopy of individual LDs closely resemble GC data of a significantly larger number of LDs.

Live-cell imaging.

PubMed

Cole, Richard

2014-01-01

It would be hard to argue that live-cell imaging has not changed our view of biology. The past 10 years have seen an explosion of interest in imaging cellular processes, down to the molecular level. There are now many advanced techniques being applied to live cell imaging. However, cellular health is often under appreciated. For many researchers, if the cell at the end of the experiment has not gone into apoptosis or is blebbed beyond recognition, than all is well. This is simply incorrect. There are many factors that need to be considered when performing live-cell imaging in order to maintain cellular health such as: imaging modality, media, temperature, humidity, PH, osmolality, and photon dose. The wavelength of illuminating light, and the total photon dose that the cells are exposed to, comprise two of the most important and controllable parameters of live-cell imaging. The lowest photon dose that achieves a measureable metric for the experimental question should be used, not the dose that produces cover photo quality images. This is paramount to ensure that the cellular processes being investigated are in their in vitro state and not shifted to an alternate pathway due to environmental stress. The timing of the mitosis is an ideal canary in the gold mine, in that any stress induced from the imaging will result in the increased length of mitosis, thus providing a control model for the current imagining conditions.

Live-cell imaging

PubMed Central

Cole, Richard

2014-01-01

It would be hard to argue that live-cell imaging has not changed our view of biology. The past 10 years have seen an explosion of interest in imaging cellular processes, down to the molecular level. There are now many advanced techniques being applied to live cell imaging. However, cellular health is often under appreciated. For many researchers, if the cell at the end of the experiment has not gone into apoptosis or is blebbed beyond recognition, than all is well. This is simply incorrect. There are many factors that need to be considered when performing live-cell imaging in order to maintain cellular health such as: imaging modality, media, temperature, humidity, PH, osmolality, and photon dose. The wavelength of illuminating light, and the total photon dose that the cells are exposed to, comprise two of the most important and controllable parameters of live-cell imaging. The lowest photon dose that achieves a measureable metric for the experimental question should be used, not the dose that produces cover photo quality images. This is paramount to ensure that the cellular processes being investigated are in their in vitro state and not shifted to an alternate pathway due to environmental stress. The timing of the mitosis is an ideal canary in the gold mine, in that any stress induced from the imaging will result in the increased length of mitosis, thus providing a control model for the current imagining conditions. PMID:25482523

Spread-Spectrum Beamforming and Clutter Filtering for Plane-Wave Color Doppler Imaging.

PubMed

Mansour, Omar; Poepping, Tamie L; Lacefield, James C

2016-07-21

Plane-wave imaging is desirable for its ability to achieve high frame rates, allowing the capture of fast dynamic events and continuous Doppler data. In most implementations of plane-wave imaging, multiple low-resolution images from different plane wave tilt angles are compounded to form a single high-resolution image, thereby reducing the frame rate. Compounding improves the lateral beam profile in the high-resolution image, but it also acts as a low-pass filter in slow time that causes attenuation and aliasing of signals with high Doppler shifts. This paper introduces a spread-spectrum color Doppler imaging method that produces high-resolution images without the use of compounding, thereby eliminating the tradeoff between beam quality, maximum unaliased Doppler frequency, and frame rate. The method uses a long, random sequence of transmit angles rather than a linear sweep of plane wave directions. The random angle sequence randomizes the phase of off-focus (clutter) signals, thereby spreading the clutter power in the Doppler spectrum, while keeping the spectrum of the in-focus signal intact. The ensemble of randomly tilted low-resolution frames also acts as the Doppler ensemble, so it can be much longer than a conventional linear sweep, thereby improving beam formation while also making the slow-time Doppler sampling frequency equal to the pulse repetition frequency. Experiments performed using a carotid artery phantom with constant flow demonstrate that the spread-spectrum method more accurately measures the parabolic flow profile of the vessel and outperforms conventional plane-wave Doppler in both contrast resolution and estimation of high flow velocities. The spread-spectrum method is expected to be valuable for Doppler applications that require measurement of high velocities at high frame rates.

Neoplastic stomach lesions and their mimickers: spectrum of imaging manifestations

PubMed Central

Virmani, Vivek; Sethi, Vineeta; Fraser-Hill, Margret; Fasih, Najla; Kielar, Ania

2012-01-01

Abstract This review illustrates a wide spectrum of gastric neoplasms with emphasis on imaging findings helpful in characterizing various gastric neoplasms. Both the malignant and benign neoplasms along with focal gastric masses mimicking tumour are illustrated. Moreover, imaging clues to reach an accurate diagnosis are emphasized. PMID:22935192

Adaptive technique for matching the spectral response in skin lesions' images

NASA Astrophysics Data System (ADS)

Pavlova, P.; Borisova, E.; Pavlova, E.; Avramov, L.

2015-03-01

The suggested technique is a subsequent stage for data obtaining from diffuse reflectance spectra and images of diseased tissue with a final aim of skin cancer diagnostics. Our previous work allows us to extract patterns for some types of skin cancer, as a ratio between spectra, obtained from healthy and diseased tissue in the range of 380 - 780 nm region. The authenticity of the patterns depends on the tested point into the area of lesion, and the resulting diagnose could also be fixed with some probability. In this work, two adaptations are implemented to localize pixels of the image lesion, where the reflectance spectrum corresponds to pattern. First adapts the standard to the personal patient and second - translates the spectrum white point basis to the relative white point of the image. Since the reflectance spectra and the image pixels are regarding to different white points, a correction of the compared colours is needed. The latest is done using a standard method for chromatic adaptation. The technique follows the steps below: -Calculation the colorimetric XYZ parameters for the initial white point, fixed by reflectance spectrum from healthy tissue; -Calculation the XYZ parameters for the distant white point on the base of image of nondiseased tissue; -Transformation the XYZ parameters for the test-spectrum by obtained matrix; -Finding the RGB values of the XYZ parameters for the test-spectrum according sRGB; Finally, the pixels of the lesion's image, corresponding to colour from the test-spectrum and particular diagnostic pattern are marked with a specific colour.

Discovery of a New Cellular Motion and Its Relevance to Breast Cancer and Involution

DTIC Science & Technology

2014-02-01

motion (CAMo), live cell imaging , confocal microscopy Overall Project Summary: During this first year of funding we have concentrated our work to...cell types in 3D cultures and in vivo. Subtask 1.1a: Real time live cell imaging using confocal microscopy will be used to image cellular movement...exciting as they are important steps in understanding behavior of normal myoepithelial cells using live cell imaging in physiologically

Simultaneous imaging of cellular morphology and multiple biomarkers using an acousto-optic tunable filter-based bright field microscope.

PubMed

Wachman, Elliot S; Geyer, Stanley J; Recht, Joel M; Ward, Jon; Zhang, Bill; Reed, Murray; Pannell, Chris

2014-05-01

An acousto-optic tunable filter (AOTF)-based multispectral imaging microscope system allows the combination of cellular morphology and multiple biomarker stainings on a single microscope slide. We describe advances in AOTF technology that have greatly improved spectral purity, field uniformity, and image quality. A multispectral imaging bright field microscope using these advances demonstrates pathology results that have great potential for clinical use.

Measuring spatial and temporal Ca2+ signals in Arabidopsis plants.

PubMed

Zhu, Xiaohong; Taylor, Aaron; Zhang, Shenyu; Zhang, Dayong; Feng, Ying; Liang, Gaimei; Zhu, Jian-Kang

2014-09-02

Developmental and environmental cues induce Ca(2+) fluctuations in plant cells. Stimulus-specific spatial-temporal Ca(2+) patterns are sensed by cellular Ca(2+) binding proteins that initiate Ca(2+) signaling cascades. However, we still know little about how stimulus specific Ca(2+) signals are generated. The specificity of a Ca(2+) signal may be attributed to the sophisticated regulation of the activities of Ca(2+) channels and/or transporters in response to a given stimulus. To identify these cellular components and understand their functions, it is crucial to use systems that allow a sensitive and robust recording of Ca(2+) signals at both the tissue and cellular levels. Genetically encoded Ca(2+) indicators that are targeted to different cellular compartments have provided a platform for live cell confocal imaging of cellular Ca(2+) signals. Here we describe instructions for the use of two Ca(2+) detection systems: aequorin based FAS (film adhesive seedlings) luminescence Ca(2+) imaging and case12 based live cell confocal fluorescence Ca(2+) imaging. Luminescence imaging using the FAS system provides a simple, robust and sensitive detection of spatial and temporal Ca(2+) signals at the tissue level, while live cell confocal imaging using Case12 provides simultaneous detection of cytosolic and nuclear Ca(2+) signals at a high resolution.

Magnetic resonance imaging findings of cellular angiofibroma of the tunica vaginalis of the testis: a case report.

PubMed

Ntorkou, Alexandra A; Tsili, Athina C; Giannakis, Dimitrios; Batistatou, Anna; Stavrou, Sotirios; Sofikitis, Nikolaos; Argyropoulou, Maria I

2016-03-31

Cellular angiofibroma represents a rare mesenchymal tumor typically involving the inguinoscrotal area in middle-aged men. Although the origin of this benign tumor is unknown, it is histologically classified as an angiomyxoid tumor. Cellular angiofibroma is characterized by a diversity of pathological and imaging features. An accurate preoperative diagnosis is challenging. Magnetic resonance imaging examination of the scrotum has been reported as a valuable adjunct modality in the investigation of scrotal pathology. The technique by providing both structural and functional information is useful in the differentiation between extratesticular and intratesticular diseases and in the preoperative characterization of the histologic nature of various scrotal lesions. There are few reports in the English literature addressing the magnetic resonance imaging findings of cellular angiofibroma of the scrotum and no reports on functional magnetic resonance imaging data. Here we present the first case of a cellular angiofibroma arising from the tunica vaginalis of the testis and we discuss the value of a multiparametric magnetic resonance protocol, including diffusion-weighted imaging, magnetization transfer imaging and dynamic contrast-enhanced magnetic resonance imaging in the preoperative diagnosis of this rare neoplasm. A 47-year Greek man presented with a painless left scrotal swelling, which had gradually enlarged during the last 6 months. Magnetic resonance imaging of his scrotum displayed a left paratesticular mass, in close proximity to the tunica vaginalis, with heterogeneous high signal intensity on T2-weighted images and no areas of restricted diffusion. The tumor was hypointense on magnetization transfer images, suggestive for the presence of macromolecules. On dynamic contrast-enhanced magnetic resonance imaging the mass showed intense heterogeneous enhancement with a type II curve. Magnetic resonance imaging findings were strongly suggestive of a benign paratesticular tumor, which was confirmed on pathology following lesion excision. Magnetic resonance imaging of the scrotum by combining conventional and functional magnetic resonance data provides useful diagnostic information in the preoperative characterization of scrotal masses. A possible diagnosis of a benign paratesticular tumor based on magnetic resonance imaging features may improve patient care and decrease the number of unnecessary radical surgical explorations.

Cellular neural network-based hybrid approach toward automatic image registration

NASA Astrophysics Data System (ADS)

Arun, Pattathal VijayaKumar; Katiyar, Sunil Kumar

2013-01-01

Image registration is a key component of various image processing operations that involve the analysis of different image data sets. Automatic image registration domains have witnessed the application of many intelligent methodologies over the past decade; however, inability to properly model object shape as well as contextual information has limited the attainable accuracy. A framework for accurate feature shape modeling and adaptive resampling using advanced techniques such as vector machines, cellular neural network (CNN), scale invariant feature transform (SIFT), coreset, and cellular automata is proposed. CNN has been found to be effective in improving feature matching as well as resampling stages of registration and complexity of the approach has been considerably reduced using coreset optimization. The salient features of this work are cellular neural network approach-based SIFT feature point optimization, adaptive resampling, and intelligent object modelling. Developed methodology has been compared with contemporary methods using different statistical measures. Investigations over various satellite images revealed that considerable success was achieved with the approach. This system has dynamically used spectral and spatial information for representing contextual knowledge using CNN-prolog approach. This methodology is also illustrated to be effective in providing intelligent interpretation and adaptive resampling.

Cellular reprogramming: a novel tool for investigating autism spectrum disorders.

PubMed

Kim, Kun-Yong; Jung, Yong Wook; Sullivan, Gareth J; Chung, Leeyup; Park, In-Hyun

2012-08-01

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in reciprocal social interaction and communication, as well as the manifestation of stereotyped behaviors. Despite much effort, ASDs are not yet fully understood. Advanced genetics and genomics technologies have recently identified novel ASD genes, and approaches using genetically engineered murine models or postmortem human brain have facilitated understanding ASD. Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) provides unprecedented opportunities in generating human disease models. Here, we present an overview of applying iPSCs in developing cellular models for understanding ASD. We also discuss future perspectives in the use of iPSCs as a source of cell therapy and as a screening platform for identifying small molecules with efficacy for alleviating ASD. Copyright © 2012. Published by Elsevier Ltd.

Performance of cellular frequency-hopped spread-spectrum radio networks

NASA Astrophysics Data System (ADS)

Gluck, Jeffrey W.; Geraniotis, Evaggelos

1989-10-01

Multiple access interference is characterized for cellular mobile networks, in which users are assumed to be Poisson-distributed in the plane and employ frequency-hopped spread-spectrum signaling with transmitter-oriented assignment of frequency-hopping patterns. Exact expressions for the bit error probabilities are derived for binary coherently demodulated systems without coding. Approximations for the packet error probability are derived for coherent and noncoherent systems and these approximations are applied when forward-error-control coding is employed. In all cases, the effects of varying interference power are accurately taken into account according to some propagation law. Numerical results are given in terms of bit error probability for the exact case and throughput for the approximate analyses. Comparisons are made with previously derived bounds and it is shown that these tend to be very pessimistic.

Achieving Efficient Spectrum Usage in Passive and Active Sensing

NASA Astrophysics Data System (ADS)

Wang, Huaiyi

Increasing demand for supporting more wireless services with higher performance and reliability within the frequency bands that are most conducive to operating cost-effective cellular and mobile broadband is aggravating current electromagnetic spectrum congestion. This situation motivates technology and management innovation to increase the efficiency of spectral use. If primary-secondary spectrum sharing can be shown possible without compromising (or while even improving) performance in an existing application, opportunities for efficiency may be realizable by making the freed spectrum available for commercial use. While both active and passive sensing systems are vitally important for many public good applications, opportunities for increasing the efficiency of spectrum use can be shown to exist for both systems. This dissertation explores methods and technologies for remote sensing systems that enhance spectral efficiency and enable dynamic spectrum access both within and outside traditionally allocated bands.

Automated processing of label-free Raman microscope images of macrophage cells with standardized regression for high-throughput analysis.

PubMed

Milewski, Robert J; Kumagai, Yutaro; Fujita, Katsumasa; Standley, Daron M; Smith, Nicholas I

2010-11-19

Macrophages represent the front lines of our immune system; they recognize and engulf pathogens or foreign particles thus initiating the immune response. Imaging macrophages presents unique challenges, as most optical techniques require labeling or staining of the cellular compartments in order to resolve organelles, and such stains or labels have the potential to perturb the cell, particularly in cases where incomplete information exists regarding the precise cellular reaction under observation. Label-free imaging techniques such as Raman microscopy are thus valuable tools for studying the transformations that occur in immune cells upon activation, both on the molecular and organelle levels. Due to extremely low signal levels, however, Raman microscopy requires sophisticated image processing techniques for noise reduction and signal extraction. To date, efficient, automated algorithms for resolving sub-cellular features in noisy, multi-dimensional image sets have not been explored extensively. We show that hybrid z-score normalization and standard regression (Z-LSR) can highlight the spectral differences within the cell and provide image contrast dependent on spectral content. In contrast to typical Raman imaging processing methods using multivariate analysis, such as single value decomposition (SVD), our implementation of the Z-LSR method can operate nearly in real-time. In spite of its computational simplicity, Z-LSR can automatically remove background and bias in the signal, improve the resolution of spatially distributed spectral differences and enable sub-cellular features to be resolved in Raman microscopy images of mouse macrophage cells. Significantly, the Z-LSR processed images automatically exhibited subcellular architectures whereas SVD, in general, requires human assistance in selecting the components of interest. The computational efficiency of Z-LSR enables automated resolution of sub-cellular features in large Raman microscopy data sets without compromise in image quality or information loss in associated spectra. These results motivate further use of label free microscopy techniques in real-time imaging of live immune cells.

Time-resolved spectroscopic imaging reveals the fundamentals of cellular NADH fluorescence.

PubMed

Li, Dong; Zheng, Wei; Qu, Jianan Y

2008-10-15

A time-resolved spectroscopic imaging system is built to study the fluorescence characteristics of nicotinamide adenine dinucleotide (NADH), an important metabolic coenzyme and endogenous fluorophore in cells. The system provides a unique approach to measure fluorescence signals in different cellular organelles and cytoplasm. The ratios of free over protein-bound NADH signals in cytosol and nucleus are slightly higher than those in mitochondria. The mitochondrial fluorescence contributes about 70% of overall cellular fluorescence and is not a completely dominant signal. Furthermore, NADH signals in mitochondria, cytosol, and the nucleus respond to the changes of cellular activity differently, suggesting that cytosolic and nuclear fluorescence may complicate the well-known relationship between mitochondrial fluorescence and cellular metabolism.

Modification of measurement methods for evaluation of tissue-engineered cartilage function and biochemical properties using nanosecond pulsed laser

NASA Astrophysics Data System (ADS)

Ishihara, Miya; Sato, Masato; Kutsuna, Toshiharu; Ishihara, Masayuki; Mochida, Joji; Kikuchi, Makoto

2008-02-01

There is a demand in the field of regenerative medicine for measurement technology that enables determination of functions and components of engineered tissue. To meet this demand, we developed a method for extracellular matrix characterization using time-resolved autofluorescence spectroscopy, which enabled simultaneous measurements with mechanical properties using relaxation of laser-induced stress wave. In this study, in addition to time-resolved fluorescent spectroscopy, hyperspectral sensor, which enables to capture both spectral and spatial information, was used for evaluation of biochemical characterization of tissue-engineered cartilage. Hyperspectral imaging system provides spectral resolution of 1.2 nm and image rate of 100 images/sec. The imaging system consisted of the hyperspectral sensor, a scanner for x-y plane imaging, magnifying optics and Xenon lamp for transmmissive lighting. Cellular imaging using the hyperspectral image system has been achieved by improvement in spatial resolution up to 9 micrometer. The spectroscopic cellular imaging could be observed using cultured chondrocytes as sample. At early stage of culture, the hyperspectral imaging offered information about cellular function associated with endogeneous fluorescent biomolecules.

Imaging deep skeletal muscle structure using a high-sensitivity ultrathin side-viewing optical coherence tomography needle probe

PubMed Central

Yang, Xiaojie; Lorenser, Dirk; McLaughlin, Robert A.; Kirk, Rodney W.; Edmond, Matthew; Simpson, M. Cather; Grounds, Miranda D.; Sampson, David D.

2013-01-01

We have developed an extremely miniaturized optical coherence tomography (OCT) needle probe (outer diameter 310 µm) with high sensitivity (108 dB) to enable minimally invasive imaging of cellular structure deep within skeletal muscle. Three-dimensional volumetric images were acquired from ex vivo mouse tissue, examining both healthy and pathological dystrophic muscle. Individual myofibers were visualized as striations in the images. Degradation of cellular structure in necrotic regions was seen as a loss of these striations. Tendon and connective tissue were also visualized. The observed structures were validated against co-registered hematoxylin and eosin (H&E) histology sections. These images of internal cellular structure of skeletal muscle acquired with an OCT needle probe demonstrate the potential of this technique to visualize structure at the microscopic level deep in biological tissue in situ. PMID:24466482

Profiling pleural effusion cells by a diffraction imaging method

NASA Astrophysics Data System (ADS)

Al-Qaysi, Safaa; Hong, Heng; Wen, Yuhua; Lu, Jun Q.; Feng, Yuanming; Hu, Xin-Hua

2018-02-01

Assay of cells in pleural effusion (PE) is an important means of disease diagnosis. Conventional cytology of effusion samples, however, has low sensitivity and depends heavily on the expertise of cytopathologists. We applied a polarization diffraction imaging flow cytometry method on effusion cells to investigate their features. Diffraction imaging of the PE cell samples has been performed on 6000 to 12000 cells for each effusion cell sample of three patients. After prescreening to remove images by cellular debris and aggregated non-cellular particles, the image textures were extracted with a gray level co-occurrence matrix (GLCM) algorithm. The distribution of the imaged cells in the GLCM parameters space was analyzed by a Gaussian Mixture Model (GMM) to determine the number of clusters among the effusion cells. These results yield insight on textural features of diffraction images and related cellular morphology in effusion samples and can be used toward the development of a label-free method for effusion cells assay.

Intelligent Interfaces for Mining Large-Scale RNAi-HCS Image Databases

PubMed Central

Lin, Chen; Mak, Wayne; Hong, Pengyu; Sepp, Katharine; Perrimon, Norbert

2010-01-01

Recently, High-content screening (HCS) has been combined with RNA interference (RNAi) to become an essential image-based high-throughput method for studying genes and biological networks through RNAi-induced cellular phenotype analyses. However, a genome-wide RNAi-HCS screen typically generates tens of thousands of images, most of which remain uncategorized due to the inadequacies of existing HCS image analysis tools. Until now, it still requires highly trained scientists to browse a prohibitively large RNAi-HCS image database and produce only a handful of qualitative results regarding cellular morphological phenotypes. For this reason we have developed intelligent interfaces to facilitate the application of the HCS technology in biomedical research. Our new interfaces empower biologists with computational power not only to effectively and efficiently explore large-scale RNAi-HCS image databases, but also to apply their knowledge and experience to interactive mining of cellular phenotypes using Content-Based Image Retrieval (CBIR) with Relevance Feedback (RF) techniques. PMID:21278820

MOVING BEYOND COLOR: THE CASE FOR MULTISPECTRAL IMAGING IN BRIGHTFIELD PATHOLOGY.

PubMed

Cukierski, William J; Qi, Xin; Foran, David J

2009-01-01

A multispectral camera is capable of imaging a histologic slide at narrow bandwidths over the range of the visible spectrum. While several uses for multispectral imaging (MSI) have been demonstrated in pathology [1, 2], there is no unified consensus over when and how MSI might benefit automated analysis [3, 4]. In this work, we use a linear-algebra framework to investigate the relationship between the spectral image and its standard-image counterpart. The multispectral "cube" is treated as an extension of a traditional image in a high-dimensional color space. The concept of metamers is introduced and used to derive regions of the visible spectrum where MSI may provide an advantage. Furthermore, histological stains which are amenable to analysis by MSI are reported. We show the Commission internationale de l'éclairage (CIE) 1931 transformation from spectrum to color is non-neighborhood preserving. Empirical results are demonstrated on multispectral images of peripheral blood smears.

Factors associated with success of image-guided tumour biopsies: Results from a prospective molecular triage study (MOSCATO-01).

PubMed

Tacher, Vania; Le Deley, Marie-Cécile; Hollebecque, Antoine; Deschamps, Frederic; Vielh, Philippe; Hakime, Antoine; Ileana, Ecaterina; Abedi-Ardekani, Behnoush; Charpy, Cécile; Massard, Christophe; Rosellini, Silvia; Gajda, Dorota; Celebic, Aljosa; Ferté, Charles; Ngo-Camus, Maud; Gouissem, Siham; Koubi-Pick, Valérie; Andre, Fabrice; Vassal, Gilles; Deandreis, Désirée; Lacroix, Ludovic; Soria, Jean-Charles; De Baère, Thierry

2016-05-01

MOSCATO-01 is a molecular triage trial based on on-purpose tumour biopsies to perform molecular portraits. We aimed at identifying factors associated with high tumour cellularity. Tumour cellularity (percentage of tumour cells in samples defined at pathology) was evaluated according to patient characteristics, target lesion characteristics, operators' experience and biopsy approach. Among 460 patients enrolled between November, 2011 and March, 2014, 334 patients (73%) had an image-guided needle biopsy of the primary tumour (N = 38) or a metastatic lesion (N = 296). Biopsies were performed on liver (N = 127), lung (N = 72), lymph nodes (N = 71), bone (N = 11), or another tumour site (N = 53). Eighteen patients (5%) experienced a complication: pneumothorax in 10 patients treated medically, and haemorrhage in 8, requiring embolisation in 3 cases. Median tumour cellularity was 50% (interquartile range, 30-70%). The molecular analysis was successful in 291/334 cases (87%). On-going chemotherapy, tumour origin (primary versus metastatic), lesion size, tumour growth rate, presence of necrosis on imaging, standardised uptake value, and needle size were not statistically associated with cellularity. Compared to liver or lung biopsies, cellularity was significantly lower in bone and higher in other sites (P < 0.0001). Cellularity significantly increased with the number of collected samples (P < 0.0001) and was higher in contrast-enhanced ultrasound-guided biopsies (P < 0.02). In paired samples, cellularity in central samples was lower than in peripheral samples in 85, equal in 68 and higher in 89 of the cases. Image-guided biopsy is feasible and safe in cancer patients for molecular screening. Imaging modality, multiple sampling of the lesion, and the organ chosen for biopsy were associated with higher tumour cellularity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genomic copy number analysis of a spectrum of blue nevi identifies recurrent aberrations of entire chromosomal arms in melanoma ex blue nevus.

PubMed

Chan, May P; Andea, Aleodor A; Harms, Paul W; Durham, Alison B; Patel, Rajiv M; Wang, Min; Robichaud, Patrick; Fisher, Gary J; Johnson, Timothy M; Fullen, Douglas R

2016-03-01

Blue nevi may display significant atypia or undergo malignant transformation. Morphologic diagnosis of this spectrum of lesions is notoriously difficult, and molecular tools are increasingly used to improve diagnostic accuracy. We studied copy number aberrations in a cohort of cellular blue nevi, atypical cellular blue nevi, and melanomas ex blue nevi using Affymetrix's OncoScan platform. Cases with sufficient DNA were analyzed for GNAQ, GNA11, and HRAS mutations. Copy number aberrations were detected in 0 of 5 (0%) cellular blue nevi, 3 of 12 (25%) atypical cellular blue nevi, and 6 of 9 (67%) melanomas ex blue nevi. None of the atypical cellular blue nevi displayed more than one aberration, whereas complex aberrations involving four or more regions were seen exclusively in melanomas ex blue nevi. Gains and losses of entire chromosomal arms were identified in four of five melanomas ex blue nevi with copy number aberrations. In particular, gains of 1q, 4p, 6p, and 8q, and losses of 1p and 4q were each found in at least two melanomas. Whole chromosome aberrations were also common, and represented the sole finding in one atypical cellular blue nevus. When seen in melanomas, however, whole chromosome aberrations were invariably accompanied by partial aberrations of other chromosomes. Three melanomas ex blue nevi harbored aberrations, which were absent or negligible in their precursor components, suggesting progression in tumor biology. Gene mutations involving GNAQ and GNA11 were each detected in two of eight melanomas ex blue nevi. In conclusion, copy number aberrations are more common and often complex in melanomas ex blue nevi compared with cellular and atypical cellular blue nevi. Identification of recurrent gains and losses of entire chromosomal arms in melanomas ex blue nevi suggests that development of new probes targeting these regions may improve detection and risk stratification of these lesions.

Cellular and synaptic network defects in autism

PubMed Central

Peça, João; Feng, Guoping

2012-01-01

Many candidate genes are now thought to confer susceptibility to autism spectrum disorder (ASD). Here we review four interrelated complexes, each composed of multiple families of genes that functionally coalesce on common cellular pathways. We illustrate a common thread in the organization of glutamatergic synapses and suggest a link between genes involved in Tuberous Sclerosis Complex, Fragile X syndrome, Angelman syndrome and several synaptic ASD candidate genes. When viewed in this context, progress in deciphering the molecular architecture of cellular protein-protein interactions together with the unraveling of synaptic dysfunction in neural networks may prove pivotal to advancing our understanding of ASDs. PMID:22440525

Advances in high-resolution imaging--techniques for three-dimensional imaging of cellular structures.

PubMed

Lidke, Diane S; Lidke, Keith A

2012-06-01

A fundamental goal in biology is to determine how cellular organization is coupled to function. To achieve this goal, a better understanding of organelle composition and structure is needed. Although visualization of cellular organelles using fluorescence or electron microscopy (EM) has become a common tool for the cell biologist, recent advances are providing a clearer picture of the cell than ever before. In particular, advanced light-microscopy techniques are achieving resolutions below the diffraction limit and EM tomography provides high-resolution three-dimensional (3D) images of cellular structures. The ability to perform both fluorescence and electron microscopy on the same sample (correlative light and electron microscopy, CLEM) makes it possible to identify where a fluorescently labeled protein is located with respect to organelle structures visualized by EM. Here, we review the current state of the art in 3D biological imaging techniques with a focus on recent advances in electron microscopy and fluorescence super-resolution techniques.

High-Throughput Method for Automated Colony and Cell Counting by Digital Image Analysis Based on Edge Detection

PubMed Central

Choudhry, Priya

2016-01-01

Counting cells and colonies is an integral part of high-throughput screens and quantitative cellular assays. Due to its subjective and time-intensive nature, manual counting has hindered the adoption of cellular assays such as tumor spheroid formation in high-throughput screens. The objective of this study was to develop an automated method for quick and reliable counting of cells and colonies from digital images. For this purpose, I developed an ImageJ macro Cell Colony Edge and a CellProfiler Pipeline Cell Colony Counting, and compared them to other open-source digital methods and manual counts. The ImageJ macro Cell Colony Edge is valuable in counting cells and colonies, and measuring their area, volume, morphology, and intensity. In this study, I demonstrate that Cell Colony Edge is superior to other open-source methods, in speed, accuracy and applicability to diverse cellular assays. It can fulfill the need to automate colony/cell counting in high-throughput screens, colony forming assays, and cellular assays. PMID:26848849

3D visualization of subcellular structures of Schizosaccharomyces pombe by hard X-ray tomography.

PubMed

Yang, Y; Li, W; Liu, G; Zhang, X; Chen, J; Wu, W; Guan, Y; Xiong, Y; Tian, Y; Wu, Z

2010-10-01

Cellular structures of the fission yeast, Schizosaccharomyces pombe, were examined by using hard X-ray tomography. Since cells are nearly transparent to hard X-rays, Zernike phase contrast and heavy metal staining were introduced to improve image contrast. Through using such methods, images taken at 8 keV displayed sufficient contrast for observing cellular structures. The cell wall, the intracellular organelles and the entire structural organization of the whole cells were visualized in three-dimensional at a resolution better than 100 nm. Comparison between phase contrast and absorption contrast was also made, indicating the obvious advantage of phase contrast for cellular imaging at this energy. Our results demonstrate that hard X-ray tomography with Zernike phase contrast is suitable for cellular imaging. Its unique abilities make it have potential to become a useful tool for revealing structural information from cells, especially thick eukaryotic cells. © 2010 The Authors Journal compilation © 2010 The Royal Microscopical Society.

High-throughput microscopy must re-invent the microscope rather than speed up its functions

PubMed Central

Oheim, M

2007-01-01

Knowledge gained from the revolutions in genomics and proteomics has helped to identify many of the key molecules involved in cellular signalling. Researchers, both in academia and in the pharmaceutical industry, now screen, at a sub-cellular level, where and when these proteins interact. Fluorescence imaging and molecular labelling combine to provide a powerful tool for real-time functional biochemistry with molecular resolution. However, they traditionally have been work-intensive, required trained personnel, and suffered from low through-put due to sample preparation, loading and handling. The need for speeding up microscopy is apparent from the tremendous complexity of cellular signalling pathways, the inherent biological variability, as well as the possibility that the same molecule plays different roles in different sub-cellular compartments. Research institutes and companies have teamed up to develop imaging cytometers of ever-increasing complexity. However, to truly go high-speed, sub-cellular imaging must free itself from the rigid framework of current microscopes. PMID:17603553

Cell Motility Dynamics: A Novel Segmentation Algorithm to Quantify Multi-Cellular Bright Field Microscopy Images

PubMed Central

Zaritsky, Assaf; Natan, Sari; Horev, Judith; Hecht, Inbal; Wolf, Lior; Ben-Jacob, Eshel; Tsarfaty, Ilan

2011-01-01

Confocal microscopy analysis of fluorescence and morphology is becoming the standard tool in cell biology and molecular imaging. Accurate quantification algorithms are required to enhance the understanding of different biological phenomena. We present a novel approach based on image-segmentation of multi-cellular regions in bright field images demonstrating enhanced quantitative analyses and better understanding of cell motility. We present MultiCellSeg, a segmentation algorithm to separate between multi-cellular and background regions for bright field images, which is based on classification of local patches within an image: a cascade of Support Vector Machines (SVMs) is applied using basic image features. Post processing includes additional classification and graph-cut segmentation to reclassify erroneous regions and refine the segmentation. This approach leads to a parameter-free and robust algorithm. Comparison to an alternative algorithm on wound healing assay images demonstrates its superiority. The proposed approach was used to evaluate common cell migration models such as wound healing and scatter assay. It was applied to quantify the acceleration effect of Hepatocyte growth factor/scatter factor (HGF/SF) on healing rate in a time lapse confocal microscopy wound healing assay and demonstrated that the healing rate is linear in both treated and untreated cells, and that HGF/SF accelerates the healing rate by approximately two-fold. A novel fully automated, accurate, zero-parameters method to classify and score scatter-assay images was developed and demonstrated that multi-cellular texture is an excellent descriptor to measure HGF/SF-induced cell scattering. We show that exploitation of textural information from differential interference contrast (DIC) images on the multi-cellular level can prove beneficial for the analyses of wound healing and scatter assays. The proposed approach is generic and can be used alone or alongside traditional fluorescence single-cell processing to perform objective, accurate quantitative analyses for various biological applications. PMID:22096600

Cell motility dynamics: a novel segmentation algorithm to quantify multi-cellular bright field microscopy images.

PubMed

Zaritsky, Assaf; Natan, Sari; Horev, Judith; Hecht, Inbal; Wolf, Lior; Ben-Jacob, Eshel; Tsarfaty, Ilan

2011-01-01

Confocal microscopy analysis of fluorescence and morphology is becoming the standard tool in cell biology and molecular imaging. Accurate quantification algorithms are required to enhance the understanding of different biological phenomena. We present a novel approach based on image-segmentation of multi-cellular regions in bright field images demonstrating enhanced quantitative analyses and better understanding of cell motility. We present MultiCellSeg, a segmentation algorithm to separate between multi-cellular and background regions for bright field images, which is based on classification of local patches within an image: a cascade of Support Vector Machines (SVMs) is applied using basic image features. Post processing includes additional classification and graph-cut segmentation to reclassify erroneous regions and refine the segmentation. This approach leads to a parameter-free and robust algorithm. Comparison to an alternative algorithm on wound healing assay images demonstrates its superiority. The proposed approach was used to evaluate common cell migration models such as wound healing and scatter assay. It was applied to quantify the acceleration effect of Hepatocyte growth factor/scatter factor (HGF/SF) on healing rate in a time lapse confocal microscopy wound healing assay and demonstrated that the healing rate is linear in both treated and untreated cells, and that HGF/SF accelerates the healing rate by approximately two-fold. A novel fully automated, accurate, zero-parameters method to classify and score scatter-assay images was developed and demonstrated that multi-cellular texture is an excellent descriptor to measure HGF/SF-induced cell scattering. We show that exploitation of textural information from differential interference contrast (DIC) images on the multi-cellular level can prove beneficial for the analyses of wound healing and scatter assays. The proposed approach is generic and can be used alone or alongside traditional fluorescence single-cell processing to perform objective, accurate quantitative analyses for various biological applications.

Enhancement of intrinsic optical signal recording with split spectrum optical coherence tomography

NASA Astrophysics Data System (ADS)

Thapa, Damber; Wang, Benquan; Lu, Yiming; Son, Taeyoon; Yao, Xincheng

2017-09-01

Functional optical coherence tomography (OCT) of stimulus-evoked intrinsic optical signal (IOS) promises to be a new methodology for high-resolution mapping of retinal neural dysfunctions. However, its practical applications for non-invasive examination of retinal function have been hindered by the low signal-to-noise ratio (SNR) and small magnitude of IOSs. Split spectrum amplitude-decorrelation has been demonstrated to improve the image quality of OCT angiography. In this study, we exploited split spectrum strategy to improve the sensitivity of IOS recording. The full OCT spectrum was split into multiple spectral bands and IOSs from each sub-band were calculated separately and then combined to generate a single IOS image sequence. The algorithm was tested on in vivo images of frog retinas. It significantly improved both IOS magnitude and SNR, which are essential for practical applications of functional IOS imaging.

VizieR Online Data Catalog: Jekyll & Hyde galaxies ALMA cube & spectrum (Schreiber+, 2018)

NASA Astrophysics Data System (ADS)

Schreiber, C.; Labbe, I.; Glazebrook, K.; Bekiaris, G.; Papovich, C.; Costa, T.; Elbaz, D.; Kacprzak, G. G.; Nanayakkara, T.; Oesch, P.; Pannella, M.; Spitler, L.; Straatman, C.; Tran, K.-V.; Wang, T.

2017-11-01

These files consist of the full ALMA data cube for the galaxies Jekyll and Hyde, together with the extracted continuum image and the spectrum of Hyde. The data cube was produced by CASA (v4.7.0), the continuum image was constructed as the weighted average in line-free channels, and the spectrum was extracted at the peak flux position of Hyde. The data cube and spectrum files contain two extensions, one for the flux, and another for the uncertainty. This uncertainty was determined from the RMS of the cube data between 2 and 8" away from the center. All fluxes are in units of Jansky, and the spectral axis is given in observed frequency (GHz). The images were not CLEANed, therefore the dirty beam (which is also provided here) is the correct point-spread function to use when analyzing these images. (2 data files).

Live-Cell Imaging of Mitochondria and the Actin Cytoskeleton in Budding Yeast.

PubMed

Higuchi-Sanabria, Ryo; Swayne, Theresa C; Boldogh, Istvan R; Pon, Liza A

2016-01-01

Maintenance and regulation of proper mitochondrial dynamics and functions are necessary for cellular homeostasis. Numerous diseases, including neurodegeneration and muscle myopathies, and overall cellular aging are marked by declining mitochondrial function and subsequent loss of multiple other cellular functions. For these reasons, optimized protocols are needed for visualization and quantification of mitochondria and their function and fitness. In budding yeast, mitochondria are intimately associated with the actin cytoskeleton and utilize actin for their movement and inheritance. This chapter describes optimal approaches for labeling mitochondria and the actin cytoskeleton in living budding yeast cells, for imaging the labeled cells, and for analyzing the resulting images.

Autism Spectrum Disorder: Does Neuroimaging Support the DSM-5 Proposal for a Symptom Dyad? A Systematic Review of Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging Studies

ERIC Educational Resources Information Center

Pina-Camacho, Laura; Villero, Sonia; Fraguas, David; Boada, Leticia; Janssen, Joost; Navas-Sanchez, Francisco J.; Mayoral, Maria; Llorente, Cloe; Arango, Celso; Parellada, Mara

2012-01-01

A systematic review of 208 studies comprising functional magnetic resonance imaging and diffusion tensor imaging data in patients with "autism spectrum disorder" (ASD) was conducted, in order to determine whether these data support the forthcoming DSM-5 proposal of a social communication and behavioral symptom dyad. Studies consistently reported…

Quantitative phase-digital holographic microscopy: a new imaging modality to identify original cellular biomarkers of diseases

NASA Astrophysics Data System (ADS)

Marquet, P.; Rothenfusser, K.; Rappaz, B.; Depeursinge, C.; Jourdain, P.; Magistretti, P. J.

2016-03-01

Quantitative phase microscopy (QPM) has recently emerged as a powerful label-free technique in the field of living cell imaging allowing to non-invasively measure with a nanometric axial sensitivity cell structure and dynamics. Since the phase retardation of a light wave when transmitted through the observed cells, namely the quantitative phase signal (QPS), is sensitive to both cellular thickness and intracellular refractive index related to the cellular content, its accurate analysis allows to derive various cell parameters and monitor specific cell processes, which are very likely to identify new cell biomarkers. Specifically, quantitative phase-digital holographic microscopy (QP-DHM), thanks to its numerical flexibility facilitating parallelization and automation processes, represents an appealing imaging modality to both identify original cellular biomarkers of diseases as well to explore the underlying pathophysiological processes.

Visual adaptation and the amplitude spectra of radiological images.

PubMed

Kompaniez-Dunigan, Elysse; Abbey, Craig K; Boone, John M; Webster, Michael A

2018-01-01

We examined how visual sensitivity and perception are affected by adaptation to the characteristic amplitude spectra of X-ray mammography images. Because of the transmissive nature of X-ray photons, these images have relatively more low-frequency variability than natural images, a difference that is captured by a steeper slope of the amplitude spectrum (~ - 1.5) compared to the ~ 1/f (slope of - 1) spectra common to natural scenes. Radiologists inspecting these images are therefore exposed to a different balance of spectral components, and we measured how this exposure might alter spatial vision. Observers (who were not radiologists) were adapted to images of normal mammograms or the same images sharpened by filtering the amplitude spectra to shallower slopes. Prior adaptation to the original mammograms significantly biased judgments of image focus relative to the sharpened images, demonstrating that the images are sufficient to induce substantial after-effects. The adaptation also induced strong losses in threshold contrast sensitivity that were selective for lower spatial frequencies, though these losses were very similar to the threshold changes induced by the sharpened images. Visual search for targets (Gaussian blobs) added to the images was also not differentially affected by adaptation to the original or sharper images. These results complement our previous studies examining how observers adapt to the textural properties or phase spectra of mammograms. Like the phase spectrum, adaptation to the amplitude spectrum of mammograms alters spatial sensitivity and visual judgments about the images. However, unlike the phase spectrum, adaptation to the amplitude spectra did not confer a selective performance advantage relative to more natural spectra.

Configuration of a high-content imaging platform for hit identification and pharmacological assessment of JMJD3 demethylase enzyme inhibitors.

PubMed

Mulji, Alpa; Haslam, Carl; Brown, Fiona; Randle, Rebecca; Karamshi, Bhumika; Smith, Julia; Eagle, Robert; Munoz-Muriedas, Jordi; Taylor, Joanna; Sheikh, Arshad; Bridges, Angela; Gill, Kirsty; Jepras, Rob; Smee, Penny; Barker, Mike; Woodrow, Mike; Liddle, John; Thomas, Pamela; Jones, Emma; Gordon, Laurie; Tanner, Rob; Leveridge, Melanie; Hutchinson, Sue; Martin, Margaret; Brown, Murray; Kruidenier, Laurens; Katso, Roy

2012-01-01

The biological complexity associated with the regulation of histone demethylases makes it desirable to configure a cellular mechanistic assay format that simultaneously encompasses as many of the relevant cellular processes as possible. In this report, the authors describe the configuration of a JMJD3 high-content cellular mechanistic imaging assay that uses single-cell multiparameter measurements to accurately assess cellular viability and the enzyme-dependent demethylation of the H3K27(Me)3 mark by exogenously expressed JMJD3. This approach couples robust statistical analyses with the spatial resolving power of cellular imaging. This enables segregation of expressing and nonexpressing cells into discrete subpopulations and consequently pharmacological quantification of compounds of interest in the expressing population at varying JMJD3 expression levels. Moreover, the authors demonstrate the utility of this hit identification strategy through the successful prosecution of a medium-throughput focused campaign of an 87 500-compound file, which has enabled the identification of JMJD3 cellular-active chemotypes. This study represents the first report of a demethylase high-content imaging assay with the ability to capture a repertoire of pharmacological tools, which are likely both to inform our mechanistic understanding of how JMJD3 is modulated and, more important, to contribute to the identification of novel therapeutic modalities for this demethylase enzyme.

Toxicological Tipping Points: Learning Boolean Networks from High-Content Imaging Data. (BOSC meeting)

EPA Science Inventory

The objective of this work is to elucidate biological networks underlying cellular tipping points using time-course data. We discretized the high-content imaging (HCI) data and inferred Boolean networks (BNs) that could accurately predict dynamic cellular trajectories. We found t...

Glucose-functionalized Au nanoprisms for optoacoustic imaging and near-infrared photothermal therapy

NASA Astrophysics Data System (ADS)

Han, Jishu; Zhang, Jingjing; Yang, Meng; Cui, Daxiang; de La Fuente, Jesus M.

2015-12-01

Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future.Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future. Electronic supplementary information (ESI) available: The evolution of the UV-vis absorption of Au NPrs by centrifugation, TEM image of PEG-capped Au NPrs, the UV-vis absorption of glucose, cytotoxicity of Au@PEG-Glc NPrs, gastric cell viabilities versus the concentration of Au@PEG-Glc NPrs and gastric cell viabilities filled with 80 μg Au@PEG-Glc NPrs versus the irradiation time, optoacoustic signals of Au NPr solution and Au@PEG NPrs. See DOI: 10.1039/c5nr06261f

Surface Chemistry Manipulation of Gold Nanorods Displays High Cellular Uptake In Vitro While Preserving Optical Properties for Bio-Imaging and Photo-Thermal Applications

DTIC Science & Technology

2016-03-28

PROPERTIES FOR BIO -IMAGING AND PHOTO-THERMAL APPLICATIONS ANTHONY B. POLITO III, Maj, USAF, BSC, PhD, MT(ASCP)SBB March 2016 Final Report for March...HIGH CELLULAR UPTAKE IN VITRO WHILE PRESERVING OPTICAL PROPERTIES FOR BIO -IMAGING AND PHOTO-THERMAL APPLICATIONS. 5a. CONTRACT NUMBER 5b...These findings identify MTAB-TA GNRs as prime candidates for use in nano-based bio -imaging and photo-thermal applications. 15. SUBJECT TERMS

Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

NASA Astrophysics Data System (ADS)

Liu, Shu-Quan; Bücherl, Thomas; Li, Hang; Zou, Yu-Bin; Lu, Yuan-Rong; Guo, Zhi-Yu

2013-11-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM- II in Technische Universität München (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

Automated and Adaptable Quantification of Cellular Alignment from Microscopic Images for Tissue Engineering Applications

PubMed Central

Xu, Feng; Beyazoglu, Turker; Hefner, Evan; Gurkan, Umut Atakan

2011-01-01

Cellular alignment plays a critical role in functional, physical, and biological characteristics of many tissue types, such as muscle, tendon, nerve, and cornea. Current efforts toward regeneration of these tissues include replicating the cellular microenvironment by developing biomaterials that facilitate cellular alignment. To assess the functional effectiveness of the engineered microenvironments, one essential criterion is quantification of cellular alignment. Therefore, there is a need for rapid, accurate, and adaptable methodologies to quantify cellular alignment for tissue engineering applications. To address this need, we developed an automated method, binarization-based extraction of alignment score (BEAS), to determine cell orientation distribution in a wide variety of microscopic images. This method combines a sequenced application of median and band-pass filters, locally adaptive thresholding approaches and image processing techniques. Cellular alignment score is obtained by applying a robust scoring algorithm to the orientation distribution. We validated the BEAS method by comparing the results with the existing approaches reported in literature (i.e., manual, radial fast Fourier transform-radial sum, and gradient based approaches). Validation results indicated that the BEAS method resulted in statistically comparable alignment scores with the manual method (coefficient of determination R2=0.92). Therefore, the BEAS method introduced in this study could enable accurate, convenient, and adaptable evaluation of engineered tissue constructs and biomaterials in terms of cellular alignment and organization. PMID:21370940

Analysis of security of optical encryption with spatially incoherent illumination technique

NASA Astrophysics Data System (ADS)

Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Shifrina, Anna V.

2017-03-01

Applications of optical methods for encryption purposes have been attracting interest of researchers for decades. The first and the most popular is double random phase encoding (DRPE) technique. There are many optical encryption techniques based on DRPE. Main advantage of DRPE based techniques is high security due to transformation of spectrum of image to be encrypted into white spectrum via use of first phase random mask which allows for encrypted images with white spectra. Downsides are necessity of using holographic registration scheme in order to register not only light intensity distribution but also its phase distribution, and speckle noise occurring due to coherent illumination. Elimination of these disadvantages is possible via usage of incoherent illumination instead of coherent one. In this case, phase registration no longer matters, which means that there is no need for holographic setup, and speckle noise is gone. This technique does not have drawbacks inherent to coherent methods, however, as only light intensity distribution is considered, mean value of image to be encrypted is always above zero which leads to intensive zero spatial frequency peak in image spectrum. Consequently, in case of spatially incoherent illumination, image spectrum, as well as encryption key spectrum, cannot be white. This might be used to crack encryption system. If encryption key is very sparse, encrypted image might contain parts or even whole unhidden original image. Therefore, in this paper analysis of security of optical encryption with spatially incoherent illumination depending on encryption key size and density is conducted.

Cellular resolution functional imaging in behaving rats using voluntary head restraint

PubMed Central

Scott, Benjamin B.; Brody, Carlos D.; Tank, David W.

2013-01-01

SUMMARY High-throughput operant conditioning systems for rodents provide efficient training on sophisticated behavioral tasks. Combining these systems with technologies for cellular resolution functional imaging would provide a powerful approach to study neural dynamics during behavior. Here we describe an integrated two-photon microscope and behavioral apparatus that allows cellular resolution functional imaging of cortical regions during epochs of voluntary head restraint. Rats were trained to initiate periods of restraint up to 8 seconds in duration, which provided the mechanical stability necessary for in vivo imaging while allowing free movement between behavioral trials. A mechanical registration system repositioned the head to within a few microns, allowing the same neuronal populations to be imaged on each trial. In proof-of-principle experiments, calcium dependent fluorescence transients were recorded from GCaMP-labeled cortical neurons. In contrast to previous methods for head restraint, this system can also be incorporated into high-throughput operant conditioning systems. PMID:24055015

An adaptive tensor voting algorithm combined with texture spectrum

NASA Astrophysics Data System (ADS)

Wang, Gang; Su, Qing-tang; Lü, Gao-huan; Zhang, Xiao-feng; Liu, Yu-huan; He, An-zhi

2015-01-01

An adaptive tensor voting algorithm combined with texture spectrum is proposed. The image texture spectrum is used to get the adaptive scale parameter of voting field. Then the texture information modifies both the attenuation coefficient and the attenuation field so that we can use this algorithm to create more significant and correct structures in the original image according to the human visual perception. At the same time, the proposed method can improve the edge extraction quality, which includes decreasing the flocculent region efficiently and making image clear. In the experiment for extracting pavement cracks, the original pavement image is processed by the proposed method which is combined with the significant curve feature threshold procedure, and the resulted image displays the faint crack signals submerged in the complicated background efficiently and clearly.

Development of optical probes for in vivo imaging of polarized macrophages during foreign body reactions

PubMed Central

Tsai, Yi-Ting; Patty, Kaitlen M; Weng, Hong; Tang, Ewin N.; Nair, Ashwin; Hu, Wen-Jing; Tang, Liping

2014-01-01

Plasticity of macrophages (MΦ) phenotypes exist in a spectrum from classically activated (M1) cells, to alternatively activated (M2) cells, contributing to both the normal healing of tissues and the pathogenesis of implant failure. Here, folate- and mannose-based optical probes were fabricated to simultaneously determine the degree of MΦ polarization. In vitro tests show the ability of these probes to specifically target M1 and M2 cells. In an in vivo murine model, they were able to distinguish between M1-dominated inflammatory response to infection and M2-dominated regenerative response to particle implants. Finally, the probes were used to assess the inflammatory/ regenerative property of biomaterial implants. Our results show that these probes can be used to monitor and quantify the dynamic processes of MΦ polarization and their role in cellular responses in real time. PMID:24726956

NASA Tech Briefs, April 2003

NASA Technical Reports Server (NTRS)

2003-01-01

Topics include: Tool for Bending a Metal Tube Precisely in a Confined Space; Multiple-Use Mechanisms for Attachment to Seat Tracks; Force-Measuring Clamps; Cellular Pressure-Actuated Joint; Block QCA Fault-Tolerant Logic Gates; Hybrid VLSI/QCA Architecture for Computing FFTs; Arrays of Carbon Nanotubes as RF Filters in Waveguides; Carbon Nanotubes as Resonators for RF Spectrum Analyzers; Software for Viewing Landsat Mosaic Images; Updated Integrated Mission Program; Software for Sharing and Management of Information; Optical-Quality Thin Polymer Membranes; Rollable Thin Shell Composite-Material Paraboloidal Mirrors; Folded Resonant Horns for Power Ultrasonic Applications; Touchdown Ball-Bearing System for Magnetic Bearings; Flux-Based Deadbeat Control of Induction-Motor Torque; Block Copolymers as Templates for Arrays of Carbon Nanotubes; Throttling Cryogen Boiloff To Control Cryostat Temperature; Collaborative Software Development Approach Used to Deliver the New Shuttle Telemetry Ground Station; Turbulence in Supercritical O2/H2 and C7H16/N2 Mixing Layers; and Time-Resolved Measurements in Optoelectronic Microbioanal.

Assessing the secretory capacity of pancreatic acinar cells.

PubMed

Geron, Erez; Schejter, Eyal D; Shilo, Ben-Zion

2014-08-28

Pancreatic acinar cells produce and secrete digestive enzymes. These cells are organized as a cluster which forms and shares a joint lumen. This work demonstrates how the secretory capacity of these cells can be assessed by culture of isolated acini. The setup is advantageous since isolated acini, which retain many characteristics of the intact exocrine pancreas can be manipulated and monitored more readily than in the whole animal. Proper isolation of pancreatic acini is a key requirement so that the ex vivo culture will represent the in vivo nature of the acini. The protocol demonstrates how to isolate intact acini from the mouse pancreas. Subsequently, two complementary methods for evaluating pancreatic secretion are presented. The amylase secretion assay serves as a global measure, while direct imaging of pancreatic secretion allows the characterization of secretion at a sub-cellular resolution. Collectively, the techniques presented here enable a broad spectrum of experiments to study exocrine secretion.

Cellular site of gastric acid secretion.

PubMed Central

DiBona, D R; Ito, S; Berglindh, T; Sachs, G

1979-01-01

Isolated gastric glands of the rabbit were examined both with differential interference-contrast microscopy and with electron microscopy to describe the morphologic correlates of acid secretion. Stimulation of the glands with histamine resulted in the development of intracellular spaces within the parietal cells. A similar transformation was produced by addition of 1 mM aminopyrine, whether the weak base was added in the presence of normal-K+ (5.4 mM) or high-K+ (108 mM) solutions. The intracellular space was compatible with the expanded canaliculus described in stimulated parietal cells. Confirmation that the space produced by histamine is the site of acid secretion was gained by combining fluorescence and interference-contrast methods in the presence of the dye acridine orange, which displays a pH-dependent metachromasia in its emission spectrum. Human gastrin I resulted in an observable discharge of peptic granules. Images PMID:42918

Scaling in geology: landforms and earthquakes.

PubMed Central

Turcotte, D L

1995-01-01

Landforms and earthquakes appear to be extremely complex; yet, there is order in the complexity. Both satisfy fractal statistics in a variety of ways. A basic question is whether the fractal behavior is due to scale invariance or is the signature of a broadly applicable class of physical processes. Both landscape evolution and regional seismicity appear to be examples of self-organized critical phenomena. A variety of statistical models have been proposed to model landforms, including diffusion-limited aggregation, self-avoiding percolation, and cellular automata. Many authors have studied the behavior of multiple slider-block models, both in terms of the rupture of a fault to generate an earthquake and in terms of the interactions between faults associated with regional seismicity. The slider-block models exhibit a remarkably rich spectrum of behavior; two slider blocks can exhibit low-order chaotic behavior. Large numbers of slider blocks clearly exhibit self-organized critical behavior. Images Fig. 6 PMID:11607562

Magnetic Particle Spectroscopy Reveals Dynamic Changes in the Magnetic Behavior of Very Small Superparamagnetic Iron Oxide Nanoparticles During Cellular Uptake and Enables Determination of Cell-Labeling Efficacy.

PubMed

Poller, Wolfram C; Löwa, Norbert; Wiekhorst, Frank; Taupitz, Matthias; Wagner, Susanne; Möller, Konstantin; Baumann, Gert; Stangl, Verena; Trahms, Lutz; Ludwig, Antje

2016-02-01

In vivo tracking of nanoparticle-labeled cells by magnetic resonance imaging (MRI) crucially depends on accurate determination of cell-labeling efficacy prior to transplantation. Here, we analyzed the feasibility and accuracy of magnetic particle spectroscopy (MPS) for estimation of cell-labeling efficacy in living THP-1 cells incubated with very small superparamagnetic iron oxide nanoparticles (VSOP). Cell viability and proliferation capacity were not affected by the MPS measurement procedure. In VSOP samples without cell contact, MPS enabled highly accurate quantification. In contrast, MPS constantly overestimated the amount of cell associated and internalized VSOP. Analyses of the MPS spectrum shape expressed as harmonic ratio A₅/A₃ revealed distinct changes in the magnetic behavior of VSOP in response to cellular uptake. These changes were proportional to the deviation between MPS and actual iron amount, therefore allowing for adjusted iron quantification. Transmission electron microscopy provided visual evidence that changes in the magnetic properties correlated with cell surface interaction of VSOP as well as with alterations of particle structure and arrangement during the phagocytic process. Altogether, A₅/A₃-adjusted MPS enables highly accurate, cell-preserving VSOP quantification and furthermore provides information on the magnetic characteristics of internalized VSOP.

Label-free imaging of gold nanoparticles in single live cells by photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Tian, Chao; Qian, Wei; Shao, Xia; Xie, Zhixing; Cheng, Xu; Liu, Shengchun; Cheng, Qian; Liu, Bing; Wang, Xueding

2016-03-01

Gold nanoparticles (AuNPs) have been extensively explored as a model nanostructure in nanomedicine and have been widely used to provide advanced biomedical research tools in diagnostic imaging and therapy. Due to the necessity of targeting AuNPs to individual cells, evaluation and visualization of AuNPs in the cellular level is critical to fully understand their interaction with cellular environment. Currently imaging technologies, such as fluorescence microscopy and transmission electron microscopy all have advantages and disadvantages. In this paper, we synthesized AuNPs by femtosecond pulsed laser ablation, modified their surface chemistry through sequential bioconjugation, and targeted the functionalized AuNPs with individual cancer cells. Based on their high optical absorption contrast, we developed a novel, label-free imaging method to evaluate and visualize intracellular AuNPs using photoacoustic microscopy (PAM). Preliminary study shows that the PAM imaging technique is capable of imaging cellular uptake of AuNPs in vivo at single-cell resolution, which provide an important tool for the study of AuNPs in nanomedicine.

Speckle reduction in digital holography with resampling ring masks

NASA Astrophysics Data System (ADS)

Zhang, Wenhui; Cao, Liangcai; Jin, Guofan

2018-01-01

One-shot digital holographic imaging has the advantages of high stability and low temporal cost. However, the reconstruction is affected by the speckle noise. Resampling ring-mask method in spectrum domain is proposed for speckle reduction. The useful spectrum of one hologram is divided into several sub-spectra by ring masks. In the reconstruction, angular spectrum transform is applied to guarantee the calculation accuracy which has no approximation. N reconstructed amplitude images are calculated from the corresponding sub-spectra. Thanks to speckle's random distribution, superimposing these N uncorrelated amplitude images would lead to a final reconstructed image with lower speckle noise. Normalized relative standard deviation values of the reconstructed image are used to evaluate the reduction of speckle. Effect of the method on the spatial resolution of the reconstructed image is also quantitatively evaluated. Experimental and simulation results prove the feasibility and effectiveness of the proposed method.

Spread spectrum image steganography.

PubMed

Marvel, L M; Boncelet, C R; Retter, C T

1999-01-01

In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

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.

Rocking-beam spectrum images and ALCHEMI of Ni{sub 50}Al{sub 40}Fe{sub 10}

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

Anderson, I.M.; Bentley, J.

1997-04-01

A rocking-beam energy-dispersive X-ray (EDX) spectrum image was acquired near the [035] zone axis of a B2-ordered alloy of composition Ni{sub 50}Al{sub 40}Fe{sub 10}. Images comparable to those acquired by Rossouw et al. were formed a posteriori by integrating the X-ray intensities in windows enclosing the Al-K, Fe-K{sub {alpha}}, and Ni-K{sub {alpha}} characteristic X-ray peaks for each pixel of the spectrum image. These images are shown along with a bright-field transmission channeling pattern (TCP), which records the signal from the bright-field STEM detector as the incident beam direction is varied with the beam-tilt coils, and an EDX spectrum from onemore » pixel of the image. The range of orientations from which the spectrum image was acquired is indicated by the square superimposed on the TCP. ALCHEMI (atom-location by channeling-enhanced microanalysis) was performed on a subset of the spectrum image using standard methods. Spectra from a series of {approximately}30 pixels along lines parallel to the (200) band were summed at each of 31 orientations relative to the band in the range 0 {le} {theta}/{theta}{sub 200} {le} 2.3. Characteristic X-ray intensities of the K-shell X-rays of Ni, Fe, and Al were extracted from the 31 summed spectra with the simplex fitting procedure of the DTSA spectral analysis software. The fraction of Fe on the `Ni`-site from this analysis, p{sub Fe`Ni`} = 23.8 {+-} 2.1%, is in excellent agreement with p{sub Fe`Ni`} = 23.7 {+-} 0.9%, which was determined by an analysis of a series of ten spectra acquired at orientations of the crystal carefully chosen so that the contributions of nonsystematic reflections are negligible.« less

Collaborative Initiative on Fetal Alcohol Spectrum Disorders: Methodology of Clinical Projects

PubMed Central

Mattson, Sarah N.; Foroud, Tatiana; Sowell, Elizabeth R.; Jones, Kenneth Lyons; Coles, Claire D.; Fagerlund, Åse; Autti-Rämö, Ilona; May, Philip A.; Adnams, Colleen M.; Konovalova, Valentina; Wetherill, Leah; Arenson, Andrew D.; Barnett, William K.; Riley, Edward P.

2009-01-01

The Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD) was created in 2003 to further understanding of fetal alcohol spectrum disorders. Clinical and basic science projects collect data across multiple sites using standardized methodology. This paper describes the methodology being used by the clinical projects that pertain to assessment of children and adolescents. Domains being addressed are dysmorphology, neurobehavior, 3D facial imaging, and brain imaging. PMID:20036488

Statistical analysis of low-voltage EDS spectrum images

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

Anderson, I.M.

1998-03-01

The benefits of using low ({le}5 kV) operating voltages for energy-dispersive X-ray spectrometry (EDS) of bulk specimens have been explored only during the last few years. This paper couples low-voltage EDS with two other emerging areas of characterization: spectrum imaging of a computer chip manufactured by a major semiconductor company. Data acquisition was performed with a Philips XL30-FEG SEM operated at 4 kV and equipped with an Oxford super-ATW detector and XP3 pulse processor. The specimen was normal to the electron beam and the take-off angle for acquisition was 35{degree}. The microscope was operated with a 150 {micro}m diameter finalmore » aperture at spot size 3, which yielded an X-ray count rate of {approximately}2,000 s{sup {minus}1}. EDS spectrum images were acquired as Adobe Photoshop files with the 4pi plug-in module. (The spectrum images could also be stored as NIH Image files, but the raw data are automatically rescaled as maximum-contrast (0--255) 8-bit TIFF images -- even at 16-bit resolution -- which poses an inconvenience for quantitative analysis.) The 4pi plug-in module is designed for EDS X-ray mapping and allows simultaneous acquisition of maps from 48 elements plus an SEM image. The spectrum image was acquired by re-defining the energy intervals of 48 elements to form a series of contiguous 20 eV windows from 1.25 kV to 2.19 kV. A spectrum image of 450 x 344 pixels was acquired from the specimen with a sampling density of 50 nm/pixel and a dwell time of 0.25 live seconds per pixel, for a total acquisition time of {approximately}14 h. The binary data files were imported into Mathematica for analysis with software developed by the author at Oak Ridge National Laboratory. A 400 x 300 pixel section of the original image was analyzed. MSA required {approximately}185 Mbytes of memory and {approximately}18 h of CPU time on a 300 MHz Power Macintosh 9600.« less

Hyperspectral remote sensing for terrestrial applications

USGS Publications Warehouse

Thenkabail, Prasad S.; Teluguntla, Pardhasaradhi G.; Murali Krishna Gumma,; Venkateswarlu Dheeravath,

2015-01-01

Remote sensing data are considered hyperspectral when the data are gathered from numerous wavebands, contiguously over an entire range of the spectrum (e.g., 400–2500 nm). Goetz (1992) defines hyperspectral remote sensing as “The acquisition of images in hundreds of registered, contiguous spectral bands such that for each picture element of an image it is possible to derive a complete reflectance spectrum.” However, Jensen (2004) defines hyperspectral remote sensing as “The simultaneous acquisition of images in many relatively narrow, contiguous and/or non contiguous spectral bands throughout the ultraviolet, visible, and infrared portions of the electromagnetic spectrum.

An echolocation model for the restoration of an acoustic image from a single-emission echo

NASA Astrophysics Data System (ADS)

Matsuo, Ikuo; Yano, Masafumi

2004-12-01

Bats can form a fine acoustic image of an object using frequency-modulated echolocation sound. The acoustic image is an impulse response, known as a reflected-intensity distribution, which is composed of amplitude and phase spectra over a range of frequencies. However, bats detect only the amplitude spectrum due to the low-time resolution of their peripheral auditory system, and the frequency range of emission is restricted. It is therefore necessary to restore the acoustic image from limited information. The amplitude spectrum varies with the changes in the configuration of the reflected-intensity distribution, while the phase spectrum varies with the changes in its configuration and location. Here, by introducing some reasonable constraints, a method is proposed for restoring an acoustic image from the echo. The configuration is extrapolated from the amplitude spectrum of the restricted frequency range by using the continuity condition of the amplitude spectrum at the minimum frequency of the emission and the minimum phase condition. The determination of the location requires extracting the amplitude spectra, which vary with its location. For this purpose, the Gaussian chirplets with a carrier frequency compatible with bat emission sweep rates were used. The location is estimated from the temporal changes of the amplitude spectra. .

Evaluation of imaging biomarkers for identification of single cancer cells in blood

NASA Astrophysics Data System (ADS)

Odaka, Masao; Kim, Hyonchol; Girault, Mathias; Hattori, Akihiro; Terazono, Hideyuki; Matsuura, Kenji; Yasuda, Kenji

2015-06-01

A method of discriminating single cancer cells from whole blood cells based on their morphological visual characteristics (i.e., “imaging biomarker”) was examined. Cells in healthy rat blood, a cancer cell line (MAT-LyLu), and cells in cancer-cell-implanted rat blood were chosen as models, and their bright-field (BF, whole-cell morphology) and fluorescence (FL, nucleus morphology) images were taken by an on-chip multi-imaging flow cytometry system and compared. Eight imaging biomarker indices, i.e., cellular area in a BF image, nucleus area in an FL image, area ratio of a whole cell and its nucleus, distance of the mass center between a whole cell and nucleus, cellular and nucleus perimeter, and perimeter ratios were calculated and analyzed using the BF and FL images taken. Results show that cancer cells can be clearly distinguished from healthy blood cells using correlation diagrams for cellular and nucleus areas as two different categories. Moreover, a portion of cancer cells showed a low nucleus perimeter ratio less than 0.9 because of the irregular nucleus morphologies of cancer cells. These results indicate that the measurements of imaging biomarkers are practically applicable to identifying cancer cells in blood.

Accurate Construction of Photoactivated Localization Microscopy (PALM) Images for Quantitative Measurements

PubMed Central

Coltharp, Carla; Kessler, Rene P.; Xiao, Jie

2012-01-01

Localization-based superresolution microscopy techniques such as Photoactivated Localization Microscopy (PALM) and Stochastic Optical Reconstruction Microscopy (STORM) have allowed investigations of cellular structures with unprecedented optical resolutions. One major obstacle to interpreting superresolution images, however, is the overcounting of molecule numbers caused by fluorophore photoblinking. Using both experimental and simulated images, we determined the effects of photoblinking on the accurate reconstruction of superresolution images and on quantitative measurements of structural dimension and molecule density made from those images. We found that structural dimension and relative density measurements can be made reliably from images that contain photoblinking-related overcounting, but accurate absolute density measurements, and consequently faithful representations of molecule counts and positions in cellular structures, require the application of a clustering algorithm to group localizations that originate from the same molecule. We analyzed how applying a simple algorithm with different clustering thresholds (tThresh and dThresh) affects the accuracy of reconstructed images, and developed an easy method to select optimal thresholds. We also identified an empirical criterion to evaluate whether an imaging condition is appropriate for accurate superresolution image reconstruction with the clustering algorithm. Both the threshold selection method and imaging condition criterion are easy to implement within existing PALM clustering algorithms and experimental conditions. The main advantage of our method is that it generates a superresolution image and molecule position list that faithfully represents molecule counts and positions within a cellular structure, rather than only summarizing structural properties into ensemble parameters. This feature makes it particularly useful for cellular structures of heterogeneous densities and irregular geometries, and allows a variety of quantitative measurements tailored to specific needs of different biological systems. PMID:23251611

Study on excitation and fluorescence spectrums of Japanese citruses to construct machine vision systems for acquiring fluorescent images

NASA Astrophysics Data System (ADS)

Momin, Md. Abdul; Kondo, Naoshi; Kuramoto, Makoto; Ogawa, Yuichi; Shigi, Tomoo

2011-06-01

Research was conducted to acquire knowledge of the ultraviolet and visible spectrums from 300 -800 nm of some common varieties of Japanese citrus, to investigate the best wave-lengths for fluorescence excitation and the resulting fluorescence wave-lengths and to provide a scientific background for the best quality fluorescent imaging technique for detecting surface defects of citrus. A Hitachi U-4000 PC-based microprocessor controlled spectrophotometer was used to measure the absorption spectrum and a Hitachi F-4500 spectrophotometer was used for the fluorescence and excitation spectrums. We analyzed the spectrums and the selected varieties of citrus were categorized into four groups of known fluorescence level, namely strong, medium, weak and no fluorescence.The level of fluorescence of each variety was also examined by using machine vision system. We found that around 340-380 nm LEDs or UV lamps are appropriate as lighting devices for acquiring the best quality fluorescent image of the citrus varieties to examine their fluorescence intensity. Therefore an image acquisition device was constructed with three different lighting panels with UV LED at peak 365 nm, Blacklight blue lamps (BLB) peak at 350 nm and UV-B lamps at peak 306 nm. The results from fluorescent images also revealed that the findings of the measured spectrums worked properly and can be used for practical applications such as for detecting rotten, injured or damaged parts of a wide variety of citrus.

Local region power spectrum-based unfocused ship detection method in synthetic aperture radar images

NASA Astrophysics Data System (ADS)

Wei, Xiangfei; Wang, Xiaoqing; Chong, Jinsong

2018-01-01

Ships on synthetic aperture radar (SAR) images will be severely defocused and their energy will disperse into numerous resolution cells under long SAR integration time. Therefore, the image intensity of ships is weak and sometimes even overwhelmed by sea clutter on SAR image. Consequently, it is hard to detect the ships from SAR intensity images. A ship detection method based on local region power spectrum of SAR complex image is proposed. Although the energies of the ships are dispersed on SAR intensity images, their spectral energies are rather concentrated or will cause the power spectra of local areas of SAR images to deviate from that of sea surface background. Therefore, the key idea of the proposed method is to detect ships via the power spectra distortion of local areas of SAR images. The local region power spectrum of a moving target on SAR image is analyzed and the way to obtain the detection threshold through the probability density function (pdf) of the power spectrum is illustrated. Numerical P- and L-band airborne SAR ocean data are utilized and the detection results are also illustrated. Results show that the proposed method can well detect the unfocused ships, with a detection rate of 93.6% and a false-alarm rate of 8.6%. Moreover, by comparing with some other algorithms, it indicates that the proposed method performs better under long SAR integration time. Finally, the applicability of the proposed method and the way of parameters selection are also discussed.

The Use of Color Sensors for Spectrographic Calibration

NASA Astrophysics Data System (ADS)

Thomas, Neil B.

2018-04-01

The wavelength calibration of spectrographs is an essential but challenging task in many disciplines. Calibration is traditionally accomplished by imaging the spectrum of a light source containing features that are known to appear at certain wavelengths and mapping them to their location on the sensor. This is typically required in conjunction with each scientific observation to account for mechanical and optical variations of the instrument over time, which may span years for certain projects. The method presented here investigates the usage of color itself instead of spectral features to calibrate a spectrograph. The primary advantage of such a calibration is that any broad-spectrum light source such as the sky or an incandescent bulb is suitable. This method allows for calibration using the full optical pathway of the instrument instead of incorporating separate calibration equipment that may introduce errors. This paper focuses on the potential for color calibration in the field of radial velocity astronomy, in which instruments must be finely calibrated for long periods of time to detect tiny Doppler wavelength shifts. This method is not restricted to radial velocity, however, and may find application in any field requiring calibrated spectrometers such as sea water analysis, cellular biology, chemistry, atmospheric studies, and so on. This paper demonstrates that color sensors have the potential to provide calibration with greatly reduced complexity.

Hodgkin's disease and CD30-positive anaplastic large cell lymphomas--a continuous spectrum of malignant disorders. A quantitative morphometric and immunohistologic study.

PubMed Central

Leoncini, L.; Del Vecchio, M. T.; Kraft, R.; Megha, T.; Barbini, P.; Cevenini, G.; Poggi, S.; Pileri, S.; Tosi, P.; Cottier, H.

1990-01-01

The authors have examined cellular areas of lymphoma tissue in 28 cases of Hodgkin's disease (HD) or anaplastic large cell lymphoma (ALCL, 'Ki-1 cell lymphoma') to evaluate the boundaries between the two entities. Methods applied included conventional histology; test point analysis; semiautomated morphometry of nuclear profile features of Reed-Sternberg and other atypical large cells (RSALCs); and immunohistochemistry of these elements on all paraffin sections and, in 15 cases, on frozen sections. Mean nuclear profile morphotypes of RSALCs per case varied independently of immunophenotype and histologic diagnosis. Conversely, immunohistochemistry demonstrated significant, although not consistent, preferential positivities of these CD30+ elements for CD15 in HD, and for epithelial membrane antigen (EMA) and CD43 in ALCLs. In the latter, RSALCs also exhibited a tendency for CD45 and CD45RO positivity and for the expression of T-cell-associated antigens. However, there were considerable overlaps. This continuous spectrum of RSALC nuclear profile morphotypes and immunophenotypes, ranging from HD over questionable cases, intermediate between HD and ALCL, to ALCLs, was paralleled by differences in the reactive component of lymphomas. Lymphocytes and granulocytes were significantly deficient in ALCLs. Images Figure 1 PMID:2173409

Coating barium titanate nanoparticles with polyethylenimine improves cellular uptake and allows for coupled imaging and gene delivery

PubMed Central

Dempsey, Christopher; Lee, Isac; Cowan, Katie; Suh, Junghae

2015-01-01

Barium titanate nanoparticles (BT NP) belong to a class of second harmonic generating (SHG) nanoprobes that have recently demonstrated promise in biological imaging. Unfortunately, BT NPs display low cellular uptake efficiencies, which may be a problem if cellular internalization is desired or required for a particular application. To overcome this issue, while concomitantly developing a particle platform that can also deliver nucleic acids into cells, we coated the BT NPs with the cationic polymer polyethylenimine (PEI) – one of the most effective nonviral gene delivery agents. Coating of BT with PEI yielded complexes with positive zeta potentials and resulted in an 8-fold increase in cellular uptake of the BT NPs. Importantly, we were able to achieve high levels of gene delivery with the BT-PEI/DNA complexes, supporting further efforts to generate BT platforms for coupled imaging and gene therapy. PMID:23973999

Asphalted Road Temperature Variations Due to Wind Turbine Cast Shadows

PubMed Central

Arnay, Rafael; Acosta, Leopoldo; Sigut, Marta; Toledo, Jonay

2009-01-01

The contribution of this paper is a technique that in certain circumstances allows one to avoid the removal of dynamic shadows in the visible spectrum making use of images in the infrared spectrum. This technique emerged from a real problem concerning the autonomous navigation of a vehicle in a wind farm. In this environment, the dynamic shadows cast by the wind turbines' blades make it necessary to include a shadows removal stage in the preprocessing of the visible spectrum images in order to avoid the shadows being misclassified as obstacles. In the thermal images, dynamic shadows completely disappear, something that does not always occur in the visible spectrum, even when the preprocessing is executed. Thus, a fusion on thermal and visible bands is performed. PMID:22291541

Fast energy spectrum and transverse beam profile monitoring and feedback systems for the SLC linac

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

Soderstrom, E.J.; Abrams, G.S.; Weinstein, A.J.

Fast energy spectrum and transverse beam profile monitoring systems have been tested at the SLC. The signals for each system are derived from digitizations of images on phosphor screens. Individual beam bunch images are digitized in the case of the transverse profile system and synchrotron radiation images produced by wiggler magnets for the energy spectrum. Measurements are taken at two-second intervals. Feedback elements have been installed for future use and consist of rf phase shifters to control energy spectrum and dipole correctors to control the beam launch into the linac affecting the transverse beam profile. Details of these systems, includingmore » hardware, timing, data acquisition, data reduction, measurement accuracy, and operational experience will be presented. 9 refs.« less

An image encryption algorithm based on 3D cellular automata and chaotic maps

NASA Astrophysics Data System (ADS)

Del Rey, A. Martín; Sánchez, G. Rodríguez

2015-05-01

A novel encryption algorithm to cipher digital images is presented in this work. The digital image is rendering into a three-dimensional (3D) lattice and the protocol consists of two phases: the confusion phase where 24 chaotic Cat maps are applied and the diffusion phase where a 3D cellular automata is evolved. The encryption method is shown to be secure against the most important cryptanalytic attacks.

MOVING BEYOND COLOR: THE CASE FOR MULTISPECTRAL IMAGING IN BRIGHTFIELD PATHOLOGY

PubMed Central

Cukierski, William J.; Qi, Xin; Foran, David J.

2009-01-01

A multispectral camera is capable of imaging a histologic slide at narrow bandwidths over the range of the visible spectrum. While several uses for multispectral imaging (MSI) have been demonstrated in pathology [1, 2], there is no unified consensus over when and how MSI might benefit automated analysis [3, 4]. In this work, we use a linear-algebra framework to investigate the relationship between the spectral image and its standard-image counterpart. The multispectral “cube” is treated as an extension of a traditional image in a high-dimensional color space. The concept of metamers is introduced and used to derive regions of the visible spectrum where MSI may provide an advantage. Furthermore, histological stains which are amenable to analysis by MSI are reported. We show the Commission internationale de l’éclairage (CIE) 1931 transformation from spectrum to color is non-neighborhood preserving. Empirical results are demonstrated on multispectral images of peripheral blood smears. PMID:19997528

High content image-based screening of a protease inhibitor library reveals compounds broadly active against Rift Valley fever virus and other highly pathogenic RNA viruses.

PubMed

Mudhasani, Rajini; Kota, Krishna P; Retterer, Cary; Tran, Julie P; Whitehouse, Chris A; Bavari, Sina

2014-08-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥ 50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology.

High Content Image-Based Screening of a Protease Inhibitor Library Reveals Compounds Broadly Active against Rift Valley Fever Virus and Other Highly Pathogenic RNA Viruses

PubMed Central

Mudhasani, Rajini; Kota, Krishna P.; Retterer, Cary; Tran, Julie P.; Whitehouse, Chris A.; Bavari, Sina

2014-01-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology. PMID:25144302

Beam Characterization at the Neutron Radiography Facility

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

Sarah Morgan; Jeffrey King

The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured themore » beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.« less

Phase imaging of mechanical properties of live cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wax, Adam

2017-02-01

The mechanisms by which cells respond to mechanical stimuli are essential for cell function yet not well understood. Many rheological tools have been developed to characterize cellular viscoelastic properties but these typically require direct mechanical contact, limiting their throughput. We have developed a new approach for characterizing the organization of subcellular structures using a label free, noncontact, single-shot phase imaging method that correlates to measured cellular mechanical stiffness. The new analysis approach measures refractive index variance and relates it to disorder strength. These measurements are compared to cellular stiffness, measured using the same imaging tool to visualize nanoscale responses to flow shear stimulus. The utility of the technique is shown by comparing shear stiffness and phase disorder strength across five cellular populations with varying mechanical properties. An inverse relationship between disorder strength and shear stiffness is shown, suggesting that cell mechanical properties can be assessed in a format amenable to high throughput studies using this novel, non-contact technique. Further studies will be presented which include examination of mechanical stiffness in early carcinogenic events and investigation of the role of specific cellular structural proteins in mechanotransduction.

Electromagnetic cellular interactions.

PubMed

Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

2011-05-01

Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

Spectral Imaging Technology-Based Evaluation of Radiation Treatment Planning to Remove Contrast Agent Artifacts.

PubMed

Yi-Qun, Xu; Wei, Liu; Xin-Ye, Ni

2016-10-01

This study employs dual-source computed tomography single-spectrum imaging to evaluate the effects of contrast agent artifact removal and the computational accuracy of radiotherapy treatment planning improvement. The phantom, including the contrast agent, was used in all experiments. The amounts of iodine in the contrast agent were 30, 15, 7.5, and 0.75 g/100 mL. Two images with different energy values were scanned and captured using dual-source computed tomography (80 and 140 kV). To obtain a fused image, 2 groups of images were processed using single-energy spectrum imaging technology. The Pinnacle planning system was used to measure the computed tomography values of the contrast agent and the surrounding phantom tissue. The difference between radiotherapy treatment planning based on 80 kV, 140 kV, and energy spectrum image was analyzed. For the image with high iodine concentration, the quality of the energy spectrum-fused image was the highest, followed by that of the 140-kV image. That of the 80-kV image was the worst. The difference in the radiotherapy treatment results among the 3 models was significant. When the concentration of iodine was 30 g/100 mL and the distance from the contrast agent at the dose measurement point was 1 cm, the deviation values (P) were 5.95% and 2.20% when image treatment planning was based on 80 and 140 kV, respectively. When the concentration of iodine was 15 g/100 mL, deviation values (P) were -2.64% and -1.69%. Dual-source computed tomography single-energy spectral imaging technology can remove contrast agent artifacts to improve the calculated dose accuracy in radiotherapy treatment planning. © The Author(s) 2015.

Flash X-Ray Apparatus With Spectrum Control Functions For Medical Use And Fuji Computed Radiography

NASA Astrophysics Data System (ADS)

Isobe, H.; Sato, E.; Hayasi, Y.; Suzuki, M.; Arima, H.; Hoshino, F.

1985-02-01

Flash radiographic bio-medical studies at sub-microsecond intervals were performed by using both a new type of flash X-ray(FX) apparatus with spectrum control functions and Fuji Computed Radiography(FCR). This single flasher tends to have a comparatively long exposure time and the electric pulse width of the FX wave form is about 0.3,usec. The maximum FX dose is about 50mR at 1m per pulse, and the effective focal spot varies according to condenser charging voltage, A-C distance, etc., ranging from 1.0 to 3.0mm in diameter, but in the low dose rate region it can be reduced to less than 1.0mm in diameter. The FX dose is determined by the condenser charging voltage and the A-C distance, while the FX spectrum is determined by the average voltage of the FX tube and filters. Various clear FX images were obtained by controlling the spectrum and dose. FCR is a new storage medium for medical radiography developed by the Fuji Photo Film Co., Ltd. and this apparatus has various image forming functions: low dose radiography, film density control, image contrast control, subtraction management and others. We have used this new apparatus in conjunction with our FX radiography and have obtained some new and interesting biomedical radiograms: the edge enhancement image, the instantaneous enlarged image, and the single exposure energy subtraction image using the FX spectrum distribution.

Polychromatic sparse image reconstruction and mass attenuation spectrum estimation via B-spline basis function expansion

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

Gu, Renliang, E-mail: Venliang@iastate.edu, E-mail: ald@iastate.edu; Dogandžić, Aleksandar, E-mail: Venliang@iastate.edu, E-mail: ald@iastate.edu

2015-03-31

We develop a sparse image reconstruction method for polychromatic computed tomography (CT) measurements under the blind scenario where the material of the inspected object and the incident energy spectrum are unknown. To obtain a parsimonious measurement model parameterization, we first rewrite the measurement equation using our mass-attenuation parameterization, which has the Laplace integral form. The unknown mass-attenuation spectrum is expanded into basis functions using a B-spline basis of order one. We develop a block coordinate-descent algorithm for constrained minimization of a penalized negative log-likelihood function, where constraints and penalty terms ensure nonnegativity of the spline coefficients and sparsity of themore » density map image in the wavelet domain. This algorithm alternates between a Nesterov’s proximal-gradient step for estimating the density map image and an active-set step for estimating the incident spectrum parameters. Numerical simulations demonstrate the performance of the proposed scheme.« less

Sequential Superresolution Imaging of Multiple Targets Using a Single Fluorophore

PubMed Central

Lidke, Diane S.; Lidke, Keith A.

2015-01-01

Fluorescence superresolution (SR) microscopy, or fluorescence nanoscopy, provides nanometer scale detail of cellular structures and allows for imaging of biological processes at the molecular level. Specific SR imaging methods, such as localization-based imaging, rely on stochastic transitions between on (fluorescent) and off (dark) states of fluorophores. Imaging multiple cellular structures using multi-color imaging is complicated and limited by the differing properties of various organic dyes including their fluorescent state duty cycle, photons per switching event, number of fluorescent cycles before irreversible photobleaching, and overall sensitivity to buffer conditions. In addition, multiple color imaging requires consideration of multiple optical paths or chromatic aberration that can lead to differential aberrations that are important at the nanometer scale. Here, we report a method for sequential labeling and imaging that allows for SR imaging of multiple targets using a single fluorophore with negligible cross-talk between images. Using brightfield image correlation to register and overlay multiple image acquisitions with ~10 nm overlay precision in the x-y imaging plane, we have exploited the optimal properties of AlexaFluor647 for dSTORM to image four distinct cellular proteins. We also visualize the changes in co-localization of the epidermal growth factor (EGF) receptor and clathrin upon EGF addition that are consistent with clathrin-mediated endocytosis. These results are the first to demonstrate sequential SR (s-SR) imaging using direct stochastic reconstruction microscopy (dSTORM), and this method for sequential imaging can be applied to any superresolution technique. PMID:25860558

Combining diffusion magnetic resonance tractography with stereology highlights increased cross-cortical integration in primates.

PubMed

Charvet, Christine J; Hof, Patrick R; Raghanti, Mary Ann; Van Der Kouwe, Andre J; Sherwood, Chet C; Takahashi, Emi

2017-04-01

The isocortex of primates is disproportionately expanded relative to many other mammals, yet little is known about what the expansion of the isocortex entails for differences in cellular composition and connectivity patterns in primates. Across the depth of the isocortex, neurons exhibit stereotypical patterns of projections. Upper-layer neurons (i.e., layers II-IV) project within and across cortical areas, whereas many lower-layer pyramidal neurons (i.e., layers V-VI) favor connections to subcortical regions. To identify evolutionary changes in connectivity patterns, we quantified upper (i.e., layers II-IV)- and lower (i.e., layers V-VI)-layer neuron numbers in primates and other mammals such as rodents and carnivores. We also used MR tractography based on high-angular resolution diffusion imaging and diffusion spectrum imaging to compare anterior-to-posterior corticocortical tracts between primates and other mammals. We found that primates possess disproportionately more upper-layer neurons as well as an expansion of anterior-to-posterior corticocortical tracts compared with other mammals. Taken together, these findings demonstrate that primates deviate from other mammals in exhibiting increased cross-cortical connectivity. J. Comp. Neurol. 525:1075-1093, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Proteomic analysis of Herbaspirillum seropedicae reveals ammonium-induced AmtB-dependent membrane sequestration of PII proteins.

PubMed

Huergo, Luciano F; Noindorf, Lilian; Gimenes, Camila; Lemgruber, Renato S P; Cordellini, Daniela F; Falarz, Lucas J; Cruz, Leonardo M; Monteiro, Rose A; Pedrosa, Fábio O; Chubatsu, Leda S; Souza, Emanuel M; Steffens, Maria B R

2010-07-01

This study was aimed at describing the spectrum and dynamics of proteins associated with the membrane in the nitrogen-fixing bacterium Herbaspirillum seropedicae according to the availability of fixed nitrogen. Using two-dimensional electrophoresis we identified 79 protein spots representing 45 different proteins in the membrane fraction of H. seropedicae. Quantitative analysis of gel images of membrane extracts indicated two spots with increased levels when cells were grown under nitrogen limitation in comparison with nitrogen sufficiency; these spots were identified as the GlnK protein and as a conserved noncytoplasmic protein of unknown function which was encoded in an operon together with GlnK and AmtB. Comparison of gel images of membrane extracts from cells grown under nitrogen limitation or under the same regime but collected after an ammonium shock revealed two proteins, GlnB and GlnK, with increased levels after the shock. The P(II) proteins were not present in the membrane fraction of an amtB mutant. The results reported here suggest that changes in the cellular localization of P(II) might play a role in the control of nitrogen metabolism in H. seropedicae.

Raman Imaging in Cell Membranes, Lipid-Rich Organelles, and Lipid Bilayers.

PubMed

Syed, Aleem; Smith, Emily A

2017-06-12

Raman-based optical imaging is a promising analytical tool for noninvasive, label-free chemical imaging of lipid bilayers and cellular membranes. Imaging using spontaneous Raman scattering suffers from a low intensity that hinders its use in some cellular applications. However, developments in coherent Raman imaging, surface-enhanced Raman imaging, and tip-enhanced Raman imaging have enabled video-rate imaging, excellent detection limits, and nanometer spatial resolution, respectively. After a brief introduction to these commonly used Raman imaging techniques for cell membrane studies, this review discusses selected applications of these modalities for chemical imaging of membrane proteins and lipids. Finally, recent developments in chemical tags for Raman imaging and their applications in the analysis of selected cell membrane components are summarized. Ongoing developments toward improving the temporal and spatial resolution of Raman imaging and small-molecule tags with strong Raman scattering cross sections continue to expand the utility of Raman imaging for diverse cell membrane studies.

[Fatty acids composition of cellular lipids of the collected and newly isolated Pseudomonas lupini strains].

PubMed

Hvozdiak, R I; Dankevych, L A; Votselko, S K; Holubets', O V

2005-01-01

Fatty acid composition of cellular lipids of 23 Pseudomonas lupini strains (Beltjukova et Koroljova 1968) has been investigated. Cellular fatty acids which contained from C10 to C19 carbon atoms have been identified. Basic fatty acid of those Pseudomonas cells are hexadecanoic, hexadecenoic and octadecanoic acids. The 3-hydroxydecanoic (C10:0 3OH), 3-hydroxydodecanoic (C12:0 3OH), 2-hydroxydodecanoic (C12:0 2OH) and cyclopropane fatty acids which contain 17 and 19 carbon atoms have been detected in cellular lipids. The cellular fatty acids spectra of 22 P. lupini strains are similar to cellular fatty acids spectrum of the type strain Pseudomonas syringae pv. syringae 8511. Pathogenic isolate 2, which fatty acid content of cell lipids significantly differ from lipids of cell fatty acids from P. lupini strains and cell lipids of fatty acids of typical strains Pseudomonas syringae pv. syringae 8511 and Pseudomonas savastanoi pv. phaseolicola 9066 is the exception.

A general method for radio spectrum efficiency defining

NASA Astrophysics Data System (ADS)

Ramadanovic, Ljubomir M.

1986-08-01

A general method for radio spectrum efficiency defining is proposed. Although simple it can be applied to various radio services. The concept of spectral elements, as information carriers, is introduced to enable the organization of larger spectral spaces - radio network models - characteristic for a particular radio network. The method is applied to some radio network models, concerning cellular radio telephone systems and digital radio relay systems, to verify its unified approach capability. All discussed radio services operate continuously.

Selective Detection of Neurotransmitters by Fluorescence and Chemiluminescence Imaging

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

Ziqiang Wang; Edward S. Yeung

In recent years, luminescence imaging has been widely employed in neurochemical analysis. It has a number of advantages for the study of neuronal and other biological cells: (1) a particular molecular species or cellular constituent can be selectively visualized in the presence of a large excess of other species in a heterogeneous environment; (2) low concentration detection limits can be achieved because of the inherent sensitivity associated with fluorescence and chemiluminescence; (3) low excitation intensities can be used so that long-term observation can be realized while the viability of the specimen is preserved; and (4) excellent spatial resolution can bemore » obtained with the light microscope so subcellular compartments can be identified. With good sensitivity, temporal and spatial resolution, the flux of ions and molecules and the distribution and dynamics of intracellular species can be measured in real time with specific luminescence probes, substrates, or with native fluorescence. A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with CCD imaging is down to {micro}M levels of glutamate with reasonable response time. They also found that chemiluminescence associated with the ATP-dependent reaction between luciferase and luciferin can be used to image ATP at levels down to 10 nM in the millisecond time scale. Similar imaging experiments should be feasible in a broad spectrum of biological systems.« less

Earlier Detection of Tumor Treatment Response Using Magnetic Resonance Diffusion Imaging with Oscillating Gradients

PubMed Central

Colvin, Daniel C.; Loveless, Mary E.; Does, Mark D.; Yue, Zou; Yankeelov, Thomas E.; Gore, John C.

2011-01-01

An improved method for detecting early changes in tumors in response to treatment, based on a modification of diffusion-weighted magnetic resonance imaging, has been demonstrated in an animal model. Early detection of therapeutic response in tumors is important both clinically and in pre-clinical assessments of novel treatments. Non-invasive imaging methods that can detect and assess tumor response early in the course of treatment, and before frank changes in tumor morphology are evident, are of considerable interest as potential biomarkers of treatment efficacy. Diffusion-weighted magnetic resonance imaging is sensitive to changes in water diffusion rates in tissues that result from structural variations in the local cellular environment, but conventional methods mainly reflect changes in tissue cellularity and do not convey information specific to micro-structural variations at sub-cellular scales. We implemented a modified imaging technique using oscillating gradients of the magnetic field for evaluating water diffusion rates over very short spatial scales that are more specific for detecting changes in intracellular structure that may precede changes in cellularity. Results from a study of orthotopic 9L gliomas in rat brains indicate that this method can detect changes as early as 24 hours following treatment with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), when conventional approaches do not find significant effects. These studies suggest that diffusion imaging using oscillating gradients may be used to obtain an earlier indication of treatment efficacy than previous magnetic resonance imaging methods. PMID:21190804

MO-DE-206-01: Cellular Metabolism of FDG

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

Pratx, G.

In this symposium jointly sponsored by the World Molecular Imaging Society (WMIS) and the AAPM, luminary speakers on imaging metabolism will discuss three impactful topics. The first presentation on Cellular Metabolism of FDG will be given by Guillem Pratx (Stanford). This presentation will detail new work on looking at how the most common molecular imaging agent, fluoro-deoxy-glucose is metabolized at a cellular level. This will be followed by a talk on an improved approach to whole-body PET imaging by Simon Cherry (UC Davis). Simon’s work on a new whole-body PET imaging system promises to have dramatic improvement in our abilitymore » to detect and characterize cancer using PET. Finally, Jim Bankson (MD Anderson) will discuss extremely sophisticated approaches to quantifying hyperpolarized-13-C pyruvate metabolism using MR imaging. This technology promises to compliment the exquisite sensitivity of PET with an ability to measure not just uptake, but tumor metabolism. Learning Objectives: Understand the metabolism of FDG at a cellular level. Appreciate the engineering related to a novel new high-sensitivity whole-body PET imaging system. Understand the process of hyperpolarization, how pyruvate relates to metabolism and how advanced modeling can be used to better quantify this data. G. Pratx, Funding: 5R01CA186275, 1R21CA193001, and Damon Runyon Cancer Foundation. S. Cherry, National Institutes of Health; University of California, Davis; Siemens Medical SolutionsJ. Bankson, GE Healthcare; NCI P30-CA016672; CPRIT PR140021-P5.« less

MO-DE-206-02: Cellular Metabolism of FDG

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

Cherry, S.

In this symposium jointly sponsored by the World Molecular Imaging Society (WMIS) and the AAPM, luminary speakers on imaging metabolism will discuss three impactful topics. The first presentation on Cellular Metabolism of FDG will be given by Guillem Pratx (Stanford). This presentation will detail new work on looking at how the most common molecular imaging agent, fluoro-deoxy-glucose is metabolized at a cellular level. This will be followed by a talk on an improved approach to whole-body PET imaging by Simon Cherry (UC Davis). Simon’s work on a new whole-body PET imaging system promises to have dramatic improvement in our abilitymore » to detect and characterize cancer using PET. Finally, Jim Bankson (MD Anderson) will discuss extremely sophisticated approaches to quantifying hyperpolarized-13-C pyruvate metabolism using MR imaging. This technology promises to compliment the exquisite sensitivity of PET with an ability to measure not just uptake, but tumor metabolism. Learning Objectives: Understand the metabolism of FDG at a cellular level. Appreciate the engineering related to a novel new high-sensitivity whole-body PET imaging system. Understand the process of hyperpolarization, how pyruvate relates to metabolism and how advanced modeling can be used to better quantify this data. G. Pratx, Funding: 5R01CA186275, 1R21CA193001, and Damon Runyon Cancer Foundation. S. Cherry, National Institutes of Health; University of California, Davis; Siemens Medical SolutionsJ. Bankson, GE Healthcare; NCI P30-CA016672; CPRIT PR140021-P5.« less

Examination of laser microbeam cell lysis in a PDMS microfluidic channel using time-resolved imaging

PubMed Central

Quinto-Su, Pedro A.; Lai, Hsuan-Hong; Yoon, Helen H.; Sims, Christopher E.; Allbritton, Nancy L.; Venugopalan, Vasan

2008-01-01

We use time-resolved imaging to examine the lysis dynamics of non-adherent BAF-3 cells within a microfluidic channel produced by the delivery of single highly-focused 540 ps duration laser pulses at λ = 532 nm. Time-resolved bright-field images reveal that the delivery of the pulsed laser microbeam results in the formation of a laser-induced plasma followed by shock wave emission and cavitation bubble formation. The confinement offered by the microfluidic channel constrains substantially the cavitation bubble expansion and results in significant deformation of the PDMS channel walls. To examine the cell lysis and dispersal of the cellular contents, we acquire time-resolved fluorescence images of the process in which the cells were loaded with a fluorescent dye. These fluorescence images reveal cell lysis to occur on the nanosecond to microsecond time scale by the plasma formation and cavitation bubble dynamics. Moreover, the time-resolved fluorescence images show that while the cellular contents are dispersed by the expansion of the laser-induced cavitation bubble, the flow associated with the bubble collapse subsequently re-localizes the cellular contents to a small region. This capacity of pulsed laser microbeam irradiation to achieve rapid cell lysis in microfluidic channels with minimal dilution of the cellular contents has important implications for their use in lab-on-a-chip applications. PMID:18305858

Multi-scale volumetric cell and tissue imaging based on optical projection tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ban, Sungbea; Cho, Nam Hyun; Ryu, Yongjae; Jung, Sunwoo; Vavilin, Andrey; Min, Eunjung; Jung, Woonggyu

2016-04-01

Optical projection tomography is a new optical imaging method for visualizing small biological specimens in three dimension. The most important advantage of OPT is to fill the gap between MRI and confocal microscope for the specimen having the range of 1-10 mm. Thus, it has been mainly used for whole-mount small animals and developmental study since this imaging modality was developed. The ability of OPT delivering anatomical and functional information of relatively large tissue in 3D has made it a promising platform in biomedical research. Recently, the potential of OPT spans its coverage to cellular scale. Even though there are increasing demand to obtain better understanding of cellular dynamics, only few studies to visualize cellular structure, shape, size and functional morphology over tissue has been investigated in existing OPT system due to its limited field of view. In this study, we develop a novel optical imaging system for 3D cellular imaging with OPT integrated with dynamic focusing technique. Our tomographic setup has great potential to be used for identifying cell characteristic in tissue because it can provide selective contrast on dynamic focal plane allowing for fluorescence as well as absorption. While the dominant contrast of optical imaging technique is to use the fluorescence for detecting certain target only, the newly developed OPT system will offer considerable advantages over currently available method when imaging cellar molecular dynamics by permitting contrast variation. By achieving multi-contrast, it is expected for this new imaging system to play an important role in delivering better cytological information to pathologist.

Quantitation of Cellular Dynamics in Growing Arabidopsis Roots with Light Sheet Microscopy

PubMed Central

Birnbaum, Kenneth D.; Leibler, Stanislas

2011-01-01

To understand dynamic developmental processes, living tissues have to be imaged frequently and for extended periods of time. Root development is extensively studied at cellular resolution to understand basic mechanisms underlying pattern formation and maintenance in plants. Unfortunately, ensuring continuous specimen access, while preserving physiological conditions and preventing photo-damage, poses major barriers to measurements of cellular dynamics in growing organs such as plant roots. We present a system that integrates optical sectioning through light sheet fluorescence microscopy with hydroponic culture that enables us to image, at cellular resolution, a vertically growing Arabidopsis root every few minutes and for several consecutive days. We describe novel automated routines to track the root tip as it grows, to track cellular nuclei and to identify cell divisions. We demonstrate the system's capabilities by collecting data on divisions and nuclear dynamics. PMID:21731697

High-speed 3D imaging of cellular activity in the brain using axially-extended beams and light sheets.

PubMed

Hillman, Elizabeth Mc; Voleti, Venkatakaushik; Patel, Kripa; Li, Wenze; Yu, Hang; Perez-Campos, Citlali; Benezra, Sam E; Bruno, Randy M; Galwaduge, Pubudu T

2018-06-01

As optical reporters and modulators of cellular activity have become increasingly sophisticated, the amount that can be learned about the brain via high-speed cellular imaging has increased dramatically. However, despite fervent innovation, point-scanning microscopy is facing a fundamental limit in achievable 3D imaging speeds and fields of view. A range of alternative approaches are emerging, some of which are moving away from point-scanning to use axially-extended beams or sheets of light, for example swept confocally aligned planar excitation (SCAPE) microscopy. These methods are proving effective for high-speed volumetric imaging of the nervous system of small organisms such as Drosophila (fruit fly) and D. Rerio (Zebrafish), and are showing promise for imaging activity in the living mammalian brain using both single and two-photon excitation. This article describes these approaches and presents a simple model that demonstrates key advantages of axially-extended illumination over point-scanning strategies for high-speed volumetric imaging, including longer integration times per voxel, improved photon efficiency and reduced photodamage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Spread spectrum image watermarking based on perceptual quality metric.

PubMed

Zhang, Fan; Liu, Wenyu; Lin, Weisi; Ngan, King Ngi

2011-11-01

Efficient image watermarking calls for full exploitation of the perceptual distortion constraint. Second-order statistics of visual stimuli are regarded as critical features for perception. This paper proposes a second-order statistics (SOS)-based image quality metric, which considers the texture masking effect and the contrast sensitivity in Karhunen-Loève transform domain. Compared with the state-of-the-art metrics, the quality prediction by SOS better correlates with several subjectively rated image databases, in which the images are impaired by the typical coding and watermarking artifacts. With the explicit metric definition, spread spectrum watermarking is posed as an optimization problem: we search for a watermark to minimize the distortion of the watermarked image and to maximize the correlation between the watermark pattern and the spread spectrum carrier. The simple metric guarantees the optimal watermark a closed-form solution and a fast implementation. The experiments show that the proposed watermarking scheme can take full advantage of the distortion constraint and improve the robustness in return.

Imaging live cells at high spatiotemporal resolution for lab-on-a-chip applications.

PubMed

Chin, Lip Ket; Lee, Chau-Hwang; Chen, Bi-Chang

2016-05-24

Conventional optical imaging techniques are limited by the diffraction limit and difficult-to-image biomolecular and sub-cellular processes in living specimens. Novel optical imaging techniques are constantly evolving with the desire to innovate an imaging tool that is capable of seeing sub-cellular processes in a biological system, especially in three dimensions (3D) over time, i.e. 4D imaging. For fluorescence imaging on live cells, the trade-offs among imaging depth, spatial resolution, temporal resolution and photo-damage are constrained based on the limited photons of the emitters. The fundamental solution to solve this dilemma is to enlarge the photon bank such as the development of photostable and bright fluorophores, leading to the innovation in optical imaging techniques such as super-resolution microscopy and light sheet microscopy. With the synergy of microfluidic technology that is capable of manipulating biological cells and controlling their microenvironments to mimic in vivo physiological environments, studies of sub-cellular processes in various biological systems can be simplified and investigated systematically. In this review, we provide an overview of current state-of-the-art super-resolution and 3D live cell imaging techniques and their lab-on-a-chip applications, and finally discuss future research trends in new and breakthrough research areas of live specimen 4D imaging in controlled 3D microenvironments.

Developing Mirror Self Awareness in Students with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Duff, Christine K.; Flattery, J. J., Jr.

2014-01-01

A teaching methodology and curriculum was designed to develop and increase positive self-awareness in students diagnosed with autism spectrum disorders (ASD). Joint attention (JA) strategies were first utilized to directly teach students about reflected mirror images, and then subsequently, to indirectly teach students about their reflected image.…

Microstructural Abnormalities of Short-Distance White Matter Tracts in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Shukla, Dinesh K.; Keehn, Brandon; Smylie, Daren M.; Muller, Ralph-Axel

2011-01-01

Recent functional connectivity magnetic resonance imaging and diffusion tensor imaging (DTI) studies have suggested atypical functional connectivity and reduced integrity of long-distance white matter fibers in autism spectrum disorder (ASD). However, evidence for short-distance white matter fibers is still limited, despite some speculation of…

Live imaging of dense-core vesicles in primary cultured hippocampal neurons.

PubMed

Kwinter, David M; Silverman, Michael A; Kwinter, David; Michael, Silverman

2009-05-29

Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images. Vital fluorescent probes, particularly green fluorescent protein (GFP) have revolutionized cell biology stemming from the ability to label specific intracellular compartments and cellular structures. For example, the live imaging of GFP (and its spectral variants) chimeras have allowed for a dynamic analysis of the cytoskeleton, organelle transport, and membrane dynamics in a multitude of organisms and cell types [1-3]. Although live imaging has become prevalent, this approach still poses many technical challenges, particularly in primary cultured neurons. One challenge is the expression of GFP-tagged proteins in post-mitotic neurons; the other is the ability to capture fluorescent images while minimizing phototoxicity, photobleaching, and maintaining general cell health. Here we provide a protocol that describes a lipid-based transfection method that yields a relatively low transfection rate (~0.5%), however is ideal for the imaging of fully polarized neurons. A low transfection rate is essential so that single axons and dendrites can be characterized as to their orientation to the cell body to confirm directionality of transport, i.e., anterograde v. retrograde. Our approach to imaging GFP expressing neurons relies on a standard wide-field fluorescent microscope outfitted with a CCD camera, image capture software, and a heated imaging chamber. We have imaged a wide variety of organelles or structures, for example, dense-core vesicles, mitochondria, growth cones, and actin without any special optics or excitation requirements other than a fluorescent light source. Additionally, spectrally-distinct, fluorescently labeled proteins, e.g., GFP and dsRed-tagged proteins, can be visualized near simultaneously to characterize co-transport or other coordinated cellular events. The imaging approach described here is flexible for a variety of imaging applications and can be adopted by a laboratory for relatively little cost provided a microscope is available.

Comparison with the horizontal phase velocity distribution of gravity waves observed airglow imaging data of different sampling periods

NASA Astrophysics Data System (ADS)

Matsuda, T. S.; Nakamura, T.; Ejiri, M. K.; Tsutsumi, M.; Shiokawa, K.

2014-12-01

Atmospheric gravity waves (AGWs), which are generated in the lower atmosphere, transport significant amount of energy and momentum into the mesosphere and lower thermosphere. Among many parameters to characterize AGWs, horizontal phase velocity is very important to discuss the vertical propagation. Airglow imaging is a useful technique for investigating the horizontal structures of AGWs around mesopause. There are many airglow imagers operated all over the world, and a large amount of data which could improve our understanding of AGWs propagation direction and source distribution in the MLT region. We have developed a new statistical analysis method for obtaining the power spectrum in the horizontal phase velocity domain (phase velocity spectrum), from airglow image data, so as to deal with huge amounts of imaging data obtained on different years and at various observation sites, without bias caused by different event extraction criteria for the observer. From a series of images projected onto the geographic coordinates, 3-D Fourier transform is applied and 3-D power spectrum in horizontal wavenumber and frequency domain is obtained. Then, it is converted into phase velocity and frequency domain. Finally, the spectrum is integrated along the frequency for the range of interest and 2-D spectrum in horizontal phase velocity is calculated. This method was applied to the data obtained at Syowa Station (69ºS, 40ºE), Antarctica, in 2011 and compared with a conventional event analysis in which the phase fronts were traced manually in order to estimate horizontal propagation characteristics. This comparison shows that our new method is adequate to deriving the horizontal phase velocity characteristics of AGWs observed by airglow imaging technique. Airglow imaging observation has been operated with various sampling intervals. We also presents how the images with different sample interval should be treated.

Computer vision in cell biology.

PubMed

Danuser, Gaudenz

2011-11-23

Computer vision refers to the theory and implementation of artificial systems that extract information from images to understand their content. Although computers are widely used by cell biologists for visualization and measurement, interpretation of image content, i.e., the selection of events worth observing and the definition of what they mean in terms of cellular mechanisms, is mostly left to human intuition. This Essay attempts to outline roles computer vision may play and should play in image-based studies of cellular life. Copyright © 2011 Elsevier Inc. All rights reserved.

Optical super resolution using tilted illumination coupled with object rotation

NASA Astrophysics Data System (ADS)

Hussain, Anwar; Mudassar, Asloob A.

2015-03-01

In conventional imaging systems, the resolution of the final image is mainly distorted due to diffraction of higher spatial frequencies of the target object. To overcome the diffraction limit, imaging techniques which synthetically enlarge the aperture of the system are used. In this paper, synthesized aperture is produced by means of a three fiber illumination assembly coupled with an in-plane object rotation. The high order diffracted spatial frequencies of the object are brought into the pass band of optical system by illuminating the object with tilted beams. The tilt produced at the fiber assembly plane is related to the dimension of the aperture, placed at the Fourier plane of the system. To span the 2D object spectrum at the Fourier plane, an in-plane object rotation procedure is applied at the object plane. The spectrum of the object is rotated as the object is rotated and illuminated with tilted beams. The corresponding object beam is interfered with a reference beam from the same source to record interferograms. All the recorded interferograms are stored in computer and de-convolution algorithm is applied to recover the synthesized spectrum. The image of the synthesized spectrum has three times improved resolution compared to the conventional image.

Spectral Prior Image Constrained Compressed Sensing (Spectral PICCS) for Photon-Counting Computed Tomography

PubMed Central

Yu, Zhicong; Leng, Shuai; Li, Zhoubo; McCollough, Cynthia H.

2016-01-01

Photon-counting computed tomography (PCCT) is an emerging imaging technique that enables multi-energy imaging with only a single scan acquisition. To enable multi-energy imaging, the detected photons corresponding to the full x-ray spectrum are divided into several subgroups of bin data that correspond to narrower energy windows. Consequently, noise in each energy bin increases compared to the full-spectrum data. This work proposes an iterative reconstruction algorithm for noise suppression in the narrower energy bins used in PCCT imaging. The algorithm is based on the framework of prior image constrained compressed sensing (PICCS) and is called spectral PICCS; it uses the full-spectrum image reconstructed using conventional filtered back-projection as the prior image. The spectral PICCS algorithm is implemented using a constrained optimization scheme with adaptive iterative step sizes such that only two tuning parameters are required in most cases. The algorithm was first evaluated using computer simulations, and then validated by both physical phantoms and in-vivo swine studies using a research PCCT system. Results from both computer-simulation and experimental studies showed substantial image noise reduction in narrow energy bins (43~73%) without sacrificing CT number accuracy or spatial resolution. PMID:27551878

Spectral prior image constrained compressed sensing (spectral PICCS) for photon-counting computed tomography

NASA Astrophysics Data System (ADS)

Yu, Zhicong; Leng, Shuai; Li, Zhoubo; McCollough, Cynthia H.

2016-09-01

Photon-counting computed tomography (PCCT) is an emerging imaging technique that enables multi-energy imaging with only a single scan acquisition. To enable multi-energy imaging, the detected photons corresponding to the full x-ray spectrum are divided into several subgroups of bin data that correspond to narrower energy windows. Consequently, noise in each energy bin increases compared to the full-spectrum data. This work proposes an iterative reconstruction algorithm for noise suppression in the narrower energy bins used in PCCT imaging. The algorithm is based on the framework of prior image constrained compressed sensing (PICCS) and is called spectral PICCS; it uses the full-spectrum image reconstructed using conventional filtered back-projection as the prior image. The spectral PICCS algorithm is implemented using a constrained optimization scheme with adaptive iterative step sizes such that only two tuning parameters are required in most cases. The algorithm was first evaluated using computer simulations, and then validated by both physical phantoms and in vivo swine studies using a research PCCT system. Results from both computer-simulation and experimental studies showed substantial image noise reduction in narrow energy bins (43-73%) without sacrificing CT number accuracy or spatial resolution.

Fusion of infrared and visible images based on saliency scale-space in frequency domain

NASA Astrophysics Data System (ADS)

Chen, Yanfei; Sang, Nong; Dan, Zhiping

2015-12-01

A fusion algorithm of infrared and visible images based on saliency scale-space in the frequency domain was proposed. Focus of human attention is directed towards the salient targets which interpret the most important information in the image. For the given registered infrared and visible images, firstly, visual features are extracted to obtain the input hypercomplex matrix. Secondly, the Hypercomplex Fourier Transform (HFT) is used to obtain the salient regions of the infrared and visible images respectively, the convolution of the input hypercomplex matrix amplitude spectrum with a low-pass Gaussian kernel of an appropriate scale which is equivalent to an image saliency detector are done. The saliency maps are obtained by reconstructing the 2D signal using the original phase and the amplitude spectrum, filtered at a scale selected by minimizing saliency map entropy. Thirdly, the salient regions are fused with the adoptive weighting fusion rules, and the nonsalient regions are fused with the rule based on region energy (RE) and region sharpness (RS), then the fused image is obtained. Experimental results show that the presented algorithm can hold high spectrum information of the visual image, and effectively get the thermal targets information at different scales of the infrared image.

Time series modeling of live-cell shape dynamics for image-based phenotypic profiling.

PubMed

Gordonov, Simon; Hwang, Mun Kyung; Wells, Alan; Gertler, Frank B; Lauffenburger, Douglas A; Bathe, Mark

2016-01-01

Live-cell imaging can be used to capture spatio-temporal aspects of cellular responses that are not accessible to fixed-cell imaging. As the use of live-cell imaging continues to increase, new computational procedures are needed to characterize and classify the temporal dynamics of individual cells. For this purpose, here we present the general experimental-computational framework SAPHIRE (Stochastic Annotation of Phenotypic Individual-cell Responses) to characterize phenotypic cellular responses from time series imaging datasets. Hidden Markov modeling is used to infer and annotate morphological state and state-switching properties from image-derived cell shape measurements. Time series modeling is performed on each cell individually, making the approach broadly useful for analyzing asynchronous cell populations. Two-color fluorescent cells simultaneously expressing actin and nuclear reporters enabled us to profile temporal changes in cell shape following pharmacological inhibition of cytoskeleton-regulatory signaling pathways. Results are compared with existing approaches conventionally applied to fixed-cell imaging datasets, and indicate that time series modeling captures heterogeneous dynamic cellular responses that can improve drug classification and offer additional important insight into mechanisms of drug action. The software is available at http://saphire-hcs.org.

Information and image integration: project spectrum

NASA Astrophysics Data System (ADS)

Blaine, G. James; Jost, R. Gilbert; Martin, Lori; Weiss, David A.; Lehmann, Ron; Fritz, Kevin

1998-07-01

The BJC Health System (BJC) and the Washington University School of Medicine (WUSM) formed a technology alliance with industry collaborators to develop and implement an integrated, advanced clinical information system. The industry collaborators include IBM, Kodak, SBC and Motorola. The activity, called Project Spectrum, provides an integrated clinical repository for the multiple hospital facilities of the BJC. The BJC System consists of 12 acute care hospitals serving over one million patients in Missouri and Illinois. An interface engine manages transactions from each of the hospital information systems, lab systems and radiology information systems. Data is normalized to provide a consistent view for the primary care physician. Access to the clinical repository is supported by web-based server/browser technology which delivers patient data to the physician's desktop. An HL7 based messaging system coordinates the acquisition and management of radiological image data and sends image keys to the clinical data repository. Access to the clinical chart browser currently provides radiology reports, laboratory data, vital signs and transcribed medical reports. A chart metaphor provides tabs for the selection of the clinical record for review. Activation of the radiology tab facilitates a standardized view of radiology reports and provides an icon used to initiate retrieval of available radiology images. The selection of the image icon spawns an image browser plug-in and utilizes the image key from the clinical repository to access the image server for the requested image data. The Spectrum system is collecting clinical data from five hospital systems and imaging data from two hospitals. Domain specific radiology imaging systems support the acquisition and primary interpretation of radiology exams. The spectrum clinical workstations are deployed to over 200 sites utilizing local area networks and ISDN connectivity.

Molecular and Cellular Quantitative Microscopy: theoretical investigations, technological developments and applications to neurobiology

NASA Astrophysics Data System (ADS)

Esposito, Alessandro

2006-05-01

This PhD project aims at the development and evaluation of microscopy techniques for the quantitative detection of molecular interactions and cellular features. The primarily investigated techniques are Fαrster Resonance Energy Transfer imaging and Fluorescence Lifetime Imaging Microscopy. These techniques have the capability to quantitatively probe the biochemical environment of fluorophores. An automated microscope capable of unsupervised operation has been developed that enables the investigation of molecular and cellular properties at high throughput levels and the analysis of cellular heterogeneity. State-of-the-art Förster Resonance Energy Transfer imaging, Fluorescence Lifetime Imaging Microscopy, Confocal Laser Scanning Microscopy and the newly developed tools have been combined with cellular and molecular biology techniques for the investigation of protein-protein interactions, oligomerization and post-translational modifications of α-Synuclein and Tau, two proteins involved in Parkinson’s and Alzheimer’s disease, respectively. The high inter-disciplinarity of this project required the merging of the expertise of both the Molecular Biophysics Group at the Debye Institute - Utrecht University and the Cell Biophysics Group at the European Neuroscience Institute - Gαttingen University. This project was conducted also with the support and the collaboration of the Center for the Molecular Physiology of the Brain (Göttingen), particularly with the groups associated with the Molecular Quantitative Microscopy and Parkinson’s Disease and Aggregopathies areas. This work demonstrates that molecular and cellular quantitative microscopy can be used in combination with high-throughput screening as a powerful tool for the investigation of the molecular mechanisms of complex biological phenomena like those occurring in neurodegenerative diseases.

Noise Power Spectrum in PROPELLER MR Imaging.

PubMed

Ichinoseki, Yuki; Nagasaka, Tatsuo; Miyamoto, Kota; Tamura, Hajime; Mori, Issei; Machida, Yoshio

2015-01-01

The noise power spectrum (NPS), an index for noise evaluation, represents the frequency characteristics of image noise. We measured the NPS in PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) magnetic resonance (MR) imaging, a nonuniform data sampling technique, as an initial study for practical MR image evaluation using the NPS. The 2-dimensional (2D) NPS reflected the k-space sampling density and showed agreement with the shape of the k-space trajectory as expected theoretically. Additionally, the 2D NPS allowed visualization of a part of the image reconstruction process, such as filtering and motion correction.

Video System Highlights Hydrogen Fires

NASA Technical Reports Server (NTRS)

Youngquist, Robert C.; Gleman, Stuart M.; Moerk, John S.

1992-01-01

Video system combines images from visible spectrum and from three bands in infrared spectrum to produce color-coded display in which hydrogen fires distinguished from other sources of heat. Includes linear array of 64 discrete lead selenide mid-infrared detectors operating at room temperature. Images overlaid on black and white image of same scene from standard commercial video camera. In final image, hydrogen fires appear red; carbon-based fires, blue; and other hot objects, mainly green and combinations of green and red. Where no thermal source present, image remains in black and white. System enables high degree of discrimination between hydrogen flames and other thermal emitters.

The spectrum of MR imaging in athletic pubalgia.

PubMed

Zoga, Adam C; Mullens, Frank E; Meyers, William C

2010-11-01

Many athletes struggle with groin pain for years without ever receiving a clear diagnosis or being offered an effective treatment plan. Confusion among treatment providers can also frequently lead to suboptimal surgeries for presumed hernias or nerve entrapment syndromes. Imaging, and in particular magnetic resonance (MR) imaging, should play a primary role in the workup, diagnosis, and treatment of athletic pubalgia. This review outlines standard of care, cutting-edge MR imaging techniques for athletic pubalgia, and reviews the spectrum of imaging findings that are encountered in this patient group. Copyright © 2010 Elsevier Inc. All rights reserved.

Feasibility evaluation of 3D photoacoustic imaging of blood vessel structure using multiple wavelengths with a handheld probe

NASA Astrophysics Data System (ADS)

Uchimoto, Yo; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

2018-02-01

Photoacoustic imaging is anticipated for use in portraying blood vessel structures (e.g. neovascularization in inflamed regions). To reduce invasiveness and enhance ease handling, we developed a handheld photoacoustic imaging system using multiple wavelengths. The usefulness of the proposed system was investigated in phantom experiments and in vivo measurements. A silicon tube was embedded into chicken breast meat to simulate the blood vessel. The tube was filled with ovine blood. Then laser light was guided to the phantom surface by an optical fiber bundle close to the linear ultrasound probe. Photoacoustic images were obtained at 750-950 nm wavelengths. Strong photoacoustic signals from the boundary between blood and silicon tube are observed in these images. The shape of photoacoustic spectrum at the boundary resembles that of the HbO2 absorption spectrum at 750-920 nm. In photoacoustic images, similarity between photoacoustic spectrum and HbO2 absorption spectrum was evaluated by calculating the normalized correlation coefficient. Results show high correlation in regions of strong photoacoustic signals in photoacoustic images. These analyses demonstrate the feasibility of portraying blood vessel structures under practical conditions. To evaluate the feasibility of three-dimensional vascular imaging, in vivo experiments were conducted using three wavelengths. A right hand and ultrasound probe were set in degassed water. By scanning a probe, cross-sectional ultrasound and photoacoustic images were obtained at each location. Then, all ultrasound or photoacoustic images were piled up respectively. Then three-dimensional images were constructed. Resultant images portrayed blood vessel-like structures three-dimensionally. Furthermore, to distinguish blood vessels from other tissues (e.g. skin), distinguishing images of them were constructed by comparing photoacoustic signal intensity among three wavelengths. The resultant image portrayed blood vessels as distinguished from surrounding tissues. These results demonstrated the usefulness of the proposed imaging device.

Wireless teleradiology and fax using cellular phones and notebook PCs for instant access to consultants.

PubMed

Yamamoto, L G

1995-03-01

The feasibility of wireless portable teleradiology and facsimile (fax) transmission using a pocket cellular phone and a notebook computer to obtain immediate access to consultants at any location was studied. Modems specially designed for data and fax communication via cellular systems were employed to provide a data communication interface between the cellular phone and the notebook computer. Computed tomography (CT) scans, X-rays, and electrocardiograms (ECGs) were transmitted to a wireless unit to measure performance characteristics. Data transmission rates ranged from 520 to 1100 bytes per second. Typical image transmission times ranged from 1 to 10 minutes; however, using joint photographic experts group or fractal image compression methods would shorten typical transmission times to less than one minute. This study showed that wireless teleradiology and fax over cellular communication systems are feasible with current technology. Routine immediate cellular faxing of ECGs to cardiologists may expedite thrombolytic therapy decisions in questionable cases. Routine immediate teleradiology of CT scans may reduce operation room preparation times in severe head trauma.

Under the Microscope: Single-Domain Antibodies for Live-Cell Imaging and Super-Resolution Microscopy.

PubMed

Traenkle, Bjoern; Rothbauer, Ulrich

2017-01-01

Single-domain antibodies (sdAbs) have substantially expanded the possibilities of advanced cellular imaging such as live-cell or super-resolution microscopy to visualize cellular antigens and their dynamics. In addition to their unique properties including small size, high stability, and solubility in many environments, sdAbs can be efficiently functionalized according to the needs of the respective imaging approach. Genetically encoded intrabodies fused to fluorescent proteins (chromobodies) have become versatile tools to study dynamics of endogenous proteins in living cells. Additionally, sdAbs conjugated to organic dyes were shown to label cellular structures with high density and minimal fluorophore displacement making them highly attractive probes for super-resolution microscopy. Here, we review recent advances of the chromobody technology to visualize localization and dynamics of cellular targets and the application of chromobody-based cell models for compound screening. Acknowledging the emerging importance of super-resolution microscopy in cell biology, we further discuss advantages and challenges of sdAbs for this technology.

A Quantitative Microscopy Technique for Determining the Number of Specific Proteins in Cellular Compartments

PubMed Central

Mutch, Sarah A.; Gadd, Jennifer C.; Fujimoto, Bryant S.; Kensel-Hammes, Patricia; Schiro, Perry G.; Bajjalieh, Sandra M.; Chiu, Daniel T.

2013-01-01

This protocol describes a method to determine both the average number and variance of proteins in the few to tens of copies in isolated cellular compartments, such as organelles and protein complexes. Other currently available protein quantification techniques either provide an average number but lack information on the variance or are not suitable for reliably counting proteins present in the few to tens of copies. This protocol entails labeling the cellular compartment with fluorescent primary-secondary antibody complexes, TIRF (total internal reflection fluorescence) microscopy imaging of the cellular compartment, digital image analysis, and deconvolution of the fluorescence intensity data. A minimum of 2.5 days is required to complete the labeling, imaging, and analysis of a set of samples. As an illustrative example, we describe in detail the procedure used to determine the copy number of proteins in synaptic vesicles. The same procedure can be applied to other organelles or signaling complexes. PMID:22094731

Cellular image segmentation using n-agent cooperative game theory

NASA Astrophysics Data System (ADS)

Dimock, Ian B.; Wan, Justin W. L.

2016-03-01

Image segmentation is an important problem in computer vision and has significant applications in the segmentation of cellular images. Many different imaging techniques exist and produce a variety of image properties which pose difficulties to image segmentation routines. Bright-field images are particularly challenging because of the non-uniform shape of the cells, the low contrast between cells and background, and imaging artifacts such as halos and broken edges. Classical segmentation techniques often produce poor results on these challenging images. Previous attempts at bright-field imaging are often limited in scope to the images that they segment. In this paper, we introduce a new algorithm for automatically segmenting cellular images. The algorithm incorporates two game theoretic models which allow each pixel to act as an independent agent with the goal of selecting their best labelling strategy. In the non-cooperative model, the pixels choose strategies greedily based only on local information. In the cooperative model, the pixels can form coalitions, which select labelling strategies that benefit the entire group. Combining these two models produces a method which allows the pixels to balance both local and global information when selecting their label. With the addition of k-means and active contour techniques for initialization and post-processing purposes, we achieve a robust segmentation routine. The algorithm is applied to several cell image datasets including bright-field images, fluorescent images and simulated images. Experiments show that the algorithm produces good segmentation results across the variety of datasets which differ in cell density, cell shape, contrast, and noise levels.

Two-photon excited autofluorescence imaging of freshly isolated frog retinas.

PubMed

Lu, Rong-Wen; Li, Yi-Chao; Ye, Tong; Strang, Christianne; Keyser, Kent; Curcio, Christine A; Yao, Xin-Cheng

2011-06-01

The purpose of this study was to investigate cellular sources of autofluorescence signals in freshly isolated frog (Rana pipiens) retinas. Equipped with an ultrafast laser, a laser scanning two-photon excitation fluorescence microscope was employed for sub-cellular resolution examination of both sliced and flat-mounted retinas. Two-photon imaging of retinal slices revealed autofluorescence signals over multiple functional layers, including the photoreceptor layer (PRL), outer nuclear layer (ONL), outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL), and ganglion cell layer (GCL). Using flat-mounted retinas, depth-resolved imaging of individual retinal layers further confirmed multiple sources of autofluorescence signals. Cellular structures were clearly observed at the PRL, ONL, INL, and GCL. At the PRL, the autofluorescence was dominantly recorded from the intracellular compartment of the photoreceptors; while mixed intracellular and extracellular autofluorescence signals were observed at the ONL, INL, and GCL. High resolution autofluorescence imaging clearly revealed mosaic organization of rod and cone photoreceptors; and sub-cellular bright autofluorescence spots, which might relate to connecting cilium, was observed in the cone photoreceptors only. Moreover, single-cone and double-cone outer segments could be directly differentiated.

A Novel Water-Soluble Fluorescence Probe with Wash-Free Cellular Imaging Capacity Based on AIE Characteristics.

PubMed

Qian, Yunxia; Liu, Hongmei; Tan, Haijian; Yang, Qingmin; Zhang, Shuchen; Han, Lingui; Yi, Xuegang; Huo, Li; Zhao, Hongchi; Wu, Yonggang; Bai, Libin; Ba, Xinwu

2017-05-01

A potential real-time imaging water-soluble fluorescent polymer (P3) is facilely prepared via one-pot method. For P3, tetraphenylethene unit serves as the fluorescent unit, poly(acryloyl ethylene diamine) (a kind of polyelectrolyte) with specific degree of polymerization acts as water-soluble part. 1 H-NMR, gel permeation chromatography (GPC), UV-vis spectroscopy, photoluminescence (PL), and confocal laser scanning microscopy are undertaken to characterize the structure and property of P3. The results of wash-free cellular imaging show that the signal-to-noise ratio is high as the concentration of P3 is 50 μg mL -1 . In addition, the pH-responsive and Cd 2+ -responsive are also investigated in this paper. The results coming from pH-responsive show that P3 solution displays significant fluorescence under near neutral. And the result from the cellular imaging shows that intracellular fluorescence intensity enhances with the augment of concentration of Cd 2+ , which reveals that P3 can give a hint to resolve the dilemma of traditional fluorescent dyes used as living cellular fluorescent probe. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A quantitative image cytometry technique for time series or population analyses of signaling networks.

PubMed

Ozaki, Yu-ichi; Uda, Shinsuke; Saito, Takeshi H; Chung, Jaehoon; Kubota, Hiroyuki; Kuroda, Shinya

2010-04-01

Modeling of cellular functions on the basis of experimental observation is increasingly common in the field of cellular signaling. However, such modeling requires a large amount of quantitative data of signaling events with high spatio-temporal resolution. A novel technique which allows us to obtain such data is needed for systems biology of cellular signaling. We developed a fully automatable assay technique, termed quantitative image cytometry (QIC), which integrates a quantitative immunostaining technique and a high precision image-processing algorithm for cell identification. With the aid of an automated sample preparation system, this device can quantify protein expression, phosphorylation and localization with subcellular resolution at one-minute intervals. The signaling activities quantified by the assay system showed good correlation with, as well as comparable reproducibility to, western blot analysis. Taking advantage of the high spatio-temporal resolution, we investigated the signaling dynamics of the ERK pathway in PC12 cells. The QIC technique appears as a highly quantitative and versatile technique, which can be a convenient replacement for the most conventional techniques including western blot, flow cytometry and live cell imaging. Thus, the QIC technique can be a powerful tool for investigating the systems biology of cellular signaling.

Spatial Mapping of Lipids at Cellular Resolution in Embryos of Cotton[W][OA

PubMed Central

Horn, Patrick J.; Korte, Andrew R.; Neogi, Purnima B.; Love, Ebony; Fuchs, Johannes; Strupat, Kerstin; Borisjuk, Ljudmilla; Shulaev, Vladimir; Lee, Young-Jin; Chapman, Kent D.

2012-01-01

Advances in mass spectrometry (MS) have made comprehensive lipidomics analysis of complex tissues relatively commonplace. These compositional analyses, although able to resolve hundreds of molecular species of lipids in single extracts, lose the original cellular context from which these lipids are derived. Recently, high-resolution MS of individual lipid droplets from seed tissues indicated organelle-to-organelle variation in lipid composition, suggesting that heterogeneity of lipid distributions at the cellular level may be prevalent. Here, we employed matrix-assisted laser desorption/ionization–MS imaging (MALDI-MSI) approaches to visualize lipid species directly in seed tissues of upland cotton (Gossypium hirsutum). MS imaging of cryosections of mature cotton embryos revealed a distinct, heterogeneous distribution of molecular species of triacylglycerols and phosphatidylcholines, the major storage and membrane lipid classes in cotton embryos. Other lipids were imaged, including phosphatidylethanolamines, phosphatidic acids, sterols, and gossypol, indicating the broad range of metabolites and applications for this chemical visualization approach. We conclude that comprehensive lipidomics images generated by MALDI-MSI report accurate, relative amounts of lipid species in plant tissues and reveal previously unseen differences in spatial distributions providing for a new level of understanding in cellular biochemistry. PMID:22337917

Self-registering spread-spectrum barcode method

DOEpatents

Cummings, Eric B.; Even Jr., William R.

2004-11-09

A novel spread spectrum barcode methodology is disclosed that allows a barcode to be read in its entirety even when a significant fraction or majority of the barcode is obscured. The barcode methodology makes use of registration or clocking information that is distributed along with the encoded user data across the barcode image. This registration information allows for the barcode image to be corrected for imaging distortion such as zoom, rotation, tilt, curvature, and perspective.

Coherence and diffraction limited resolution in microscopic OCT by a unified approach for the correction of dispersion and aberrations

NASA Astrophysics Data System (ADS)

Schulz-Hildebrandt, H.; Münter, Michael; Ahrens, M.; Spahr, H.; Hillmann, D.; König, P.; Hüttmann, G.

2018-03-01

Optical coherence tomography (OCT) images scattering tissues with 5 to 15 μm resolution. This is usually not sufficient for a distinction of cellular and subcellular structures. Increasing axial and lateral resolution and compensation of artifacts caused by dispersion and aberrations is required to achieve cellular and subcellular resolution. This includes defocus which limit the usable depth of field at high lateral resolution. OCT gives access the phase of the scattered light and hence correction of dispersion and aberrations is possible by numerical algorithms. Here we present a unified dispersion/aberration correction which is based on a polynomial parameterization of the phase error and an optimization of the image quality using Shannon's entropy. For validation, a supercontinuum light sources and a costume-made spectrometer with 400 nm bandwidth were combined with a high NA microscope objective in a setup for tissue and small animal imaging. Using this setup and computation corrections, volumetric imaging at 1.5 μm resolution is possible. Cellular and near cellular resolution is demonstrated in porcine cornea and the drosophila larva, when computational correction of dispersion and aberrations is used. Due to the excellent correction of the used microscope objective, defocus was the main contribution to the aberrations. In addition, higher aberrations caused by the sample itself were successfully corrected. Dispersion and aberrations are closely related artifacts in microscopic OCT imaging. Hence they can be corrected in the same way by optimization of the image quality. This way microscopic resolution is easily achieved in OCT imaging of static biological tissues.

Cathodoluminescence | Materials Science | NREL

Science.gov Websites

image, the time to acquire the entire spectrum series is about five minutes. When the acquisition is ) processes the spectrum series to reconstruct images of the photon emission (energy resolved) or to extract : Mapping of the photon energy and full-width-half maximum of selected transitions ASCII output Quantitative

Hyperspectral Imaging Sensors and the Marine Coastal Zone

NASA Technical Reports Server (NTRS)

Richardson, Laurie L.

2000-01-01

Hyperspectral imaging sensors greatly expand the potential of remote sensing to assess, map, and monitor marine coastal zones. Each pixel in a hyperspectral image contains an entire spectrum of information. As a result, hyperspectral image data can be processed in two very different ways: by image classification techniques, to produce mapped outputs of features in the image on a regional scale; and by use of spectral analysis of the spectral data embedded within each pixel of the image. The latter is particularly useful in marine coastal zones because of the spectral complexity of suspended as well as benthic features found in these environments. Spectral-based analysis of hyperspectral (AVIRIS) imagery was carried out to investigate a marine coastal zone of South Florida, USA. Florida Bay is a phytoplankton-rich estuary characterized by taxonomically distinct phytoplankton assemblages and extensive seagrass beds. End-member spectra were extracted from AVIRIS image data corresponding to ground-truth sample stations and well-known field sites. Spectral libraries were constructed from the AVIRIS end-member spectra and used to classify images using the Spectral Angle Mapper (SAM) algorithm, a spectral-based approach that compares the spectrum, in each pixel of an image with each spectrum in a spectral library. Using this approach different phytoplankton assemblages containing diatoms, cyanobacteria, and green microalgae, as well as benthic community (seagrasses), were mapped.

Imaging Cell Shape Change in Living Drosophila Embryos

PubMed Central

Figard, Lauren; Sokac, Anna Marie

2011-01-01

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging. Cell shape changes in the fly are analogous to those in higher organisms, and they drive tissue morphogenesis. So, in many cases, their study has direct implications for understanding human disease (Table 1)1-5. On the sub-cellular scale, these cell shape changes are the product of activities ranging from gene expression to signal transduction, cell polarity, cytoskeletal remodeling and membrane trafficking. Thus, the Drosophila embryo provides not only the context to evaluate cell shape changes as they relate to tissue morphogenesis, but also offers a completely physiological environment to study the sub-cellular activities that shape cells. The protocol described here is designed to image a specific cell shape change called cellularization. Cellularization is a process of dramatic plasma membrane growth, and it ultimately converts the syncytial embryo into the cellular blastoderm. That is, at interphase of mitotic cycle 14, the plasma membrane simultaneously invaginates around each of ~6000 cortically anchored nuclei to generate a sheet of primary epithelial cells. Counter to previous suggestions, cellularization is not driven by Myosin-2 contractility6, but is instead fueled largely by exocytosis of membrane from internal stores7. Thus, cellularization is an excellent system for studying membrane trafficking during cell shape changes that require plasma membrane invagination or expansion, such as cytokinesis or transverse-tubule (T-tubule) morphogenesis in muscle. Note that this protocol is easily applied to the imaging of other cell shape changes in the fly embryo, and only requires slight adaptations such as changing the stage of embryo collection, or using "embryo glue" to mount the embryo in a specific orientation (Table 1)8-19. In all cases, the workflow is basically the same (Figure 1). Standard methods for cloning and Drosophila transgenesis are used to prepare stable fly stocks that express a protein of interest, fused to Green Fluorescent Protein (GFP) or its variants, and these flies provide a renewable source of embryos. Alternatively, fluorescent proteins/probes are directly introduced into fly embryos via straightforward micro-injection techniques9-10. Then, depending on the developmental event and cell shape change to be imaged, embryos are collected and staged by morphology on a dissecting microscope, and finally positioned and mounted for time-lapse imaging on a confocal microscope. PMID:21490577

Movies of cellular and sub-cellular motion by digital holographic microscopy.

PubMed

Mann, Christopher J; Yu, Lingfeng; Kim, Myung K

2006-03-23

Many biological specimens, such as living cells and their intracellular components, often exhibit very little amplitude contrast, making it difficult for conventional bright field microscopes to distinguish them from their surroundings. To overcome this problem phase contrast techniques such as Zernike, Normarsky and dark-field microscopies have been developed to improve specimen visibility without chemically or physically altering them by the process of staining. These techniques have proven to be invaluable tools for studying living cells and furthering scientific understanding of fundamental cellular processes such as mitosis. However a drawback of these techniques is that direct quantitative phase imaging is not possible. Quantitative phase imaging is important because it enables determination of either the refractive index or optical thickness variations from the measured optical path length with sub-wavelength accuracy. Digital holography is an emergent phase contrast technique that offers an excellent approach in obtaining both qualitative and quantitative phase information from the hologram. A CCD camera is used to record a hologram onto a computer and numerical methods are subsequently applied to reconstruct the hologram to enable direct access to both phase and amplitude information. Another attractive feature of digital holography is the ability to focus on multiple focal planes from a single hologram, emulating the focusing control of a conventional microscope. A modified Mach-Zender off-axis setup in transmission is used to record and reconstruct a number of holographic amplitude and phase images of cellular and sub-cellular features. Both cellular and sub-cellular features are imaged with sub-micron, diffraction-limited resolution. Movies of holographic amplitude and phase images of living microbes and cells are created from a series of holograms and reconstructed with numerically adjustable focus, so that the moving object can be accurately tracked with a reconstruction rate of 300ms for each hologram. The holographic movies show paramecium swimming among other microbes as well as displaying some of their intracellular processes. A time lapse movie is also shown for fibroblast cells in the process of migration. Digital holography and movies of digital holography are seen to be useful new tools for visualization of dynamic processes in biological microscopy. Phase imaging digital holography is a promising technique in terms of the lack of coherent noise and the precision with which the optical thickness of a sample can be profiled, which can lead to images with an axial resolution of a few nanometres.

Cellular Factors Shape 3D Genome Landscape

Cancer.gov

Researchers, using novel large-scale imaging technology, have mapped the spatial location of individual genes in the nucleus of human cells and identified 50 cellular factors required for the proper 3D positioning of genes. These spatial locations play important roles in gene expression, DNA repair, genome stability, and other cellular activities.

77 FR 2738 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-19

..., Review Group; Clinical Molecular Imaging and Probe Development. Date: February 2-3, 2012. Time: 7 p.m. to..., Bethesda, MD 20892, (301) 435-1777, [email protected] . Name of Committee: Molecular, Cellular and...: Molecular, Cellular and Developmental Neuroscience Integrated Review Group; Cellular and Molecular Biology...

SU-E-QI-19: Evaluation of a Clinical 1.5T MRI for Prostate Cancer MRS Imaging Using a In Vivo Tumor Model

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

Chen, X; Chen, L; Hensley, H

2014-06-15

Purpose: Magnetic resonance spectroscopic (MRS) imaging may provide important bio-markers to distinguish normal/cancerous prostate tissue. While MRS imaging requires a high uniform magnetic field, the ability of a clinical 1.5T MRI to achieve a comparable MRS signal is of interest for radiation treatment planning/assessment. This study is to evaluate the MRS imaging of a 1.5T clinical MRI for prostate cancers by comparing with a small animal 7T MRS scanner. Methods: A tumor model was developed by implanting LNCaP tumor cells in nude mice prostates. Tumor was monitored 3 weeks after implantation using MRI, and MRS imaging was performed on themore » tumor area when the tumor reached around 1cm in diameter. The 1.5T GE clinical MR scanner and the 7T Bruker small animal MR scanner were used for each mouse. MR spectrums acquired with these scanners were analyzed and compared. The signals of Choline and Citrate were considered. Results: The prostate tumor MR spectrum under the 1.5T clinical MRI showed a similar spectrum pattern to that acquired using the 7T animal MRI. The Choline signal (3.2ppm) is clear and there is no clear peak for Citrate (2.6ppm). However, the signal magnitude for Choline is not dominant compared to the background signal under 1.5T MRI. Typical cancerous prostate tissue MR spectrum with an increased Choline signal and a reduced Citrate signal was observed. In addition, signal variation is noticeable between repeated spectrum scans. The average of these scans showed a comparable and consistent spectrum to those under 7T MRI. Conclusion: The clinical 1.5T MRI is able to acquire a MR spectrum for prostate cancer comparable to those acquired using a dedicated 7T MRS scanner. However, to achieve a consistent and reliable spectrum, multiple repeated scans were necessary to get a statistical result and reduce the noise-induced artifact. This work was supported in part by the National Cancer Institute Grant R21 CA131979 and R01CA172638.« less

Breast cancer mitosis detection in histopathological images with spatial feature extraction

NASA Astrophysics Data System (ADS)

Albayrak, Abdülkadir; Bilgin, Gökhan

2013-12-01

In this work, cellular mitosis detection in histopathological images has been investigated. Mitosis detection is very expensive and time consuming process. Development of digital imaging in pathology has enabled reasonable and effective solution to this problem. Segmentation of digital images provides easier analysis of cell structures in histopathological data. To differentiate normal and mitotic cells in histopathological images, feature extraction step is very crucial step for the system accuracy. A mitotic cell has more distinctive textural dissimilarities than the other normal cells. Hence, it is important to incorporate spatial information in feature extraction or in post-processing steps. As a main part of this study, Haralick texture descriptor has been proposed with different spatial window sizes in RGB and La*b* color spaces. So, spatial dependencies of normal and mitotic cellular pixels can be evaluated within different pixel neighborhoods. Extracted features are compared with various sample sizes by Support Vector Machines using k-fold cross validation method. According to the represented results, it has been shown that separation accuracy on mitotic and non-mitotic cellular pixels gets better with the increasing size of spatial window.

Live animal myelin histomorphometry of the spinal cord with video-rate multimodal nonlinear microendoscopy

NASA Astrophysics Data System (ADS)

Bélanger, Erik; Crépeau, Joël; Laffray, Sophie; Vallée, Réal; De Koninck, Yves; Côté, Daniel

2012-02-01

In vivo imaging of cellular dynamics can be dramatically enabling to understand the pathophysiology of nervous system diseases. To fully exploit the power of this approach, the main challenges have been to minimize invasiveness and maximize the number of concurrent optical signals that can be combined to probe the interplay between multiple cellular processes. Label-free coherent anti-Stokes Raman scattering (CARS) microscopy, for example, can be used to follow demyelination in neurodegenerative diseases or after trauma, but myelin imaging alone is not sufficient to understand the complex sequence of events that leads to the appearance of lesions in the white matter. A commercially available microendoscope is used here to achieve minimally invasive, video-rate multimodal nonlinear imaging of cellular processes in live mouse spinal cord. The system allows for simultaneous CARS imaging of myelin sheaths and two-photon excitation fluorescence microendoscopy of microglial cells and axons. Morphometric data extraction at high spatial resolution is also described, with a technique for reducing motion-related imaging artifacts. Despite its small diameter, the microendoscope enables high speed multimodal imaging over wide areas of tissue, yet at resolution sufficient to quantify subtle differences in myelin thickness and microglial motility.

Identification and High-Resolution Imaging of α-Tocopherol from Human Cells to Whole Animals by TOF-SIMS Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Bruinen, Anne L.; Fisher, Gregory L.; Balez, Rachelle; van der Sar, Astrid M.; Ooi, Lezanne; Heeren, Ron M. A.

2018-06-01

A unique method for identification of biomolecular components in different biological specimens, while preserving the capability for high speed 2D and 3D molecular imaging, is employed to investigate cellular response to oxidative stress. The employed method enables observing the distribution of the antioxidant α-tocopherol and other molecules in cellular structures via time-of-flight secondary ion mass spectrometry (TOF-SIMS (MS1)) imaging in parallel with tandem mass spectrometry (MS2) imaging, collected simultaneously. The described method is employed to examine a network formed by neuronal cells differentiated from human induced pluripotent stem cells (iPSCs), a model for investigating human neurons in vitro. The antioxidant α-tocopherol is identified in situ within different cellular layers utilizing a 3D TOF-SIMS tandem MS imaging analysis. As oxidative stress also plays an important role in mediating inflammation, the study was expanded to whole body tissue sections of M. marinum-infected zebrafish, a model organism for tuberculosis. The TOF-SIMS tandem MS imaging results reveal an increased presence of α-tocopherol in response to the pathogen. [Figure not available: see fulltext.

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.

Quantum dot tailored to single wall carbon nanotubes: a multifunctional hybrid nanoconstruct for cellular imaging and targeted photothermal therapy.

PubMed

Nair, Lakshmi V; Nagaoka, Yutaka; Maekawa, Toru; Sakthikumar, D; Jayasree, Ramapurath S

2014-07-23

Hybrid nanomaterial based on quantum dots and SWCNTs is used for cellular imaging and photothermal therapy. Furthermore, the ligand conjugated hybrid system (FaQd@CNT) enables selective targeting in cancer cells. The imaging capability of quantum dots and the therapeutic potential of SWCNT are available in a single system with cancer targeting property. Heat generated by the system is found to be high enough to destroy cancer cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly specific spectroscopic photoacoustic molecular imaging of dynamic optical absorption shifts of an antibody-ICG contrast agent (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wilson, Katheryne E.; Bachawal, Sunitha; Abou-Elkacem, Lotfi; Jensen, Kristen C.; Machtaler, Steven; Tian, Lu; Willmann, Juergen K.

2017-03-01

Improved techniques for breast cancer screening are critically needed as current methods lack diagnostic accuracy. Using spectroscopic photoacoustic (sPA) molecular imaging with a priori knowledge of optical absorption spectra allows suppression of endogenous background signal, increasing the overall sensitivity and specificity of the modality to exogenous contrast agents. Here, sPA imaging was used to monitor antibody-indocyanine green (ICG) conjugates as they undergo optical absorption spectrum shifts after cellular endocytosis and degradation to allow differentiation between normal murine mammary glands from breast cancer by enhancing molecular imaging signal from target (B7-H3)-bound antibody-ICG. First, B7-H3 was shown to have highly specific (AUC of 0.93) expression on both vascular endothelium and tumor stroma in malignant lesions through quantitative immunohistochemical staining of B7-H3 on 279 human samples (normal (n=53), benign lesions (11 subtypes, n=182), breast cancers (4 subtypes, n=97)), making B7-H3 a promising target for sPA imaging. Second, absorption spectra of intracellular and degraded B7-H3-ICG and Isotype control (Iso-ICG) were characterized through in vitro and in vivo experiments. Finally, a transgenic murine breast cancer model (FVB/N-Tg(MMTVPyMT)634Mul) was imaged, and sPA imaging in found a 3.01 (IQR 2.63, 3.38, P<0.001) fold increase in molecular B7-H3-ICG signal in tumors (n=80) compared to control conditions (B7-H3-ICG in tumor negative animals (n=60), Iso-ICG (n=30), blocking B7-H3+B7-H3-ICG (n=20), and free ICG (n=20)) despite significant tumor accumulation of Iso-ICG, confirmed through ex vivo histology. Overall, leveraging anti-B7-H3 antibody-ICG contrast agents, which have dynamic optical absorption spectra representative of molecular interactions, allows for highly specific sPA imaging of murine breast cancer.

Pulsed Magneto-motive Ultrasound Imaging Using Ultrasmall Magnetic Nanoprobes

PubMed Central

Mehrmohammadi, Mohammad; Oh, Junghwan; Mallidi, Srivalleesha; Emelianov, Stanislav Y.

2011-01-01

Nano-sized particles are widely regarded as a tool to study biologic events at the cellular and molecular levels. However, only some imaging modalities can visualize interaction between nanoparticles and living cells. We present a new technique, pulsed magneto-motive ultrasound imaging, which is capable of in vivo imaging of magnetic nanoparticles in real time and at sufficient depth. In pulsed magneto-motive ultrasound imaging, an external high-strength pulsed magnetic field is applied to induce the motion within the magnetically labeled tissue and ultrasound is used to detect the induced internal tissue motion. Our experiments demonstrated a sufficient contrast between normal and iron-laden cells labeled with ultrasmall magnetic nanoparticles. Therefore, pulsed magneto-motive ultrasound imaging could become an imaging tool capable of detecting magnetic nanoparticles and characterizing the cellular and molecular composition of deep-lying structures. PMID:21439255

A Quantitative Three-Dimensional Image Analysis Tool for Maximal Acquisition of Spatial Heterogeneity Data.

PubMed

Allenby, Mark C; Misener, Ruth; Panoskaltsis, Nicki; Mantalaris, Athanasios

2017-02-01

Three-dimensional (3D) imaging techniques provide spatial insight into environmental and cellular interactions and are implemented in various fields, including tissue engineering, but have been restricted by limited quantification tools that misrepresent or underutilize the cellular phenomena captured. This study develops image postprocessing algorithms pairing complex Euclidean metrics with Monte Carlo simulations to quantitatively assess cell and microenvironment spatial distributions while utilizing, for the first time, the entire 3D image captured. Although current methods only analyze a central fraction of presented confocal microscopy images, the proposed algorithms can utilize 210% more cells to calculate 3D spatial distributions that can span a 23-fold longer distance. These algorithms seek to leverage the high sample cost of 3D tissue imaging techniques by extracting maximal quantitative data throughout the captured image.

Portable multispectral imaging system for oral cancer diagnosis

NASA Astrophysics Data System (ADS)

Hsieh, Yao-Fang; Ou-Yang, Mang; Lee, Cheng-Chung

2013-09-01

This study presents the portable multispectral imaging system that can acquire the image of specific spectrum in vivo for oral cancer diagnosis. According to the research literature, the autofluorescence of cells and tissue have been widely applied to diagnose oral cancer. The spectral distribution is difference for lesions of epithelial cells and normal cells after excited fluorescence. We have been developed the hyperspectral and multispectral techniques for oral cancer diagnosis in three generations. This research is the third generation. The excited and emission spectrum for the diagnosis are acquired from the research of first generation. The portable system for detection of oral cancer is modified for existing handheld microscope. The UV LED is used to illuminate the surface of oral cavity and excite the cells to produce fluorescent. The image passes through the central channel and filters out unwanted spectrum by the selection of filter, and focused by the focus lens on the image sensor. Therefore, we can achieve the specific wavelength image via fluorescence reaction. The specificity and sensitivity of the system are 85% and 90%, respectively.

Brain Activation during Semantic Processing in Autism Spectrum Disorders via Functional Magnetic Resonance Imaging

ERIC Educational Resources Information Center

Harris, Gordon J.; Chabris, Christopher F.; Clark, Jill; Urban, Trinity; Aharon, Itzhak; Steele, Shelley; McGrath, Lauren; Condouris, Karen; Tager-Flusberg, Helen

2006-01-01

Language and communication deficits are core features of autism spectrum disorders (ASD), even in high-functioning adults with ASD. This study investigated brain activation patterns using functional magnetic resonance imaging in right-handed adult males with ASD and a control group, matched on age, handedness, and verbal IQ. Semantic processing in…

Tract-Specific Analyses of Diffusion Tensor Imaging Show Widespread White Matter Compromise in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Shukla, Dinesh K.; Keehn, Brandon; Muller, Ralph-Axel

2011-01-01

Background: Previous diffusion tensor imaging (DTI) studies have shown white matter compromise in children and adults with autism spectrum disorder (ASD), which may relate to reduced connectivity and impaired function of distributed networks. However, tract-specific evidence remains limited in ASD. We applied tract-based spatial statistics (TBSS)…

White Matter Compromise of Callosal and Subcortical Fiber Tracts in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

ERIC Educational Resources Information Center

Shukla, Dinesh K.; Keehn, Brandon; Lincoln, Alan J.; Muller, Ralph-Axel

2010-01-01

Objective: Autism spectrum disorder (ASD) is increasingly viewed as a disorder of functional networks, highlighting the importance of investigating white matter and interregional connectivity. We used diffusion tensor imaging (DTI) to examine white matter integrity for the whole brain and for corpus callosum, internal capsule, and middle…

Digital simulation of staining in histopathology multispectral images: enhancement and linear transformation of spectral transmittance.

PubMed

Bautista, Pinky A; Yagi, Yukako

2012-05-01

Hematoxylin and eosin (H&E) stain is currently the most popular for routine histopathology staining. Special and/or immuno-histochemical (IHC) staining is often requested to further corroborate the initial diagnosis on H&E stained tissue sections. Digital simulation of staining (or digital staining) can be a very valuable tool to produce the desired stained images from the H&E stained tissue sections instantaneously. We present an approach to digital staining of histopathology multispectral images by combining the effects of spectral enhancement and spectral transformation. Spectral enhancement is accomplished by shifting the N-band original spectrum of the multispectral pixel with the weighted difference between the pixel's original and estimated spectrum; the spectrum is estimated using M < N principal component (PC) vectors. The pixel's enhanced spectrum is transformed to the spectral configuration associated to its reaction to a specific stain by utilizing an N × N transformation matrix, which is derived through application of least mean squares method to the enhanced and target spectral transmittance samples of the different tissue components found in the image. Results of our experiments on the digital conversion of an H&E stained multispectral image to its Masson's trichrome stained equivalent show the viability of the method.

Cerebro-cerebellar Resting-State Functional Connectivity in Children and Adolescents with Autism Spectrum Disorder.

PubMed

Khan, Amanda J; Nair, Aarti; Keown, Christopher L; Datko, Michael C; Lincoln, Alan J; Müller, Ralph-Axel

2015-11-01

The cerebellum plays important roles in sensori-motor and supramodal cognitive functions. Cellular, volumetric, and functional abnormalities of the cerebellum have been found in autism spectrum disorders (ASD), but no comprehensive investigation of cerebro-cerebellar connectivity in ASD is available. We used resting-state functional connectivity magnetic resonance imaging in 56 children and adolescents (28 subjects with ASD, 28 typically developing subjects) 8-17 years old. Partial and total correlation analyses were performed for unilateral regions of interest (ROIs), distinguished in two broad domains as sensori-motor (premotor/primary motor, somatosensory, superior temporal, and occipital) and supramodal (prefrontal, posterior parietal, and inferior and middle temporal). There were three main findings: 1) Total correlation analyses showed predominant cerebro-cerebellar functional overconnectivity in the ASD group; 2) partial correlation analyses that emphasized domain specificity (sensori-motor vs. supramodal) indicated a pattern of robustly increased connectivity in the ASD group (compared with the typically developing group) for sensori-motor ROIs but predominantly reduced connectivity for supramodal ROIs; and 3) this atypical pattern of connectivity was supported by significantly increased noncanonical connections (between sensori-motor cerebral and supramodal cerebellar ROIs and vice versa) in the ASD group. Our findings indicate that sensori-motor intrinsic functional connectivity is atypically increased in ASD, at the expense of connectivity supporting cerebellar participation in supramodal cognition. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

EnLightenment: High resolution smartphone microscopy as an educational and public engagement platform.

PubMed

Wicks, Laura C; Cairns, Gemma S; Melnyk, Jacob; Bryce, Scott; Duncan, Rory R; Dalgarno, Paul A

2017-01-01

We developed a simple, cost-effective smartphone microscopy platform for use in educational and public engagement programs. We demonstrated its effectiveness, and potential for citizen science through a national imaging initiative, EnLightenment . The cost effectiveness of the instrument allowed for the program to deliver over 500 microscopes to more than 100 secondary schools throughout Scotland, targeting 1000's of 12-14 year olds. Through careful, quantified, selection of a high power, low-cost objective lens, our smartphone microscope has an imaging resolution of microns, with a working distance of 3 mm. It is therefore capable of imaging single cells and sub-cellular features, and retains usability for young children. The microscopes were designed in kit form and provided an interdisciplinary educational tool. By providing full lesson plans and support material, we developed a framework to explore optical design, microscope performance, engineering challenges on construction and real-world applications in life sciences, biological imaging, marine biology, art, and technology. A national online imaging competition framed EnLightenment ; with over 500 high quality images submitted of diverse content, spanning multiple disciplines. With examples of cellular and sub-cellular features clearly identifiable in some submissions, we show how young public can use these instruments for research-level imaging applications, and the potential of the instrument for citizen science programs.

Effect of crumb cellular structure characterized by image analysis on cake softness.

PubMed

Dewaest, Marine; Villemejane, Cindy; Berland, Sophie; Neron, Stéphane; Clement, Jérôme; Verel, Aliette; Michon, Camille

2018-06-01

Sponge cake is a cereal product characterized by an aerated crumb and appreciated for its softness. When formulating such product, it is interesting to be able to characterize the crumb structure using image analysis and to bring knowledge about the effects of the crumb cellular structure on its mechanical properties which contribute to softness. An image analysis method based on mathematical morphology was adapted from the one developed for bread crumb. In order to evaluate its ability to discriminate cellular structures, series of cakes were prepared using two rather similar emulsifiers but also using flours with different aging times before use. The mechanical properties of the crumbs of these different cakes were also characterized. It allowed a cell structure classification taking into account cell size and homogeneity, but also cell wall thickness and the number of holes in the walls. Interestingly, the cellular structure differences had a larger impact on the aerated crumb Young modulus than the wall firmness. Increasing the aging time of flour before use leads to the production of firmer crumbs due to coarser and inhomogeneous cellular structures. Changing the composition of the emulsifier may change the cellular structure and, depending on the type of the structural changes, have an impact on the firmness of the crumb. Cellular structure rather than cell wall firmness was found to impact cake crumb firmness. The new fast and automated tool for cake crumb structure analysis allows detecting quickly any change in cell size or homogeneity but also cell wall thickness and number of holes in the walls (openness degree). To obtain a softer crumb, it seems that options are to decrease the cell size and the cell wall thickness and/or to increase the openness degree. It is then possible to easily evaluate the effects of ingredients (flour composition, emulsifier …) or change in the process on the crumb structure and thus its softness. Moreover, this image analysis is a very efficient tool for quality control. © 2017 Wiley Periodicals, Inc.

Measurement of the noise power spectrum in digital x-ray detectors

NASA Astrophysics Data System (ADS)

Aufrichtig, Richard; Su, Yu; Cheng, Yu; Granfors, Paul R.

2001-06-01

The noise power spectrum, NPS, is a key imaging property of a detector and one of the principle quantities needed to compute the detective quantum efficiency. NPS is measured by computing the Fourier transform of flat field images. Different measurement methods are investigated and evaluated with images obtained from an amorphous silicon flat panel x-ray imaging detector. First, the influence of fixed pattern structures is minimized by appropriate background corrections. For a given data set the effect of using different types of windowing functions is studied. Also different window sizes and amounts of overlap between windows are evaluated and compared to theoretical predictions. Results indicate that measurement error is minimized when applying overlapping Hanning windows on the raw data. Finally it is shown that radial averaging is a useful method of reducing the two-dimensional noise power spectrum to one dimension.

Brain imaging and behavioral outcome in traumatic brain injury.

PubMed

Bigler, E D

1996-09-01

Brain imaging studies have become an essential diagnostic assessment procedure in evaluating the effects of traumatic brain injury (TBI). Such imaging studies provide a wealth of information about structural and functional deficits following TBI. But how pathologic changes identified by brain imaging methods relate to neurobehavioral outcome is not as well known. Thus, the focus of this article is on brain imaging findings and outcome following TBI. The article starts with an overview of current research dealing with the cellular pathology associated with TBI. Understanding the cellular elements of pathology permits extrapolation to what is observed with brain imaging. Next, this article reviews the relationship of brain imaging findings to underlying pathology and how that pathology relates to neurobehavioral outcome. The brain imaging techniques of magnetic resonance imaging, computerized tomography, and single photon emission computed tomography are reviewed. Various image analysis procedures, and how such findings relate to neuropsychological testing, are discussed. The importance of brain imaging in evaluating neurobehavioral deficits following brain injury is stressed.

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.

Cellular Oxygen and Nutrient Sensing in Microgravity Using Time-Resolved Fluorescence Microscopy

NASA Technical Reports Server (NTRS)

Szmacinski, Henryk

2003-01-01

Oxygen and nutrient sensing is fundamental to the understanding of cell growth and metabolism. This requires identification of optical probes and suitable detection technology without complex calibration procedures. Under this project Microcosm developed an experimental technique that allows for simultaneous imaging of intra- and inter-cellular events. The technique consists of frequency-domain Fluorescence Lifetime Imaging Microscopy (FLIM), a set of identified oxygen and pH probes, and methods for fabrication of microsensors. Specifications for electronic and optical components of FLIM instrumentation are provided. Hardware and software were developed for data acquisition and analysis. Principles, procedures, and representative images are demonstrated. Suitable lifetime sensitive oxygen, pH, and glucose probes for intra- and extra-cellular measurements of analyte concentrations have been identified and tested. Lifetime sensing and imaging have been performed using PBS buffer, culture media, and yeast cells as a model systems. Spectral specifications, calibration curves, and probes availability are also provided in the report.

A review of reagents for fluorescence microscopy of cellular compartments and structures, Part III: reagents for actin, tubulin, cellular membranes, and whole cell and cytoplasm.

PubMed

Kilgore, Jason A; Dolman, Nick J; Davidson, Michael W

2014-01-02

Non-antibody commercial fluorescent reagents for imaging of cytoskeletal structures have been limited primarily to tubulin and actin, with the main factor in choice based mainly on whether cells are live or fixed and permeabilized. A wider range of options exist for cell membrane dyes, and the choice of reagent primarily depends on the preferred localization in the cell (i.e., all membranes or only the plasma membrane) and usage (i.e., whether the protocol involves fixation and permeabilization). For whole-cell or cytoplasmic imaging, the choice of reagent is determined mostly by the length of time that the cells need to be visualized (hours or days) and by fixation status. Presented here is a discussion on choosing commercially available reagents for these cellular structures, with an emphasis on use for microscopic imaging, with a featured reagent for each structure, a recommended protocol, troubleshooting guide, and example image. Copyright © 2014 John Wiley & Sons, Inc.

Quantification of protein expression in cells and cellular subcompartments on immunohistochemical sections using a computer supported image analysis system.

PubMed

Braun, Martin; Kirsten, Robert; Rupp, Niels J; Moch, Holger; Fend, Falko; Wernert, Nicolas; Kristiansen, Glen; Perner, Sven

2013-05-01

Quantification of protein expression based on immunohistochemistry (IHC) is an important step for translational research and clinical routine. Several manual ('eyeballing') scoring systems are used in order to semi-quantify protein expression based on chromogenic intensities and distribution patterns. However, manual scoring systems are time-consuming and subject to significant intra- and interobserver variability. The aim of our study was to explore, whether new image analysis software proves to be sufficient as an alternative tool to quantify protein expression. For IHC experiments, one nucleus specific marker (i.e., ERG antibody), one cytoplasmic specific marker (i.e., SLC45A3 antibody), and one marker expressed in both compartments (i.e., TMPRSS2 antibody) were chosen. Stainings were applied on TMAs, containing tumor material of 630 prostate cancer patients. A pathologist visually quantified all IHC stainings in a blinded manner, applying a four-step scoring system. For digital quantification, image analysis software (Tissue Studio v.2.1, Definiens AG, Munich, Germany) was applied to obtain a continuous spectrum of average staining intensity. For each of the three antibodies we found a strong correlation of the manual protein expression score and the score of the image analysis software. Spearman's rank correlation coefficient was 0.94, 0.92, and 0.90 for ERG, SLC45A3, and TMPRSS2, respectively (p⟨0.01). Our data suggest that the image analysis software Tissue Studio is a powerful tool for quantification of protein expression in IHC stainings. Further, since the digital analysis is precise and reproducible, computer supported protein quantification might help to overcome intra- and interobserver variability and increase objectivity of IHC based protein assessment.

Characterizing virus-induced gene silencing at the cellular level with in situ multimodal imaging

DOE PAGES

Burkhow, Sadie J.; Stephens, Nicole M.; Mei, Yu; ...

2018-05-25

Reverse genetic strategies, such as virus-induced gene silencing, are powerful techniques to study gene function. Currently, there are few tools to study the spatial dependence of the consequences of gene silencing at the cellular level. Here, we report the use of multimodal Raman and mass spectrometry imaging to study the cellular-level biochemical changes that occur from silencing the phytoene desaturase ( pds) gene using a Foxtail mosaic virus (FoMV) vector in maize leaves. The multimodal imaging method allows the localized carotenoid distribution to be measured and reveals differences lost in the spatial average when analyzing a carotenoid extraction of themore » whole leaf. The nature of the Raman and mass spectrometry signals are complementary: silencing pds reduces the downstream carotenoid Raman signal and increases the phytoene mass spectrometry signal.« less

Characterizing virus-induced gene silencing at the cellular level with in situ multimodal imaging

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

Burkhow, Sadie J.; Stephens, Nicole M.; Mei, Yu

Reverse genetic strategies, such as virus-induced gene silencing, are powerful techniques to study gene function. Currently, there are few tools to study the spatial dependence of the consequences of gene silencing at the cellular level. Here, we report the use of multimodal Raman and mass spectrometry imaging to study the cellular-level biochemical changes that occur from silencing the phytoene desaturase ( pds) gene using a Foxtail mosaic virus (FoMV) vector in maize leaves. The multimodal imaging method allows the localized carotenoid distribution to be measured and reveals differences lost in the spatial average when analyzing a carotenoid extraction of themore » whole leaf. The nature of the Raman and mass spectrometry signals are complementary: silencing pds reduces the downstream carotenoid Raman signal and increases the phytoene mass spectrometry signal.« less

Multimodality imaging of ovarian cystic lesions: Review with an imaging based algorithmic approach

PubMed Central

Wasnik, Ashish P; Menias, Christine O; Platt, Joel F; Lalchandani, Usha R; Bedi, Deepak G; Elsayes, Khaled M

2013-01-01

Ovarian cystic masses include a spectrum of benign, borderline and high grade malignant neoplasms. Imaging plays a crucial role in characterization and pretreatment planning of incidentally detected or suspected adnexal masses, as diagnosis of ovarian malignancy at an early stage is correlated with a better prognosis. Knowledge of differential diagnosis, imaging features, management trends and an algorithmic approach of such lesions is important for optimal clinical management. This article illustrates a multi-modality approach in the diagnosis of a spectrum of ovarian cystic masses and also proposes an algorithmic approach for the diagnosis of these lesions. PMID:23671748

Estimated spectrum adaptive postfilter and the iterative prepost filtering algirighms

NASA Technical Reports Server (NTRS)

Linares, Irving (Inventor)

2004-01-01

The invention presents The Estimated Spectrum Adaptive Postfilter (ESAP) and the Iterative Prepost Filter (IPF) algorithms. These algorithms model a number of image-adaptive post-filtering and pre-post filtering methods. They are designed to minimize Discrete Cosine Transform (DCT) blocking distortion caused when images are highly compressed with the Joint Photographic Expert Group (JPEG) standard. The ESAP and the IPF techniques of the present invention minimize the mean square error (MSE) to improve the objective and subjective quality of low-bit-rate JPEG gray-scale images while simultaneously enhancing perceptual visual quality with respect to baseline JPEG images.

Reproducing the Photospheric Magnetic Field Evolution during the Rise of Cycle 24 with Flux Transport by Supergranules

NASA Technical Reports Server (NTRS)

Hathaway, David; Upton, Lisa

2012-01-01

We simulate the transport of magnetic flux in the Sun s photosphere by an evolving pattern of cellular horizontal flows (supergranules). Characteristics of the simulated flow pattern can match observed characteristics including the velocity power spectrum, cell lifetimes, and cell motions in longitude and latitude. Simulations using an average, and north-south symmetric, meridional motion of the cellular pattern produce polar magnetic fields that are too weak in the North and too strong in the South. Simulations using cellular patterns with meridional motions that evolve with the observed changes in strength and north-south asymmetry will be analyzed to see if they reproduce the polar field evolution observed during the rise of Cycle 24.

Reproducing the Photospheric Magnetic Field Evolution During the Rise of Cycle 24 with Flux Transport by Supergranules

NASA Technical Reports Server (NTRS)

Hathaway, David H.; Upton, Lisa

2012-01-01

We simulate the transport of magnetic flux in the Sun s photosphere by an evolving pattern of cellular horizontal flows (supergranules). Characteristics of the simulated flow pattern match observed characteristics including the velocity power spectrum, cell lifetimes, and cell pattern motion in longitude and latitude. Simulations using an average, and north-south symmetric, meridional motion of the cellular pattern produce polar magnetic fields that are too weak in the North and too strong in the South. Simulations using cellular patterns with meridional motions that evolve with the observed changes in strength and north-south asymmetry will be analyzed to see if they reproduce the polar field evolution observed during the rise of Cycle 24.

1024-Pixel CMOS Multimodality Joint Cellular Sensor/Stimulator Array for Real-Time Holistic Cellular Characterization and Cell-Based Drug Screening.

PubMed

Park, Jong Seok; Aziz, Moez Karim; Li, Sensen; Chi, Taiyun; Grijalva, Sandra Ivonne; Sung, Jung Hoon; Cho, Hee Cheol; Wang, Hua

2018-02-01

This paper presents a fully integrated CMOS multimodality joint sensor/stimulator array with 1024 pixels for real-time holistic cellular characterization and drug screening. The proposed system consists of four pixel groups and four parallel signal-conditioning blocks. Every pixel group contains 16 × 16 pixels, and each pixel includes one gold-plated electrode, four photodiodes, and in-pixel circuits, within a pixel footprint. Each pixel supports real-time extracellular potential recording, optical detection, charge-balanced biphasic current stimulation, and cellular impedance measurement for the same cellular sample. The proposed system is fabricated in a standard 130-nm CMOS process. Rat cardiomyocytes are successfully cultured on-chip. Measured high-resolution optical opacity images, extracellular potential recordings, biphasic current stimulations, and cellular impedance images demonstrate the unique advantages of the system for holistic cell characterization and drug screening. Furthermore, this paper demonstrates the use of optical detection on the on-chip cultured cardiomyocytes to real-time track their cyclic beating pattern and beating rate.

An unsupervised MVA method to compare specific regions in human breast tumor tissue samples using ToF-SIMS.

PubMed

Bluestein, Blake M; Morrish, Fionnuala; Graham, Daniel J; Guenthoer, Jamie; Hockenbery, David; Porter, Peggy L; Gamble, Lara J

2016-03-21

Imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal component analysis (PCA) were used to investigate two sets of pre- and post-chemotherapy human breast tumor tissue sections to characterize lipids associated with tumor metabolic flexibility and response to treatment. The micron spatial resolution imaging capability of ToF-SIMS provides a powerful approach to attain spatially-resolved molecular and cellular data from cancerous tissues not available with conventional imaging techniques. Three ca. 1 mm(2) areas per tissue section were analyzed by stitching together 200 μm × 200 μm raster area scans. A method to isolate and analyze specific tissue regions of interest by utilizing PCA of ToF-SIMS images is presented, which allowed separation of cellularized areas from stromal areas. These PCA-generated regions of interest were then used as masks to reconstruct representative spectra from specifically stromal or cellular regions. The advantage of this unsupervised selection method is a reduction in scatter in the spectral PCA results when compared to analyzing all tissue areas or analyzing areas highlighted by a pathologist. Utilizing this method, stromal and cellular regions of breast tissue biopsies taken pre- versus post-chemotherapy demonstrate chemical separation using negatively-charged ion species. In this sample set, the cellular regions were predominantly all cancer cells. Fatty acids (i.e. palmitic, oleic, and stearic), monoacylglycerols, diacylglycerols and vitamin E profiles were distinctively different between the pre- and post-therapy tissues. These results validate a new unsupervised method to isolate and interpret biochemically distinct regions in cancer tissues using imaging ToF-SIMS data. In addition, the method developed here can provide a framework to compare a variety of tissue samples using imaging ToF-SIMS, especially where there is section-to-section variability that makes it difficult to use a serial hematoxylin and eosin (H&E) stained section to direct the SIMS analysis.

Development of optical probes for in vivo imaging of polarized macrophages during foreign body reactions.

PubMed

Baker, David W; Zhou, Jun; Tsai, Yi-Ting; Patty, Kaitlen M; Weng, Hong; Tang, Ewin N; Nair, Ashwin; Hu, Wen-Jing; Tang, Liping

2014-07-01

Plasticity of macrophage (MΦ) phenotypes exist in a spectrum from classically activated (M1) cells, to alternatively activated (M2) cells, contributing to both the normal healing of tissues and the pathogenesis of implant failure. Here, folate- and mannose-based optical probes were fabricated to simultaneously determine the degree of MΦ polarization. In vitro tests show the ability of these probes to specifically target M1 and M2 cells. In an in vivo murine model, they were able to distinguish between the M1-dominated inflammatory response to infection and the M2-dominated regenerative response to particle implants. Finally, the probes were used to assess the inflammatory/regenerative properties of biomaterial implants. Our results show that these probes can be used to monitor and quantify the dynamic processes of MΦ polarization and their role in cellular responses in real time. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Spectral ophthalmoscopy based on supercontinuum

NASA Astrophysics Data System (ADS)

Cheng, Yueh-Hung; Yu, Jiun-Yann; Wu, Han-Hsuan; Huang, Bo-Jyun; Chu, Shi-Wei

2010-02-01

Confocal scanning laser ophthalmoscope (CSLO) has been established to be an important diagnostic tool for retinopathies like age-related macular degeneration, glaucoma and diabetes. Compared to a confocal laser scanning microscope, CSLO is also capable of providing optical sectioning on retina with the aid of a pinhole, but the microscope objective is replaced by the optics of eye. Since optical spectrum is the fingerprint of local chemical composition, it is attractive to incorporate spectral acquisition into CSLO. However, due to the limitation of laser bandwidth and chromatic/geometric aberration, the scanning systems in current CSLO are not compatible with spectral imaging. Here we demonstrate a spectral CSLO by combining a diffraction-limited broadband scanning system and a supercontinuum laser source. Both optical sectioning capability and sub-cellular resolution are demonstrated on zebrafish's retina. To our knowledge, it is also the first time that CSLO is applied onto the study of fish vision. The versatile spectral CSLO system will be useful to retinopathy diagnosis and neuroscience research.

NASA Tech Briefs, March 2003

NASA Technical Reports Server (NTRS)

2003-01-01

Topics covered include: Tool for Bending a Metal Tube Precisely in a Confined Space; Multiple-Use Mechanisms for Attachment to Seat Tracks; Force-Measuring Clamps; Cellular Pressure-Actuated Joint; Block QCA Fault-Tolerant Logic Gates; Hybrid VLSI/QCA Architecture for Computing FFTs; Arrays of Carbon Nanotubes as RF Filters in Waveguides; Carbon Nanotubes as Resonators for RF Spectrum Analyzers; Software for Viewing Landsat Mosaic Images; Updated Integrated Mission Program; Software for Sharing and Management of Information; Update on Integrated Optical Design Analyzer; Optical-Quality Thin Polymer Membranes; Rollable Thin Shell Composite-Material Paraboloidal Mirrors; Folded Resonant Horns for Power Ultrasonic Applications; Touchdown Ball-Bearing System for Magnetic Bearings; Flux-Based Deadbeat Control of Induction-Motor Torque; Block Copolymers as Templates for Arrays of Carbon Nanotubes; Throttling Cryogen Boiloff To Control Cryostat Temperature; Collaborative Software Development Approach Used to Deliver the New Shuttle Telemetry Ground Station; Turbulence in Supercritical O2/H2 and C7H16/N2 Mixing Layers; and Time-Resolved Measurements in Optoelectronic Microbioanal.

Dielectrophoretic spectra of single cells determined by feedback-controlled levitation.

PubMed Central

Kaler, K V; Jones, T B

1990-01-01

In this paper we have utilized the principle of dielectrophoresis (DEP) to develop an apparatus to stably levitate single biological cells using a digital feedback control scheme. Using this apparatus, the positive DEP spectra of both Canola plant protoplast and ligament fibroblast cells have been measured over a wide range of frequencies (1 kHz to 50 MHz) and suspending medium conductivities (11-800 muS/cm). The experimental data thus obtained have been interpreted in terms of a simple spherical cell model. Furthermore, utilizing such a model, we have shown that various cellular parameters of interest can be readily obtained from the measured DEP levitation spectrum. Specifically, the effective membrane capacitance of single cells has been determined. Values of 0.47 +/- 0.03 muF/cm2 for Canola protoplasts and 1.52 +/- 0.26 muF/cm2 for ligament fibroblasts thus obtained are consistent with those determined by other existing electrical methods. Images FIGURE A1 PMID:2317544

Remotely supported prehospital ultrasound: A feasibility study of real-time image transmission and expert guidance to aid diagnosis in remote and rural communities.

PubMed

Eadie, Leila; Mulhern, John; Regan, Luke; Mort, Alasdair; Shannon, Helen; Macaden, Ashish; Wilson, Philip

2017-01-01

Introduction Our aim is to expedite prehospital assessment of remote and rural patients using remotely-supported ultrasound and satellite/cellular communications. In this paradigm, paramedics are remotely-supported ultrasound operators, guided by hospital-based specialists, to record images before receiving diagnostic advice. Technology can support users in areas with little access to medical imaging and suboptimal communications coverage by connecting to multiple cellular networks and/or satellites to stream live ultrasound and audio-video. Methods An ambulance-based demonstrator system captured standard trauma and novel transcranial ultrasound scans from 10 healthy volunteers at 16 locations across the Scottish Highlands. Volunteers underwent brief scanning training before receiving expert guidance via the communications link. Ultrasound images were streamed with an audio/video feed to reviewers for interpretation. Two sessions were transmitted via satellite and 21 used cellular networks. Reviewers rated image and communication quality, and their utility for diagnosis. Transmission latency and bandwidth were recorded, and effects of scanner and reviewer experience were assessed. Results Appropriate views were provided in 94% of the simulated trauma scans. The mean upload rate was 835/150 kbps and mean latency was 114/2072 ms for cellular and satellite networks, respectively. Scanning experience had a significant impact on time to achieve a diagnostic image, and review of offline scans required significantly less time than live-streamed scans. Discussion This prehospital ultrasound system could facilitate early diagnosis and streamlining of treatment pathways for remote emergency patients, being particularly applicable in rural areas worldwide with poor communications infrastructure and extensive transport times.

Engineered ascorbate peroxidase as a genetically encoded reporter for electron microscopy.

PubMed

Martell, Jeffrey D; Deerinck, Thomas J; Sancak, Yasemin; Poulos, Thomas L; Mootha, Vamsi K; Sosinsky, Gina E; Ellisman, Mark H; Ting, Alice Y

2012-11-01

Electron microscopy (EM) is the standard method for imaging cellular structures with nanometer resolution, but existing genetic tags are inactive in most cellular compartments or require light and can be difficult to use. Here we report the development of 'APEX', a genetically encodable EM tag that is active in all cellular compartments and does not require light. APEX is a monomeric 28-kDa peroxidase that withstands strong EM fixation to give excellent ultrastructural preservation. We demonstrate the utility of APEX for high-resolution EM imaging of a variety of mammalian organelles and specific proteins using a simple and robust labeling procedure. We also fused APEX to the N or C terminus of the mitochondrial calcium uniporter (MCU), a recently identified channel whose topology is disputed. These fusions give EM contrast exclusively in the mitochondrial matrix, suggesting that both the N and C termini of MCU face the matrix. Because APEX staining is not dependent on light activation, APEX should make EM imaging of any cellular protein straightforward, regardless of the size or thickness of the specimen.

Accurate estimation of motion blur parameters in noisy remote sensing image

NASA Astrophysics Data System (ADS)

Shi, Xueyan; Wang, Lin; Shao, Xiaopeng; Wang, Huilin; Tao, Zhong

2015-05-01

The relative motion between remote sensing satellite sensor and objects is one of the most common reasons for remote sensing image degradation. It seriously weakens image data interpretation and information extraction. In practice, point spread function (PSF) should be estimated firstly for image restoration. Identifying motion blur direction and length accurately is very crucial for PSF and restoring image with precision. In general, the regular light-and-dark stripes in the spectrum can be employed to obtain the parameters by using Radon transform. However, serious noise existing in actual remote sensing images often causes the stripes unobvious. The parameters would be difficult to calculate and the error of the result relatively big. In this paper, an improved motion blur parameter identification method to noisy remote sensing image is proposed to solve this problem. The spectrum characteristic of noisy remote sensing image is analyzed firstly. An interactive image segmentation method based on graph theory called GrabCut is adopted to effectively extract the edge of the light center in the spectrum. Motion blur direction is estimated by applying Radon transform on the segmentation result. In order to reduce random error, a method based on whole column statistics is used during calculating blur length. Finally, Lucy-Richardson algorithm is applied to restore the remote sensing images of the moon after estimating blur parameters. The experimental results verify the effectiveness and robustness of our algorithm.

Exploring the feasibility of iris recognition for visible spectrum iris images obtained using smartphone camera

NASA Astrophysics Data System (ADS)

Trokielewicz, Mateusz; Bartuzi, Ewelina; Michowska, Katarzyna; Andrzejewska, Antonina; Selegrat, Monika

2015-09-01

In the age of modern, hyperconnected society that increasingly relies on mobile devices and solutions, implementing a reliable and accurate biometric system employing iris recognition presents new challenges. Typical biometric systems employing iris analysis require expensive and complicated hardware. We therefore explore an alternative way using visible spectrum iris imaging. This paper aims at answering several questions related to applying iris biometrics for images obtained in the visible spectrum using smartphone camera. Can irides be successfully and effortlessly imaged using a smartphone's built-in camera? Can existing iris recognition methods perform well when presented with such images? The main advantage of using near-infrared (NIR) illumination in dedicated iris recognition cameras is good performance almost independent of the iris color and pigmentation. Are the images obtained from smartphone's camera of sufficient quality even for the dark irides? We present experiments incorporating simple image preprocessing to find the best visibility of iris texture, followed by a performance study to assess whether iris recognition methods originally aimed at NIR iris images perform well with visible light images. To our best knowledge this is the first comprehensive analysis of iris recognition performance using a database of high-quality images collected in visible light using the smartphones flashlight together with the application of commercial off-the-shelf (COTS) iris recognition methods.

75 FR 67060 - Universal Service Reform Mobility Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-01

... CONTACT: Wireless Telecommunications Bureau, Auctions and Spectrum Access Division: Scott Mackoul at (202... the first cellular telephone licenses, the wireless industry has continually expanded and upgraded its networks to the point where third generation (called advanced or 3G) mobile wireless services are now...

Fundamental Elements in Autism: From Neurogenesis and Neurite Growth to Synaptic Plasticity

PubMed Central

Gilbert, James; Man, Heng-Ye

2017-01-01

Autism spectrum disorder (ASD) is a set of neurodevelopmental disorders with a high prevalence and impact on society. ASDs are characterized by deficits in both social behavior and cognitive function. There is a strong genetic basis underlying ASDs that is highly heterogeneous; however, multiple studies have highlighted the involvement of key processes, including neurogenesis, neurite growth, synaptogenesis and synaptic plasticity in the pathophysiology of neurodevelopmental disorders. In this review article, we focus on the major genes and signaling pathways implicated in ASD and discuss the cellular, molecular and functional studies that have shed light on common dysregulated pathways using in vitro, in vivo and human evidence. Highlights Autism spectrum disorder (ASD) has a prevalence of 1 in 68 children in the United States.ASDs are highly heterogeneous in their genetic basis.ASDs share common features at the cellular and molecular levels in the brain.Most ASD genes are implicated in neurogenesis, structural maturation, synaptogenesis and function. PMID:29209173

Inhibition-Based Biomarkers for Autism Spectrum Disorder.

PubMed

Levin, April R; Nelson, Charles A

2015-07-01

Autism spectrum disorder (ASD) is a behaviorally defined and heterogeneous disorder. Biomarkers for ASD offer the opportunity to improve prediction, diagnosis, stratification by severity and subtype, monitoring over time and in response to interventions, and overall understanding of the underlying biology of this disorder. A variety of potential biomarkers, from the level of genes and proteins to network-level interactions, is currently being examined. Many of these biomarkers relate to inhibition, which is of particular interest because in many cases ASD is thought to be a disorder of imbalance between excitation and inhibition. Abnormalities in inhibition at the cellular level lead to emergent properties in networks of neurons. These properties take into account a more complete genetic and cellular background than findings at the level of individual genes or cells, and are able to be measured in live humans, offering additional potential as diagnostic biomarkers and predictors of behaviors. In this review we provide examples of how altered inhibition may inform the search for ASD biomarkers at multiple levels, from genes to cells to networks.

Nature of the atmospheric dynamics on Venus from power spectrum analysis of Mariner 10 images

NASA Technical Reports Server (NTRS)

Travis, L. D.

1978-01-01

Power spectrum analysis of Mariner 10 images for planetary zonal wavenumbers no less than 3 and for latitudes in the range 55 deg S to 25 deg N yields spectra which show a systematic and apparently significant variation with latitude. Accordingly, average spectra are determined for three latitude zones: an equatorial region, a midlatitude region, and an intermediate zone. A comparison of the results for Venus with brightness distribution spectra for terrestrial clouds reveals similarities between the Venus midlatitude region spectrum and that for the equatorial region of the earth. The only indication of a departure from a general power law behavior for the Venus spectra is a flattening of the equatorial spectrum in the region of wavenumbers 3 and 4. The characteristics of the Venus image spectra appear to be compatible with the interpretation that the observable clouds lie in a region of high static stability with the inertial eddy motions corresponding to two-dimensional turbulence.

Simultaneous cathodoluminescence and electron microscopy cytometry of cellular vesicles labeled with fluorescent nanodiamonds

NASA Astrophysics Data System (ADS)

Nagarajan, Sounderya; Pioche-Durieu, Catherine; Tizei, Luiz H. G.; Fang, Chia-Yi; Bertrand, Jean-Rémi; Le Cam, Eric; Chang, Huan-Cheng; Treussart, François; Kociak, Mathieu

2016-06-01

Light and Transmission Electron Microscopies (LM and TEM) hold potential in bioimaging owing to the advantages of fast imaging of multiple cells with LM and ultrastructure resolution offered by TEM. Integrated or correlated LM and TEM are the current approaches to combine the advantages of both techniques. Here we propose an alternative in which the electron beam of a scanning TEM (STEM) is used to excite concomitantly the luminescence of nanoparticle labels (a process known as cathodoluminescence, CL), and image the cell ultrastructure. This CL-STEM imaging allows obtaining luminescence spectra and imaging ultrastructure simultaneously. We present a proof of principle experiment, showing the potential of this technique in image cytometry of cell vesicular components. To label the vesicles we used fluorescent diamond nanocrystals (nanodiamonds, NDs) of size ~150 nm coated with different cationic polymers, known to trigger different internalization pathways. Each polymer was associated with a type of ND with a different emission spectrum. With CL-STEM, for each individual vesicle, we were able to measure (i) their size with nanometric resolution, (ii) their content in different ND labels, and realize intracellular component cytometry. In contrast to the recently reported organelle flow cytometry technique that requires cell sonication, CL-STEM-based image cytometry preserves the cell integrity and provides a much higher resolution in size. Although this novel approach is still limited by a low throughput, the automatization of data acquisition and image analysis, combined with improved intracellular targeting, should facilitate applications in cell biology at the subcellular level.Light and Transmission Electron Microscopies (LM and TEM) hold potential in bioimaging owing to the advantages of fast imaging of multiple cells with LM and ultrastructure resolution offered by TEM. Integrated or correlated LM and TEM are the current approaches to combine the advantages of both techniques. Here we propose an alternative in which the electron beam of a scanning TEM (STEM) is used to excite concomitantly the luminescence of nanoparticle labels (a process known as cathodoluminescence, CL), and image the cell ultrastructure. This CL-STEM imaging allows obtaining luminescence spectra and imaging ultrastructure simultaneously. We present a proof of principle experiment, showing the potential of this technique in image cytometry of cell vesicular components. To label the vesicles we used fluorescent diamond nanocrystals (nanodiamonds, NDs) of size ~150 nm coated with different cationic polymers, known to trigger different internalization pathways. Each polymer was associated with a type of ND with a different emission spectrum. With CL-STEM, for each individual vesicle, we were able to measure (i) their size with nanometric resolution, (ii) their content in different ND labels, and realize intracellular component cytometry. In contrast to the recently reported organelle flow cytometry technique that requires cell sonication, CL-STEM-based image cytometry preserves the cell integrity and provides a much higher resolution in size. Although this novel approach is still limited by a low throughput, the automatization of data acquisition and image analysis, combined with improved intracellular targeting, should facilitate applications in cell biology at the subcellular level. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01908k

Abnormal Corpus Callosum Connectivity, Socio-Communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

ERIC Educational Resources Information Center

Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

2014-01-01

In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore…

Emotion Recognition in Animated Compared to Human Stimuli in Adolescents with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Brosnan, Mark; Johnson, Hilary; Grawmeyer, Beate; Chapman, Emma; Benton, Laura

2015-01-01

There is equivocal evidence as to whether there is a deficit in recognising emotional expressions in Autism spectrum disorder (ASD). This study compared emotion recognition in ASD in three types of emotion expression media (still image, dynamic image, auditory) across human stimuli (e.g. photo of a human face) and animated stimuli (e.g. cartoon…

Structural Magnetic Resonance Imaging Data Do Not Help Support DSM-5 Autism Spectrum Disorder Category

ERIC Educational Resources Information Center

Pina-Camacho, Laura; Villero, Sonia; Boada, Leticia; Fraguas, David; Janssen, Joost; Mayoral, Maria; Llorente, Cloe; Arango, Celso; Parellada, Mara

2013-01-01

This systematic review aims to determine whether or not structural magnetic resonance imaging (sMRI) data support the DSM-5 proposal of an autism spectrum disorder (ASD) diagnostic category, and whether or not classical DSM-IV autistic disorder (AD) and Asperger syndrome (AS) categories should be subsumed into it. The most replicated sMRI findings…

Horizon Detection In The Visible Spectrum

DTIC Science & Technology

2016-09-01

techniques can also recognize star patterns in star trackers for satellite attitude determination. Horizon detection in the visible spectrum was largely...discarded for attitude determination in favor of thermal imagery, due to the greater consistency of the earth’s thermal radiation. This thesis...in 85% of the tested image set. 14. SUBJECT TERMS attitude determination, machine learning, image classification, earth horizon sensor, computer

Blind beam-hardening correction from Poisson measurements

NASA Astrophysics Data System (ADS)

Gu, Renliang; Dogandžić, Aleksandar

2016-02-01

We develop a sparse image reconstruction method for Poisson-distributed polychromatic X-ray computed tomography (CT) measurements under the blind scenario where the material of the inspected object and the incident energy spectrum are unknown. We employ our mass-attenuation spectrum parameterization of the noiseless measurements and express the mass- attenuation spectrum as a linear combination of B-spline basis functions of order one. A block coordinate-descent algorithm is developed for constrained minimization of a penalized Poisson negative log-likelihood (NLL) cost function, where constraints and penalty terms ensure nonnegativity of the spline coefficients and nonnegativity and sparsity of the density map image; the image sparsity is imposed using a convex total-variation (TV) norm penalty term. This algorithm alternates between a Nesterov's proximal-gradient (NPG) step for estimating the density map image and a limited-memory Broyden-Fletcher-Goldfarb-Shanno with box constraints (L-BFGS-B) step for estimating the incident-spectrum parameters. To accelerate convergence of the density- map NPG steps, we apply function restart and a step-size selection scheme that accounts for varying local Lipschitz constants of the Poisson NLL. Real X-ray CT reconstruction examples demonstrate the performance of the proposed scheme.

Chandra X-Ray Observatory Image of Black Hole

NASA Technical Reports Server (NTRS)

2000-01-01

This Chandra X-Ray Observatory (CXO) image is a spectrum of a black hole, which is similar to the colorful spectrum of sunlight produced by a prism. The x-rays of interest are shown here recorded in bright stripes that run rightward and leftward from the center of the image. These x-rays are sorted precisely according to their energy with the highest-energy x-rays near the center of the image and the lower-energy x-rays farther out. The spectrum was obtained by using the Low Energy Transmission Grating (LETG), which intercepts x-rays and changes their direction by the amounts that depend sensitively on the x-ray energy. The assembly holds 540 gold transmission gratings. When in place behind the mirrors, the gratings intercept the x-rays reflected from the telescope. The bright spot at the center is due to a fraction of the x-ray radiation that is not deflected by the LETG. The spokes that intersect the central spot and the faint diagonal rays that flank the spectrum itself are artifacts due to the structure that supports the LETG grating elements. (Photo credit: NASA Cfa/J. McClintock et al)

Anisotropic power spectrum of refractive-index fluctuation in hypersonic turbulence.

PubMed

Li, Jiangting; Yang, Shaofei; Guo, Lixin; Cheng, Mingjian

2016-11-10

An anisotropic power spectrum of the refractive-index fluctuation in hypersonic turbulence was obtained by processing the experimental image of the hypersonic plasma sheath and transforming the generalized anisotropic von Kármán spectrum. The power spectrum suggested here can provide as good a fit to measured spectrum data for hypersonic turbulence as that recorded from the nano-planar laser scattering image. Based on the newfound anisotropic hypersonic turbulence power spectrum, Rytov approximation was employed to establish the wave structure function and the spatial coherence radius model of electromagnetic beam propagation in hypersonic turbulence. Enhancing the anisotropy characteristics of the hypersonic turbulence led to a significant improvement in the propagation performance of electromagnetic beams in hypersonic plasma sheath. The influence of hypersonic turbulence on electromagnetic beams increases with the increase of variance of the refractive-index fluctuation and the decrease of turbulence outer scale and anisotropy parameters. The spatial coherence radius was much smaller than that in atmospheric turbulence. These results are fundamental to understanding electromagnetic wave propagation in hypersonic turbulence.

In vivo reflectance confocal microscopy imaging of melanocytic skin lesions: consensus terminology glossary and illustrative images.

PubMed

Scope, Alon; Benvenuto-Andrade, Cristiane; Agero, Anna-Liza C; Malvehy, Josep; Puig, Susana; Rajadhyaksha, Milind; Busam, Klaus J; Marra, Diego E; Torres, Abel; Propperova, Iva; Langley, Richard G; Marghoob, Ashfaq A; Pellacani, Giovanni; Seidenari, Stefania; Halpern, Allan C; Gonzalez, Salvador

2007-10-01

Reflectance confocal microscopy (RCM) has been used for over 10 years for in vivo skin imaging. However, to date no standard RCM terminology has been published. To establish a glossary of terms for RCM evaluation of melanocytic lesions. Prominent RCM researchers were presented with RCM images of melanocytic lesions. Reviewers evaluated RCM images for image quality, lesion architecture, and cellular details. Reviewers could utilize published descriptors or contribute unpublished terminology to describe lesion attributes. An online meeting was conducted to reach consensus that integrates and defines existing and new RCM descriptive terms. We present a glossary with descriptors of image quality, normal skin morphology, lesion architecture, and cellular details for RCM evaluation of melanocytic lesions. Usefulness of the glossary in RCM diagnosis of melanocytic lesions needs to be assessed. Standardization of terminology is important toward implementation of RCM in the clinical setting.

Experimental approaches to identify cellular G-quadruplex structures and functions.

PubMed

Di Antonio, Marco; Rodriguez, Raphaël; Balasubramanian, Shankar

2012-05-01

Guanine-rich nucleic acids can fold into non-canonical DNA secondary structures called G-quadruplexes. The formation of these structures can interfere with the biology that is crucial to sustain cellular homeostases and metabolism via mechanisms that include transcription, translation, splicing, telomere maintenance and DNA recombination. Thus, due to their implication in several biological processes and possible role promoting genomic instability, G-quadruplex forming sequences have emerged as potential therapeutic targets. There has been a growing interest in the development of synthetic molecules and biomolecules for sensing G-quadruplex structures in cellular DNA. In this review, we summarise and discuss recent methods developed for cellular imaging of G-quadruplexes, and the application of experimental genomic approaches to detect G-quadruplexes throughout genomic DNA. In particular, we will discuss the use of engineered small molecules and natural proteins to enable pull-down, ChIP-Seq, ChIP-chip and fluorescence imaging of G-quadruplex structures in cellular DNA. Copyright © 2012 Elsevier Inc. All rights reserved.

Bioactive Potential of Marine Macroalgae from the Central Red Sea (Saudi Arabia) Assessed by High-Throughput Imaging-Based Phenotypic Profiling

PubMed Central

Kremb, Stephan; Müller, Constanze; Schmitt-Kopplin, Philippe; Voolstra, Christian R.

2017-01-01

Marine algae represent an important source of novel natural products. While their bioactive potential has been studied to some extent, limited information is available on marine algae from the Red Sea. This study aimed at the broad discovery of new bioactivities from a collection of twelve macroalgal species from the Central Red Sea. We used imaging-based High-Content Screening (HCS) with a diverse spectrum of cellular markers for detailed cytological profiling of fractionated algal extracts. The cytological profiles for 3 out of 60 algal fractions clustered closely to reference inhibitors and showed strong inhibitory activities on the HIV-1 reverse transcriptase in a single-enzyme biochemical assay, validating the suggested biological target. Subsequent chemical profiling of the active fractions of two brown algal species by ultra-high resolution mass spectrometry (FT-ICR-MS) revealed possible candidate molecules. A database query of these molecules led us to groups of compounds with structural similarities, which are suggested to be responsible for the observed activity. Our work demonstrates the versatility and power of cytological profiling for the bioprospecting of unknown biological resources and highlights Red Sea algae as a source of bioactives that may serve as a starting point for further studies. PMID:28335513

Bioactive Potential of Marine Macroalgae from the Central Red Sea (Saudi Arabia) Assessed by High-Throughput Imaging-Based Phenotypic Profiling.

PubMed

Kremb, Stephan; Müller, Constanze; Schmitt-Kopplin, Philippe; Voolstra, Christian R

2017-03-20

Marine algae represent an important source of novel natural products. While their bioactive potential has been studied to some extent, limited information is available on marine algae from the Red Sea. This study aimed at the broad discovery of new bioactivities from a collection of twelve macroalgal species from the Central Red Sea. We used imaging-based High-Content Screening (HCS) with a diverse spectrum of cellular markers for detailed cytological profiling of fractionated algal extracts. The cytological profiles for 3 out of 60 algal fractions clustered closely to reference inhibitors and showed strong inhibitory activities on the HIV-1 reverse transcriptase in a single-enzyme biochemical assay, validating the suggested biological target. Subsequent chemical profiling of the active fractions of two brown algal species by ultra-high resolution mass spectrometry (FT-ICR-MS) revealed possible candidate molecules. A database query of these molecules led us to groups of compounds with structural similarities, which are suggested to be responsible for the observed activity. Our work demonstrates the versatility and power of cytological profiling for the bioprospecting of unknown biological resources and highlights Red Sea algae as a source of bioactives that may serve as a starting point for further studies.

Quantification of substrate and cellular strains in stretchable 3D cell cultures: an experimental and computational framework.

PubMed

González-Avalos, P; Mürnseer, M; Deeg, J; Bachmann, A; Spatz, J; Dooley, S; Eils, R; Gladilin, E

2017-05-01

The mechanical cell environment is a key regulator of biological processes . In living tissues, cells are embedded into the 3D extracellular matrix and permanently exposed to mechanical forces. Quantification of the cellular strain state in a 3D matrix is therefore the first step towards understanding how physical cues determine single cell and multicellular behaviour. The majority of cell assays are, however, based on 2D cell cultures that lack many essential features of the in vivo cellular environment. Furthermore, nondestructive measurement of substrate and cellular mechanics requires appropriate computational tools for microscopic image analysis and interpretation. Here, we present an experimental and computational framework for generation and quantification of the cellular strain state in 3D cell cultures using a combination of 3D substrate stretcher, multichannel microscopic imaging and computational image analysis. The 3D substrate stretcher enables deformation of living cells embedded in bead-labelled 3D collagen hydrogels. Local substrate and cell deformations are determined by tracking displacement of fluorescent beads with subsequent finite element interpolation of cell strains over a tetrahedral tessellation. In this feasibility study, we debate diverse aspects of deformable 3D culture construction, quantification and evaluation, and present an example of its application for quantitative analysis of a cellular model system based on primary mouse hepatocytes undergoing transforming growth factor (TGF-β) induced epithelial-to-mesenchymal transition. © 2017 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.

Studies on the Mode of Action of Acifluorfen-Methyl in Nonchlorophyllous Soybean Cells 1

PubMed Central

Matringe, M.; Scalla, R.

1988-01-01

Phytotoxic effects of the herbicide acifluorfen-methyl on nonchlorophyllous soybean cells were estimated by 86Rb leakage. An action spectrum study showed maximum injury at 350 to 450 nanometers, with lesser activity between 450 and 700 nanometers. Cells treated in the dark with acifluorfen-methyl accumulated fluorescent pigments with the spectral characteristics of protoporphyrin IX. The action spectrum of acifluorfen-methyl matched the absorption spectrum of this tetrapyrrole, and the extent of cellular damage in the light was related to the degree of fluorescent pigment accumulation. We propose that the phytotoxicity of diphenyl ether herbicides could be explained by their ability to cause abnormal accumulations of tetrapyrroles, which in turn induce lethal photooxidative reactions. PMID:16665956

Label-free imaging of cellular malformation using high resolution photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Chen, Zhongjiang; Li, Bingbing; Yang, Sihua

2014-09-01

A label-free high resolution photoacoustic microscopy (PAM) system for imaging cellular malformation is presented. The carbon fibers were used to testify the lateral resolution of the PAM. Currently, the lateral resolution is better than 2.7 μm. The human normal red blood cells (RBCs) were used to prove the imaging capability of the system, and a single red blood cell was mapped with high contrast. Moreover, the iron deficiency anemia RBCs were clearly distinguished from the cell morphology by using the PAM. The experimental results demonstrate that the photoacoustic microscopy system can accomplish label-free photoacoustic imaging and that it has clinical potential for use in the detection of erythrocytes and blood vessels malformation.

Raman imaging of molecular dynamics during cellular events

NASA Astrophysics Data System (ADS)

Fujita, Katsumasa

2017-07-01

To overcome the speed limitation in Raman imaging, we have developed a microscope system that detects Raman spectra from hundreds of points in a sample simultaneously. The sample was illuminated by a line-shaped focus, and Raman scattering from the illuminated positions was measured simultaneously by an imaging spectrophotometer. We applied the line-illumination technique to observe the dynamics of intracellular molecules during cellular events. We found that intracellular cytochrome c can be clearly imaged by resonant Raman scattering. We demonstrated label-free imaging of redistribution of cytochrome c during apoptosis and osteoblastic mineralization. We also proposed alkyne-tagged Raman imaging to observe small molecules in living cells. Due to its small size and the unique Raman band, alkyne can tag molecules without strong perturbation to molecular functions and with the capability to be detected separately from endogenous molecules.

Fiber optic in vivo imaging in the mammalian nervous system

PubMed Central

Mehta, Amit D; Jung, Juergen C; Flusberg, Benjamin A; Schnitzer, Mark J

2010-01-01

The compact size, mechanical flexibility, and growing functionality of optical fiber and fiber optic devices are enabling several new modalities for imaging the mammalian nervous system in vivo. Fluorescence microendoscopy is a minimally invasive fiber modality that provides cellular resolution in deep brain areas. Diffuse optical tomography is a non-invasive modality that uses assemblies of fiber optic emitters and detectors on the cranium for volumetric imaging of brain activation. Optical coherence tomography is a sensitive interferometric imaging technique that can be implemented in a variety of fiber based formats and that might allow intrinsic optical detection of brain activity at a high resolution. Miniaturized fiber optic microscopy permits cellular level imaging in the brains of behaving animals. Together, these modalities will enable new uses of imaging in the intact nervous system for both research and clinical applications. PMID:15464896

Whole-animal imaging with high spatio-temporal resolution

NASA Astrophysics Data System (ADS)

Chhetri, Raghav; Amat, Fernando; Wan, Yinan; Höckendorf, Burkhard; Lemon, William C.; Keller, Philipp J.

2016-03-01

We developed isotropic multiview (IsoView) light-sheet microscopy in order to image fast cellular dynamics, such as cell movements in an entire developing embryo or neuronal activity throughput an entire brain or nervous system, with high resolution in all dimensions, high imaging speeds, good physical coverage and low photo-damage. To achieve high temporal resolution and high spatial resolution at the same time, IsoView microscopy rapidly images large specimens via simultaneous light-sheet illumination and fluorescence detection along four orthogonal directions. In a post-processing step, these four views are then combined by means of high-throughput multiview deconvolution to yield images with a system resolution of ≤ 450 nm in all three dimensions. Using IsoView microscopy, we performed whole-animal functional imaging of Drosophila embryos and larvae at a spatial resolution of 1.1-2.5 μm and at a temporal resolution of 2 Hz for up to 9 hours. We also performed whole-brain functional imaging in larval zebrafish and multicolor imaging of fast cellular dynamics across entire, gastrulating Drosophila embryos with isotropic, sub-cellular resolution. Compared with conventional (spatially anisotropic) light-sheet microscopy, IsoView microscopy improves spatial resolution at least sevenfold and decreases resolution anisotropy at least threefold. Compared with existing high-resolution light-sheet techniques, such as lattice lightsheet microscopy or diSPIM, IsoView microscopy effectively doubles the penetration depth and provides subsecond temporal resolution for specimens 400-fold larger than could previously be imaged.

Taxonomy of Individual Variations in Aesthetic Responses to Fractal Patterns

PubMed Central

Spehar, Branka; Walker, Nicholas; Taylor, Richard P.

2016-01-01

In two experiments, we investigate group and individual preferences in a range of different types of patterns with varying fractal-like scaling characteristics. In Experiment 1, we used 1/f filtered grayscale images as well as their thresholded (black and white) and edges only counterparts. Separate groups of observers viewed different types of images varying in slope of their amplitude spectra. Although with each image type, the groups exhibited the “universal” pattern of preference for intermediate amplitude spectrum slopes, we identified 4 distinct sub-groups in each case. Sub-group 1 exhibited a typical peak preference for intermediate amplitude spectrum slopes (“intermediate”; approx. 50%); sub-group 2 exhibited a linear increase in preference with increasing amplitude spectrum slope (“smooth”; approx. 20%), while sub-group 3 exhibited a linear decrease in preference as a function of the amplitude spectrum slope (“sharp”; approx. 20%). Sub-group 4 revealed no significant preference (“other”; approx. 10%). In Experiment 2, we extended the range of different image types and investigated preferences within the same observers. We replicate the results of our first experiment and show that individual participants exhibit stable patterns of preference across a wide range of image types. In both experiments, Q-mode factor analysis identified two principal factors that were able to explain more than 80% of interindividual variations in preference across all types of images, suggesting a highly similar dimensional structure of interindividual variations in preference for fractal-like scaling characteristics. PMID:27458365

Compact divided-pupil line-scanning confocal microscope for investigation of human tissues

NASA Astrophysics Data System (ADS)

Glazowski, Christopher; Peterson, Gary; Rajadhyaksha, Milind

2013-03-01

Divided-pupil line-scanning confocal microscopy (DPLSCM) can provide a simple and low-cost approach for imaging of human tissues with pathology-like nuclear and cellular detail. Using results from a multidimensional numerical model of DPLSCM, we found optimal pupil configurations for improved axial sectioning, as well as control of speckle noise in the case of reflectance imaging. The modeling results guided the design and construction of a simple (10 component) microscope, packaged within the footprint of an iPhone, and capable of cellular resolution. We present the optical design with experimental video-images of in-vivo human tissues.

Imaging Cellular Architecture with X-rays

PubMed Central

Larabell, Carolyn A.; Nugent, Keith A.

2012-01-01

X-ray imaging of biological samples is progressing rapidly. In this paper we review the progress to date in high resolution imaging of cellular architecture. In particular we survey the progress in soft X-ray tomography and argue that the field is coming of age and that important biological insights are starting to emerge. We then review the new ideas based on coherent diffraction. These methods are at a much earlier stage of development but, as they eliminate the need for X-ray optics, have the capacity to provide substantially better spatial resolution than zone plate based methods. PMID:20869868

Functional recognition imaging using artificial neural networks: applications to rapid cellular identification via broadband electromechanical response

NASA Astrophysics Data System (ADS)

Nikiforov, M. P.; Reukov, V. V.; Thompson, G. L.; Vertegel, A. A.; Guo, S.; Kalinin, S. V.; Jesse, S.

2009-10-01

Functional recognition imaging in scanning probe microscopy (SPM) using artificial neural network identification is demonstrated. This approach utilizes statistical analysis of complex SPM responses at a single spatial location to identify the target behavior, which is reminiscent of associative thinking in the human brain, obviating the need for analytical models. We demonstrate, as an example of recognition imaging, rapid identification of cellular organisms using the difference in electromechanical activity over a broad frequency range. Single-pixel identification of model Micrococcus lysodeikticus and Pseudomonas fluorescens bacteria is achieved, demonstrating the viability of the method.

Analysis of Students' Aptitude to Provide Meaning to Images that Represent Cellular Components at the Molecular Level

ERIC Educational Resources Information Center

Dahmani, Hassen-Reda; Schneeberger, Patricia; Kramer, IJsbrand M.

2009-01-01

The number of experimentally derived structures of cellular components is rapidly expanding, and this phenomenon is accompanied by the development of a new semiotic system for teaching. The infographic approach is shifting from a schematic toward a more realistic representation of cellular components. By realistic we mean artist-prepared or…

Using Long-Term Time-Lapse Imaging of Mammalian Cell Cycle Progression for Laboratory Instruction and Analysis

ERIC Educational Resources Information Center

Hinchcliffe, Edward H.

2005-01-01

Cinemicrography--the capture of moving cellular sequences through the microscope--has been influential in revealing the dynamic nature of cellular behavior. One of the more dramatic cellular events is mitosis, the division of sister chromatids into two daughter cells. Mitosis has been extensively studied in a variety of organisms, both…

An analytical tool that quantifies cellular morphology changes from three-dimensional fluorescence images.

PubMed

Haass-Koffler, Carolina L; Naeemuddin, Mohammad; Bartlett, Selena E

2012-08-31

The most common software analysis tools available for measuring fluorescence images are for two-dimensional (2D) data that rely on manual settings for inclusion and exclusion of data points, and computer-aided pattern recognition to support the interpretation and findings of the analysis. It has become increasingly important to be able to measure fluorescence images constructed from three-dimensional (3D) datasets in order to be able to capture the complexity of cellular dynamics and understand the basis of cellular plasticity within biological systems. Sophisticated microscopy instruments have permitted the visualization of 3D fluorescence images through the acquisition of multispectral fluorescence images and powerful analytical software that reconstructs the images from confocal stacks that then provide a 3D representation of the collected 2D images. Advanced design-based stereology methods have progressed from the approximation and assumptions of the original model-based stereology even in complex tissue sections. Despite these scientific advances in microscopy, a need remains for an automated analytic method that fully exploits the intrinsic 3D data to allow for the analysis and quantification of the complex changes in cell morphology, protein localization and receptor trafficking. Current techniques available to quantify fluorescence images include Meta-Morph (Molecular Devices, Sunnyvale, CA) and Image J (NIH) which provide manual analysis. Imaris (Andor Technology, Belfast, Northern Ireland) software provides the feature MeasurementPro, which allows the manual creation of measurement points that can be placed in a volume image or drawn on a series of 2D slices to create a 3D object. This method is useful for single-click point measurements to measure a line distance between two objects or to create a polygon that encloses a region of interest, but it is difficult to apply to complex cellular network structures. Filament Tracer (Andor) allows automatic detection of the 3D neuronal filament-like however, this module has been developed to measure defined structures such as neurons, which are comprised of dendrites, axons and spines (tree-like structure). This module has been ingeniously utilized to make morphological measurements to non-neuronal cells, however, the output data provide information of an extended cellular network by using a software that depends on a defined cell shape rather than being an amorphous-shaped cellular model. To overcome the issue of analyzing amorphous-shaped cells and making the software more suitable to a biological application, Imaris developed Imaris Cell. This was a scientific project with the Eidgenössische Technische Hochschule, which has been developed to calculate the relationship between cells and organelles. While the software enables the detection of biological constraints, by forcing one nucleus per cell and using cell membranes to segment cells, it cannot be utilized to analyze fluorescence data that are not continuous because ideally it builds cell surface without void spaces. To our knowledge, at present no user-modifiable automated approach that provides morphometric information from 3D fluorescence images has been developed that achieves cellular spatial information of an undefined shape (Figure 1). We have developed an analytical platform using the Imaris core software module and Imaris XT interfaced to MATLAB (Mat Works, Inc.). These tools allow the 3D measurement of cells without a pre-defined shape and with inconsistent fluorescence network components. Furthermore, this method will allow researchers who have extended expertise in biological systems, but not familiarity to computer applications, to perform quantification of morphological changes in cell dynamics.

Genetics Home Reference: ataxia neuropathy spectrum

MedlinePlus

... 48(3):492-501. Citation on PubMed or Free article on PubMed Central Rocher C, Taanman JW, Pierron D, Faustin B, Benard G, Rossignol R, Malgat M, Pedespan L, Letellier T. Influence of mitochondrial DNA level on cellular energy metabolism: implications for mitochondrial diseases. J Bioenerg Biomembr. ...

A novel multiphoton microscopy images segmentation method based on superpixel and watershed.

PubMed

Wu, Weilin; Lin, Jinyong; Wang, Shu; Li, Yan; Liu, Mingyu; Liu, Gaoqiang; Cai, Jianyong; Chen, Guannan; Chen, Rong

2017-04-01

Multiphoton microscopy (MPM) imaging technique based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) shows fantastic performance for biological imaging. The automatic segmentation of cellular architectural properties for biomedical diagnosis based on MPM images is still a challenging issue. A novel multiphoton microscopy images segmentation method based on superpixels and watershed (MSW) is presented here to provide good segmentation results for MPM images. The proposed method uses SLIC superpixels instead of pixels to analyze MPM images for the first time. The superpixels segmentation based on a new distance metric combined with spatial, CIE Lab color space and phase congruency features, divides the images into patches which keep the details of the cell boundaries. Then the superpixels are used to reconstruct new images by defining an average value of superpixels as image pixels intensity level. Finally, the marker-controlled watershed is utilized to segment the cell boundaries from the reconstructed images. Experimental results show that cellular boundaries can be extracted from MPM images by MSW with higher accuracy and robustness. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microscopic Imaging and Spectroscopy with Scattered Light

PubMed Central

Boustany, Nada N.; Boppart, Stephen A.; Backman, Vadim

2012-01-01

Optical contrast based on elastic scattering interactions between light and matter can be used to probe cellular structure and dynamics, and image tissue architecture. The quantitative nature and high sensitivity of light scattering signals to subtle alterations in tissue morphology, as well as the ability to visualize unstained tissue in vivo, has recently generated significant interest in optical scatter based biosensing and imaging. Here we review the fundamental methodologies used to acquire and interpret optical scatter data. We report on recent findings in this field and present current advances in optical scatter techniques and computational methods. Cellular and tissue data enabled by current advances in optical scatter spectroscopy and imaging stand to impact a variety of biomedical applications including clinical tissue diagnosis, in vivo imaging, drug discovery and basic cell biology. PMID:20617940

Multiplexed 3D FRET imaging in deep tissue of live embryos

PubMed Central

Zhao, Ming; Wan, Xiaoyang; Li, Yu; Zhou, Weibin; Peng, Leilei

2015-01-01

Current deep tissue microscopy techniques are mostly restricted to intensity mapping of fluorophores, which significantly limit their applications in investigating biochemical processes in vivo. We present a deep tissue multiplexed functional imaging method that probes multiple Förster resonant energy transfer (FRET) sensors in live embryos with high spatial resolution. The method simultaneously images fluorescence lifetimes in 3D with multiple excitation lasers. Through quantitative analysis of triple-channel intensity and lifetime images, we demonstrated that Ca2+ and cAMP levels of live embryos expressing dual FRET sensors can be monitored simultaneously at microscopic resolution. The method is compatible with a broad range of FRET sensors currently available for probing various cellular biochemical functions. It opens the door to imaging complex cellular circuitries in whole live organisms. PMID:26387920

Electrochemical imaging of cells and tissues

PubMed Central

Lin, Tzu-En; Rapino, Stefania; Girault, Hubert H.

2018-01-01

The technological and experimental progress in electrochemical imaging of biological specimens is discussed with a view on potential applications for skin cancer diagnostics, reproductive medicine and microbial testing. The electrochemical analysis of single cell activity inside cell cultures, 3D cellular aggregates and microtissues is based on the selective detection of electroactive species involved in biological functions. Electrochemical imaging strategies, based on nano/micrometric probes scanning over the sample and sensor array chips, respectively, can be made sensitive and selective without being affected by optical interference as many other microscopy techniques. The recent developments in microfabrication, electronics and cell culturing/tissue engineering have evolved in affordable and fast-sampling electrochemical imaging platforms. We believe that the topics discussed herein demonstrate the applicability of electrochemical imaging devices in many areas related to cellular functions. PMID:29899947

Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse

PubMed Central

Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

2017-01-01

Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca2+ imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca2+ imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain. PMID:28240275

Diffusion kurtosis imaging can efficiently assess the glioma grade and cellular proliferation.

PubMed

Jiang, Rifeng; Jiang, Jingjing; Zhao, Lingyun; Zhang, Jiaxuan; Zhang, Shun; Yao, Yihao; Yang, Shiqi; Shi, Jingjing; Shen, Nanxi; Su, Changliang; Zhang, Ju; Zhu, Wenzhen

2015-12-08

Conventional diffusion imaging techniques are not sufficiently accurate for evaluating glioma grade and cellular proliferation, which are critical for guiding glioma treatment. Diffusion kurtosis imaging (DKI), an advanced non-Gaussian diffusion imaging technique, has shown potential in grading glioma; however, its applications in this tumor have not been fully elucidated. In this study, DKI and diffusion weighted imaging (DWI) were performed on 74 consecutive patients with histopathologically confirmed glioma. The kurtosis and conventional diffusion metric values of the tumor were semi-automatically obtained. The relationships of these metrics with the glioma grade and Ki-67 expression were evaluated. The diagnostic efficiency of these metrics in grading was further compared. It was demonstrated that compared with the conventional diffusion metrics, the kurtosis metrics were more promising imaging markers in distinguishing high-grade from low-grade gliomas and distinguishing among grade II, III and IV gliomas; the kurtosis metrics also showed great potential in the prediction of Ki-67 expression. To our best knowledge, we are the first to reveal the ability of DKI to assess the cellular proliferation of gliomas, and to employ the semi-automatic method for the accurate measurement of gliomas. These results could have a significant impact on the diagnosis and subsequent therapy of glioma.

Correlative 3D superresolution fluorescence and electron microscopy reveal the relationship of mitochondrial nucleoids to membranes

PubMed Central

Kopek, Benjamin G.; Shtengel, Gleb; Xu, C. Shan; Clayton, David A.; Hess, Harald F.

2012-01-01

Microscopic images of specific proteins in their cellular context yield important insights into biological processes and cellular architecture. The advent of superresolution optical microscopy techniques provides the possibility to augment EM with nanometer-resolution fluorescence microscopy to access the precise location of proteins in the context of cellular ultrastructure. Unfortunately, efforts to combine superresolution fluorescence and EM have been stymied by the divergent and incompatible sample preparation protocols of the two methods. Here, we describe a protocol that preserves both the delicate photoactivatable fluorescent protein labels essential for superresolution microscopy and the fine ultrastructural context of EM. This preparation enables direct 3D imaging in 500- to 750-nm sections with interferometric photoactivatable localization microscopy followed by scanning EM images generated by focused ion beam ablation. We use this process to “colorize” detailed EM images of the mitochondrion with the position of labeled proteins. The approach presented here has provided a new level of definition of the in vivo nature of organization of mitochondrial nucleoids, and we expect this straightforward method to be applicable to many other biological questions that can be answered by direct imaging. PMID:22474357

Quantitative optical imaging of paracetamol-induced metabolism changes in the liver

NASA Astrophysics Data System (ADS)

Liang, Xiaowen; Wang, Haolu; Liu, Xin; Roberts, Michael

2016-12-01

Paracetamol is the most readily available and widely used painkiller. However, its toxicity remains the most common cause of liver injury. The toxicity of paracetamol has been attributing to its toxic metabolite, which depletes cellular glutathione (GSH) stores and reacts within cells to increase oxidative stress, leading to mitochondrial dysfunction and cell necrosis. Multiphoton microscopy (MPM) and fluorescence lifetime imaging (FLIM) can provide quantitative imaging of biological tissues and organs in vivo and allow direct visualization of cellular events, which were used to monitor cellular metabolism in paracetamol-induced toxicity in this study. To better understand mechanisms of paracetamol induced liver injury, the redox ratio of NADH/FAD in liver cells were detected and quantified by MPM imaging to represent the relative rates of glycolysis and oxidative phosphorylation within cells. Compared to normal liver, average fluorescence lifetime of NADH and redox ratio of NADH/FAD in hepatocytes was significantly decreased after paracetamol overdose for 12 and 24 hrs, reflecting impaired metabolic activity. GSH levels of treatment groups were significantly lower than those of normal livers, with gradually decreasing from periportal to centrilobular zonation. This imaging technique has significant implications for investigating metabolic mechanisms of paracetamol toxicity.

Multicolor Super-Resolution Fluorescence Imaging via Multi-Parameter Fluorophore Detection

PubMed Central

Bates, Mark; Dempsey, Graham T; Chen, Kok Hao; Zhuang, Xiaowei

2012-01-01

Understanding the complexity of the cellular environment will benefit from the ability to unambiguously resolve multiple cellular components, simultaneously and with nanometer-scale spatial resolution. Multicolor super-resolution fluorescence microscopy techniques have been developed to achieve this goal, yet challenges remain in terms of the number of targets that can be simultaneously imaged and the crosstalk between color channels. Herein, we demonstrate multicolor stochastic optical reconstruction microscopy (STORM) based on a multi-parameter detection strategy, which uses both the fluorescence activation wavelength and the emission color to discriminate between photo-activatable fluorescent probes. First, we obtained two-color super-resolution images using the near-infrared cyanine dye Alexa 750 in conjunction with a red cyanine dye Alexa 647, and quantified color crosstalk levels and image registration accuracy. Combinatorial pairing of these two switchable dyes with fluorophores which enhance photo-activation enabled multi-parameter detection of six different probes. Using this approach, we obtained six-color super-resolution fluorescence images of a model sample. The combination of multiple fluorescence detection parameters for improved fluorophore discrimination promises to substantially enhance our ability to visualize multiple cellular targets with sub-diffraction-limit resolution. PMID:22213647

Benzofurazan Sulfides for Thiol Imaging and Quantification in Live Cells through Fluorescence Microscopy

PubMed Central

Li, Yinghong; Yang, Yang; Guan, Xiangming

2012-01-01

Thiol groups play a significant role in various cellular functions. Cellular thiol concentrations can be affected by various physiological or pathological factors. A fluorescence imaging agent that can effectively and specifically image thiols in live cells through fluorescence microscopy is desirable for live cell thiol monitoring. Benzofurazan sulfides 1a–e were synthesized and found to be thiol specific fluorogenic agents except 1d. They are not fluorescent but form strong fluorescent thiol adducts after reacting with thiols through a sulfide-thiol exchange reaction. On the other hand, they exhibit no reaction with other biologically relevant nucleophilic functional groups such as -NH2, -OH, or -COOH revealing the specificity for the detection of thiols. Sulfide 1a was selected to confirm its ability to image cellular thiols through fluorescence microscopy. The compound was demonstrated to effectively image and quantify thiol changes in live cells through fluorescence microscopy using 430 nm and 520 nm as the excitation and emission wavelengths respectively. The quantification results of total thiol in live cells obtained from fluorescence microscopy were validated by an HPLC/UV total thiol assay method. The reagents and method will be of a great value to thiol redox-related research. PMID:22794193

Automatic Segmentation of High-Throughput RNAi Fluorescent Cellular Images

PubMed Central

Yan, Pingkum; Zhou, Xiaobo; Shah, Mubarak; Wong, Stephen T. C.

2010-01-01

High-throughput genome-wide RNA interference (RNAi) screening is emerging as an essential tool to assist biologists in understanding complex cellular processes. The large number of images produced in each study make manual analysis intractable; hence, automatic cellular image analysis becomes an urgent need, where segmentation is the first and one of the most important steps. In this paper, a fully automatic method for segmentation of cells from genome-wide RNAi screening images is proposed. Nuclei are first extracted from the DNA channel by using a modified watershed algorithm. Cells are then extracted by modeling the interaction between them as well as combining both gradient and region information in the Actin and Rac channels. A new energy functional is formulated based on a novel interaction model for segmenting tightly clustered cells with significant intensity variance and specific phenotypes. The energy functional is minimized by using a multiphase level set method, which leads to a highly effective cell segmentation method. Promising experimental results demonstrate that automatic segmentation of high-throughput genome-wide multichannel screening can be achieved by using the proposed method, which may also be extended to other multichannel image segmentation problems. PMID:18270043

Superresolution SAR Imaging Algorithm Based on Mvm and Weighted Norm Extrapolation

NASA Astrophysics Data System (ADS)

Zhang, P.; Chen, Q.; Li, Z.; Tang, Z.; Liu, J.; Zhao, L.

2013-08-01

In this paper, we present an extrapolation approach, which uses minimum weighted norm constraint and minimum variance spectrum estimation, for improving synthetic aperture radar (SAR) resolution. Minimum variance method is a robust high resolution method to estimate spectrum. Based on the theory of SAR imaging, the signal model of SAR imagery is analyzed to be feasible for using data extrapolation methods to improve the resolution of SAR image. The method is used to extrapolate the efficient bandwidth in phase history field and better results are obtained compared with adaptive weighted norm extrapolation (AWNE) method and traditional imaging method using simulated data and actual measured data.

EnLightenment: High resolution smartphone microscopy as an educational and public engagement platform

PubMed Central

Wicks, Laura C.; Cairns, Gemma S.; Melnyk, Jacob; Bryce, Scott; Duncan, Rory R.; Dalgarno, Paul A.

2018-01-01

We developed a simple, cost-effective smartphone microscopy platform for use in educational and public engagement programs. We demonstrated its effectiveness, and potential for citizen science through a national imaging initiative, EnLightenment. The cost effectiveness of the instrument allowed for the program to deliver over 500 microscopes to more than 100 secondary schools throughout Scotland, targeting 1000’s of 12-14 year olds. Through careful, quantified, selection of a high power, low-cost objective lens, our smartphone microscope has an imaging resolution of microns, with a working distance of 3 mm. It is therefore capable of imaging single cells and sub-cellular features, and retains usability for young children. The microscopes were designed in kit form and provided an interdisciplinary educational tool. By providing full lesson plans and support material, we developed a framework to explore optical design, microscope performance, engineering challenges on construction and real-world applications in life sciences, biological imaging, marine biology, art, and technology. A national online imaging competition framed EnLightenment ; with over 500 high quality images submitted of diverse content, spanning multiple disciplines. With examples of cellular and sub-cellular features clearly identifiable in some submissions, we show how young public can use these instruments for research-level imaging applications, and the potential of the instrument for citizen science programs. PMID:29623296

Multispectral photoacoustic characterization of ICG and porcine blood using an LED-based photoacoustic imaging system

NASA Astrophysics Data System (ADS)

Shigeta, Yusuke; Sato, Naoto; Kuniyil Ajith Singh, Mithun; Agano, Toshitaka

2018-02-01

Photoacoustic imaging is a hybrid biomedical imaging modality that has emerged over the last decade. In photoacoustic imaging, pulsed-light absorbed by the target emits ultrasound that can be detected using a conventional ultrasound array. This ultrasound data can be used to reconstruct the location and spatial details of the intrinsic/extrinsic light absorbers in the tissue. Recently we reported on the development of a multi-wavelength high frame-rate LED-based photoacoustic/ultrasound imaging system (AcousticX). In this work, we photoacoustically characterize the absorption spectrum of ICG and porcine blood using LED arrays with multiple wavelengths (405, 420, 470, 520, 620, 660, 690, 750, 810, 850, 925, 980 nm). Measurements were performed in a simple reflection mode configuration in which LED arrays where fixed on both sides of the linear array ultrasound probe. Phantom used consisted of micro-test tubes filled with ICG and porcine blood, which were placed in a tank filled with water. The photoacoustic spectrum obtained from our measurements matches well with the reference absorption spectrum. These results demonstrate the potential capability of our system in performing clinical/pre-clinical multispectral photoacoustic imaging.

Large scale superres 3D imaging: light-sheet single-molecule localization microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lu, Chieh Han; Chen, Peilin; Chen, Bi-Chang

2017-02-01

Optical imaging techniques provide much important information in understanding life science especially cellular structure and morphology because "seeing is believing". However, the resolution of optical imaging is limited by the diffraction limit, which is discovered by Ernst Abbe, i.e. λ/2(NA) (NA is the numerical aperture of the objective lens). Fluorescence super-resolution microscopic techniques such as Stimulated emission depletion microscopy (STED), Photoactivated localization microscopy (PALM), and Stochastic optical reconstruction microscopy (STORM) are invented to have the capability of seeing biological entities down to molecular level that are smaller than the diffraction limit (around 200-nm in lateral resolution). These techniques do not physically violate the Abbe limit of resolution but exploit the photoluminescence properties and labelling specificity of fluorescence molecules to achieve super-resolution imaging. However, these super-resolution techniques limit most of their applications to the 2D imaging of fixed or dead samples due to the high laser power needed or slow speed for the localization process. Extended from 2D imaging, light sheet microscopy has been proven to have a lot of applications on 3D imaging at much better spatiotemporal resolutions due to its intrinsic optical sectioning and high imaging speed. Herein, we combine the advantage of localization microscopy and light-sheet microscopy to have super-resolved cellular imaging in 3D across large field of view. With high-density labeled spontaneous blinking fluorophore and wide-field detection of light-sheet microscopy, these allow us to construct 3D super-resolution multi-cellular imaging at high speed ( minutes) by light-sheet single-molecule localization microscopy.

Optical scatter imaging of cellular and mitochondrial swelling in brain tissue models of stroke

NASA Astrophysics Data System (ADS)

Johnson, Lee James

2001-08-01

The severity of brain edema resulting from a stroke can determine a patient's survival and the extent of their recovery. Cellular swelling is the microscopic source of a significant part of brain edema. Mitochondrial swelling also appears to be a determining event in the death or survival of the cells that are injured during a stroke. Therapies for reducing brain edema are not effective in many cases and current treatments of stroke do not address mitochondrial swelling at all. This dissertation is motivated by the lack of a complete understanding of cellular swelling resulting from stroke and the lack of a good method to begin to study mitochondrial swelling resulting from stroke in living brain tissue. In this dissertation, a novel method of detecting mitochondrial and cellular swelling in living hippocampal slices is developed and validated. The system is used to obtain spatial and temporal information about cellular and mitochondrial swelling resulting from various models of stroke. The effect of changes in water content on light scatter and absorption are examined in two models of brain edema. The results of this study demonstrate that optical techniques can be used to detect changes in water content. Mie scatter theory, the theoretical basis of the dual- angle scatter ratio imaging system, is presented. Computer simulations based on Mie scatter theory are used to determine the optimal angles for imaging. A detailed account of the early systems is presented to explain the motivations for the system design, especially polarization, wavelength and light path. Mitochondrial sized latex particles are used to determine the system response to changes in scattering particle size and concentration. The dual-angle scatter ratio imaging system is used to distinguish between osmotic and excitotoxic models of stroke injury. Such distinction cannot be achieved using the current techniques to study cellular swelling in hippocampal slices. The change in the scatter ratio is then shown to correlate to mitochondrial swelling, as observed with electron microscopy. The system is finally used to study mitochondrial and cellular swelling. Evidence of the susceptibility of certain hippocampal regions, CA1 and the dentate gyrus, to exhibit mitochondrial swelling as the result of oxygen and glucose deprivation is presented. In addition, for the first time, the time course of mitochondrial swelling is seen. Finally, experiments with scatter imaging and measurement of nitric oxide with carbon fiber electrodes demonstrate a clear link between nitric oxide and cellular swelling. A potential mechanism of the action of nitric oxide is evaluated. Nitric oxide appears to act to cause cellular swelling without the release of glutamate. The use of targeted nitric oxide inhibitors may be useful for the reduction of edema.

How Adolescents with Autism Spectrum Disorder (ASD) Spontaneously Attend to Real-World Scenes: Use of a Change Blindness Paradigm

ERIC Educational Resources Information Center

Hochhauser, Michal; Aran, Adi; Grynszpan, Ouriel

2018-01-01

Visual attention of adolescents with autism spectrum disorder (ASD) was assessed using a change blindness paradigm. Twenty-five adolescents with ASD aged 12-18 years and 25 matched typically developing (TD) adolescents viewed 36 pairs of digitized real-world images. Each pair of images was displayed in a "flicker paradigm" whereby a…

Optical magnetic imaging of living cells

PubMed Central

Le Sage, D.; Arai, K.; Glenn, D. R.; DeVience, S. J.; Pham, L. M.; Rahn-Lee, L.; Lukin, M. D.; Yacoby, A.; Komeili, A.; Walsworth, R. L.

2013-01-01

Magnetic imaging is a powerful tool for probing biological and physical systems. However, existing techniques either have poor spatial resolution compared to optical microscopy and are hence not generally applicable to imaging of sub-cellular structure (e.g., magnetic resonance imaging [MRI]1), or entail operating conditions that preclude application to living biological samples while providing sub-micron resolution (e.g., scanning superconducting quantum interference device [SQUID] microscopy2, electron holography3, and magnetic resonance force microscopy [MRFM]4). Here we demonstrate magnetic imaging of living cells (magnetotactic bacteria) under ambient laboratory conditions and with sub-cellular spatial resolution (400 nm), using an optically-detected magnetic field imaging array consisting of a nanoscale layer of nitrogen-vacancy (NV) colour centres implanted at the surface of a diamond chip. With the bacteria placed on the diamond surface, we optically probe the NV quantum spin states and rapidly reconstruct images of the vector components of the magnetic field created by chains of magnetic nanoparticles (magnetosomes) produced in the bacteria, and spatially correlate these magnetic field maps with optical images acquired in the same apparatus. Wide-field sCMOS acquisition allows parallel optical and magnetic imaging of multiple cells in a population with sub-micron resolution and >100 micron field-of-view. Scanning electron microscope (SEM) images of the bacteria confirm that the correlated optical and magnetic images can be used to locate and characterize the magnetosomes in each bacterium. The results provide a new capability for imaging bio-magnetic structures in living cells under ambient conditions with high spatial resolution, and will enable the mapping of a wide range of magnetic signals within cells and cellular networks5, 6. PMID:23619694

Encoding and decoding of digital spiral imaging based on bidirectional transformation of light's spatial eigenmodes.

PubMed

Zhang, Wuhong; Chen, Lixiang

2016-06-15

Digital spiral imaging has been demonstrated as an effective optical tool to encode optical information and retrieve topographic information of an object. Here we develop a conceptually new and concise scheme for optical image encoding and decoding toward free-space digital spiral imaging. We experimentally demonstrate that the optical lattices with ℓ=±50 orbital angular momentum superpositions and a clover image with nearly 200 Laguerre-Gaussian (LG) modes can be well encoded and successfully decoded. It is found that an image encoded/decoded with a two-index LG spectrum (considering both azimuthal and radial indices, ℓ and p) possesses much higher fidelity than that with a one-index LG spectrum (only considering the ℓ index). Our work provides an alternative tool for the image encoding/decoding scheme toward free-space optical communications.

The first study on therapeutic efficacies of a vascular disrupting agent CA4P among primary hepatocellular carcinomas with a full spectrum of differentiation and vascularity: Correlation of MRI-microangiography-histopathology in rats.

PubMed

Liu, Yewei; De Keyzer, Frederik; Wang, Yixing; Wang, Fengna; Feng, Yuanbo; Chen, Feng; Yu, Jie; Liu, Jianjun; Song, Shaoli; Swinnen, Johan; Bormans, Guy; Oyen, Raymond; Huang, Gang; Ni, Yicheng

2018-04-29

To better inform the next clinical trials of vascular disrupting agent Combretastatin-A4-phosphate (CA4P) in patients with hepatic malignancies, this preclinical study aimed at evaluating CA4P therapeutic efficacy in rats with primary hepatocellular carcinomas (HCCs) of a full spectrum of differentiation and vascularity by magnetic resonance imaging (MRI), microangiography and histopathology. Ninety-six HCCs were raised in 25 rats by diethylnitrosamine gavage. Tumor growth was monitored by T2-/T1-weighted-MRI (T2WI, T1WI) using a 3.0T scanner. Early vascular response and later intratumoral necrosis were detected by dynamic-contrast-enhanced (DCE) MRI and diffusion-weighted-imaging (DWI) before, 1h and 12h after CA4P iv-administration. In-vivo MRI-findings were validated by postmortem-techniques. Multi-parametric MRI revealed rapid CA4P-induced tumor vascular shutdown within 1h, followed by variable intratumoral necrosis at 12h. Tumor volumes decreased by 10% at 1h (P<0.05), but resumed at 12h. Correlations of semi-quantitative DCE parameter initial-area-under-the-gadolinium-curve (IAUGC30) with histopathology proved partial vascular closure and compensational reopening (P<0.05). The higher grades of vascularity prevented those residual tumor tissues from CA4P-caused ischemic necrosis. By histopathology using a 4-scale cellular-differentiation criteria and a 4-grade tumor-vascularity classification, percentage of CA4P-induced necrosis negatively correlated with HCC differentiation (r=-0.404, P<0.001) and tumor vascularity (r=-0.370, P<0.001). Ordinal-logistic-regression helped to predict early tumor responses to CA4P in terms of tumoral differentiation and vascularity. This study demonstrated that CA4P could induce vascular shutdown in primary HCCs within 1h, resulting in various degrees of tumor necrosis at 12h. MRI as a real-time imaging biomarker may help to define tumor vascularity and differentiation and further to predict CA4P therapeutic outcomes. This article is protected by copyright. All rights reserved. © 2018 UICC.

Multibeam synthetic aperture radar for global oceanography

NASA Technical Reports Server (NTRS)

Jain, A.

1979-01-01

A single-frequency multibeam synthetic aperture radar concept for large swath imaging desired for global oceanography is evaluated. Each beam iilluminates a separate range and azimuth interval, and images for different beams may be separated on the basis of the Doppler spectrum of the beams or their spatial azimuth separation in the image plane of the radar processor. The azimuth resolution of the radar system is selected so that the Doppler spectrum of each beam does not interfere with the Doppler foldover due to the finite pulse repetition frequency of the radar system.

Spread spectrum phase modulation for coherent X-ray diffraction imaging.

PubMed

Zhang, Xuesong; Jiang, Jing; Xiangli, Bin; Arce, Gonzalo R

2015-09-21

High dynamic range, phase ambiguity and radiation limited resolution are three challenging issues in coherent X-ray diffraction imaging (CXDI), which limit the achievable imaging resolution. This paper proposes a spread spectrum phase modulation (SSPM) method to address the aforementioned problems in a single strobe. The requirements on phase modulator parameters are presented, and a practical implementation of SSPM is discussed via ray optics analysis. Numerical experiments demonstrate the performance of SSPM under the constraint of available X-ray optics fabrication accuracy, showing its potential to real CXDI applications.

Multimodal Brain Imaging in Autism Spectrum Disorder and the Promise of Twin Research

ERIC Educational Resources Information Center

Mevel, Katell; Fransson, Peter; Bölte, Sven

2015-01-01

Current evidence suggests the phenotype of autism spectrum disorder to be driven by a complex interaction of genetic and environmental factors impacting onto brain maturation, synaptic function, and cortical networks. However, findings are heterogeneous, and the exact neurobiological pathways of autism spectrum disorder still remain poorly…

Hyperspectral image processing methods

USDA-ARS?s Scientific Manuscript database

Hyperspectral image processing refers to the use of computer algorithms to extract, store and manipulate both spatial and spectral information contained in hyperspectral images across the visible and near-infrared portion of the electromagnetic spectrum. A typical hyperspectral image processing work...

Invisible Cirrus Clouds

NASA Technical Reports Server (NTRS)

2002-01-01

The Moderate-resolution Imaging Spectroradiometer's (MODIS') cloud detection capability is so sensitive that it can detect clouds that would be indistinguishable to the human eye. This pair of images highlights MODIS' ability to detect what scientists call 'sub-visible cirrus.' The image on top shows the scene using data collected in the visible part of the electromagnetic spectrum-the part our eyes can see. Clouds are apparent in the center and lower right of the image, while the rest of the image appears to be relatively clear. However, data collected at 1.38um (lower image) show that a thick layer of previously undetected cirrus clouds obscures the entire scene. These kinds of cirrus are called 'sub-visible' because they can't be detected using only visible light. MODIS' 1.38um channel detects electromagnetic radiation in the infrared region of the spectrum. These images were made from data collected on April 4, 2000. Image courtesy Mark Gray, MODIS Atmosphere Team

Digital image analysis agrees with visual estimates of adult bone marrow trephine biopsy cellularity.

PubMed

Hagiya, A S; Etman, A; Siddiqi, I N; Cen, S; Matcuk, G R; Brynes, R K; Salama, M E

2018-04-01

Evaluation of cellularity is an essential component of bone marrow trephine biopsy examination. The standard practice is to report the results as visual estimates (VE). Digital image analysis (DIA) offers the promise of more objective measurements of cellularity. Adult bone marrow trephine biopsy sections were assessed for cellularity by VE. Sections were scanned using an Aperio AT2 Scanscope and analyzed using a Cytonuclear (version 1.4) algorithm on halo software. Intraclass correlation (ICC) was used to assess relatedness between VE and DIA, and between MRI and DIA for a separate subset of patients. Trephine biopsy sections from a subset of patients with bone marrow biopsies uninvolved by malignancy were assessed for age-related changes. Interobserver VE agreement was good to excellent. The ICC value was 0.81 for VE and DIA, and 0.50 for MRI and DIA. Linearity studies showed no statistically significant trend for age-related changes in cellularity in our cohort (r = -.29, P = .06). Agreement was good between VE and DIA. It may be possible to use DIA or VE to measure cellularity in the appropriate clinical scenario. The limited sample size precludes similar determinations for MRI calculations. Further studies examining healthy donors are necessary before making definitive conclusions regarding age and cellularity. © 2017 John Wiley & Sons Ltd.

Design and implementation of a novel mechanical testing system for cellular solids.

PubMed

Nazarian, Ara; Stauber, Martin; Müller, Ralph

2005-05-01

Cellular solids constitute an important class of engineering materials encompassing both man-made and natural constructs. Materials such as wood, cork, coral, and cancellous bone are examples of cellular solids. The structural analysis of cellular solid failure has been limited to 2D sections to illustrate global fracture patterns. Due to the inherent destructiveness of 2D methods, dynamic assessment of fracture progression has not been possible. Image-guided failure assessment (IGFA), a noninvasive technique to analyze 3D progressive bone failure, has been developed utilizing stepwise microcompression in combination with time-lapsed microcomputed tomographic imaging (microCT). This method allows for the assessment of fracture progression in the plastic region, where much of the structural deformation/energy absorption is encountered in a cellular solid. Therefore, the goal of this project was to design and fabricate a novel micromechanical testing system to validate the effectiveness of the stepwise IGFA technique compared to classical continuous mechanical testing, using a variety of engineered and natural cellular solids. In our analysis, we found stepwise compression to be a valid approach for IGFA with high precision and accuracy comparable to classical continuous testing. Therefore, this approach complements the conventional mechanical testing methods by providing visual insight into the failure propagation mechanisms of cellular solids. (c) 2005 Wiley Periodicals, Inc.

Novel spectral imaging system combining spectroscopy with imaging applications for biology

NASA Astrophysics Data System (ADS)

Malik, Zvi; Cabib, Dario; Buckwald, Robert A.; Garini, Yuval; Soenksen, Dirk G.

1995-02-01

A novel analytical spectral-imaging system and its results in the examination of biological specimens are presented. The SpectraCube 1000 system measures the transmission, absorbance, or fluorescence spectra of images studied by light microscopy. The system is based on an interferometer combined with a CCD camera, enabling measurement of the interferogram for each pixel constructing the image. Fourier transformation of the interferograms derives pixel by pixel spectra for 170 X 170 pixels of the image. A special `similarity mapping' program has been developed, enabling comparisons of spectral algorithms of all the spatial and spectral information measured by the system in the image. By comparing the spectrum of each pixel in the specimen with a selected reference spectrum (similarity mapping), there is a depiction of the spatial distribution of macromolecules possessing the characteristics of the reference spectrum. The system has been applied to analyses of bone marrow blood cells as well as fluorescent specimens, and has revealed information which could not be unveiled by other techniques. Similarity mapping has enabled visualization of fine details of chromatin packing in the nucleus of cells and other cytoplasmic compartments. Fluorescence analysis by the system has enabled the determination of porphyrin concentrations and distribution in cytoplasmic organelles of living cells.

Impaired thalamocortical connectivity in autism spectrum disorder: a study of functional and anatomical connectivity.

PubMed

Nair, Aarti; Treiber, Jeffrey M; Shukla, Dinesh K; Shih, Patricia; Müller, Ralph-Axel

2013-06-01

The thalamus plays crucial roles in the development and mature functioning of numerous sensorimotor, cognitive and attentional circuits. Currently limited evidence suggests that autism spectrum disorder may be associated with thalamic abnormalities, potentially related to sociocommunicative and other impairments in this disorder. We used functional connectivity magnetic resonance imaging and diffusion tensor imaging probabilistic tractography to study the functional and anatomical integrity of thalamo-cortical connectivity in children and adolescents with autism spectrum disorder and matched typically developing children. For connectivity with five cortical seeds (prefontal, parieto-occipital, motor, somatosensory and temporal), we found evidence of both anatomical and functional underconnectivity. The only exception was functional connectivity with the temporal lobe, which was increased in the autism spectrum disorders group, especially in the right hemisphere. However, this effect was robust only in partial correlation analyses (partialling out time series from other cortical seeds), whereas findings from total correlation analyses suggest that temporo-thalamic overconnectivity in the autism group was only relative to the underconnectivity found for other cortical seeds. We also found evidence of microstructural compromise within the thalamic motor parcel, associated with compromise in tracts between thalamus and motor cortex, suggesting that the thalamus may play a role in motor abnormalities reported in previous autism studies. More generally, a number of correlations of diffusion tensor imaging and functional connectivity magnetic resonance imaging measures with diagnostic and neuropsychological scores indicate involvement of abnormal thalamocortical connectivity in sociocommunicative and cognitive impairments in autism spectrum disorder.

MO-DE-206-00: Joint AAPM-WMIS Symposium: Metabolic Imaging of Cancer

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

NONE

In this symposium jointly sponsored by the World Molecular Imaging Society (WMIS) and the AAPM, luminary speakers on imaging metabolism will discuss three impactful topics. The first presentation on Cellular Metabolism of FDG will be given by Guillem Pratx (Stanford). This presentation will detail new work on looking at how the most common molecular imaging agent, fluoro-deoxy-glucose is metabolized at a cellular level. This will be followed by a talk on an improved approach to whole-body PET imaging by Simon Cherry (UC Davis). Simon’s work on a new whole-body PET imaging system promises to have dramatic improvement in our abilitymore » to detect and characterize cancer using PET. Finally, Jim Bankson (MD Anderson) will discuss extremely sophisticated approaches to quantifying hyperpolarized-13-C pyruvate metabolism using MR imaging. This technology promises to compliment the exquisite sensitivity of PET with an ability to measure not just uptake, but tumor metabolism. Learning Objectives: Understand the metabolism of FDG at a cellular level. Appreciate the engineering related to a novel new high-sensitivity whole-body PET imaging system. Understand the process of hyperpolarization, how pyruvate relates to metabolism and how advanced modeling can be used to better quantify this data. G. Pratx, Funding: 5R01CA186275, 1R21CA193001, and Damon Runyon Cancer Foundation. S. Cherry, National Institutes of Health; University of California, Davis; Siemens Medical SolutionsJ. Bankson, GE Healthcare; NCI P30-CA016672; CPRIT PR140021-P5.« less

Ship detection using STFT sea background statistical modeling for large-scale oceansat remote sensing image

NASA Astrophysics Data System (ADS)

Wang, Lixia; Pei, Jihong; Xie, Weixin; Liu, Jinyuan

2018-03-01

Large-scale oceansat remote sensing images cover a big area sea surface, which fluctuation can be considered as a non-stationary process. Short-Time Fourier Transform (STFT) is a suitable analysis tool for the time varying nonstationary signal. In this paper, a novel ship detection method using 2-D STFT sea background statistical modeling for large-scale oceansat remote sensing images is proposed. First, the paper divides the large-scale oceansat remote sensing image into small sub-blocks, and 2-D STFT is applied to each sub-block individually. Second, the 2-D STFT spectrum of sub-blocks is studied and the obvious different characteristic between sea background and non-sea background is found. Finally, the statistical model for all valid frequency points in the STFT spectrum of sea background is given, and the ship detection method based on the 2-D STFT spectrum modeling is proposed. The experimental result shows that the proposed algorithm can detect ship targets with high recall rate and low missing rate.

Tumor Heterogenity Research Interactive Visualization Environment (THRIVE) | Informatics Technology for Cancer Research (ITCR)

Cancer.gov

A platform for quantitative evaluation of intratumoral spatial heterogeneity in multiplexed immunofluorescence images, via characterization of the spatial interactions between different cellular phenotypes and non-cellular constituents in the tumor microenvironment.

Genetically targeted 3D visualisation of Drosophila neurons under Electron Microscopy and X-Ray Microscopy using miniSOG

PubMed Central

Ng, Julian; Browning, Alyssa; Lechner, Lorenz; Terada, Masako; Howard, Gillian; Jefferis, Gregory S. X. E.

2016-01-01

Large dimension, high-resolution imaging is important for neural circuit visualisation as neurons have both long- and short-range patterns: from axons and dendrites to the numerous synapses at terminal endings. Electron Microscopy (EM) is the favoured approach for synaptic resolution imaging but how such structures can be segmented from high-density images within large volume datasets remains challenging. Fluorescent probes are widely used to localise synapses, identify cell-types and in tracing studies. The equivalent EM approach would benefit visualising such labelled structures from within sub-cellular, cellular, tissue and neuroanatomical contexts. Here we developed genetically-encoded, electron-dense markers using miniSOG. We demonstrate their ability in 1) labelling cellular sub-compartments of genetically-targeted neurons, 2) generating contrast under different EM modalities, and 3) segmenting labelled structures from EM volumes using computer-assisted strategies. We also tested non-destructive X-ray imaging on whole Drosophila brains to evaluate contrast staining. This enabled us to target specific regions for EM volume acquisition. PMID:27958322

Ultrahigh-resolution optical coherence elastography through a micro-endoscope: towards in vivo imaging of cellular-scale mechanics

PubMed Central

Fang, Qi; Curatolo, Andrea; Wijesinghe, Philip; Yeow, Yen Ling; Hamzah, Juliana; Noble, Peter B.; Karnowski, Karol; Sampson, David D.; Ganss, Ruth; Kim, Jun Ki; Lee, Woei M.; Kennedy, Brendan F.

2017-01-01

In this paper, we describe a technique capable of visualizing mechanical properties at the cellular scale deep in living tissue, by incorporating a gradient-index (GRIN)-lens micro-endoscope into an ultrahigh-resolution optical coherence elastography system. The optical system, after the endoscope, has a lateral resolution of 1.6 µm and an axial resolution of 2.2 µm. Bessel beam illumination and Gaussian mode detection are used to provide an extended depth-of-field of 80 µm, which is a 4-fold improvement over a fully Gaussian beam case with the same lateral resolution. Using this system, we demonstrate quantitative elasticity imaging of a soft silicone phantom containing a stiff inclusion and a freshly excised malignant murine pancreatic tumor. We also demonstrate qualitative strain imaging below the tissue surface on in situ murine muscle. The approach we introduce here can provide high-quality extended-focus images through a micro-endoscope with potential to measure cellular-scale mechanics deep in tissue. We believe this tool is promising for studying biological processes and disease progression in vivo. PMID:29188108

Classification of C2C12 cells at differentiation by convolutional neural network of deep learning using phase contrast images.

PubMed

Niioka, Hirohiko; Asatani, Satoshi; Yoshimura, Aina; Ohigashi, Hironori; Tagawa, Seiichi; Miyake, Jun

2018-01-01

In the field of regenerative medicine, tremendous numbers of cells are necessary for tissue/organ regeneration. Today automatic cell-culturing system has been developed. The next step is constructing a non-invasive method to monitor the conditions of cells automatically. As an image analysis method, convolutional neural network (CNN), one of the deep learning method, is approaching human recognition level. We constructed and applied the CNN algorithm for automatic cellular differentiation recognition of myogenic C2C12 cell line. Phase-contrast images of cultured C2C12 are prepared as input dataset. In differentiation process from myoblasts to myotubes, cellular morphology changes from round shape to elongated tubular shape due to fusion of the cells. CNN abstract the features of the shape of the cells and classify the cells depending on the culturing days from when differentiation is induced. Changes in cellular shape depending on the number of days of culture (Day 0, Day 3, Day 6) are classified with 91.3% accuracy. Image analysis with CNN has a potential to realize regenerative medicine industry.

Quantitative image analysis of cellular heterogeneity in breast tumors complements genomic profiling.

PubMed

Yuan, Yinyin; Failmezger, Henrik; Rueda, Oscar M; Ali, H Raza; Gräf, Stefan; Chin, Suet-Feung; Schwarz, Roland F; Curtis, Christina; Dunning, Mark J; Bardwell, Helen; Johnson, Nicola; Doyle, Sarah; Turashvili, Gulisa; Provenzano, Elena; Aparicio, Sam; Caldas, Carlos; Markowetz, Florian

2012-10-24

Solid tumors are heterogeneous tissues composed of a mixture of cancer and normal cells, which complicates the interpretation of their molecular profiles. Furthermore, tissue architecture is generally not reflected in molecular assays, rendering this rich information underused. To address these challenges, we developed a computational approach based on standard hematoxylin and eosin-stained tissue sections and demonstrated its power in a discovery and validation cohort of 323 and 241 breast tumors, respectively. To deconvolute cellular heterogeneity and detect subtle genomic aberrations, we introduced an algorithm based on tumor cellularity to increase the comparability of copy number profiles between samples. We next devised a predictor for survival in estrogen receptor-negative breast cancer that integrated both image-based and gene expression analyses and significantly outperformed classifiers that use single data types, such as microarray expression signatures. Image processing also allowed us to describe and validate an independent prognostic factor based on quantitative analysis of spatial patterns between stromal cells, which are not detectable by molecular assays. Our quantitative, image-based method could benefit any large-scale cancer study by refining and complementing molecular assays of tumor samples.

Single-pixel imaging based on compressive sensing with spectral-domain optical mixing

NASA Astrophysics Data System (ADS)

Zhu, Zhijing; Chi, Hao; Jin, Tao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

2017-11-01

In this letter a single-pixel imaging structure is proposed based on compressive sensing using a spatial light modulator (SLM)-based spectrum shaper. In the approach, an SLM-based spectrum shaper, the pattern of which is a predetermined pseudorandom bit sequence (PRBS), spectrally codes the optical pulse carrying image information. The energy of the spectrally mixed pulse is detected by a single-pixel photodiode and the measurement results are used to reconstruct the image via a sparse recovery algorithm. As the mixing of the image signal and the PRBS is performed in the spectral domain, optical pulse stretching, modulation, compression and synchronization in the time domain are avoided. Experiments are implemented to verify the feasibility of the approach.

Multi-scale Imaging of Cellular and Sub-cellular Structures using Scanning Probe Recognition Microscopy.

NASA Astrophysics Data System (ADS)

Chen, Q.; Rice, A. F.

2005-03-01

Scanning Probe Recognition Microscopy is a new scanning probe capability under development within our group to reliably return to and directly interact with a specific nanobiological feature of interest. In previous work, we have successfully recognized and classified tubular versus globular biological objects from experimental atomic force microscope images using a method based on normalized central moments [ref. 1]. In this paper we extend this work to include recognition schemes appropriate for cellular and sub-cellular structures. Globular cells containing tubular actin filaments are under investigation. Thus there are differences in external/internal shapes and scales. Continuous Wavelet Transform with a differential Gaussian mother wavelet is employed for multi- scale analysis. [ref. 1] Q. Chen, V. Ayres and L. Udpa, ``Biological Investigation Using Scanning Probe Recognition Microscopy,'' Proceedings 3rd IEEE Conference on Nanotechnology, vol. 2, p 863-865 (2003).

High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events

PubMed Central

Suzuki, Yuki; Sakai, Nobuaki; Yoshida, Aiko; Uekusa, Yoshitsugu; Yagi, Akira; Imaoka, Yuka; Ito, Shuichi; Karaki, Koichi; Takeyasu, Kunio

2013-01-01

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events. PMID:23823461

High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events.

PubMed

Suzuki, Yuki; Sakai, Nobuaki; Yoshida, Aiko; Uekusa, Yoshitsugu; Yagi, Akira; Imaoka, Yuka; Ito, Shuichi; Karaki, Koichi; Takeyasu, Kunio

2013-01-01

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events.

Fragile X Syndrome: An Aging Perspective

ERIC Educational Resources Information Center

Schneider, Andrea; Ligsay, Andrew; Hagerman, Randi J.

2013-01-01

Cognitive and behavioral correlates of molecular variations related to the FMR1 gene have been studied rather extensively, but research about the long-term outcome in individuals with fragile X spectrum disorders remains sparse. In this review, we present an overview of aging research and recent findings in regard to cellular and clinical…

Measuring noise equivalent irradiance of a digital short-wave infrared imaging system using a broadband source to simulate the night spectrum

NASA Astrophysics Data System (ADS)

Green, John R.; Robinson, Timothy

2015-05-01

There is a growing interest in developing helmet-mounted digital imaging systems (HMDIS) for integration into military aircraft cockpits. This interest stems from the multiple advantages of digital vs. analog imaging such as image fusion from multiple sensors, data processing to enhance the image contrast, superposition of non-imaging data over the image, and sending images to remote location for analysis. There are several properties an HMDIS must have in order to aid the pilot during night operations. In addition to the resolution, image refresh rate, dynamic range, and sensor uniformity over the entire Focal Plane Array (FPA); the imaging system must have the sensitivity to detect the limited night light available filtered through cockpit transparencies. Digital sensor sensitivity is generally measured monochromatically using a laser with a wavelength near the peak detector quantum efficiency, and is generally reported as either the Noise Equivalent Power (NEP) or Noise Equivalent Irradiance (NEI). This paper proposes a test system that measures NEI of Short-Wave Infrared (SWIR) digital imaging systems using a broadband source that simulates the night spectrum. This method has a few advantages over a monochromatic method. Namely, the test conditions provide spectrum closer to what is experienced by the end-user, and the resulting NEI may be compared directly to modeled night glow irradiance calculation. This comparison may be used to assess the Technology Readiness Level of the imaging system for the application. The test system is being developed under a Cooperative Research and Development Agreement (CRADA) with the Air Force Research Laboratory.

One-pot fabrication of high-quality InP/ZnS (core/shell) quantum dots and their application to cellular imaging.

PubMed

Hussain, Sahid; Won, Nayoun; Nam, Jutaek; Bang, Jiwon; Chung, Hyokyun; Kim, Sungjee

2009-07-13

True colors: High-quality InP and InP/ZnS quantum dots (QDs) are obtained by means of a simple one-pot method in the presence of polyethylene glycol (PEG). Rapid and size-controlled reactions lead to highly crystalline and nearly monodisperse QDs at relatively low temperatures. The particles emit from cyan blue to far-red, and are successfully used in cellular imaging (see figure).

RNA imaging: tracking in real-time RNA transport in neurons using molecular beacons and confocal microscopy.

PubMed

Zepeda, Angélica; Arias, Clorinda; Flores-Jasso, Fabian; Vaca, Luis

2013-01-01

RNAs are present within eukaryotic cells and are involved in several biological processes. RNA transport within cell compartments is important for proper cell function. To understand in depth the cellular processes in which RNA is involved requires a method that reveals RNA localization in real time in a sub-cellular context in living cells. In this protocol we describe a method for imaging RNA in living cells and in particular in neuronal cultures based on cell microinjection of molecular beacons in conjunction with confocal microscopy. This methodology overcomes some of the main obstacles for imaging RNA in live cells since microinjection allows the delivery of the probe to a desired cellular compartment and MBs bind with high specificity to its target RNA without inhibiting its function. The proper design of the MBs is essential to obtain RNA-MB association at the temperature of the cell cytosol. MBs design with other purposes in mind (such as PCR experiments) have a design that facilitates association to its target at high temperatures, rendering them unsuitable for live cell imaging. Using the methodology described in this chapter allows the study of RNA transport to different regions of neurons and may be combined with the tagging of proteins of interest to measure co-transport of the protein and the RNA to different cellular regions. Copyright © 2013 Elsevier Inc. All rights reserved.

Intelligent call admission control for multi-class services in mobile cellular networks

NASA Astrophysics Data System (ADS)

Ma, Yufeng; Hu, Xiulin; Zhang, Yunyu

2005-11-01

Scarcity of the spectrum resource and mobility of users make quality of service (QoS) provision a critical issue in mobile cellular networks. This paper presents a fuzzy call admission control scheme to meet the requirement of the QoS. A performance measure is formed as a weighted linear function of new call and handoff call blocking probabilities of each service class. Simulation compares the proposed fuzzy scheme with complete sharing and guard channel policies. Simulation results show that fuzzy scheme has a better robust performance in terms of average blocking criterion.

Strange non-chaotic attractors in a state controlled-cellular neural network-based quasiperiodically forced MLC circuit

NASA Astrophysics Data System (ADS)

Ezhilarasu, P. Megavarna; Inbavalli, M.; Murali, K.; Thamilmaran, K.

2018-07-01

In this paper, we report the dynamical transitions to strange non-chaotic attractors in a quasiperiodically forced state controlled-cellular neural network (SC-CNN)-based MLC circuit via two different mechanisms, namely the Heagy-Hammel route and the gradual fractalisation route. These transitions were observed through numerical simulations and hardware experiments and confirmed using statistical tools, such as maximal Lyapunov exponent spectrum and its variance and singular continuous spectral analysis. We find that there is a remarkable agreement of the results from both numerical simulations as well as from hardware experiments.

Inhibition of Cytosolic Phospholipase A2α Impairs an Early Step of Coronavirus Replication in Cell Culture.

PubMed

Müller, Christin; Hardt, Martin; Schwudke, Dominik; Neuman, Benjamin W; Pleschka, Stephan; Ziebuhr, John

2018-02-15

Coronavirus replication is associated with intracellular membrane rearrangements in infected cells, resulting in the formation of double-membrane vesicles (DMVs) and other membranous structures that are referred to as replicative organelles (ROs). The latter provide a structural scaffold for viral replication/transcription complexes (RTCs) and help to sequester RTC components from recognition by cellular factors involved in antiviral host responses. There is increasing evidence that plus-strand RNA (+RNA) virus replication, including RO formation and virion morphogenesis, affects cellular lipid metabolism and critically depends on enzymes involved in lipid synthesis and processing. Here, we investigated the role of cytosolic phospholipase A 2 α (cPLA 2 α) in coronavirus replication using a low-molecular-weight nonpeptidic inhibitor, pyrrolidine-2 (Py-2). The inhibition of cPLA 2 α activity, which produces lysophospholipids (LPLs) by cleaving at the sn -2 position of phospholipids, had profound effects on viral RNA and protein accumulation in human coronavirus 229E-infected Huh-7 cells. Transmission electron microscopy revealed that DMV formation in infected cells was significantly reduced in the presence of the inhibitor. Furthermore, we found that (i) viral RTCs colocalized with LPL-containing membranes, (ii) cellular LPL concentrations were increased in coronavirus-infected cells, and (iii) this increase was diminished in the presence of the cPLA 2 α inhibitor Py-2. Py-2 also displayed antiviral activities against other viruses representing the Coronaviridae and Togaviridae families, while members of the Picornaviridae were not affected. Taken together, the study provides evidence that cPLA 2 α activity is critically involved in the replication of various +RNA virus families and may thus represent a candidate target for broad-spectrum antiviral drug development. IMPORTANCE Examples of highly conserved RNA virus proteins that qualify as drug targets for broad-spectrum antivirals remain scarce, resulting in increased efforts to identify and specifically inhibit cellular functions that are essential for the replication of RNA viruses belonging to different genera and families. The present study supports and extends previous conclusions that enzymes involved in cellular lipid metabolism may be tractable targets for broad-spectrum antivirals. We obtained evidence to show that a cellular phospholipase, cPLA2α, which releases fatty acid from the sn -2 position of membrane-associated glycerophospholipids, is critically involved in coronavirus replication, most likely by producing lysophospholipids that are required to form the specialized membrane compartments in which viral RNA synthesis takes place. The importance of this enzyme in coronavirus replication and DMV formation is supported by several lines of evidence, including confocal and electron microscopy, viral replication, and lipidomics studies of coronavirus-infected cells treated with a highly specific cPLA 2 α inhibitor. Copyright © 2018 American Society for Microbiology.

Comparative Analysis of Host Cell Entry of Ebola Virus From Sierra Leone, 2014, and Zaire, 1976.

PubMed

Hofmann-Winkler, Heike; Gnirß, Kerstin; Wrensch, Florian; Pöhlmann, Stefan

2015-10-01

The ongoing Ebola virus (EBOV) disease (EVD) epidemic in Western Africa is the largest EVD outbreak recorded to date and requires the rapid development and deployment of antiviral measures. The viral glycoprotein (GP) facilitates host cell entry and, jointly with cellular interaction partners, constitutes a potential target for antiviral intervention. However, it is unknown whether the GPs of the currently and previously circulating EBOVs use the same mechanisms for cellular entry and are thus susceptible to inhibition by the same antivirals and cellular defenses. Here, we show that the GPs of the EBOVs circulating in 1976 and 2014 transduce the same spectrum of target cells, use the same cellular factors for host cell entry, and are comparably susceptible to blockade by antiviral interferon-induced transmembrane proteins and neutralizing antibody KZ52. Thus, the viruses responsible for the ongoing EVD epidemic should be fully susceptible to established antiviral strategies targeting GP and cellular entry factors. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Label-free high-throughput imaging flow cytometry

NASA Astrophysics Data System (ADS)

Mahjoubfar, A.; Chen, C.; Niazi, K. R.; Rabizadeh, S.; Jalali, B.

2014-03-01

Flow cytometry is an optical method for studying cells based on their individual physical and chemical characteristics. It is widely used in clinical diagnosis, medical research, and biotechnology for analysis of blood cells and other cells in suspension. Conventional flow cytometers aim a laser beam at a stream of cells and measure the elastic scattering of light at forward and side angles. They also perform single-point measurements of fluorescent emissions from labeled cells. However, many reagents used in cell labeling reduce cellular viability or change the behavior of the target cells through the activation of undesired cellular processes or inhibition of normal cellular activity. Therefore, labeled cells are not completely representative of their unaltered form nor are they fully reliable for downstream studies. To remove the requirement of cell labeling in flow cytometry, while still meeting the classification sensitivity and specificity goals, measurement of additional biophysical parameters is essential. Here, we introduce an interferometric imaging flow cytometer based on the world's fastest continuous-time camera. Our system simultaneously measures cellular size, scattering, and protein concentration as supplementary biophysical parameters for label-free cell classification. It exploits the wide bandwidth of ultrafast laser pulses to perform blur-free quantitative phase and intensity imaging at flow speeds as high as 10 meters per second and achieves nanometer-scale optical path length resolution for precise measurements of cellular protein concentration.

Ab initio multiple cloning simulations of pyrrole photodissociation: TKER spectra and velocity map imaging

DOE PAGES

Makhov, Dmitry V.; Saita, Kenichiro; Martinez, Todd J.; ...

2014-12-11

In this study, we report a detailed computational simulation of the photodissociation of pyrrole using the ab initio Multiple Cloning (AIMC) method implemented within MOLPRO. The efficiency of the AIMC implementation, employing train basis sets, linear approximation for matrix elements, and Ehrenfest configuration cloning, allows us to accumulate significant statistics. We calculate and analyze the total kinetic energy release (TKER) spectrum and Velocity Map Imaging (VMI) of pyrrole and compare the results directly with experimental measurements. Both the TKER spectrum and the structure of the velocity map image (VMI) are well reproduced. Previously, it has been assumed that the isotropicmore » component of the VMI arises from long time statistical dissociation. Instead, our simulations suggest that ultrafast dynamics contributes significantly to both low and high energy portions of the TKER spectrum.« less

Ab initio multiple cloning simulations of pyrrole photodissociation: TKER spectra and velocity map imaging

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

Makhov, Dmitry V.; Saita, Kenichiro; Martinez, Todd J.

In this study, we report a detailed computational simulation of the photodissociation of pyrrole using the ab initio Multiple Cloning (AIMC) method implemented within MOLPRO. The efficiency of the AIMC implementation, employing train basis sets, linear approximation for matrix elements, and Ehrenfest configuration cloning, allows us to accumulate significant statistics. We calculate and analyze the total kinetic energy release (TKER) spectrum and Velocity Map Imaging (VMI) of pyrrole and compare the results directly with experimental measurements. Both the TKER spectrum and the structure of the velocity map image (VMI) are well reproduced. Previously, it has been assumed that the isotropicmore » component of the VMI arises from long time statistical dissociation. Instead, our simulations suggest that ultrafast dynamics contributes significantly to both low and high energy portions of the TKER spectrum.« less

A Study on Cognitive Radio Coexisting with Cellular Systems

NASA Astrophysics Data System (ADS)

Tandai, Tomoya; Horiguchi, Tomoya; Deguchi, Noritaka; Tomizawa, Takeshi; Tomioka, Tazuko

Cognitive Radios (CRs) are expected to perform more significant role in the view of efficient utilization of the spectrum resources in the future wireless communication networks. In this paper, a cognitive radio coexisting with cellular systems is proposed. In the case that a cellular system adopts Frequency Division Duplex (FDD) as a multiplexing scheme, the proposed CR terminals communicate in local area on uplink channels of the cellular system with transmission powers that don't interfere with base stations of the cellular system. Alternatively, in the case that a cellular system adopts Time Division Duplex (TDD), the CR terminals communicate on uplink slots of the cellular system. However if mobile terminals in the cellular system are near the CR network, uplink signals from the mobile terminals may interfere with the CR communications. In order to avoid interference from the mobile terminals, the CR terminal performs carrier sense during a beginning part of uplink slot, and only when the level of detected signal is below a threshold, then the CR terminal transmits a signal during the remained period of the uplink slot. In this paper, both the single carrier CR network that uses one frequency channel of the cellular system and the multicarrier CR network that uses multiple frequency channels of the cellular system are considered. The probabilities of successful CR communications, the average throughputs of the CR communications according to the positions of the CR network, and the interference levels from cognitive radio network to base stations of the cellular system are evaluated in the computer simulation then the effectiveness of the proposed network is clarified.

Optical Phase Measurements of Disorder Strength Link Microstructure to Cell Stiffness.

PubMed

Eldridge, Will J; Steelman, Zachary A; Loomis, Brianna; Wax, Adam

2017-02-28

There have been sustained efforts on the part of cell biologists to understand the mechanisms by which cells respond to mechanical stimuli. To this end, many rheological tools have been developed to characterize cellular stiffness. However, measurement of cellular viscoelastic properties has been limited in scope by the nature of most microrheological methods, which require direct mechanical contact, applied at the single-cell level. In this article, we describe, to our knowledge, a new analysis approach for quantitative phase imaging that relates refractive index variance to disorder strength, a parameter that is linked to cell stiffness. Significantly, both disorder strength and cell stiffness are measured with the same phase imaging system, presenting a unique alternative for label-free, noncontact, single-shot imaging of cellular rheologic properties. To demonstrate the potential applicability of the technique, we measure phase disorder strength and shear stiffness across five cellular populations with varying mechanical properties and demonstrate an inverse relationship between these two parameters. The existence of this relationship suggests that predictions of cell mechanical properties can be obtained from examining the disorder strength of cell structure using this, to our knowledge, novel, noncontact technique. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Diagnosis of Acute Cellular Rejection Using Probe-Based Confocal Laser Endomicroscopy in Lung Transplant Recipients: a Prospective, Multicenter Trial.

PubMed

Keller, Cesar A; Khoor, Andras; Arenberg, Douglas A; Smith, Michael A; Islam, Shaheen U

2018-05-29

Acute cellular rejection (ACR) in lung transplant recipients requires demonstration of perivascular lymphocytic infiltration in alveolar tissue samples from transbronchial biopsies (TBBs). Probe-based confocal laser endomicroscopy (pCLE) allows in vivo observation of alveolar, vascular, and cellular microstructures in the lung with potential to identify ACR. The objective of our prospective, blinded, multicenter observational study was to identify pCLE findings in patients with ACR diagnosed histopathologically by TBB. Lung transplant recipients undergoing diagnostic bronchoscopies within 1 year posttransplant for suspected ACR had pCLE video imaging obtained immediately prior to tissue sampling via TBB. Findings of 2 pCLE criteria, abundant alveolar cellularity and perivascular cellularity (PVC), were assessed by 4 investigators familiar with pCLE and compared to histopathologic criteria of ACR to derive sensitivity, specificity, area under the receiver operating characteristic curve, and accuracy. Interobserver agreement was assessed by calculating intraclass coefficient and Fleiss κ. Findings were analyzed before and after a consensus meeting of investigators on interpreting images. Thirty pCLE procedures were performed on 24 patients, 8 showing ACR in TBB. Diagnostic performance and interobserver agreement using pCLE to identify PVC were significantly higher than those of abundant alveolar cellularity (P<.01). The number of blood vessels identified with PVC on pCLE was significantly correlated with histopathologic activity grading of ACR (P<.01). PVC agreement among investigators significantly improved after consensus meeting (P<.01) CONCLUSIONS: When found on pCLE, PVC is a feasible and reproducible criterion for assessment of ACR in vivo, but there is a learning curve for image interpretation.

High content cell-based assay for the inflammatory pathway

NASA Astrophysics Data System (ADS)

Mukherjee, Abhishek; Song, Joon Myong

2015-07-01

Cellular inflammation is a non-specific immune response to tissue injury that takes place via cytokine network orchestration to maintain normal tissue homeostasis. However chronic inflammation that lasts for a longer period, plays the key role in human diseases like neurodegenerative disorders and cancer development. Understanding the cellular and molecular mechanisms underlying the inflammatory pathways may be effective in targeting and modulating their outcome. Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine that effectively combines the pro-inflammatory features with the pro-apoptotic potential. Increased levels of TNF-α observed during acute and chronic inflammatory conditions are believed to induce adverse phenotypes like glucose intolerance and abnormal lipid profile. Natural products e. g., amygdalin, cinnamic acid, jasmonic acid and aspirin have proven efficacy in minimizing the TNF-α induced inflammation in vitro and in vivo. Cell lysis-free quantum dot (QDot) imaging is an emerging technique to identify the cellular mediators of a signaling cascade with a single assay in one run. In comparison to organic fluorophores, the inorganic QDots are bright, resistant to photobleaching and possess tunable optical properties that make them suitable for long term and multicolor imaging of various components in a cellular crosstalk. Hence we tested some components of the mitogen activated protein kinase (MAPK) pathway during TNF-α induced inflammation and the effects of aspirin in HepG2 cells by QDot multicolor imaging technique. Results demonstrated that aspirin showed significant protective effects against TNF-α induced cellular inflammation. The developed cell based assay paves the platform for the analysis of cellular components in a smooth and reliable way.

Optical encryption of digital data in form of quick response code using spatially incoherent illumination

NASA Astrophysics Data System (ADS)

Cheremkhin, Pavel A.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Rostislav S.

2016-11-01

Applications of optical methods for encryption purposes have been attracting interest of researchers for decades. The most popular are coherent techniques such as double random phase encoding. Its main advantage is high security due to transformation of spectrum of image to be encrypted into white spectrum via use of first phase random mask which allows for encrypted images with white spectra. Downsides are necessity of using holographic registration scheme and speckle noise occurring due to coherent illumination. Elimination of these disadvantages is possible via usage of incoherent illumination. In this case, phase registration no longer matters, which means that there is no need for holographic setup, and speckle noise is gone. Recently, encryption of digital information in form of binary images has become quite popular. Advantages of using quick response (QR) code in capacity of data container for optical encryption include: 1) any data represented as QR code will have close to white (excluding zero spatial frequency) Fourier spectrum which have good overlapping with encryption key spectrum; 2) built-in algorithm for image scale and orientation correction which simplifies decoding of decrypted QR codes; 3) embedded error correction code allows for successful decryption of information even in case of partial corruption of decrypted image. Optical encryption of digital data in form QR codes using spatially incoherent illumination was experimentally implemented. Two liquid crystal spatial light modulators were used in experimental setup for QR code and encrypting kinoform imaging respectively. Decryption was conducted digitally. Successful decryption of encrypted QR codes is demonstrated.

[Design and analysis of a novel light visible spectrum imaging spectrograph optical system].

PubMed

Shen, Man-de; Li, Fei; Zhou, Li-bing; Li, Cheng; Ren, Huan-huan; Jiang, Qing-xiu

2015-02-01

A novel visible spectrum imaging spectrograph optical system was proposed based on the negative dispersion, the arbitrary phase modulation characteristics of diffractive optical element and the aberration correction characteristics of freeform optical element. The double agglutination lens was substituted by a hybrid refractive/diffractive lens based on the negative dispersion of diffractive optical element. Two freeform optical elements were used in order to correct some aberration based on the aberration correction characteristics of freeform optical element. An example and frondose design process were presented. When the design parameters were uniform, compared with the traditional system, the novel visible spectrum imaging spectrograph optical system's weight was reduced by 22.9%, the total length was reduced by 26.6%, the maximal diameter was reduced by 30.6%, and the modulation transfer function (MTF) in 1.0 field-of-view was improved by 0.35 with field-of-view improved maximally. The maximal distortion was reduced by 1.6%, the maximal longitudinal aberration was reduced by 56.4%, and the lateral color aberration was reduced by 59. 3%. From these data, we know that the performance of the novel system was advanced quickly and it could be used to put forward a new idea for modern visible spectrum imaging spectrograph optical system design.

High resolution light-sheet based high-throughput imaging cytometry system enables visualization of intra-cellular organelles

NASA Astrophysics Data System (ADS)

Regmi, Raju; Mohan, Kavya; Mondal, Partha Pratim

2014-09-01

Visualization of intracellular organelles is achieved using a newly developed high throughput imaging cytometry system. This system interrogates the microfluidic channel using a sheet of light rather than the existing point-based scanning techniques. The advantages of the developed system are many, including, single-shot scanning of specimens flowing through the microfluidic channel at flow rate ranging from micro- to nano- lit./min. Moreover, this opens-up in-vivo imaging of sub-cellular structures and simultaneous cell counting in an imaging cytometry system. We recorded a maximum count of 2400 cells/min at a flow-rate of 700 nl/min, and simultaneous visualization of fluorescently-labeled mitochondrial network in HeLa cells during flow. The developed imaging cytometry system may find immediate application in biotechnology, fluorescence microscopy and nano-medicine.

Thiol Specific and Mitochondria Selective Fluorogenic Benzofurazan Sulfide for Live Cell Nonprotein Thiol Imaging and Quantification in Mitochondria.

PubMed

Wang, Shenggang; Yin, Huihui; Huang, Yue; Guan, Xiangming

2018-06-11

Cellular thiols are divided into two major categories: nonprotein thiols (NPSH) and protein thiols (PSH). Thiols are unevenly distributed inside the cell and compartmentalized in subcellular structures. Most of our knowledge on functions/dysfunctions of cellular/subcellular thiols is based on the quantification of cellular/subcellular thiols through homogenization of cellular/subcellular structures followed by a thiol quantification method. We would like to report a thiol-specific mitochondria-selective fluorogenic benzofurazan sulfide {7,7'-thiobis( N-rhodamine-benzo[c][1,2,5]oxadiazole-4-sulfonamide) (TBROS)} that can effectively image and quantify live cell NPSH in mitochondria through fluorescence intensity. Limited methods are available for imaging thiols in mitochondria in live cells especially in a quantitative manner. The thiol specificity of TBROS was demonstrated by its ability to react with thiols and inability to react with biologically relevant nucleophilic functional groups other than thiols. TBROS, with minimal fluorescence, formed strong fluorescent thiol adducts (λ ex = 550 nm, λ em = 580 nm) when reacting with NPSH confirming its fluorogenicity. TBROS failed to react with PSH from bovine serum albumin and cell homogenate proteins. The high mitochondrial thiol selectivity of TBROS was achieved by its mitochondria targeting structure and its higher reaction rate with NPSH at mitochondrial pH. Imaging of mitochondrial NPSH in live cells was confirmed by two colocalization methods and use of a thiol-depleting reagent. TBROS effectively imaged NPSH changes in a quantitative manner in mitochondria in live cells. The reagent will be a useful tool in exploring physiological and pathological roles of mitochondrial thiols.

Drug delivery monitoring by photoacoustic tomography with an ICG encapsulated double emulsion

NASA Astrophysics Data System (ADS)

Rajian, Justin Rajesh; Fabiilli, Mario L.; Fowlkes, J. Brian; Carson, Paul L.; Wang, Xueding

2011-07-01

The absorption spectrum of indocyanine green (ICG), a nontoxic dye used for medical diagnostics, depends upon its concentration as well as the nature of its environment, i.e., the solvent medium into which it is dissolved. In blood, ICG binds with plasma proteins, thus causing changes in its photoacoustic spectrum. We successfully encapsulated ICG in an ultrasound-triggerable perfluorocarbon double emulsion that prevents ICG from binding with plasma proteins. Photoacoustic spectral measurements on point target as well as 2-D photoacoustic images of blood vessels revealed that the photoacoustic spectrum changes significantly in blood when the ICG-loaded emulsion undergoes acoustic droplet vaporization (ADV), which is the conversion of liquid droplets into gas bubbles using ultrasound. We propose that these changes in the photoacoustic spectrum of the ICG emulsion in blood, coupled with photoacoustic tomography, could be used to spatially and quantitatively monitor ultrasound initiated drug delivery. In addition, we suggest that the photoacoustic spectral change induced by ultrasound exposure could also be used as contrast in photoacoustic imaging to obtain a background free image.

Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy.

PubMed

Rose, Jason J; Wang, Ling; Xu, Qinzi; McTiernan, Charles F; Shiva, Sruti; Tejero, Jesus; Gladwin, Mark T

2017-03-01

Carbon monoxide (CO) poisoning affects 50,000 people a year in the United States. The clinical presentation runs a spectrum, ranging from headache and dizziness to coma and death, with a mortality rate ranging from 1 to 3%. A significant number of patients who survive CO poisoning suffer from long-term neurological and affective sequelae. The neurologic deficits do not necessarily correlate with blood CO levels but likely result from the pleiotropic effects of CO on cellular mitochondrial respiration, cellular energy utilization, inflammation, and free radical generation, especially in the brain and heart. Long-term neurocognitive deficits occur in 15-40% of patients, whereas approximately one-third of moderate to severely poisoned patients exhibit cardiac dysfunction, including arrhythmia, left ventricular systolic dysfunction, and myocardial infarction. Imaging studies reveal cerebral white matter hyperintensities, with delayed posthypoxic leukoencephalopathy or diffuse brain atrophy. Management of these patients requires the identification of accompanying drug ingestions, especially in the setting of intentional poisoning, fire-related toxic gas exposures, and inhalational injuries. Conventional therapy is limited to normobaric and hyperbaric oxygen, with no available antidotal therapy. Although hyperbaric oxygen significantly reduces the permanent neurological and affective effects of CO poisoning, a portion of survivors still have substantial morbidity. There has been some early success in therapies targeting the downstream inflammatory and oxidative effects of CO poisoning. New methods to directly target the toxic effect of CO, such as CO scavenging agents, are currently under development.

Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy

PubMed Central

Xu, Qinzi; Shiva, Sruti

2017-01-01

Carbon monoxide (CO) poisoning affects 50,000 people a year in the United States. The clinical presentation runs a spectrum, ranging from headache and dizziness to coma and death, with a mortality rate ranging from 1 to 3%. A significant number of patients who survive CO poisoning suffer from long-term neurological and affective sequelae. The neurologic deficits do not necessarily correlate with blood CO levels but likely result from the pleiotropic effects of CO on cellular mitochondrial respiration, cellular energy utilization, inflammation, and free radical generation, especially in the brain and heart. Long-term neurocognitive deficits occur in 15–40% of patients, whereas approximately one-third of moderate to severely poisoned patients exhibit cardiac dysfunction, including arrhythmia, left ventricular systolic dysfunction, and myocardial infarction. Imaging studies reveal cerebral white matter hyperintensities, with delayed posthypoxic leukoencephalopathy or diffuse brain atrophy. Management of these patients requires the identification of accompanying drug ingestions, especially in the setting of intentional poisoning, fire-related toxic gas exposures, and inhalational injuries. Conventional therapy is limited to normobaric and hyperbaric oxygen, with no available antidotal therapy. Although hyperbaric oxygen significantly reduces the permanent neurological and affective effects of CO poisoning, a portion of survivors still have substantial morbidity. There has been some early success in therapies targeting the downstream inflammatory and oxidative effects of CO poisoning. New methods to directly target the toxic effect of CO, such as CO scavenging agents, are currently under development. PMID:27753502

Fast data reconstructed method of Fourier transform imaging spectrometer based on multi-core CPU

NASA Astrophysics Data System (ADS)

Yu, Chunchao; Du, Debiao; Xia, Zongze; Song, Li; Zheng, Weijian; Yan, Min; Lei, Zhenggang

2017-10-01

Imaging spectrometer can gain two-dimensional space image and one-dimensional spectrum at the same time, which shows high utility in color and spectral measurements, the true color image synthesis, military reconnaissance and so on. In order to realize the fast reconstructed processing of the Fourier transform imaging spectrometer data, the paper designed the optimization reconstructed algorithm with OpenMP parallel calculating technology, which was further used for the optimization process for the HyperSpectral Imager of `HJ-1' Chinese satellite. The results show that the method based on multi-core parallel computing technology can control the multi-core CPU hardware resources competently and significantly enhance the calculation of the spectrum reconstruction processing efficiency. If the technology is applied to more cores workstation in parallel computing, it will be possible to complete Fourier transform imaging spectrometer real-time data processing with a single computer.

Fluorescent carbohydrate probes for cell lectins

NASA Astrophysics Data System (ADS)

Galanina, Oxana; Feofanov, Alexei; Tuzikov, Alexander B.; Rapoport, Evgenia; Crocker, Paul R.; Grichine, Alexei; Egret-Charlier, Marguerite; Vigny, Paul; Le Pendu, Jacques; Bovin, Nicolai V.

2001-09-01

Fluorescein labeled carbohydrate (Glyc) probes were synthesized as analytical tools for the study of cellular lectins, i.e. SiaLe x-PAA-flu, Sia 2-PAA-flu, GlcNAc 2-PAA-flu, LacNAc-PAA-flu and a number of similar ones, with PAA a soluble polyacrylamide carrier. The binding of SiaLe x-PAA-flu was assessed using CHO cells transfected with E-selectin, and the binding of Sia 2-PAA-flu was assessed by COS cells transfected with siglec-9. In flow cytometry assays, the fluorescein probes demonstrated a specific binding to the lectin-transfected cells that was inhibited by unlabeled carbohydrate ligands. The intense binding of SiaLe x-PAA- 3H to the E-selectin transfected cells and the lack of binding to both native and permeabilized control cells lead to the conclusion that the polyacrylamide carrier itself and the spacer arm connecting the carbohydrate moiety with PAA did not contribute anymore to the binding. Tumors were obtained from nude mice by injection of CHO E-selectin or mock transfected cells. The fluorescent SiaLe x-PAA-flu probe could bind to the tumor sections from E-selectin positive CHO cells, but not from the control ones. Thus, these probes can be used to reveal specifically the carbohydrate binding sites on cells in culture as well as cells in tissue sections. The use of the confocal spectral imaging technique with Glyc-PAA-flu probes offered the unique possibility to detect lectins in different cells, even when the level of lectin expression was rather low. The confocal mode of spectrum recording provided an analysis of the probe localization with 3D submicron resolution. The spectral analysis (as a constituent part of the confocal spectral imaging technique) enabled interfering signals of the probe and intrinsic cellular fluorescence to be accurately separated, the distribution of the probe to be revealed and its local concentration to be measured.

Multibeam single frequency synthetic aperture radar processor for imaging separate range swaths

NASA Technical Reports Server (NTRS)

Jain, A. (Inventor)

1982-01-01

A single-frequency multibeam synthetic aperture radar for large swath imaging is disclosed. Each beam illuminates a separate ""footprint'' (i.e., range and azimuth interval). The distinct azimuth intervals for the separate beams produce a distinct Doppler frequency spectrum for each beam. After range correlation of raw data, an optical processor develops image data for the different beams by spatially separating the beams to place each beam of different Doppler frequency spectrum in a different location in the frequency plane as well as the imaging plane of the optical processor. Selection of a beam for imaging may be made in the frequency plane by adjusting the position of an aperture, or in the image plane by adjusting the position of a slit. The raw data may also be processed in digital form in an analogous manner.

Hypercomplex Fourier transforms of color images.

PubMed

Ell, Todd A; Sangwine, Stephen J

2007-01-01

Fourier transforms are a fundamental tool in signal and image processing, yet, until recently, there was no definition of a Fourier transform applicable to color images in a holistic manner. In this paper, hypercomplex numbers, specifically quaternions, are used to define a Fourier transform applicable to color images. The properties of the transform are developed, and it is shown that the transform may be computed using two standard complex fast Fourier transforms. The resulting spectrum is explained in terms of familiar phase and modulus concepts, and a new concept of hypercomplex axis. A method for visualizing the spectrum using color graphics is also presented. Finally, a convolution operational formula in the spectral domain is discussed.

Cell migration, intercalation and growth regulate mammalian cochlear extension.

PubMed

Driver, Elizabeth Carroll; Northrop, Amy; Kelley, Matthew W

2017-10-15

Developmental remodeling of the sensory epithelium of the cochlea is required for the formation of an elongated, tonotopically organized auditory organ, but the cellular processes that mediate these events are largely unknown. We used both morphological assessments of cellular rearrangements and time-lapse imaging to visualize cochlear remodeling in mouse. Analysis of cell redistribution showed that the cochlea extends through a combination of radial intercalation and cell growth. Live imaging demonstrated that concomitant cellular intercalation results in a brief period of epithelial convergence, although subsequent changes in cell size lead to medial-lateral spreading. Supporting cells, which retain contact with the basement membrane, exhibit biased protrusive activity and directed movement along the axis of extension. By contrast, hair cells lose contact with the basement membrane, but contribute to continued outgrowth through increased cell size. Regulation of cellular protrusions, movement and intercalation within the cochlea all require myosin II. These results establish, for the first time, many of the cellular processes that drive the distribution of sensory cells along the tonotopic axis of the cochlea. © 2017. Published by The Company of Biologists Ltd.

Brain Imaging and Behavioral Outcome in Traumatic Brain Injury.

ERIC Educational Resources Information Center

Bigler, Erin D.

1996-01-01

This review explores the cellular pathology associated with traumatic brain injury (TBI) and its relation to neurobehavioral outcomes, the relationship of brain imaging findings to underlying pathology, brain imaging techniques, various image analysis procedures and how they relate to neuropsychological testing, and the importance of brain imaging…

Rapid, low dose X-ray diffractive imaging of the malaria parasite Plasmodium falciparum.

PubMed

Jones, Michael W M; Dearnley, Megan K; van Riessen, Grant A; Abbey, Brian; Putkunz, Corey T; Junker, Mark D; Vine, David J; McNulty, Ian; Nugent, Keith A; Peele, Andrew G; Tilley, Leann

2014-08-01

Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. © 2013 Elsevier B.V. All rights reserved.

Quantitative imaging assay for NF-κB nuclear translocation in primary human macrophages

PubMed Central

Noursadeghi, Mahdad; Tsang, Jhen; Haustein, Thomas; Miller, Robert F.; Chain, Benjamin M.; Katz, David R.

2008-01-01

Quantitative measurement of NF-κB nuclear translocation is an important research tool in cellular immunology. Established methodologies have a number of limitations, such as poor sensitivity, high cost or dependence on cell lines. Novel imaging methods to measure nuclear translocation of transcriptionally active components of NF-κB are being used but are also partly limited by the need for specialist imaging equipment or image analysis software. Herein we present a method for quantitative detection of NF-κB rel A nuclear translocation, using immunofluorescence microscopy and the public domain image analysis software ImageJ that can be easily adopted for cellular immunology research without the need for specialist image analysis expertise and at low cost. The method presented here is validated by demonstrating the time course and dose response of NF-κB nuclear translocation in primary human macrophages stimulated with LPS, and by comparison with a commercial NF-κB activation reporter cell line. PMID:18036607

High speed multiphoton imaging

NASA Astrophysics Data System (ADS)

Li, Yongxiao; Brustle, Anne; Gautam, Vini; Cockburn, Ian; Gillespie, Cathy; Gaus, Katharina; Lee, Woei Ming

2016-12-01

Intravital multiphoton microscopy has emerged as a powerful technique to visualize cellular processes in-vivo. Real time processes revealed through live imaging provided many opportunities to capture cellular activities in living animals. The typical parameters that determine the performance of multiphoton microscopy are speed, field of view, 3D imaging and imaging depth; many of these are important to achieving data from in-vivo. Here, we provide a full exposition of the flexible polygon mirror based high speed laser scanning multiphoton imaging system, PCI-6110 card (National Instruments) and high speed analog frame grabber card (Matrox Solios eA/XA), which allows for rapid adjustments between frame rates i.e. 5 Hz to 50 Hz with 512 × 512 pixels. Furthermore, a motion correction algorithm is also used to mitigate motion artifacts. A customized control software called Pscan 1.0 is developed for the system. This is then followed by calibration of the imaging performance of the system and a series of quantitative in-vitro and in-vivo imaging in neuronal tissues and mice.

Large-field-of-view wide-spectrum artificial reflecting superposition compound eyes

NASA Astrophysics Data System (ADS)

Huang, Chi-Chieh

The study of the imaging principles of natural compound eyes has become an active area of research and has fueled the advancement of modern optics with many attractive design features beyond those available with conventional technologies. Most prominent among all compound eyes is the reflecting superposition compound eyes (RSCEs) found in some decapods. They are extraordinary imaging systems with numerous optical features such as minimum chromatic aberration, wide-angle field of view (FOV), high sensitivity to light and superb acuity to motion. Inspired by their remarkable visual system, we were able to implement the unique lens-free, reflection-based imaging mechanisms into a miniaturized, large-FOV optical imaging device operating at the wide visible spectrum to minimize chromatic aberration without any additional post-image processing. First, two micro-transfer printing methods, a multiple and a shear-assisted transfer printing technique, were studied and discussed to realize life-sized artificial RSCEs. The processes exploited the differential adhesive tendencies of the microstructures formed between a donor and a transfer substrate to accomplish an efficient release and transfer process. These techniques enabled conformal wrapping of three-dimensional (3-D) microstructures, initially fabricated in two-dimensional (2-D) layouts with standard fabrication technology onto a wide range of surfaces with complex and curvilinear shapes. Final part of this dissertation was focused on implementing the key operational features of the natural RSCEs into large-FOV, wide-spectrum artificial RSCEs as an optical imaging device suitable for the wide visible spectrum. Our devices can form real, clear images based on reflection rather than refraction, hence avoiding chromatic aberration due to dispersion by the optical materials. Compared to the performance of conventional refractive lenses of comparable size, our devices demonstrated minimum chromatic aberration, exceptional FOV up to 165o without distortion, modest spherical aberrations and comparable imaging quality without any post-image processing. Together with an augmenting cruciform pattern surrounding each focused image, our devices possessed enhanced, dynamic motion-tracking capability ideal for diverse applications in military, security, search and rescue, night navigation, medical imaging and astronomy. In the future, due to its reflection-based operating principles, it can be further extended into mid- and far-infrared for more demanding applications.

Cassette Series Designed for Live-Cell Imaging of Proteins and High Resolution Techniques in Yeast

PubMed Central

Young, Carissa L.; Raden, David L.; Caplan, Jeffrey; Czymmek, Kirk; Robinson, Anne S.

2012-01-01

During the past decade, it has become clear that protein function and regulation are highly dependent upon intracellular localization. Although fluorescent protein variants are ubiquitously used to monitor protein dynamics, localization, and abundance; fluorescent light microscopy techniques often lack the resolution to explore protein heterogeneity and cellular ultrastructure. Several approaches have been developed to identify, characterize, and monitor the spatial localization of proteins and complexes at the sub-organelle level; yet, many of these techniques have not been applied to yeast. Thus, we have constructed a series of cassettes containing codon-optimized epitope tags, fluorescent protein variants that cover the full spectrum of visible light, a TetCys motif used for FlAsH-based localization, and the first evaluation in yeast of a photoswitchable variant – mEos2 – to monitor discrete subpopulations of proteins via confocal microscopy. This series of modules, complete with six different selection markers, provides the optimal flexibility during live-cell imaging and multicolor labeling in vivo. Furthermore, high-resolution imaging techniques include the yeast-enhanced TetCys motif that is compatible with diaminobenzidine photooxidation used for protein localization by electron microscopy and mEos2 that is ideal for super-resolution microscopy. We have examined the utility of our cassettes by analyzing all probes fused to the C-terminus of Sec61, a polytopic membrane protein of the endoplasmic reticulum of moderate protein concentration, in order to directly compare fluorescent probes, their utility and technical applications. Our series of cassettes expand the repertoire of molecular tools available to advance targeted spatiotemporal investigations using multiple live-cell, super-resolution or electron microscopy imaging techniques. PMID:22473760

SECM half-inch tethered endoscopic capsule (HITEC) for esophageal imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kang, DongKyun; Kim, Minkyu; Carruth, Robert W.; Lu, Weina; Wu, Tao; Alali, Sanaz; Do, Dukho; Soomro, Amna R.; Grant, Catriona N.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

2016-03-01

Spectrally encoded confocal microscopy (SECM) is a high-speed confocal endomicroscopy technology that can image extremely large regions of human tissue at cellular resolution within a short imaging time. Previously, we have developed a 7-mm-diameter SECM endoscopic capsule and successfully demonstrated imaging of human esophagus in vivo. Even though we were able to successfully capture images with the previous capsule, it suffered from two limitations: (1) the capsule had a small diameter, which provided a limited contact between SECM capsule and esophagus; and (2) speckle noise in SECM images made it challenging to appreciate cellular features. In this paper, we present a new SECM capsule, termed SECM half-inch tethered endoscopic capsule (HITEC), which addresses the two aforementioned technical challenges. With the SECM HITEC, a dual-clad fiber was used to reduce the speckle noise. Miniature GRIN optics was used to increase the NA of the fiber from 0.09 to 0.25, which made it possible to build a SECM capsule with large diameter (12.7 mm) while maintaining a short rigid length (22 mm). A water-immersion objective lens was custom designed and manufactured to provide high NA of 0.7. We have manufactured the SECM HITEC catheter and tested its optical and mechanical performance. Lateral and axial resolution was measured as 1.2 µm and 13 µm, respectively. We have imaged swine esophageal tissues ex vivo, and SECM images clearly visualized cell nuclei. Non-uniform rotational distortion (NURD) was small, less than 5%. Preliminary results suggest that SECM HITEC provides sufficient optical and mechanical performance for tissue imaging. In a future clinical study, we will test the feasibility of utilizing SECM HITEC for improved cellular imaging human of the human esophagus in vivo.

Non-contact full-field optical coherence tomography: a novel tool for in vivo imaging of the human cornea (Conference Presentation)

NASA Astrophysics Data System (ADS)

Mazlin, Viacheslav; Dalimier, Eugénie; Grieve, Katharine F.; Irsch, Kristina; Sahel, José-Alain; Fink, Mathias; Boccara, A. Claude

2017-02-01

According to the World Health Organization (WHO), corneal diseases alongside with cataract and retinal diseases are major causes of blindness worldwide. For the 95.5% of corneal blindness cases, prevention or rehabilitation could have been possible without negative consequences for vision, provided that disease is diagnosed early. However, diagnostics at the early stage requires cellular-level resolution, which is not achieved with routinely used Slit-lamp and OCT instruments. Confocal microscopy allows examination of the cornea at a resolution approaching histological detail, however requires contact with a patient's eye. The recently developed full-field OCT technique, in which 2D en face tangential optical slices are directly recorded on a camera, was successfully applied for ex vivo eye imaging. However, in vivo human eye imaging has not been demonstrated yet. Here we present a novel non-contact full-field OCT system, which is capable of imaging in air and, therefore, shows potential for in vivo cornea imaging in patients. The first cellular-level resolution ex vivo images of cornea, obtained in a completely non-contact way, were demonstrated. We were able to scan through the entire cornea (400 µm) and resolve epithelium, Bowman's layer, stroma and endothelium. FFOCT images of the human cornea in vivo were obtained for the first time. The epithelium structures and stromal keratocyte cells were distinguishable. Both ex vivo and in vivo images were acquired with a large (1.26 mm x 1.26 mm) field of view. Cellular details in obtained images make this device a promising candidate for realization of high-resolution in vivo cornea imaging.

Photoacoustic simulation study of chirp excitation response from different size absorbers

NASA Astrophysics Data System (ADS)

Jnawali, K.; Chinni, B.; Dogra, V.; Rao, N.

2017-03-01

Photoacoustic (PA) imaging is a hybrid imaging modality that integrates the strength of optical and ultrasound imaging. Nanosecond (ns) pulsed lasers used in current PA imaging systems are expensive, bulky and they often waste energy. We propose and evaluate, through simulations, the use of a continuous wave (CW) laser whose amplitude is linear frequency modulated (chirp) for PA imaging. The chirp signal provides signal-to-side-lobe ratio (SSR) improvement potential and full control over PA signal frequencies excited in the sample. The PA signal spectrum is a function of absorber size and the time frequencies present in the chirp. A mismatch between the input chirp spectrum and the output PA signal spectrum can affect the compressed pulse that is recovered from cross-correlating the two. We have quantitatively characterized this effect. The k-wave Matlab tool box was used to simulate PA signals in three dimensions for absorbers ranging in size from 0.1 mm to 0.6 mm, in response to laser excitation amplitude that is linearly swept from 0.5 MHz to 4 MHz. This sweep frequency range was chosen based on the spectrum analysis of a PA signal generated from ex-vivo human prostate tissue samples. In comparison, the energy wastage by a ns laser pulse was also estimated. For the chirp methodology, the compressed pulse peak amplitude, pulse width and side lobe structure parameters were extracted for different size absorbers. While the SSR increased 6 fold with absorber size, the pulse width decreased by 25%.

Proteomic analysis of the gamma human papillomavirus type 197 E6 and E7 associated cellular proteins

PubMed Central

Grace, Miranda; Munger, Karl

2016-01-01

Gamma HPV197 was the most frequently identified HPV when human skin cancer specimens were analyzed by deep sequencing. To gain insight into the biological activities of HPV197, we investigated the cellular interactomes of HPV197 E6 and E7. HPV197 E6 protein interacts with a broad spectrum of cellular LXXLL domain proteins, including UBE3A and MAML1. HPV197 E6 also binds and inhibits the TP53 tumor suppressor and interacts with the CCR4-NOT ubiquitin ligase and deadenylation complex. Despite lacking a canonical retinoblastoma (RB1) tumor suppressor binding site, HPV197 E7 binds RB1 and activates E2F transcription. Hence, HPV197 E6 and E7 proteins interact with a similar set of cellular proteins as E6 and E7 proteins encoded by HPVs that have been linked to human carcinogenesis and/or have transforming activities in vitro. PMID:27771561

Imaging through Fog Using Polarization Imaging in the Visible/NIR/SWIR Spectrum

DTIC Science & Technology

2017-01-11

few haze effects as possible.  One post processing step on the image in order to complete image dehazing Figure 6: Basic architecture of the...Page 16 Figure 7: Basic architecture of post-processing techniques to recover an image dehazed from a raw image This first study was limited on the

Optical coherence microscopy for deep tissue imaging of the cerebral cortex with intrinsic contrast

PubMed Central

Srinivasan, Vivek J.; Radhakrishnan, Harsha; Jiang, James Y.; Barry, Scott; Cable, Alex E.

2012-01-01

In vivo optical microscopic imaging techniques have recently emerged as important tools for the study of neurobiological development and pathophysiology. In particular, two-photon microscopy has proved to be a robust and highly flexible method for in vivo imaging in highly scattering tissue. However, two-photon imaging typically requires extrinsic dyes or contrast agents, and imaging depths are limited to a few hundred microns. Here we demonstrate Optical Coherence Microscopy (OCM) for in vivo imaging of neuronal cell bodies and cortical myelination up to depths of ~1.3 mm in the rat neocortex. Imaging does not require the administration of exogenous dyes or contrast agents, and is achieved through intrinsic scattering contrast and image processing alone. Furthermore, using OCM we demonstrate in vivo, quantitative measurements of optical properties (index of refraction and attenuation coefficient) in the cortex, and correlate these properties with laminar cellular architecture determined from the images. Lastly, we show that OCM enables direct visualization of cellular changes during cell depolarization and may therefore provide novel optical markers of cell viability. PMID:22330462

Design of small confocal endo-microscopic probe working under multiwavelength environment

NASA Astrophysics Data System (ADS)

Kim, Young-Duk; Ahn, MyoungKi; Gweon, Dae-Gab

2010-02-01

Recently, optical imaging system is widely used in medical purpose. By using optical imaging system specific diseases can be easily diagnosed at early stage because optical imaging system has high resolution performance and various imaging method. These methods are used to get high resolution image of human body and can be used to verify whether the cell is infected by virus. Confocal microscope is one of the famous imaging systems which is used for in-vivo imaging. Because most of diseases are accompanied with cellular level changes, doctors can diagnosis at early stage by observing the cellular image of human organ. Current research is focused in the development of endo-microscope that has great advantage in accessibility to human body. In this research, I designed small probe that is connected to confocal microscope through optical fiber bundle and work as endo-microscope. And this small probe is mainly designed to correct chromatic aberration to use various laser sources for both fluorescence type and reflection type confocal images. By using two kinds of laser sources at the same time we demonstrated multi-modality confocal endo-microscope.

Internal Disequilibria and Phenotypic Diversification during Replication of Hepatitis C Virus in a Noncoevolving Cellular Environment

PubMed Central

Moreno, Elena; Gallego, Isabel; Gregori, Josep; Lucía-Sanz, Adriana; Soria, María Eugenia; Castro, Victoria; Beach, Nathan M.; Manrubia, Susanna; Quer, Josep; Esteban, Juan Ignacio; Rice, Charles M.; Gómez, Jordi; Gastaminza, Pablo

2017-01-01

ABSTRACT Viral quasispecies evolution upon long-term virus replication in a noncoevolving cellular environment raises relevant general issues, such as the attainment of population equilibrium, compliance with the molecular-clock hypothesis, or stability of the phenotypic profile. Here, we evaluate the adaptation, mutant spectrum dynamics, and phenotypic diversification of hepatitis C virus (HCV) in the course of 200 passages in human hepatoma cells in an experimental design that precluded coevolution of the cells with the virus. Adaptation to the cells was evidenced by increase in progeny production. The rate of accumulation of mutations in the genomic consensus sequence deviated slightly from linearity, and mutant spectrum analyses revealed a complex dynamic of mutational waves, which was sustained beyond passage 100. The virus underwent several phenotypic changes, some of which impacted the virus-host relationship, such as enhanced cell killing, a shift toward higher virion density, and increased shutoff of host cell protein synthesis. Fluctuations in progeny production and failure to reach population equilibrium at the genomic level suggest internal instabilities that anticipate an unpredictable HCV evolution in the complex liver environment. IMPORTANCE Long-term virus evolution in an unperturbed cellular environment can reveal features of virus evolution that cannot be explained by comparing natural viral isolates. In the present study, we investigate genetic and phenotypic changes that occur upon prolonged passage of hepatitis C virus (HCV) in human hepatoma cells in an experimental design in which host cell evolutionary change is prevented. Despite replication in a noncoevolving cellular environment, the virus exhibited internal population disequilibria that did not decline with increased adaptation to the host cells. The diversification of phenotypic traits suggests that disequilibria inherent to viral populations may provide a selective advantage to viruses that can be fully exploited in changing environments. PMID:28275194

Congenital coronary artery anomalies: a bridge from embryology to anatomy and pathophysiology--a position statement of the development, anatomy, and pathology ESC Working Group.

PubMed

Pérez-Pomares, José María; de la Pompa, José Luis; Franco, Diego; Henderson, Deborah; Ho, Siew Yen; Houyel, Lucile; Kelly, Robert G; Sedmera, David; Sheppard, Mary; Sperling, Silke; Thiene, Gaetano; van den Hoff, Maurice; Basso, Cristina

2016-02-01

Congenital coronary artery anomalies are of major significance in clinical cardiology and cardiac surgery due to their association with myocardial ischaemia and sudden death. Such anomalies are detectable by imaging modalities and, according to various definitions, their prevalence ranges from 0.21 to 5.79%. This consensus document from the Development, Anatomy and Pathology Working Group of the European Society of Cardiology aims to provide: (i) a definition of normality that refers to essential anatomical and embryological features of coronary vessels, based on the integrated analysis of studies of normal and abnormal coronary embryogenesis and pathophysiology; (ii) an animal model-based systematic survey of the molecular and cellular mechanisms that regulate coronary blood vessel development; (iii) an organization of the wide spectrum of coronary artery anomalies, according to a comprehensive anatomical and embryological classification scheme; (iv) current knowledge of the pathophysiological mechanisms underlying symptoms and signs of coronary artery anomalies, with diagnostic and therapeutic implications. This document identifies the mosaic-like embryonic development of the coronary vascular system, as coronary cell types differentiate from multiple cell sources through an intricate network of molecular signals and haemodynamic cues, as the necessary framework for understanding the complex spectrum of coronary artery anomalies observed in human patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

MO-DE-206-03: Quantifying Metabolism with Hyperpolarized MR

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

Bankson, J.

In this symposium jointly sponsored by the World Molecular Imaging Society (WMIS) and the AAPM, luminary speakers on imaging metabolism will discuss three impactful topics. The first presentation on Cellular Metabolism of FDG will be given by Guillem Pratx (Stanford). This presentation will detail new work on looking at how the most common molecular imaging agent, fluoro-deoxy-glucose is metabolized at a cellular level. This will be followed by a talk on an improved approach to whole-body PET imaging by Simon Cherry (UC Davis). Simon’s work on a new whole-body PET imaging system promises to have dramatic improvement in our abilitymore » to detect and characterize cancer using PET. Finally, Jim Bankson (MD Anderson) will discuss extremely sophisticated approaches to quantifying hyperpolarized-13-C pyruvate metabolism using MR imaging. This technology promises to compliment the exquisite sensitivity of PET with an ability to measure not just uptake, but tumor metabolism. Learning Objectives: Understand the metabolism of FDG at a cellular level. Appreciate the engineering related to a novel new high-sensitivity whole-body PET imaging system. Understand the process of hyperpolarization, how pyruvate relates to metabolism and how advanced modeling can be used to better quantify this data. G. Pratx, Funding: 5R01CA186275, 1R21CA193001, and Damon Runyon Cancer Foundation. S. Cherry, National Institutes of Health; University of California, Davis; Siemens Medical SolutionsJ. Bankson, GE Healthcare; NCI P30-CA016672; CPRIT PR140021-P5.« less

Differential conductance (dI/dV) imaging of a heterojunction-nanorod

NASA Astrophysics Data System (ADS)

Kundu, Biswajit; Bera, Abhijit; Pal, Amlan J.

2017-03-01

Through scanning tunneling spectroscopy, we envisage imaging a heterostructure, namely a junction formed in a single nanorod. While the differential conductance spectrum provides location of conduction and valence band edges, dI/dV images record energy levels of materials. Such dI/dV images at different voltages allowed us to view p- and n-sections of heterojunction nanorods and more importantly the depletion region in such a junction that has a type-II band alignment. Viewing of selective sections in a heterojunction occurred due to band-bending in the junction and is correlated to the density of states spectrum of the individual semiconductors. The dI/dV images recorded at different voltages could be used to generate a band diagram of a pn junction.

IMAGE-GUIDED EVALUATION AND MONITORING OF TREATMENT RESPONSE IN PATIENTS WITH DRY EYE DISEASE

PubMed Central

Hamrah, Pedram

2014-01-01

Dry eye disease (DED) is one of the most common ocular disorders worldwide. The pathophysiological mechanisms involved in the development of DED are not well understood and thus treating DED has been a significant challenge for ophthalmologists. Most of the currently available diagnostic tests demonstrate low correlation to patient symptoms and have low reproducibility. Recently, sophisticated in vivo imaging modalities have become available for patient care, namely, in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT). These emerging modalities are powerful and non-invasive, allowing real-time visualization of cellular and anatomical structures of the cornea and ocular surface. Here we discuss how, by providing both qualitative and quantitative assessment, these techniques can be used to demonstrate early subclinical disease, grade layer-by-layer severity, and allow monitoring of disease severity by cellular alterations. Imaging-guided stratification of patients may also be possible in conjunction with clinical examination methods. Visualization of subclinical changes and stratification of patients in vivo, allows objective image-guided evaluation of tailored treatment response based on cellular morphological alterations specific to each patient. This image-guided approach to DED may ultimately improve patient outcomes and allow studying the efficacy of novel therapies in clinical trials. PMID:24696045

Multispectral photoacoustic decomposition with localized regularization for detecting targeted contrast agent

NASA Astrophysics Data System (ADS)

Tavakoli, Behnoosh; Chen, Ying; Guo, Xiaoyu; Kang, Hyun Jae; Pomper, Martin; Boctor, Emad M.

2015-03-01

Targeted contrast agents can improve the sensitivity of imaging systems for cancer detection and monitoring the treatment. In order to accurately detect contrast agent concentration from photoacoustic images, we developed a decomposition algorithm to separate photoacoustic absorption spectrum into components from individual absorbers. In this study, we evaluated novel prostate-specific membrane antigen (PSMA) targeted agents for imaging prostate cancer. Three agents were synthesized through conjugating PSMA-targeting urea with optical dyes ICG, IRDye800CW and ATTO740 respectively. In our preliminary PA study, dyes were injected in a thin wall plastic tube embedded in water tank. The tube was illuminated with pulsed laser light using a tunable Q-switch ND-YAG laser. PA signal along with the B-mode ultrasound images were detected with a diagnostic ultrasound probe in orthogonal mode. PA spectrums of each dye at 0.5 to 20 μM concentrations were estimated using the maximum PA signal extracted from images which are obtained at illumination wavelengths of 700nm-850nm. Subsequently, we developed nonnegative linear least square optimization method along with localized regularization to solve the spectral unmixing. The algorithm was tested by imaging mixture of those dyes. The concentration of each dye was estimated with about 20% error on average from almost all mixtures albeit the small separation between dyes spectrums.

Comparison of Two Methods of Noise Power Spectrum Determinations of Medical Radiography Systems

NASA Astrophysics Data System (ADS)

Hassan, Wan Muhamad Saridan Wan; Ahmed Darwish, Zeki

2011-03-01

Noise in medical images is recognized as an important factor that determines the image quality. Image noise is characterized by noise power spectrum (NPS). We compared two methods of NPS determination namely the methods of Wagner and Dobbins on Lanex Regular TMG screen-film system and Hologic Lorad Selenia full field digital mammography system, with the aim of choosing the better method to use. The methods differ in terms of various parametric choices and algorithm implementations. These parameters include the low pass filtering, low frequency filtering, windowing, smoothing, aperture correction, overlapping of region of interest (ROI), length of fast Fourier transform, ROI size, method of ROI normalization, and slice selection of the NPS. Overall, the two methods agreed to the practical value of noise power spectrum between 10-3-10-6 mm2 over spatial frequency range 0-10 mm-1.

Relative radiometric calibration for multispectral remote sensing imagery

NASA Astrophysics Data System (ADS)

Ren, Hsuan

2006-10-01

Our environment has been changed continuously by nature causes or human activities. In order to identify what has been changed during certain time period, we need to spend enormous resources to collect all kinds of data and analyze them. With remote sensing images, change detection has become one efficient and inexpensive technique. It has wide applications including disaster management, agriculture analysis, environmental monitoring and military reconnaissance. To detect the changes between two remote sensing images collected at different time, radiometric calibration is one of the most important processes. Under the different weather and atmosphere conditions, even the same material might be resulting distinct radiance spectrum in two images. In this case, they will be misclassified as changes and false alarm rate will also increase. To achieve absolute calibration, i.e., to convert the radiance to reflectance spectrum, the information about the atmosphere condition or ground reference materials with known reflectance spectrum is needed but rarely available. In this paper, we present relative radiometric calibration methods which transform image pair into similar atmospheric effect instead of remove it in absolutely calibration, so that the information of atmosphere condition is not required. A SPOT image pair will be used for experiment to demonstrate the performance.

47 CFR 20.6 - CMRS spectrum aggregation limit.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the broadband PCS, cellular, or SMR services (including all parties under common control) regulated as... of the population of the PCS licensed service area for the counties contained therein, as determined... covers less than 10 percent of the population of a PCS service area if none of the base stations of the...

47 CFR 20.6 - CMRS spectrum aggregation limit.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the broadband PCS, cellular, or SMR services (including all parties under common control) regulated as... of the population of the PCS licensed service area for the counties contained therein, as determined... covers less than 10 percent of the population of a PCS service area if none of the base stations of the...

G protein-coupled receptor internalization assays in the high-content screening format.

PubMed

Haasen, Dorothea; Schnapp, Andreas; Valler, Martin J; Heilker, Ralf

2006-01-01

High-content screening (HCS), a combination of fluorescence microscopic imaging and automated image analysis, has become a frequently applied tool to study test compound effects in cellular disease-modeling systems. This chapter describes the measurement of G protein-coupled receptor (GPCR) internalization in the HCS format using a high-throughput, confocal cellular imaging device. GPCRs are the most successful group of therapeutic targets on the pharmaceutical market. Accordingly, the search for compounds that interfere with GPCR function in a specific and selective way is a major focus of the pharmaceutical industry today. This chapter describes methods for the ligand-induced internalization of GPCRs labeled previously with either a fluorophore-conjugated ligand or an antibody directed against an N-terminal tag of the GPCR. Both labeling techniques produce robust assay formats. Complementary to other functional GPCR drug discovery assays, internalization assays enable a pharmacological analysis of test compounds. We conclude that GPCR internalization assays represent a valuable medium/high-throughput screening format to determine the cellular activity of GPCR ligands.

Profile of new green fluorescent protein transgenic Jinhua pigs as an imaging source

NASA Astrophysics Data System (ADS)

Kawarasaki, Tatsuo; Uchiyama, Kazuhiko; Hirao, Atsushi; Azuma, Sadahiro; Otake, Masayoshi; Shibata, Masatoshi; Tsuchiya, Seiko; Enosawa, Shin; Takeuchi, Koichi; Konno, Kenjiro; Hakamata, Yoji; Yoshino, Hiroyuki; Wakai, Takuya; Ookawara, Shigeo; Tanaka, Hozumi; Kobayashi, Eiji; Murakami, Takashi

2009-09-01

Animal imaging sources have become an indispensable material for biological sciences. Specifically, gene-encoded biological probes serve as stable and high-performance tools to visualize cellular fate in living animals. We use a somatic cell cloning technique to create new green fluorescent protein (GFP)-expressing Jinhua pigs with a miniature body size, and characterized the expression profile in various tissues/organs and ex vivo culture conditions. The born GFP-transgenic pig demonstrate an organ/tissue-dependent expression pattern. Strong GFP expression is observed in the skeletal muscle, pancreas, heart, and kidney. Regarding cellular levels, bone-marrow-derived mesenchymal stromal cells, hepatocytes, and islet cells of the pancreas also show sufficient expression with the unique pattern. Moreover, the cloned pigs demonstrate normal growth and fertility, and the introduced GFP gene is stably transmitted to pigs in subsequent generations. The new GFP-expressing Jinhua pigs may be used as new cellular/tissue light resources for biological imaging in preclinical research fields such as tissue engineering, experimental regenerative medicine, and transplantation.

Adaptive optics optical coherence tomography at 120,000 depth scans/s for non-invasive cellular phenotyping of the living human retina

PubMed Central

Torti, Cristiano; Považay, Boris; Hofer, Bernd; Unterhuber, Angelika; Carroll, Joseph; Ahnelt, Peter Kurt; Drexler, Wolfgang

2012-01-01

This paper presents a successful combination of ultra-high speed (120,000 depth scans/s), ultra-high resolution optical coherence tomography with adaptive optics and an achromatizing lens for compensation of monochromatic and longitudinal chromatic ocular aberrations, respectively, allowing for non-invasive volumetric imaging in normal and pathologic human retinas at cellular resolution. The capability of this imaging system is demonstrated here through preliminary studies by probing cellular intraretinal structures that have not been accessible so far with in vivo, non-invasive, label-free imaging techniques, including pigment epithelial cells, micro-vasculature of the choriocapillaris, single nerve fibre bundles and collagenous plates of the lamina cribrosa in the optic nerve head. In addition, the volumetric extent of cone loss in two colour-blinds could be quantified for the first time. This novel technique provides opportunities to enhance the understanding of retinal pathogenesis and early diagnosis of retinal diseases. PMID:19997159

Telebation: next-generation telemedicine in remote airway management using current wireless technologies.

PubMed

Mosier, Jarrod; Joseph, Bellal; Sakles, John C

2013-02-01

Since the first remote intubation with telemedicine guidance, wireless technology has advanced to enable more portable methods of telemedicine involvement in remote airway management. Three voice over Internet protocol (VoIP) services were evaluated for quality of image transmitted, data lag, and audio quality with remotely observed and assisted intubations in an academic emergency department. The VoIP clients evaluated were Apple (Cupertino, CA) FaceTime(®), Skype™ (a division of Microsoft, Luxembourg City, Luxembourg), and Tango(®) (TangoMe, Palo Alto, CA). Each client was tested over a Wi-Fi network as well as cellular third generation (3G) (Skype and Tango). All three VoIP clients provided acceptable image and audio quality. There is a significant data lag in image transmission and quality when VoIP clients are used over cellular broadband (3G) compared with Wi-Fi. Portable remote telemedicine guidance is possible with newer technology devices such as a smartphone or tablet, as well as VoIP clients used over Wi-Fi or cellular broadband.

Molecular and cellular heterogeneity: the hallmark of glioblastoma.

PubMed

Aum, Diane J; Kim, David H; Beaumont, Thomas L; Leuthardt, Eric C; Dunn, Gavin P; Kim, Albert H

2014-12-01

There has been increasing awareness that glioblastoma, which may seem histopathologically similar across many tumors, actually represents a group of molecularly distinct tumors. Emerging evidence suggests that cells even within the same tumor exhibit wide-ranging molecular diversity. Parallel to the discoveries of molecular heterogeneity among tumors and their individual cells, intense investigation of the cellular biology of glioblastoma has revealed that not all cancer cells within a given tumor behave the same. The identification of a subpopulation of brain tumor cells termed "glioblastoma cancer stem cells" or "tumor-initiating cells" has implications for the management of glioblastoma. This focused review will therefore summarize emerging concepts on the molecular and cellular heterogeneity of glioblastoma and emphasize that we should begin to consider each individual glioblastoma to be an ensemble of molecularly distinct subclones that reflect a spectrum of dynamic cell states.

Chemo-enzymatic synthesis of isotopically labeled nicotinamide riboside.

PubMed

Tran, Ai; Yokose, Ryota; Cen, Yana

2018-05-15

As a cofactor for numerous reactions, NAD+ is found widely dispersed across many maps of cellular metabolism. This core redox role alone makes the biosynthesis of NAD+ of great interest. Recent studies have revealed new biological roles for NAD+ as a substrate for diverse enzymes that regulate a broad spectrum of key cellular tasks. These NAD+-consuming enzymes further highlight the importance of understanding NAD+ biosynthetic pathways. In this study, we developed a chemo-enzymatic synthesis of isotopically labeled NAD+ precursor, nicotinamide riboside (NR). The synthesis of NR isotopomers allowed us to unambiguously determine that NR is efficiently converted to NAD+ in the cellular environment independent of degradation to nicotinamide, and it is incorporated into NAD+ in its intact form. The versatile synthetic method along with the isotopically labeled NRs will provide powerful tools to further decipher the important yet complicated NAD+ metabolism.

Different Aberrant Mentalizing Networks in Males and Females with Autism Spectrum Disorders: Evidence from Resting-State Functional Magnetic Resonance Imaging

ERIC Educational Resources Information Center

Yang, Jie; Lee, Jonathan

2018-01-01

Previous studies have found that individuals with autism spectrum disorders show impairments in mentalizing processes and aberrant brain activity compared with typically developing participants. However, the findings are mainly from male participants and the aberrant effects in autism spectrum disorder females and sex differences are still…

Magnetic Resonance Microscopy (MRM) of Single Mammalian Myofibers and Myonuclei.

PubMed

Lee, Choong H; Bengtsson, Niclas; Chrzanowski, Stephen M; Flint, Jeremy J; Walter, Glenn A; Blackband, Stephen J

2017-01-03

Recently, the first magnetic resonance microscopy (MRM) images at the cellular level in isolated mammalian brain tissues were obtained using microsurface coils. These methods can elucidate the cellular origins of MR signals and describe how these signals change over the course of disease progression and therapy. In this work, we explore the capability of these microimaging techniques to visualize mouse muscle fibers and their nuclei. Isolated myofibers expressing lacZ were imaged with and without a stain for β-galactosidase activity (S-Gal + ferric ammonium citrate) that produces both optical and MR contrast. We found that MRM can be used to image single myofibers with 6-μm resolution. The ability to image single myofibers will serve as a valuable tool to study MR properties attributed to healthy and myopathic cells. The ability to image nuclei tagged with MR/Optical gene markers may also find wide use in cell lineage MRI studies.

Magnetic Resonance Microscopy (MRM) of Single Mammalian Myofibers and Myonuclei

PubMed Central

Lee, Choong H.; Bengtsson, Niclas; Chrzanowski, Stephen M.; Flint, Jeremy J.; Walter, Glenn A.; Blackband, Stephen J.

2017-01-01

Recently, the first magnetic resonance microscopy (MRM) images at the cellular level in isolated mammalian brain tissues were obtained using microsurface coils. These methods can elucidate the cellular origins of MR signals and describe how these signals change over the course of disease progression and therapy. In this work, we explore the capability of these microimaging techniques to visualize mouse muscle fibers and their nuclei. Isolated myofibers expressing lacZ were imaged with and without a stain for β-galactosidase activity (S-Gal + ferric ammonium citrate) that produces both optical and MR contrast. We found that MRM can be used to image single myofibers with 6-μm resolution. The ability to image single myofibers will serve as a valuable tool to study MR properties attributed to healthy and myopathic cells. The ability to image nuclei tagged with MR/Optical gene markers may also find wide use in cell lineage MRI studies. PMID:28045071

Imaging of oxygenation in 3D tissue models with multi-modal phosphorescent probes

NASA Astrophysics Data System (ADS)

Papkovsky, Dmitri B.; Dmitriev, Ruslan I.; Borisov, Sergei

2015-03-01

Cell-penetrating phosphorescence based probes allow real-time, high-resolution imaging of O2 concentration in respiring cells and 3D tissue models. We have developed a panel of such probes, small molecule and nanoparticle structures, which have different spectral characteristics, cell penetrating and tissue staining behavior. The probes are compatible with conventional live cell imaging platforms and can be used in different detection modalities, including ratiometric intensity and PLIM (Phosphorescence Lifetime IMaging) under one- or two-photon excitation. Analytical performance of these probes and utility of the O2 imaging method have been demonstrated with different types of samples: 2D cell cultures, multi-cellular spheroids from cancer cell lines and primary neurons, excised slices from mouse brain, colon and bladder tissue, and live animals. They are particularly useful for hypoxia research, ex-vivo studies of tissue physiology, cell metabolism, cancer, inflammation, and multiplexing with many conventional fluorophors and markers of cellular function.

Spirally-patterned pinhole arrays for long-term fluorescence cell imaging.

PubMed

Koo, Bon Ung; Kang, YooNa; Moon, SangJun; Lee, Won Gu

2015-11-07

Fluorescence cell imaging using a fluorescence microscope is an extensively used technique to examine the cell nucleus, internal structures, and other cellular molecules with fluorescence response time and intensity. However, it is difficult to perform high resolution cell imaging for a long period of time with this technique due to necrosis and apoptosis depending on the type and subcellular location of the damage caused by phototoxicity. A large number of studies have been performed to resolve this problem, but researchers have struggled to meet the challenge between cellular viability and image resolution. In this study, we employ a specially designed disc to reduce cell damage by controlling total fluorescence exposure time without deterioration of the image resolution. This approach has many advantages such as, the apparatus is simple, cost-effective, and easily integrated into the optical pathway through a conventional fluorescence microscope.

Self-assembled dual-modality contrast agents for non-invasive stem cell tracking via near-infrared fluorescence and magnetic resonance imaging.

PubMed

Liu, Hong; Tan, Yan; Xie, Lisi; Yang, Lei; Zhao, Jing; Bai, Jingxuan; Huang, Ping; Zhan, Wugen; Wan, Qian; Zou, Chao; Han, Yali; Wang, Zhiyong

2016-09-15

Stem cells hold great promise for treating various diseases. However, one of the main drawbacks of stem cell therapy is the lack of non-invasive image-tracking technologies. Although magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging have been employed to analyse cellular and subcellular events via the assistance of contrast agents, the sensitivity and temporal resolution of MRI and the spatial resolution of NIRF are still shortcomings. In this study, superparamagnetic iron oxide nanocrystals and IR-780 dyes were co-encapsulated in stearic acid-modified polyethylenimine to form a dual-modality contrast agent with nano-size and positive charge. These resulting agents efficiently labelled stem cells and did not influence the cellular viability and differentiation. Moreover, the labelled cells showed the advantages of dual-modality imaging in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

Performance of signal-to-noise ratio estimation for scanning electron microscope using autocorrelation Levinson-Durbin recursion model.

PubMed

Sim, K S; Lim, M S; Yeap, Z X

2016-07-01

A new technique to quantify signal-to-noise ratio (SNR) value of the scanning electron microscope (SEM) images is proposed. This technique is known as autocorrelation Levinson-Durbin recursion (ACLDR) model. To test the performance of this technique, the SEM image is corrupted with noise. The autocorrelation function of the original image and the noisy image are formed. The signal spectrum based on the autocorrelation function of image is formed. ACLDR is then used as an SNR estimator to quantify the signal spectrum of noisy image. The SNR values of the original image and the quantified image are calculated. The ACLDR is then compared with the three existing techniques, which are nearest neighbourhood, first-order linear interpolation and nearest neighbourhood combined with first-order linear interpolation. It is shown that ACLDR model is able to achieve higher accuracy in SNR estimation. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Eliminating Bias In Acousto-Optical Spectrum Analysis

NASA Technical Reports Server (NTRS)

Ansari, Homayoon; Lesh, James R.

1992-01-01

Scheme for digital processing of video signals in acousto-optical spectrum analyzer provides real-time correction for signal-dependent spectral bias. Spectrum analyzer described in "Two-Dimensional Acousto-Optical Spectrum Analyzer" (NPO-18092), related apparatus described in "Three-Dimensional Acousto-Optical Spectrum Analyzer" (NPO-18122). Essence of correction is to average over digitized outputs of pixels in each CCD row and to subtract this from the digitized output of each pixel in row. Signal processed electro-optically with reference-function signals to form two-dimensional spectral image in CCD camera.

In vivo imaging of cancer cell size and cellularity using temporal diffusion spectroscopy.

PubMed

Jiang, Xiaoyu; Li, Hua; Xie, Jingping; McKinley, Eliot T; Zhao, Ping; Gore, John C; Xu, Junzhong

2017-07-01

A temporal diffusion MRI spectroscopy based approach has been developed to quantify cancer cell size and density in vivo. A novel imaging microstructural parameters using limited spectrally edited diffusion (IMPULSED) method selects a specific limited diffusion spectral window for an accurate quantification of cell sizes ranging from 10 to 20 μm in common solid tumors. In practice, it is achieved by a combination of a single long diffusion time pulsed gradient spin echo (PGSE) and three low-frequency oscillating gradient spin echo (OGSE) acquisitions. To validate our approach, hematoxylin and eosin staining and immunostaining of cell membranes, in concert with whole slide imaging, were used to visualize nuclei and cell boundaries, and hence, enabled accurate estimates of cell size and cellularity. Based on a two compartment model (incorporating intra- and extracellular spaces), accurate estimates of cell sizes were obtained in vivo for three types of human colon cancers. The IMPULSED-derived apparent cellularities showed a stronger correlation (r = 0.81; P < 0.0001) with histology-derived cellularities than conventional ADCs (r = -0.69; P < 0.03). The IMPULSED approach samples a specific region of temporal diffusion spectra with enhanced sensitivity to length scales of 10-20 μm, and enables measurements of cell sizes and cellularities in solid tumors in vivo. Magn Reson Med 78:156-164, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Clinical multiphoton and CARS microscopy

NASA Astrophysics Data System (ADS)

Breunig, H. G.; Weinigel, M.; Darvin, M. E.; Lademann, J.; König, K.

2012-03-01

We report on clinical CARS imaging of human skin in vivo with the certified hybrid multiphoton tomograph CARSDermaInspect. The CARS-DermaInspect provides simultaneous imaging of non-fluorescent intradermal lipid and water as well as imaging of two-photon excited fluorescence from intrinsic molecules. Two different excitation schemes for CARS imaging have been realized: In the first setup, a combination of fs oscillator and optical parametric oscillator provided fs-CARS pump and Stokes pulses, respectively. In the second setup a fs oscillator was combined with a photonic crystal fiber which provided a broadband spectrum. A spectral range out of the broadband-spectrum was selected and used for CARS excitation in combination with the residual fs-oscillator output. In both setups, in addition to CARS, single-beam excitation was used for imaging of two-photon excited fluorescence and second harmonic generation signals. Both CARS-excitation systems were successfully used for imaging of lipids inside the skin in vivo.

Magnetic resonance imaging spectrum of perinatal hypoxic-ischemic brain injury

PubMed Central

Varghese, Binoj; Xavier, Rose; Manoj, V C; Aneesh, M K; Priya, P S; Kumar, Ashok; Sreenivasan, V K

2016-01-01

Perinatal hypoxic–ischemic brain injury results in neonatal hypoxic–ischemic encephalopathy and serious long-term neurodevelopmental sequelae. Magnetic resonance imaging (MRI) of the brain is an ideal and safe imaging modality for suspected hypoxic–ischemic injury. The pattern of injury depends on brain maturity at the time of insult, severity of hypotension, and duration of insult. Time of imaging after the insult influences the imaging findings. Mild to moderate hypoperfusion results in germinal matrix hemorrhages and periventricular leukomalacia in preterm neonates and parasagittal watershed territory infarcts in full-term neonates. Severe insult preferentially damages the deep gray matter in both term and preterm infants. However, associated frequent perirolandic injury is seen in term neonates. MRI is useful in establishing the clinical diagnosis, assessing the severity of injury, and thereby prognosticating the outcome. Familiarity with imaging spectrum and insight into factors affecting the injury will enlighten the radiologist to provide an appropriate diagnosis. PMID:27857456

Infrared Imaging Tools for Diagnostic Applications in Dermatology.

PubMed

Gurjarpadhye, Abhijit Achyut; Parekh, Mansi Bharat; Dubnika, Arita; Rajadas, Jayakumar; Inayathullah, Mohammed

Infrared (IR) imaging is a collection of non-invasive imaging techniques that utilize the IR domain of the electromagnetic spectrum for tissue assessment. A subset of these techniques construct images using back-reflected light, while other techniques rely on detection of IR radiation emitted by the tissue as a result of its temperature. Modern IR detectors sense thermal emissions and produce a heat map of surface temperature distribution in tissues. Thus, the IR spectrum offers a variety of imaging applications particularly useful in clinical diagnostic area, ranging from high-resolution, depth-resolved visualization of tissue to temperature variation assessment. These techniques have been helpful in the diagnosis of many medical conditions including skin/breast cancer, arthritis, allergy, burns, and others. In this review, we discuss current roles of IR-imaging techniques for diagnostic applications in dermatology with an emphasis on skin cancer, allergies, blisters, burns and wounds.

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

Imaging of single cells and tissue using MeV ions

NASA Astrophysics Data System (ADS)

Watt, F.; Bettiol, A. A.; van Kan, J. A.; Ynsa, M. D.; Minqin, Ren; Rajendran, R.; Huifang, Cui; Fwu-Shen, Sheu; Jenner, A. M.

2009-06-01

With the attainment of sub-100 nm high energy (MeV) ion beams, comes the opportunity to image cells and tissue at nano-dimensions. The advantage of MeV ion imaging is that the ions will penetrate whole cells, or relatively thick tissue sections, without any significant loss of resolution. In this paper, we demonstrate that whole cells (cultured N2A neuroblastoma cells ATCC) and tissue sections (rabbit pancreas tissue) can be imaged at sub-100 nm resolutions using scanning transmission ion microscopy (STIM), and that sub-cellular structural details can be identified. In addition to STIM imaging we have also demonstrated for the first time, that sub-cellular proton induced fluorescence imaging (on cultured N2A neuroblastoma cells ATCC) can also be carried out at resolutions of 200 nm, compared with 300-400 nm resolutions achieved by conventional optical fluorescence imaging. The combination of both techniques offers a potentially powerful tool in the quest for elucidating cell function, particularly when it should be possible in the near future to image down to sub-50 nm.

Nanoscale live cell optical imaging of the dynamics of intracellular microvesicles in neural cells.

PubMed

Lee, Sohee; Heo, Chaejeong; Suh, Minah; Lee, Young Hee

2013-11-01

Recent advances in biotechnology and imaging technology have provided great opportunities to investigate cellular dynamics. Conventional imaging methods such as transmission electron microscopy, scanning electron microscopy, and atomic force microscopy are powerful techniques for cellular imaging, even at the nanoscale level. However, these techniques have limitations applications in live cell imaging because of the experimental preparation required, namely cell fixation, and the innately small field of view. In this study, we developed a nanoscale optical imaging (NOI) system that combines a conventional optical microscope with a high resolution dark-field condenser (Cytoviva, Inc.) and halogen illuminator. The NOI system's maximum resolution for live cell imaging is around 100 nm. We utilized NOI to investigate the dynamics of intracellular microvesicles of neural cells without immunocytological analysis. In particular, we studied direct, active random, and moderate random dynamic motions of intracellular microvesicles and visualized lysosomal vesicle changes after treatment of cells with a lysosomal inhibitor (NH4Cl). Our results indicate that the NOI system is a feasible, high-resolution optical imaging system for live small organelles that does not require complicated optics or immunocytological staining processes.

Bio-metals imaging and speciation in cells using proton and synchrotron radiation X-ray microspectroscopy

PubMed Central

Ortega, Richard; Devès, Guillaume; Carmona, Asunción

2009-01-01

The direct detection of biologically relevant metals in single cells and of their speciation is a challenging task that requires sophisticated analytical developments. The aim of this article is to present the recent achievements in the field of cellular chemical element imaging, and direct speciation analysis, using proton and synchrotron radiation X-ray micro- and nano-analysis. The recent improvements in focusing optics for MeV-accelerated particles and keV X-rays allow application to chemical element analysis in subcellular compartments. The imaging and quantification of trace elements in single cells can be obtained using particle-induced X-ray emission (PIXE). The combination of PIXE with backscattering spectrometry and scanning transmission ion microscopy provides a high accuracy in elemental quantification of cellular organelles. On the other hand, synchrotron radiation X-ray fluorescence provides chemical element imaging with less than 100 nm spatial resolution. Moreover, synchrotron radiation offers the unique capability of spatially resolved chemical speciation using micro-X-ray absorption spectroscopy. The potential of these methods in biomedical investigations will be illustrated with examples of application in the fields of cellular toxicology, and pharmacology, bio-metals and metal-based nano-particles. PMID:19605403

Clinical confocal microlaparoscope for real-time in vivo optical biopsies

NASA Astrophysics Data System (ADS)

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

2009-07-01

Successful treatment of cancer is highly dependent on the stage at which it is diagnosed. Early diagnosis, when the disease is still localized at its origin, results in very high cure rates-even for cancers that typically have poor prognosis. Biopsies are often used for diagnosis of disease. However, because biopsies are destructive, only a limited number can be taken. This leads to reduced sensitivity for detection due to sampling error. A real-time fluorescence confocal microlaparoscope has been developed that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device includes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. It has a 3-μm lateral resolution and a 25-μm axial resolution. Initial in vivo clinical testing using the device to image human ovaries has been done in 21 patients. Results indicate that the device can successfully image organs in vivo without complications. Results with excised tissue demonstrate that the instrument can resolve sufficient cellular detail to visualize the cellular changes associated with the onset of cancer.

Multiphoton fluorescence imaging of NADH to quantify metabolic changes in epileptic tissue in vitro

NASA Astrophysics Data System (ADS)

Chia, Thomas H.; Zinter, Joseph; Spencer, Dennis D.; Williamson, Anne; Levene, Michael J.

2007-02-01

A powerful advantage of multiphoton microscopy is its ability to image endogenous fluorophores such as the ubiquitous coenzyme NADH in discrete cellular populations. NADH is integral in both oxidative and non-oxidative cellular metabolism. NADH loses fluorescence upon oxidation to NAD +; thus changes in NADH fluorescence can be used to monitor metabolism. Recent studies have suggested that hypo metabolic astrocytes play an important role in cases of temporal lobe epilepsy (TLE). Current theories suggest this may be due to defective and/or a reduced number of mitochondria or dysfunction of the neuronal-astrocytic metabolic coupling. Measuring NADH fluorescence changes following chemical stimulation enables the quantification of the cellular distribution of metabolic anomalies in epileptic brain tissue compared to healthy tissue. We present what we believe to be the first multiphoton microscopy images of NADH from the human brain. We also present images of NADH fluorescence from the hippocampus of the kainate-treated rat TLE model. In some experiments, human and rat astrocytes were selectively labeled with the fluorescent dye sulforhodamine 101 (SR101). Our results demonstrate that multiphoton microscopy is a powerful tool for assaying the metabolic pathologies associated with temporal lobe epilepsy in humans and in rodent models.

A Graphene-enhanced imaging of microRNA with enzyme-free signal amplification of catalyzed hairpin assembly in living cells.

PubMed

Liu, Haiyun; Tian, Tian; Ji, Dandan; Ren, Na; Ge, Shenguang; Yan, Mei; Yu, Jinghua

2016-11-15

In situ imaging of miRNA in living cells could help us to monitor the miRNA expression in real time and obtain accurate information for studying miRNA related bioprocesses and disease. Given the low-level expression of miRNA, amplification strategies for intracellular miRNA are imperative. Here, we propose an amplification strategy with a non-destructive enzyme-free manner in living cells using catalyzed hairpin assembly (CHA) based on graphene oxide (GO) for cellular miRNA imaging. The enzyme-free CHA exhibits stringent recognition and excellent signal amplification of miRNA in the living cells. GO is a good candidate as a fluorescence quencher and cellular carrier. Taking the advantages of the CHA and GO, we can monitor the miRNA at low level in living cells with a simple, sensitive and real-time manner. Finally, imaging of miRNAs in the different expression cells is realized. The novel method could supply an effective tool to visualize intracellular low-level miRNAs and help us to further understand the role of miRNAs in cellular processes. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging approaches for the study of cell based cardiac therapies

PubMed Central

Lau, Joe F.; Anderson, Stasia A.; Adler, Eric; Frank, Joseph A.

2009-01-01

Despite promising preclinical data, the treatment of cardiovascular diseases using embryonic, bone-marrow-derived, and skeletal myoblast stem cells has not yet come to fruition within mainstream clinical practice. Major obstacles in cardiac stem cell investigations include the ability to monitor cell engraftment and survival following implantation within the myocardium. Several cellular imaging modalities, including reporter gene and MRI-based tracking approaches, have emerged that provide the means to identify, localize and monitor stem cells longitudinally in vivo following implantation. This Review will examine the various cardiac cellular tracking modalities, including the combinatorial use of several probes in multimodality imaging, with a focus on data from the last five years. PMID:20027188

Automated microscopy for high-content RNAi screening

PubMed Central

2010-01-01

Fluorescence microscopy is one of the most powerful tools to investigate complex cellular processes such as cell division, cell motility, or intracellular trafficking. The availability of RNA interference (RNAi) technology and automated microscopy has opened the possibility to perform cellular imaging in functional genomics and other large-scale applications. Although imaging often dramatically increases the content of a screening assay, it poses new challenges to achieve accurate quantitative annotation and therefore needs to be carefully adjusted to the specific needs of individual screening applications. In this review, we discuss principles of assay design, large-scale RNAi, microscope automation, and computational data analysis. We highlight strategies for imaging-based RNAi screening adapted to different library and assay designs. PMID:20176920

A novel chaotic based image encryption using a hybrid model of deoxyribonucleic acid and cellular automata

NASA Astrophysics Data System (ADS)

Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi

2015-08-01

Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.

Cellular Angiofibroma of the Nasopharynx.

PubMed

Erdur, Zülküf Burak; Yener, Haydar Murat; Yilmaz, Mehmet; Karaaltin, Ayşegül Batioğlu; Inan, Hakki Caner; Alaskarov, Elvin; Gozen, Emine Deniz

2017-11-01

Angiofibroma is a common tumor of the nasopharynx region but cellular type is extremely rare in head and neck. A 13-year-old boy presented with frequent epistaxis and nasal obstruction persisting for 6 months. According to the clinical symptoms and imaging studies juvenile angiofibroma was suspected. Following angiographic embolization total excision of the lesion by midfacial degloving approach was performed. Histological examination revealed that the tumor consisted of staghorn blood vessels and irregular fibrous stroma. Stellate fibroblasts with small pyknotic to large vesicular nuclei were seen in a highly cellular stroma. These findings identified cellular angiofibroma mimicking juvenile angiofibroma. This article is about a very rare patient of cellular angiofibroma of nasopharynx.

Characterizing the behavior of scattered radiation in multi-energy x-ray imaging

NASA Astrophysics Data System (ADS)

Sossin, Artur; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.

2017-04-01

Scattered radiation results in various undesirable effects in medical diagnostics, non-destructive testing (NDT) and security x-ray imaging. Despite numerous studies characterizing this phenomenon and its effects, the knowledge of its behavior in the energy domain remains limited. The present study aims at summarizing some key insights on scattered radiation originating from the inspected object. In addition, various simulations and experiments with limited collimation on both simplified and realistic phantoms were conducted in order to study scatter behavior in multi-energy x-ray imaging. Results showed that the spectrum shape of the scatter component can be considered preserved in the first approximation across the image plane for various acquisition geometries and phantoms. The variations exhibited by the scatter spectrum were below 10% for most examined cases. Furthermore, the corresponding spectrum shape proved to be also relatively invariant for different experimental angular projections of one of the examined phantoms. The observed property of scattered radiation can potentially lead to the decoupling of spatial and energy scatter components, which can in turn enable speed ups in scatter simulations and reduce the complexity of scatter correction.

Asymmetric multiple information cryptosystem based on chaotic spiral phase mask and random spectrum decomposition

NASA Astrophysics Data System (ADS)

Rafiq Abuturab, Muhammad

2018-01-01

A new asymmetric multiple information cryptosystem based on chaotic spiral phase mask (CSPM) and random spectrum decomposition is put forwarded. In the proposed system, each channel of secret color image is first modulated with a CSPM and then gyrator transformed. The gyrator spectrum is randomly divided into two complex-valued masks. The same procedure is applied to multiple secret images to get their corresponding first and second complex-valued masks. Finally, first and second masks of each channel are independently added to produce first and second complex ciphertexts, respectively. The main feature of the proposed method is the different secret images encrypted by different CSPMs using different parameters as the sensitive decryption/private keys which are completely unknown to unauthorized users. Consequently, the proposed system would be resistant to potential attacks. Moreover, the CSPMs are easier to position in the decoding process owing to their own centering mark on axis focal ring. The retrieved secret images are free from cross-talk noise effects. The decryption process can be implemented by optical experiment. Numerical simulation results demonstrate the viability and security of the proposed method.

From regular text to artistic writing and artworks: Fourier statistics of images with low and high aesthetic appeal

PubMed Central

Melmer, Tamara; Amirshahi, Seyed A.; Koch, Michael; Denzler, Joachim; Redies, Christoph

2013-01-01

The spatial characteristics of letters and their influence on readability and letter identification have been intensely studied during the last decades. There have been few studies, however, on statistical image properties that reflect more global aspects of text, for example properties that may relate to its aesthetic appeal. It has been shown that natural scenes and a large variety of visual artworks possess a scale-invariant Fourier power spectrum that falls off linearly with increasing frequency in log-log plots. We asked whether images of text share this property. As expected, the Fourier spectrum of images of regular typed or handwritten text is highly anisotropic, i.e., the spectral image properties in vertical, horizontal, and oblique orientations differ. Moreover, the spatial frequency spectra of text images are not scale-invariant in any direction. The decline is shallower in the low-frequency part of the spectrum for text than for aesthetic artworks, whereas, in the high-frequency part, it is steeper. These results indicate that, in general, images of regular text contain less global structure (low spatial frequencies) relative to fine detail (high spatial frequencies) than images of aesthetics artworks. Moreover, we studied images of text with artistic claim (ornate print and calligraphy) and ornamental art. For some measures, these images assume average values intermediate between regular text and aesthetic artworks. Finally, to answer the question of whether the statistical properties measured by us are universal amongst humans or are subject to intercultural differences, we compared images from three different cultural backgrounds (Western, East Asian, and Arabic). Results for different categories (regular text, aesthetic writing, ornamental art, and fine art) were similar across cultures. PMID:23554592

Metal plasmon-coupled fluorescence imaging and label free coenzyme detection in cells

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

Zhang, Jian, E-mail: jian@cfs.bioment.umaryland.edu; Fu, Yi; Li, Ge

2012-08-31

Highlights: Black-Right-Pointing-Pointer Metal nanoparticle for fluorescence cell imaging. Black-Right-Pointing-Pointer Non-invasive emission detection of coenzyme in cell on time-resolved confocal microscope. Black-Right-Pointing-Pointer Near-field interaction of flavin adenine dinucleotide with silver substrate. Black-Right-Pointing-Pointer Isolation of emissions by coenzymes from cellular autofluorescence on fluorescence cell imaging. -- Abstract: Flavin adenine dinucleotide (FAD) is a key metabolite in cellular energy conversion. Flavin can also bind with some enzymes in the metabolic pathway and the binding sites may be changed due to the disease progression. Thus, there is interest on studying its expression level, distribution, and redox state within the cells. FAD is naturally fluorescent,more » but it has a modest extinction coefficient and quantum yield. Hence the intrinsic emission from FAD is generally too weak to be isolated distinctly from the cellular backgrounds in fluorescence cell imaging. In this article, the metal nanostructures on the glass coverslips were used as substrates to measure FAD in cells. Particulate silver films were fabricated with an optical resonance near the absorption and the emission wavelengths of FAD which can lead to efficient coupling interactions. As a result, the emission intensity and quantum yield by FAD were greatly increased and the lifetime was dramatically shortened resulting in less interference from the longer lived cellular background. This feature may overcome the technical limits that hinder the direct observation of intrinsically fluorescent coenzymes in the cells by fluorescence microscopy. Fluorescence cell imaging on the metallic particle substrates may provide a non-invasive strategy for collecting the information of coenzymes in cells.« less

Time-Lapse Video Microscopy for Assessment of EYFP-Parkin Aggregation as a Marker for Cellular Mitophagy

PubMed Central

Di Sante, Gabriele; Casimiro, Mathew C.; Pestell, Timothy G.; Pestell, Richard G.

2016-01-01

Time-lapse video microscopy can be defined as the real time imaging of living cells. This technique relies on the collection of images at different time points. Time intervals can be set through a computer interface that controls the microscope-integrated camera. This kind of microscopy requires both the ability to acquire very rapid events and the signal generated by the observed cellular structure during these events. After the images have been collected, a movie of the entire experiment is assembled to show the dynamic of the molecular events of interest. Time-lapse video microscopy has a broad range of applications in the biomedical research field and is a powerful and unique tool for following the dynamics of the cellular events in real time. Through this technique, we can assess cellular events such as migration, division, signal transduction, growth, and death. Moreover, using fluorescent molecular probes we are able to mark specific molecules, such as DNA, RNA or proteins and follow them through their molecular pathways and functions. Time-lapse video microscopy has multiple advantages, the major one being the ability to collect data at the single-cell level, that make it a unique technology for investigation in the field of cell biology. However, time-lapse video microscopy has limitations that can interfere with the acquisition of high quality images. Images can be compromised by both external factors; temperature fluctuations, vibrations, humidity and internal factors; pH, cell motility. Herein, we describe a protocol for the dynamic acquisition of a specific protein, Parkin, fused with the enhanced yellow fluorescent protein (EYFP) in order to track the selective removal of damaged mitochondria, using a time-lapse video microscopy approach. PMID:27168174

Growth and setting of gas bubbles in a viscoelastic matrix imaged by X-ray microtomography: the evolution of cellular structures in fermenting wheat flour dough.

PubMed

Turbin-Orger, A; Babin, P; Boller, E; Chaunier, L; Chiron, H; Della Valle, G; Dendievel, R; Réguerre, A L; Salvo, L

2015-05-07

X-ray tomography is a relevant technique for the dynamic follow-up of gas bubbles in an opaque viscoelastic matrix, especially using image analysis. It has been applied here to pieces of fermenting wheat flour dough of various compositions, at two different voxel sizes (15 and 5 μm). The resulting evolution of the main cellular features shows that the creation of cellular structures follows two regimes that are defined by a characteristic time of connectivity, tc [30 and 80 min]: first (t ≤ tc), bubbles grow freely and then (t ≥ tc) they become connected since the percolation of the gas phase is limited by liquid films. During the first regime, bubbles can be tracked and the local strain rate can be measured. Its values (10(-4)-5 × 10(-4) s(-1)) are in agreement with those computed from dough viscosity and internal gas pressure, both of which depend on the composition. For higher porosity, P = 0.64 in our case, and thus occurring in the second regime, different cellular structures are obtained and XRT images show deformed gas cells that display complex shapes. The comparison of these images with confocal laser scanning microscopy images suggests the presence of liquid films that separate these cells. The dough can therefore be seen as a three-phase medium: viscoelastic matrix/gas cell/liquid phase. The contributions of the different levels of matter organization can be integrated by defining a capillary number (C = 0.1-1) that makes it possible to predict the macroscopic dough behavior.

Time-Lapse Video Microscopy for Assessment of EYFP-Parkin Aggregation as a Marker for Cellular Mitophagy.

PubMed

Di Sante, Gabriele; Casimiro, Mathew C; Pestell, Timothy G; Pestell, Richard G

2016-05-04

Time-lapse video microscopy can be defined as the real time imaging of living cells. This technique relies on the collection of images at different time points. Time intervals can be set through a computer interface that controls the microscope-integrated camera. This kind of microscopy requires both the ability to acquire very rapid events and the signal generated by the observed cellular structure during these events. After the images have been collected, a movie of the entire experiment is assembled to show the dynamic of the molecular events of interest. Time-lapse video microscopy has a broad range of applications in the biomedical research field and is a powerful and unique tool for following the dynamics of the cellular events in real time. Through this technique, we can assess cellular events such as migration, division, signal transduction, growth, and death. Moreover, using fluorescent molecular probes we are able to mark specific molecules, such as DNA, RNA or proteins and follow them through their molecular pathways and functions. Time-lapse video microscopy has multiple advantages, the major one being the ability to collect data at the single-cell level, that make it a unique technology for investigation in the field of cell biology. However, time-lapse video microscopy has limitations that can interfere with the acquisition of high quality images. Images can be compromised by both external factors; temperature fluctuations, vibrations, humidity and internal factors; pH, cell motility. Herein, we describe a protocol for the dynamic acquisition of a specific protein, Parkin, fused with the enhanced yellow fluorescent protein (EYFP) in order to track the selective removal of damaged mitochondria, using a time-lapse video microscopy approach.

Fiber-optic two-photon optogenetic stimulation.

PubMed

Dhakal, K; Gu, L; Black, B; Mohanty, S K

2013-06-01

Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells.

[Brain imaging in autism spectrum disorders. A review].

PubMed

Dziobek, I; Köhne, S

2011-05-01

In the past two decades, an increasing number of functional and structural brain imaging studies has provided insights into the neurobiological basis of autism spectrum disorders (ASD). This article summarizes pertinent functional brain imaging studies addressing the neuronal underpinnings of ASD symptomatology (impairments in social interaction and communication, repetitive and restrictive behavior) and associated neuropsychological deficits (theory of mind, executive functions, central coherence), complemented by relevant structural imaging findings. The results of these studies show that although cognitive functions in ASD are generally mediated by the same brain regions as in typically developed individuals, the degree and especially the patterns of brain activation often differ. Therefore, a hypothesis of aberrant network connectivity has increasingly been favored over one of focal brain dysfunction.

Autism spectrum disorder: does neuroimaging support the DSM-5 proposal for a symptom dyad? A systematic review of functional magnetic resonance imaging and diffusion tensor imaging studies.

PubMed

Pina-Camacho, Laura; Villero, Sonia; Fraguas, David; Boada, Leticia; Janssen, Joost; Navas-Sánchez, Francisco J; Mayoral, Maria; Llorente, Cloe; Arango, Celso; Parellada, Mara

2012-07-01

A systematic review of 208 studies comprising functional magnetic resonance imaging and diffusion tensor imaging data in patients with 'autism spectrum disorder' (ASD) was conducted, in order to determine whether these data support the forthcoming DSM-5 proposal of a social communication and behavioral symptom dyad. Studies consistently reported abnormal function and structure of fronto-temporal and limbic networks with social and pragmatic language deficits, of temporo-parieto-occipital networks with syntactic-semantic language deficits, and of fronto-striato-cerebellar networks with repetitive behaviors and restricted interests in ASD patients. Therefore, this review partially supports the DSM-5 proposal for the ASD dyad.

Predictive searching algorithm for Fourier ptychography

NASA Astrophysics Data System (ADS)

Li, Shunkai; Wang, Yifan; Wu, Weichen; Liang, Yanmei

2017-12-01

By capturing a set of low-resolution images under different illumination angles and stitching them together in the Fourier domain, Fourier ptychography (FP) is capable of providing high-resolution image with large field of view. Despite its validity, long acquisition time limits its real-time application. We proposed an incomplete sampling scheme in this paper, termed the predictive searching algorithm to shorten the acquisition and recovery time. Informative sub-regions of the sample’s spectrum are searched and the corresponding images of the most informative directions are captured for spectrum expansion. Its effectiveness is validated by both simulated and experimental results, whose data requirement is reduced by ˜64% to ˜90% without sacrificing image reconstruction quality compared with the conventional FP method.

Supplemental blue LED lighting array to improve the signal quality in hyperspectral imaging of plants.

PubMed

Mahlein, Anne-Katrin; Hammersley, Simon; Oerke, Erich-Christian; Dehne, Heinz-Wilhelm; Goldbach, Heiner; Grieve, Bruce

2015-06-01

Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400-500 nm) of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs) with an emission peak at 470 nm.

Hyperspectral Image Analysis for Skin Tumor Detection

NASA Astrophysics Data System (ADS)

Kong, Seong G.; Park, Lae-Jeong

This chapter presents hyperspectral imaging of fluorescence for nonin-vasive detection of tumorous tissue on mouse skin. Hyperspectral imaging sensors collect two-dimensional (2D) image data of an object in a number of narrow, adjacent spectral bands. This high-resolution measurement of spectral information reveals a continuous emission spectrum for each image pixel useful for skin tumor detection. The hyperspectral image data used in this study are fluorescence intensities of a mouse sample consisting of 21 spectral bands in the visible spectrum of wavelengths ranging from 440 to 640 nm. Fluorescence signals are measured using a laser excitation source with the center wavelength of 337 nm. An acousto-optic tunable filter is used to capture individual spectral band images at a 10-nm resolution. All spectral band images are spatially registered with the reference band image at 490 nm to obtain exact pixel correspondences by compensating the offsets caused during the image capture procedure. The support vector machines with polynomial kernel functions provide decision boundaries with a maximum separation margin to classify malignant tumor and normal tissue from the observed fluorescence spectral signatures for skin tumor detection.

Nanoparticle-facilitated functional and molecular imaging for the early detection of cancer

PubMed Central

Sivasubramanian, Maharajan; Hsia, Yu; Lo, Leu-Wei

2014-01-01

Cancer detection in its early stages is imperative for effective cancer treatment and patient survival. In recent years, biomedical imaging techniques, such as magnetic resonance imaging, computed tomography and ultrasound have been greatly developed and have served pivotal roles in clinical cancer management. Molecular imaging (MI) is a non-invasive imaging technique that monitors biological processes at the cellular and sub-cellular levels. To achieve these goals, MI uses targeted imaging agents that can bind targets of interest with high specificity and report on associated abnormalities, a task that cannot be performed by conventional imaging techniques. In this respect, MI holds great promise as a potential therapeutic tool for the early diagnosis of cancer. Nevertheless, the clinical applications of targeted imaging agents are limited due to their inability to overcome biological barriers inside the body. The use of nanoparticles has made it possible to overcome these limitations. Hence, nanoparticles have been the subject of a great deal of recent studies. Therefore, developing nanoparticle-based imaging agents that can target tumors via active or passive targeting mechanisms is desirable. This review focuses on the applications of various functionalized nanoparticle-based imaging agents used in MI for the early detection of cancer. PMID:25988156

Super-resolution imaging of multiple cells by optimized flat-field epi-illumination

NASA Astrophysics Data System (ADS)

Douglass, Kyle M.; Sieben, Christian; Archetti, Anna; Lambert, Ambroise; Manley, Suliana

2016-11-01

Biological processes are inherently multi-scale, and supramolecular complexes at the nanoscale determine changes at the cellular scale and beyond. Single-molecule localization microscopy (SMLM) techniques have been established as important tools for studying cellular features with resolutions of the order of around 10 nm. However, in their current form these modalities are limited by a highly constrained field of view (FOV) and field-dependent image resolution. Here, we develop a low-cost microlens array (MLA)-based epi-illumination system—flat illumination for field-independent imaging (FIFI)—that can efficiently and homogeneously perform simultaneous imaging of multiple cells with nanoscale resolution. The optical principle of FIFI, which is an extension of the Köhler integrator, is further elucidated and modelled with a new, free simulation package. We demonstrate FIFI's capabilities by imaging multiple COS-7 and bacteria cells in 100 × 100 μm2 SMLM images—more than quadrupling the size of a typical FOV and producing near-gigapixel-sized images of uniformly high quality.

X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging

NASA Astrophysics Data System (ADS)

Vågberg, William; Larsson, Daniel H.; Li, Mei; Arner, Anders; Hertz, Hans M.

2015-11-01

Imaging of muscular structure with cellular or subcellular detail in whole-body animal models is of key importance for understanding muscular disease and assessing interventions. Classical histological methods for high-resolution imaging methods require excision, fixation and staining. Here we show that the three-dimensional muscular structure of unstained whole zebrafish can be imaged with sub-5 μm detail with X-ray phase-contrast tomography. Our method relies on a laboratory propagation-based phase-contrast system tailored for detection of low-contrast 4-6 μm subcellular myofibrils. The method is demonstrated on 20 days post fertilization zebrafish larvae and comparative histology confirms that we resolve individual myofibrils in the whole-body animal. X-ray imaging of healthy zebrafish show the expected structured muscle pattern while specimen with a dystrophin deficiency (sapje) displays an unstructured pattern, typical of Duchenne muscular dystrophy. The method opens up for whole-body imaging with sub-cellular detail also of other types of soft tissue and in different animal models.

Correlative cryogenic tomography of cells using light and soft x-rays

PubMed Central

Smith, Elizabeth A.; Cinquin, Bertrand P.; Do, Myan; McDermott, Gerry; Le Gros, Mark A.; Larabell, Carolyn A.

2013-01-01

Correlated imaging is the process of imaging a specimen with two complementary modalities, and then combining the two data sets to create a highly informative, composite view. A recent implementation of this concept has been the combination of soft x-ray tomography (SXT) with fluorescence cryogenic microscopy (FCM). SXT-FCM is used to visualize cells that are held in a near-native, cryo-preserved state. The resultant images are, therefore, highly representative of both the cellular architecture and molecular organization in vivo. SXT quantitatively visualizes the cell and sub-cellular structures; FCM images the spatial distribution of fluorescently labeled molecules. Here, we review the characteristics of SXT-FCM, and briefly discuss how this method compares with existing correlative imaging techniques. We also describe how the incorporation of a cryo-rotation stage into a cryogenic fluorescence microscope allows acquisition of fluorescence cryogenic tomography (FCT) data. FCT is optimally suited to correlation with SXT, since both techniques image the specimen in 3-D, potentially with similar, isotropic spatial resolution. PMID:24355261

Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the X-ray photon energy spectrum.

PubMed

Benz, Mark G; Benz, Matthew W; Birnbaum, Steven B; Chason, Eric; Sheldon, Brian W; McGuire, Dale

2014-08-01

This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the X-ray photon energy spectrum. This is done by placing a hafnium filter between the X-ray generator and a pediatric abdominal phantom. A CT system manufactured in 1999 that was in the process of being remanufactured was used as the platform for this study. This system had the advantage of easy access to the X-ray generator for modifications to change the X-ray photon energy spectrum; it also had the disadvantage of not employing the latest post-imaging noise reduction iterative reconstruction technology. Because we observed improvements after changing the X-ray photon energy spectrum, we recommend a future study combining this change with an optimized iterative reconstruction noise reduction technique.

A study on the cytotoxicity of carbon-based materials

DOE PAGES

Saha, Dipendu; Heldt, Caryn L.; Gencoglu, Maria F.; ...

2016-05-25

With an aim to understand the origin and key contributing factors towards carboninduced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, x-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROX) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicitymore » in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under study. None of the carbons induced oxidative stress to the cells as indicated by the ROX generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell.« less

Dual-energy imaging using a photon counting detector with electronic spectrum-splitting

NASA Astrophysics Data System (ADS)

Bornefalk, Hans; Lundqvist, Mats

2006-03-01

This paper presents a dual-energy imaging technique optimized for contrast-enhanced mammography using a photon counting detector. Each photon pulse is processed separately in the detector and the addition of an electronic threshold near the middle of the energy range of the x-ray spectrum allows discrimination of high and low energy photons. This effectively makes the detector energy sensitive, and allows the acquisition of high- and low-energy images simultaneously. These high- and low-energy images can be combined to dual-energy images where the anatomical clutter has been suppressed. By setting the electronic threshold close to 33.2 keV (the k-edge of iodine) the system is optimized for dual-energy contrast-enhanced imaging of breast tumors. Compared to other approaches, this method not only eliminates the need for separate exposures that might lead to motion artifacts, it also eliminates the otherwise deteriorating overlap between high- and low-energy spectra. We present phantom dual-energy images acquired on a prototype system to illustrate that the technique is already operational, albeit in its infancy. We also present a theoretical estimation of the potential gain in tumor signal-difference-to-noise ratio when using this electronic spectrum-splitting method as opposed to acquiring the high- and low-energy images separately with double exposures with separate x-ray spectra. Assuming ideal energy sensitive photon counting detectors, we arrive at the conclusion that the signal-difference-to-noise ratio could be increased by 145% at constant dose. We also illustrate our results on synthetic images.

Processing of Fear and Anger Facial Expressions: The Role of Spatial Frequency

PubMed Central

Comfort, William E.; Wang, Meng; Benton, Christopher P.; Zana, Yossi

2013-01-01

Spatial frequency (SF) components encode a portion of the affective value expressed in face images. The aim of this study was to estimate the relative weight of specific frequency spectrum bandwidth on the discrimination of anger and fear facial expressions. The general paradigm was a classification of the expression of faces morphed at varying proportions between anger and fear images in which SF adaptation and SF subtraction are expected to shift classification of facial emotion. A series of three experiments was conducted. In Experiment 1 subjects classified morphed face images that were unfiltered or filtered to remove either low (<8 cycles/face), middle (12–28 cycles/face), or high (>32 cycles/face) SF components. In Experiment 2 subjects were adapted to unfiltered or filtered prototypical (non-morphed) fear face images and subsequently classified morphed face images. In Experiment 3 subjects were adapted to unfiltered or filtered prototypical fear face images with the phase component randomized before classifying morphed face images. Removing mid frequency components from the target images shifted classification toward fear. The same shift was observed under adaptation condition to unfiltered and low- and middle-range filtered fear images. However, when the phase spectrum of the same adaptation stimuli was randomized, no adaptation effect was observed. These results suggest that medium SF components support the perception of fear more than anger at both low and high level of processing. They also suggest that the effect at high-level processing stage is related more to high-level featural and/or configural information than to the low-level frequency spectrum. PMID:23637687

A FPGA implementation for linearly unmixing a hyperspectral image using OpenCL

NASA Astrophysics Data System (ADS)

Guerra, Raúl; López, Sebastián.; Sarmiento, Roberto

2017-10-01

Hyperspectral imaging systems provide images in which single pixels have information from across the electromagnetic spectrum of the scene under analysis. These systems divide the spectrum into many contiguos channels, which may be even out of the visible part of the spectra. The main advantage of the hyperspectral imaging technology is that certain objects leave unique fingerprints in the electromagnetic spectrum, known as spectral signatures, which allow to distinguish between different materials that may look like the same in a traditional RGB image. Accordingly, the most important hyperspectral imaging applications are related with distinguishing or identifying materials in a particular scene. In hyperspectral imaging applications under real-time constraints, the huge amount of information provided by the hyperspectral sensors has to be rapidly processed and analysed. For such purpose, parallel hardware devices, such as Field Programmable Gate Arrays (FPGAs) are typically used. However, developing hardware applications typically requires expertise in the specific targeted device, as well as in the tools and methodologies which can be used to perform the implementation of the desired algorithms in the specific device. In this scenario, the Open Computing Language (OpenCL) emerges as a very interesting solution in which a single high-level synthesis design language can be used to efficiently develop applications in multiple and different hardware devices. In this work, the Fast Algorithm for Linearly Unmixing Hyperspectral Images (FUN) has been implemented into a Bitware Stratix V Altera FPGA using OpenCL. The obtained results demonstrate the suitability of OpenCL as a viable design methodology for quickly creating efficient FPGAs designs for real-time hyperspectral imaging applications.

Evaluation of the oxidative stress of psoriatic fibroblasts based on spectral two-photon fluorescence lifetime imaging

NASA Astrophysics Data System (ADS)

Kapsokalyvas, Dimitrios; Barygina, Victoria; Cicchi, Riccardo; Fiorillo, Claudia; Pavone, Francesco S.

2013-02-01

Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Metabolic activity is increased in the epidermis and the dermis. Oxidative stress is high mainly due to reactive oxygen species (ROS) originating from the skin environment and cellular metabolism. We employed a custom multiphoton microscope coupled with a FLIM setup to image primary culture fibroblast cells from perilesional and lesional psoriatic skin in-vitro. Twophoton excited fluorescence images revealed the morphological differences between healthy and psoriatic fibroblasts. Based on the spectral analysis of the NADH and FAD components the oxidative stress was assessed and found to be higher in psoriatic cells. Furthermore the fluorescence lifetime properties were investigated with a TCSPC FLIM module. Mean fluorescence lifetime was found to be longer in psoriatic lesional cells. Analysis of the fast (τ1) and slow (τ2) decay lifetimes revealed a decrease of the ratio of the contribution of the fast (α1) parameter to the contribution of the slow (α2) parameter. The fluorescence in the examined part of the spectrum is attributed mainly to NADH. The decrease of the ratio (α1)/ (α2) is believed to correlate strongly with the anti-oxidant properties of NADH which can lead to the variation of its population in high ROS environment. This methodology could serve as an index of the oxidative status in cells and furthermore could be used to probe the oxidative stress of tissues in-vivo.

Modular wide spectrum lighting system for diagnosis, conservation, and restoration

NASA Astrophysics Data System (ADS)

Miccoli, Matteo; Melis, Marcello

2013-05-01

In the framework of imaging, lighting systems have always played a key role due to the primary importance of both the uniformity of the illumination and the richness of the emitted spectra. Multispectral imaging, i.e. imaging systems working inside and outside the visible wavelength range, are even more demanding and require to pay further attention to a number of parameters characterizing the lighting system. A critical issue for lighting systems, even in the visible light, is the shape of the emitted spectra and (only in the visible range) the Color Rendering Index. The color we perceive from a surface is our eyes' interpretation of the linear spectral combination of the illuminant spectrum and the surface spectral reflectance. If there is a lack of energy in a portion of the visible spectrum, that portion will turn into black to our eyes (and to whatever instrument) regardless the actual reflectance of the surface. In other words a lack in the exciting energy hides part of the spectral reflectance of the observed subject. Furthermore, the wider is the investigated spectrum, the fewer are the sources of light able to cover such a range. In this paper we show how we solved both the problems of the not uniformity of the light beam, independently on the incident angle, and of the selection of a light source with energy rich and continuous enough emitted spectrum.

Membrane-targeting liquid crystal nanoparticles (LCNPs) for drug delivery

NASA Astrophysics Data System (ADS)

Nag, Okhil K.; Naciri, Jawad; Spillmann, Christopher M.; Delehanty, James B.

2016-03-01

In addition to maintaining the structural integrity of the cell, the plasma membrane regulates multiple important cellular processes, such as endocytosis and trafficking, apoptotic pathways and drug transport. The modulation or tracking of such cellular processes by means of controlled delivery of drugs or imaging agents via nanoscale delivery systems is very attractive. Nanoparticle-mediated delivery systems that mediate long-term residence (e.g., days) and controlled release of the cargoes in the plasma membrane while simultaneously not interfering with regular cellular physiology would be ideal for this purpose. Our laboratory has developed a plasma membrane-targeted liquid crystal nanoparticle (LCNP) formulation that can be loaded with dyes or drugs which can be slowly released from the particle over time. Here we highlight the utility of these nanopreparations for membrane delivery and imaging.

Genetic and Diagnostic Biomarker Development in ASD Toddlers Using Resting State Functional MRI

DTIC Science & Technology

2015-09-01

for public release; distribution unlimited Autism spectrum disorder (ASD); biomarker; early brain development; intrinsic functional brain networks...three large neuroimaging/neurobehavioral datasets to identify brain-imaging based biomarkers for Autism Spectrum Disorders (ASD). At Yale, we focus...neurobehavioral!datasets!in!order!to!identify! brainFimaging!based!biomarkers!for! Autism ! Spectrum ! Disorders !(ASD),!including!1)!BrainMap,! developed!and

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-04-01

This Chandra X-Ray Observatory (CXO) image is a spectrum of a black hole, which is similar to the colorful spectrum of sunlight produced by a prism. The x-rays of interest are shown here recorded in bright stripes that run rightward and leftward from the center of the image. These x-rays are sorted precisely according to their energy with the highest-energy x-rays near the center of the image and the lower-energy x-rays farther out. The spectrum was obtained by using the Low Energy Transmission Grating (LETG), which intercepts x-rays and changes their direction by the amounts that depend sensitively on the x-ray energy. The assembly holds 540 gold transmission gratings. When in place behind the mirrors, the gratings intercept the x-rays reflected from the telescope. The bright spot at the center is due to a fraction of the x-ray radiation that is not deflected by the LETG. The spokes that intersect the central spot and the faint diagonal rays that flank the spectrum itself are artifacts due to the structure that supports the LETG grating elements. (Photo credit: NASA Cfa/J. McClintock et al)

Fourier transform power spectrum is a potential measure of tissue alignment in standard MRI: A multiple sclerosis study.

PubMed

Sharma, Shrushrita; Zhang, Yunyan

2017-01-01

Loss of tissue coherency in brain white matter is found in many neurological diseases such as multiple sclerosis (MS). While several approaches have been proposed to evaluate white matter coherency including fractional anisotropy and fiber tracking in diffusion-weighted imaging, few are available for standard magnetic resonance imaging (MRI). Here we present an image post-processing method for this purpose based on Fourier transform (FT) power spectrum. T2-weighted images were collected from 19 patients (10 relapsing-remitting and 9 secondary progressive MS) and 19 age- and gender-matched controls. Image processing steps included: computation, normalization, and thresholding of FT power spectrum; determination of tissue alignment profile and dominant alignment direction; and calculation of alignment complexity using a new measure named angular entropy. To test the validity of this method, we used a highly organized brain white matter structure, corpus callosum. Six regions of interest were examined from the left, central and right aspects of both genu and splenium. We found that the dominant orientation of each ROI derived from our method was significantly correlated with the predicted directions based on anatomy. There was greater angular entropy in patients than controls, and a trend to be greater in secondary progressive MS patients. These findings suggest that it is possible to detect tissue alignment and anisotropy using traditional MRI, which are routinely acquired in clinical practice. Analysis of FT power spectrum may become a new approach for advancing the evaluation and management of patients with MS and similar disorders. Further confirmation is warranted.

Modeling of polychromatic attenuation using computed tomography reconstructed images

NASA Technical Reports Server (NTRS)

Yan, C. H.; Whalen, R. T.; Beaupre, G. S.; Yen, S. Y.; Napel, S.

1999-01-01

This paper presents a procedure for estimating an accurate model of the CT imaging process including spectral effects. As raw projection data are typically unavailable to the end-user, we adopt a post-processing approach that utilizes the reconstructed images themselves. This approach includes errors from x-ray scatter and the nonidealities of the built-in soft tissue correction into the beam characteristics, which is crucial to beam hardening correction algorithms that are designed to be applied directly to CT reconstructed images. We formulate this approach as a quadratic programming problem and propose two different methods, dimension reduction and regularization, to overcome ill conditioning in the model. For the regularization method we use a statistical procedure, Cross Validation, to select the regularization parameter. We have constructed step-wedge phantoms to estimate the effective beam spectrum of a GE CT-I scanner. Using the derived spectrum, we computed the attenuation ratios for the wedge phantoms and found that the worst case modeling error is less than 3% of the corresponding attenuation ratio. We have also built two test (hybrid) phantoms to evaluate the effective spectrum. Based on these test phantoms, we have shown that the effective beam spectrum provides an accurate model for the CT imaging process. Last, we used a simple beam hardening correction experiment to demonstrate the effectiveness of the estimated beam profile for removing beam hardening artifacts. We hope that this estimation procedure will encourage more independent research on beam hardening corrections and will lead to the development of application-specific beam hardening correction algorithms.

Melt-processed polymeric cellular dosage forms for immediate drug release.

PubMed

Blaesi, Aron H; Saka, Nannaji

2015-12-28

The present immediate-release solid dosage forms, such as the oral tablets and capsules, comprise granular matrices. While effective in releasing the drug rapidly, they are fraught with difficulties inherent in processing particulate matter. By contrast, liquid-based processes would be far more predictable; but the standard cast microstructures are unsuited for immediate-release because they resist fluid percolation and penetration. In this article, we introduce cellular dosage forms that can be readily prepared from polymeric melts by incorporating the nucleation, growth, and coalescence of microscopic gas bubbles in a molding process. We show that the cell topology and formulation of such cellular structures can be engineered to reduce the length-scale of the mass-transfer step, which determines the time of drug release, from as large as the dosage form itself to as small as the thickness of the cell wall. This allows the cellular dosage forms to achieve drug release rates over an order of magnitude faster compared with those of cast matrices, spanning the entire spectrum of immediate-release and beyond. The melt-processed polymeric cellular dosage forms enable predictive design of immediate-release solid dosage forms by tailoring microstructures, and could be manufactured efficiently in a single step.

Spatial luminescence imaging of dopant incorporation in CdTe Films

DOE PAGES

Guthrey, Harvey; Moseley, John; Colegrove, Eric; ...

2017-01-25

State-of-the-art cathodoluminescence (CL) spectrum imaging with spectrum-per-pixel CL emission mapping is applied to spatially profile how dopant elements are incorporated into Cadmium telluride (CdTe). Emission spectra and intensity monitor the spatial distribution of additional charge carriers through characteristic variations in the CL emission based on computational modeling. Our results show that grain boundaries play a role in incorporating dopants in CdTe exposed to copper, phosphorus, and intrinsic point defects in CdTe. Furthermore, the image analysis provides critical, unique feedback to understand dopant incorporation and activation in the inhomogeneous CdTe material, which has struggled to reach high levels of hole density.

Speckle interferometry of asteroids

NASA Technical Reports Server (NTRS)

Drummond, Jack D.; Hege, E. Keith

1989-01-01

Steward Observatory's two-dimensional power spectrum signature analysis of speckle interferometry observations is summarized. Results for six asteroids are presented. The poles and triaxial ellipsoid dimensions of 4 Vesta, 433 Eros, 511 Davida, and 532 Herculina have been previously reported. New results for 2 Pallas and 29 Amphitrite are given, as well as further results for Vesta. Image reconstruction is ultimately required to minimize biasing effects of asteroid surface features on the simpler power spectrum analysis. Preliminary imaging results have been achieved for Vesta and Eros, and images for these two are displayed. Speckle interferometry and radiometry diameters are compared, and diameters from the two occultations of Pallas are addressed.

Visualizing Morphological Changes of Abscission Zone Cells in Arabidopsis by Scanning Electron Microscope.

PubMed

Shi, Chun-Lin; Butenko, Melinka A

2018-01-01

Scanning electron microscope (SEM) is a type of electron microscope which produces detailed images of surface structures. It has been widely used in plants and animals to study cellular structures. Here, we describe a detailed protocol to prepare samples of floral abscission zones (AZs) for SEM, as well as further image analysis. We show that it is a powerful tool to detect morphologic changes at the cellular level during the course of abscission in wild-type plants and to establish the details of phenotypic alteration in abscission mutants.

Live Cell Imaging of a Fluorescent Gentamicin Conjugate

PubMed Central

Escobedo, Jorge O.; Chu, Yu-Hsuan; Wang, Qi; Steyger, Peter S.; Strongin, Robert M.

2012-01-01

Understanding cellular mechanisms of ototoxic and nephrotoxic drug uptake, intracellular distribution, and molecular trafficking across cellular barrier systems aids the study of potential uptake blockers that preserve sensory and renal function during critical life-saving therapy. Herein we report the design, synthesis characterization and evaluation of a fluorescent conjugate of the aminoglycoside antibiotic gentamicin. Live cell imaging results show the potential utility of this new material. Related gentamicin conjugates studied to date quench in live kindney cells, and have been largely restricted to use in fixed (delipidated) cells. PMID:22545403

In vivo 1H-magnetic resonance spectroscopy study of the attentional networks in autism

PubMed Central

Bernardi, Silvia; Anagnostou, Evdokia; Shen, Jun; Kolevzon, Alexander; Buxbaum, Joseph D.; Hollander, Eric; Hof, Patrick R.; Fan, Jin

2010-01-01

Attentional dysfunction is one of the most consistent findings in individuals with autism spectrum disorders (ASD). However, the significance of such findings for the pathophysiology of autism is unclear. In this study, we investigated cellular neurochemistry with proton magnetic resonance spectroscopy imaging (1H-MRS) in brain regions associated with networks subserving alerting, orienting, and executive control of attention in patients with ASD. Concentrations of cerebral N-acetyl-aspartate (NAA), creatinine + phosphocreatinine, choline-containing compounds, myo-inositol (Ins) and glutamate + glutamine (Glx) were determined by 3 T 1H-MRS examinations in 14 high-functioning medication-free adults with a diagnosis of ASD and 14 age- and IQ-matched healthy controls (HC) in the anterior cingulate cortex (ACC), thalamus, temporoparietal junction (TPJ), and areas near or along the intraparietal sulcus (IPS). Compared to HC group, the ASD group showed significantly lower Glx concentrations in right ACC and reduced Ins in left TPJ. This study provides evidence of abnormalities in neurotransmission related to networks subserving executive control and alerting of attention, functions which have been previously implicated in ASD pathogenesis. PMID:21185269

NADPH as a potential intrinsic probe for tumour margin estimation

NASA Astrophysics Data System (ADS)

Stewart, Hazel; Hupp, Ted R.; Birch, David J. S.

2018-03-01

The fluorescent properties of the reduced coenzyme NADH and its phosphorylated derivative (NADPH) have been explored in order to assess their potential as an intrinsic probe for cancer surgery. NADPH production is increased in cancer cells to quench reactive oxygen species and meet higher demands for biosynthesis, and has attractive fluorescent properties such as emission towards the visible part of the spectrum and a relatively long fluorescence lifetime upon binding to enzymes ( 1 - 6.5 ns) that helps discriminate against other endogenous species. Different environmental effects on NAD(P)H fluorescence are reported here, including an increase in lifetime upon oxygen removal, an ability to retain its fluorescent properties in a complex medium (a silica phantom) and its fluorescence lifetime also being distinguishable in a cell environment. In addition, the development of a miniaturized liquid light guide filter-based timecorrelated single photon counting fluorescence lifetime system is reported as a step towards time-resolved visual imaging in cancer surgery. This system has been demonstrated as being capable of accurately measuring NAD(P)H fluorescence lifetimes in both simple solvent and cellular environments.

A near-infrared BSA coated DNA-AgNCs for cellular imaging.

PubMed

Mu, Wei-Yu; Yang, Rui; Robertson, Akrofi; Chen, Qiu-Yun

2018-02-01

Near-infrared silver nanoclusters, have potential applications in the field of biosensing and biological imaging. However, less stability of most DNA-AgNCs limits their application. To obtain stable near-infrared fluorescence DNA-AgNCs for biological imaging, a new kind of near-infrared fluorescent DNA-Ag nanoclusters was constructed using the C3A rich aptamer as a synthesis template, GAG as the enhancer. In particular, a new DNA-AgNCs-Trp@BSA was obtained based on the self-assembly of bovine serum albumin (BSA) and tryptophan loaded DNA-AgNCs by hydrophobic interaction. This self-assembly method can be used to stabilize DNAn-Ag (n = 1-3) nanoclusters. Hence, the near-infrared fluorescence DNA-AgNCs-Trp@BSA was applied in cellular imaging of HepG-2 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Multiphoton luminescent graphene quantum dots for in vivo tracking of human adipose-derived stem cells

NASA Astrophysics Data System (ADS)

Kim, Jin; Song, Sung Ho; Jin, Yoonhee; Park, Hyun-Ji; Yoon, Hyewon; Jeon, Seokwoo; Cho, Seung-Woo

2016-04-01

The applicability of graphene quantum dots (GQDs) for the in vitro and in vivo live imaging and tracking of different types of human stem cells is investigated. GQDs synthesized by the modified graphite intercalated compound method show efficient cellular uptake with improved biocompatibility and highly sensitive optical properties, indicating their feasibility as a bio-imaging probe for stem cell therapy.The applicability of graphene quantum dots (GQDs) for the in vitro and in vivo live imaging and tracking of different types of human stem cells is investigated. GQDs synthesized by the modified graphite intercalated compound method show efficient cellular uptake with improved biocompatibility and highly sensitive optical properties, indicating their feasibility as a bio-imaging probe for stem cell therapy. Electronic supplementary information (ESI) available: Additional results. See DOI: 10.1039/c6nr02143c

A high performance parallel computing architecture for robust image features

NASA Astrophysics Data System (ADS)

Zhou, Renyan; Liu, Leibo; Wei, Shaojun

2014-03-01

A design of parallel architecture for image feature detection and description is proposed in this article. The major component of this architecture is a 2D cellular network composed of simple reprogrammable processors, enabling the Hessian Blob Detector and Haar Response Calculation, which are the most computing-intensive stage of the Speeded Up Robust Features (SURF) algorithm. Combining this 2D cellular network and dedicated hardware for SURF descriptors, this architecture achieves real-time image feature detection with minimal software in the host processor. A prototype FPGA implementation of the proposed architecture achieves 1318.9 GOPS general pixel processing @ 100 MHz clock and achieves up to 118 fps in VGA (640 × 480) image feature detection. The proposed architecture is stand-alone and scalable so it is easy to be migrated into VLSI implementation.

Cryo-FIB-SEM serial milling and block face imaging: Large volume structural analysis of biological tissues preserved close to their native state.

PubMed

Vidavsky, Netta; Akiva, Anat; Kaplan-Ashiri, Ifat; Rechav, Katya; Addadi, Lia; Weiner, Steve; Schertel, Andreas

2016-12-01

Many important biological questions can be addressed by studying in 3D large volumes of intact, cryo fixed hydrated tissues (⩾10,000μm 3 ) at high resolution (5-20nm). This can be achieved using serial FIB milling and block face surface imaging under cryo conditions. Here we demonstrate the unique potential of the cryo-FIB-SEM approach using two extensively studied model systems; sea urchin embryos and the tail fin of zebrafish larvae. We focus in particular on the environment of mineral deposition sites. The cellular organelles, including mitochondria, Golgi, ER, nuclei and nuclear pores are made visible by the image contrast created by differences in surface potential of different biochemical components. Auto segmentation and/or volume rendering of the image stacks and 3D reconstruction of the skeleton and the cellular environment, provides a detailed view of the relative distribution in space of the tissue/cellular components, and thus of their interactions. Simultaneous acquisition of secondary and back-scattered electron images adds additional information. For example, a serial view of the zebrafish tail reveals the presence of electron dense mineral particles inside mitochondrial networks extending more than 20μm in depth in the block. Large volume imaging using cryo FIB SEM, as demonstrated here, can contribute significantly to the understanding of the structures and functions of diverse biological tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

A mini-microscope for in situ monitoring of cells.

PubMed

Kim, Sang Bok; Koo, Kyo-in; Bae, Hojae; Dokmeci, Mehmet R; Hamilton, Geraldine A; Bahinski, Anthony; Kim, Sun Min; Ingber, Donald E; Khademhosseini, Ali

2012-10-21

A mini-microscope was developed for in situ monitoring of cells by modifying off-the-shelf components of a commercial webcam. The mini-microscope consists of a CMOS imaging module, a small plastic lens and a white LED illumination source. The CMOS imaging module was connected to a laptop computer through a USB port for image acquisition and analysis. Due to its compact size, 8 × 10 × 9 cm, the present microscope is portable and can easily fit inside a conventional incubator, and enables real-time monitoring of cellular behaviour. Moreover, the mini-microscope can be used for imaging cells in conventional cell culture flasks, such as Petri dishes and multi-well plates. To demonstrate the operation of the mini-microscope, we monitored the cellular migration of mouse 3T3 fibroblasts in a scratch assay in medium containing three different concentrations of fetal bovine serum (5, 10, and 20%) and demonstrated differential responses depending on serum levels. In addition, we seeded embryonic stem cells inside poly(ethylene glycol) microwells and monitored the formation of stem cell aggregates in real time using the mini-microscope. Furthermore, we also combined a lab-on-a-chip microfluidic device for microdroplet generation and analysis with the mini-microscope and observed the formation of droplets under different flow conditions. Given its cost effectiveness, robust imaging and portability, the presented platform may be useful for a range of applications for real-time cellular imaging using lab-on-a-chip devices at low cost.

A mini-microscope for in situ monitoring of cells†‡

PubMed Central

Kim, Sang Bok; Koo, Kyo-in; Bae, Hojae; Dokmeci, Mehmet R.; Hamilton, Geraldine A.; Bahinski, Anthony; Kim, Sun Min; Ingber, Donald E.

2013-01-01

A mini-microscope was developed for in situ monitoring of cells by modifying off-the-shelf components of a commercial webcam. The mini-microscope consists of a CMOS imaging module, a small plastic lens and a white LED illumination source. The CMOS imaging module was connected to a laptop computer through a USB port for image acquisition and analysis. Due to its compact size, 8 × 10 × 9 cm, the present microscope is portable and can easily fit inside a conventional incubator, and enables real-time monitoring of cellular behaviour. Moreover, the mini-microscope can be used for imaging cells in conventional cell culture flasks, such as Petri dishes and multi-well plates. To demonstrate the operation of the mini-microscope, we monitored the cellular migration of mouse 3T3 fibroblasts in a scratch assay in medium containing three different concentrations of fetal bovine serum (5, 10, and 20%) and demonstrated differential responses depending on serum levels. In addition, we seeded embryonic stem cells inside poly(ethylene glycol) microwells and monitored the formation of stem cell aggregates in real time using the mini-microscope. Furthermore, we also combined a lab-on-a-chip microfluidic device for microdroplet generation and analysis with the mini-microscope and observed the formation of droplets under different flow conditions. Given its cost effectiveness, robust imaging and portability, the presented platform may be useful for a range of applications for real-time cellular imaging using lab-on-a-chip devices at low cost. PMID:22911426

A multi-scale convolutional neural network for phenotyping high-content cellular images.

PubMed

Godinez, William J; Hossain, Imtiaz; Lazic, Stanley E; Davies, John W; Zhang, Xian

2017-07-01

Identifying phenotypes based on high-content cellular images is challenging. Conventional image analysis pipelines for phenotype identification comprise multiple independent steps, with each step requiring method customization and adjustment of multiple parameters. Here, we present an approach based on a multi-scale convolutional neural network (M-CNN) that classifies, in a single cohesive step, cellular images into phenotypes by using directly and solely the images' pixel intensity values. The only parameters in the approach are the weights of the neural network, which are automatically optimized based on training images. The approach requires no a priori knowledge or manual customization, and is applicable to single- or multi-channel images displaying single or multiple cells. We evaluated the classification performance of the approach on eight diverse benchmark datasets. The approach yielded overall a higher classification accuracy compared with state-of-the-art results, including those of other deep CNN architectures. In addition to using the network to simply obtain a yes-or-no prediction for a given phenotype, we use the probability outputs calculated by the network to quantitatively describe the phenotypes. This study shows that these probability values correlate with chemical treatment concentrations. This finding validates further our approach and enables chemical treatment potency estimation via CNNs. The network specifications and solver definitions are provided in Supplementary Software 1. william_jose.godinez_navarro@novartis.com or xian-1.zhang@novartis.com. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Pathological proof of cellular death in radiofrequency ablation therapy and correlation with flash echo imaging--an experiment study.

PubMed

Fujiki, Kei

2004-01-01

The aims of this study were to clarify the geographic distribution of complete cell death in the radiofrequency ablated area in a porcine liver experiment, and to evaluate the efficacy of ultrasonography using contrast media in detecting the area of Radiofrequency-induced cell death. Radiofrequency ablation was performed at 3 sites in each liver in seven swine with a RF2000TM radiofrequency generator using an expandable type needle electrode. The ablation area was investigated histologically by Hematoxylin-Eosin staining and NADH staining. The area of radiofrequency-induced cell death was correlated to the ultrasonographic findings using contrast media, by means of contrast harmonic imaging, flash echo imaging-subtraction and flash echo imaging-power Doppler. The ablation area showed three distinct regions. Although the HE staining did not indicate necrosis, the NADH staining showed a complete loss of cellular activity in the inner and middle layers of the ablation area. However, in the outer layer cells displaying cellular integrity were intermingled with the necrotic cells, indicating that some of the cells in this layer had a chance to survive. Further, in some cases the outer layer of the ablated area had irregular margins. The flash-echo power-doppler images were accurately correlated in size and shape to the pathologically proved region of complete cell death in the radiofrequency-induced lesions. In the marginal part of the radiofrequency ablation area, cell death was incomplete. Flash echo imaging-power doppler was a useful and sensitive real time imaging technique for accurate evaluation of the region of complete cell death.

Monitoring tumor metastases and osteolytic lesions with bioluminescence and micro CT imaging.

PubMed

Lim, Ed; Modi, Kshitij; Christensen, Anna; Meganck, Jeff; Oldfield, Stephen; Zhang, Ning

2011-04-14

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence imaging using IVIS Spectrum was employed to monitor the distribution and development of the tumor cells following the delivery procedure including DLIT reconstruction to measure the tumor signal and its location. Development of metastatic lesions to the bone tissues triggers osteolytic activity and lesions to tibia and femur were evaluated longitudinally using micro CT. Imaging was performed using a Quantum FX micro CT system with fast imaging and low X-ray dose. The low radiation dose allows multiple imaging sessions to be performed with a cumulative X-ray dosage far below LD50. A mouse imaging shuttle device was used to sequentially image the mice with both IVIS Spectrum and Quantum FX achieving accurate animal positioning in both the bioluminescence and CT images. The optical and CT data sets were co-registered in 3-dimentions using the Living Image 4.1 software. This multi-mode approach allows close monitoring of tumor growth and development simultaneously with osteolytic activity.

An interventional multispectral photoacoustic imaging platform for the guidance of minimally invasive procedures

NASA Astrophysics Data System (ADS)

Xia, Wenfeng; Nikitichev, Daniil I.; Mari, Jean Martial; West, Simeon J.; Ourselin, Sebastien; Beard, Paul C.; Desjardins, Adrien E.

2015-07-01

Precise and efficient guidance of medical devices is of paramount importance for many minimally invasive procedures. These procedures include fetal interventions, tumor biopsies and treatments, central venous catheterisations and peripheral nerve blocks. Ultrasound imaging is commonly used for guidance, but it often provides insufficient contrast with which to identify soft tissue structures such as vessels, tumors, and nerves. In this study, a hybrid interventional imaging system that combines ultrasound imaging and multispectral photoacoustic imaging for guiding minimally invasive procedures was developed and characterized. The system provides both structural information from ultrasound imaging and molecular information from multispectral photoacoustic imaging. It uses a commercial linear-array ultrasound imaging probe as the ultrasound receiver, with a multimode optical fiber embedded in a needle to deliver pulsed excitation light to tissue. Co-registration of ultrasound and photoacoustic images is achieved with the use of the same ultrasound receiver for both modalities. Using tissue ex vivo, the system successfully discriminated deep-located fat tissue from the surrounding muscle tissue. The measured photoacoustic spectrum of the fat tissue had good agreement with the lipid spectrum in literature.

Analysis of identification of digital images from a map of cosmic microwaves

NASA Astrophysics Data System (ADS)

Skeivalas, J.; Turla, V.; Jurevicius, M.; Viselga, G.

2018-04-01

This paper discusses identification of digital images from the cosmic microwave background radiation map formed according to the data of the European Space Agency "Planck" telescope by applying covariance functions and wavelet theory. The estimates of covariance functions of two digital images or single images are calculated according to the random functions formed of the digital images in the form of pixel vectors. The estimates of pixel vectors are formed on expansion of the pixel arrays of the digital images by a single vector. When the scale of a digital image is varied, the frequencies of single-pixel color waves remain constant and the procedure for calculation of covariance functions is not affected. For identification of the images, the RGB format spectrum has been applied. The impact of RGB spectrum components and the color tensor on the estimates of covariance functions was analyzed. The identity of digital images is assessed according to the changes in the values of the correlation coefficients in a certain range of values by applying the developed computer program.

Nanogels as imaging agents for modalities spanning the electromagnetic spectrum.

PubMed

Chan, Minnie; Almutairi, Adah

2016-01-21

In the past few decades, advances in imaging equipment and protocols have expanded the role of imaging in in vivo diagnosis and disease management, especially in cancer. Traditional imaging agents have rapid clearance and low specificity for disease detection. To improve accuracy in disease identification, localization and assessment, novel nanomaterials are frequently explored as imaging agents to achieve high detection specificity and sensitivity. A promising material for this purpose are hydrogel nanoparticles, whose high hydrophilicity, biocompatibility, and tunable size in the nanometer range make them ideal for imaging. These nanogels (10 to 200 nm) can circumvent uptake by the reticuloendothelial system, allowing longer circulation times than small molecules. In addition, their size/surface properties can be further tailored to optimize their pharmacokinetics for imaging of a particular disease. Herein, we provide a comprehensive review of nanogels as imaging agents in various modalities with sources of signal spanning the electromagnetic spectrum, including MRI, NIR, UV-vis, and PET. Many materials and formulation methods will be reviewed to highlight the versatility of nanogels as imaging agents.

Clinical and mutational spectrum in Korean patients with Rubinstein-Taybi syndrome: the spectrum of brain MRI abnormalities.

PubMed

Lee, Jin Sook; Byun, Christine K; Kim, Hunmin; Lim, Byung Chan; Hwang, Hee; Choi, Ji Eun; Hwang, Yong Seung; Seong, Moon-Woo; Park, Sung Sup; Kim, Ki Joong; Chae, Jong-Hee

2015-04-01

Rubinstein-Taybi syndrome (RSTS) is one of the neurodevelopmental disorders caused by mutations of epigenetic genes. The CREBBP gene is the most common causative gene, encoding the CREB-binding protein with histone acetyltransferase (HAT) activity, an epigenetic modulator. To date, there have been few reports on the structural abnormalities of the brain in RSTS patients. In addition, there are no reports on the analysis of CREBBP mutations in Korean RSTS patients. We performed mutational analyses on 16 unrelated patients with RSTS, with diagnosis based on the typical clinical features. Their medical records and brain MRI images were reviewed retrospectively. Ten of 16 patients (62.5%) had mutations in the CREBBP gene. The mutations included five frameshift mutations (31.2%), two nonsense mutations (12.5%), and three multiexon deletions (18.8%). There were no remarkable significant differences in the clinical features between those with and without a CREBBP mutation, although brain MRI abnormalities were more frequently observed in those with a CREBBP mutation. Seven of 10 patients in whom brain imaging was performed had structural abnormalities, including Chiari malformation type 1, thinning of the corpus callosum, and delayed myelination. There were no differences in delayed development or cognitive impairment between those with and without abnormal brain images, while epilepsy was involved in two patients who had abnormalities on brain MRI images. We investigated the spectrum of CREBBP mutations in Korean patients with RSTS for the first time. Eight novel mutations extended the genetic spectrum of CREBBP mutations in RSTS patients. This is also the first study showing the prevalence and spectrum of abnormalities on brain MRI in RSTS patients. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Endoscopic probe optics for spectrally encoded confocal microscopy.

PubMed

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

2013-01-01

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

Dual-modality, fluorescent, PLGA encapsulated bismuth nanoparticles for molecular and cellular fluorescence imaging and computed tomography.

PubMed

Swy, Eric R; Schwartz-Duval, Aaron S; Shuboni, Dorela D; Latourette, Matthew T; Mallet, Christiane L; Parys, Maciej; Cormode, David P; Shapiro, Erik M

2014-11-07

Reports of molecular and cellular imaging using computed tomography (CT) are rapidly increasing. Many of these reports use gold nanoparticles. Bismuth has similar CT contrast properties to gold while being approximately 1000-fold less expensive. Herein we report the design, fabrication, characterization, and CT and fluorescence imaging properties of a novel, dual modality, fluorescent, polymer encapsulated bismuth nanoparticle construct for computed tomography and fluorescence imaging. We also report on cellular internalization and preliminary in vitro and in vivo toxicity effects of these constructs. 40 nm bismuth(0) nanocrystals were synthesized and encapsulated within 120 nm Poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles by oil-in-water emulsion methodologies. Coumarin-6 was co-encapsulated to impart fluorescence. High encapsulation efficiency was achieved ∼70% bismuth w/w. Particles were shown to internalize within cells following incubation in culture. Bismuth nanocrystals and PLGA encapsulated bismuth nanoparticles exhibited >90% and >70% degradation, respectively, within 24 hours in acidic, lysosomal environment mimicking media and both remained nearly 100% stable in cytosolic/extracellular fluid mimicking media. μCT and clinical CT imaging was performed at multiple X-ray tube voltages to measure concentration dependent attenuation rates as well as to establish the ability to detect the nanoparticles in an ex vivo biological sample. Dual fluorescence and CT imaging is demonstrated as well. In vivo toxicity studies in rats revealed neither clinically apparent side effects nor major alterations in serum chemistry and hematology parameters. Calculations on minimal detection requirements for in vivo targeted imaging using these nanoparticles are presented. Indeed, our results indicate that these nanoparticles may serve as a platform for sensitive and specific targeted molecular CT and fluorescence imaging.

Multivariate statistical analysis of low-voltage EDS spectrum images

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

Anderson, I.M.

1998-03-01

Whereas energy-dispersive X-ray spectrometry (EDS) has been used for compositional analysis in the scanning electron microscope for 30 years, the benefits of using low operating voltages for such analyses have been explored only during the last few years. This paper couples low-voltage EDS with two other emerging areas of characterization: spectrum imaging and multivariate statistical analysis. The specimen analyzed for this study was a finished Intel Pentium processor, with the polyimide protective coating stripped off to expose the final active layers.

Advances in Biomedical Imaging, Bioengineering, and Related Technologies for the Development of Biomarkers of Pancreatic Disease: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases and National Institute of Biomedical Imaging and Bioengineering Workshop

PubMed Central

Kelly, Kimberly A.; Hollingsworth, Michael A.; Brand, Randall E.; Liu, Christina H.; Singh, Vikesh K.; Srivastava, Sudhir; Wasan, Ajay D.; Yadav, Dhiraj; Andersen, Dana K.

2015-01-01

A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Institute of Biomedical Imaging and Bioengineering focused on research gaps and opportunities in the development of new biomarkers of pancreatic disease. The session was held on July 22, 2015, and structured into six sessions: 1) introduction and overview, 2) keynote address, 3) new approaches to the diagnosis of chronic pancreatitis, 4) biomarkers of pain and inflammation, 5) new approaches to the detection of pancreatic cancer, and 6) shed exosomes, shed cells, and shed proteins. Recent advances in the fields of pancreatic imaging, functional markers of pancreatic disease, proteomics, molecular and cellular imaging, and detection of circulating cancer cells and exosomes were reviewed. Knowledge gaps and research needs were highlighted. The development of new methods for the non-invasive determination of pancreatic pathology, the use of cellular markers of pancreatic function, inflammation, pain, and malignancy, and the refinement of methods to identify cells and cellular constituents of pancreatic cancer were discussed. The further refinement of sophisticated technical methods, and the need for clinical studies to validate these new approaches in large-scale studies of patients at risk for the development of pancreatic disease was repeatedly emphasized. PMID:26465948

Multiscale image analysis reveals structural heterogeneity of the cell microenvironment in homotypic spheroids.

PubMed

Schmitz, Alexander; Fischer, Sabine C; Mattheyer, Christian; Pampaloni, Francesco; Stelzer, Ernst H K

2017-03-03

Three-dimensional multicellular aggregates such as spheroids provide reliable in vitro substitutes for tissues. Quantitative characterization of spheroids at the cellular level is fundamental. We present the first pipeline that provides three-dimensional, high-quality images of intact spheroids at cellular resolution and a comprehensive image analysis that completes traditional image segmentation by algorithms from other fields. The pipeline combines light sheet-based fluorescence microscopy of optically cleared spheroids with automated nuclei segmentation (F score: 0.88) and concepts from graph analysis and computational topology. Incorporating cell graphs and alpha shapes provided more than 30 features of individual nuclei, the cellular neighborhood and the spheroid morphology. The application of our pipeline to a set of breast carcinoma spheroids revealed two concentric layers of different cell density for more than 30,000 cells. The thickness of the outer cell layer depends on a spheroid's size and varies between 50% and 75% of its radius. In differently-sized spheroids, we detected patches of different cell densities ranging from 5 × 10 5 to 1 × 10 6  cells/mm 3 . Since cell density affects cell behavior in tissues, structural heterogeneities need to be incorporated into existing models. Our image analysis pipeline provides a multiscale approach to obtain the relevant data for a system-level understanding of tissue architecture.