WorldWideScience

Sample records for enable dual-alternating-color fluorescence

  1. Quantum dot blueing and blinking enables fluorescence nanoscopy.

    Science.gov (United States)

    Hoyer, Patrick; Staudt, Thorsten; Engelhardt, Johann; Hell, Stefan W

    2011-01-12

    We demonstrate superresolution fluorescence imaging of cells using bioconjugated CdSe/ZnS quantum dot markers. Fluorescence blueing of quantum dot cores facilitates separation of blinking markers residing closer than the diffraction barrier. The high number of successively emitted photons enables ground state depletion microscopy followed by individual marker return with a resolving power of the size of a single dot (∼12 nm). Nanoscale imaging is feasible with a simple webcam.

  2. Fluorescence Immunoassay System via Enzyme-Enabled in Situ Synthesis of Fluorescent Silicon Nanoparticles.

    Science.gov (United States)

    Sun, Jian; Hu, Tao; Chen, Chuanxia; Zhao, Dan; Yang, Fan; Yang, Xiurong

    2016-10-04

    The emergence of fluorescent nanomaterials with excellent performances has triggered the development of fluorescence analysis technique, which possesses several advantages in the research and clinical applications. However, current strategies for fluorescence immunoassay usually involve the routine fluorophore-labeled antibody and/or awkward signal generation procedure that may not be available in conventional enzyme-linked immunosorbent assay (ELISA) systems. Herein, we circumvent this problem by imparting an exquisite signal generation mechanism to commercially available alkaline phosphatase (ALP)-based ELISA platform and putting forward a conceptual fluorescent ELISA system based on an original ALP-enabled in situ synthesis of fluorescent nanomaterials. After adding target antigen, the presence of ALP labeled on antibody catalyzes the transformation of the substrate ascorbic acid 2-phosphate into ascorbic acid. Then the resultant ascorbic acid (i.e., ascorbate) interacts with amine-containing silane molecules (no fluorescence) to produce intense cyan fluorescent silicon nanoparticles. For the proof-of-concept, alpha-fetoprotein and human immunoglobulin G are chosen as the model antigen targets, and our proposed immunoassay (designated as the nanoparticles generation-based fluorescent ELISA) enables the detection with either fluorescence spectroscopy or naked-eye readout under the ultraviolet lamp. The convincing recognition mechanism and assay performance ensure fluorescent ELISA to quantitatively evaluate the alpha-fetoprotein level in serologic test and potentially apply in the clinic diagnosis of hepatocellular carcinoma.

  3. Fast Dynamic Visualizations in Microfluidics Enabled by Fluorescent Carbon Nanodots.

    Science.gov (United States)

    Huang, Yi; Xiao, Lian; An, Tingting; Lim, Wenxiang; Wong, Teckneng; Sun, Handong

    2017-09-01

    Microfluidic systems have become a superior platform for explorations of fascinating fluidic physics at microscale as well as applications in biomedical devices, chemical reactions, drug delivery, etc. Exploitations of this platform are built upon the fundamental techniques of flow visualizations. However, the currently employed fluorescent materials for microfluidic visualization are far from satisfaction, which severely hinders their widespread applications. Here fluorescent carbon nanodots are documented as a game-changer, applicable in versatile fluidic environment for the visualization in microfluidics with unprecedented advantages. One of the fastest fluorescent imaging speeds up to 2500 frames per second under a normal contionous wave (CW) laser line is achieved by adopting carbon nanodots in microfluidics. Besides better visualizations of the fluid or interface, fluorescent carbon nanodots-based microparticles enable quantitative studies of high speed dynamics in fluids at microscale with a more than 90% lower cost, which is inaccessible by traditionally adopted fluorescent dye based seeding particles. The findings hold profound influences to microfluidic investigations and may even lead to revolutionary changes to the relevant industries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Fluorescent biosensors enabled by graphene and graphene oxide.

    Science.gov (United States)

    Zhang, Huan; Zhang, Honglu; Aldalbahi, Ali; Zuo, Xiaolei; Fan, Chunhai; Mi, Xianqiang

    2017-03-15

    During the past few years, graphene and graphene oxide (GO) have attracted numerous attentions for the potential applications in various fields from energy technology, biosensing to biomedical diagnosis and therapy due to their various functionalization, high volume surface ratio, unique physical and electrical properties. Among which, graphene and graphene oxide based fluorescent biosensors enabled by their fluorescence-quenching properties have attracted great interests. The fluorescence of fluorophore or dye labeled on probes (such as molecular beacon, aptamer, DNAzymes and so on) was quenched after adsorbed on to the surface of graphene. While in the present of the targets, due to the strong interactions between probes and targets, the probes were detached from the surface of graphene, generating dramatic fluorescence, which could be used as signals for detection of the targets. This strategy was simple and economy, together with great programmable abilities of probes; we could realize detection of different kinds of species. In this review, we first briefly introduced the history of graphene and graphene oxide, and then summarized the fluorescent biosensors enabled by graphene and GO, with a detailed account of the design mechanism and comparison with other nanomaterials (e.g. carbon nanotubes and gold nanoparticles). Following that, different sensing platforms for detection of DNAs, ions, biomolecules and pathogens or cells as well as the cytotoxicity issue of graphene and GO based in vivo biosensing were further discussed. We hope that this review would do some help to researchers who are interested in graphene related biosening research work. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Smartphone-enabled filterless fluorescence assay utilizing the pyrene excimer

    Science.gov (United States)

    Goertz, John P.; White, Ian M.

    2015-03-01

    Fluorescence microscopy offers a number of advantages for cell- and biomarker-based diagnostics with regards to ease of use and interpretation, sensitivity, and specificity. However, its use in low-resource settings is often hindered by the need for bulky microscopes with expensive excitation and filter setups. While many advances have been made towards utilizing smartphones as microscopes, there remains a reliance on complex attachments to facilitate fluorescence microscopy. Here, we report progress towards a filter-less fluorescent assay utilizing ultraviolet light, an unmodified smartphone, and pyrene-labeled aptamers. The pyrene monomer is excited at a wavelength of 350 nm and emits at approximately 390 nm; when two pyrene molecules are brought into close proximity, however, they form an excimer which emits at approximately 490 nm. We have engineered pyrene-conjugated DNA sequences such that the fluorophores, normally in monomeric configuration, are brought into proximity upon binding of the DNA to its target. The large Stokes shift between excitation and emission of the excimer allows us to detect such biorecognition events with an unfiltered smartphone camera, enabling the use of this assay in low-resource settings where portability and easeof- use are paramount.

  6. Total internal reflection fluorescence based multiplane localization microscopy enables super-resolved volume imaging

    Science.gov (United States)

    Mondal, Partha Pratim; Hess, Samuel T.

    2017-05-01

    Total internal reflection fluorescence (TIRF) based geometry is attractive for super-resolution localization microscopy. Although the traditional TIRF configuration enables near-surface 2D imaging, it is not capable of imaging multiple axial planes. We propose a simultaneous multiplane imaging based localization encoded (SMILE) technique in the TIRF configuration that utilizes point spread function (PSF) information (PSF size, corresponding to single molecules located at the focal plane and off-focal planes, and the detected photons per PSF) to reconstruct a near-surface volume stack. The natural spread of the detection PSFs (far from the specimen-coverslip interface) is used to fix the axial locations of single molecules, and the corresponding photon count determines their localization precision. The proposed SMILE microscopy technique enables super-resolved volume reconstruction based on 2D recorded data.

  7. Force-activatable biosensor enables single platelet force mapping directly by fluorescence imaging.

    Science.gov (United States)

    Wang, Yongliang; LeVine, Dana N; Gannon, Margaret; Zhao, Yuanchang; Sarkar, Anwesha; Hoch, Bailey; Wang, Xuefeng

    2018-02-15

    Integrin-transmitted cellular forces are critical for platelet adhesion, activation, aggregation and contraction during hemostasis and thrombosis. Measuring and mapping single platelet forces are desired in both research and clinical applications. Conventional force-to-strain based cell traction force microscopies have low resolution which is not ideal for cellular force mapping in small platelets. To enable platelet force mapping with submicron resolution, we developed a force-activatable biosensor named integrative tension sensor (ITS) which directly converts molecular tensions to fluorescent signals, therefore enabling cellular force mapping directly by fluorescence imaging. With ITS, we mapped cellular forces in single platelets at 0.4µm resolution. We found that platelet force distribution has strong polarization which is sensitive to treatment with the anti-platelet drug tirofiban, suggesting that the ITS force map can report anti-platelet drug efficacy. The ITS also calibrated integrin molecular tensions in platelets and revealed two distinct tension levels: 12-54 piconewton (nominal values) tensions generated during platelet adhesion and tensions above 54 piconewton generated during platelet contraction. Overall, the ITS is a powerful biosensor for the study of platelet mechanobiology, and holds great potential in antithrombotic drug development and assessing platelet activity in health and disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Stable J-aggregation enabled dual photoacoustic and fluorescence nanoparticles for intraoperative cancer imaging

    Science.gov (United States)

    Shakiba, Mojdeh; Ng, Kenneth K.; Huynh, Elizabeth; Chan, Harley; Charron, Danielle M.; Chen, Juan; Muhanna, Nidal; Foster, F. Stuart; Wilson, Brian C.; Zheng, Gang

    2016-06-01

    J-aggregates display nanoscale optical properties which enable their use in fluorescence and photoacoustic imaging applications. However, control over their optical properties in an in vivo setting is hampered by the conformational lability of the J-aggregate structure in complex biological environments. J-aggregating nanoparticles (JNP) formed by self-assembly of bacteriopheophorbide-lipid (Bchl-lipid) in lipid nanovesicles represents a novel strategy to stabilize J-aggregates for in vivo bioimaging applications. We find that 15 mol% Bchl-lipid embedded within a saturated phospholipid bilayer vesicle was optimal in terms of maximizing Bchl-lipid dye loading, while maintaining a spherical nanoparticle morphology and retaining spectral properties characteristic of J-aggregates. The addition of cholesterol maintains the stability of the J-aggregate absorption band for up to 6 hours in the presence of 90% FBS. In a proof-of-concept experiment, we successfully applied JNPs as a fluorescence contrast agent for real-time intraoperative detection of metastatic lymph nodes in a rabbit head-and-neck cancer model. Lymph node metastasis delineation was further verified by visualizing the JNP within the excised lymph node using photoacoustic imaging. Using JNPs, we demonstrate the possibility of using J-aggregates as fluorescence and photoacoustic contrast agents and may potentially spur the development of other nanomaterials that can stably induce J-aggregation for in vivo cancer bioimaging applications.J-aggregates display nanoscale optical properties which enable their use in fluorescence and photoacoustic imaging applications. However, control over their optical properties in an in vivo setting is hampered by the conformational lability of the J-aggregate structure in complex biological environments. J-aggregating nanoparticles (JNP) formed by self-assembly of bacteriopheophorbide-lipid (Bchl-lipid) in lipid nanovesicles represents a novel strategy to stabilize J

  9. Live imaging of endogenous PSD-95 using ENABLED: a conditional strategy to fluorescently label endogenous proteins.

    Science.gov (United States)

    Fortin, Dale A; Tillo, Shane E; Yang, Guang; Rah, Jong-Cheol; Melander, Joshua B; Bai, Suxia; Soler-Cedeño, Omar; Qin, Maozhen; Zemelman, Boris V; Guo, Caiying; Mao, Tianyi; Zhong, Haining

    2014-12-10

    Stoichiometric labeling of endogenous synaptic proteins for high-contrast live-cell imaging in brain tissue remains challenging. Here, we describe a conditional mouse genetic strategy termed endogenous labeling via exon duplication (ENABLED), which can be used to fluorescently label endogenous proteins with near ideal properties in all neurons, a sparse subset of neurons, or specific neuronal subtypes. We used this method to label the postsynaptic density protein PSD-95 with mVenus without overexpression side effects. We demonstrated that mVenus-tagged PSD-95 is functionally equivalent to wild-type PSD-95 and that PSD-95 is present in nearly all dendritic spines in CA1 neurons. Within spines, while PSD-95 exhibited low mobility under basal conditions, its levels could be regulated by chronic changes in neuronal activity. Notably, labeled PSD-95 also allowed us to visualize and unambiguously examine otherwise-unidentifiable excitatory shaft synapses in aspiny neurons, such as parvalbumin-positive interneurons and dopaminergic neurons. Our results demonstrate that the ENABLED strategy provides a valuable new approach to study the dynamics of endogenous synaptic proteins in vivo. Copyright © 2014 the authors 0270-6474/14/3416698-15$15.00/0.

  10. Novel Application of Fluorescence Lifetime and Fluorescence Microscopy Enables Quantitative Access to Subcellular Dynamics in Plant Cells

    Science.gov (United States)

    Elgass, Kirstin; Caesar, Katharina; Schleifenbaum, Frank; Stierhof, York-Dieter; Meixner, Alfred J.; Harter, Klaus

    2009-01-01

    Background Optical and spectroscopic technologies working at subcellular resolution with quantitative output are required for a deeper understanding of molecular processes and mechanisms in living cells. Such technologies are prerequisite for the realisation of predictive biology at cellular and subcellular level. However, although established in the physical sciences, these techniques are rarely applied to cell biology in the plant sciences. Principal Findings Here, we present a combined application of one-chromophore fluorescence lifetime microscopy and wavelength-selective fluorescence microscopy to analyse the function of a GFP fusion of the Brassinosteroid Insensitive 1 Receptor (BRI1-GFP) with high spatial and temporal resolution in living Arabidopsis cells in their tissue environment. We show a rapid, brassinolide-induced cell wall expansion and a fast BR-regulated change in the BRI1-GFP fluorescence lifetime in the plasmamembrane in vivo. Both cell wall expansion and changes in fluorescence lifetime reflect early BR-induced and BRI1-dependent physiological or signalling processes. Our experiments also show the potential of one-chromophore fluorescence lifetime microscopy for the in vivo monitoring of the biochemical and biophysical subcellular environment using GFP fusion proteins as probes. Significance One-chromophore fluorescence lifetime microscopy, combined with wavelength-specific fluorescence microscopy, opens up new frontiers for in vivo dynamic and quantitative analysis of cellular processes at high resolution which are not addressable by pure imaging technologies or transmission electron microscopy. PMID:19492078

  11. Imaging transient formation of diffusion layers with fluorescence-enabled electrochemical microscopy.

    Science.gov (United States)

    Oja, Stephen M; Zhang, Bo

    2014-12-16

    Fluorescence-enabled electrochemical microscopy (FEEM) is demonstrated as a new technique to image transient concentration profiles of redox species generated on ultramicroelectrodes (UMEs). FEEM converts an electrical signal into an optical signal by electrically coupling a conventional redox reaction to a fluorogenic reporter reaction on a closed bipolar electrode. We describe the implementation of FEEM for diffusion layer imaging and use an array of thousands of parallel bipolar electrodes to image the diffusion layers of UMEs in two and three dimensions. This new technique provides a way to image an entire 2-dimensional lateral cross section of a dynamic diffusion layer in a single experiment. By taking several of these lateral cross sections at different axial positions in the diffusion layer, a 3-dimensional image of the diffusion layer can be built. We image the diffusion layer of a 10 μm diameter carbon fiber electrode over the course of a cyclic voltammetry experiment and compare the FEEM-generated images to concentration profiles generated from numerical simulation. We also image the diffusion layer of a two electrode array consisting of two 10 μm diameter carbon fibers over the course of a potential step experiment.

  12. Optically sectioned wide-field fluorescence lifetime imaging endoscopy enabled by structured illumination (Conference Presentation)

    Science.gov (United States)

    Hinsdale, Taylor; Malik, Bilal H.; Rico-Jimenez, Jose J.; Jo, Javier A.; Maitland, Kristen C.

    2016-03-01

    We present a wide-field fluorescence lifetime imaging (FLIM) system with optical sectioning by structured illumination microscopy (SIM). FLIM measurements were made using a time gated ICCD camera in conjunction with a pulsed nitrogen dye laser operating at 450 nm. Intensity images were acquired at multiple time delays from a trigger initiated by a laser pulse to create a wide-field FLIM image, which was then combined with three phase SIM to provide optical sectioning. Such a mechanism has the potential to increase the reliability and accuracy of the FLIM measurements by rejecting background intensity. SIM also provides the opportunity to create volumetric FLIM images with the incorporation of scanning mechanisms for the sample plane. We present multiple embodiments of such a system: one as a free space endoscope and the other as a fiber microendoscope enabled by the introduction of a fiber bundle. Finally, we demonstrate the efficacy of such an imaging system by imaging dyes embedded in a tissue phantom.

  13. Optically sectioned wide-field fluorescence lifetime imaging microscopy enabled by structured illumination

    Science.gov (United States)

    Hinsdale, Taylor; Olsovsky, Cory; Rico-Jimenez, Jose J.; Maitland, Kristen C.; Jo, Javier A.; Malik, Bilal H.

    2017-01-01

    In this paper, we demonstrate the ability of structured illumination microscopy to enhance the ability of fluorescence lifetime imaging to resolve fluorescence lifetimes in relatively thick samples that possess distinct but spectrally overlapping fluorescent layers. Structured illumination fluorescent lifetime imaging microscopy (SI-FLIM) is shown to be able to accurately reconstruct lifetime values in homogenous fluorophore samples (POPOP, NADH, and FAD) as well as accurately measure fluorescent lifetime in two layer models that are layered with NADH/FAD over POPOP, where NADH/FAD and POPOP have spectral overlap. Finally, the ability of SI-FLIM was demonstrated in a hamster cheek pouch ex vivo to show that more accurate lifetimes could be measured for each layer of interest in the oral mucosa (epithelium and submucosa). PMID:28663841

  14. Investigating dye performance and crosstalk in fluorescence enabled bioimaging using a model system.

    Directory of Open Access Journals (Sweden)

    Riikka Arppe

    Full Text Available Detailed imaging of biological structures, often smaller than the diffraction limit, is possible in fluorescence microscopy due to the molecular size and photophysical properties of fluorescent probes. Advances in hardware and multiple providers of high-end bioimaging makes comparing images between studies and between research groups very difficult. Therefore, we suggest a model system to benchmark instrumentation, methods and staining procedures. The system we introduce is based on doped zeolites in stained polyvinyl alcohol (PVA films: a highly accessible model system which has the properties needed to act as a benchmark in bioimaging experiments. Rather than comparing molecular probes and imaging methods in complicated biological systems, we demonstrate that the model system can emulate this complexity and can be used to probe the effect of concentration, brightness, and cross-talk of fluorophores on the detected fluorescence signal. The described model system comprises of lanthanide (III ion doped Linde Type A zeolites dispersed in a PVA film stained with fluorophores. We tested: F18, MitoTracker Red and ATTO647N. This model system allowed comparing performance of the fluorophores in experimental conditions. Importantly, we here report considerable cross-talk of the dyes when exchanging excitation and emission settings. Additionally, bleaching was quantified. The proposed model makes it possible to test and benchmark staining procedures before these dyes are applied to more complex biological systems.

  15. Fluorescent nanodiamonds enable quantitative tracking of human mesenchymal stem cells in miniature pigs

    Science.gov (United States)

    Su, Long-Jyun; Wu, Meng-Shiue; Hui, Yuen Yung; Chang, Be-Ming; Pan, Lei; Hsu, Pei-Chen; Chen, Yit-Tsong; Ho, Hong-Nerng; Huang, Yen-Hua; Ling, Thai-Yen; Hsu, Hsao-Hsun; Chang, Huan-Cheng

    2017-03-01

    Cell therapy is a promising strategy for the treatment of human diseases. While the first use of cells for therapeutic purposes can be traced to the 19th century, there has been a lack of general and reliable methods to study the biodistribution and associated pharmacokinetics of transplanted cells in various animal models for preclinical evaluation. Here, we present a new platform using albumin-conjugated fluorescent nanodiamonds (FNDs) as biocompatible and photostable labels for quantitative tracking of human placenta choriodecidual membrane-derived mesenchymal stem cells (pcMSCs) in miniature pigs by magnetic modulation. With this background-free detection technique and time-gated fluorescence imaging, we have been able to precisely determine the numbers as well as positions of the transplanted FND-labeled pcMSCs in organs and tissues of the miniature pigs after intravenous administration. The method is applicable to single-cell imaging and quantitative tracking of human stem/progenitor cells in rodents and other animal models as well.

  16. Novel implantable imaging system for enabling simultaneous multiplanar and multipoint analysis for fluorescence potentiometry in the visual cortex.

    Science.gov (United States)

    Kobayashi, Takuma; Motoyama, Mayumi; Masuda, Hiroyuki; Ohta, Yasumi; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Tamura, Hideki; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2012-01-01

    Techniques for fast, noninvasive measurement of neuronal excitability within a broad area will be of major importance for analyzing and understanding neuronal networks and animal behavior in neuroscience field. In this research, a novel implantable imaging system for fluorescence potentiometry was developed using a complementary metal-oxide semiconductor (CMOS) technology, and its application to the analysis of cultured brain slices and the brain of a living mouse is described. A CMOS image sensor, small enough to be implanted into the brain, with light-emitting diodes and an absorbing filter was developed to enable real-time fluorescence imaging. The sensor, in conjunction with a voltage-sensitive dye, was certainly able to visualize the potential statuses of neurons and obtain physiological responses in both right and left visual cortex simultaneously by using multiple sensors for the first time. This accomplished multiplanar and multipoint measurement provides multidimensional information from different aspects. The light microsensors do not disturb the animal behavior. This implies that the imaging system can combine functional fluorescence imaging in the brain with behavioral experiments in a freely moving animal. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. A Parallel Distributed-Memory Particle Method Enables Acquisition-Rate Segmentation of Large Fluorescence Microscopy Images.

    Directory of Open Access Journals (Sweden)

    Yaser Afshar

    Full Text Available Modern fluorescence microscopy modalities, such as light-sheet microscopy, are capable of acquiring large three-dimensional images at high data rate. This creates a bottleneck in computational processing and analysis of the acquired images, as the rate of acquisition outpaces the speed of processing. Moreover, images can be so large that they do not fit the main memory of a single computer. We address both issues by developing a distributed parallel algorithm for segmentation of large fluorescence microscopy images. The method is based on the versatile Discrete Region Competition algorithm, which has previously proven useful in microscopy image segmentation. The present distributed implementation decomposes the input image into smaller sub-images that are distributed across multiple computers. Using network communication, the computers orchestrate the collectively solving of the global segmentation problem. This not only enables segmentation of large images (we test images of up to 10(10 pixels, but also accelerates segmentation to match the time scale of image acquisition. Such acquisition-rate image segmentation is a prerequisite for the smart microscopes of the future and enables online data compression and interactive experiments.

  18. A Parallel Distributed-Memory Particle Method Enables Acquisition-Rate Segmentation of Large Fluorescence Microscopy Images.

    Science.gov (United States)

    Afshar, Yaser; Sbalzarini, Ivo F

    2016-01-01

    Modern fluorescence microscopy modalities, such as light-sheet microscopy, are capable of acquiring large three-dimensional images at high data rate. This creates a bottleneck in computational processing and analysis of the acquired images, as the rate of acquisition outpaces the speed of processing. Moreover, images can be so large that they do not fit the main memory of a single computer. We address both issues by developing a distributed parallel algorithm for segmentation of large fluorescence microscopy images. The method is based on the versatile Discrete Region Competition algorithm, which has previously proven useful in microscopy image segmentation. The present distributed implementation decomposes the input image into smaller sub-images that are distributed across multiple computers. Using network communication, the computers orchestrate the collectively solving of the global segmentation problem. This not only enables segmentation of large images (we test images of up to 10(10) pixels), but also accelerates segmentation to match the time scale of image acquisition. Such acquisition-rate image segmentation is a prerequisite for the smart microscopes of the future and enables online data compression and interactive experiments.

  19. Fluorescence Imaging Enabled Urethane-Doped Citrate-Based Biodegradable Elastomers

    Science.gov (United States)

    Zhang, Yi; Tran, Richard T.; Qattan, Ibrahim; Tsai, Yi-ting; Tang, Liping; Liu, Chao; Yang, Jian

    2013-01-01

    The field of tissue engineering and drug delivery calls for new measurement tools, non-invasive real-time assays, and design methods for the next wave of innovations. Based on our recent progress in developing intrinsically biodegradable photoluminescent polymers (BPLPs) without conjugating organic dyes or quantum dots, in this paper, we developed a new type urethane-doped biodegradable photoluminescent polymers (UBPLPs) that could potentially serve as a new tool to respond the above call for innovations. Inherited from BPLPs, UBPLPs demonstrated strong inherent photoluminescence and excellent cytocompatibility in vitro. Crosslinked UBPLPs (CUBPLPs) showed soft, elastic, but strong mechanical properties with a tensile strength as high as 49.41±6.17 MPa and a corresponding elongation at break of 334.87±26.31%. Porous triphasic CUBPLP vascular scaffolds showed a burst pressure of 769.33±70.88 mmHg and a suture retention strength of 1.79±0.11 N. Stable but photoluminescent nanoparticles with average size of 103 nm were also obtained by nanoprecipitation. High loading efficiency (91.84%) and sustained release of 5-fluorouracil (up to 120 h) were achieved from UBPLP nanoparticles. With a quantum yield as high as 38.65%, both triphasic scaffold and nanoparticle solutions could be non-invasively detected in vivo. UBPLPs represent an innovation in fluorescent biomaterial design and may offer great potential in advancing the field of tissue engineering and drug delivery where bioimaging has gained increasing interest. PMID:23465824

  20. Irving Langmuir Prize Talk: Single-Molecule Fluorescence Imaging: Nanoscale Emitters with Photoinduced Switching Enable Superresolution.

    Science.gov (United States)

    Moerner, W. E.

    2009-03-01

    In the two decades since the first optical detection and spectroscopy of a single molecule in a solid (Phys. Rev. Lett. 62, 2535 (1989)), much has been learned about the ability of single molecules to probe local nanoenvironments and individual behavior in biological and nonbiological materials in the absence of ensemble averaging that can obscure heterogeneity. The early years concentrated on high-resolution spectroscopy in solids, which provided observations of lifetime-limited spectra, optical saturation, spectral diffusion, optical switching, vibrational spectra, and magnetic resonance of a single molecular spin. In the mid-1990's, much of the field moved to room temperature, where a wide variety of biophysical effects were subsequently explored, but it is worth noting that several features from the low-temperature studies have analogs at high temperature. For example, in our first studies of yellow-emitting variants of green fluorescent protein (EYFP) in the water-filled pores of a gel (Nature 388, 355 (1997)), optically induced switching of the emission was observed, a room-temperature analog of the earlier low-temperature behavior. Because each single fluorophore acts a light source roughly 1 nm in size, microscopic imaging of individual fluorophores leads naturally to superlocalization, or determination of the position of the molecule with precision beyond the optical diffraction limit, simply by digitization of the point-spread function from the single emitter. Recent work has allowed measurement of the shape of single filaments in a living cell simply by allowing a single molecule to move through the filament (PNAS 103, 10929 (2006)). The additional use of photoinduced control of single-molecule emission allows imaging beyond the diffraction limit (superresolution) by several novel approaches proposed by different researchers. For example, using photoswitchable EYFP, a novel protein superstructure can now be directly imaged in a living bacterial cell at

  1. Discovery of PF-06928215 as a high affinity inhibitor of cGAS enabled by a novel fluorescence polarization assay

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Justin; Brault, Amy; Vincent, Fabien; Weng, Shawn; Wang, Hong; Dumlao, Darren; Aulabaugh, Ann; Aivazian, Dikran; Castro, Dana; Chen, Ming; Culp, Jeffrey; Dower, Ken; Gardner, Joseph; Hawrylik, Steven; Golenbock, Douglas; Hepworth, David; Horn, Mark; Jones, Lyn; Jones, Peter; Latz, Eicke; Li, Jing; Lin, Lih-Ling; Lin, Wen; Lin, David; Lovering, Frank; Niljanskul, Nootaree; Nistler, Ryan; Pierce, Betsy; Plotnikova, Olga; Schmitt, Daniel; Shanker, Suman; Smith, James; Snyder, William; Subashi, Timothy; Trujillo, John; Tyminski, Edyta; Wang, Guoxing; Wong, Jimson; Lefker, Bruce; Dakin, Leslie; Leach, Karen; Nakano, Hiroyasu

    2017-09-21

    Cyclic GMP-AMP synthase (cGAS) initiates the innate immune system in response to cytosolic dsDNA. After binding and activation from dsDNA, cGAS uses ATP and GTP to synthesize 2', 3' -cGAMP (cGAMP), a cyclic dinucleotide second messenger with mixed 2'-5' and 3'-5' phosphodiester bonds. Inappropriate stimulation of cGAS has been implicated in autoimmune disease such as systemic lupus erythematosus, thus inhibition of cGAS may be of therapeutic benefit in some diseases; however, the size and polarity of the cGAS active site makes it a challenging target for the development of conventional substrate-competitive inhibitors. We report here the development of a high affinity (KD = 200 nM) inhibitor from a low affinity fragment hit with supporting biochemical and structural data showing these molecules bind to the cGAS active site. We also report a new high throughput cGAS fluorescence polarization (FP)-based assay to enable the rapid identification and optimization of cGAS inhibitors. This FP assay uses Cy5-labelled cGAMP in combination with a novel high affinity monoclonal antibody that specifically recognizes cGAMP with no cross reactivity to cAMP, cGMP, ATP, or GTP. Given its role in the innate immune response, cGAS is a promising therapeutic target for autoinflammatory disease. Our results demonstrate its druggability, provide a high affinity tool compound, and establish a high throughput assay for the identification of next generation cGAS inhibitors.

  2. Bio-optimized energy transfer in densely packed fluorescent protein enables near-maximal luminescence and solid-state lasers.

    Science.gov (United States)

    Gather, Malte C; Yun, Seok Hyun

    2014-12-08

    Bioluminescent organisms are likely to have an evolutionary drive towards high radiance. As such, bio-optimized materials derived from them hold great promise for photonic applications. Here, we show that biologically produced fluorescent proteins retain their high brightness even at the maximum density in solid state through a special molecular structure that provides optimal balance between high protein concentration and low resonance energy transfer self-quenching. Dried films of green fluorescent protein show low fluorescence quenching (-7 dB) and support strong optical amplification (gnet=22 cm(-1); 96 dB cm(-1)). Using these properties, we demonstrate vertical cavity surface emitting micro-lasers with low threshold (lasers) and self-assembled all-protein ring lasers. Moreover, solid-state blends of different proteins support efficient Förster resonance energy transfer, with sensitivity to intermolecular distance thus allowing all-optical sensing. The design of fluorescent proteins may be exploited for bio-inspired solid-state luminescent molecules or nanoparticles.

  3. A Bright Fluorescent Probe for H2S Enables Analyte-Responsive, 3D Imaging in Live Zebrafish Using Light Sheet Fluorescence Microscopy.

    Science.gov (United States)

    Hammers, Matthew D; Taormina, Michael J; Cerda, Matthew M; Montoya, Leticia A; Seidenkranz, Daniel T; Parthasarathy, Raghuveer; Pluth, Michael D

    2015-08-19

    Hydrogen sulfide (H2S) is a critical gaseous signaling molecule emerging at the center of a rich field of chemical and biological research. As our understanding of the complexity of physiological H2S in signaling pathways evolves, advanced chemical and technological investigative tools are required to make sense of this interconnectivity. Toward this goal, we have developed an azide-functionalized O-methylrhodol fluorophore, MeRho-Az, which exhibits a rapid >1000-fold fluorescence response when treated with H2S, is selective for H2S over other biological analytes, and has a detection limit of 86 nM. Additionally, the MeRho-Az scaffold is less susceptible to photoactivation than other commonly used azide-based systems, increasing its potential application in imaging experiments. To demonstrate the efficacy of this probe for H2S detection, we demonstrate the ability of MeRho-Az to detect differences in H2S levels in C6 cells and those treated with AOAA, a common inhibitor of enzymatic H2S synthesis. Expanding the use of MeRho-Az to complex and heterogeneous biological settings, we used MeRho-Az in combination with light sheet fluorescence microscopy (LSFM) to visualize H2S in the intestinal tract of live zebrafish. This application provides the first demonstration of analyte-responsive 3D imaging with LSFM, highlighting the utility of combining new probes and live imaging methods for investigating chemical signaling in complex multicellular systems.

  4. Research and Development of a New Field Enhanced Low Temperature Thermionic Cathode that Enables Fluorescent Dimming and Loan Shedding without Auxiliary Cathode Heating

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jin

    2009-01-07

    This is the final report for project entitled 'Research and development of a new field enhanced low temperature thermionic cathode that enables fluorescent dimming and load shedding without auxiliary cathode heating', under Agreement Number: DE-FC26-04NT-42329. Under this project, a highly efficient CNT based thermionic cathode was demonstrated. This cathode is capable of emitting electron at a current density two order of magnitude stronger then a typical fluorescent cathode at same temperatures, or capable of emitting at same current density but at temperature about 300 C lower than that of a fluorescent cathode. Detailed fabrication techniques were developed including CVD growth of CNTs and sputter deposition of oxide thin films on CNTs. These are mature technologies that have been widely used in industry for large scale materials processing and device fabrications, thus, with further development work, the techniques developed in this project can be scaled-up in manufacturing environment. The prototype cathodes developed in this project were tested in lighting plasma discharge environment. In many cases, they not only lit and sustain the plasma, but also out perform the fluorescent cathodes in key parameters such like cathode fall voltages. More work will be needed to further evaluate more detailed and longer term performance of the prototype cathode in lighting plasma.

  5. Fluorescent sensors for the basic metabolic panel enable measurement with a smart phone device over the physiological range.

    Science.gov (United States)

    Awqatty, Becker; Samaddar, Shayak; Cash, Kevin J; Clark, Heather A; Dubach, J Matthew

    2014-10-21

    The advanced functionality of portable devices such as smart phones provides the necessary hardware to potentially perform complex diagnostic measurements in any setting. Recent research and development have utilized cameras and data acquisition properties of smart phones to create diagnostic approaches for a variety of diseases or pollutants. However, in concentration measurements, such as blood glucose, the performance of handheld diagnostic devices depends largely on the sensing mechanism. To expand measurements to multiple components, often necessary in medical tests, with a single diagnostic device, robust platform based sensors are needed. Here, we developed a suite of dual wavelength fluorescent sensors with response characteristics necessary to measure each component of a basic metabolic panel, a common clinical measurement. Furthermore, the response of these sensors could be measured with a simple optical setup to convert a smart phone into a fluorescence measurement instrument. This approach could be used as a mobile basic metabolic panel measurement system for point of care diagnostics.

  6. Nile Red fluorescence spectrum decomposition enables rapid screening of large protein aggregates in complex biopharmaceutical formulations like influenza vaccines.

    Science.gov (United States)

    Sahin, Ziya; Akkoc, Senem; Neeleman, Ronald; Haines, Jonathan; Kayser, Veysel

    2017-05-25

    The extensive presence of large (high molecular weight) protein aggregates in biopharmaceutical formulations is a concern for formulation stability and possibly safety. Tests to screen large aggregate content in such bioformulations are therefore needed for rapid and reliable quality control in industrial settings. Herein, non-commercial seasonal influenza split-virus vaccine samples, produced using various strains and extracted from selected industrial processing steps, were used as model complex bioformulations. Orthogonal characterization through transmission electron microscopy, UV-Vis absorption spectroscopy, fluorescence emission spectroscopy, high-performance liquid chromatography and single-radial immunodiffusion revealed that large, amorphous protein aggregates are formed after virus splitting and their presence is linked mainly, albeit not only, to surfactant (Triton X-100) content in a sample. Importantly, the presence of large virus aggregates in purified whole virus samples and large protein aggregates in vaccine samples was found to correlate with broadening/shouldering in Nile Red fluorescence spectra. Accordingly, decomposition of Nile Red spectra into components allowed the development of a novel, rapid, reliable and user-friendly test with high-throughput potential for screening large aggregate content in influenza split-virus vaccines. The test can be adapted for screening other complex biopharmaceutical formulations, provided relevant controls are done for informed decomposition of fluorescence spectra into their components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Epithelial cell-targeted transgene expression enables isolation of cyan fluorescent protein (CFP)-expressing prostate stem/progenitor cells.

    Science.gov (United States)

    Peng, Weidan; Bao, Yunhua; Sawicki, Janet A

    2011-10-01

    To establish a method for efficient and relatively easy isolation of a cell population containing epithelial prostate stem cells, we developed two transgenic mouse models, K5/CFP and K18/RFP. In these models, promoters of the cytokeratin 5 (Krt5) and the cytokeratin 18 (Krt18) genes regulate cyan and red fluorescent proteins (CFP and RFP), respectively. CFP and RFP reporter protein fluorescence allows for visualization of K5(+) and K18(+) epithelial cells within the cellular spatial context of the prostate gland and for their direct isolation by FACS. Using these models, it is possible to test directly the stem cell properties of prostate epithelial cell populations that are positively selected based on expression of cytoplasmic proteins, K5 and K18. After validating appropriate expression of the K5/CFP and K18/RFP transgenes in the developing and adult prostate, we demonstrate that a subset of CFP-expressing prostate cells exhibits stem cell proliferation potential and differentiation capabilities. Then, using prostate cells sorted from double transgenic mice (K5/CFP + K18/RFP), we compare RNA microarrays of sorted K5(+)K18(+) basal and K5(-)K18(+) luminal epithelial cells, and identify genes that are differentially expressed. Several genes that are over-expressed in K5(+) cells have previously been identified as potential stem cell markers. These results suggest that FACS isolation of prostate cells from these mice based on combining reporter gene fluorescence with expression of potential stem cell surface marker proteins will yield populations of cells enriched for stem cells to a degree that has not been attained by using cell surface markers alone.

  8. Microencapsulation of inorganic nanocrystals into PLGA microsphere vaccines enables their intracellular localization in dendritic cells by electron and fluorescence microscopy.

    Science.gov (United States)

    Schliehe, Christopher; Schliehe, Constanze; Thiry, Marc; Tromsdorf, Ulrich I; Hentschel, Joachim; Weller, Horst; Groettrup, Marcus

    2011-05-10

    Biodegradable poly-(D,L-lactide-co-glycolide) microspheres (PLGA-MS) are approved as a drug delivery system in humans and represent a promising antigen delivery device for immunotherapy against cancer. Immune responses following PLGA-MS vaccination require cross-presentation of encapsulated antigen by professional antigen presenting cells (APCs). While the potential of PLGA-MS as vaccine formulations is well established, the intracellular pathway of cross-presentation following phagocytosis of PLGA-MS is still under debate. A part of the controversy stems from the difficulty in unambiguously identifying PLGA-MS within cells. Here we show a novel strategy for the efficient encapsulation of inorganic nanocrystals (NCs) into PLGA-MS as a tool to study their intracellular localization. We microencapsulated NCs as an electron dense marker to study the intracellular localization of PLGA-MS by transmission electron microscopy (TEM) and as fluorescent labels for confocal laser scanning microscopy. Using this method, we found PLGA-MS to be rapidly taken up by dendritic cells and macrophages. Co-localization with the lysosomal marker LAMP1 showed a lysosomal storage of PLGA-MS for over two days after uptake, long after the initiation of cross-presentation had occurred. Our data argue against an escape of PLGA-MS from the endosome as has previously been suggested as a mechanism to facilitate cross-presentation of PLGA-MS encapsulated antigen. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Synchrotron-based X-ray fluorescence microscopy enables multiscale spatial visualization of ions involved in fungal lignocellulose deconstruction

    Science.gov (United States)

    Kirker, Grant; Zelinka, Sam; Gleber, Sophie-Charlotte; Vine, David; Finney, Lydia; Chen, Si; Hong, Young Pyo; Uyarte, Omar; Vogt, Stefan; Jellison, Jody; Goodell, Barry; Jakes, Joseph E.

    2017-01-01

    The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fungal metabolism, has implications for diverse research disciplines ranging from plant pathology and forest ecology, to carbon sequestration. Despite the importance of ions in fungal decay mechanisms, the spatial distribution and quantification of ions in lignocellulosic cell walls and fungal hyphae during decay is not known. Here we employ synchrotron-based X-ray fluorescence microscopy (XFM) to map and quantify physiologically relevant ions, such as K, Ca, Mn, Fe, and Zn, in wood being decayed by the model brown rot fungus Serpula lacrymans. Two-dimensional XFM maps were obtained to study the ion spatial distributions from mm to submicron length scales in wood, fungal hyphae with the dried extracellular matrix (ECM) from the fungus, and Ca oxalate crystals. Three-dimensional ion volume reconstructions were also acquired of wood cell walls and hyphae with ECM. Results show that the fungus actively transports some ions, such as Fe, into the wood and controls the distribution of ions at both the bulk wood and cell wall length scales. These measurements provide new insights into the movement of ions during decay and illustrate how synchrotron-based XFM is uniquely suited study these ions.

  10. Correcting transmission losses in short-wave infrared spatially offset Raman spectroscopy measurements to enable reduced fluorescence through-barrier detection.

    Science.gov (United States)

    Hopkins, R J; Lee, L; Shand, N C

    2017-09-25

    Spatially offset Raman spectroscopy (SORS) is a proven technique for sub-surface detection. SORS is able to separate Raman signals from a container and its contents, thereby demonstrating application to through-barrier detection for defence and security. Whilst SORS has been demonstrated to reduce fluorescence from the barrier (or surface), fluorescence from the sample (or sub-surface) can still be problematic for some materials when using Raman excitation wavelengths typical in commercially available instrumentation (e.g. 785 nm). Previous work has demonstrated that short-wave infrared (SWIR) excited SORS (e.g. 1064 nm) can reduce fluorescence from the sample and barrier, thereby providing the potential to detect a wider range of materials through a wider range of barriers. In this paper we highlight an additional challenge for detection through some plastic container materials (e.g. high density polyethylene (HDPE) and other opaque plastics) that absorb and scatter both incident and Raman scattered photons in the SWIR band, leading to distortion of the resultant SORS spectrum. The existence of this effect and its impact is explored, along with a potential solution to overcome this challenge that uses multi-wavelength Raman excitation to avoid the detrimental HDPE absorption region.

  11. Adaptive-optics SLO imaging combined with widefield OCT and SLO enables precise 3D localization of fluorescent cells in the mouse retina.

    Science.gov (United States)

    Zawadzki, Robert J; Zhang, Pengfei; Zam, Azhar; Miller, Eric B; Goswami, Mayank; Wang, Xinlei; Jonnal, Ravi S; Lee, Sang-Hyuck; Kim, Dae Yu; Flannery, John G; Werner, John S; Burns, Marie E; Pugh, Edward N

    2015-06-01

    Adaptive optics scanning laser ophthalmoscopy (AO-SLO) has recently been used to achieve exquisite subcellular resolution imaging of the mouse retina. Wavefront sensing-based AO typically restricts the field of view to a few degrees of visual angle. As a consequence the relationship between AO-SLO data and larger scale retinal structures and cellular patterns can be difficult to assess. The retinal vasculature affords a large-scale 3D map on which cells and structures can be located during in vivo imaging. Phase-variance OCT (pv-OCT) can efficiently image the vasculature with near-infrared light in a label-free manner, allowing 3D vascular reconstruction with high precision. We combined widefield pv-OCT and SLO imaging with AO-SLO reflection and fluorescence imaging to localize two types of fluorescent cells within the retinal layers: GFP-expressing microglia, the resident macrophages of the retina, and GFP-expressing cone photoreceptor cells. We describe in detail a reflective afocal AO-SLO retinal imaging system designed for high resolution retinal imaging in mice. The optical performance of this instrument is compared to other state-of-the-art AO-based mouse retinal imaging systems. The spatial and temporal resolution of the new AO instrumentation was characterized with angiography of retinal capillaries, including blood-flow velocity analysis. Depth-resolved AO-SLO fluorescent images of microglia and cone photoreceptors are visualized in parallel with 469 nm and 663 nm reflectance images of the microvasculature and other structures. Additional applications of the new instrumentation are discussed.

  12. Thermal oxidation process accelerates degradation of the olive oil mixed with sunflower oil and enables its discrimination using synchronous fluorescence spectroscopy and chemometric analysis.

    Science.gov (United States)

    Mabood, Fazal; Boqué, Ricard; Folcarelli, Rita; Busto, Olga; Al-Harrasi, Ahmed; Hussain, Javid

    2015-05-15

    We have investigated the effect of thermal treatment on the discrimination of pure extra virgin olive oil (EVOO) samples from EVOO samples adulterated with sunflower oil. Two groups of samples were used. One group was analyzed at room temperature (25°C) and the other group was thermally treated in a thermostatic water bath at 75°C for 8h, in contact with air and with light exposure, to favor oxidation. All samples were then measured with synchronous fluorescence spectroscopy. Fluorescence spectra were acquired by varying the excitation wavelength in the region from 250 to 720nm. In order to optimize the differences between excitation and emission wavelengths, four constant differential wavelengths, i.e., 20nm, 40nm, 60nm and 80nm, were tried. Partial least-squares discriminant analysis (PLS-DA) was used to discriminate between pure and adulterated oils. It was found that the 20nm difference was the optimal, at which the discrimination models showed the best results. The best PLS-DA models were those built with the difference spectra (75-25°C), which were able to discriminate pure from adulterated oils at a 2% level of adulteration. Furthermore, PLS regression models were built to quantify the level of adulteration. Again, the best model was the one built with the difference spectra, with a prediction error of 1.75% of adulteration. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Thermal oxidation process accelerates degradation of the olive oil mixed with sunflower oil and enables its discrimination using synchronous fluorescence spectroscopy and chemometric analysis

    Science.gov (United States)

    Mabood, Fazal; Boqué, Ricard; Folcarelli, Rita; Busto, Olga; Al-Harrasi, Ahmed; Hussain, Javid

    2015-05-01

    We have investigated the effect of thermal treatment on the discrimination of pure extra virgin olive oil (EVOO) samples from EVOO samples adulterated with sunflower oil. Two groups of samples were used. One group was analyzed at room temperature (25 °C) and the other group was thermally treated in a thermostatic water bath at 75 °C for 8 h, in contact with air and with light exposure, to favor oxidation. All samples were then measured with synchronous fluorescence spectroscopy. Fluorescence spectra were acquired by varying the excitation wavelength in the region from 250 to 720 nm. In order to optimize the differences between excitation and emission wavelengths, four constant differential wavelengths, i.e., 20 nm, 40 nm, 60 nm and 80 nm, were tried. Partial least-squares discriminant analysis (PLS-DA) was used to discriminate between pure and adulterated oils. It was found that the 20 nm difference was the optimal, at which the discrimination models showed the best results. The best PLS-DA models were those built with the difference spectra (75-25 °C), which were able to discriminate pure from adulterated oils at a 2% level of adulteration. Furthermore, PLS regression models were built to quantify the level of adulteration. Again, the best model was the one built with the difference spectra, with a prediction error of 1.75% of adulteration.

  14. Evaluation of a new optic-enabled portable X-ray fluorescence spectrometry instrument for measuring toxic metals/metalloids in consumer goods and cultural products

    Science.gov (United States)

    Guimarães, Diana; Praamsma, Meredith L.; Parsons, Patrick J.

    2016-08-01

    X-ray fluorescence spectrometry (XRF) is a rapid, non-destructive multi-elemental analytical technique used for determining elemental contents ranging from percent down to the μg/g level. Although detection limits are much higher for XRF compared to other laboratory-based methods, such as inductively coupled plasma mass spectrometry (ICP-MS), ICP-optical emission spectrometry (OES) and atomic absorption spectrometry (AAS), its portability and ease of use make it a valuable tool, especially for field-based studies. A growing necessity to monitor human exposure to toxic metals and metalloids in consumer goods, cultural products, foods and other sample types while performing the analysis in situ has led to several important developments in portable XRF technology. In this study, a new portable XRF analyzer based on the use of doubly curved crystal optics (HD Mobile®) was evaluated for detecting toxic elements in foods, medicines, cosmetics and spices used in many Asian communities. Two models of the HD Mobile® (a pre-production and a final production unit) were investigated. Performance parameters including accuracy, precision and detection limits were characterized in a laboratory setting using certified reference materials (CRMs) and standard solutions. Bias estimates for key elements of public health significance such as As, Cd, Hg and Pb ranged from - 10% to 11% for the pre-production, and - 14% to 16% for the final production model. Five archived public health samples including herbal medicine products, ethnic spices and cosmetic products were analyzed using both XRF instruments. There was good agreement between the pre-production and final production models for the four key elements, such that the data were judged to be fit-for-purpose for the majority of samples analyzed. Detection of the four key elements of interest using the HD Mobile® was confirmed using archived samples for which ICP-OES data were available based on digested sample materials. The HD

  15. Sputum direct fluorescent antibody (DFA)

    Science.gov (United States)

    ... ency/article/003553.htm Sputum direct fluorescent antibody (DFA) test To use the sharing features on this page, please enable JavaScript. Sputum direct fluorescent antibody (DFA) is a lab test that looks for micro- ...

  16. Fundamentals of fluorescence and fluorescence microscopy.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    This chapter discusses the fundamental physics of fluorescence. The application of fluorescence to microscopy represents an important transition in the development of microscopy, particularly as it applies to biology. It enables quantitating the amounts of specific molecules within a cell, determining whether molecules are complexing on a molecular level, measuring changes in ionic concentrations within cells and organelles, and measuring molecular dynamics. This chapter also discusses the issues important to quantitative measurement of fluorescence and focuses on four of quantitative measurements of fluorescence--boxcar-gated detection, streak cameras, photon correlation, and phase modulation. Although quantitative measurement presents many pitfalls to the beginner, it also presents significant opportunities to one skilled in the art. This chapter also examines how fluorescence is measured in the steady state and time domain and how fluorescence is applied in the modern epifluorescence microscope. Copyright © 2007 Elsevier Inc. All rights reserved.

  17. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...... the foundations of the fluorescence phenomenon, introduces some general methodologies and provides selected examples on applications focused to disentangle structural and dynamical aspects of biological processes....

  18. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements

    OpenAIRE

    Bobin George Abraham; Karen S Sarkisyan; Mishin, Alexander S.; Ville Santala; Tkachenko, Nikolai V.; Matti Karp

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicit...

  19. Two-photon excited hemoglobin fluorescence

    OpenAIRE

    Zheng, Wei; Li, Dong; Zeng, Yan; Luo, Yi; Qu, Jianan Y.

    2010-01-01

    We discovered that hemoglobin emits high energy Soret fluorescence when two-photon excited by the visible femtosecond light sources. The unique spectral and temporal characteristics of hemoglobin fluorescence were measured by using a time-resolved spectroscopic detection system. The high energy Soret fluorescence of hemoglobin shows the spectral peak at 438 nm with extremely short lifetime. This discovery enables two-photon excitation fluorescence microscopy to become a potentially powerful t...

  20. Chemometric endogenous fluorescence for tissue diagnosis

    Science.gov (United States)

    Li, Run; Vasquez, Kevin; Xu, M.

    2017-02-01

    Endogenous fluorescence is a powerful technique for probing both structure and function of tissue. We show that enabling wide-field fluorescence microscopy with chemometrics can significantly enhance the performance of tissue diagnosis with endogenous fluorescence. The spatial distribution and absolute concentration of fluorophores is uncovered with non-negative factorization aided by the spatial diversity from microscopic autofluorescence color images. Fluorescence quantification in terms of its absolute concentration map avoids issues dependent on specific measurement approach or systems and yields biologically meaningful data. The standardization of endogenous fluorescence in terms of absolute concentration will facilitate its translation to the clinics and simplifies the assessment of competing methods relating to tissue fluorescence.

  1. Fluorescent labelling in living cells.

    Science.gov (United States)

    Schneider, Anselm Fabian Lowell; Hackenberger, Christian Peter Richard

    2017-12-01

    The labelling of proteins with green fluorescent protein enabled the visualization of proteins in living cells for the first time. Since then, much progress has been made in the field. Modern strategies allow the labelling of proteins in live cells through a range of specialized methods with sophisticated chemical probes that show enhanced photophysical properties compared to fluorescent proteins. This review briefly summarizes recent advances in the field of fluorescent chemical protein labelling inside living cells and illustrates key aspects on the requirements and advantages of each given method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Fluorescence lifetime based bioassays

    Science.gov (United States)

    Meyer-Almes, Franz-Josef

    2017-12-01

    Fluorescence lifetime (FLT) is a robust intrinsic property and material constant of fluorescent matter. Measuring this important physical indicator has evolved from a laboratory curiosity to a powerful and established technique for a variety of applications in drug discovery, medical diagnostics and basic biological research. This distinct trend was mainly driven by improved and meanwhile affordable laser and detection instrumentation on the one hand, and the development of suitable FLT probes and biological assays on the other. In this process two essential working approaches emerged. The first one is primarily focused on high throughput applications employing biochemical in vitro assays with no requirement for high spatial resolution. The second even more dynamic trend is the significant expansion of assay methods combining highly time and spatially resolved fluorescence data by fluorescence lifetime imaging. The latter approach is currently pursued to enable not only the investigation of immortal tumor cell lines, but also specific tissues or even organs in living animals. This review tries to give an actual overview about the current status of FLT based bioassays and the wide range of application opportunities in biomedical and life science areas. In addition, future trends of FLT technologies will be discussed.

  3. Fluorescence microscopy.

    Science.gov (United States)

    Sanderson, Michael J; Smith, Ian; Parker, Ian; Bootman, Martin D

    2014-10-01

    Fluorescence microscopy is a major tool with which to monitor cell physiology. Although the concepts of fluorescence and its optical separation using filters remain similar, microscope design varies with the aim of increasing image contrast and spatial resolution. The basics of wide-field microscopy are outlined to emphasize the selection, advantages, and correct use of laser scanning confocal microscopy, two-photon microscopy, scanning disk confocal microscopy, total internal reflection, and super-resolution microscopy. In addition, the principles of how these microscopes form images are reviewed to appreciate their capabilities, limitations, and constraints for operation. © 2014 Cold Spring Harbor Laboratory Press.

  4. NOVEL FLUORESCENT PROBES FOR THE DOPAMINE TRANSPORTER

    DEFF Research Database (Denmark)

    Cha, J; Vægter, Christian Bjerggaard; Adkins, Erica

    To enable visualization of the dopamine transporter (DAT) through fluorescence technologies we have synthesized a novel series of fluorescently tagged analogs of cocaine. Previous structure-activity relationship (SAR) studies have demonstrated that the dopamine transporter (DAT) can tolerate...... in untransfected control cells. The possibility of using these ligands for direct labeling of the DAT in living cells represents a new and important approach for understanding cellular targeting and trafficking of the DAT. Moreover, these fluorescent ligands might also provide the molecular tools...

  5. Organising to Enable Innovation

    DEFF Research Database (Denmark)

    Brink, Tove

    2016-01-01

    The purpose of this conceptual paper is to reveal how organising can enable innovation across organisational layers and organisational units. This approach calls for a cross-disciplinary literature review. The aim is to provide an integrated understanding of innovation in an organisational approach....... The findings reveal a continous organising process between individual/ team creativity and organisational structures/control to enable innovation at firm level. Organising provides a dynamic approach and contains the integrated reconstruction of creativity, structures and boundaries for enhanced balance...... of explorative and exploitative learning in uncertain environments. Shedding light on the cross-disciplinary theories to organise innovation provides a contribution at the firm level to enable innovation....

  6. Plasmonics Enhanced Smartphone Fluorescence Microscopy

    KAUST Repository

    Wei, Qingshan

    2017-05-12

    Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.

  7. Plasmonics Enhanced Smartphone Fluorescence Microscopy.

    Science.gov (United States)

    Wei, Qingshan; Acuna, Guillermo; Kim, Seungkyeum; Vietz, Carolin; Tseng, Derek; Chae, Jongjae; Shir, Daniel; Luo, Wei; Tinnefeld, Philip; Ozcan, Aydogan

    2017-05-18

    Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.

  8. Fluorescent probes and fluorescence (microscopy) techniques--illuminating biological and biomedical research.

    Science.gov (United States)

    Drummen, Gregor P C

    2012-11-28

    Fluorescence, the absorption and re-emission of photons with longer wavelengths, is one of those amazing phenomena of Nature. Its discovery and utilization had, and still has, a major impact on biological and biomedical research, since it enables researchers not just to visualize normal physiological processes with high temporal and spatial resolution, to detect multiple signals concomitantly, to track single molecules in vivo, to replace radioactive assays when possible, but also to shed light on many pathobiological processes underpinning disease states, which would otherwise not be possible. Compounds that exhibit fluorescence are commonly called fluorochromes or fluorophores and one of these fluorescent molecules in particular has significantly enabled life science research to gain new insights in virtually all its sub-disciplines: Green Fluorescent Protein. Because fluorescent proteins are synthesized in vivo, integration of fluorescent detection methods into the biological system via genetic techniques now became feasible. Currently fluorescent proteins are available that virtually span the whole electromagnetic spectrum. Concomitantly, fluorescence imaging techniques were developed, and often progress in one field fueled innovation in the other. Impressively, the properties of fluorescence were utilized to develop new assays and imaging modalities, ranging from energy transfer to image molecular interactions to imaging beyond the diffraction limit with super-resolution microscopy. Here, an overview is provided of recent developments in both fluorescence imaging and fluorochrome engineering, which together constitute the “fluorescence toolbox” in life science research.

  9. Fluorescent Probes and Fluorescence (Microscopy Techniques — Illuminating Biological and Biomedical Research

    Directory of Open Access Journals (Sweden)

    Gregor P. C. Drummen

    2012-11-01

    Full Text Available Fluorescence, the absorption and re-emission of photons with longer wavelengths, is one of those amazing phenomena of Nature. Its discovery and utilization had, and still has, a major impact on biological and biomedical research, since it enables researchers not just to visualize normal physiological processes with high temporal and spatial resolution, to detect multiple signals concomitantly, to track single molecules in vivo, to replace radioactive assays when possible, but also to shed light on many pathobiological processes underpinning disease states, which would otherwise not be possible. Compounds that exhibit fluorescence are commonly called fluorochromes or fluorophores and one of these fluorescent molecules in particular has significantly enabled life science research to gain new insights in virtually all its sub-disciplines: Green Fluorescent Protein. Because fluorescent proteins are synthesized in vivo, integration of fluorescent detection methods into the biological system via genetic techniques now became feasible. Currently fluorescent proteins are available that virtually span the whole electromagnetic spectrum. Concomitantly, fluorescence imaging techniques were developed, and often progress in one field fueled innovation in the other. Impressively, the properties of fluorescence were utilized to develop new assays and imaging modalities, ranging from energy transfer to image molecular interactions to imaging beyond the diffraction limit with super-resolution microscopy. Here, an overview is provided of recent developments in both fluorescence imaging and fluorochrome engineering, which together constitute the “fluorescence toolbox” in life science research.

  10. The Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, T.; Nygren, C.; Slaug, B.

    2014-01-01

    This study addresses development of a content-valid cross-Nordic version of the Housing Enabler and investigation of its inter-rater reliability when used in occupational therapy rating situations, involving occupational therapists, clients, and their home environments. The instrument...... was translated from the original Swedish version of the Housing Enabler, and adapted according to accessibility norms and guidelines for housing design in Sweden, Denmark, Finland, and Iceland. This iterative process involved occupational therapists, architects, building engineers, and professional translators...... Enabler. Inter-rater reliability was calculated by means of percentage agreement and kappa statistics. Overall good percentage agreement for the personal and environmental components of the instrument was shown, indicating that the instrument was sufficiently reliable for application in practice...

  11. The Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, Tina; Slaug, Bjørn; Brandt, Åse

    2010-01-01

    This study addresses development of a content valid cross-Nordic version of the Housing Enabler and investigation of its inter-rater reliability when used in occupational therapy rating situations, involving occupational therapists, clients and their home environments. The instrument was translated...... from the original Swedish version of the Housing Enabler, and adapted according to accessibility norms and guidelines for housing design in Sweden, Denmark, Finland and Iceland. This iterative process involved occupational therapists, architects, building engineers and professional translators...... Enabler. Inter-rater reliability was calculated by means of percentage agreement and kappa statistics. Overall good percentage agreement for the personal and environmental components of the instrument was shown, indicating that the instrument was sufficiently reliable for application in practice...

  12. Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, Tina; Brandt, Åse

    2009-01-01

    , however, the built environment shows serious deficits when it comes to accessibility. This study addresses development of a content valid cross-Nordic version of the Housing Enabler and investigation of inter-rater reliability, when used in occupational therapy practice. The instrument was translated from...... statistics. Overall good percentage agreement for all parts of the instrument was shown, indicating that the Nordic Housing Enabler is sufficiently reliable for application in practice and research in the Nordic context. The kappa results varied and possible explanations are discussed, which should be kept......Development and reliability testing of the Nordic Housing Enabler – an instrument for accessibility assessment of the physical housing. Tina Helle & Åse Brandt University of Lund, Health Sciences, Faculty of Medicine (SE) and University College Northern Jutland, Occupational Therapy department (DK...

  13. Fluorescent nanoparticles for intracellular sensing: A review

    Energy Technology Data Exchange (ETDEWEB)

    Ruedas-Rama, Maria J., E-mail: mjruedas@ugr.esmailto [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Walters, Jamie D. [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, UK CB2 1QT (United Kingdom); Orte, Angel [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Hall, Elizabeth A.H., E-mail: lisa.hall@biotech.cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT (United Kingdom)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. Black-Right-Pointing-Pointer Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. Black-Right-Pointing-Pointer Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

  14. Pilot project as enabler?

    DEFF Research Database (Denmark)

    Neisig, Margit; Glimø, Helle; Holm, Catrine Granzow

    This article deals with a systemic perspective on transition. The field of study addressed is a pilot project as enabler of transition in a highly complex polycentric context. From a Luhmannian systemic approach, a framework is created to understand and address barriers of change occurred using...

  15. BPR - Enabled Systems Engineering

    OpenAIRE

    Johnson, Leslie; Stergiou, Maria

    1999-01-01

    As traditional management techniques were no longer appropriate in the changing business environment, companies employed Business Process Reengineering (BPR) to achieve elevated business performance. Similarly, as traditional systems development approaches delivered disappointing results, system developers experimented with other models, including Evolutionary Delivery and Evolutionary Development, in order to enable successful technology exploitation by businesses. Both these business and sy...

  16. Enabling distributed collaborative science

    DEFF Research Database (Denmark)

    Hudson, T.; Sonnenwald, Diane H.; Maglaughlin, K.

    2000-01-01

    To enable collaboration over distance, a collaborative environment that uses a specialized scientific instrument called a nanoManipulator is evaluated. The nanoManipulator incorporates visualization and force feedback technology to allow scientists to see, feel, and modify biological samples being...

  17. Introduction to fluorescence microscopy.

    Science.gov (United States)

    Ghiran, Ionita C

    2011-01-01

    This chapter is an overview of basic principles of fluorescence microscopy, including a brief history on the invention of this type of microscopy. The chapter highlights important points related to properties of fluorochromes, resolution in fluorescence microscopy, phase contrast and fluorescence, fluorescence filters, construction of a fluorescence microscope, and tips on the correct use of this equipment.

  18. Fluorescence detection: SPIE volume 743

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, E.R.

    1987-01-01

    This book contains proceedings arranged into four sessions. They are: Fluorescence spectroscopic techniques; Fluorescence in analysis and materials characterization; Fluorescence in medicine and biochemistry; and Fluorescence in criminalistics.

  19. Spatially enabled land administration

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    enabling of land administration systems managing tenure, valuation, planning, and development will allow the information generated by these activities to be much more useful. Also, the services available to private and public sectors and to community organisations should commensurably improve. Knowledge....... In other words: Good governance and sustainable development is not attainable without sound land administration or - more broadly – sound land management. The paper presents a land management vision that incorporates the benefits of ICT enabled land administration functions. The idea is that spatial...... the communication between administrative systems and also establish more reliable data due to the use the original data instead of copies. In Denmark, such governmental guidelines for a service-oriented ITarchitecture in support of e-government are recently adopted. Finally, the paper presents the role of FIG...

  20. Enabling Wind Power Nationwide

    Energy Technology Data Exchange (ETDEWEB)

    Jose Zayas, Michael Derby, Patrick Gilman and Shreyas Ananthan,

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  1. EnableATIS strategy assessment.

    Science.gov (United States)

    2014-02-01

    Enabling Advanced Traveler Information Systems (EnableATIS) is the traveler information component of the Dynamic Mobility Application (DMA) program. The objective of : the EnableATIS effort is to foster transformative traveler information application...

  2. Controlled light-exposure microscopy reduces photobleaching and phototoxicity in fluorescence live-cell imaging.

    NARCIS (Netherlands)

    Hoebe, R.A.; van Oven, C.H.; Gadella, Th.W.J.; Dhonukshe, P.B.; van Noorden, C.J.F.; Manders, E.M.M.

    2007-01-01

    Fluorescence microscopy of living cells enables visualization of the dynamics and interactions of intracellular molecules. However, fluorescence live-cell imaging is limited by photobleaching and phototoxicity induced by the excitation light. Here we describe controlled light-exposure microscopy

  3. Controlled light-exposure microscopy reduces photobleaching and phototoxicity in fluorescence live-cell imaging

    NARCIS (Netherlands)

    Hoebe, R. A.; van Oven, C. H.; Gadella, T. W. J.; Dhonukshe, P. B.; van Noorden, C. J. F.; Manders, E. M. M.

    2007-01-01

    Fluorescence microscopy of living cells enables visualization of the dynamics and interactions of intracellular molecules. However, fluorescence live-cell imaging is limited by photobleaching and phototoxicity induced by the excitation light. Here we describe controlled light-exposure microscopy (

  4. The Structure of the Chromophore within a Red Fluorescent Protein from Zoanthus sp

    National Research Council Canada - National Science Library

    Martynov, Vladimir I

    2006-01-01

    ...: During the past decade, Green Fluorescent Protein (GFP) has become one of the most widely used fluorescent probes that enable direct visualization of the intracellular processes in the living cell...

  5. Enabling Digital Literacy

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Georgsen, Marianne

    2010-01-01

    There are some tensions between high-level policy definitions of “digital literacy” and actual teaching practice. We need to find workable definitions of digital literacy; obtain a better understanding of what digital literacy might look like in practice; and identify pedagogical approaches, which...... support teachers in designing digital literacy learning. We suggest that frameworks such as Problem Based Learning (PBL) are approaches that enable digital literacy learning because they provide good settings for engaging with digital literacy. We illustrate this through analysis of a case. Furthermore......, these operate on a meso-level mediating between high-level concepts of digital literacy and classroom practice....

  6. Fluorescence microscopy: A tool to study autophagy

    Science.gov (United States)

    Rai, Shashank; Manjithaya, Ravi

    2015-08-01

    Autophagy is a cellular recycling process through which a cell degrades old and damaged cellular components such as organelles and proteins and the degradation products are reused to provide energy and building blocks. Dysfunctional autophagy is reported in several pathological situations. Hence, autophagy plays an important role in both cellular homeostasis and diseased conditions. Autophagy can be studied through various techniques including fluorescence based microscopy. With the advancements of newer technologies in fluorescence microscopy, several novel processes of autophagy have been discovered which makes it an essential tool for autophagy research. Moreover, ability to tag fluorescent proteins with sub cellular targets has enabled us to evaluate autophagy processes in real time under fluorescent microscope. In this article, we demonstrate different aspects of autophagy in two different model organisms i.e. yeast and mammalian cells, with the help of fluorescence microscopy.

  7. Smart Grid Enabled EVSE

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-01-12

    The combined team of GE Global Research, Federal Express, National Renewable Energy Laboratory, and Consolidated Edison has successfully achieved the established goals contained within the Department of Energy’s Smart Grid Capable Electric Vehicle Supply Equipment funding opportunity. The final program product, shown charging two vehicles in Figure 1, reduces by nearly 50% the total installed system cost of the electric vehicle supply equipment (EVSE) as well as enabling a host of new Smart Grid enabled features. These include bi-directional communications, load control, utility message exchange and transaction management information. Using the new charging system, Utilities or energy service providers will now be able to monitor transportation related electrical loads on their distribution networks, send load control commands or preferences to individual systems, and then see measured responses. Installation owners will be able to authorize usage of the stations, monitor operations, and optimally control their electricity consumption. These features and cost reductions have been developed through a total system design solution.

  8. Laser Scanning Fluorescence Microscope

    Science.gov (United States)

    Hansen, Eric W.; Zelten, J. Peter; Wiseman, Benjamin A.

    1988-06-01

    We report on the development of a laser scanning fluorescence microscope possessing several features which facilitate its application to biological and biophysical analyses in living cells. It is built around a standard inverted microscope stand, enabling the use of standard optics, micromanipulation apparatus, and conventional (including video) microscopy in conjunction with laser scanning. The beam is scanned across the specimen by a pair of galvanometer-mounted mirrors, driven by a programmable controller which can operate in three modes: full raster scan, region of interest, and random-access. A full 512x512 pixel image can be acquired in one second. In region of interest mode, several subareas of the field can be selected for more rapid or detailed analysis. For those cases where the time scale of the observed phenomenon precludes full-field imaging, or where a full-field image is unnecessary, the random access mode enables an arbitrary pattern of isolated points to be selected and rapidly sequenced through. Via a graphical user interface implemented on the system's host computer, a user will be able to take a scout image either with video or a full-field laser scan, select regions or points on the scout image with a mouse, and set up experimental parameters such as detector integration times with a window-style menu. The instrument is designed to be a flexible testbed for investigating new techniques, without compromising its utility as a tool for biological research.

  9. Enabling graphene nanoelectronics.

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wei; Ohta, Taisuke; Biedermann, Laura Butler; Gutierrez, Carlos; Nolen, C. M.; Howell, Stephen Wayne; Beechem Iii, Thomas Edwin; McCarty, Kevin F.; Ross, Anthony Joseph, III

    2011-09-01

    Recent work has shown that graphene, a 2D electronic material amenable to the planar semiconductor fabrication processing, possesses tunable electronic material properties potentially far superior to metals and other standard semiconductors. Despite its phenomenal electronic properties, focused research is still required to develop techniques for depositing and synthesizing graphene over large areas, thereby enabling the reproducible mass-fabrication of graphene-based devices. To address these issues, we combined an array of growth approaches and characterization resources to investigate several innovative and synergistic approaches for the synthesis of high quality graphene films on technologically relevant substrate (SiC and metals). Our work focused on developing the fundamental scientific understanding necessary to generate large-area graphene films that exhibit highly uniform electronic properties and record carrier mobility, as well as developing techniques to transfer graphene onto other substrates.

  10. Nanotechnology-Enabled Optical Molecular Imaging of Breast Cancer

    Science.gov (United States)

    2013-09-01

    for breast cancer specimens that involve microcalcifications or nonpalpable masses and does not occur for palpable breast masses (Cabioglu et al...John V Frangioni. 2008. “Detection of Breast Cancer Microcalcifications Using a Dual-modality SPECT/NIR Fluorescent Probe.” Journal of the American...Enabled Optical Molecular Imaging of Breast Cancer PRINCIPAL INVESTIGATOR: Rebekah Drezek, Ph.D

  11. Enabling immersive simulation.

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Josh (University of California Santa Cruz, Santa Cruz, CA); Mateas, Michael (University of California Santa Cruz, Santa Cruz, CA); Hart, Derek H.; Whetzel, Jonathan; Basilico, Justin Derrick; Glickman, Matthew R.; Abbott, Robert G.

    2009-02-01

    The object of the 'Enabling Immersive Simulation for Complex Systems Analysis and Training' LDRD has been to research, design, and engineer a capability to develop simulations which (1) provide a rich, immersive interface for participation by real humans (exploiting existing high-performance game-engine technology wherever possible), and (2) can leverage Sandia's substantial investment in high-fidelity physical and cognitive models implemented in the Umbra simulation framework. We report here on these efforts. First, we describe the integration of Sandia's Umbra modular simulation framework with the open-source Delta3D game engine. Next, we report on Umbra's integration with Sandia's Cognitive Foundry, specifically to provide for learning behaviors for 'virtual teammates' directly from observed human behavior. Finally, we describe the integration of Delta3D with the ABL behavior engine, and report on research into establishing the theoretical framework that will be required to make use of tools like ABL to scale up to increasingly rich and realistic virtual characters.

  12. Reviews in fluorescence 2010

    CERN Document Server

    Geddes, Chris D

    2011-01-01

    ""Reviews in Fluorescence 2010"", the seventh volume of the book serial from Springer, serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence and closely related disciplines. It summarizes the year's progress in fluorescence and its applications, with authoritative analytical reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. ""Reviews in Fluorescence"" offers an essential reference material for any lab working in the fluoresc

  13. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  14. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements

    Science.gov (United States)

    George Abraham, Bobin; Sarkisyan, Karen S.; Mishin, Alexander S.; Santala, Ville; Tkachenko, Nikolai V.; Karp, Matti

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM). PMID:26237400

  15. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements.

    Directory of Open Access Journals (Sweden)

    Bobin George Abraham

    Full Text Available Fluorescence Resonance Energy Transfer (FRET using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM.

  16. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements.

    Science.gov (United States)

    George Abraham, Bobin; Sarkisyan, Karen S; Mishin, Alexander S; Santala, Ville; Tkachenko, Nikolai V; Karp, Matti

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM).

  17. Peptide-stabilized, fluorescent silver nanoclusters

    DEFF Research Database (Denmark)

    Gregersen, Simon; Vosch, Tom André Jos; Jensen, Knud Jørgen

    2016-01-01

    on a hydroxymethyl-benzoic acid (HMBA) polyethylene glycol polyacrylamide copolymer (PEGA) resin enabled on-resin screening and evaluation of a peptide library, leading to identification of novel peptide-stabilized, fluorescent AgNCs. Using systematic amino acid substitutions, we synthesized and screened a 144...

  18. Fluorescein Derivatives in Intravital Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Michael S. Roberts

    2013-08-01

    Full Text Available Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples.

  19. Novel disposable biochip platform employing supercritical angle fluorescence for enhanced fluorescence collection.

    Science.gov (United States)

    Hill, Duncan; McDonnell, Barry; Hearty, Stephen; Basabe-Desmonts, Lourdes; Blue, Robert; Trnavsky, Michal; McAtamney, Colm; O'Kennedy, Richard; MacCraith, Brian D

    2011-08-01

    This paper presents an overview of development of a novel disposable plastic biochip for multiplexed clinical diagnostic applications. The disposable biochip is manufactured using a low-cost, rapid turn- around injection moulding process and consists of nine parabolic elements on a planar substrate. The optical elements are based on supercritical angle fluorescence (SAF) which provides substantial enhancement of the fluorescence collection efficiency but also confines the fluorescence detection volume strictly to the immediate proximity of the biochip surface, thereby having the potential to discriminate against background fluorescence from the analyte solution. An optical reader is also described that enables interrogation and fluorescence collection from the nine optical elements on the chip. The sensitivity of the system was determined with a biotin-avidin assay while its clinical utility was demonstrated in an assay for C-reactive protein (CRP), an inflammation marker.

  20. DNA nanotechnology and fluorescence applications.

    Science.gov (United States)

    Schlichthaerle, Thomas; Strauss, Maximilian T; Schueder, Florian; Woehrstein, Johannes B; Jungmann, Ralf

    2016-06-01

    Structural DNA nanotechnology allow researchers to use the unique molecular recognition properties of DNA strands to construct nanoscale objects with almost arbitrary complexity in two and three dimensions. Abstracted as molecular breadboards, DNA nanostructures enable nanometer-precise placement of guest molecules such as proteins, fluorophores, or nanoparticles. These assemblies can be used to study biological phenomena with unprecedented control over number, spacing, and molecular identity. Here, we give a general introduction to structural DNA nanotechnology and more specifically discuss applications of DNA nanostructures in the field of fluorescence and plasmonics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. FOILFEST :community enabled security.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Judy Hennessey; Johnson, Curtis Martin; Whitley, John B.; Drayer, Darryl Donald; Cummings, John C., Jr. (.,; .)

    2005-09-01

    The Advanced Concepts Group of Sandia National Laboratories hosted a workshop, ''FOILFest: Community Enabled Security'', on July 18-21, 2005, in Albuquerque, NM. This was a far-reaching look into the future of physical protection consisting of a series of structured brainstorming sessions focused on preventing and foiling attacks on public places and soft targets such as airports, shopping malls, hotels, and public events. These facilities are difficult to protect using traditional security devices since they could easily be pushed out of business through the addition of arduous and expensive security measures. The idea behind this Fest was to explore how the public, which is vital to the function of these institutions, can be leveraged as part of a physical protection system. The workshop considered procedures, space design, and approaches for building community through technology. The workshop explored ways to make the ''good guys'' in public places feel safe and be vigilant while making potential perpetrators of harm feel exposed and convinced that they will not succeed. Participants in the Fest included operators of public places, social scientists, technology experts, representatives of government agencies including DHS and the intelligence community, writers and media experts. Many innovative ideas were explored during the fest with most of the time spent on airports, including consideration of the local airport, the Albuquerque Sunport. Some provocative ideas included: (1) sniffers installed in passage areas like revolving door, escalators, (2) a ''jumbotron'' showing current camera shots in the public space, (3) transparent portal screeners allowing viewing of the screening, (4) a layered open/funnel/open/funnel design where open spaces are used to encourage a sense of ''communitas'' and take advantage of citizen ''sensing'' and funnels are technological

  2. Characterization of flavin-based fluorescent proteins: an emerging class of fluorescent reporters.

    Science.gov (United States)

    Mukherjee, Arnab; Walker, Joshua; Weyant, Kevin B; Schroeder, Charles M

    2013-01-01

    Fluorescent reporter proteins based on flavin-binding photosensors were recently developed as a new class of genetically encoded probes characterized by small size and oxygen-independent maturation of fluorescence. Flavin-based fluorescent proteins (FbFPs) address two major limitations associated with existing fluorescent reporters derived from the green fluorescent protein (GFP)-namely, the overall large size and oxygen-dependent maturation of fluorescence of GFP. However, FbFPs are at a nascent stage of development and have been utilized in only a handful of biological studies. Importantly, a full understanding of the performance and properties of FbFPs as a practical set of biological probes is lacking. In this work, we extensively characterize three FbFPs isolated from Pseudomonas putida, Bacillus subtilis, and Arabidopsis thaliana, using in vitro studies to assess probe brightness, oligomeric state, maturation time, fraction of fluorescent holoprotein, pH tolerance, redox sensitivity, and thermal stability. Furthermore, we validate FbFPs as stable molecular tags using in vivo studies by constructing a series of FbFP-based transcriptional constructs to probe promoter activity in Escherichia coli. Overall, FbFPs show key advantages as broad-spectrum biological reporters including robust pH tolerance (4-11), thermal stability (up to 60°C), and rapid maturation of fluorescence (fluorescence and slow kinetics of fluorescence maturation (10-40 minutes for half maximal fluorescence recovery). From this view, FbFPs represent a useful new addition to the fluorescent reporter protein palette, and our results constitute an important framework to enable researchers to implement and further engineer improved FbFP-based reporters with enhanced brightness and tighter flavin binding, which will maximize their potential benefits.

  3. Fluorescent Lamp Replacement Study

    Science.gov (United States)

    2017-07-01

    C -1 D FLUORESCENT LAMP SPECIFICATION SHEETS . . . . . . . . . . . . . . . . . . . . . . . . . . D -1 E LED WAVES’ LED ...friendly products, advances in efficiency, and lower production costs for lamps . The conversion of fluorescent bulbs to LED technology has many benefits...repeatedly turned on and off. (5) LEDs can be used in existing fluorescent lighting fixtures using LED retrofit kits or replacement lamps . (6

  4. Mercury dosing solutions for fluorescent lamps

    Science.gov (United States)

    Corazza, A.; Boffito, C.

    2008-07-01

    A review of the different technologies used to dose mercury in fluorescent lamps is presented. Conventional liquid mercury dosing is gradually being replaced with more reliable and environmentally friendly solutions that enable a significant reduction of the amount of mercury introduced in the lamp, so as to cope with more stringent regulations issued to minimize the environmental impact of exhausted lamps. This paper will review the most advanced novel methods to assure an accurate and fine dosing of mercury in fluorescent lamps, especially focusing on solutions based on the use of solid alloys.

  5. Mercury dosing solutions for fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, A; Boffito, C [SAES Getters S.p.A., Viale Italia 77, Lainate (MI) 20020 (Italy)], E-mail: alessio_corazza@saes-group.com

    2008-07-21

    A review of the different technologies used to dose mercury in fluorescent lamps is presented. Conventional liquid mercury dosing is gradually being replaced with more reliable and environmentally friendly solutions that enable a significant reduction of the amount of mercury introduced in the lamp, so as to cope with more stringent regulations issued to minimize the environmental impact of exhausted lamps. This paper will review the most advanced novel methods to assure an accurate and fine dosing of mercury in fluorescent lamps, especially focusing on solutions based on the use of solid alloys.

  6. Geo-Enabled, Mobile Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard

    2006-01-01

    We are witnessing the emergence of a global infrastructure that enables the widespread deployment of geo-enabled, mobile services in practice. At the same time, the research community has also paid increasing attention to data management aspects of mobile services. This paper offers me...

  7. Toward genome-enabled mycology.

    Science.gov (United States)

    Hibbett, David S; Stajich, Jason E; Spatafora, Joseph W

    2013-01-01

    Genome-enabled mycology is a rapidly expanding field that is characterized by the pervasive use of genome-scale data and associated computational tools in all aspects of fungal biology. Genome-enabled mycology is integrative and often requires teams of researchers with diverse skills in organismal mycology, bioinformatics and molecular biology. This issue of Mycologia presents the first complete fungal genomes in the history of the journal, reflecting the ongoing transformation of mycology into a genome-enabled science. Here, we consider the prospects for genome-enabled mycology and the technical and social challenges that will need to be overcome to grow the database of complete fungal genomes and enable all fungal biologists to make use of the new data.

  8. Fluorescence Live Cell Imaging

    OpenAIRE

    Ettinger, Andreas; Wittmann, Torsten

    2014-01-01

    Fluorescence microscopy of live cells has become an integral part of modern cell biology. Fluorescent protein (FP) tags, live cell dyes, and other methods to fluorescently label proteins of interest provide a range of tools to investigate virtually any cellular process under the microscope. The two main experimental challenges in collecting meaningful live cell microscopy data are to minimize photodamage while retaining a useful signal-to-noise ratio and to provide a suitable environment for ...

  9. Maximizing the biochemical resolving power of fluorescence microscopy.

    Science.gov (United States)

    Esposito, Alessandro; Popleteeva, Marina; Venkitaraman, Ashok R

    2013-01-01

    Most recent advances in fluorescence microscopy have focused on achieving spatial resolutions below the diffraction limit. However, the inherent capability of fluorescence microscopy to non-invasively resolve different biochemical or physical environments in biological samples has not yet been formally described, because an adequate and general theoretical framework is lacking. Here, we develop a mathematical characterization of the biochemical resolution in fluorescence detection with Fisher information analysis. To improve the precision and the resolution of quantitative imaging methods, we demonstrate strategies for the optimization of fluorescence lifetime, fluorescence anisotropy and hyperspectral detection, as well as different multi-dimensional techniques. We describe optimized imaging protocols, provide optimization algorithms and describe precision and resolving power in biochemical imaging thanks to the analysis of the general properties of Fisher information in fluorescence detection. These strategies enable the optimal use of the information content available within the limited photon-budget typically available in fluorescence microscopy. This theoretical foundation leads to a generalized strategy for the optimization of multi-dimensional optical detection, and demonstrates how the parallel detection of all properties of fluorescence can maximize the biochemical resolving power of fluorescence microscopy, an approach we term Hyper Dimensional Imaging Microscopy (HDIM). Our work provides a theoretical framework for the description of the biochemical resolution in fluorescence microscopy, irrespective of spatial resolution, and for the development of a new class of microscopes that exploit multi-parametric detection systems.

  10. Photobleaching correction in fluorescence microscopy images

    Energy Technology Data Exchange (ETDEWEB)

    Vicente, Nathalie B; Diaz Zamboni, Javier E; Adur, Javier F; Paravani, Enrique V; Casco, Victor H [Microscopy Laboratory, School of Engineering - Bioengineering, National University of Entre Rios (UNER), Ruta 11, Km 10 (3101), Oro Verde, Entre Rios (Argentina)

    2007-11-15

    Fluorophores are used to detect molecular expression by highly specific antigen-antibody reactions in fluorescence microscopy techniques. A portion of the fluorophore emits fluorescence when irradiated with electromagnetic waves of particular wavelengths, enabling its detection. Photobleaching irreversibly destroys fluorophores stimulated by radiation within the excitation spectrum, thus eliminating potentially useful information. Since this process may not be completely prevented, techniques have been developed to slow it down or to correct resulting alterations (mainly, the decrease in fluorescent signal). In the present work, the correction by photobleaching curve was studied using E-cadherin (a cell-cell adhesion molecule) expression in Bufo arenarum embryos. Significant improvements were observed when applying this simple, inexpensive and fast technique.

  11. Taxonomy Enabled Discovery (TED) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposal addresses the NASA's need to enable scientific discovery and the topic's requirements for: processing large volumes of data, commonly available on the...

  12. Computer Security Systems Enable Access.

    Science.gov (United States)

    Riggen, Gary

    1989-01-01

    A good security system enables access and protects information from damage or tampering, but the most important aspects of a security system aren't technical. A security procedures manual addresses the human element of computer security. (MLW)

  13. Secure Enclaves-Enabled Technologies

    Science.gov (United States)

    2014-04-25

    William Vine , Benjamin Vowell Team Advisor: Capt Nick Mastronardi UNITED STATES AIR FORCE ACADEMY Introduction Secure Enclaves-Enabled...hardware solution to cyber security is unique in an industry dominated by software solutions which hackers inevitably find ways to circumnavigate

  14. Experiments with Fluorescent Lamps

    Science.gov (United States)

    Kraftmakher, Yaakov

    2010-10-01

    The experiments described below show the irradiance and illuminance spectra of two fluorescent lamps in relation to their color temperatures, and the efficacy in comparison to that of an incandescent lamp. Spectra of "warm white" and "cool daylight" fluorescent lamps are demonstrated.

  15. LEDs for fluorescence microscopy

    NARCIS (Netherlands)

    Young, I.T.; Garini, Y.; Dietrich, H.R.C.; Van Oel, W.; Liqui Lung, G.

    2004-01-01

    Traditional light sources for fluorescence microscopy have been mercury lamps, xenon lamps, and lasers. These sources have been essential in the development of fluorescence microscopy but each can have serious disadvantages: lack of near monochromaticity, heat generation, cost, lifetime of the light

  16. Membranes and Fluorescence microscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2009-01-01

    Fluorescence spectroscopy-based techniques using conventional fluorimeters have been extensively applied since the late 1960s to study different aspects of membrane-related phenomena, i.e., mainly relating to lipid-lipid and lipid-protein (peptide) interactions. Even though fluorescence...

  17. Diversity and Evolution of Coral Fluorescent Proteins

    Science.gov (United States)

    Alieva, Naila O.; Konzen, Karen A.; Field, Steven F.; Meleshkevitch, Ella A.; Hunt, Marguerite E.; Beltran-Ramirez, Victor; Miller, David J.; Wiedenmann, Jörg; Salih, Anya; Matz, Mikhail V.

    2008-01-01

    GFP-like fluorescent proteins (FPs) are the key color determinants in reef-building corals (class Anthozoa, order Scleractinia) and are of considerable interest as potential genetically encoded fluorescent labels. Here we report 40 additional members of the GFP family from corals. There are three major paralogous lineages of coral FPs. One of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full complement of typical coral fluorescent colors (cyan, green, and red) and underwent sorting between coral groups. Among the newly cloned proteins are a “chromo-red” color type from Echinopora forskaliana (family Faviidae) and pink chromoprotein from Stylophora pistillata (Pocilloporidae), both evolving independently from the rest of coral chromoproteins. There are several cyan FPs that possess a novel kind of excitation spectrum indicating a neutral chromophore ground state, for which the residue E167 is responsible (numeration according to GFP from A. victoria). The chromoprotein from Acropora millepora is an unusual blue instead of purple, which is due to two mutations: S64C and S183T. We applied a novel probabilistic sampling approach to recreate the common ancestor of all coral FPs as well as the more derived common ancestor of three main fluorescent colors of the Faviina suborder. Both proteins were green such as found elsewhere outside class Anthozoa. Interestingly, a substantial fraction of the all-coral ancestral protein had a chromohore apparently locked in a non-fluorescent neutral state, which may reflect the transitional stage that enabled rapid color diversification early in the history of coral FPs. Our results highlight the extent of convergent or parallel evolution of the color diversity in corals, provide the foundation for experimental studies of evolutionary processes that led to color diversification, and enable a comparative analysis of structural

  18. Diversity and evolution of coral fluorescent proteins.

    Directory of Open Access Journals (Sweden)

    Naila O Alieva

    2008-07-01

    Full Text Available GFP-like fluorescent proteins (FPs are the key color determinants in reef-building corals (class Anthozoa, order Scleractinia and are of considerable interest as potential genetically encoded fluorescent labels. Here we report 40 additional members of the GFP family from corals. There are three major paralogous lineages of coral FPs. One of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full complement of typical coral fluorescent colors (cyan, green, and red and underwent sorting between coral groups. Among the newly cloned proteins are a "chromo-red" color type from Echinopora forskaliana (family Faviidae and pink chromoprotein from Stylophora pistillata (Pocilloporidae, both evolving independently from the rest of coral chromoproteins. There are several cyan FPs that possess a novel kind of excitation spectrum indicating a neutral chromophore ground state, for which the residue E167 is responsible (numeration according to GFP from A. victoria. The chromoprotein from Acropora millepora is an unusual blue instead of purple, which is due to two mutations: S64C and S183T. We applied a novel probabilistic sampling approach to recreate the common ancestor of all coral FPs as well as the more derived common ancestor of three main fluorescent colors of the Faviina suborder. Both proteins were green such as found elsewhere outside class Anthozoa. Interestingly, a substantial fraction of the all-coral ancestral protein had a chromohore apparently locked in a non-fluorescent neutral state, which may reflect the transitional stage that enabled rapid color diversification early in the history of coral FPs. Our results highlight the extent of convergent or parallel evolution of the color diversity in corals, provide the foundation for experimental studies of evolutionary processes that led to color diversification, and enable a comparative analysis of

  19. Dynamic fluorescence imaging with molecular agents for cancer detection

    Science.gov (United States)

    Kwon, Sun Kuk

    Non-invasive dynamic optical imaging of small animals requires the development of a novel fluorescence imaging modality. Herein, fluorescence imaging is demonstrated with sub-second camera integration times using agents specifically targeted to disease markers, enabling rapid detection of cancerous regions. The continuous-wave fluorescence imaging acquires data with an intensified or an electron-multiplying charge-coupled device. The work presented in this dissertation (i) assessed dose-dependent uptake using dynamic fluorescence imaging and pharmacokinetic (PK) models, (ii) evaluated disease marker availability in two different xenograft tumors, (iii) compared the impact of autofluorescence in fluorescence imaging of near-infrared (NIR) vs. red light excitable fluorescent contrast agents, (iv) demonstrated dual-wavelength fluorescence imaging of angiogenic vessels and lymphatics associated with a xenograft tumor model, and (v) examined dynamic multi-wavelength, whole-body fluorescence imaging with two different fluorescent contrast agents. PK analysis showed that the uptake of Cy5.5-c(KRGDf) in xenograft tumor regions linearly increased with doses of Cy5.5-c(KRGDf) up to 1.5 nmol/mouse. Above 1.5 nmol/mouse, the uptake did not increase with doses, suggesting receptor saturation. Target to background ratio (TBR) and PK analysis for two different tumor cell lines showed that while Kaposi's sarcoma (KS1767) exhibited early and rapid uptake of Cy5.5-c(KRGDf), human melanoma tumors (M21) had non-significant TBR differences and early uptake rates similar to the contralateral normal tissue regions. The differences may be due to different compartment location of the target. A comparison of fluorescence imaging with NIR vs. red light excitable fluorescent dyes demonstrates that NIR dyes are associated with less background signal, enabling rapid tumor detection. In contrast, animals injected with red light excitable fluorescent dyes showed high autofluorescence. Dual

  20. Multicolor, Fluorescent Supercapacitor Fiber.

    Science.gov (United States)

    Liao, Meng; Sun, Hao; Zhang, Jing; Wu, Jingxia; Xie, Songlin; Fu, Xuemei; Sun, Xuemei; Wang, Bingjie; Peng, Huisheng

    2017-10-05

    Fiber-shaped supercapacitors have attracted broad attentions from both academic and industrial communities due to the demonstrated potentials as next-generation power modules. However, it is important while remains challenging to develop dark-environment identifiable supercapacitor fibers for enhancement on operation convenience and security in nighttime applications. Herein, a novel family of colorful fluorescent supercapacitor fibers has been produced from aligned multi-walled carbon nanotube sheets. Fluorescent dye particles are introduced and stably anchored on the surfaces of aligned multi-walled carbon nanotubes to prepare hybrid fiber electrodes with a broad range of colors from red to purple. The fluorescent component in the dye introduces fluorescent indication capability to the fiber, which is particularly promising for flexible and wearable devices applied in dark environment. In addition, the colorful fluorescent supercapacitor fibers also maintain high electrochemical performance under cyclic bending and charge-discharge processes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Fluorescence and Spectral Imaging

    Directory of Open Access Journals (Sweden)

    Ralph S. DaCosta

    2007-01-01

    Full Text Available Early identification of dysplasia remains a critical goal for diagnostic endoscopy since early discovery directly improves patient survival because it allows endoscopic or surgical intervention with disease localized without lymph node involvement. Clinical studies have successfully used tissue autofluorescence with conventional white light endoscopy and biopsy for detecting adenomatous colonic polyps, differentiating benign hyperplastic from adenomas with acceptable sensitivity and specificity. In Barrett's esophagus, the detection of dysplasia remains problematic because of background inflammation, whereas in the squamous esophagus, autofluorescence imaging appears to be more dependable. Point fluorescence spectroscopy, although playing a crucial role in the pioneering mechanistic development of fluorescence endoscopic imaging, does not seem to have a current function in endoscopy because of its nontargeted sampling and suboptimal sensitivity and specificity. Other point spectroscopic modalities, such as Raman spectroscopy and elastic light scattering, continue to be evaluated in clinical studies, but still suffer the significant disadvantages of being random and nonimaging. A recent addition to the fluorescence endoscopic imaging arsenal is the use of confocal fluorescence endomicroscopy, which provides real-time optical biopsy for the first time. To improve detection of dysplasia in the gastrointestinal tract, a new and exciting development has been the use of exogenous fluorescence contrast probes that specifically target a variety of disease-related cellular biomarkers using conventional fluorescent dyes and novel potent fluorescent nanocrystals (i.e., quantum dots. This is an area of great promise, but still in its infancy, and preclinical studies are currently under way.

  2. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM; Waldo, Geoffrey S [Santa Fe, NM; Kiss, Csaba [Los Alamos, NM

    2012-05-01

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  3. Fluorescent discharge lamp

    Science.gov (United States)

    Mukai, E.; Otsuka, H.; Nomi, K.; Honmo, I.

    1982-01-01

    A rapidly illuminating fluorescent lamp 1,200 mm long and 32.5 mm in diameter with an interior conducting strip which is compatible with conventional fixtures and ballasts is described. The fluorescent lamp is composed of a linear glass tube, electrodes sealed at both ends, mercury and raregas sealed in the glass tube, a fluorescent substance clad on the inner walls of the glass tube, and a clad conducting strip extending the entire length of the glass tube in the axial direction on the inner surface of the tube.

  4. Fluorescent discharge lamp

    Science.gov (United States)

    Mukai, E.; Otsuka, H.; Nomi, K.; Honmo, I.

    1982-07-01

    A rapidly illuminating fluorescent lamp 1,200 mm long and 32.5 mm in diameter with an interior conducting strip which is compatible with conventional fixtures and ballasts is described. The fluorescent lamp is composed of a linear glass tube, electrodes sealed at both ends, mercury and raregas sealed in the glass tube, a fluorescent substance clad on the inner walls of the glass tube, and a clad conducting strip extending the entire length of the glass tube in the axial direction on the inner surface of the tube.

  5. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM; Waldo, Geoffrey S [Santa Fe, NM; Kiss, Csaba [Los Alamos, NM

    2011-03-22

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  6. Nonlinear light-sheet fluorescence microscopy by photobleaching imprinting.

    Science.gov (United States)

    Gao, Liang; Zhu, Liren; Li, Chiye; Wang, Lihong V

    2014-04-06

    We present a nonlinear light-sheet fluorescence microscopy (LSFM) scheme based on photobleaching imprinting. By measuring photobleaching-induced fluorescence decay, our method simultaneously achieves a large imaging field of view and a thin optical section. Furthermore, the scattered-light-induced background is significantly reduced, considerably improving image contrast. Our method is expected to expand the application field of LSFM into the optical quasi-ballistic regime, enabling studies on non-transparent biological samples.

  7. Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications

    OpenAIRE

    Corr, S A; Rakovich, Y.P.; Gun'ko, Y.K.

    2008-01-01

    AbstractNanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional...

  8. Resonance Fluorescence from an Artificial Atom in Squeezed Vacuum

    Directory of Open Access Journals (Sweden)

    D. M. Toyli

    2016-07-01

    Full Text Available We present an experimental realization of resonance fluorescence in squeezed vacuum. We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier. We investigate the fluorescence spectra in the weak and strong driving regimes, observing up to 3.1 dB of reduction of the fluorescence linewidth below the ordinary vacuum level and a dramatic dependence of the Mollow triplet spectrum on the relative phase of the driving and squeezed vacuum fields. Our results are in excellent agreement with predictions for spectra produced by a two-level atom in squeezed vacuum [Phys. Rev. Lett. 58, 2539 (1987], demonstrating that resonance fluorescence offers a resource-efficient means to characterize squeezing in cryogenic environments.

  9. Fluorescent radiation converter

    Science.gov (United States)

    Viehmann, W. (Inventor)

    1981-01-01

    A fluorescence radiation converter is described which includes a substantially undoped optically transparent substrate and a waveshifter coating deposited on at least one portion of the substrate for absorption of radiation and conversion of fluorescent radiation. The coating is formed to substantially 1000 g/liter of a solvent, 70 to 200 g/liter of an organic polymer, and 0.2 to 25 g/liter of at least one organic fluorescent dye. The incoming incident radiation impinges on the coating. Radiation is absorbed by the fluorescent dye and is re-emitted as a longer wavelength radiation. Radiation is trapped within the substrate and is totally internally reflected by the boundary surface. Emitted radiation leaves the substrate ends to be detected.

  10. Fluorescent filtered electrophosphorescence

    Science.gov (United States)

    Forrest, Stephen R [Princeton, NJ; Sun, Yiru [Princeton, NJ; Giebink, Noel [Princeton, NJ; Thompson, Mark E [Anaheim Hills, CA

    2009-01-06

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.

  11. Introduction to fluorescence

    CERN Document Server

    Jameson, David M

    2014-01-01

    "An essential contribution to educating scientists in the principles of fluorescence. It will also be an important addition to the libraries of practitioners applying the principles of molecular fluorescence."-Ken Jacobson, Kenan Distinguished Professor of Cell Biology and Physiology, University of North Carolina at Chapel Hill"An exquisite compendium of fluorescence and its applications in biochemistry enriched by a very exciting historical perspective. This book will become a standard text for graduate students and other scientists."-Drs. Zygmunt (Karol) Gryczynski and Ignacy Gryczynski, University of North Texas Health Science Center"… truly a masterwork, combining clarity, precision, and good humor. The reader, novice or expert, will be pleased with the text and will not stop reading. It is a formidable account of the fluorescence field, which has impacted the life sciences so considerably in the last 60 years."-Jerson L. Silva, M.D., Ph.D., Professor and Director, National Institute of Science and Tech...

  12. Smart Grid enabled heat pumps

    DEFF Research Database (Denmark)

    Carmo, Carolina; Detlefsen, Nina; Nielsen, Mads Pagh

    2014-01-01

    The transition towards a 100 % fossil-free energy system, while achieving extreme penetration levels of intermittent wind and solar power in electricity generation, requires demand-side technologies that are smart (intermittency-friendly) and efficient. The integration of Smart Grid enabling...

  13. Editorial: Schools as enabling environments

    African Journals Online (AJOL)

    Hennie

    South African Journal of Education, Volume 34, Number 4, November 2014. 1. Editorial, 6 pages, http://www.sajournalofeducation.co.za. Editorial: Schools as enabling environments. Guest Editors: Mahlapahlapana Themane and David Osher. Children and youth need safe and supportive schools if they are to succeed in ...

  14. Fluorescence (Multiwave) Confocal Microscopy.

    Science.gov (United States)

    Welzel, J; Kästle, Raphaela; Sattler, Elke C

    2016-10-01

    In addition to reflectance confocal microscopy, multiwave confocal microscopes with different laser wavelengths in combination with exogenous fluorophores allow fluorescence mode confocal microscopy in vivo and ex vivo. Fluorescence mode confocal microscopy improves the contrast between the epithelium and the surrounding soft tissue and allows the depiction of certain structures, like epithelial tumors, nerves, and glands. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Advances in fluorescence labeling strategies for dynamic cellular imaging.

    Science.gov (United States)

    Dean, Kevin M; Palmer, Amy E

    2014-07-01

    Synergistic advances in optical physics, probe design, molecular biology, labeling techniques and computational analysis have propelled fluorescence imaging into new realms of spatiotemporal resolution and sensitivity. This review aims to discuss advances in fluorescent probes and live-cell labeling strategies, two areas that remain pivotal for future advances in imaging technology. Fluorescent protein- and bio-orthogonal-based methods for protein and RNA imaging are discussed as well as emerging bioengineering techniques that enable their expression at specific genomic loci (for example, CRISPR and TALENs). Important attributes that contribute to the success of each technique are emphasized, providing a guideline for future advances in dynamic live-cell imaging.

  16. Tracking Lithium Ions via Widefield Fluorescence Microscopy for Battery Diagnostics.

    Science.gov (United States)

    Padilla, Nicolas A; Rea, Morgan T; Foy, Michael; Upadhyay, Sunil P; Desrochers, Kyle A; Derus, Tyler; Knapper, Kassandra A; Hunter, Nathanael H; Wood, Sharla; Hinton, Daniel A; Cavell, Andrew C; Masias, Alvaro G; Goldsmith, Randall H

    2017-07-28

    Direct tracking of lithium ions with time and spatial resolution can provide an important diagnostic tool for understanding mechanisms in lithium ion batteries. A fluorescent indicator of lithium ions, 2-(2-hydroxyphenyl)naphthoxazole, was synthesized and used for real-time tracking of lithium ions via widefield fluorescence microscopy. The fluorophore can be excited with visible light and was shown to enable quantitative determination of the lithium ion diffusion constant in a microfluidic model system for a plasticized polymer electrolyte lithium battery. The use of widefield fluorescence microscopy for in situ tracking of lithium ions in batteries is discussed.

  17. Characterization of flavin-based fluorescent proteins: an emerging class of fluorescent reporters.

    Directory of Open Access Journals (Sweden)

    Arnab Mukherjee

    Full Text Available Fluorescent reporter proteins based on flavin-binding photosensors were recently developed as a new class of genetically encoded probes characterized by small size and oxygen-independent maturation of fluorescence. Flavin-based fluorescent proteins (FbFPs address two major limitations associated with existing fluorescent reporters derived from the green fluorescent protein (GFP-namely, the overall large size and oxygen-dependent maturation of fluorescence of GFP. However, FbFPs are at a nascent stage of development and have been utilized in only a handful of biological studies. Importantly, a full understanding of the performance and properties of FbFPs as a practical set of biological probes is lacking. In this work, we extensively characterize three FbFPs isolated from Pseudomonas putida, Bacillus subtilis, and Arabidopsis thaliana, using in vitro studies to assess probe brightness, oligomeric state, maturation time, fraction of fluorescent holoprotein, pH tolerance, redox sensitivity, and thermal stability. Furthermore, we validate FbFPs as stable molecular tags using in vivo studies by constructing a series of FbFP-based transcriptional constructs to probe promoter activity in Escherichia coli. Overall, FbFPs show key advantages as broad-spectrum biological reporters including robust pH tolerance (4-11, thermal stability (up to 60°C, and rapid maturation of fluorescence (<3 min.. In addition, the FbFP derived from Arabidopsis thaliana (iLOV emerged as a stable and nonperturbative reporter of promoter activity in Escherichia coli. Our results demonstrate that FbFP-based reporters have the potential to address key limitations associated with the use of GFP, such as pH-sensitive fluorescence and slow kinetics of fluorescence maturation (10-40 minutes for half maximal fluorescence recovery. From this view, FbFPs represent a useful new addition to the fluorescent reporter protein palette, and our results constitute an important framework to

  18. Fluorescence-based biosensors.

    Science.gov (United States)

    Strianese, Maria; Staiano, Maria; Ruggiero, Giuseppe; Labella, Tullio; Pellecchia, Claudio; D'Auria, Sabato

    2012-01-01

    The field of optical sensors has been a growing research area over the last three decades. A wide range of books and review articles has been published by experts in the field who have highlighted the advantages of optical sensing over other transduction methods. Fluorescence is by far the method most often applied and comes in a variety of schemes. Nowadays, one of the most common approaches in the field of optical biosensors is to combine the high sensitivity of fluorescence detection in combination with the high selectivity provided by ligand-binding proteins. In this chapter we deal with reviewing our recent results on the implementation of fluorescence-based sensors for monitoring environmentally hazardous gas molecules (e.g. nitric oxide, hydrogen sulfide). Reflectivity-based sensors, fluorescence correlation spectroscopy-based (FCS) systems, and sensors relying on the enhanced fluorescence emission on silver island films (SIFs) coupled to the total internal reflection fluorescence mode (TIRF) for the detection of gliadin and other prolamines considered toxic for celiac patients are also discussed herein.

  19. Simultaneous single molecule atomic force and fluorescence lifetime imaging

    Science.gov (United States)

    Schulz, Olaf; Koberling, Felix; Walters, Deron; Koenig, Marcelle; Viani, Jacob; Ros, Robert

    2010-02-01

    The combination of atomic force microscopy (AFM) with single-molecule-sensitive confocal fluorescence microscopy enables a fascinating investigation into the structure, dynamics and interactions of single biomolecules or their assemblies. AFM reveals the structure of macromolecular complexes with nanometer resolution, while fluorescence can facilitate the identification of their constituent parts. In addition, nanophotonic effects, such as fluorescence quenching or enhancement due to the AFM tip, can be used to increase the optical resolution beyond the diffraction limit, thus enabling the identification of different fluorescence labels within a macromolecular complex. We present a novel setup consisting of two commercial, state-of-the-art microscopes. A sample scanning atomic force microscope is mounted onto an objective scanning confocal fluorescence lifetime microscope. The ability to move the sample and objective independently allows for precise alignment of AFM probe and laser focus with an accuracy down to a few nanometers. Time correlated single photon counting (TCSPC) gives us the opportunity to measure single-molecule fluorescence lifetimes. We will be able to study molecular complexes in the vicinity of an AFM probe on a level that has yet to be achieved. With this setup we simultaneously obtained single molecule sensitivity in the AFM topography and fluorescence lifetime imaging of YOYO-1 stained lambda-DNA samples and we showed silicon tip induced single molecule quenching on organic fluorophores.

  20. Fluorescence imaging of dendritic spines of Golgi-Cox-stained neurons using brightening background

    Science.gov (United States)

    Ai, Min; Xiong, Hanqing; Yang, Tao; Shang, Zhenhua; Chen, Muqing; Liu, Xiuli; Zeng, Shaoqun

    2015-01-01

    We report a novel fluorescence imaging approach to imaging nonfluorescence-labeled biological tissue samples. The method was demonstrated by imaging neurons in Golgi-Cox-stained and epoxy-resin-embedded samples through the excitation of the background fluorescence of the specimens. The dark neurons stood out clearly against background fluorescence in the images, enabling the tracing of a single dendritic spine using both confocal and wide-field fluorescence microscopy. The results suggest that the reported fluorescence imaging method would provide an effective alternative solution to image nonfluorescence-labeled samples, and it allows tracing the dendritic spine structure of neurons.

  1. Circular dichroism spectroscopy of fluorescent proteins

    NARCIS (Netherlands)

    Visser, N.V.; Hink, M.A.; Borst, J.W.; Krogt, van der G.N.M.; Visser, A.J.W.G.

    2002-01-01

    Circular dichroism (CD) spectra have been obtained from several variants of green fluorescent protein: blue fluorescent protein (BFP), enhanced cyan fluorescent protein (CFP), enhanced green fluorescent protein (GFP), enhanced yellow fluorescent protein (YFP), all from Aequorea victoria, and the red

  2. Organizational Enablers for Project Governance

    DEFF Research Database (Denmark)

    Müller, Ralf; Shao, Jingting; Pemsel, Sofia

    and their relationships to organizational success. Based on these results, the authors discovered that organizational enablers (including key factors such as leadership, governance, and influence of project managers) have a critical impact on how organizations operate, adapt to market fluctuations and forces, and make...... essential changes over time. This must-read book is a practical guide for executives and project managers alike. The insights and industry examples provided can be applied to any project-based organization......., Organizational Enablers for Project Governance, Ralf Müller, Jingting Shao, and Sofia Pemsel examine the interaction of governance and governmentality in various types of companies and demonstrate how these factors drive business success and influence project work, efficiency, and profitability. The data...

  3. Fluorescence Image Analyzer - FLIMA: software for quantitative analysis of fluorescence in situ hybridization.

    Science.gov (United States)

    Silva, H C M; Martins-Júnior, M M C; Ribeiro, L B; Matoso, D A

    2017-03-30

    The Fluorescence Image Analyzer (FLIMA) software was developed for the quantitative analysis of images generated by fluorescence in situ hybridization (FISH). Currently, the images of FISH are examined without a coefficient that enables a comparison between them. Through GD Graphics Library, the FLIMA software calculates the amount of pixels on image and recognizes each present color. The coefficient generated by the algorithm shows the percentage of marks (probes) hybridized on the chromosomes. This software can be used for any type of image generated by a fluorescence microscope and is able to quantify digoxigenin probes exhibiting a red color, biotin probes exhibiting a green color, and double-FISH probes (digoxigenin and biotin used together), where the white color is displayed.

  4. New Generation Sensor Web Enablement

    Directory of Open Access Journals (Sweden)

    Christoph Stasch

    2011-03-01

    Full Text Available Many sensor networks have been deployed to monitor Earth’s environment, and more will follow in the future. Environmental sensors have improved continuously by becoming smaller, cheaper, and more intelligent. Due to the large number of sensor manufacturers and differing accompanying protocols, integrating diverse sensors into observation systems is not straightforward. A coherent infrastructure is needed to treat sensors in an interoperable, platform-independent and uniform way. The concept of the Sensor Web reflects such a kind of infrastructure for sharing, finding, and accessing sensors and their data across different applications. It hides the heterogeneous sensor hardware and communication protocols from the applications built on top of it. The Sensor Web Enablement initiative of the Open Geospatial Consortium standardizes web service interfaces and data encodings which can be used as building blocks for a Sensor Web. This article illustrates and analyzes the recent developments of the new generation of the Sensor Web Enablement specification framework. Further, we relate the Sensor Web to other emerging concepts such as the Web of Things and point out challenges and resulting future work topics for research on Sensor Web Enablement.

  5. 'Ethos' Enabling Organisational Knowledge Creation

    Science.gov (United States)

    Matsudaira, Yoshito

    This paper examines knowledge creation in relation to improvements on the production line in the manufacturing department of Nissan Motor Company and aims to clarify embodied knowledge observed in the actions of organisational members who enable knowledge creation will be clarified. For that purpose, this study adopts an approach that adds a first, second, and third-person's viewpoint to the theory of knowledge creation. Embodied knowledge, observed in the actions of organisational members who enable knowledge creation, is the continued practice of 'ethos' (in Greek) founded in Nissan Production Way as an ethical basis. Ethos is knowledge (intangible) assets for knowledge creating companies. Substantiated analysis classifies ethos into three categories: the individual, team and organisation. This indicates the precise actions of the organisational members in each category during the knowledge creation process. This research will be successful in its role of showing the indispensability of ethos - the new concept of knowledge assets, which enables knowledge creation -for future knowledge-based management in the knowledge society.

  6. Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Rakovich Yury

    2008-01-01

    Full Text Available AbstractNanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional nanoscale devices, which could be manipulated using external magnetic fields. The aim of this review is to present an overview of bimodal “two-in-one” magnetic-fluorescent nanocomposite materials which combine both magnetic and fluorescent properties in one entity, in particular those with potential applications in biotechnology and nanomedicine. There is a great necessity for the development of these multifunctional nanocomposites, but there are some difficulties and challenges to overcome in their fabrication such as quenching of the fluorescent entity by the magnetic core. Fluorescent-magnetic nanocomposites include a variety of materials including silica-based, dye-functionalised magnetic nanoparticles and quantum dots-magnetic nanoparticle composites. The classification and main synthesis strategies, along with approaches for the fabrication of fluorescent-magnetic nanocomposites, are considered. The current and potential biomedical uses, including biological imaging, cell tracking, magnetic bioseparation, nanomedicine and bio- and chemo-sensoring, of magnetic-fluorescent nanocomposites are also discussed.

  7. Fluorenyl benzothiadiazole and benzoselenadiazole near-IR fluorescent probes for two-photon fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Belfield, Kevin D.; Yao, Sheng; Kim, Bosung; Yue, Xiling

    2016-03-01

    Imaging biological samples with two-photon fluorescence (2PF) microscopy has the unique advantage of resulting high contrast 3D resolution subcellular image that can reach up to several millimeters depth. 2PF probes that absorb and emit at near IR region need to be developed. Two-photon excitation (2PE) wavelengths are less concerned as 2PE uses wavelengths doubles the absorption wavelength of the probe, which means 2PE wavelengths for probes even with absorption at visible wavelength will fall into NIR region. Therefore, probes that fluoresce at near IR region with high quantum yields are needed. A series of dyes based on 5-thienyl-2, 1, 3-benzothiadiazole and 5-thienyl-2, 1, 3-benzoselenadiazole core were synthesized as near infrared two-photon fluorophores. Fluorescence maxima wavelengths as long as 714 nm and fluorescence quantum yields as high as 0.67 were achieved. The fluorescence quantum yields of the dyes were nearly constant, regardless of solvents polarity. These diazoles exhibited large Stokes shift (fluorescence figure of merit (FM , 1.04×10-2 GM). Cells incubated on a 3D scaffold with one of the new probes (encapsulated in Pluronic micelles) exhibited bright fluorescence, enabling 3D two-photon fluorescence imaging to a depth of 100 µm.

  8. Venture Capitalist Enabled Entrepreneurial Mentoring

    DEFF Research Database (Denmark)

    Agrawal, Anirudh

    2018-01-01

    -up entrepreneur. Using some interviews and secondary data from three Indian VC firms, this chapter explores the VC and investee enterprise mentoring within the Indian start-up ecosystem, The data analysis suggests that factors for the best outcomes include VCs that are highly networked‚ intensively sector focused......, have entrepreneurs as investors, and that engage frequently with investees over managerial and market issues. Using these cases, this study proposes an antecedent‚ action and outcome model of venture capital enabled entrepreneurial mentoring in India. This model can be expanded in the global context....

  9. Optimized microsystems-enabled photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Campa, Jose Luis; Nielson, Gregory N.; Young, Ralph W.; Resnick, Paul J.; Okandan, Murat; Gupta, Vipin P.

    2015-09-22

    Technologies pertaining to designing microsystems-enabled photovoltaic (MEPV) cells are described herein. A first restriction for a first parameter of an MEPV cell is received. Subsequently, a selection of a second parameter of the MEPV cell is received. Values for a plurality of parameters of the MEPV cell are computed such that the MEPV cell is optimized with respect to the second parameter, wherein the values for the plurality of parameters are computed based at least in part upon the restriction for the first parameter.

  10. Concentrators using fluorescent substances

    Energy Technology Data Exchange (ETDEWEB)

    Hayashibara, M.; Tsukamoto, M. (Hitachi Seisakusho K.K., Tokyo (Japan))

    1990-01-01

    In luminescent concentrators - plates of polymethylmethacrylate (PMMA) or other transparent material with a fluorescent compound dispersed within them - incident light is trapped and concentrated by internal reflection, and shifted to a longer wavelength, as it interacts with fluorescent particles. Experience with the use of luminescent concentrators for electricity generation in conjunction with solar cells, in solar heaters, in amplifiers for light intensity, in long-wave converters and in display panels is discussed. Solar energy conversion efficiencies of 4-5% have been obtained in generating systems combining concentrators containing Fluorol 555 or Rhodamin 6G with GaAs solar cells. (author).

  11. Smartphone fluorescence spectroscopy

    Science.gov (United States)

    Yu, Hojoeng; Tan, Yafang; Cunningham, Brian T.

    2014-03-01

    We demonstrate the first use of smartphone spectrophotometry for readout of fluorescence-based biological assays. We evaluated the smartphone fluorimeter in the context of a fluorescent molecular beacon (MB) assay for detection of a specific nucleic acid sequences in a liquid test sample. The capability of distinguishing a one-point mismatch is also demonstrated by detecting single-base mutation in target nucleic acids. Our approach offers a route towards portable biomolecular assays for viral/bacterial pathogens, disease biomarkers, and toxins.

  12. Smartphone fluorescence spectroscopy.

    Science.gov (United States)

    Yu, Hojeong; Tan, Yafang; Cunningham, Brian T

    2014-09-02

    We demonstrate the first use of smartphone spectrophotometry for readout of fluorescence-based biological assays. We evaluated the smartphone fluorimeter in the context of a fluorescent molecular beacon (MB) assay for detection of specific nucleic acid sequences in a liquid test sample and compared performance against a conventional laboratory fluorimeter. The capability of distinguishing a one-point mismatch is also demonstrated by detecting single-base mutation in target nucleic acids. Our approach offers a route toward portable biomolecular assays for viral/bacterial pathogens, disease biomarkers, and toxins.

  13. Deep UV Raman/Fluorescence (DUV-RF) Stand-Off Sensor for Lunar Science Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal enables development a miniature, low power consumption, fused deep UV Raman and native fluorescence (DUV-RF) stand-off sensor. The proposed fused...

  14. Intracellular temperature measurements with fluorescent polymeric thermometers.

    Science.gov (United States)

    Uchiyama, Seiichi; Gota, Chie; Tsuji, Toshikazu; Inada, Noriko

    2017-10-05

    In 2003, we successfully created the first fluorescent polymeric thermometer by combining a thermo-responsive polymer and an environment-sensitive (polarity and hydrogen bonding-sensitive) fluorophore. Its high sensitivity to temperature variation and high hydrophilicity, even under conditions of high ionic strength, enabled intracellular temperature measurements. Along with the progress of our research projects, the development of new luminescent molecular thermometers and the establishment of novel methods for measuring intracellular temperature have matured in this field. In this Feature Article, we summarize the background and history of intracellular temperature measurements using fluorescent polymeric thermometers based on studies performed in our laboratory and the relationship between our methods and those of other eminent research groups. Future research directions regarding intracellular temperature measurements are also discussed.

  15. Nanomaterial-enabled neural stimulation

    Directory of Open Access Journals (Sweden)

    Yongchen eWang

    2016-03-01

    Full Text Available Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  16. Enabling Exploration Through Docking Standards

    Science.gov (United States)

    Hatfield, Caris A.

    2012-01-01

    Human exploration missions beyond low earth orbit will likely require international cooperation in order to leverage limited resources. International standards can help enable cooperative missions by providing well understood, predefined interfaces allowing compatibility between unique spacecraft and systems. The International Space Station (ISS) partnership has developed a publicly available International Docking System Standard (IDSS) that provides a solution to one of these key interfaces by defining a common docking interface. The docking interface provides a way for even dissimilar spacecraft to dock for exchange of crew and cargo, as well as enabling the assembly of large space systems. This paper provides an overview of the key attributes of the IDSS, an overview of the NASA Docking System (NDS), and the plans for updating the ISS with IDSS compatible interfaces. The NDS provides a state of the art, low impact docking system that will initially be made available to commercial crew and cargo providers. The ISS will be used to demonstrate the operational utility of the IDSS interface as a foundational technology for cooperative exploration.

  17. Europium enabled luminescent nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Syamchand, S.S., E-mail: syamchand.ss@gmail.com; Sony, G., E-mail: emailtosony@gmail.com

    2015-09-15

    Lanthanide based nanoparticles are receiving great attention ought to their excellent luminescent and magnetic properties and find challenging biomedical applications. Among the luminescent lanthanide NPs, europium based NPs (Eu-NPs) are better candidates for immunoassay and imaging applications. The Eu-NPs have an edge over quantum dots (QDs) by means of their stable luminescence, long fluorescence lifetime, sharp emission peaks with narrow band width, lack of blinking and biocompatibility. This review surveys the synthesis and properties of a variety of Eu-NPs consolidated from different research articles, for their applications in medicine and biology. The exquisite luminescent properties of Eu-NPs are explored for developing biomedical applications such as immunoassay and bioimaging including multimodal imaging. The biomedical applications of Eu-NPs are mostly diagnostic in nature and mainly focus on various key analytes present in biological systems. The luminescent properties of europium enabled NPs are influenced by a number of factors such as the site symmetry, the metal nanoparticles, metal ions, quantum dots, surfactants, morphology of Eu-NPs, crystal defect, phenomena like antenna effect and physical parameters like temperature. Through this review we explore and assimilate all the factors which affect the luminescence in Eu-NPs and coil a new thread of parameters that control the luminescence in Eu-NPs, which would provide further insight in developing Eu-based nanoprobes for future biomedical prospects. - Highlights: • The review describes 14 major factors that influence the luminescence properties of europium enabled luminescent nanoparticles (Eu-NPs). • Surveys different types of europium containing nanoparticles that have been reported for their biomedical applications. • Eu-NPs are conveniently divided into four different categories, based on the type of the substrates involved. The four categories are (1) virgin Eu-substrate based NPs; (2

  18. Binary Fluorescence Labeling for the Recovery of Polymeric Materials for Recycling

    OpenAIRE

    Langhals, Heinz; Schmid, Tanja; Herman, Markus; Zwiener, Matthias; Hofer, Alexander

    2013-01-01

    Fluorescent perylene derivatives for the invisible digital coding of polymers were reported where a binary combination of fluorescent doping allows the unambiguous identification of the polymers for sorting. The mono-material recovery of the polymeric materials is an important prerequisite for the high-performance application of recycled material and was enabled by the application of optical methods.

  19. Instant live-cell super-resolution imaging of cellular structures by nanoinjection of fluorescent probes.

    Science.gov (United States)

    Hennig, Simon; van de Linde, Sebastian; Lummer, Martina; Simonis, Matthias; Huser, Thomas; Sauer, Markus

    2015-02-11

    Labeling internal structures within living cells with standard fluorescent probes is a challenging problem. Here, we introduce a novel intracellular staining method that enables us to carefully control the labeling process and provides instant access to the inner structures of living cells. Using a hollow glass capillary with a diameter of cell-permeable and nonpermeable fluorescent probes to cells.

  20. Hyperspectral Fluorescence and Reflectance Imaging Instrument

    Science.gov (United States)

    Ryan, Robert E.; O'Neal, S. Duane; Lanoue, Mark; Russell, Jeffrey

    2008-01-01

    wavelength light-emitting-diode (LED) sources and white-light LED sources designed to produce consistently spatially stable light. White LEDs provide illumination for the measurement of reflectance spectra, while narrowband blue and UV LEDs are used to excite fluorescence. Each spectral type of LED can be turned on or off depending on the specific remote-sensing process being performed. Uniformity of illumination is achieved by using an array of LEDs and/or an integrating sphere or other diffusing surface. The image plane scanner uses a fore optic with a field of view large enough to provide an entire scan line on the image plane. It builds up a two-dimensional image in pushbroom fashion as the target is scanned across the image plane either by moving the object or moving the fore optic. For fluorescence detection, spectral filtering of a narrowband light illumination source is sometimes necessary to minimize the interference of the source spectrum wings with the fluorescence signal. Spectral filtering is achieved with optical interference filters and absorption glasses. This dual spectral imaging capability will enable the optimization of reflective, fluorescence, and fused datasets as well as a cost-effective design for multispectral imaging solutions. This system has been used in plant stress detection studies and in currency analysis.

  1. Temperature-dependent fluorescence lifetime of a fluorescent polymeric thermometer, poly(N-isopropylacrylamide), labeled by polarity and hydrogen bonding sensitive 4-sulfamoyl-7-aminobenzofurazan.

    Science.gov (United States)

    Gota, Chie; Uchiyama, Seiichi; Yoshihara, Toshitada; Tobita, Seiji; Ohwada, Tomohiko

    2008-03-13

    Fluorescent molecular thermometers showing temperature-dependent fluorescence lifetimes enable thermal mapping of small spaces such as a microchannel and a living cell. We report the temperature-dependent fluorescence lifetimes of poly(NIPAM-co-DBD-AA), which is a random copolymer of N-isopropylacrylamide (NIPAM) and an environment-sensitive fluorescent monomer (DBD-AA) containing a 4-sulfamoyl-7-aminobenzofurazan structure. The average fluorescence lifetime of poly(NIPAM-co-DBD-AA) in aqueous solution increased from 4.22 to 14.1 ns with increasing temperature from 30 to 35 degrees C. This drastic change in fluorescence lifetime (27% increase per 1 degrees C) is the sharpest ever reported. Concentration independency, one of the advantages of fluorescence lifetime measurements, was seen in average fluorescence lifetime (13.7 +/- 0.18 ns) of poly(NIPAM-co-DBD-AA) at 33 degrees C over a wide concentration range (0.005-1 w/v%). With increasing temperature, polyNIPAM units in poly(NIPAM-co-DBD-AA) change their structure from an extended form to a globular form, providing apolar and aprotic environments to the fluorescent DBD-AA units. Consequently, the environment-sensitive DBD-AA units translate the local environmental changes into the extension of the fluorescence lifetime. This role of the DBD-AA units was revealed by a study of solvent effects on fluorescence lifetime of a model environment-sensitive fluorophore.

  2. Context-Enabled Business Intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Troy Hiltbrand

    2012-04-01

    To truly understand context and apply it in business intelligence, it is vital to understand what context is and how it can be applied in addressing organizational needs. Context describes the facets of the environment that impact the way that end users interact with the system. Context includes aspects of location, chronology, access method, demographics, social influence/ relationships, end-user attitude/ emotional state, behavior/ past behavior, and presence. To be successful in making Business Intelligence content enabled, it is important to be able to capture the context of use user. With advances in technology, there are a number of ways in which this user based information can be gathered and exposed to enhance the overall end user experience.

  3. Simulation Enabled Safeguards Assessment Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Robert Bean; Trond Bjornard; Thomas Larson

    2007-09-01

    It is expected that nuclear energy will be a significant component of future supplies. New facilities, operating under a strengthened international nonproliferation regime will be needed. There is good reason to believe virtual engineering applied to the facility design, as well as to the safeguards system design will reduce total project cost and improve efficiency in the design cycle. Simulation Enabled Safeguards Assessment MEthodology (SESAME) has been developed as a software package to provide this capability for nuclear reprocessing facilities. The software architecture is specifically designed for distributed computing, collaborative design efforts, and modular construction to allow step improvements in functionality. Drag and drop wireframe construction allows the user to select the desired components from a component warehouse, render the system for 3D visualization, and, linked to a set of physics libraries and/or computational codes, conduct process evaluations of the system they have designed.

  4. Enablers and constrainers to participation

    DEFF Research Database (Denmark)

    Desjardins, Richard; Milana, Marcella

    2007-01-01

    as to construct a tool for analyzing the targeting of adult learning policy, with regard to both its coverage and expected consequences. Our aim is to develop a means for a more in-depth analysis of the match-mismatch of public policy and persisting constraints to participation.......This paper briefly reviews some of evidence on participation patterns in Nordic countries and some of the defining parameters that may explain the observations. This is done in a comparative perspective by contrasting results from the 2003 Eurobarometer data between Nordic countries and a handful...... of non-Nordic countries. An emphasis is placed on the constraining and enabling elements to participation and how these may explain why certain groups participate more or less than others. A central question of interest to this paper is to what extent does (can) government intervention interact...

  5. Informatics enables public health surveillance

    Directory of Open Access Journals (Sweden)

    Scott J. N McNabb

    2017-01-01

    Full Text Available Over the past decade, the world has radically changed. New advances in information and communication technologies (ICT connect the world in ways never imagined. Public health informatics (PHI leveraged for public health surveillance (PHS, can enable, enhance, and empower essential PHS functions (i.e., detection, reporting, confirmation, analyses, feedback, response. However, the tail doesn't wag the dog; as such, ICT cannot (should not drive public health surveillance strengthening. Rather, ICT can serve PHS to more effectively empower core functions. In this review, we explore promising ICT trends for prevention, detection, and response, laboratory reporting, push notification, analytics, predictive surveillance, and using new data sources, while recognizing that it is the people, politics, and policies that most challenge progress for implementation of solutions.

  6. Genome-enabled plant metabolomics.

    Science.gov (United States)

    Tohge, Takayuki; de Souza, Leonardo Perez; Fernie, Alisdair R

    2014-09-01

    The grand challenge currently facing metabolomics is that of comprehensitivity whilst next generation sequencing and advanced proteomics methods now allow almost complete and at least 50% coverage of their respective target molecules, metabolomics platforms at best offer coverage of just 10% of the small molecule complement of the cell. Here we discuss the use of genome sequence information as an enabling tool for peak identity and for translational metabolomics. Whilst we argue that genome information is not sufficient to compute the size of a species metabolome it is highly useful in predicting the occurrence of a wide range of common metabolites. Furthermore, we describe how via gene functional analysis in model species the identity of unknown metabolite peaks can be resolved. Taken together these examples suggest that genome sequence information is current (and likely will remain), a highly effective tool in peak elucidation in mass spectral metabolomics strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Fluorescent polymers from non-fluorescent photoreactive monomers.

    Science.gov (United States)

    Mueller, Jan O; Voll, Dominik; Schmidt, Friedrich G; Delaittre, Guillaume; Barner-Kowollik, Christopher

    2014-12-25

    A facile, fast and ambient-temperature avenue towards highly fluorescent polymers is introduced via polymerizing non-fluorescent photoreactive monomers based on light-induced NITEC chemistry, providing a platform technology for fluorescent polymers. The resulting polypyrazolines were analyzed in depth and the photo-triggered step-growth process was monitored in a detailed kinetic study.

  8. Fundamentals of fluorescence microscopy exploring life with light

    CERN Document Server

    Mondal, Partha Pratim

    2014-01-01

    This book starts at an introductory level and leads reader to the most advanced developments in fluorescence imaging and super-resolution techniques that have enabled the emergence of new disciplines such as nanobioimaging, multiphoton microscopy, photodynamic therapy, nanometrology and nanosensors. The interdisciplinary subject of fluorescence microscopy and imaging requires complete knowledge of imaging optics and molecular physics. So, this book approaches the subject by introducing optical imaging concepts before going deep into the advanced imaging systems and their applications. Molecular orbital theory forms the basis for understanding fluorescent molecules and thereby facilitates complete explanation of light-matter interaction at the geometrical focus. The two disciplines have some overlap since light controls the states of molecules and conversely, molecular states control the emitted light. These two mechanisms together determine essential fluorescence  factors and phenomena such as, molecular cro...

  9. 3-Dimensional reconstruction of fluorescent structures in tardigrades

    Directory of Open Access Journals (Sweden)

    Franz BRÜMMER

    2007-09-01

    Full Text Available Tardigrades are microscopic animals, thus brightfield microscopy is a well established method for tardigrade observation. Modern techniques in functional genetics like fluorescence in situ hybridisation or fluorescently labelled expression markers demand high resolution fluorescence microscopy. Nevertheless tardigrades are still considered to be difficult objects for fluorescence techniques as they are covered by an opaque and diffracting cuticle. We show a modern technique of structured light illumination that enables us to acquire thin optical sections and consequently to reconstruct 3-dimensional structures in tardigrades with a high spatial resolution in all 3 dimensions. This technique is evaluated on taxonomically valuable internal as well as external structures of eutardigrades: the bucco-pharyngeal apparatus and the claws. The 3-dimensional reconstructions allow the measurement of distances in all 3 dimensions.

  10. Protein subcellular localization assays using split fluorescent proteins

    Science.gov (United States)

    Waldo, Geoffrey S [Santa Fe, NM; Cabantous, Stephanie [Los Alamos, NM

    2009-09-08

    The invention provides protein subcellular localization assays using split fluorescent protein systems. The assays are conducted in living cells, do not require fixation and washing steps inherent in existing immunostaining and related techniques, and permit rapid, non-invasive, direct visualization of protein localization in living cells. The split fluorescent protein systems used in the practice of the invention generally comprise two or more self-complementing fragments of a fluorescent protein, such as GFP, wherein one or more of the fragments correspond to one or more beta-strand microdomains and are used to "tag" proteins of interest, and a complementary "assay" fragment of the fluorescent protein. Either or both of the fragments may be functionalized with a subcellular targeting sequence enabling it to be expressed in or directed to a particular subcellular compartment (i.e., the nucleus).

  11. Visualization of differential gene expression by improved cyan fluorescent protein and yellow fluorescent protein production in Bacillus subtilis

    NARCIS (Netherlands)

    Veening, JW; Smits, WK; Hamoen, LW; Jongbloed, JDH; Kuipers, OP; Smits, Wiep Klaas

    2004-01-01

    The distinguishable cyan and yellow fluorescent proteins (CFP and YFP) enable the simultaneous in vivo visualization of different promoter activities. Here, we report new cloning vectors for the construction of cfp and yfp fusions in Bacillus subtilis. By extending the N-terminal portions of

  12. Fluorescence Microscopy of Single Molecules

    Science.gov (United States)

    Zimmermann, Jan; van Dorp, Arthur; Renn, Alois

    2004-01-01

    The investigation of photochemistry and photophysics of individual quantum systems is described with the help of a wide-field fluorescence microscopy approach. The fluorescence single molecules are observed in real time.

  13. Fluorescence spectroscopy in polymer science

    NARCIS (Netherlands)

    Raja, T.N.; Brouwer, A.M.; Demchenko, A.P.

    2011-01-01

    Polymer science is an interdisciplinary field, combining chemistry, physics, and in some cases biology. Structure, morphology, and dynamical phenomena in natural and synthetic polymers can be addressed using fluorescence spectroscopy. The most attractive aspect of fluorescent reporters is that their

  14. Who's who in fluorescence 2008

    CERN Document Server

    Geddes, Chris D

    2008-01-01

    The Journal of Fluorescence's sixth Who's Who directory publishes the names, contact details, specialty keywords, and a brief description of scientists employing fluorescence methodology and instrumentation in their working lives. This is a unique reference.

  15. A 3D printed fluidic device that enables integrated features.

    Science.gov (United States)

    Anderson, Kari B; Lockwood, Sarah Y; Martin, R Scott; Spence, Dana M

    2013-06-18

    Fluidic devices fabricated using conventional soft lithography are well suited as prototyping methods. Three-dimensional (3D) printing, commonly used for producing design prototypes in industry, allows for one step production of devices. 3D printers build a device layer by layer based on 3D computer models. Here, a reusable, high throughput, 3D printed fluidic device was created that enables flow and incorporates a membrane above a channel in order to study drug transport and affect cells. The device contains 8 parallel channels, 3 mm wide by 1.5 mm deep, connected to a syringe pump through standard, threaded fittings. The device was also printed to allow integration with commercially available membrane inserts whose bottoms are constructed of a porous polycarbonate membrane; this insert enables molecular transport to occur from the channel to above the well. When concentrations of various antibiotics (levofloxacin and linezolid) are pumped through the channels, approximately 18-21% of the drug migrates through the porous membrane, providing evidence that this device will be useful for studies where drug effects on cells are investigated. Finally, we show that mammalian cells cultured on this membrane can be affected by reagents flowing through the channels. Specifically, saponin was used to compromise cell membranes, and a fluorescent label was used to monitor the extent, resulting in a 4-fold increase in fluorescence for saponin treated cells.

  16. A fluorescence scanning electron microscope

    OpenAIRE

    Kanemaru, Takaaki; Hirata, Kazuho; Takasu, Shin-ichi; Isobe, Shin-Ichiro; Mizuki, Keiji; Mataka, Shuntaro; Nakamura, Kei-ichiro

    2010-01-01

    Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM) and an electron microscope (EM). In the current study, a scanning electron microscope (SEM) (JEOL JXA8600 M) was combined with a fluorescence digital c...

  17. Important innovation enablers for innovation teams

    OpenAIRE

    Johnsson, Mikael

    2016-01-01

    This research aims to study if innovation enablers (Enablers), i.e. factors that enable innovation work, are important for innovation teams in on-going innovation work and if lack of Enablers affects innovation projects negatively. The background to this study is that prior research states that numerous factors are important for innovation work, but there’s still knowledge to gain whatever these Enablers are perceived to be important by innovation teams. Data from three innovation teams on-go...

  18. Simultaneous neuron- and astrocyte-specific fluorescent marking

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Wiebke [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Hayata-Takano, Atsuko [Molecular Research Center for Children' s Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kamo, Toshihiko [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nakazawa, Takanobu, E-mail: takanobunakazawa-tky@umin.ac.jp [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Kazuki [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kasai, Atsushi; Seiriki, Kaoru [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Interdisciplinary Program for Biomedical Sciences, Institute for Academic Initiatives, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Shintani, Norihito [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ago, Yukio [Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Farfan, Camille [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); and others

    2015-03-27

    Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains. - Highlights: • We develop a method for the specific fluorescent labeling of neurons and astrocytes. • Neuron-specific labeling is achieved using Scg10 and synapsin promoters. • Astrocyte-specific labeling is generated using the minimal GFAP promoter. • Nuclear localization of fluorescent proteins is achieved with histone 2B protein.

  19. pH-switchable bacteria detection using zwitterionic fluorescent polymer.

    Science.gov (United States)

    Khoerunnisa; Mazrad, Zihnil A I; In, Insik; Park, Sung Young

    2017-04-15

    A zwitterionic fluorescent polymer with high sensitivity to pH changes was constructed for the detection and imaging of both gram-positive and gram-negative pathogenic bacteria. A detection probe using the zwitterionic fluorescent polymer was synthesized with single boron dipyrromethane (BODIPY) as a hydrophobic dye and bromoethane as a cationic group for bacteria binding with conjugated poly(sulfobetaine methacrylate) (BOD/BE-PSM). The zwitterionic fluorescent polymer bound to bacteria through ionic complexes between anionic groups on the bacterial surface and cationic BOD/BE-PSM groups after 1h incubation. This finding demonstrated that the fluorescence on/off system operated via changes in the hydrophilic and hydrophobic nature of the zwitterionic fluorescent polymer, depending on the pH (6.0, 7.4, or 9.0), at a fixed 1mg/mL polymer concentration. The system showed good stability with a limit of detection of 1mg/mL. Quenching caused by interactions with the hydrophobic BODIPY dye was also observed, enabling bacteria detection, as shown by fluorescence spectroscopy and confocal microscopy images. Our results indicated that the zwitterionic fluorescent polymer could be used to detect bacteria over a wide range of pH values. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Who's who in fluorescence 2005

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    The Journal of Fluorescence's third Who's Who directory publishes the names, contact details, specialty keywords, photographs, and a brief description of scientists employing fluorescence methodology and instrumentation in their working livesThe directory provides company contact details with a brief list of fluorescence-related products.

  1. Enabling technology for human collaboration.

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Tim Andrew (MindTel, LLC, Syracuse, NY); Jones, Wendell Bruce; Warner, David Jay (MindTel, LLC, Syracuse, NY); Doser, Adele Beatrice; Johnson, Curtis Martin; Merkle, Peter Benedict

    2003-11-01

    This report summarizes the results of a five-month LDRD late start project which explored the potential of enabling technology to improve the performance of small groups. The purpose was to investigate and develop new methods to assist groups working in high consequence, high stress, ambiguous and time critical situations, especially those for which it is impractical to adequately train or prepare. A testbed was constructed for exploratory analysis of a small group engaged in tasks with high cognitive and communication performance requirements. The system consisted of five computer stations, four with special devices equipped to collect physiologic, somatic, audio and video data. Test subjects were recruited and engaged in a cooperative video game. Each team member was provided with a sensor array for physiologic and somatic data collection while playing the video game. We explored the potential for real-time signal analysis to provide information that enables emergent and desirable group behavior and improved task performance. The data collected in this study included audio, video, game scores, physiological, somatic, keystroke, and mouse movement data. The use of self-organizing maps (SOMs) was explored to search for emergent trends in the physiological data as it correlated with the video, audio and game scores. This exploration resulted in the development of two approaches for analysis, to be used concurrently, an individual SOM and a group SOM. The individual SOM was trained using the unique data of each person, and was used to monitor the effectiveness and stress level of each member of the group. The group SOM was trained using the data of the entire group, and was used to monitor the group effectiveness and dynamics. Results suggested that both types of SOMs were required to adequately track evolutions and shifts in group effectiveness. Four subjects were used in the data collection and development of these tools. This report documents a proof of concept

  2. Enabling Participation In Exoplanet Science

    Science.gov (United States)

    Taylor, Stuart F.

    2015-08-01

    Determining the distribution of exoplanets has required the contributions of a community of astronomers, who all require the support of colleagues to finish their projects in a manner to enable them to enter new collaborations to continue to contribute to understanding exoplanet science.The contributions of each member of the astronomy community are to be encouraged and must never be intentionally obstructed.We present a member’s long pursuit to be a contributing part of the exoplanet community through doing transit photometry as a means of commissioning the telescopes for a new observatory, followed by pursuit of interpreting the distributions in exoplanet parameter data.We present how the photometry projects have been presented as successful by the others who have claimed to have completed them, but how by requiring its employees to present results while omitting one member has been obstructive against members working together and has prevented the results from being published in what can genuinely be called a peer-reviewed fashion.We present how by tolerating one group to obstruct one member from finishing participation and then falsely denying credit is counterproductive to doing science.We show how expecting one member to attempt to go around an ostracizing group by starting something different is destructive to the entire profession. We repeat previously published appeals to help ostracized members to “go around the observatory” by calling for discussion on how the community must act to reverse cases of shunning, bullying, and other abuses. Without better recourse and support from the community, actions that do not meet standard good collegial behavior end up forcing good members from the community. The most important actions are to enable an ostracized member to have recourse to participating in group papers by either working through other authors or through the journal. All journals and authors must expect that no co-author is keeping out a major

  3. Light Sheet Fluorescence Microscopy

    Science.gov (United States)

    Santi, Peter A.

    2011-01-01

    Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with subcellular resolution. This method is well suited for imaging deep within transparent tissues or within whole organisms, and because tissues are exposed to only a thin plane of light, specimen photobleaching and phototoxicity are minimized compared to wide-field fluorescence, confocal, or multiphoton microscopy. LSFMs produce well-registered serial sections that are suitable for three-dimensional reconstruction of tissue structures. Because of a lack of a commercial LSFM microscope, numerous versions of light sheet microscopes have been constructed by different investigators. This review describes development of the technology, reviews existing devices, provides details of one LSFM device, and shows examples of images and three-dimensional reconstructions of tissues that were produced by LSFM. PMID:21339178

  4. Magnetic fluorescent lamp

    Science.gov (United States)

    Berman, S. M.; Richardson, R. W.

    1983-12-01

    The radiant emission of a mercury argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a zeeman splitting of approximately 1.7 times the thermal line width.

  5. Delayed fluorescence in photosynthesis.

    Science.gov (United States)

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  6. Magnetic fluorescent lamp

    Science.gov (United States)

    Berman, S.M.; Richardson R.W.

    1983-12-29

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  7. Fluorescent quantification of melanin

    OpenAIRE

    Fernandes, Bruno Pacheco; Matamá, Maria Teresa; Guimarães, Diana Isabel Pereira; Gomes, Andreia; Cavaco-Paulo, Artur

    2016-01-01

    Melanin quantification is reportedly performed by absorption spectroscopy, commonly at 405 nm. Here, we propose the implementation of fluorescence spectroscopy for melanin assessment. In a typical in vitro assay to assess melanin production in response to an external stimulus, absorption spectroscopy clearly overvalues melanin content. This method is also incapable of distinguishing non-melanotic/amelanotic control cells from those that are actually capable of performing melanogenesis. Theref...

  8. Fluorescent Lamp Replacement Study

    Science.gov (United States)

    2017-07-01

    recycling , and can be disposed safely in a landfill. (2) LEDs offer reduced maintenance costs and fewer bulb replacements, significantly reducing...housings, plastic grates, old wiring) and the new LED technology (cardboard packaging) were broken down and separated into the appropriate container for... recycling . Several fixtures, ballasts and energy efficient fluorescent bulbs that were determined to be in pristine condition were returned to ATC

  9. Global analysis of fluorescence decays to probe the internal dynamics of fluorescently labeled macromolecules.

    Science.gov (United States)

    Duhamel, Jean

    2014-03-11

    The aim of this review is to introduce the reader first to the mathematical complexity associated with the analysis of fluorescence decays acquired with solutions of macromolecules labeled with a fluorophore and its quencher that are capable of interacting with each other via photophysical processes within the macromolecular volume, second to the experimental and mathematical approaches that have been proposed over the years to handle this mathematical complexity, and third to the information that one can expect to retrieve with respect to the internal dynamics of such fluorescently labeled macromolecules. In my view, the ideal fluorophore-quencher pair to use in studying the internal dynamics of fluorescently labeled macromolecules would involve a long-lived fluorophore, a fluorophore and a quencher that do not undergo energy migration, and a photophysical process that results in a change in fluorophore emission upon contact between the excited fluorophore and quencher. Pyrene, with its ability to form an excimer on contact between excited-state and ground-state species, happens to possess all of these properties. Although the concepts described in this review apply to any fluorophore and quencher pair sharing pyrene's exceptional photophysical properties, this review focuses on the study of pyrene-labeled macromolecules that have been characterized in great detail over the past 40 years and presents the main models that are being used today to analyze the fluorescence decays of pyrene-labeled macromolecules reliably. These models are based on Birks' scheme, the DMD model, the fluorescence blob model, and the model free analysis. The review also provides a step-by-step protocol that should enable the noneducated user to achieve a successful decay analysis exempt of artifacts. Finally, some examples of studies of pyrene-labeled macromolecules are also presented to illustrate the different types of information that can be retrieved from these fluorescence decay

  10. CUDA Enabled Graph Subset Examiner

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-22

    Finding Godsil-McKay switching sets in graphs is one way to demonstrate that a specific graph is not determined by its spectrum--the eigenvalues of its adjacency matrix. An important area of active research in pure mathematics is determining which graphs are determined by their spectra, i.e. when the spectrum of the adjacency matrix uniquely determines the underlying graph. We are interested in exploring the spectra of graphs in the Johnson scheme and specifically seek to determine which of these graphs are determined by their spectra. Given a graph G, a Godsil-McKay switching set is an induced subgraph H on 2k vertices with the following properties: I) H is regular, ii) every vertex in G/H is adjacent to either 0, k, or 2k vertices of H, and iii) at least one vertex in G/H is adjacent to k vertices in H. The software package examines each subset of a user specified size to determine whether or not it satisfies those 3 conditions. The software makes use of the massive parallel processing power of CUDA enabled GPUs. It also exploits the vertex transitivity of graphs in the Johnson scheme by reasoning that if G has a Godsil-McKay switching set, then it has a switching set which includes vertex 1. While the code (in its current state) is tuned to this specific problem, the method of examining each induced subgraph of G can be easily re-written to check for any user specified conditions on the subgraphs and can therefore be used much more broadly.

  11. Enabling individualized therapy through nanotechnology.

    Science.gov (United States)

    Sakamoto, Jason H; van de Ven, Anne L; Godin, Biana; Blanco, Elvin; Serda, Rita E; Grattoni, Alessandro; Ziemys, Arturas; Bouamrani, Ali; Hu, Tony; Ranganathan, Shivakumar I; De Rosa, Enrica; Martinez, Jonathan O; Smid, Christine A; Buchanan, Rachel M; Lee, Sei-Young; Srinivasan, Srimeenakshi; Landry, Matthew; Meyn, Anne; Tasciotti, Ennio; Liu, Xuewu; Decuzzi, Paolo; Ferrari, Mauro

    2010-08-01

    Individualized medicine is the healthcare strategy that rebukes the idiomatic dogma of 'losing sight of the forest for the trees'. We are entering a new era of healthcare where it is no longer acceptable to develop and market a drug that is effective for only 80% of the patient population. The emergence of "-omic" technologies (e.g. genomics, transcriptomics, proteomics, metabolomics) and advances in systems biology are magnifying the deficiencies of standardized therapy, which often provide little treatment latitude for accommodating patient physiologic idiosyncrasies. A personalized approach to medicine is not a novel concept. Ever since the scientific community began unraveling the mysteries of the genome, the promise of discarding generic treatment regimens in favor of patient-specific therapies became more feasible and realistic. One of the major scientific impediments of this movement towards personalized medicine has been the need for technological enablement. Nanotechnology is projected to play a critical role in patient-specific therapy; however, this transition will depend heavily upon the evolutionary development of a systems biology approach to clinical medicine based upon "-omic" technology analysis and integration. This manuscript provides a forward looking assessment of the promise of nanomedicine as it pertains to individualized medicine and establishes a technology "snapshot" of the current state of nano-based products over a vast array of clinical indications and range of patient specificity. Other issues such as market driven hurdles and regulatory compliance reform are anticipated to "self-correct" in accordance to scientific advancement and healthcare demand. These peripheral, non-scientific concerns are not addressed at length in this manuscript; however they do exist, and their impact to the paradigm shifting healthcare transformation towards individualized medicine will be critical for its success. Copyright 2010 Elsevier Ltd. All rights

  12. Enabling individualized therapy through nanotechnology

    Science.gov (United States)

    Sakamoto, Jason H.; van de Ven, Anne L.; Godin, Biana; Blanco, Elvin; Serda, Rita E.; Grattoni, Alessandro; Ziemys, Arturas; Bouamrani, Ali; Hu, Tony; Ranganathan, Shivakumar I.; De Rosa, Enrica; Martinez, Jonathan O.; Smid, Christine A.; Buchanan, Rachel M.; Lee, Sei-Young; Srinivasan, Srimeenakshi; Landry, Matthew; Meyn, Anne; Tasciotti, Ennio; Liu, Xuewu; Decuzzi, Paolo; Ferrari, Mauro

    2010-01-01

    Individualized medicine is the healthcare strategy that rebukes the idiomatic dogma of ‘losing sight of the forest for the trees’. We are entering a new era of healthcare where it is no longer acceptable to develop and market a drug that is effective for only 80% of the patient population. The emergence of “-omic” technologies (e.g. genomics, transcriptomics, proteomics, metabolomics) and advances in systems biology are magnifying the deficiencies of standardized therapy, which often provide little treatment latitude for accommodating patient physiologic idiosyncrasies. A personalized approach to medicine is not a novel concept. Ever since the scientific community began unraveling the mysteries of the genome, the promise of discarding generic treatment regimens in favor of patient-specific therapies became more feasible and realistic. One of the major scientific impediments of this movement towards personalized medicine has been the need for technological enablement. Nanotechnology is projected to play a critical role in patient-specific therapy; however, this transition will depend heavily upon the evolutionary development of a systems biology approach to clinical medicine based upon “-omic” technology analysis and integration. This manuscript provides a forward looking assessment of the promise of nanomedicine as it pertains to individualized medicine and establishes a technology “snapshot” of the current state of nano-based products over a vast array of clinical indications and range of patient specificity. Other issues such as market driven hurdles and regulatory compliance reform are anticipated to “self-correct” in accordance to scientific advancement and healthcare demand. These peripheral, non-scientific concerns are not addressed at length in this manuscript; however they do exist, and their impact to the paradigm shifting healthcare transformation towards individualized medicine will be critical for its success. PMID:20045055

  13. Blue fluorescent cGMP sensor for multiparameter fluorescence imaging.

    Directory of Open Access Journals (Sweden)

    Yusuke Niino

    Full Text Available Cyclic GMP (cGMP regulates many physiological processes by cooperating with the other signaling molecules such as cyclic AMP (cAMP and Ca(2+. Genetically encoded sensors for cGMP have been developed based on fluorescence resonance energy transfer (FRET between fluorescent proteins. However, to analyze the dynamic relationship among these second messengers, combined use of existing sensors in a single cell is inadequate because of the significant spectral overlaps. A single wavelength indicator is an effective alternative to avoid this problem, but color variants of a single fluorescent protein-based biosensor are limited. In this study, to construct a new color fluorescent sensor, we converted the FRET-based sensor into a single wavelength indicator using a dark FRET acceptor. We developed a blue fluorescent cGMP biosensor, which is spectrally compatible with a FRET-based cAMP sensor using cyan and yellow fluorescent proteins (CFP/YFP. We cotransfected them and loaded a red fluorescent probe for Ca(2+ into cells, and accomplished triple-parameter fluorescence imaging of these cyclic nucleotides and Ca(2+, confirming the applicability of this combination to individually monitor their dynamics in a single cell. This blue fluorescent sensor and the approach using this FRET pair would be useful for multiparameter fluorescence imaging to understand complex signal transduction networks.

  14. A pH-sensitive red fluorescent protein compatible with hydrophobic resin embedding

    Science.gov (United States)

    Guo, Wenyan; Gang, Yadong; Liu, Xiuli; Zhou, Hongfu; Zeng, Shaoqun

    2017-02-01

    pH sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EYFP or EGFP improved from GFP in jellyfish are good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is of urgent need. Here a pH sensitive red fluorescent protein, pHuji, is selected and verified to be compatible with hydrophobic resin embedding and thus may be promising for dual-colour chemical reactivation imaging in conjunction with EGFP or EYFP.

  15. Molecular cytogenetics using fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  16. 5-Aminolevulinic acid fluorescence in high grade glioma surgery: surgical outcome, intraoperative findings, and fluorescence patterns.

    Science.gov (United States)

    Della Puppa, Alessandro; Ciccarino, Pietro; Lombardi, Giuseppe; Rolma, Giuseppe; Cecchin, Diego; Rossetto, Marta

    2014-01-01

    5-Aminolevulinic acid (5-ALA) fluorescence is a validated technique for resection of high grade gliomas (HGG); the aim of this study was to evaluate the surgical outcome and the intraoperative findings in a consecutive series of patients. Clinical and surgical data from patients affected by HGG who underwent surgery guided by 5-ALA fluorescence at our Department between June 2011 and February 2014 were retrospectively evaluated. Surgical outcome was evaluated by assessing the resection rate as gross total resection (GTR) > 98% and GTR > 90%. We finally stratified data for recurrent surgery, tumor location, tumor size, and tumor grade (IV versus III grade sec. WHO). 94 patients were finally enrolled. Overall GTR > 98% and GTR > 90% was achieved in 93% and 100% of patients. Extent of resection (GTR > 98%) was dependent on tumor location, tumor grade (P < 0.05), and tumor size (P < 0.05). In 43% of patients the boundaries of fluorescent tissue exceeded those of tumoral tissue detected by neuronavigation, more frequently in larger (57%) (P < 0.01) and recurrent (60%) tumors. 5-ALA fluorescence in HGG surgery enables a GTR in 100% of cases even if selection of patients remains a main bias. Recurrent surgery, and location, size, and tumor grade can predict both the surgical outcome and the intraoperative findings.

  17. 5-Aminolevulinic Acid Fluorescence in High Grade Glioma Surgery: Surgical Outcome, Intraoperative Findings, and Fluorescence Patterns

    Directory of Open Access Journals (Sweden)

    Alessandro Della Puppa

    2014-01-01

    Full Text Available Background. 5-Aminolevulinic acid (5-ALA fluorescence is a validated technique for resection of high grade gliomas (HGG; the aim of this study was to evaluate the surgical outcome and the intraoperative findings in a consecutive series of patients. Methods. Clinical and surgical data from patients affected by HGG who underwent surgery guided by 5-ALA fluorescence at our Department between June 2011 and February 2014 were retrospectively evaluated. Surgical outcome was evaluated by assessing the resection rate as gross total resection (GTR>98% and GTR>90%. We finally stratified data for recurrent surgery, tumor location, tumor size, and tumor grade (IV versus III grade sec. WHO. Results. 94 patients were finally enrolled. Overall GTR>98% and GTR>90% was achieved in 93% and 100% of patients. Extent of resection (GTR>98% was dependent on tumor location, tumor grade (P<0.05, and tumor size (P<0.05. In 43% of patients the boundaries of fluorescent tissue exceeded those of tumoral tissue detected by neuronavigation, more frequently in larger (57% (P<0.01 and recurrent (60% tumors. Conclusions. 5-ALA fluorescence in HGG surgery enables a GTR in 100% of cases even if selection of patients remains a main bias. Recurrent surgery, and location, size, and tumor grade can predict both the surgical outcome and the intraoperative findings.

  18. Fluorescent imaging of cancerous tissues for targeted surgery

    Science.gov (United States)

    Bu, Lihong; Shen, Baozhong; Cheng, Zhen

    2014-01-01

    To maximize tumor excision and minimize collateral damage is the primary goal of cancer surgery. Emerging molecular imaging techniques have to “image-guided surgery” developing into “molecular imaging-guided surgery”, which is termed “targeted surgery” in this review. Consequently, the precision of surgery can be advanced from tissue-scale to molecule-scale, enabling “targeted surgery” to be a component of “targeted therapy”. Evidence from numerous experimental and clinical studies has demonstrated significant benefits of fluorescent imaging in targeted surgery with preoperative molecular diagnostic screening. Fluorescent imaging can help to improve intraoperative staging and enable more radical cytoreduction, detect obscure tumor lesions in special organs, highlight tumor margins, better map lymph node metastases, and identify important normal structures intraoperatively. Though limited tissue penetration of fluorescent imaging and tumor heterogeneity are two major hurdles for current targeted surgery, multimodality imaging and multiplex imaging may provide potential solutions to overcome these issues, respectively. Moreover, though many fluorescent imaging techniques and probes have been investigated, targeted surgery remains at a proof-of-principle stage. The impact of fluorescent imaging on cancer surgery will likely be realized through persistent interdisciplinary amalgamation of research in diverse fields. PMID:25064553

  19. In Situ Spatial Complementation of Aptamer-Mediated Recognition Enables Live-Cell Imaging of Native RNA Transcripts in Real Time.

    OpenAIRE

    Wang, Z; Luo, Y; Xie, X; Hu, X; Song, H; Zhao, Y; Shi, J; Wang, L; Glinsky, G; Chen, N; Lal, R; Fan, C

    2018-01-01

    Direct cellular imaging of the localization and dynamics of biomolecules helps to understand their function and reveals novel mechanisms at the single-cell resolution. In contrast to routine fluorescent-protein-based protein imaging, technology for RNA imaging remains less well explored because of the lack of enabling technology. Herein, we report the development of an aptamer-initiated fluorescence complementation (AiFC) method for RNA imaging by engineering a green fluorescence protein (GFP...

  20. Fluorescence Imaging Enabled Urethane-Doped Citrate-Based Biodegradable Elastomers

    OpenAIRE

    Zhang, Yi; Tran, Richard T.; Qattan, Ibrahim; Tsai, Yi-ting; Tang, Liping; Liu, Chao; Yang, Jian

    2013-01-01

    The field of tissue engineering and drug delivery calls for new measurement tools, non-invasive real-time assays, and design methods for the next wave of innovations. Based on our recent progress in developing intrinsically biodegradable photoluminescent polymers (BPLPs) without conjugating organic dyes or quantum dots, in this paper, we developed a new type urethane-doped biodegradable photoluminescent polymers (UBPLPs) that could potentially serve as a new tool to respond ...

  1. Transgenic fluorescent Plasmodium cynomolgi liver stages enable live imaging and purification of Malaria hypnozoite-forms

    NARCIS (Netherlands)

    Voorberg-van de Wel, A.; Zeeman, A.M.; Amsterdam, S.M. van; Berg, A. van den; Klooster, E.J.; Iwanaga, S.; Janse, C.J.; Gemert, G.J.A. van; Sauerwein, R.; Beenhakker, N.; Koopman, G.; Thomas, A.W.; Kocken, C.H.

    2013-01-01

    A major challenge for strategies to combat the human malaria parasite Plasmodium vivax is the presence of hypnozoites in the liver. These dormant forms can cause renewed clinical disease after reactivation through unknown mechanisms. The closely related non-human primate malaria P. cynomolgi is a

  2. Investigating dye performance and crosstalk in fluorescence enabled bioimaging using a model system

    DEFF Research Database (Denmark)

    Arppe, Riikka; R. Carro-Temboury, Miguel; Hempel, Casper

    2017-01-01

    in experimental conditions. Importantly, we here report considerable cross-talk of the dyes when exchanging excitation and emission settings. Additionally, bleaching was quantified. The proposed model makes it possible to test and benchmark staining procedures before these dyes are applied to more complex...

  3. Low-cost, High Performance Avalanche Photodiodes for Enabling High Sensitivity Bio-fluorescence Detection

    Science.gov (United States)

    2012-04-01

    224–231. 9. Muth , J. F.; Brown, J. D.; Johnson, M.A.L.; Yu, Shonghai; Kolbas, R. M.; Cook, Jr. J. W.; Schetzina, J. F. Absorption Coefficient and...OF COPIES ORGANIZATION 1 ADMNSTR ELEC DEFNS TECHL INFO CTR ATTN DTIC OCP 8725 JOHN J KINGMAN RD STE 0944 FT BELVOIR VA 22060-6218

  4. Determination of biological activity from fluorescence-lifetime measurements in Saccharomyces cerevisiae

    Science.gov (United States)

    Rudek, F.; Baselt, T.; Lempe, B.; Taudt, C.; Hartmann, P.

    2015-03-01

    The importance of fluorescence lifetime measurement as an optical analysis tool is growing. Many applications already exist in order to determine the fluorescence lifetime, but the majority of these require the addition of fluorescence-active substances to enable measurements. Every usage of such foreign materials has an associated risk. This paper investigates the use of auto-fluorescing substances in Saccharomyces cerevisiae (Baker's yeast) as a risk free alternative to fluorescence-active substance enabled measurements. The experimental setup uses a nitrogen laser with a pulse length of 350 ps and a wavelength of 337 nm. The excited sample emits light due to fluorescence of NADH/NADPH and collagen. A fast photodiode collects the light at the output of an appropriate high-pass edge-filter at 400 nm. Fluorescence lifetimes can be determined from the decay of the measurement signals, which in turn characterizes the individual materials and their surrounding environment. Information about the quantity of the fluorescence active substances can also be measured based on the received signal intensity. The correlation between the fluorescence lifetime and the metabolic state of Saccharomyces cerevisiae was investigated and is presented here.

  5. Fluorescent temperature sensor

    Science.gov (United States)

    Baker, Gary A [Los Alamos, NM; Baker, Sheila N [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

    2009-03-03

    The present invention is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

  6. Fluorescent Europium Chelate Stain

    Science.gov (United States)

    Scaff, W. L.; Dyer, D. L.; Mori, K.

    1969-01-01

    The europium chelate of 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (thenoyl-trifluoroacetone; TTA) is firmly bound to microorganisms. It fluoresces brightly at 613 nm with activation at 340 nm. Cells may be stained with 10−3m chelate in 50% ethyl alcohol, followed by washing with 50% ethyl alcohol. Equal or better stains are produced with 10−3m aqueous europium salt, water wash, and 10−2m aqueous TTA. A noncomplexing buffer should be used to maintain the pH at 6.5 to 6.8. Images PMID:4181107

  7. Wide Field-of-View Fluorescence Imaging of Coral Reefs

    Science.gov (United States)

    Treibitz, Tali; Neal, Benjamin P.; Kline, David I.; Beijbom, Oscar; Roberts, Paul L. D.; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys. PMID:25582836

  8. Development of a fluorescent cryocooler

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, B.C.; Buchwald, M.I.; Epstein, R.I.; Gosnell, T.R.; Mungan, C.E.

    1995-10-01

    Recent work at Los Alamos National Laboratory has demonstrated the physical principles for a new type of solid-state cryocooler based on anti-Stokes fluorescence. Design studies indicate that a vibration-free, low-mass ``fluorescent cryocooler`` could operate for years with efficiencies and cooling powers comparable to current commercial systems. This paper presents concepts for a fluorescent cryocooler, design considerations and expected performance.

  9. Diffraction phase and fluorescence microscopy.

    Science.gov (United States)

    Park, Yongkeun; Popescu, Gabriel; Badizadegan, Kamran; Dasari, Ramachandra R; Feld, Michael S

    2006-09-04

    We have developed diffraction phase and fluorescence (DPF) microscopy as a new technique for simultaneous quantitative phase imaging and epi-fluorescence investigation of live cells. The DPF instrument consists of an interference microscope, which is incorporated into a conventional inverted fluorescence microscope. The quantitative phase images are characterized by sub-nanometer optical path-length stability over periods from milliseconds to a cell lifetime. The potential of the technique for quantifying rapid nanoscale motions in live cells is demonstrated by experiments on red blood cells, while the composite phase-fluorescence imaging mode is exemplified with mitotic kidney cells.

  10. Fluorescent nanodiamonds for ultrasensitive detection

    Science.gov (United States)

    Kimball, Joseph; Shumilov, Dmytro; Maliwa, Badri; Zerda, T. W.; Rout, Bibhu; Fudala, Rafal; Raut, Sangram; Gryczynski, Ignacy; Simanek, Eric; Borejdo, Julian; Rich, Ryan; Akopova, Irina; Gryczynski, Zygmunt

    2014-03-01

    Fluorescent nanodiamonds (NDs) are new and emerging nanomaterials that have potential to be used as fluorescence imaging agents and also as a highly versatile platform for the controlled functionalization and delivery of a wide spectrum of therapeutic agents. We will utilize two experimental methods, TIRF, a relatively simple method based on total internal reflection fluorescence and SPRF, fluorescence enhanced by resonance coupling with surface plasmons. We estimate that the SPRF method will be 100 times sensitive than currently available similar detectors based on detectors. The ultimate goal of this research is to develop microarray platforms that could be used for sensitive, fast and inexpensive gene sequencing and protein detection.

  11. An NFC-Enabled CMOS IC for a Wireless Fully Implantable Glucose Sensor.

    Science.gov (United States)

    DeHennis, Andrew; Getzlaff, Stefan; Grice, David; Mailand, Marko

    2016-01-01

    This paper presents an integrated circuit (IC) that merges integrated optical and temperature transducers, optical interface circuitry, and a near-field communication (NFC)-enabled digital, wireless readout for a fully passive implantable sensor platform to measure glucose in people with diabetes. A flip-chip mounted LED and monolithically integrated photodiodes serve as the transduction front-end to enable fluorescence readout. A wide-range programmable transimpedance amplifier adapts the sensor signals to the input of an 11-bit analog-to-digital converter digitizing the measurements. Measurement readout is enabled by means of wireless backscatter modulation to a remote NFC reader. The system is able to resolve current levels of less than 10 pA with a single fluorescent measurement energy consumption of less than 1 μJ. The wireless IC is fabricated in a 0.6-μm-CMOS process and utilizes a 13.56-MHz-based ISO15693 for passive wireless readout through a NFC interface. The IC is utilized as the core interface to a fluorescent, glucose transducer to enable a fully implantable sensor-based continuous glucose monitoring system.

  12. Synthesis of Fluorescent Gelators and Direct Observation of Gelation with a Fluorescence Microscope.

    Science.gov (United States)

    Hanabusa, Kenji; Ueda, Takuya; Takata, Shingo; Suzuki, Masahiro

    2016-11-14

    Fluorescein-, benzothiazole-, quinoline-, stilbene-, and carbazole-containing fluorescent gelators have been synthesized by connecting gelation-driving segments, including l-isoleucine, l-valine, l-phenylalanine, l-leucine residue, cyclo(l-asparaginyl-l-phenylalanyl), and trans-(1R,2R)-diaminocyclohexane. The emission behaviors of the gelators were investigated, and their gelation abilities studied against 15 solvents. The minimum gel concentration, variable-temperature spectroscopy, transmission electron microscopy, scanning electron microscopy, fluorescence microscopy (FM), and confocal laser scanning microscopy (CLSM) were used to characterize gelation. The intermolecular hydrogen bonding between the N-H and C=O of amide, van der Waals interactions and π-π stacking play important roles in gelation. The colors of emission are related to the fluorescence structures of gelators. Fibrous aggregates characterized by the color of their emission were observed by FM. 3D images are produced by the superposition of images captured by CLSM every 0.1 μm to a settled depth. The 3D images show that the large micrometer-sized aggregates spread out three dimensionally. FM observations of mixed gelators are studied. In the case of gelation, two structurally related gelators with the same gelation-driving segment lead to the gelators build up of the same aggregates through similar hydrogen-bonding patterns. When two gelators with structurally different gelation-driving segments induce gelation, the gelators build up each aggregate through individual hydrogen-bonding patterns. A fluorescent reagent that was incorporated into the aggregates of gels through van der Waals interactions was developed. The addition of this fluorescent reagent enables the successful observation of nonfluorescent gelators' aggregates by FM. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Understanding microbial/DOM interactions using fluorescence and flow cytometry

    Science.gov (United States)

    Fox, Bethany; Rushworth, Cathy; Attridge, John; Anesio, Alexandre; Cox, Tim; Reynolds, Darren

    2015-04-01

    processing and subsequent production of DOM, will inform the development of a new generation of in situ fluorescence sensors. Ultimately, our aim is develop a novel technology that enables the monitoring of ecosystem health in freshwater aquatic systems.

  14. In vivo cellular imaging with microscopes enabled by MEMS scanners

    Science.gov (United States)

    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.

  15. Quantitative approach of speleothems fluorescence

    Science.gov (United States)

    Quiers, Marine; Perrette, Yves; Poulenard, Jérôme; Chalmin, Emilie; Revol, Morgane

    2014-05-01

    In this study, we propose a framework to interpret quantitatively the fluorescence of speleothems organic matter (OM) by the way of a bank of water-extracted organic matter. Due to its efficiency to described dissolved organic matter (DOM) characteritics, fluorescence has been used to determined DOM signatures in natural systems, water circulations, OM transfer from soils, OM evolution in soils or recently, DOM changes in engineered treatment systems. Fluorescence has also been used in speleothems studies, mainly as a growth indicator. Only few studies interpret it as an environmental proxy. Indeed, the fluorescence of OM provides information on the type of organic molecules trapped in speleothems and their evolutions. But the most direct information given by fluorescence is the variation of OM quantities. Actually, increase of fluorescence intensity is generally related to an increase in OM quantity but may also be induced by calcite optical effect or qualitative change of OM. However, analytical technics used in water environments cannot be used for speleothem samples. In this study we propose to give a frame to interpret quantitatively the fluorescence signal of speleothems. 3 different samples of stalagmites from french northern Prealps were used. To allow the quantification of the fluorescence signal, we need to measure the fluorescence and the quantity of organic matter on the same sample. OM of speleothems was extracted by an acid digestion method and analysed with a spectrofluorimeter. However, it was not possible to quantify directly the OM, as the extract solvant was a high-concentrated acid. To solve this problem, a calibration using soil extracts was realised. Soils were chosen in order to represent the diversity of OM present in the environment above the caves. Attention was focused on soil and vegetation types, and landuse. Organic material was water extracted from soils and its fluorescence was also measured. Total organic carbon was performed on the

  16. Protein recognition by a pattern-generating fluorescent molecular probe

    Science.gov (United States)

    Pode, Zohar; Peri-Naor, Ronny; Georgeson, Joseph M.; Ilani, Tal; Kiss, Vladimir; Unger, Tamar; Markus, Barak; Barr, Haim M.; Motiei, Leila; Margulies, David

    2017-12-01

    Fluorescent molecular probes have become valuable tools in protein research; however, the current methods for using these probes are less suitable for analysing specific populations of proteins in their native environment. In this study, we address this gap by developing a unimolecular fluorescent probe that combines the properties of small-molecule-based probes and cross-reactive sensor arrays (the so-called chemical 'noses/tongues'). On the one hand, the probe can detect different proteins by generating unique identification (ID) patterns, akin to cross-reactive arrays. On the other hand, its unimolecular scaffold and selective binding enable this ID-generating probe to identify combinations of specific protein families within complex mixtures and to discriminate among isoforms in living cells, where macroscopic arrays cannot access. The ability to recycle the molecular device and use it to track several binding interactions simultaneously further demonstrates how this approach could expand the fluorescent toolbox currently used to detect and image proteins.

  17. mKikGR, a monomeric photoswitchable fluorescent protein.

    Directory of Open Access Journals (Sweden)

    Satoshi Habuchi

    Full Text Available The recent demonstration and utilization of fluorescent proteins whose fluorescence can be switched on and off has greatly expanded the toolkit of molecular and cell biology. These photoswitchable proteins have facilitated the characterization of specifically tagged molecular species in the cell and have enabled fluorescence imaging of intracellular structures with a resolution far below the classical diffraction limit of light. Applications are limited, however, by the fast photobleaching, slow photoswitching, and oligomerization typical for photoswitchable proteins currently available. Here, we report the molecular cloning and spectroscopic characterization of mKikGR, a monomeric version of the previously reported KikGR that displays high photostability and switching rates. Furthermore, we present single-molecule imaging experiments that demonstrate that individual mKikGR proteins can be localized with a precision of better than 10 nanometers, suggesting their suitability for super-resolution imaging.

  18. Plasmonic band structure controls single-molecule fluorescence.

    Science.gov (United States)

    Langguth, Lutz; Punj, Deep; Wenger, Jérôme; Koenderink, A Femius

    2013-10-22

    Plasmonics and photonic crystals are two complementary approaches to tailor single-emitter fluorescence, using strong local field enhancements near metals on one hand and spatially extended photonic band structure effects on the other hand. Here, we explore the emergence of spontaneous emission control by finite-sized hexagonal arrays of nanoapertures milled in gold film. We demonstrate that already small lattices enable highly directional and enhanced emission from single fluorescent molecules in the central aperture. Even for clusters just four unit cells across, the directionality is set by the plasmonic crystal band structure, as confirmed by full-wave numerical simulations. This realization of plasmonic phase array antennas driven by single quantum emitters opens a flexible toolbox to engineer fluorescence and its detection.

  19. Fluorescent nucleobases as tools for studying DNA and RNA

    Science.gov (United States)

    Xu, Wang; Chan, Ke Min; Kool, Eric T.

    2017-11-01

    Understanding the diversity of dynamic structures and functions of DNA and RNA in biology requires tools that can selectively and intimately probe these biomolecules. Synthetic fluorescent nucleobases that can be incorporated into nucleic acids alongside their natural counterparts have emerged as a powerful class of molecular reporters of location and environment. They are enabling new basic insights into DNA and RNA, and are facilitating a broad range of new technologies with chemical, biological and biomedical applications. In this Review, we will present a brief history of the development of fluorescent nucleobases and explore their utility as tools for addressing questions in biophysics, biochemistry and biology of nucleic acids. We provide chemical insights into the two main classes of these compounds: canonical and non-canonical nucleobases. A point-by-point discussion of the advantages and disadvantages of both types of fluorescent nucleobases is made, along with a perspective into the future challenges and outlook for this burgeoning field.

  20. BIOCOMPATIBLE FLUORESCENT MICROSPHERES: SAFE PARTICLES FOR MATERIAL PENETRATION STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Farquar, G; Leif, R

    2009-07-15

    Biocompatible polymers with hydrolyzable chemical bonds have been used to produce safe, non-toxic fluorescent microspheres for material penetration studies. The selection of polymeric materials depends on both biocompatibility and processability, with tailored fluorescent properties depending on specific applications. Microspheres are composed of USFDA-approved biodegradable polymers and non-toxic fluorophores and are therefore suitable for tests where human exposure is possible. Micropheres were produced which contain unique fluorophores to enable discrimination from background aerosol particles. Characteristics that affect dispersion and adhesion can be modified depending on use. Several different microsphere preparation methods are possible, including the use of a vibrating orifice aerosol generator (VOAG), a Sono-Tek atomizer, an emulsion technique, and inkjet printhead. Applications for the fluorescent microspheres include challenges for biodefense system testing, calibrants for biofluorescence sensors, and particles for air dispersion model validation studies.

  1. Miniaturized integration of a fluorescence microscope

    Science.gov (United States)

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

    2013-01-01

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

  2. Miniaturized integration of a fluorescence microscope.

    Science.gov (United States)

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

    2011-09-11

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

  3. The Digital Thread as the Key Enabler

    Science.gov (United States)

    2016-11-01

    life cycle by providing the capability to access, integrate and transform disparate data into actionable information. The digital thread is the...17 Defense AT&L: November-December 2016 The Digital Thread as the Key Enabler Col. Keith Bearden, USAF Bearden is the deputy director of...enabling you to do your job better, faster and cheaper. There is one initiative, the key enabler, to accomplish this goal—the digital thread. But let’s

  4. Assessing Photosynthesis by Fluorescence Imaging

    Science.gov (United States)

    Saura, Pedro; Quiles, Maria Jose

    2011-01-01

    This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

  5. Visible fluorescent proteins for FRET

    NARCIS (Netherlands)

    Kremers, G.J.; Goedhart, J.; Gadella, T.W.J.

    2009-01-01

    This chapter discusses the use of Visible fluorescent proteins (VFPs) for FRET studies, a comprehensive table with Förster radii of VFP pairs is presented and recommendations for choosing the right pairs are made. The chapter discusses VFPs that are used for studies that use fluorescence resonance

  6. Fluorescent Proteins for Flow Cytometry.

    Science.gov (United States)

    Hawley, Teresa S; Hawley, Robert G; Telford, William G

    2017-04-03

    Fluorescent proteins have become standard tools for cell and molecular biologists. The color palette of fluorescent proteins spans the ultraviolet, visible, and near-infrared spectrum. Utility of fluorescent proteins has been greatly facilitated by the availability of compact and affordable solid state lasers capable of providing various excitation wavelengths. In theory, the plethora of fluorescent proteins and lasers make it easy to detect multiple fluorescent proteins simultaneously. However, in practice, heavy spectral overlap due to broad excitation and emission spectra presents a challenge. In conventional flow cytometry, careful selection of excitation wavelengths and detection filters is necessary. Spectral flow cytometry, an emerging methodology that is not confined by the "one color, one detector" paradigm, shows promise in the facile detection of multiple fluorescent proteins. This chapter provides a synopsis of fluorescent protein development, a list of commonly used fluorescent proteins, some practical considerations and strategies for detection, and examples of applications. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  7. Fluorescence Spectra of Highlighter Inks

    Science.gov (United States)

    Birriel, Jennifer J.; King, Damon

    2018-01-01

    Fluorescence spectra excited by laser pointers have been the subject of several papers in "TPT". These papers all describe a fluorescence phenomenon in which the reflected laser light undergoes a change in color: this color change results from the combination of some partially reflected laser light and additional colors generated by…

  8. Semantic Sensor Web Enablement for COAST Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sensor Web Enablement (SWE) is an Open Geospatial Consortium (OGC) standard Service Oriented Architecture (SOA) that facilitates discovery and integration of...

  9. Rapid assessment of different oxygenic phototrophs and single-cell photosynthesis with multicolour variable chlorophyll fluorescence imaging

    DEFF Research Database (Denmark)

    Trampe, Erik Christian Løvbjerg; Kolbowski, J.; Schreiber, U.

    2011-01-01

    , red or white light. Automated sequential exposure of microscopic samples to the three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms......We present a new system for microscopic multicolour variable chlorophyll fluorescence imaging of aquatic phototrophs. The system is compact and portable and enables microscopic imaging of photosynthetic performance of individual cells and chloroplasts using different combinations of blue, green...

  10. Single-molecule fluorescence microscopy review: shedding new light on old problems.

    Science.gov (United States)

    Shashkova, Sviatlana; Leake, Mark C

    2017-08-31

    Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called 'green revolution', has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called 'super-resolution' fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques. © 2017 The Author(s).

  11. Microscope enabling multimodality imaging, angle-resolved scattering, and scattering spectroscopy.

    Science.gov (United States)

    Cottrell, W J; Wilson, J D; Foster, T H

    2007-08-15

    We present the design, construction, and initial characterization of a multifunctional imaging/scattering spectroscopy system built around a commercial inverted microscope platform. The system enables co-registered brightfield, Fourier-filtered darkfield, and fluorescence imaging; monochromatic angle-resolved scattering measurements; and white-light wavelength-resolved scattering spectroscopy from the same field of view. A fiber-based illumination system provides illumination-wavelength flexibility and a good approximation to a point source. The performance of the system in its various data acquisition modes is experimentally verified using fluorescent microspheres. This multifunctional instrument provides a platform for studies on adherent cells from which the biophysical implications of subcellular light scattering can be studied in conjunction with sensitive fluorescence-based techniques.

  12. Fluorescence calibration method for single-particle aerosol fluorescence instruments

    Science.gov (United States)

    Shipley Robinson, Ellis; Gao, Ru-Shan; Schwarz, Joshua P.; Fahey, David W.; Perring, Anne E.

    2017-05-01

    Real-time, single-particle fluorescence instruments used to detect atmospheric bioaerosol particles are increasingly common, yet no standard fluorescence calibration method exists for this technique. This gap limits the utility of these instruments as quantitative tools and complicates comparisons between different measurement campaigns. To address this need, we have developed a method to produce size-selected particles with a known mass of fluorophore, which we use to calibrate the fluorescence detection of a Wideband Integrated Bioaerosol Sensor (WIBS-4A). We use mixed tryptophan-ammonium sulfate particles to calibrate one detector (FL1; excitation = 280 nm, emission = 310-400 nm) and pure quinine particles to calibrate the other (FL2; excitation = 280 nm, emission = 420-650 nm). The relationship between fluorescence and mass for the mixed tryptophan-ammonium sulfate particles is linear, while that for the pure quinine particles is nonlinear, likely indicating that not all of the quinine mass contributes to the observed fluorescence. Nonetheless, both materials produce a repeatable response between observed fluorescence and particle mass. This procedure allows users to set the detector gains to achieve a known absolute response, calculate the limits of detection for a given instrument, improve the repeatability of the instrumental setup, and facilitate intercomparisons between different instruments. We recommend calibration of single-particle fluorescence instruments using these methods.

  13. Enabling Routes as Context in Mobile Services

    DEFF Research Database (Denmark)

    Brilingaite, Agne; Jensen, Christian Søndergaard; Zokaite, Nora

    2004-01-01

    With the continuing advances in wireless communications, geo-positioning, and portable electronics, an infrastructure is emerging that enables the delivery of on-line, location-enabled services to very large numbers of mobile users. A typical usage situation for mobile services is one characterized...

  14. Enabling Routes as Context in Mobile Services

    DEFF Research Database (Denmark)

    Brilingaite, Agne; Jensen, Christian Søndergaard; Zokaite, Nora

    With the continuing advances in wireless communications, geo-positioning, and portable electronics, an infrastructure is emerging that enables the delivery of on-line, location-enabled services to very large numbers of mobile users. A typical usage situation for mobile services is one characterized...

  15. Single Molecule Spectroscopy of Fluorescent Proteins

    NARCIS (Netherlands)

    Blum, Christian; Subramaniam, Vinod

    2009-01-01

    The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject to intense research. Understanding the

  16. Single-molecule spectroscopy of fluorescent proteins

    NARCIS (Netherlands)

    Blum, Christian; Subramaniam, Vinod

    The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject to intense research. Understanding the

  17. Novel fluorescent dyes for single DNA molecule techniques.

    Science.gov (United States)

    Zarkov, Alexander; Vasilev, Aleksey; Deligeorgiev, Todor; Stoynov, Stoyno; Nedelcheva-Veleva, Marina

    2013-01-01

    To answer the demands of scientific and medical imaging issues, the family of nucleic acid fluorescent dyes is constantly enlarging. Most of the developed dyes reveal high qualities in bulk solution assays but are inefficient to produce a strong and sufficiently stable signal to enable the application of single-molecule techniques. Therefore, we tested 12 novel monomeric and homodimeric cyanine dyes for potential single DNA molecule imaging. Although their qualities in bulk solutions have already been described, nothing was known about their behavior on a single-molecule level. All 12 dyes demonstrated strong emission when intercalated into single DNA molecules and stretched on a silanized surface, which makes them the perfect choice for fluorescent microscopy imaging. A comparison of their fluorescence intensity and photostability with the most applicable dyes in single-molecule techniques, fluorescent dyes YOYO-1 and POPO-3, was carried out. They all exhibited a strong signal, comparable to that of YOYO-1. However, in contrast to YOYO-1, which is visualized under a green filter only, their emission permits red filter visualization. As their photostability highly exceeds that of similar spectrum POPO-3 dye, the studied dyes stand out as the best choice for a broad range of solid surface single-molecule applications when yellow to red DNA backbone fluorescence is needed.

  18. Novel Fluorescent Dyes for Single DNA Molecule Techniques

    Directory of Open Access Journals (Sweden)

    Alexander Zarkov

    2013-03-01

    Full Text Available To answer the demands of scientific and medical imaging issues, the family of nucleic acid fluorescent dyes is constantly enlarging. Most of the developed dyes reveal high qualities in bulk solution assays but are inefficient to produce a strong and sufficiently stable signal to enable the application of single-molecule techniques. Therefore, we tested 12 novel monomeric and homodimeric cyanine dyes for potential single DNA molecule imaging. Although their qualities in bulk solutions have already been described, nothing was known about their behavior on a single-molecule level. All 12 dyes demonstrated strong emission when intercalated into single DNA molecules and stretched on a silanized surface, which makes them the perfect choice for fluorescent microscopy imaging. A comparison of their fluorescence intensity and photostability with the most applicable dyes in single-molecule techniques, fluorescent dyes YOYO-1 and POPO-3, was carried out. They all exhibited a strong signal, comparable to that of YOYO-1. However, in contrast to YOYO-1, which is visualized under a green filter only, their emission permits red filter visualization. As their photostability highly exceeds that of similar spectrum POPO-3 dye, the studied dyes stand out as the best choice for a broad range of solid surface single-molecule applications when yellow to red DNA backbone fluorescence is needed.

  19. Integrated liquid jet waveguide for fluorescence spectroscopy on chip

    Science.gov (United States)

    Persichetti, Gianluca; Testa, Genni; Bernini, Romeo

    2013-03-01

    An optofluidic jet waveguide for on chip fluorescence analysis is presented. The waveguide consists of an high speed water jet produced by means of a micro-channel coupled with a multimode optical fiber collecting the fluorescence opportunely excited. The liquid jet acts, at the same time, as the solution to analyse and as an optical waveguide. This configuration allows a strong reduction of the scattering and fluorescence of non analyte substances enabling a very low limit of detection (LOD). The integrated device is fabricated by PMMA micro-machining allowing a self-alignment between the liquid jet waveguide and the optical fiber used to deliver the fluorescence to the detector. The performance of the system has been tested on Cy5 water solutions and LOD of 2.56 nM has been obtained. A proof-of-concept of filter-free measurements has been performed demonstrating that fluorescence measurements can be performed also by using a photodiode with an LOD of 6.11 nM.

  20. ENGINEERED FLUORESCENT PROTEINS ILLUMINATE THE BACTERIAL PERIPLASM

    Directory of Open Access Journals (Sweden)

    Thorben Dammeyer

    2012-10-01

    Full Text Available The bacterial periplasm is of special interest whenever cell factories are designed and engineered. Recombinantely produced proteins are targeted to the periplasmic space of Gram negative bacteria to take advantage of the authentic N-termini, disulfide bridge formation and easy accessibility for purification with less contaminating cellular proteins. The oxidizing environment of the periplasm promotes disulfide bridge formation – a prerequisite for proper folding of many proteins into their active conformation. In contrast, the most popular reporter protein in all of cell biology, Green Fluorescent Protein (GFP, remains inactive if translocated to the periplasmic space prior to folding. Here, the self-catalyzed chromophore maturation is blocked by formation of covalent oligomers via interchain disulfide bonds in the oxidizing environment. However, different protein engineering approaches addressing folding and stability of GFP resulted in improved proteins with enhanced folding properties. Recent studies describe GFP variants that are not only active if translocated in their folded form via the twin-arginine translocation (Tat pathway, but actively fold in the periplasm following general secretory pathway (Sec and signal recognition particle (SRP mediated secretion. This mini-review highlights the progress that enables new insights into bacterial export and periplasmic protein organization, as well as new biotechnological applications combining the advantages of the periplasmic production and the Aequorea-based fluorescent reporter proteins.

  1. Engineered fluorescent proteins illuminate the bacterial periplasm

    Directory of Open Access Journals (Sweden)

    Thorben Dammeyer

    2012-10-01

    Full Text Available The bacterial periplasm is of special interest whenever cell factories are designed and engineered. Recombinantely produced proteins are targeted to the periplasmic space of Gram negative bacteria to take advantage of the authentic N-termini, disulfide bridge formation and easy accessibility for purification with less contaminating cellular proteins. The oxidizing environment of the periplasm promotes disulfide bridge formation - a prerequisite for proper folding of many proteins into their active conformation. In contrast, the most popular reporter protein in all of cell biology, Green Fluorescent Protein (GFP, remains inactive if translocated to the periplasmic space prior to folding. Here, the self-catalyzed chromophore maturation is blocked by formation of covalent oligomers via interchain disulfide bonds in the oxidizing environment. However, different protein engineering approaches addressing folding and stability of GFP resulted in improved proteins with enhanced folding properties. Recent studies describe GFP variants that are not only active if translocated in their folded form via the twin-arginine translocation (Tat pathway, but actively fold in the periplasm following general secretory pathway (Sec and signal recognition particle (SRP mediated secretion. This mini-review highlights the progress that enables new insights into bacterial export and periplasmic protein organization, as well as new biotechnological applications combining the advantages of the periplasmic production and the Aequorea-based fluorescent reporter proteins.

  2. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Alok M. Srivastava

    2005-09-30

    This is the Yearly Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. Our chief achievement, during the current contract period, pertains to the successful synthesis and characterization of coated phosphors. We demonstrated several synthesis techniques for the coating of micron sized commercial phosphors with quantum-splitting and UV emitting nanophosphors. We have also continued our fundamental investigations into the physical processes that determine the quantum efficiency of the nanophosphors and this has further helped codify a set of rules for the host lattice that support efficient quantum splitting and UV emission at room temperature. In this report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.

  3. Diffuse fluorescence tomography of exo- and endogenously labeled tumors

    Science.gov (United States)

    Balalaeva, Irina V.; Turchin, Ilya V.; Orlova, Anna G.; Plekhanov, Vladimir I.; Shirmanova, Marina V.; Kleshnin, Michail S.; Fiks, Ilya I.; Zagainova, Elena V.; Kamensky, Vladislav A.

    2007-06-01

    Strong light scattering and absorption limit observation of the internal structure of biological tissue. Only special tools for turbid media imaging, such as optical diffuse tomography, enable noninvasive investigation of the internal biological tissues, including visualization and intravital monitoring of deep tumors. In this work the preliminary results of diffuse fluorescence tomography (DFT) of small animals are presented. Usage of exogenous fluorophores, targeted specifically at tumor cells, and fluorescent proteins expressed endogenously can significantly increase the contrast of obtained images. Fluorescent compounds of different nature, such as sulphonated aluminium phthalocyanine (Photosens), red fluorescing proteins and CdTe/CdSe-core/shell nanocrystals (quantum dots) were applied. We tested diffuse fluorescence tomography method at model media, in post mortem and in vivo experiments. The animal was scanned in transilluminative configuration by low-frequency modulated light (1 kHz) from Nd:YAG laser with second harmonic generation at wavelength of 532 nm or semiconductor laser at wavelength of 655 nm. Quantum dots or protein DsRed2 in glass capsules (inner diameter 2-3 mm) were placed post mortem inside the esophagus of 7-day-old hairless rats to simulate marked tumors. Photosens was injected intravenously to linear mice with metastazing Lewis lung carcinoma. The reconstruction algorithm, based on Algebraic Reconstruction Technique, was created and tested numerically in model experiments. High contrast images of tumor simulating capsules with DsRed2 concentrations about 10 -6 M and quantum dots about 5x10 -11 M have been obtained. Organ distribution of Photosens and its accumulation in tumors and surrounding tissues of animals has been examined. We have conducted the monitoring of tumors, exogenously labeled by photosensitizer. This work demonstrates potential capabilities of DFT method for intravital detection and monitoring of deep fluorescent

  4. Hyperspectral fluorescence imaging with multi wavelength LED excitation

    Science.gov (United States)

    Luthman, A. Siri; Dumitru, Sebastian; Quirós-Gonzalez, Isabel; Bohndiek, Sarah E.

    2016-04-01

    Hyperspectral imaging (HSI) can combine morphological and molecular information, yielding potential for real-time and high throughput multiplexed fluorescent contrast agent imaging. Multiplexed readout from targets, such as cell surface receptors overexpressed in cancer cells, could improve both sensitivity and specificity of tumor identification. There remains, however, a need for compact and cost effective implementations of the technology. We have implemented a low-cost wide-field multiplexed fluorescence imaging system, which combines LED excitation at 590, 655 and 740 nm with a compact commercial solid state HSI system operating in the range 600 - 1000 nm. A key challenge for using reflectance-based HSI is the separation of contrast agent fluorescence from the reflectance of the excitation light. Here, we illustrate how it is possible to address this challenge in software, using two offline reflectance removal methods, prior to least-squares spectral unmixing. We made a quantitative comparison of the methods using data acquired from dilutions of contrast agents prepared in well-plates. We then established the capability of our HSI system for non-invasive in vivo fluorescence imaging in small animals using the optimal reflectance removal method. The HSI presented here enables quantitative unmixing of at least four fluorescent contrast agents (Alexa Fluor 610, 647, 700 and 750) simultaneously in living mice. A successful unmixing of the four fluorescent contrast agents was possible both using the pure contrast agents and with mixtures. The system could in principle also be applied to imaging of ex vivo tissue or intraoperative imaging in a clinical setting. These data suggest a promising approach for developing clinical applications of HSI based on multiplexed fluorescence contrast agent imaging.

  5. Fluorescent in situ hybridization employing the conventional NBT/BCIP chromogenic stain.

    Science.gov (United States)

    Trinh, Le A; McCutchen, Marshall D; Bonner-Fraser, Marianne; Fraser, Scott E; Bumm, Lloyd A; McCauley, David W

    2007-06-01

    In situ hybridization techniques typically employ chromogenic staining by enzymatic amplification to detect domains of gene expression. We demonstrate the previously unreported near infrared (NIR) fluorescence of the dark purple stain formed from the commonly used chromogens, nitro blue tetrazolium (NBT) and 5-bromo-4-chloro-3-indolyl phosphate (BCIP). The solid reaction product has significant fluorescence that enables the use of confocal microscopy to generate high-resolution three-dimensional (3-D) imaging of gene expression.

  6. Two-color RESOLFT nanoscopy with green and red fluorescent photochromic proteins.

    OpenAIRE

    Lavoie-Cardinal, Flavie; Jensen, Nickels A.; Westphal, Volker; Stiel, Andre C.; Chmyrov, Andriy; Bierwagen, Jakob; Testa, Ilaria; Jakobs, Stefan; Hell, Stefan W.

    2014-01-01

    Up to now, all demonstrations of reversible saturable optical fluorescence transitions (RESOLFT) superresolution microscopy of living cells have relied on the use of reversibly switchable fluorescent proteins (RSFP) emitting in the green spectral range. Here we show RESOLFT imaging with rsCherryRev1.4, a new red-emitting RSFP enabling a spatial resolution up to four times higher than the diffraction barrier. By co-expressing green and red RSFPs in living cells we demonstrate two-color RESOLFT...

  7. Fluorescence-Lifetime Imaging Microscopy for Visualization of Quantum Dots’ Endocytic Pathway

    Directory of Open Access Journals (Sweden)

    Leona Damalakiene

    2016-03-01

    Full Text Available Accumulation of carboxylated polyethylene glycol (PEG CdSe/ZnSquantum dots (QDs has been monitored in living fibroblasts using confocal microscopy for fluorescence intensity and fluorescence-lifetime imaging (FLIM. The wide range of mean photoluminescence (PL lifetime values was observed for the intracellular QDs in different intracellular microenvironment, which revealed structural heterogeneity of endosomes and enabled the distinguishing among endosomes of different maturity.

  8. High-precision correlative fluorescence and electron cryo microscopy using two independent alignment markers ☆

    OpenAIRE

    Schellenberger, Pascale; Kaufmann, Rainer; Siebert, C. Alistair; Hagen, Christoph; Wodrich, Harald; Grünewald, Kay

    2014-01-01

    Correlative light and electron microscopy (CLEM) is an emerging technique which combines functional information provided by fluorescence microscopy (FM) with the high-resolution structural information of electron microscopy (EM). So far, correlative cryo microscopy of frozen-hydrated samples has not reached better than micrometre range accuracy. Here, a method is presented that enables the correlation between fluorescently tagged proteins and electron cryo tomography (cryoET) data with nanome...

  9. Array-based sensing of normal, cancerous, and metastatic cells using conjugated fluorescent polymers.

    Science.gov (United States)

    Bajaj, Avinash; Miranda, Oscar R; Phillips, Ronnie; Kim, Ik-Bum; Jerry, D Joseph; Bunz, Uwe H F; Rotello, Vincent M

    2010-01-27

    A family of conjugated fluorescent polymers was used to create an array for cell sensing. Fluorescent conjugated polymers with pendant charged residues provided multivalent interactions with cell membranes, allowing the detection of subtle differences between different cell types on the basis of cell surface features. Highly reproducible characteristic patterns were obtained from different cell types as well as from isogenic cell lines, enabling the identification of the cell type as well differentiating between normal, cancerous, and metastatic isogenic cell types with high accuracy.

  10. A Combined Light Sheet Fluorescence and Differential Interference Contrast Microscope for Live Imaging of Multicellular Specimens

    Science.gov (United States)

    Baker, Ryan; Taormina, Michael; Jemielita, Matthew; Parthasarathy, Raghuveer

    2015-03-01

    We present a microscope capable of both light sheet fluorescence microscopy (LSFM) and differential interference contrast microscopy (DICM). The two imaging modes, which to the best of our knowledge have not previously been combined, are complementary: LSFM provides high speed three-dimensional imaging of fluorescently labeled components of multicellular systems, large fields of view, and low phototoxicity, while DICM reveals the unlabeled neighborhood of tissues, organs, and other structures with high contrast and inherent optical sectioning. Use of a shared detection path for both imaging modes enables simple integration of the two techniques in one microscope. To demonstrate the instrument's utility, we provide several examples which focus on the digestive tract of the larval zebrafish. We show that DICM can sometimes circumvent the need for fluorescent based techniques, augmenting the number of parameters obtainable per experiment when used alongside LSFM, and that DICM can be used to augment each experiment by imaging complementary features, such as non-fluorescent local environments near fluorescent samples (e.g. fluorescent enteric neurons imaged alongside the non-fluorescent gut wall), interactions between fluorescent and non-fluorescent samples (e.g. bacteria), and more. NSF Award 0922951, NIH Award 1P50 GM098911

  11. Confocal microscopy for the histological fluorescence pattern of a recurrent atypical meningioma: case report.

    Science.gov (United States)

    Whitson, Wesley J; Valdes, Pablo A; Harris, Brent T; Paulsen, Keith D; Roberts, David W

    2011-06-01

    Fluorescence-guided resection with 5-aminolevulinic acid (5-ALA), which has shown promising results in the resection of malignant gliomas, has been used for meningioma resection in an attempt to more clearly delineate the tumor margin. However, no article has investigated the fluorescence pattern of meningiomas on a histological level. Understanding the microscopic pattern of fluorescence could help assess the precision and utility of using 5-ALA for these tumors. We present the case of a recurrent atypical meningioma operated on with 5-ALA fluorescence-guided resection for delineation of tumor tissue from surrounding uninvolved dura. A 53-year-old woman presented with recurrent atypical meningioma of the falx. Prior treatment included surgical resection 6 years earlier with subsequent fractionated radiation therapy and radiosurgery for tumor progression. The patient was given 5-ALA 20 mg/kg body weight dissolved in 100 mL water 3 hours before induction of anesthesia. Intraoperative fluorescence was coregistered with preoperative imaging. Neuropathological analysis of the resected falx with confocal microscopy enabled correlation of fluorescence with the extent of tumor on a histological level. Fluorescence guidance allowed clear intraoperative delineation of tumor tissue from adjacent, uninvolved dura. On a microscopic level, there was a very close correlation of fluorescence with tumor, but some tumor cells did not fluoresce. Copyright © 2011 by the Congress of Neurological Surgeons

  12. Highly Efficient Soluble Blue Delayed Fluorescent and Hyperfluorescent Organic Light-Emitting Diodes by Host Engineering.

    Science.gov (United States)

    Jeon, Sang Kyu; Park, Hee-Jun; Lee, Jun Yeob

    2018-01-30

    Solution-processed high-efficiency fluorescent organic light-emitting diodes with an external quantum efficiency over 18% were developed by engineering a host material and device structure designed for solution process. A high triplet energy host material designed for the solution process, (oxybis(3-(tert-butyl)-6,1-phenylene))bis(diphenylphosphine oxide) (DPOBBPE), worked efficiently as the host of blue fluorescent devices because of good solubility, high photoluminescence quantum yield, and good film properties. The DPOBBPE host enabled a high external quantum efficiency of 18.8% in the fluorescent organic light-emitting diodes by the solution process. Moreover, 25.8% external quantum efficiency in the soluble blue thermally activated delayed fluorescent devices was also realized. The 25.8% external quantum efficiency of the DPOBBPE delayed fluorescent device and 18.8% external quantum efficiency of the fluorescent device are the highest efficiency values achieved in the solution-processed blue fluorescent organic light-emitting diodes. Moreover, the solution-processed fluorescent device showed an improved blue color coordinate of (0.14, 0.20) compared to (0.17, 0.31) of the delayed fluorescent device.

  13. Fluorescence lifetime imaging microscopy (FLIM).

    NARCIS (Netherlands)

    van Munster, E.B.; Gadella, Th.W.J.; Rietdorf, J.

    2005-01-01

    Fluorescence lifetime imaging microscopy (FLIM) is a technique to map the spatial distribution of nanosecond excited state lifetimes within microscopic images. FLIM systems have been implemented both in the frequency domain, using sinusoidally intensity-modulated excitation light and modulated

  14. Advanced Methods in Fluorescence Microscopy

    Directory of Open Access Journals (Sweden)

    Luke Fritzky

    2013-01-01

    Full Text Available It requires a good deal of will power to resist hyperbole in considering the advances that have been achieved in fluorescence microscopy in the last 25 years. Our effort has been to survey the modalities of microscopic fluorescence imaging available to cell biologists and perhaps useful for diagnostic pathologists. The gamut extends from established confocal laser scanning through multiphoton and TIRF to the emerging technologies of super-resolution microscopy that breech the Abbé limit of resolution. Also considered are the recent innovations in structured and light sheet illumination, the use of FRET and molecular beacons that exploit specific characteristics of designer fluorescent proteins, fluorescence speckles, and second harmonic generation for native anisometric structures like collagen, microtubules and sarcomeres.

  15. Genetically Encoded Fluorescent Redox Probes

    OpenAIRE

    Hui-Wang Ai; Wei Ren

    2013-01-01

    Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, adv...

  16. Fluorescence axial nanotomography with plasmonics.

    Science.gov (United States)

    Cade, Nicholas I; Fruhwirth, Gilbert O; Krasavin, Alexey V; Ng, Tony; Richards, David

    2015-01-01

    We present a novel imaging technique with super-resolution axial sensitivity, exploiting the changes in fluorescence lifetime above a plasmonic substrate. Using conventional confocal fluorescence lifetime imaging, we show that it is possible to deliver down to 6 nm axial position sensitivity of fluorophores in whole biological cell imaging. We employ this technique to map the topography of the cellular membrane, and demonstrate its application in an investigation of receptor-mediated endocytosis in carcinoma cells.

  17. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  18. Light Sheet Fluorescence Microscopy (LSFM)

    OpenAIRE

    Adams, Michael W.; Loftus, Andrew F.; Dunn, Sarah E.; Joens, Matthew S.; Fitzpatrick, James A. J.

    2015-01-01

    The development of confocal microscopy techniques introduced the ability to optically section fluorescent samples in the axial dimension, perpendicular to the image plane. These approaches, via the placement of a pinhole in the conjugate image plane, provided superior resolution in the axial (z) dimension resulting in nearly isotropic optical sections. However, increased axial resolution, via pinhole optics, comes at the cost of both speed and excitation efficiency. Light Sheet Fluorescent Mi...

  19. Towards sensitive, high-throughput, biomolecular assays based on fluorescence lifetime

    Science.gov (United States)

    Ioanna Skilitsi, Anastasia; Turko, Timothé; Cianfarani, Damien; Barre, Sophie; Uhring, Wilfried; Hassiepen, Ulrich; Léonard, Jérémie

    2017-09-01

    Time-resolved fluorescence detection for robust sensing of biomolecular interactions is developed by implementing time-correlated single photon counting in high-throughput conditions. Droplet microfluidics is used as a promising platform for the very fast handling of low-volume samples. We illustrate the potential of this very sensitive and cost-effective technology in the context of an enzymatic activity assay based on fluorescently-labeled biomolecules. Fluorescence lifetime detection by time-correlated single photon counting is shown to enable reliable discrimination between positive and negative control samples at a throughput as high as several hundred samples per second.

  20. CMOS Time-Resolved, Contact, and Multispectral Fluorescence Imaging for DNA Molecular Diagnostics

    Directory of Open Access Journals (Sweden)

    Nan Guo

    2014-10-01

    Full Text Available Instrumental limitations such as bulkiness and high cost prevent the fluorescence technique from becoming ubiquitous for point-of-care deoxyribonucleic acid (DNA detection and other in-field molecular diagnostics applications. The complimentary metal-oxide-semiconductor (CMOS technology, as benefited from process scaling, provides several advanced capabilities such as high integration density, high-resolution signal processing, and low power consumption, enabling sensitive, integrated, and low-cost fluorescence analytical platforms. In this paper, CMOS time-resolved, contact, and multispectral imaging are reviewed. Recently reported CMOS fluorescence analysis microsystem prototypes are surveyed to highlight the present state of the art.

  1. Electrophoresis microchip with integrated waveguides for simultaneous native UV fluorescence and absorbance detection

    DEFF Research Database (Denmark)

    Ohlsson, Pelle Daniel; Sala, Olga Ordeig; Mogensen, Klaus Bo

    2009-01-01

    lid and by choosing a PMT insensitive to the excitation light. This way, the need for a fluorescence filter is eliminated. Calibration curves were measured for serotonin, tryptophan, propranolol and acetaminophen, and separations of the four compounds were demonstrated by electrophoresis and MEKC. All...... compounds could be detected in the micromolar range by absorbance detection, but fluorescence detection improved detection limits for compounds displaying native UV fluorescence up to ten times. The simultaneous detection also proved useful for the identification of compounds with similar retention times...... and even enables accurate quantification of co-eluting compounds....

  2. Fluorescence detection of serum albumin with a turnover-based sensor utilizing Kemp elimination reaction.

    Science.gov (United States)

    Sakamoto, Shingo; Komatsu, Toru; Ueno, Tasuku; Hanaoka, Kenjiro; Urano, Yasuteru

    2017-08-01

    The Kemp elimination reaction is a well-known chemical reaction that is facilitated on a protein surface microenvironment, and in particular is highly accelerated in a unique binding pocket of serum albumin. We have designed and synthesized a fluorescently activatable coumarin derivative with a benzisoxazole scaffold to enable monitoring of the Kemp elimination reaction in terms of fluorescence change for the first time. We show that this fluorescent sensor can sensitively and selectively quantitate serum albumin in blood samples. It also works in a dry-chemistry format. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. In Vivo Imaging of Far-red Fluorescent Proteins after DNA Electrotransfer to Muscle Tissue

    DEFF Research Database (Denmark)

    Hojman, Pernille; Eriksen, Jens; Gehl, Julie

    2009-01-01

    DNA electrotransfer to muscle tissue yields long-term, high levels of gene expression; showing great promise for future gene therapy. We want to characterize the novel far-red fluorescent protein Katushka as a marker for gene expression using time domain fluorescence in vivo imaging. Highly effic...... weeks. Depth and 3D analysis proved that the expression was located in the target muscle. In vivo bio-imaging using the novel Katushka fluorescent protein enables excellent evaluation of the transfection efficacy, and spatial distribution, but lacks long-term stability....

  4. Enabling Technology for Small Satellite Launch Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Access to space for Small Satellites is enabled by the use of excess launch capacity on existing launch vehicles. A range of sizes, form factors and masses need to...

  5. Enabling Technology for Small Satellite Launch Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Access to space for Small Satellites is enabled by the use of excess launch capacity on existing launch vehicles. A range of sizes, form factors and masses of small...

  6. Integrated Photonics Enabled by Slow Light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Chen, Yuntian; Ek, Sara

    2012-01-01

    In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources....

  7. Utility Energy Services Contracts: Enabling Documents

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-05-01

    Utility Energy Services Contracts: Enabling Documents provides materials that clarify the authority for Federal agencies to enter into utility energy services contracts (UESCs), as well as sample documents and resources to ease utility partnership contracting.

  8. Web Enabled DROLS Verity TopicSets

    National Research Council Canada - National Science Library

    Tong, Richard

    1999-01-01

    The focus of this effort has been the design and development of automatically generated TopicSets and HTML pages that provide the basis of the required search and browsing capability for DTIC's Web Enabled DROLS System...

  9. Optical Coherent Receiver Enables THz Wireless Bridge

    DEFF Research Database (Denmark)

    Yu, Xianbin; Liu, Kexin; Zhang, Hangkai

    2016-01-01

    We experimentally demonstrated a 45 Gbit/s 400 GHz photonic wireless communication system enabled by an optical coherent receiver, which has a high potential in fast recovery of high data rate connections, for example, in disaster....

  10. Utility Energy Services Contracts: Enabling Documents

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Karen; Vasquez, Deb

    2017-01-01

    The Federal Energy Management Program's 'Utility Energy Service Contracts: Enabling Documents' provide legislative information and materials that clarify the authority for federal agencies to enter into utility energy service contracts, or UESCs.

  11. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Alok Srivatava

    2007-03-31

    This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation

  12. Paradoxical Leadership to Enable Strategic Agility

    OpenAIRE

    Lewis, M. W.; Andriopoulos, C.; Smith, W. K.

    2014-01-01

    Strategic agility evokes contradictions, such as stability-flexibility, commitment-change, and established routines-novel approaches. These competing demands pose challenges that require paradoxical leadership—practices seeking creative, both/and solutions that can enable fast-paced, adaptable decision making. Why is managing paradox critical to strategic agility? And which practices enable leaders to effectively manage tensions? This article describes the paradoxical nature of strategic agil...

  13. ISS - Enabling Exploration Through Docking Standards

    Science.gov (United States)

    Hatfield, Caris A.

    2011-01-01

    NASA and the ISS partnership are jointly developing a key standard to enable future collaborative exploration. The IDSS is based on flight proven design while incorporating new low impact technology. Low impact technology accommodates a wide range of vehicle contact and capture conditions. This standard will get early demonstration on the ISS. Experience gained here will enable operational experience and the opportunity to refine the standard.

  14. Dynamics-Enabled Nanoelectromechanical Systems (NEMS) Oscillators

    Science.gov (United States)

    2014-06-01

    AFRL-RY-WP-TR-2014-0144 DYNAMICS-ENABLED NANOELECTROMECHANICAL SYSTEMS ( NEMS ) OSCILLATORS Michael Roukes California Institute...SYSTEMS ( NEMS ) OSCILLATORS 5a. CONTRACT NUMBER FA8650-10-1-7029 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61101E 6. AUTHOR(S) Michael Roukes...engineer, and demonstrate nonlinear-dynamics-enabled nanoelectromechanical system ( NEMS ) frequency-source technology. 15. SUBJECT TERMS

  15. Enabling Sustainable NESHAP Compliance for Army Installations

    Science.gov (United States)

    2009-05-07

    including the Chemical Agent Resistant Coating (CARC) system  Solvents, thinners and cleaners  Depainting materials (a.k.a., paint strippers ...or work practice standards UNCLASSIFIED UNCLASSIFIED Enabling DLSME NESHAP Compliance: Methylene Chloride (MeCl) Depainting (1) What we are doing...50% growth cap for large vats; usage cap outside of vats UNCLASSIFIED UNCLASSIFIED Enabling DLSME NESHAP Compliance: Methylene Chloride (MeCl

  16. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials.

    Science.gov (United States)

    Zhang, Yi; Yang, Jian

    2013-01-14

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology.

  17. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    OpenAIRE

    Zhang, Yi; Yang, Jian

    2012-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function ...

  18. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    Science.gov (United States)

    Zhang, Yi; Yang, Jian

    2013-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology. PMID:23710326

  19. Fluorescent retroreflective signing of work zones : abstract

    NARCIS (Netherlands)

    Vos, A.P. de; Horst, A.R.A. van der; Alferdinck, J.W.A.M.; Kooi, F.L.

    1999-01-01

    Fluorescent retroreflective materials increase the brightness of traffic signs. In construction work zones a benefit is expected from the increased conspicuity of fluorescent retroreflective signs. Fluorescent material can be used instead of non-fluorescent materials both for the advance warning

  20. 21 CFR 892.1220 - Fluorescent scanner.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fluorescent scanner. 892.1220 Section 892.1220...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1220 Fluorescent scanner. (a) Identification. A fluorescent scanner is a device intended to measure the induced fluorescent radiation in the body by exposing...

  1. Experimental design and quality assurance: in situ fluorescence instrumentation

    Science.gov (United States)

    Conmy, Robyn N.; Del Castillo, Carlos E.; Downing, Bryan D.; Chen, Robert F.

    2014-01-01

    Both instrument design and capabilities of fluorescence spectroscopy have greatly advanced over the last several decades. Advancements include solid-state excitation sources, integration of fiber optic technology, highly sensitive multichannel detectors, rapid-scan monochromators, sensitive spectral correction techniques, and improve data manipulation software (Christian et al., 1981, Lochmuller and Saavedra, 1986; Cabniss and Shuman, 1987; Lakowicz, 2006; Hudson et al., 2007). The cumulative effect of these improvements have pushed the limits and expanded the application of fluorescence techniques to numerous scientific research fields. One of the more powerful advancements is the ability to obtain in situ fluorescence measurements of natural waters (Moore, 1994). The development of submersible fluorescence instruments has been made possible by component miniaturization and power reduction including advances in light sources technologies (light-emitting diodes, xenon lamps, ultraviolet [UV] lasers) and the compatible integration of new optical instruments with various sampling platforms (Twardowski et at., 2005 and references therein). The development of robust field sensors skirt the need for cumbersome and or time-consuming filtration techniques, the potential artifacts associated with sample storage, and coarse sampling designs by increasing spatiotemporal resolution (Chen, 1999; Robinson and Glenn, 1999). The ability to obtain rapid, high-quality, highly sensitive measurements over steep gradients has revolutionized investigations of dissolved organic matter (DOM) optical properties, thereby enabling researchers to address novel biogeochemical questions regarding colored or chromophoric DOM (CDOM). This chapter is dedicated to the origin, design, calibration, and use of in situ field fluorometers. It will serve as a review of considerations to be accounted for during the operation of fluorescence field sensors and call attention to areas of concern when making

  2. Real-time label-free quantitative fluorescence microscopy-based detection of ATP using a tunable fluorescent nano-aptasensor platform

    Science.gov (United States)

    Shrivastava, Sajal; Sohn, Il-Yung; Son, Young-Min; Lee, Won-Il; Lee, Nae-Eung

    2015-11-01

    Although real-time label-free fluorescent aptasensors based on nanomaterials are increasingly recognized as a useful strategy for the detection of target biomolecules with high fidelity, the lack of an imaging-based quantitative measurement platform limits their implementation with biological samples. Here we introduce an ensemble strategy for a real-time label-free fluorescent graphene (Gr) aptasensor platform. This platform employs aptamer length-dependent tunability, thus enabling the reagentless quantitative detection of biomolecules through computational processing coupled with real-time fluorescence imaging data. We demonstrate that this strategy effectively delivers dose-dependent quantitative readouts of adenosine triphosphate (ATP) concentration on chemical vapor deposited (CVD) Gr and reduced graphene oxide (rGO) surfaces, thereby providing cytotoxicity assessment. Compared with conventional fluorescence spectrometry methods, our highly efficient, universally applicable, and rational approach will facilitate broader implementation of imaging-based biosensing platforms for the quantitative evaluation of a range of target molecules.Although real-time label-free fluorescent aptasensors based on nanomaterials are increasingly recognized as a useful strategy for the detection of target biomolecules with high fidelity, the lack of an imaging-based quantitative measurement platform limits their implementation with biological samples. Here we introduce an ensemble strategy for a real-time label-free fluorescent graphene (Gr) aptasensor platform. This platform employs aptamer length-dependent tunability, thus enabling the reagentless quantitative detection of biomolecules through computational processing coupled with real-time fluorescence imaging data. We demonstrate that this strategy effectively delivers dose-dependent quantitative readouts of adenosine triphosphate (ATP) concentration on chemical vapor deposited (CVD) Gr and reduced graphene oxide (r

  3. Macromolecular-scale resolution in biological fluorescence microscopy.

    Science.gov (United States)

    Donnert, Gerald; Keller, Jan; Medda, Rebecca; Andrei, M Alexandra; Rizzoli, Silvio O; Lührmann, Reinhard; Jahn, Reinhard; Eggeling, Christian; Hell, Stefan W

    2006-08-01

    We demonstrate far-field fluorescence microscopy with a focal-plane resolution of 15-20 nm in biological samples. The 10- to 12-fold multilateral increase in resolution below the diffraction barrier has been enabled by the elimination of molecular triplet state excitation as a major source of photobleaching of a number of dyes in stimulated emission depletion microscopy. Allowing for relaxation of the triplet state between subsequent excitation-depletion cycles yields an up to 30-fold increase in total fluorescence signal as compared with reported stimulated emission depletion illumination schemes. Moreover, it enables the reduction of the effective focal spot area by up to approximately 140-fold below that given by diffraction. Triplet-state relaxation can be realized either by reducing the repetition rate of pulsed lasers or by increasing the scanning speed such that the build-up of the triplet state is effectively prevented. This resolution in immunofluorescence imaging is evidenced by revealing nanoscale protein patterns on endosomes, the punctuated structures of intermediate filaments in neurons, and nuclear protein speckles in mammalian cells with conventional optics. The reported performance of diffraction-unlimited fluorescence microscopy opens up a pathway for addressing fundamental problems in the life sciences.

  4. Smartphone-based fluorescence detector for mHealth.

    Science.gov (United States)

    Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

    2015-01-01

    We describe here a compact smartphone-based fluorescence detector for mHealth. A key element to achieving high sensitivity using low sensitivity phone cameras is a capillary array, which increases sensitivity by 100×. The capillary array was combined with a white LED illumination system to enable wide spectra fluorescent excitation in the range of 450-740 nm. The detector utilizes an orthographic projection system to form parallel light projection images from the capillaries at a close distance via an object-space telecentric lens configuration that reduces the total lens-to-object distance while maintaining uniformity in measurement between capillaries. To further increase the limit of detection (LOD), a computational image processing approach was employed to decrease the level of noise. This enables an additional 5-10× decrease in LOD. This smartphone-based detector was used to measure serial dilutions of fluorescein with a LOD of 1 nM with image stacking and 10 nM without image stacking, similar to the LOD obtained with a commercial plate reader. Moreover, the capillary array required a sample volume of less than 10 μl, which is an order of magnitude less than the 100 μl required for the plate reader.As fluorescence detection is widely used in sensitive biomedical assays, the approach described here has the potential to increase mHealth clinical utility, especially for telemedicine and for resource-poor settings in global health applications.

  5. Versatile protein tagging in cells with split fluorescent protein.

    Science.gov (United States)

    Kamiyama, Daichi; Sekine, Sayaka; Barsi-Rhyne, Benjamin; Hu, Jeffrey; Chen, Baohui; Gilbert, Luke A; Ishikawa, Hiroaki; Leonetti, Manuel D; Marshall, Wallace F; Weissman, Jonathan S; Huang, Bo

    2016-03-18

    In addition to the popular method of fluorescent protein fusion, live cell protein imaging has now seen more and more application of epitope tags. The small size of these tags may reduce functional perturbation and enable signal amplification. To address their background issue, we adapt self-complementing split fluorescent proteins as epitope tags for live cell protein labelling. The two tags, GFP11 and sfCherry11 are derived from the eleventh β-strand of super-folder GFP and sfCherry, respectively. The small size of FP11-tags enables a cost-effective and scalable way to insert them into endogenous genomic loci via CRISPR-mediated homology-directed repair. Tandem arrangement FP11-tags allows proportional enhancement of fluorescence signal in tracking intraflagellar transport particles, or reduction of photobleaching for live microtubule imaging. Finally, we show the utility of tandem GFP11-tag in scaffolding protein oligomerization. These experiments illustrate the versatility of FP11-tag as a labelling tool as well as a multimerization-control tool for both imaging and non-imaging applications.

  6. Multipoint fluorescence correlation spectroscopy with total internal reflection fluorescence microscope.

    Science.gov (United States)

    Ohsugi, Yu; Kinjo, Masataka

    2009-01-01

    We report simultaneous determination of diffusion coefficients at different points of a cell membrane using a multipoint fluorescence correlation spectroscopy (FCS) system. A system carrying seven detection areas in the evanescent field is achieved by using seven optical fibers on the image plane in the detection port of an objective-type total internal reflection FCS (TIR-FCS) system. Fluctuation of fluorescence intensity is monitored and evaluated using seven photomultiplier tubes (PMTs) and a newly constructed multichannel correlator. We demonstrate simultaneous-multipoint FCS, with a 3-mus time resolution, to investigate heterogeneous structures such as cell membranes and membrane-binding molecular dynamics near glass surfaces in live cells.

  7. Ultrasensitive fluorescence detection of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Mathies, R.A.; Glazer, A.N.

    1992-01-01

    We have shown that a number of polycationic highly fluorescent dyes form complexes with double-stranded DNA (dsDNA) which are stable to electrophoresis and have characterized in detail such dsDNA complexes with TOTO (1,1[prime]-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3-dihydro-(benzo-1,3-thiazole)-2-methylidene]-quinolinium tetraiodide) and oxazole yellow dimer (YOYO; an analogue of TOTO with a benzo-1,3-oxazole in place of the benzo-1,3-thiazole). TOTO and YOYO are virtually non-fluorescent in solution, but form highly fluorescent complexes with dsDNA, up to a maximum dye to DNA bp ratio of 1:4, with >1000-fold fluorescence enhancement. We have developed an assay using YOYO for the quantitation of single-stranded and dsDNA in solution applicable over a range of DNA concentrations from 0.5 to 100 ng per ml. The fluorescent dsDNA-dye complexes allow detection of dsDNA on agarose and acrylamide gels with picogram sensitivity. We have applied these complexes in multiplex mapping experiments for accurate sizing and quantitation of restriction fragments. We have shown that in gel shift experiments the stable dsDNA-dye complexes can be used to detect heteroduplex-Muts complexes with a sensitivity comparable to radioisotopic detection.

  8. [Reading by fluorescent lamp light].

    Science.gov (United States)

    Höfling, G

    1979-08-01

    In dioptrics courses it has hitherto been taught that eyes of near-sighted patients who work in fluorescent light should be slightly under-corrected, since the near point is approximated in bluish light as a result of the chromatic aberration of the eye, in contrast to its location in white light or even the reddish light of incandescent lamps. The theory further states that this recommendation does not apply if close-range refraction occurs under fluorescent light. However, this is seldom the case. In our own investigations this approximation of the near point, under uniform illumination by fluorescent strip lights running across the ceiling, did not occur, at least not in "white" light (No. 33). On the contrary, under an incandescent lamp which was only half as powerful the near point was regularly closer to the eye than under white fluorescent light. The recommendation for under-correction of pulpit spectacles computed in incandescent light can therefore no longer be upheld.--While many patients complain of difficulties in diffuse incandescent light, these may be due to several other illumination factors which have not yet been fully investigated.--Some fundamental differences between diffuse fluorescent lighting and incandescent lamp lighting where there is a fall-off in luminosity are described.

  9. Fluorescence and phosphorescence of rutin

    Energy Technology Data Exchange (ETDEWEB)

    Bondarev, Stanislav L., E-mail: bondarev@imaph.bas-net.by [Minsk State Higher Radioengineering College, 220005 Minsk (Belarus); Knyukshto, Valeri N. [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 220072 Minsk (Belarus)

    2013-10-15

    Rutin is one of the most promising flavonoid from a pharmacological and biochemical point of view. Here we have explored its spectroscopic and photophysical properties at room temperature and 77 K using steady-state absorption-luminescence methods and pulse spectroscopy equipment. By excitation into the absorption band 1 of rutin in methanol at room temperature the normal Stokes' shifted fluorescence with a maximum at 415 nm and quantum yield of 2×10{sup −4} was revealed. However, by excitation into the bands 2 and 3 any emission wasn’t observed. At 77 K in ethanol glass we have observed fluorescence at 410 nm and phosphorescence at 540 nm for the first time. As a result the adequate energetic scheme including the lowest electronic excited singlet at 26000 cm{sup −1} and triplet at 19600 cm{sup −1} states was proposed. -- Highlights: • Rutin fluorescence and phosphorescence at 77 K were revealed for the first time. • Room temperature fluorescence is determined by maximum at 415 nm and yield of 2×10{sup −4}. • Violation of Vavilov–Kasha rule by excitation into the absorption bands 2 and 3. • Fluorescence and phosphorescence in rutin are caused by the allowed π, π{sup (⁎)} transitions.

  10. Nanomaterial-Enabled Wearable Sensors for Healthcare.

    Science.gov (United States)

    Yao, Shanshan; Swetha, Puchakayala; Zhu, Yong

    2018-01-01

    Highly sensitive wearable sensors that can be conformably attached to human skin or integrated with textiles to monitor the physiological parameters of human body or the surrounding environment have garnered tremendous interest. Owing to the large surface area and outstanding material properties, nanomaterials are promising building blocks for wearable sensors. Recent advances in the nanomaterial-enabled wearable sensors including temperature, electrophysiological, strain, tactile, electrochemical, and environmental sensors are presented in this review. Integration of multiple sensors for multimodal sensing and integration with other components into wearable systems are summarized. Representative applications of nanomaterial-enabled wearable sensors for healthcare, including continuous health monitoring, daily and sports activity tracking, and multifunctional electronic skin are highlighted. Finally, challenges, opportunities, and future perspectives in the field of nanomaterial-enabled wearable sensors are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Enabling the Discovery of Gravitational Radiation

    Science.gov (United States)

    Isaacson, Richard

    2017-01-01

    The discovery of gravitational radiation was announced with the publication of the results of a physics experiment involving over a thousand participants. This was preceded by a century of theoretical work, involving a similarly large group of physicists, mathematicians, and computer scientists. This huge effort was enabled by a substantial commitment of resources, both public and private, to develop the different strands of this complex research enterprise, and to build a community of scientists to carry it out. In the excitement following the discovery, the role of key enablers of this success has not always been adequately recognized in popular accounts. In this talk, I will try to call attention to a few of the key ingredients that proved crucial to enabling the successful discovery of gravitational waves, and the opening of a new field of science.

  12. Characteristics of green-blue fluorescence generated from the adaxial sides of leaves of tree species.

    Science.gov (United States)

    Nakayama, Masayoshi; Iwashina, Tsukasa

    2017-03-01

    We discovered that some tree species have leaves whose adaxial sides show bright green-blue fluorescence upon exposure to ultraviolet irradiation. In total, 141 native Japanese species belonging to 47 families were analyzed, and the brightness of the leaf fluorescence, represented by the L* values (Lab color space) of the pictures, was evaluated. The species possessing the brightest fluorescent leaves, with L* > 50, were Camellia japonica, Camellia sasanqua, and Cleyera japonica of Theaceae, Osmanthus heterophyllus and Ligustrum japonicum of Oleaceae, Aucuba japonica of Garryaceae, and Trochodendron aralioides of Trochodendraceae. These species are propagated by pollination or seed dispersion by birds, except T. aralioides. The fluorescence was specifically observed in the cuticle tissues of the epidermal cells, indicating that the fluorescence is a signal to other organisms that can perceive the fluorescence under natural light. Species possessing the bright leaves represented 5% of the total species tested, while species possessing dark leaves, with L* ≤ 40, represented 88.6%. We deduce that the fluorescence enables the organisms to easily distinguish the minority species possessing bright leaves from the surrounding plants, which were mostly trees species with dark leaves. The structure of A. japonica var. borealis, in which dark leaves only surround its fruits while the rest of the tree is covered by bright leaves, may be useful to signal the presence of fruits to the organisms. We hypothesize that the fluorescence contributes to the propagation of the tree species by helping birds to distinguish these particular trees and/or locate the fruits.

  13. A starting point for fluorescence-based single-molecule measurements in biomolecular research.

    Science.gov (United States)

    Gust, Alexander; Zander, Adrian; Gietl, Andreas; Holzmeister, Phil; Schulz, Sarah; Lalkens, Birka; Tinnefeld, Philip; Grohmann, Dina

    2014-09-30

    Single-molecule fluorescence techniques are ideally suited to provide information about the structure-function-dynamics relationship of a biomolecule as static and dynamic heterogeneity can be easily detected. However, what type of single-molecule fluorescence technique is suited for which kind of biological question and what are the obstacles on the way to a successful single-molecule microscopy experiment? In this review, we provide practical insights into fluorescence-based single-molecule experiments aiming for scientists who wish to take their experiments to the single-molecule level. We especially focus on fluorescence resonance energy transfer (FRET) experiments as these are a widely employed tool for the investigation of biomolecular mechanisms. We will guide the reader through the most critical steps that determine the success and quality of diffusion-based confocal and immobilization-based total internal reflection fluorescence microscopy. We discuss the specific chemical and photophysical requirements that make fluorescent dyes suitable for single-molecule fluorescence experiments. Most importantly, we review recently emerged photoprotection systems as well as passivation and immobilization strategies that enable the observation of fluorescently labeled molecules under biocompatible conditions. Moreover, we discuss how the optical single-molecule toolkit has been extended in recent years to capture the physiological complexity of a cell making it even more relevant for biological research.

  14. High-precision correlative fluorescence and electron cryo microscopy using two independent alignment markers

    Energy Technology Data Exchange (ETDEWEB)

    Schellenberger, Pascale [Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Kaufmann, Rainer [Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Siebert, C. Alistair; Hagen, Christoph [Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Wodrich, Harald [Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, University of Bordeaux SEGALEN, 146 rue Leo Seignat, 33076 Bordeaux (France); Grünewald, Kay, E-mail: kay@strubi.ox.ac.uk [Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom)

    2014-08-01

    Correlative light and electron microscopy (CLEM) is an emerging technique which combines functional information provided by fluorescence microscopy (FM) with the high-resolution structural information of electron microscopy (EM). So far, correlative cryo microscopy of frozen-hydrated samples has not reached better than micrometre range accuracy. Here, a method is presented that enables the correlation between fluorescently tagged proteins and electron cryo tomography (cryoET) data with nanometre range precision. Specifically, thin areas of vitrified whole cells are examined by correlative fluorescence cryo microscopy (cryoFM) and cryoET. Novel aspects of the presented cryoCLEM workflow not only include the implementation of two independent electron dense fluorescent markers to improve the precision of the alignment, but also the ability of obtaining an estimate of the correlation accuracy for each individual object of interest. The correlative workflow from plunge-freezing to cryoET is detailed step-by-step for the example of locating fluorescence-labelled adenovirus particles trafficking inside a cell. - Highlights: • Vitrified mammalian cell were imaged by fluorescence and electron cryo microscopy. • TetraSpeck fluorescence markers were added to correct shifts between cryo fluorescence channels. • FluoSpheres fiducials were used as reference points to assign new coordinates to cryoEM images. • Adenovirus particles were localised with an average correlation precision of 63 nm.

  15. A Starting Point for Fluorescence-Based Single-Molecule Measurements in Biomolecular Research

    Directory of Open Access Journals (Sweden)

    Alexander Gust

    2014-09-01

    Full Text Available Single-molecule fluorescence techniques are ideally suited to provide information about the structure-function-dynamics relationship of a biomolecule as static and dynamic heterogeneity can be easily detected. However, what type of single-molecule fluorescence technique is suited for which kind of biological question and what are the obstacles on the way to a successful single-molecule microscopy experiment? In this review, we provide practical insights into fluorescence-based single-molecule experiments aiming for scientists who wish to take their experiments to the single-molecule level. We especially focus on fluorescence resonance energy transfer (FRET experiments as these are a widely employed tool for the investigation of biomolecular mechanisms. We will guide the reader through the most critical steps that determine the success and quality of diffusion-based confocal and immobilization-based total internal reflection fluorescence microscopy. We discuss the specific chemical and photophysical requirements that make fluorescent dyes suitable for single-molecule fluorescence experiments. Most importantly, we review recently emerged photoprotection systems as well as passivation and immobilization strategies that enable the observation of fluorescently labeled molecules under biocompatible conditions. Moreover, we discuss how the optical single-molecule toolkit has been extended in recent years to capture the physiological complexity of a cell making it even more relevant for biological research.

  16. Origami-enabled deformable silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Tu, Hongen; Xu, Yong [Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, Michigan 48202 (United States); Song, Zeming; Jiang, Hanqing, E-mail: hanqing.jiang@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Yu, Hongyu, E-mail: hongyu.yu@asu.edu [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States)

    2014-02-24

    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

  17. Compressive fluorescence microscopy for biological and hyperspectral imaging.

    Science.gov (United States)

    Studer, Vincent; Bobin, Jérome; Chahid, Makhlad; Mousavi, Hamed Shams; Candes, Emmanuel; Dahan, Maxime

    2012-06-26

    The mathematical theory of compressed sensing (CS) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth. Whereas the CS theory is now well developed, challenges concerning hardware implementations of CS-based acquisition devices--especially in optics--have only started being addressed. This paper presents an implementation of compressive sensing in fluorescence microscopy and its applications to biomedical imaging. Our CS microscope combines a dynamic structured wide-field illumination and a fast and sensitive single-point fluorescence detection to enable reconstructions of images of fluorescent beads, cells, and tissues with undersampling ratios (between the number of pixels and number of measurements) up to 32. We further demonstrate a hyperspectral mode and record images with 128 spectral channels and undersampling ratios up to 64, illustrating the potential benefits of CS acquisition for higher-dimensional signals, which typically exhibits extreme redundancy. Altogether, our results emphasize the interest of CS schemes for acquisition at a significantly reduced rate and point to some remaining challenges for CS fluorescence microscopy.

  18. Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy.

    Science.gov (United States)

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

    2011-03-14

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

  19. Characterization of Fluorescent Polystyrene Microspheres for Advanced Flow Diagnostics

    Science.gov (United States)

    Maisto, Pietro M. F.; Lowe, K. Todd; Byun, Guibo; Simpson, Roger; Vercamp, Max; Danley, Jason E.; Koh, Brian; Tiemsin, Pacita; Danehy, Paul M.; Wohl, Christopher J.

    2013-01-01

    Fluorescent dye-doped polystyrene latex microspheres (PSLs) are being developed for velocimetry and scalar measurements in variable property flows. Two organic dyes, Rhodamine B (RhB) and dichlorofluorescence (DCF), are examined to assess laser-induced fluorescence (LIF) properties for flow imaging applications and single-shot temperature measurements. A major interest in the current research is the application of safe dyes, thus DCF is of particular interest, while RhB is used as a benchmark. Success is demonstrated for single-point laser Doppler velocimetry (LDV) and also imaging fluorescence, excited via a continuous wave 2 W laser beam, for exposures down to 10 ms. In contrast, when exciting with a pulsed Nd:YAG laser at 200 mJ/pulse, no fluorescence was detected, even when integrating tens of pulses. We show that this is due to saturation of the LIF signal at relatively low excitation intensities, 4-5 orders of magnitude lower than the pulsed laser intensity. A two-band LIF technique is applied in a heated jet, indicating that the technique effectively removes interfering inputs such as particle diameter variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about +/-12.5 C precision, while future improvements in dye temperature sensitivity and signal quality may enable single-shot temperature measurements with sub-degree precision.

  20. Ratiometric fluorescent nanosensors for selective detecting cysteine with upconversion luminescence.

    Science.gov (United States)

    Guan, Yunlong; Qu, Songnan; Li, Bin; Zhang, Liming; Ma, Heping; Zhang, Ligong

    2016-03-15

    Fluorescent sensors based on upconversion (UC) luminescence have been considered as a promising strategy to detect bio-analyte due to their advantages in deep penetration, minimum autofluorescence, and ratiometric fluorescent output. A prototype of nanosensors combined with mesoporous silica coated upconversion nanoparticles (UCNPs) and a fluorescein-based fluorescent probe loaded in pores was therefore designed to detect cysteine (Cys). The silica shell provided loading space for the probe and enabled the nanosensors to disperse in water. In the presence of Cys, the fluorescent probe was transformed into 5(6)-carboxyfluorescein with an emission band centering at 518 nm which was secondarily excited by the light at around 475 nm from NaYF4:Yb(3+), Tm(3+) UCNPs driven by 980 nm near-infrared (NIR) laser. The intensity ratio between green and blue luminescence (I518/I475) grew exponentially with increasing concentrations of Cys over a range of 20-200 μmolL(-1). The response of the nanosensors towards Cys was recognizable with naked eyes by luminescence color change. Evidences suggest that these nanosensors are capable of sensing Cys in aqueous solution and distinguishing Cys from homocysteine (Hcy) with kinetically-controlled selectivity. The system was further employed to detect Cys in human serum and the result was in agreement with it tested by high performance liquid chromatography with acceptable recovery. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. In vivo labelling of Anagallis arvensis L. cells with green fluorescent protein

    OpenAIRE

    Marcin Łukaszewicz; Dorota Kwiatkowska

    2014-01-01

    A few methods only enable to follow the fate of plant cells in vivo. One of the most promising is using the Green Fluorescent Protein (GFP). In our preliminary study we set up the experimental system enabling labelling of Anagallis arvensis cells with this marker. We prepared an expression plasmid containing red-shifted gfp with optimised translation start site context, under the control of CaMV 35S transcription promoter. The construct was introduced into A. arvensis cells by particle bombar...

  2. Fluorescence confocal microscopy for pathologists.

    Science.gov (United States)

    Ragazzi, Moira; Piana, Simonetta; Longo, Caterina; Castagnetti, Fabio; Foroni, Monica; Ferrari, Guglielmo; Gardini, Giorgio; Pellacani, Giovanni

    2014-03-01

    Confocal microscopy is a non-invasive method of optical imaging that may provide microscopic images of untreated tissue that correspond almost perfectly to hematoxylin- and eosin-stained slides. Nowadays, following two confocal imaging systems are available: (1) reflectance confocal microscopy, based on the natural differences in refractive indices of subcellular structures within the tissues; (2) fluorescence confocal microscopy, based on the use of fluorochromes, such as acridine orange, to increase the contrast epithelium-stroma. In clinical practice to date, confocal microscopy has been used with the goal of obviating the need for excision biopsies, thereby reducing the need for pathological examination. The aim of our study was to test fluorescence confocal microscopy on different types of surgical specimens, specifically breast, lymph node, thyroid, and colon. The confocal images were correlated to the corresponding histological sections in order to provide a morphologic parallel and to highlight current limitations and possible applications of this technology for surgical pathology practice. As a result, neoplastic tissues were easily distinguishable from normal structures and reactive processes such as fibrosis; the use of fluorescence enhanced contrast and image quality in confocal microscopy without compromising final histologic evaluation. Finally, the fluorescence confocal microscopy images of the adipose tissue were as accurate as those of conventional histology and were devoid of the frozen-section-related artefacts that can compromise intraoperative evaluation. Despite some limitations mainly related to black/white images, which require training in imaging interpretation, this study confirms that fluorescence confocal microscopy may represent an alternative to frozen sections in the assessment of margin status in selected settings or when the conservation of the specimen is crucial. This is the first study to employ fluorescent confocal microscopy on

  3. Genetically Encoded Fluorescent Redox Probes

    Directory of Open Access Journals (Sweden)

    Hui-Wang Ai

    2013-11-01

    Full Text Available Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, advantages and pitfalls. Our recent work on reaction-based encoded probes that are responsive to particular redox signaling molecules is also reviewed. Future challenges and directions are also commented.

  4. Genetically encoded fluorescent redox probes.

    Science.gov (United States)

    Ren, Wei; Ai, Hui-Wang

    2013-11-11

    Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, advantages and pitfalls. Our recent work on reaction-based encoded probes that are responsive to particular redox signaling molecules is also reviewed. Future challenges and directions are also commented.

  5. [Fluorescence spectra of ponceau-4R].

    Science.gov (United States)

    Shi, Ai-Min; Zhu, Tuo; Gu, En-Dong; Liu, Zhou-Yi; Xu, Hui

    2009-01-01

    The fluorescence spectra of ponceau 4R induced by 220-400 nm light were studied in the present paper. The result shows that ponceau 4R has four obvious fluorescence spectral peaks respectively located at 420, 530, 635 and 687 nm, each of these fluorescence spectral peaks has different best induced light, and the corresponding fluorescence spectra were listed. It was considered that this fluorescence comes from the transition n --> pi* of n electrons in the -OH and pi* --> pi of pi electrons in the naphthalene. The fluorescence spectral peaks at 420 nm come from the transition n --> pi* and the other three fluorescence spectral peaks come from pi* --> pi. But the intensity of the four fluorescence spectral peaks changes differently with the excited wavelength This paper attempted to give the expression of the four fluorescence spectral peaks based on the microcosmic mechanism. The reason for that ponceau 4R has complex fluorescence characteristic is that ponceau 4R not only has big and conjugate structure such as naphthalene and provides electron group -OH which can intensify its ability to emit fluorescence, but also absorbs electron group such as N=N which can depress its ability to emit fluorescence. Investigation on the fluorescence spectra and its characteristics will contribute to the study on the fluorescence spectra of other azo pigment and help find a new way for checking food safety.

  6. Fluorescence lifetime standards for time and frequency domain fluorescence spectroscopy

    NARCIS (Netherlands)

    Boens, N.; Qin, Wenwu; Basaric, N.; Hofkens, J.; Ameloot, M.; Pouget, J.; Lefevre, J.P.; Valeur, B.; Gratton, E.; Ven, van de M.; Silva jr., D.; Engelborghs, Y.; Willaert, K.; Sillen, A.; Rumbles, G.; Philips, D.; Visser, A.J.W.G.; Hoek, van A.; Lakowicz, J.R.; Malak, H.; Gryczynski, I.; Szabo, A.G.; Krajcarski, D.T.; Tamai, N.; Miura, A.

    2007-01-01

    A series of fluorophores with single-exponential fluorescence decays in liquid solution at 20 C were measured independently by nine laboratories using single-photon timing and multifrequency phase and modulation fluorometry instruments with lasers as excitation source. The dyes that can serve as

  7. PH-sensitive fluorescence detection by diffuse fluorescence tomography

    Science.gov (United States)

    Li, Jiao; Gao, Feng; Duan, Linjing; Wang, Xin; Zhang, Limin; Zhao, Huijuan

    2012-03-01

    The importance of cellular pH has been shown clearly in the study of cell activity, pathological feature, drug metabolism, etc. Monitoring pH changes of living cells and imaging the regions with abnormal pH values in vivo could provide the physiologic and pathologic information for the research of the cell biology, pharmacokinetics, diagnostics and therapeutics of certain diseases such as cancer. Thus, pH-sensitive fluorescence imaging of bulk tissues has been attracting great attention in the regime of near-infrared diffuse fluorescence tomography (DFT), an efficient small-animal imaging tool. In this paper, the feasibility of quantifying pH-sensitive fluorescence targets in turbid medium is investigated using both time-domain and steady-state DFT methods. By use of the specifically designed time-domain and continuous-wave systems and the previously proposed image reconstruction scheme, we validate the method through 2-dimensional imaging experiments on a small-animal-sized phantom with multiply targets of distinct pH values. The results show that the approach can localize the targets with reasonable accuracy and achieve quantitative reconstruction of the pH-sensitive fluorescent yield.

  8. Enabling DRM-preserving Digital content Redistribution

    NARCIS (Netherlands)

    Krishnan Nair, S.; Popescu, B.C.; Gamage, C.D.; Crispo, B.; Tanenbaum, A.S.

    2005-01-01

    Traditionally, the process of online digital content distribution has involved a limited number of centralised distributors selling protected contents and licenses authorising the use of the se contents, to consumers. In this paper, we extend this model by introducing a security scheme that enables

  9. ICT-Enabled Learning: The Student Perspective

    Science.gov (United States)

    Scott, Geoff; Grebennikov, Leonid; Gozzard, Terry

    2009-01-01

    This research seeks to contribute to current discussions in Australian higher education on how best to deploy ICT-enabled learning. Its particular focus is on examining the qualitative data from students on their experience of using Information and Communication Technologies (ICT) at one college in an Australian university. In total, about 71,240…

  10. Creating an Economically Enabling and Competitive Business ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Creating an Economically Enabling and Competitive Business Environment in the West Bank and Gaza Strip. The prospect of indefinite Israeli occupation of the ... Impact of implementing the Palestinian banking law on the performance of the private sector [Arabic language]. Documents. Impact of the commercial agents law ...

  11. Interaction between COCHLEATA and UNIFOLIATA genes enables ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 90; Issue 2. Interaction between COCHLEATA and UNIFOLIATA genes enables normal flower morphogenesis in the garden pea, Pisum sativum. Sushil Kumar Vishakha Sharma Swati Chaudhary Renu Kumari Nisha Kumari Poonam Mishra. Research Note Volume 90 Issue 2 ...

  12. Extreme Networks' 10-Gigabit Ethernet enables

    CERN Multimedia

    2002-01-01

    " Extreme Networks, Inc.'s 10-Gigabit switching platform enabled researchers to transfer one Terabyte of information from Vancouver to Geneva across a single network hop, the world's first large-scale, end-to-end transfer of its kind" (1/2 page).

  13. Creating an Economically Enabling and Competitive Business ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Creating an Economically Enabling and Competitive Business Environment in the West Bank and Gaza Strip. The prospect of indefinite Israeli occupation of the Palestinian territories, and their extreme ... Country(s). Middle East, North of Sahara, South of Sahara, Central Asia, Far East Asia, South Asia, Palestine ...

  14. 75 FR 13235 - IP-Enabled Services

    Science.gov (United States)

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 63 IP-Enabled Services AGENCY: Federal Communications Commission ACTION: Final rule... interconnected Voice over Internet Protocol (VoIP) service the discontinuance obligations that apply to domestic...

  15. Caring at home until death: enabled determination.

    Science.gov (United States)

    Robinson, Carole A; Bottorff, Joan L; McFee, Erin; Bissell, Laura J; Fyles, Gillian

    2017-04-01

    The importance of family caregivers in providing palliative care at home and in supporting a home death is well supported. Gaining a better understanding of what enables palliative family caregivers to continue caring at home for their family members until death is critical to providing direction for more effective support. The purpose of the study was to describe the experiences of bereaved family caregivers whose terminally ill family members with advanced cancer were successful in achieving a desired home death. A qualitative interpretive descriptive approach was used. Data were collected using semi-structured, audio-recorded interviews conducted in-person or via telephone in addition to field notes and reflective journaling. The study took place in British Columbia, Canada, and included 29 bereaved adult family caregivers who had provided care for a family member with advanced cancer and experienced a home death. Four themes captured the experience of caring at home until death: context of providing care, supportive antecedents to providing care, determination to provide care at home, and enabled determination. Factors that enabled determination to achieve a home death included initiation of formal palliative care, asking for and receiving help, augmented care, relief or respite, and making the healthcare system work for the ill person. Clarifying caregiving goals and supporting the factors that enable caregiver determination appear to be critical in enhancing the likelihood of a desired home death.

  16. School Bureaucracies That Work: Enabling, Not Coercive.

    Science.gov (United States)

    Hoy, Wayne K.; Sweetland, Scott R.

    2000-01-01

    Attempts to reconcile two theoretically opposing perspectives of bureaucracy (as either alienating or facilitative) by creating and testing a new construct called "enabling bureaucracy." Empirical results are encouraging. Schools can be designed with formalized procedures and hierarchical structures that help rather than hinder teaching and…

  17. Enablers & Barriers for Realizing Modularity Benefits

    DEFF Research Database (Denmark)

    Storbjerg, Simon Haahr; Brunø, Thomas Ditlev; Thyssen, Jesper

    2012-01-01

    are the organizational and systems related aspects. Recognizing the need for guidance to realize the benefits of modularity, the purpose of this study is through a literature study and a case study to improve the insight into the organizational and systems related enablers and barriers with regard to obtaining the full...

  18. Enabling Efficient Intelligence Analysis in Degraded Environments

    Science.gov (United States)

    2013-06-01

    When facing decisions in underdeveloped, degraded, and denied environments, commanders are likely to rely even more heavily on efficient intelligence ... analysis . Unfortunately, most of the time, the data gathered in these environments will be uncertain, ambiguous, and incomplete. Tools enabling fast

  19. Use of fluorescent Ca2+ dyes with green fluorescent protein and its variants: problems and solutions.

    OpenAIRE

    Bolsover, S.; O. Ibrahim; O'luanaigh, N; Williams, H; Cockcroft, S

    2001-01-01

    We have studied the degree to which fluorescent Ca(2+) indicator dyes, and green fluorescent protein and its variants, can be used together. We find that the most commonly used fluorescent protein, enhanced green fluorescent protein (EGFP), seriously contaminates fura 2 signals. We suggest two alternative combinations for which there is no detectable contamination of the Ca(2+) indicator signal by the fluorescent protein. Blue fluorescent protein can be used with the Ca(2+) indicator Fura Red...

  20. Cell wall staining with Trypan Blue enables quantitative analysis of morphological changes in yeast cells

    Directory of Open Access Journals (Sweden)

    Johannes eLiesche

    2015-02-01

    Full Text Available Yeast cells are protected by a cell wall that plays an important role in the exchange of substances with the environment. The cell wall structure is dynamic and can adapt to different physiological states or environmental conditions. For the investigation of morphological changes, selective staining with fluorescent dyes is a valuable tool. Furthermore, cell wall staining is used to facilitate sub-cellular localization experiments with fluorescently-labeled proteins and the detection of yeast cells in non-fungal host tissues. Here, we report staining of Saccharomyces cerevisiae cell wall with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals, demonstrating the potential of this approach for morphological investigations or screening assays.

  1. A DNA Walker as a Fluorescence Signal Amplifier.

    Science.gov (United States)

    Wang, Dongfang; Vietz, Carolin; Schröder, Tim; Acuna, Guillermo; Lalkens, Birka; Tinnefeld, Philip

    2017-09-13

    Sensing nucleic acids typically involves the recognition of a specific sequence and reporting by, for example, a fluorogenic reaction yielding one activated dye molecule per detected nucleic acid. Here, we show that after binding to a DNA origami track a bound DNA target (a "DNA walker") can release the fluorescence of many molecules by acting as the catalyst of an enzymatic nicking reaction. As the walking kinetics sensitively depends on the walker sequence, the resulting brightness distribution of DNA origamis is a sequence fingerprint with single-nucleotide sensitivity. Using Monte Carlo simulations, we rationalize that the random self-avoiding walk is mainly terminated when steps to nearest neighbors are exhausted. Finally, we demonstrate that the DNA walker is also active in a plasmonic hotspot for fluorescence enhancement, indicating the potential of combining different amplification mechanisms enabled by the modularity of DNA nanotechnology.

  2. Computational framework for simulating fluorescence microscope images with cell populations.

    Science.gov (United States)

    Lehmussola, Antti; Ruusuvuori, Pekka; Selinummi, Jyrki; Huttunen, Heikki; Yli-Harja, Olli

    2007-07-01

    Fluorescence microscopy combined with digital imaging constructs a basic platform for numerous biomedical studies in the field of cellular imaging. As the studies relying on analysis of digital images have become popular, the validation of image processing methods used in automated image cytometry has become an important topic. Especially, the need for efficient validation has arisen from emerging high-throughput microscopy systems where manual validation is impractical. We present a simulation platform for generating synthetic images of fluorescence-stained cell populations with realistic properties. Moreover, we show that the synthetic images enable the validation of analysis methods for automated image cytometry and comparison of their performance. Finally, we suggest additional usage scenarios for the simulator. The presented simulation framework, with several user-controllable parameters, forms a versatile tool for many kinds of validation tasks, and is freely available at http://www.cs.tut.fi/sgn/csb/simcep.

  3. High-Resolution Fluorescence Microscope Imaging of Erythroblast Structure.

    Science.gov (United States)

    Smith, Alyson S; Nowak, Roberta B; Fowler, Velia M

    2018-01-01

    During erythropoiesis, erythroblasts undergo dramatic morphological changes to produce mature erythrocytes. Many unanswered questions regarding the molecular mechanisms behind these changes can be addressed with high-resolution fluorescence imaging. Immunofluoresence staining enables localization of specific molecules, organelles, and membrane components in intact cells at different phases of erythropoiesis. Confocal laser scanning microscopy can provide high-resolution, three-dimensional images of stained structures, which can be used to dissect the molecular mechanisms driving erythropoiesis. The sample preparation, staining procedure, imaging parameters, and image analysis methods used directly affect the quality of the confocal images and the amount and accuracy of information that they can provide. Here, we describe methods to dissect erythropoietic tissues from mice, to perform immunofluorescence staining and confocal imaging of various molecules, organelles and structures of interest in erythroblasts, and to present and quantitatively analyze the data obtained in these fluorescence images.

  4. Chemical Fluorescent Probe for Detection of Aβ Oligomers.

    Science.gov (United States)

    Teoh, Chai Lean; Su, Dongdong; Sahu, Srikanta; Yun, Seong-Wook; Drummond, Eleanor; Prelli, Frances; Lim, Sulgi; Cho, Sunhee; Ham, Sihyun; Wisniewski, Thomas; Chang, Young-Tae

    2015-10-28

    Aggregation of amyloid β-peptide (Aβ) is implicated in the pathology of Alzheimer's disease (AD), with the soluble, Aβ oligomeric species thought to be the critical pathological species. Identification and characterization of intermediate species formed during the aggregation process is crucial to the understanding of the mechanisms by which oligomeric species mediate neuronal toxicity and following disease progression. Probing these species proved to be extremely challenging, as evident by the lack of reliable sensors, due to their heterogeneous and transient nature. We describe here an oligomer-specific fluorescent chemical probe, BoDipy-Oligomer (BD-Oligo), developed through the use of the diversity-oriented fluorescent library approach (DOFLA) and high-content, imaging-based screening. This probe enables dynamic oligomer monitoring during fibrillogenesis in vitro and shows in vivo Aβ oligomers staining possibility in the AD mice model.

  5. Fluorescence microscopy imaging of electroperturbation in mammalian cells.

    Science.gov (United States)

    Sun, Yinghua; Vernier, P Thomas; Behrend, Matthew; Wang, Jingjing; Thu, Mya Mya; Gundersen, Martin; Marcu, Laura

    2006-01-01

    We report the design, integration, and validation of a fluorescence microscopy system for imaging of electroperturbation--the effects of nanosecond, megavolt-per-meter pulsed electric fields on biological cells and tissues. Such effects have potential applications in cancer therapy, gene regulation, and biophysical research by noninvasively disrupting intracellular compartments and inducing apoptosis in malignant cells. As the primary observing platform, an epifluorescence microscope integrating a nanosecond high-voltage pulser and a micrometer electrode chamber enable in situ imaging of the intracellular processes triggered by high electric fields. Using specific fluorescence molecular probes, the dynamic biological responses of Jurkat T lymphocytes to nanosecond electric pulses (nanoelectropulses) are studied with this system, including calcium bursts, the polarized translocation of phosphatidylserine (PS), and nuclear enlargement and chromatin/DNA structural changes.

  6. Identification and use of fluorescent dyes for plant cell wall imaging using high-throughput screening.

    Science.gov (United States)

    Anderson, Charles T; Carroll, Andrew

    2014-01-01

    Plant cell walls define cell shape during development and are composed of interlaced carbohydrate and protein networks. Fluorescent dyes have long been used to label plant cell walls, enabling optical microscopy-based interrogation of cell wall structure and composition. However, the specific cell wall components to which these dyes bind are often poorly defined. The availability of fluorescent compound libraries provides the potential to screen for and identify new fluorescent compounds that interact with specific plant cell wall components, enabling the study of cell wall architecture in intact, living tissues. Here, we describe a technique for screening fluorescent compound libraries for enhanced fluorescence upon interaction with plant cell walls, a secondary screening method to identify which cell wall components interact with a given dye, and a protocol for staining and observing Arabidopsis seedlings using a fluorescent cell wall-labeling dye. These methods have the potential to be applied to screening for differences in cell wall structure and composition among genetically diverse plant varieties or species.

  7. Max Tech and Beyond: Fluorescent Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Scholand, Michael

    2012-04-01

    contains less material (i.e., glass, fill gas and phosphor), and has a higher luminance, enabling fixtures to take advantage of the smaller lamp size to improve the optics and provide more efficient overall system illuminance. In addition to offering the market a high-quality efficacious light source, another strong value proposition of fluorescent lighting is its long operating life. In today's market, one manufacturer is offering fluorescent lamps that have a rated life of 79,000 hours - which represents 18 years of service at 12 hours per day, 365 days per year. These lamps, operated using a long-life ballast specified by the manufacturer, take advantage of improvements in cathode coatings, fill gas chemistry and pressure to extend service life by a factor of four over conventional fluorescent lamps. It should be noted that this service life is also longer (approximately twice as long) as today's high-quality LED products. The fluorescent market is currently focused on the T5 and T8 lamp diameters, and it is not expected that other diameters would be introduced. Although T8 is a more optimal diameter from an efficacy perspective, the premium efficiency and optimization effort has been focused on T5 lamps because they are 40% smaller than T8, and are designed to operate at a higher temperature using high-frequency electronic ballasts. The T5 lamp offers savings in terms of materials, packaging and shipping, as well as smaller fixtures with improved optical performance. Manufacturers are actively researching improvements in four critical areas that are expected to yield additional efficacy improvements of approximately 10 to 14 percent over the next five years, ultimately achieving approximately 130 lumens per watt by 2015. The active areas of research where these improvements are anticipated include: (1) Improved phosphors which continue to be developed and patented, enabling higher efficacies as well as better color rendering and lumen maintenance; (2

  8. A Dimmable Electrodeless Fluorescent Lamp

    Science.gov (United States)

    Chen, Yuming; Long, Qi; Chen, Dahua; Li, Weide; Wang, Aiqun

    A dimmable electrodeless fluorescent lamp (induction lamp) is introduced in this paper. The principles of the induction lamp are introduced in details. A dimming approach for the lamp is discussed in both theory and experiment. A continuous dimming range from 30%-100% can be realized with the application of the IC chip.

  9. Fluorescence Spectroscopy in a Shoebox

    Science.gov (United States)

    Farooq Wahab, M.

    2007-08-01

    This article describes construction of a simple, inexpensive fluorometer. It utilizes a flashlight or sunlight source, highlighter marker ink, bowl of water with mirror as dispersing element, and colored cellophane sheets as filters. The human eye is used as a detector. This apparatus is used to demonstrate important concepts related to fluorescence spectroscopy. Using ink from a highlighter marker, one can demonstrate the difference between light scattering and fluorescence emission, the need for an intense light source, phenomenon of the Stokes shift, the choice of filters, the preferred geometry of excitation source and emission detector, and the low detection limits that can be achieved by fluorescence measurements. By reflecting the fluorescence emission from a compact disk, it can be seen that the light emitted by molecules is not monochromatic. Furthermore, a spectrofluorometer is constructed using gratings made from a DVD or a CD. The shoebox fluorometer and spectrofluorometer can serve as useful teaching aids in places where commercial instruments are not available, and it avoids the black box problem of modern instruments.

  10. Fluorescence Spectroscopy and its Applications

    Indian Academy of Sciences (India)

    TECS

    ferent aspects of fluorescence spectroscopy and applications in chemistry, which I hope would be useful to both chemists and spectroscopists. I thank the Indian Academy of Sciences and, in particular, the Editorial. Board of the Journal of Chemical Sciences for inviting me to be the Guest. Editor of this Special Issue.

  11. Fluorescence for high school students

    NARCIS (Netherlands)

    Schultheiss, N.G.; Kool, T.W.

    2012-01-01

    In a not obligatory series of lessons for high school students in the Netherlands we discuss the fluorescence aspects of anthracene. These lessons were developed because HiSPARC (High school Project on Astrophysics Research with Cosmics) detection of cosmic rays are available for different secondary

  12. Fluorescence diagnostics in oncological gynecology

    Science.gov (United States)

    Belyaeva, Ludmila A.; Adamyan, Leila V.; Kozachenko, Vladimir P.; Stratonnikov, Alexander A.; Stranadko, Eugene F.; Loschenov, Victor B.

    2003-10-01

    The method of fluorescent diagnostics (FD) of tumors is a promising tool that may allow to increase sensitivity of tumor detection especially at initial stages. One of the most promising photosensitizers today is 5-aminolevulinic acid (5-ALA) that, actually, is not photosensitizer itself but precursor of protoporphyrin IX (PpIX). This paper deals with cancer diagnostics in gynecology by means of ALA-induced Pp IX laser-fluorescence spectroscopy. The tissue fluorescence spectra in vivo were studied in patients with various pathologies of ovaries, uterine and vulva after 5-aminolevulinic acid administration. It was shown that different pathologies varies in accumulation of Pp IX. Coefficient of fluorescence kf for normal tissue is not high, but exceptions are endometrium and mucous membrane of uterine tubes. Benign tumors of uterus and ovary have low values of kf, but polyps of endometrium exhibit high kf. Optical express-biopsy is important for diagnosis of ovarian cancer and micrometastatic spread. Coefficients of diagnostic contrast were determined for cancer of endometrium, cervical cancer, vulvar cancer.

  13. Fluorescence monitoring of capillary electrophoresis separation of biomolecules with monolithically integrated optical waveguides

    NARCIS (Netherlands)

    Dongre, C.; Dekker, R.; Hoekstra, Hugo; Martinez-Vazquez, R.; Osellame, R.; Ramponi, R.; Cerullo, G.; van Weeghel, R.; Besselink, G.A.J.; van den Vlekkert, H.H.; Pollnau, Markus

    2009-01-01

    Monolithic integration of optical waveguides in a commercial lab-on-a-chip by femtosecond-laser material processing enables arbitrary 3D geometries of optical sensing structures in combination with fluidic microchannels. Integrated fluorescence monitoring of molecular separation, as applicable in

  14. Nitroreductase-triggered activation of a novel caged fluorescent probe obtained from methylene blue.

    Science.gov (United States)

    Bae, Jungeun; McNamara, Louis E; Nael, Manal A; Mahdi, Fakhri; Doerksen, Robert J; Bidwell, Gene L; Hammer, Nathan I; Jo, Seongbong

    2015-08-18

    A near-infrared fluorescent probe based on methylene blue (p-NBMB) was developed for the detection of nitroreductase. Conjugating methylene blue with a p-nitrobenzyl moiety enables it to be activated by nitroreductase-catalyzed 1,6-elimination, resulting in the release of an active methylene blue fluorophore.

  15. Fluorescent molecular rotors : From working principles to visualization of mechanical contacts

    NARCIS (Netherlands)

    Suhina, T.

    2017-01-01

    In this thesis, we develop and characterize a method that enables us to visualize the real microscopic contact area between objects, using fluorescent molecules. Visualization and the ability to predict the real contact area between touching objects is a subject of a considerable interest, because

  16. Fluorescent electrochemistry : towards controlled redox-switching of a single metalloprotein

    NARCIS (Netherlands)

    Akkılıç, Namık

    2013-01-01

    The availability of single-molecule fluorescence detection techniques has brought about a breakthrough in the optical studies of biomolecular properties and functions by enabling the study of molecules one at a time. In this thesis, single-molecule detection is used to obtain detailed information of

  17. Metal Enhanced Fluorescence on Super-Hydrophobic Clusters of Gold Nanoparticles

    KAUST Repository

    Battista, Edmondo

    2016-12-15

    We used optical lithography, electroless deposition and deep reactive ion etching techniques to realize arrays of super-hydrophobic gold nanoparticles arranged in a hierarchical structure. At the micro-scale, silicon-micro pillars in the chip permit to manipulate and concentrate biological solutions, at the nano-scale, gold nanoparticles enable metal enhanced fluorescence (MEF) effects, whereby fluorescence signal of fluorophores in close proximity to a rough metal surface is amplified by orders of magnitude. Here, we demonstrated the device in the analysis of fluorescein derived gold-binding peptides (GBP-FITC). While super-hydrophobic schemes and MEF effects have been heretofore used in isolation, their integration in a platform may advance the current state of fluorescence-based sensing technology in medical diagnostics and biotechnology. This scheme may be employed in protein microarrays where the increased sensitivity of the device may enable the early detection of cancer biomarkers or other proteins of biomedical interest.

  18. Combining imaging with microbiopsy enables a more comprehensive approach for topical drug research (Conference Presentation)

    Science.gov (United States)

    Prow, Tarl W.

    2017-02-01

    Topical drug delivery is a challenging research field, but quantifying topical drug delivery also has significant challenges, especially in the clinical studies. Both cosmeceutical and pharmaceutical endpoints largely drive research in this area. Conventional drug delivery approaches primarily rely on testing trans dermal drug kinetics using excised skin in Franz cells. Thus is a largely unmet need for non- and minimally invasive approaches to evaluate topical drug delivery and efficacy in excised and volunteer skin. We are meeting this need through the development of non-invasive imaging based approaches such as fluorescent dermoscopy, fluorescence scanning and confocal microscopy followed by image analysis. Minimally invasive microbiopsies are being used to extract drug concentrations from tiny pieces of skin without the need for local anaesthetics and without scars. This combined strategy enables us to collect drug disposition information in addition to skin morphology and molecular characterisation which provides a more dynamic and comprehensive way to examine drug deliver, effects of enhancement technologies and efficacy.

  19. Ultraviolet Fluorescence Spectra of Fingerprints

    Directory of Open Access Journals (Sweden)

    Naoki Saitoh

    2005-01-01

    Full Text Available We have studied inherent fluorescence spectra and imaging of fingerprints in the deep ultraviolet (UV region with a nanosecond-pulsed Nd-YAG laser system that consists of a tunable laser, a cooled CCD camera, and a grating spectrometer. In this paper, we have studied UV fluorescence spectra of fingerprints under 266-nm illumination. Fluorescence spectra of fingerprints have two main peaks, around 330 nm (peak A and 440 nm (peak B. At first, when a fingerprint has just been pressed, peak A is dominant. However, its intensity reduces as the total illumination time increases. On the other hand, peak B is weak at first. It appears after enough 266-nm illumination and its intensity increases as time elapses. After 3 h of illumination, peak A almost diminishes and peak B becomes dominant. By leaving the fingerprint under a fluorescent lamp in a room without laser illumination, peak A can be restored partly, while the intensity of peak B still increases.Time-resolved fluorescence spectra were also measured for these two peaks. The lifetime of each peak is 2.0 nsec (peak A and 6.2 nsec (peak B on average. Both peaks seem to consist of several components with different lifetimes. In the case of peak A, the 330-nm peak decays fast and a new component at 360 nm becomes dominant when the delay time exceeds 20 nsec. In the case of peak B, unlike peak A, no clear peak separation is observed, but the peak position seems to move from 440 to 460 nm when the delay time becomes larger.

  20. Principles for Enabling Deep Secondary Design

    DEFF Research Database (Denmark)

    Hansen, Magnus Rotvit Perlt; Pries-Heje, Jan

    and techniques in a hospital. Our analysis of the two cases leads to the identification of four principles of design implementation that primary designers can apply to enable secondary design and four corresponding design implementation principles that secondary designers themselves need to apply.......User-based redesign after implementation has been studied in many contexts gone by many different names, such as appropriation of technology, malleable design and secondary design. The phenomenon of redesigning content has mainly revolved around technologies such as Facebook, Twitter, or Wikipedia...... or portal-based technology with configuration abilities, with very little focus on technologies where users can change both functionality, content and the level of technology complexity. We coin this type of secondary design deep secondary design. In this paper, we investigate how to enable deep secondary...

  1. Femtosecond laser enabled keratoplasty for advanced keratoconus

    Directory of Open Access Journals (Sweden)

    Yathish Shivanna

    2013-01-01

    Full Text Available Purpose : To assess the efficacy and advantages of femtosecond laser enabled keratoplasty (FLEK over conventional penetrating keratoplasty (PKP in advanced keratoconus. Materials and Methods: Detailed review of literature of published randomized controlled trials of operative techniques in PKP and FLEK. Results: Fifteen studies were identified, analyzed, and compared with our outcome. FLEK was found to have better outcome in view of better and earlier stabilization uncorrected visual acuity (UCVA, best corrected visual acuity (BCVA, and better refractive outcomes with low astigmatism as compared with conventional PKP. Wound healing also was noticed to be earlier, enabling early suture removal in FLEK. Conclusions: Studies relating to FLEK have shown better results than conventional PKP, however further studies are needed to assess the safety and intraoperative complications of the procedure.

  2. Femtosecond laser enabled keratoplasty for advanced keratoconus.

    Science.gov (United States)

    Shivanna, Yathish; Nagaraja, Harsha; Kugar, Thungappa; Shetty, Rohit

    2013-08-01

    To assess the efficacy and advantages of femtosecond laser enabled keratoplasty (FLEK) over conventional penetrating keratoplasty (PKP) in advanced keratoconus. Detailed review of literature of published randomized controlled trials of operative techniques in PKP and FLEK. Fifteen studies were identified, analyzed, and compared with our outcome. FLEK was found to have better outcome in view of better and earlier stabilization uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and better refractive outcomes with low astigmatism as compared with conventional PKP. Wound healing also was noticed to be earlier, enabling early suture removal in FLEK. Studies relating to FLEK have shown better results than conventional PKP, however further studies are needed to assess the safety and intraoperative complications of the procedure.

  3. Enabling Automatic Certification of Online Auctions

    Directory of Open Access Journals (Sweden)

    Wei Bai

    2014-04-01

    Full Text Available We consider the problem of building up trust in a network of online auctions by software agents. This requires agents to have a deeper understanding of auction mechanisms and be able to verify desirable properties of a given mechanism. We have shown how these mechanisms can be formalised as semantic web services in OWL-S, a good enough expressive machine-readable formalism enabling software agents, to discover, invoke, and execute a web service. We have also used abstract interpretation to translate the auction's specifications from OWL-S, based on description logic, to COQ, based on typed lambda calculus, in order to enable automatic verification of desirable properties of the auction by the software agents. For this language translation, we have discussed the syntactic transformation as well as the semantics connections between both concrete and abstract domains. This work contributes to the implementation of the vision of agent-mediated e-commerce systems.

  4. Enabling Sustainable Improvement in IT Entrepreneurship

    Directory of Open Access Journals (Sweden)

    Paul E. Renaud

    2013-06-01

    Full Text Available Firms must embrace processes that enable the information technology (IT function to become a strategic partner to the business functions it serves. Process ambidexterity is a way for processes to be augmented to improve alignment and adaptability to new markets and technologies. By applying the principles of process ambidexterity, the key elements required for sustainable change within the capabilities that comprise the IT function of the firm are identified. Furthermore, the scope and depth of the dysfunction that is widespread across large firms that depend upon IT are outlined to provide a contextual basis for presenting a solution framework to address sustainable change. This framework for sustainable change is of primary benefit to IT executives seeking to systematically transform the IT function and enable IT entrepreneurship.

  5. Enabling international adoption of LOINC through translation

    Science.gov (United States)

    Vreeman, Daniel J.; Chiaravalloti, Maria Teresa; Hook, John; McDonald, Clement J.

    2012-01-01

    Interoperable health information exchange depends on adoption of terminology standards, but international use of such standards can be challenging because of language differences between local concept names and the standard terminology. To address this important barrier, we describe the evolution of an efficient process for constructing translations of LOINC terms names, the foreign language functions in RELMA, and the current state of translations in LOINC. We also present the development of the Italian translation to illustrate how translation is enabling adoption in international contexts. We built a tool that finds the unique list of LOINC Parts that make up a given set of LOINC terms. This list enables translation of smaller pieces like the core component “hepatitis c virus” separately from all the suffixes that could appear with it, such “Ab.IgG”, “DNA”, and “RNA”. We built another tool that generates a translation of a full LOINC name from all of these atomic pieces. As of version 2.36 (June 2011), LOINC terms have been translated into 9 languages from 15 linguistic variants other than its native English. The five largest linguistic variants have all used the Part-based translation mechanism. However, even with efficient tools and processes, translation of standard terminology is a complex undertaking. Two of the prominent linguistic challenges that translators have faced include: the approach to handling acronyms and abbreviations, and the differences in linguistic syntax (e.g. word order) between languages. LOINC’s open and customizable approach has enabled many different groups to create translations that met their needs and matched their resources. Distributing the standard and its many language translations at no cost worldwide accelerates LOINC adoption globally, and is an important enabler of interoperable health information exchange PMID:22285984

  6. GPS Enabled Semi-Autonomous Robot

    Science.gov (United States)

    2017-09-01

    AUTONOMOUS ROBOT by Connor F. Bench September 2017 Thesis Advisor: Xiaoping Yun Second Reader: James Calusdian THIS PAGE INTENTIONALLY...AND SUBTITLE GPS ENABLED SEMI-AUTONOMOUS ROBOT 5. FUNDING NUMBERS 6. AUTHOR(S) Connor F. Bench 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...objective of this research is to integrate GPS and local sensory data to allow a robot to operate semi-autonomously outside of a laboratory environment

  7. Enabling Persistent Peace After Negotiated Settlements

    Science.gov (United States)

    2016-12-01

    ENABLING PERSISTENT PEACE AFTER NEGOTIATED SETTLEMENTS Evert Andres Mejia Lieutenant Colonel, Colombian Marines B.S., Escuela Naval de Cadetes, 2004...simply as “La Violencia .” On April 9, 1948, in the midst of the struggle between the main Colombian liberal and conservative political parties, the...traditional order.”157 “La Violencia ” period between 1948 and 1958 was one of the bloodiest periods in Colombian history,158 characterized by assassinations

  8. Femtosecond laser enabled keratoplasty for advanced keratoconus

    OpenAIRE

    Yathish Shivanna; Harsha Nagaraja; Thungappa Kugar; Rohit Shetty

    2013-01-01

    Purpose : To assess the efficacy and advantages of femtosecond laser enabled keratoplasty (FLEK) over conventional penetrating keratoplasty (PKP) in advanced keratoconus. Materials and Methods: Detailed review of literature of published randomized controlled trials of operative techniques in PKP and FLEK. Results: Fifteen studies were identified, analyzed, and compared with our outcome. FLEK was found to have better outcome in view of better and earlier stabilization uncorrected visual acuity...

  9. IT Enabled Agility in Organizational Ambidexterity

    OpenAIRE

    Röder, Nina; Schermann, Michael; Krcmar, Helmut

    2015-01-01

    The aim of ambidextrous organizations is to balance exploratory and exploitative learning concepts. They innovate through experiments and research, and capture the value of innovations through refinement and continuous improvement. In this paper, we study the relationship of organizational ambidexterity and IT enabled agility. Based on a case study with a German car manufacturer we find that (1) entrepreneurial agility impedes exploitative concepts, (2) adaptive agility impedes exploratory co...

  10. Smart Sensors Enable Smart Air Conditioning Control

    OpenAIRE

    Cheng, Chin-Chi; Lee, Dasheng

    2014-01-01

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants’ information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans’ intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be contr...

  11. Enabling international adoption of LOINC through translation.

    Science.gov (United States)

    Vreeman, Daniel J; Chiaravalloti, Maria Teresa; Hook, John; McDonald, Clement J

    2012-08-01

    Interoperable health information exchange depends on adoption of terminology standards, but international use of such standards can be challenging because of language differences between local concept names and the standard terminology. To address this important barrier, we describe the evolution of an efficient process for constructing translations of LOINC terms names, the foreign language functions in RELMA, and the current state of translations in LOINC. We also present the development of the Italian translation to illustrate how translation is enabling adoption in international contexts. We built a tool that finds the unique list of LOINC Parts that make up a given set of LOINC terms. This list enables translation of smaller pieces like the core component "hepatitis c virus" separately from all the suffixes that could appear with it, such "Ab.IgG", "DNA", and "RNA". We built another tool that generates a translation of a full LOINC name from all of these atomic pieces. As of version 2.36 (June 2011), LOINC terms have been translated into nine languages from 15 linguistic variants other than its native English. The five largest linguistic variants have all used the Part-based translation mechanism. However, even with efficient tools and processes, translation of standard terminology is a complex undertaking. Two of the prominent linguistic challenges that translators have faced include: the approach to handling acronyms and abbreviations, and the differences in linguistic syntax (e.g. word order) between languages. LOINC's open and customizable approach has enabled many different groups to create translations that met their needs and matched their resources. Distributing the standard and its many language translations at no cost worldwide accelerates LOINC adoption globally, and is an important enabler of interoperable health information exchange. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Conference on Enabling Teachers for Entrepreneurship Education

    OpenAIRE

    Silva, Maria do Carmo Vieira da; Reis, Carlos; Pereira, Cristina; Formosinho, Dores; Ferreira, Eduarda; Hoare, Malcolm; Tadeu, Pedro; Gonçalves, Teresa; Paiva, Teresa; Fernández Cruz, Manuel; Afonso, Maria Margarida; Gijón Puerta, José

    2013-01-01

    The Conference on Enabling Teachers for Entrepreneurship Education (ENTENP2013) in Initial Teacher Education (ITE) will be held at the Guarda Polytechnic Institute (GPI) in Guarda on 7/8 June 2013. We expect delegates from all the Portuguese Higher Education Institutions and the EU Member States, as well as Pre-Accession Countries and countries participating in the Competitiveness and Innovation Framework Programme (CIP). ENTENP 2013 addresses to all practitioners from the area of teacher edu...

  13. Optofluidic fluorescent imaging cytometry on a cell phone.

    Science.gov (United States)

    Zhu, Hongying; Mavandadi, Sam; Coskun, Ahmet F; Yaglidere, Oguzhan; Ozcan, Aydogan

    2011-09-01

    Fluorescent microscopy and flow cytometry are widely used tools in biomedical sciences. Cost-effective translation of these technologies to remote and resource-limited environments could create new opportunities especially for telemedicine applications. Toward this direction, here we demonstrate the integration of imaging cytometry and fluorescent microscopy on a cell phone using a compact, lightweight, and cost-effective optofluidic attachment. In this cell-phone-based optofluidic imaging cytometry platform, fluorescently labeled particles or cells of interest are continuously delivered to our imaging volume through a disposable microfluidic channel that is positioned above the existing camera unit of the cell phone. The same microfluidic device also acts as a multilayered optofluidic waveguide and efficiently guides our excitation light, which is butt-coupled from the side facets of our microfluidic channel using inexpensive light-emitting diodes. Since the excitation of the sample volume occurs through guided waves that propagate perpendicular to the detection path, our cell-phone camera can record fluorescent movies of the specimens as they are flowing through the microchannel. The digital frames of these fluorescent movies are then rapidly processed to quantify the count and the density of the labeled particles/cells within the target solution of interest. We tested the performance of our cell-phone-based imaging cytometer by measuring the density of white blood cells in human blood samples, which provided a decent match to a commercially available hematology analyzer. We further characterized the imaging quality of the same platform to demonstrate a spatial resolution of ~2 μm. This cell-phone-enabled optofluidic imaging flow cytometer could especially be useful for rapid and sensitive imaging of bodily fluids for conducting various cell counts (e.g., toward monitoring of HIV+ patients) or rare cell analysis as well as for screening of water quality in

  14. On-chip cell analysis platform: Implementation of contact fluorescence microscopy in microfluidic chips

    Science.gov (United States)

    Takehara, Hiroaki; Kazutaka, Osawa; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2017-09-01

    Although fluorescence microscopy is the gold standard tool for biomedical research and clinical applications, their use beyond well-established laboratory infrastructures remains limited. The present study investigated a novel on-chip cell analysis platform based on contact fluorescence microscopy and microfluidics. Combined use of a contact fluorescence imager based on complementary metal-oxide semiconductor technology and an ultra-thin glass bottom microfluidic chip enabled both to observe living cells with minimal image distortion and to ease controlling and handling of biological samples (e.g. cells and biological molecules) in the imaged area. A proof-of-concept experiment of on-chip detection of cellular response to endothelial growth factor demonstrated promising use for the recently developed on-chip cell analysis platform. Contact fluorescence microscopy has numerous desirable features including compatibility with plastic microfluidic chips and compatibility with the electrical control system, and thus will fulfill the requirements of a fully automated cell analysis system.

  15. Accuracy of fluorescent tomography in the presence of heterogeneities: study of the normalized Born ratio.

    Science.gov (United States)

    Soubret, Antoine; Ripoll, Jorge; Ntziachristos, Vasilis

    2005-10-01

    We studied the performance of three-dimensional fluorescence tomography of diffuse media in the presence of heterogeneities. Experimental measurements were acquired using an imaging system consisting of a parallel plate-imaging chamber and a lens coupled charge coupled device camera, which enables conventional planar imaging as well as fluorescence tomography. To simulate increasing levels of background heterogeneity, we employed phantoms made of a fluorescent tube surrounded by several absorbers in different combinations of absorption distribution. We also investigated the effect of low absorbing thin layers (such as membranes). We show that the normalized Born approach accurately retrieves the position and shape of the fluorochrome even at high background heterogeneity. We also demonstrate that the quantification is relatively insensitive to a varying degree of heterogeneity and background optical properties. Findings are further contrasted to images obtained with the standard Born expansion and with a normalized approach that divides the fluorescent field with excitation measurements through a homogeneous medium.

  16. Ratiometric fluorescence detection of an anthrax biomarker with Eu3+-chelated chitosan biopolymers.

    Science.gov (United States)

    Donmez, Mert; Oktem, Huseyin Avni; Yilmaz, M Deniz

    2018-01-15

    A novel chitosan-based ratiometric fluorescent probe incorporating an EDTA-Eu3+ complex as the sensing unit and fluorescein dye as the internal standard was designed to detect dipicolinic acid (DPA) as an anthrax biomarker with high sensitivity and selectivity. The fluorescence intensity of fluorescein dye attached to the chitosan backbone remains constant as an internal reference, while the Eu3+ emission increased linearly upon the consecutive addition of DPA. The selectivity studies were performed by adding different competitive aromatic ligands to the sensing environment and no signifacant fluorescence response was observed. The results demonstrated the superior selectivity of the system to DPA. Overall, this novel chitosan-based ratiometric fluorescent probe enables ratiometric and sensitive DPA detection over nanomolar concentrations (as low as 10nM) and displays straightforward selectivity over other competitive aromatic ligands. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Deep-brain imaging via epi-fluorescence Computational Cannula Microscopy

    Science.gov (United States)

    Kim, Ganghun; Nagarajan, Naveen; Pastuzyn, Elissa; Jenks, Kyle; Capecchi, Mario; Shepherd, Jason; Menon, Rajesh

    2017-03-01

    Here we demonstrate widefield (field diameter = 200 μm) fluorescence microscopy and video imaging inside the rodent brain at a depth of 2 mm using a simple surgical glass needle (cannula) of diameter 0.22 mm as the primary optical element. The cannula guides excitation light into the brain and the fluorescence signal out of the brain. Concomitant image-processing algorithms are utilized to convert the spatially scrambled images into fluorescent images and video. The small size of the cannula enables minimally invasive imaging, while the long length (>2 mm) allow for deep-brain imaging with no additional complexity in the optical system. Since no scanning is involved, widefield fluorescence video at the native frame rate of the camera can be achieved.

  18. Fluorescent detection of single tracks of alpha particles using lithium fluoride crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bilski, P., E-mail: pawel.bilski@ifj.edu.pl; Marczewska, B.

    2017-02-01

    Lithium fluoride single crystals were successfully used for fluorescent imaging of single tracks of alpha particles. This was realized with a standard wide-field fluorescent microscope equipped with a 100× objective. Alpha particles create F{sub 2} and F{sub 3}{sup +} color centers in LiF crystals. The subsequent illumination with the blue light (wavelength around 445 nm), excites these centers and produces fluorescence with a broad band peaked at 670 nm. The observed tracks of alpha particles have diameter of about 500 nm. Focusing of the microscope at different depths in a LiF crystal, enables imaging changes of shape and position of tracks, allowing for visualization of their paths. These encouraging results are the first step towards practical application of LiF as fluorescent nuclear track detectors.

  19. Chlorophyll induced fluorescence retrieved from GOME2 for improving gross primary productivity estimates of vegetation

    Science.gov (United States)

    van Leth, Thomas C.; Verstraeten, Willem W.; Sanders, Abram F. J.

    2014-05-01

    Mapping terrestrial chlorophyll fluorescence is a crucial activity to obtain information on the functional status of vegetation and to improve estimates of light-use efficiency (LUE) and global primary productivity (GPP). GPP quantifies carbon fixation by plant ecosystems and is therefore an important parameter for budgeting terrestrial carbon cycles. Satellite remote sensing offers an excellent tool for investigating GPP in a spatially explicit fashion across different scales of observation. The GPP estimates, however, still remain largely uncertain due to biotic and abiotic factors that influence plant production. Sun-induced fluorescence has the ability to enhance our knowledge on how environmentally induced changes affect the LUE. This can be linked to optical derived remote sensing parameters thereby reducing the uncertainty in GPP estimates. Satellite measurements provide a relatively new perspective on global sun-induced fluorescence, enabling us to quantify spatial distributions and changes over time. Techniques have recently been developed to retrieve fluorescence emissions from hyperspectral satellite measurements. We use data from the Global Ozone Monitoring Instrument 2 (GOME2) to infer terrestrial fluorescence. The spectral signatures of three basic components atmospheric: absorption, surface reflectance, and fluorescence radiance are separated using reference measurements of non-fluorescent surfaces (desserts, deep oceans and ice) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach is applied similar to that of Joiner et al. (2013, ACP). Here we show our first global maps of the GOME2 retrievals of chlorophyll fluorescence. First results indicate fluorescence distributions that are similar with that obtained by GOSAT and GOME2 as reported by Joiner et al. (2013, ACP), although we find slightly higher values. In view of optimizing the fluorescence retrieval, we will show the effect of the references

  20. Fluorescent Protein Approaches in Alpha Herpesvirus Research

    Directory of Open Access Journals (Sweden)

    Ian B. Hogue

    2015-11-01

    Full Text Available In the nearly two decades since the popularization of green fluorescent protein (GFP, fluorescent protein-based methodologies have revolutionized molecular and cell biology, allowing us to literally see biological processes as never before. Naturally, this revolution has extended to virology in general, and to the study of alpha herpesviruses in particular. In this review, we provide a compendium of reported fluorescent protein fusions to herpes simplex virus 1 (HSV-1 and pseudorabies virus (PRV structural proteins, discuss the underappreciated challenges of fluorescent protein-based approaches in the context of a replicating virus, and describe general strategies and best practices for creating new fluorescent fusions. We compare fluorescent protein methods to alternative approaches, and review two instructive examples of the caveats associated with fluorescent protein fusions, including describing several improved fluorescent capsid fusions in PRV. Finally, we present our future perspectives on the types of powerful experiments these tools now offer.

  1. Fluorescent Protein Approaches in Alpha Herpesvirus Research

    Science.gov (United States)

    Hogue, Ian B.; Bosse, Jens B.; Engel, Esteban A.; Scherer, Julian; Hu, Jiun-Ruey; del Rio, Tony; Enquist, Lynn W.

    2015-01-01

    In the nearly two decades since the popularization of green fluorescent protein (GFP), fluorescent protein-based methodologies have revolutionized molecular and cell biology, allowing us to literally see biological processes as never before. Naturally, this revolution has extended to virology in general, and to the study of alpha herpesviruses in particular. In this review, we provide a compendium of reported fluorescent protein fusions to herpes simplex virus 1 (HSV-1) and pseudorabies virus (PRV) structural proteins, discuss the underappreciated challenges of fluorescent protein-based approaches in the context of a replicating virus, and describe general strategies and best practices for creating new fluorescent fusions. We compare fluorescent protein methods to alternative approaches, and review two instructive examples of the caveats associated with fluorescent protein fusions, including describing several improved fluorescent capsid fusions in PRV. Finally, we present our future perspectives on the types of powerful experiments these tools now offer. PMID:26610544

  2. Preparation and Application of Fluorescent Carbon Dots

    National Research Council Canada - National Science Library

    Zuo, Jun; Jiang, Tao; Zhao, Xiaojing; Xiong, Xiaohong; Xiao, Saijin; Zhu, Zhiqiang

    2015-01-01

      Fluorescent carbon dots (CDs) are a novel type of fluorescent nanomaterials, which not only possess the specific quantum confinement effects of nanomaterials due to the small size of nanomaterials, but also have good...

  3. Preparation and Application of Fluorescent Carbon Dots

    Directory of Open Access Journals (Sweden)

    Jun Zuo

    2015-01-01

    Full Text Available Fluorescent carbon dots (CDs are a novel type of fluorescent nanomaterials, which not only possess the specific quantum confinement effects of nanomaterials due to the small size of nanomaterials, but also have good biocompatibility and high fluorescence. Meanwhile, fluorescence CDs overcome the shortcomings of high toxicity of traditional nanomaterials. Moreover, the preparation procedure of fluorescent CDs is simple and easy. Therefore, fluorescent CDs have great potential applied in photocatalysis, biochemical sensing, bioimaging, drug delivery, and other related areas. In this paper, recent hot researches on fluorescent CDs are reviewed and some problems in the progress of fluorescent CDs are also summarized. At last, a future outlook in this direction is presented.

  4. Optical fiber fluorescence spectroscopy for detecting AFM1 in milk

    Science.gov (United States)

    Mignani, A. G.; Cucci, C.; Ciaccheri, L.; Dall'Asta, C.; Galaverna, G.; Dossena, A.; Marchelli, R.

    2008-04-01

    Fluorescence spectroscopy carried out by means of optical fibers was used for the rapid screening of M1 aflatoxin in milk, enabling the detection of concentrations up to the legal limit, which is 50 ppt. A compact fluorometric device equipped with a LED source, a miniaturized spectrometer, and optical fibers for illumination/detection of the measuring micro-cell was tested for measuring threshold values of AFM1 in pre-treated milk samples. Multivariate processing of the spectral data made it possible to obtain a preliminary screening at the earlier stages of the industrial process, as well as to discard contaminated milk stocks before their inclusion in the production chain.

  5. Electromagnetic fields emitted by fluorescent and compact fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.; Sebastiao, D.; Ladeira, D.; Carpinteiro, G.; Antunes, M.; Correia, L.M.; Fernandes, C. [Instituto de Telecomunicacoes, Instituto Superior Tecnico, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal)

    2009-05-15

    In the scope of the monIT Project, it was found that fluorescent and compact fluorescent lamps are also important sources of radiation. More than increasing electromagnetic field (EMF) levels in a particular environment, the radiated EMFs from ballasts may cause interference in other devices. Two different lamps are analysed, both in terms of their radiated frequency spectrum and of their compliance with European EMF recommended exposure levels. As expected, the analysis of results shows that, in the immediate vicinity of a lamp, EMF levels radiated by lighting devices depend on the lamp power. Finally, one can conclude that EMFs radiated from both lamps are in compliance with the EMF reference levels. (author)

  6. Entangled-photon coincidence fluorescence imaging.

    Science.gov (United States)

    Scarcelli, Giuliano; Yun, Seok H

    2008-09-29

    We describe fluorescence imaging using the second-order correlation of entangled photon pairs. The proposed method is based on the principle that one photon of the pair carries information on where the other photon has been absorbed and has produced fluorescence in a sample. Because fluorescent molecules serve as "detectors" breaking the entanglement, multiply-scattered fluorescence photons within the sample do not cause image blur. We discuss experimental implementations.

  7. Development of Fluorescent Probes that Target Serotonin 5-HT2B Receptors.

    Science.gov (United States)

    Azuaje, Jhonny; López, Paula; Iglesias, Alba; de la Fuente, Rocío A; Pérez-Rubio, José M; García, Diego; Stępniewski, Tomasz Maciej; García-Mera, Xerardo; Brea, José M; Selent, Jana; Pérez, Dolores; Castro, Marián; Loza, María I; Sotelo, Eddy

    2017-09-07

    Some 5-HT2B fluorescent probes were obtained by tagging 1-(2,5-dimethoxy-4-iodophenyl)-propan-2-amine (DOI) with a subset of fluorescent amines. Some of the resulting fluorescent ligands showed excellent affinity and selectivity profiles at the 5-HT2B receptors (e.g. 12b), while retain the agonistic functional behaviour of the model ligand (DOI). The study highlighted the most salient features of the structure-activity relationship in this series and these were substantiated by a molecular modelling study based on a receptor-driven docking model constructed on the basis of the crystal structure of the human 5-HT2B receptor. One of the fluorescent ligands developed in this work, compound 12i, specifically labelled CHO-K1 cells expressing 5-HT2B receptors and not parental CHO-K1 cells in a concentration-dependent manner. 12i enables imaging and quantification of specific 5-HT2B receptor labelling in live cells by automated fluorescence microscopy as well as quantification by measurements of fluorescence intensity using a fluorescence plate reader.

  8. Web-enabling technologies for the factory floor: a web-enabling strategy for emanufacturing

    Science.gov (United States)

    Velez, Ricardo; Lastra, Jose L. M.; Tuokko, Reijo O.

    2001-10-01

    This paper is intended to address the different technologies available for Web-enabling of the factory floor. It will give an overview of the importance of Web-enabling of the factory floor, in the application of the concepts of flexible and intelligent manufacturing, in conjunction with e-commerce. As a last section, it will try to define a Web-enabling strategy for the application in eManufacturing. This is made under the scope of the electronics manufacturing industry, so every application, technology or related matter is presented under such scope.

  9. Demonstrating Fluorescence with Neon Paper and Plastic

    Science.gov (United States)

    Birriel, Jennifer J.; Roe, Clarissa

    2015-01-01

    Several papers in this journal have dealt with the fluorescence in orange neon plastic, olive oil, and soda. In each case, the fluorescent emission was excited by either green or violet-blue laser light. In this paper, we examine the fluorescent emission spectra of so-called neon colored papers and plastic clipboards available in department and…

  10. Total Internal Reflection Fluorescence Microscopy Imaging-Guided Confocal Single-Molecule Fluorescence Spectroscopy

    OpenAIRE

    Zheng, Desheng; Kaldaras, Leonora; Lu, H. Peter

    2013-01-01

    We have developed an integrated spectroscopy system combining total internal reflection fluorescence microscopy imaging with confocal single-molecule fluorescence spectroscopy for two-dimensional interfaces. This spectroscopy approach is capable of both multiple molecules simultaneously sampling and in situ confocal fluorescence dynamics analyses of individual molecules of interest. We have demonstrated the calibration with fluorescent microspheres, and carried out single-molecule spectroscop...

  11. ATP Changes the Fluorescence Lifetime of Cyan Fluorescent protein via an Interaction with His148

    NARCIS (Netherlands)

    Borst, J.W.; Willemse, M.; Slijkhuis, R.; Krogt, G.; Laptenok, S.; Jalink, K.; Wieringa, B.; Fransen, J.A.M.

    2010-01-01

    Recently, we described that ATP induces changes in YFP/CFP fluorescence intensities of Fluorescence Resonance Energy Transfer (FRET) sensors based on CFP-YFP. To get insight into this phenomenon, we employed fluorescence lifetime spectroscopy to analyze the influence of ATP on these fluorescent

  12. ATP changes the fluorescence lifetime of cyan fluorescent protein via an interaction with His148.

    NARCIS (Netherlands)

    Borst, J.W.; Willemse, M.P.; Slijkhuis, R.; Krogt, G. van der; Laptenok, S.P.; Jalink, K.; Wieringa, B.; Fransen, J.A.M.

    2010-01-01

    Recently, we described that ATP induces changes in YFP/CFP fluorescence intensities of Fluorescence Resonance Energy Transfer (FRET) sensors based on CFP-YFP. To get insight into this phenomenon, we employed fluorescence lifetime spectroscopy to analyze the influence of ATP on these fluorescent

  13. Imaging Ca2+ with a Fluorescent Rhodol.

    Science.gov (United States)

    Contractor, Alisha A; Miller, Evan W

    2018-01-16

    Ca2+ mediates a host of biochemical and biophysical signaling processes in cells. The development of synthetic, Ca2+-sensitive fluorophores has played an instrumental role in our understanding of the temporal and spatial dynamics of Ca2+. Coupling Ca2+-selective ligands to fluorescent reporters has provided a wealth of excellent indicators that span the visible excitation and emission spectrum and possess Ca2+ affinities suited to a variety of cellular contexts. One underdeveloped area is the use of hybrid rhodamine/fluorescein fluorophores, or rhodols, in the context of Ca2+ sensing. Rhodols are bright and photostable and have good two-photon absorption cross sections (σTPA), making them excellent candidates for incorporation into Ca2+-sensing scaffolds. Here, we present the design, synthesis, and application of rhodol Ca2+ sensor 1 (RCS-1), a chlorinated pyrrolidine-based rhodol. RCS-1 possesses a Ca2+ binding constant of 240 nM and a 10-fold turn response to Ca2+. RCS-1 effectively absorbs infrared light and has a σTPA of 76 GM at 840 nm, 3-fold greater than that of its fluorescein-based counterpart. The acetoxy-methyl ester of RCS-1 stains the cytosol of live cells, enabling observation of Ca2+ fluctuations and cultured neurons using both one- and two-photon illumination. Together, these results demonstrate the utility of rhodol-based scaffolds for Ca2+ sensing using two-photon illumination in neurons.

  14. A two-photon fluorescent probe for ratiometric imaging of endogenous hypochlorous acid in live cells and tissues.

    Science.gov (United States)

    Jun, Yong Woong; Sarkar, Sourav; Singha, Subhankar; Reo, Ye Jin; Kim, Hye Rim; Kim, Jong-Jin; Chang, Young-Tae; Ahn, Kyo Han

    2017-09-28

    A fluorescent probe that enables ratiometric imaging of endogenous hypochlorous acid (HOCl) in cells and tissues by two-photon microscopy is developed based on a red-emitting acetyl-benzocoumarin (AcBC) dye. An oxathiolane group in the probe reacts with HOCl to generate the AcBC dye, which involves a ratiometric fluorescence change only toward HOCl along with high sensitivity.

  15. Laser-induced fluorescence imaging of subsurface tissue structures with a volume holographic spatial-spectral imaging system.

    Science.gov (United States)

    Luo, Yuan; Gelsinger-Austin, Paul J; Watson, Jonathan M; Barbastathis, George; Barton, Jennifer K; Kostuk, Raymond K

    2008-09-15

    A three-dimensional imaging system incorporating multiplexed holographic gratings to visualize fluorescence tissue structures is presented. Holographic gratings formed in volume recording materials such as a phenanthrenquinone poly(methyl methacrylate) photopolymer have narrowband angular and spectral transmittance filtering properties that enable obtaining spatial-spectral information within an object. We demonstrate this imaging system's ability to obtain multiple depth-resolved fluorescence images simultaneously.

  16. Sorting fluorescent nanocrystals with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Gerion, Daniele; Parak, Wolfgang J.; Williams, Shara C.; Zanchet, Daniela; Micheel, Christine M.; Alivisatos, A. Paul

    2001-12-10

    Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle using hybridization on a defined micrometer -size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals towards specific biological targets and detecting them, combined with their superior photo-stability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.

  17. Fluorescence spectroscopy for neoplasms control

    Science.gov (United States)

    Bratchenko, I. A.; Kristoforova, Yu. A.; Myakinin, O. O.; Artemyev, D. N.; Kozlov, S. V.; Moryatov, A. A.; Zakharov, V. P.

    2016-04-01

    Investigation of malignant skin tumors diagnosis was performed involving two setups for native tissues fluorescence control in visible and near infrared regions. Combined fluorescence analysis for skin malignant melanomas and basal cell carcinomas was performed. Autofluorescence spectra of normal skin and oncological pathologies stimulated by 457 nm and 785 nm lasers were registered for 74 skin tissue samples. Spectra of 10 melanomas and 27 basal cell carcinomas were registered ex vivo. Skin tumors analysis was made on the basis of autofluorescence spectra intensity and curvature for analysis of porphyrins, lipo-pigments, flavins and melanin. Separation of melanomas and basal cell carcinomas was performed on the basis of discriminant analysis. Overall accuracy of basal cell carcinomas and malignant melanomas separation in current study reached 86.5% with 70% sensitivity and 92.6% specificity.

  18. Correlative fluorescence and electron microscopy.

    Science.gov (United States)

    Schirra, Randall T; Zhang, Peijun

    2014-10-01

    Correlative fluorescence and electron microscopy (CFEM) is a multimodal technique that combines dynamic and localization information from fluorescence methods with ultrastructural data from electron microscopy, to give new information about how cellular components change relative to the spatiotemporal dynamics within their environment. In this review, we will discuss some of the basic techniques and tools of the trade for utilizing this attractive research method, which is becoming a very powerful tool for biology labs. The information obtained from correlative methods has proven to be invaluable in creating consensus between the two types of microscopy, extending the capability of each, and cutting the time and expense associated with using each method separately for comparative analysis. The realization of the advantages of these methods in cell biology has led to rapid improvement in the protocols and has ushered in a new generation of instruments to reach the next level of correlation--integration. Copyright © 2014 John Wiley & Sons, Inc.

  19. Fluorescence imaging agents in cancerology.

    Science.gov (United States)

    Paganin-Gioanni, Aurélie; Bellard, Elisabeth; Paquereau, Laurent; Ecochard, Vincent; Golzio, Muriel; Teissié, Justin

    2010-09-01

    One of the major challenges in cancer therapy is to improve early detection and prevention using novel targeted cancer diagnostics. Detection requests specific recognition. Tumor markers have to be ideally present on the surface of cancer cells. Their targeting with ligands coupled to imaging agents make them visible/detectable. Fluorescence imaging is a newly emerging technology which is becoming a complementary medical method for cancer diagnosis. It allows detection with a high spatio-temporal resolution of tumor markers in small animals and in clinical studies. In this review, we focus on the recent outcome of basic studies in the design of new approaches (probes and devices) used to detect tumor cells by fluorescence imaging.

  20. A Wireless Sensor Enabled by Wireless Power

    Science.gov (United States)

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-01-01

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network. PMID:23443370

  1. Identifying enabling management practices for employee engagement

    Directory of Open Access Journals (Sweden)

    Marius Joubert

    2011-12-01

    Full Text Available Orientation: A currently emerging viewpoint is that today's management practices no longer add value to organisations. The focus of this article is to conduct a systematic review of the scholarly literature on management practices that could be related to employee engagement. Research purpose: This study searched for evidence in support of the notion of a management value chain, and enabling management practices within each value chain component that could relate to employee engagement. Motivation for the study: An alternative management value chain model could contribute towards a better understanding of which management practices may potentially impact employee engagement. Research design, approach, and method: This is a non-empirical (theoretical study, based on a systematic, in-depth literature review to identify the key management components and enabling practices within this proposed management value chain. Scholarly research databases were sourced for relevant peer reviewed research conducted since 1990, not excluding important contributions prior to 1990. The literature was systematically searched, selected, studied, and contextualized within this study. Main findings: Support was found for the notion of a management value chain, for enabling management practices within each proposed management value chain component, and it was also established these management practices indeed have an impact on employee engagement. Practical/managerial/implications: The possibility that management work can be presented as a generic management value chain allows managers to approach engaging management practices more systematically. Contribution/value-add: This study highlights the importance of some management practices that have never been seen as part of management work.

  2. Product Line Enabled Intelligent Mobile Middleware

    DEFF Research Database (Denmark)

    Zhang, Weishan; Kunz, Thomas; Hansen, Klaus Marius

    2007-01-01

    research project called PLIMM that focuses on user-centered application scenarios. PLIMM is designed based on software product line ideas which make it possible for specialized customization and optimization for different purposes and hardware/software platforms. To enable intelligence, the middleware...... needs access to a range of context models. We model these contexts with OWL, focusing on user-centered concepts. The basic building block of PLIMM is the enhanced BDI agent where OWL context ontology logic reasoning will add indirect beliefs to the belief sets. Our approach also addresses the handling...

  3. System for RFID-Enabled Information Collection

    Science.gov (United States)

    Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Kennedy, Timothy F. (Inventor); Ngo, Phong H. (Inventor)

    2017-01-01

    A sensor and system provide for radio frequency identification (RFID)-enabled information collection. The sensor includes a ring-shaped element and an antenna. The ring-shaped element includes a conductive ring and an RFID integrated circuit. The antenna is spaced apart from the ring-shaped element and defines an electrically-conductive path commensurate in size and shape to at least a portion of the conductive ring. The system may include an interrogator for energizing the ring-shaped element and receiving a data transmission from the RFID integrated circuit that has been energized for further processing by a processor.

  4. Checkpoint/restart-enabled parallel debugging

    Energy Technology Data Exchange (ETDEWEB)

    Hursey, Joshua [Indiana Univ., Bloomington, IN (United States); January, Chris [Allinea Software Ltd., Warwick (United Kingdom); O' Connor, Mark [Allinea Software Ltd., Warwick (United Kingdom); Hargrove, Paul H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lecomber, David [Allinea Software Ltd., Warwick (United Kingdom); Squyres, Jeffrey M. [Cisco Systems, Inc., San Jose, CA (United States); Lumsdaine, Andrew [Indiana Univ., Bloomington, IN (United States)

    2010-11-12

    Debugging is often the most time consuming part of software development. HPC applications prolong the debugging process by adding more processes interacting in dynamic ways for longer periods of time. Checkpoint/restart- enabled parallel debugging returns the developer to an intermediate state closer to the bug. This focuses the debugging process, saving developers considerable amounts of time, but requires parallel debuggers cooperating with MPI implementations and checkpointers. This paper presents a design specification for such a cooperative relationship. Additionally, this paper discusses the application of this design to the GDB and DDT debuggers, Open MPI, and BLCR projects. © 2010 Springer-Verlag.

  5. Principles for enabling deep secondary design

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Hansen, Magnus Rotvit Perlt

    2017-01-01

    design by analyzing two cases where secondary designers fundamentally change functionality, content and technology complexity level. The first case redesigns a decision model for agile development in an insurance company; the second creates a contingency model for choosing project management tools...... and techniques in a hospital. Our analysis of the two cases leads to the identification of four principles of design implementation that primary designers can apply to enable secondary design and four corresponding design implementation principles that secondary designers themselves need to apply....

  6. Flexibility-enabling Contracts in Electricity Markets

    DEFF Research Database (Denmark)

    Boscan, Luis; Poudineh, Rahmatallah

    power systems. However, due to presence of high transaction costs, relative to the size of resource, the emerging small resources cannot directly participate in an organised electricity market and/or compete. This paper asks the fundamental question of how should the provision of flexibility, as a multi....... Additionally, along with traditional sources, which already enable flexibility, a number of business models, such as thermostat-based demand response, aggregators and small storage providers, are emerging in electricity markets and expected to constitute important sources of flexibility in future decentralised...

  7. PHM Enabled Autonomous Propellant Loading Operations

    Science.gov (United States)

    Walker, Mark; Figueroa, Fernando

    2017-01-01

    The utility of Prognostics and Health Management (PHM) software capability applied to Autonomous Operations (AO) remains an active research area within aerospace applications. The ability to gain insight into which assets and subsystems are functioning properly, along with the derivation of confident predictions concerning future ability, reliability, and availability, are important enablers for making sound mission planning decisions. When coupled with software that fully supports mission planning and execution, an integrated solution can be developed that leverages state assessment and estimation for the purposes of delivering autonomous operations. The authors have been applying this integrated, model-based approach to the autonomous loading of cryogenic spacecraft propellants at Kennedy Space Center.

  8. Camera-enabled techniques for organic synthesis

    Science.gov (United States)

    Ingham, Richard J; O’Brien, Matthew; Browne, Duncan L

    2013-01-01

    Summary A great deal of time is spent within synthetic chemistry laboratories on non-value-adding activities such as sample preparation and work-up operations, and labour intensive activities such as extended periods of continued data collection. Using digital cameras connected to computer vision algorithms, camera-enabled apparatus can perform some of these processes in an automated fashion, allowing skilled chemists to spend their time more productively. In this review we describe recent advances in this field of chemical synthesis and discuss how they will lead to advanced synthesis laboratories of the future. PMID:23766820

  9. Fluorescent compounds present in food

    OpenAIRE

    Soto Serrano, Axel

    2014-01-01

    Póster The food industry demands fast, reliable, cheap and reproducible methods for quality and process control. This bibliographic review work investigates florescence spectroscopy, a method that couldn’t be used in food until the recent technological advances, concretely front-face fluorescence and chemometric tools. This technology presents advantages as compared to classical methods like HPLC or capillary electrophoresis, which require qualified staff, sample preparation and are time-c...

  10. Fluorescent lamp and ballast options

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This paper reviews some of the current technologies for fluorescent lamps and ballasts with particular focus on the most common configuration in Canada - the F32T8, 4 ft length, two-lamp ballast combination. Fluorescent lamps require a high voltage surge for start-up. Technical specifications for the F32T8 lamp were provided along with reasons why they are the preferred choice. The three types of ballasts include electromagnetic, electronic and hybrid. While electromagnetic ballasts perform the same start-up duty, they are not as efficient as electronic or hybrid ballasts. Hybrid ballasts are energy efficient, but they have problems with lamp flicker, tar leakage and shorter life expectancy. Electronic ballasts eliminate flicker, do not leak and have a life expectancy of 25 years. Electronic ballasts can be instant, rapid start, or dimmable. Energy information on different types of ballast systems was presented along with a comparison of the type of light produced according to lamp and ballast combinations. This paper also presents a case study in which the lighting system of a 25-storey building was retrofitted with energy efficient fluorescent lamps and ballasts for an energy savings of about $100,000 per year and a 5 year payback period. 2 tabs., 4 figs.

  11. Fluorescent multiple chemical sensing using time-domain fluorescence lifetime imaging

    OpenAIRE

    Nagl, Stefan

    2008-01-01

    This thesis describes applications of fluorescence lifetime imaging in multiple chemical sensing approaches. Using fluorescence lifetime as an analytical parameter allows extracting more information out of probes than fluorescence intensity measurements and it is therefore attractive in order to quantitate multiple species. It leads to better data quality as fluorescence lifetime measurements are not or less affected by many sources of noise in fluorescence signals such as straylight and othe...

  12. Fluorescence lifetime imaging of skin cancer

    Science.gov (United States)

    Patalay, Rakesh; Talbot, Clifford; Munro, Ian; Breunig, Hans Georg; König, Karsten; Alexandrov, Yuri; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Chris

    2011-03-01

    Fluorescence intensity imaging and fluorescence lifetime imaging microscopy (FLIM) using two photon microscopy (TPM) have been used to study tissue autofluorescence in ex vivo skin cancer samples. A commercially available system (DermaInspect®) was modified to collect fluorescence intensity and lifetimes in two spectral channels using time correlated single photon counting and depth-resolved steady state measurements of the fluorescence emission spectrum. Uniquely, image segmentation has been used to allow fluorescence lifetimes to be calculated for each cell. An analysis of lifetime values obtained from a range of pigmented and non-pigmented lesions will be presented.

  13. Application of Fluorescent Label in Polymer Nanofibers

    Directory of Open Access Journals (Sweden)

    Lucie Zarybnicka

    2017-01-01

    Full Text Available The electrospinning of fluorescent probe polyamide 6 doped by 7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-on is presented as a model processing photoluminescent nanofibers. The presence of the fluorescent probe in the fiber layers was confirmed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR; the surface nanofiber structure was described by high-resolution fluorescence microscope and scanning electron microscope images. The prepared nanofibers with the fluorescent label were further characterized by fluorescence spectroscopy, both in the solid phase and in the solution.

  14. Fluorescence spectroscopy of synthetic melanin in solution

    Energy Technology Data Exchange (ETDEWEB)

    Perna, G.; Frassanito, M.C. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Palazzo, G. [Dipartimento di Chimica, Universita di Bari, Via Orabona 4, 70126 Bari (Italy); Gallone, A. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Mallardi, A. [ICPS-CNR, Via Orabona 4, 70126 Bari (Italy); Biagi, P.F. [Dipartimento Interateneo di Fisica, Universita di Bari, Via Amendola 173, 70126 Bari (Italy); Capozzi, V. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy)], E-mail: v.capozzi@unifg.it

    2009-01-15

    We report a detailed investigation of fluorescence properties of synthetic eumelanin pigment in solution. A complete set of fluorescence spectra in the near-UV and visible range is analysed. Excitation spectra at a few selected emission energies are also investigated. Our measurements support the hypothesis that fluorescence in eumelanin is related to chemically distinct oligomeric units that can be selectively excited. Fluorescence due to large oligomer systems is spectrally differentiated from that due to monomers and small oligomer systems. Fluorescence excitation measurements show the contribution of 5,6-dihydroxyndole-2-carboxylic acid and 5,6-dihydroxyndole monomers to the emission of small-size oligomers.

  15. Interaction of fluorescent phospholipids with cyclodextrins.

    Science.gov (United States)

    Denz, Manuela; Haralampiev, Ivan; Schiller, Sabine; Szente, Lajos; Herrmann, Andreas; Huster, Daniel; Müller, Peter

    2016-01-01

    Fluorescent analogs of phospholipids are often employed to investigate the structure and dynamics of lipids in membranes. Some of those studies have used cyclodextrins e.g., to modulate the lipid phase. However, the role of the fluorescence moiety of analogs for the interaction between cyclodextrins and fluorescent lipids has not been investigated so far in detail. Therefore, in the present study the interaction of various fluorescent phospholipid analogs with methylated α-, β- and γ- cyclodextrins was investigated. The analogs differed in their structure, in the length of the fatty acyl chain, in the position of the fluorescence group, and in the attached fluorescence moiety (7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) or dipyrrometheneboron difluoride (BODIPY)). In aqueous buffer, cyclodextrins bind fluorescent lipids disturbing the organization of the analogs. When incorporated into lipid vesicles, analogs are selectively extracted from the membrane upon addition of cyclodextrins. The results show that the interaction of cyclodextrins with fluorescent phospholipids depends on the cyclodextrin species, the fluorescence moiety and the phospholipid structure. The presented data should be of interest for studies using fluorescent phospholipids and cyclodextrins, since the interaction between the fluorescence group and the cyclodextrin may interfere with the process(es) under study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Blue space geographies: Enabling health in place.

    Science.gov (United States)

    Foley, Ronan; Kistemann, Thomas

    2015-09-01

    Drawing from research on therapeutic landscapes and relationships between environment, health and wellbeing, we propose the idea of 'healthy blue space' as an important new development Complementing research on healthy green space, blue space is defined as; 'health-enabling places and spaces, where water is at the centre of a range of environments with identifiable potential for the promotion of human wellbeing'. Using theoretical ideas from emotional and relational geographies and critical understandings of salutogenesis, the value of blue space to health and wellbeing is recognised and evaluated. Six individual papers from five different countries consider how health can be enabled in mixed blue space settings. Four sub-themes; embodiment, inter-subjectivity, activity and meaning, document multiple experiences within a range of healthy blue spaces. Finally, we suggest a considerable research agenda - theoretical, methodological and applied - for future work within different forms of blue space. All are suggested as having public health policy relevance in social and public space. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. MENTOR: an enabler for interoperable intelligent systems

    Science.gov (United States)

    Sarraipa, João; Jardim-Goncalves, Ricardo; Steiger-Garcao, Adolfo

    2010-07-01

    A community with knowledge organisation based on ontologies will enable an increase in the computational intelligence of its information systems. However, due to the worldwide diversity of communities, a high number of knowledge representation elements, which are not semantically coincident, have appeared representing the same segment of reality, becoming a barrier to business communications. Even if a domain community uses the same kind of technologies in its information systems, such as ontologies, it doesn't solve its semantics differences. In order to solve this interoperability problem, a solution is to use a reference ontology as an intermediary in the communications between the community enterprises and the outside, while allowing the enterprises to keep their own ontology and semantics unchanged internally. This work proposes MENTOR, a methodology to support the development of a common reference ontology for a group of organisations sharing the same business domain. This methodology is based on the mediator ontology (MO) concept, which assists the semantic transformations among each enterprise's ontology and the referential one. The MO enables each organisation to keep its own terminology, glossary and ontological structures, while providing seamless communication and interaction with the others.

  18. Basic investigation of concentrator using fluorescent substance

    Energy Technology Data Exchange (ETDEWEB)

    Hayashibara, Mitsuo

    1986-12-01

    A concentrator was manufactured on an experimental basis to improve the performance of the concentrator using fluorescent substance and the analysis based on the test result of optical characteristics of the materials composing the concentrator was made. The concentrator is composed of fluorescent substance sandwiched between two acrylic sheets. Organic fluorescent solution prepared by dissolving eosin to alcohol and capsulating with transparent encapsulant was used as the fluorescent substance. The concentration ratio based on the characteristic tests of the fluorescent substance and material of acrylic sheet composing the concentrator and the numerical calculation model was calculated. The results show that the difference between the experimental and calculated values is 10%. The result of calculation based on the numerical model indicates that the energy efficiency is decreased through the concentration ratio is increased in a thin concentrator, because the fluorescence is decreased by the absorption during passing more frequently through the fluorescent layer. (1 ref, 10 figs)

  19. MiniFluo fluorescence sensor, advances in FDOM Ocean Measurements

    Science.gov (United States)

    Cyr, Frédéric; Tedetti, Marc; Goutx, Madeleine

    2017-04-01

    As part of the European project "Next generation Low-Cost Multifunctional Web Enabled Ocean Sensor Systems Empowering Marine, Maritime and Fisheries Management (NeXOS)", we developed the MiniFluo, a glider-compatible optical sensor for measurements of fluorescent dissolved organic matter (FDOM). In situ applications of the MiniFluo are presented here. The configuration used targets both natural (Tryptophan) and an anthropogenic (Phenanthrene) DOM fluorophores. Observations from three glider campaigns in the NW Mediterranean (Fall 2015 and Spring and Summer 2016) are presented. It is shown that the use of the Minifluo highlights new features of DOM dynamics in the region. For example, the Tryptophan (an amino-acid traditionally used as a tracer for waste waters) is found here closely related to open sea Chl-a fluorescence. Differences between Chl-a and Tryptophan fluorescence also give subtle information on seasonal changes in ecosystem structure and DOM release that could not be observed with traditional glider measurements. The study also highlights the presence of phenanthrene (an anthropogenic polycyclic aromatic hydrocarbon (PAH) in the surface and sub-surface waters of the Mediterranean. Implications of these finding will be put in the context of both the Mediterranean Sea DOM dynamics and also the ocean carbon cycle, from which the Dissolved Organic Carbon pool remains qualitatively unknown.

  20. Fluorescent nanosensors for intracellular measurements: synthesis, characterization, calibration, and measurement.

    Science.gov (United States)

    Desai, Arpan S; Chauhan, Veeren M; Johnston, Angus P R; Esler, Tim; Aylott, Jonathan W

    2013-01-01

    Measurement of intracellular acidification is important for understanding fundamental biological pathways as well as developing effective therapeutic strategies. Fluorescent pH nanosensors are an enabling technology for real-time monitoring of intracellular acidification. The physicochemical characteristics of nanosensors can be engineered to target specific cellular compartments and respond to external stimuli. Therefore, nanosensors represent a versatile approach for probing biological pathways inside cells. The fundamental components of nanosensors comprise a pH-sensitive fluorophore (signal transducer) and a pH-insensitive reference fluorophore (internal standard) immobilized in an inert non-toxic matrix. The inert matrix prevents interference of cellular components with the sensing elements as well as minimizing potentially harmful effects of some fluorophores on cell function. Fluorescent nanosensors are synthesized using standard laboratory equipment and are detectable by non-invasive widely accessible imaging techniques. The outcomes of studies employing this technology are dependent on reliable methodology for performing measurements. In particular, special consideration must be given to conditions for sensor calibration, uptake conditions and parameters for image analysis. We describe procedures for: (1) synthesis and characterization of polyacrylamide and silica based nanosensors, (2) nanosensor calibration and (3) performing measurements using fluorescence microscopy.

  1. Fluorescent nanosensors for intracellular measurements: synthesis, characterisation, calibration and measurement

    Directory of Open Access Journals (Sweden)

    Arpan Shailesh Desai

    2014-01-01

    Full Text Available Measurement of intracellular acidification is important for understanding fundamental biological pathways as well as developing effective therapeutic strategies. Fluorescent pH nanosensors are an enabling technology for real-time monitoring of intracellular acidification. The physicochemical characteristics of nanosensors can be engineered to target specific cellular compartments and respond to external stimuli. Therefore nanosensors represent a versatile approach for probing biological pathways inside cells. The fundamental components of nanosensors comprise a pH-sensitive fluorophore (signal transducer and a pH-insensitive reference fluorophore (internal standard immobilised in an inert non-toxic matrix. The inert matrix prevents interference of cellular components with the sensing elements as well as minimizing potentially harmful effects of some fluorophores on cell function. Fluorescent nanosensors are synthesised using standard laboratory equipment and are detectable by non-invasive widely accessibly imaging techniques. The outcomes of studies employing this technology are dependent on reliable methodology for performing measurements. In particular special consideration must be given to conditions for sensor calibration, uptake conditions and parameters for image analysis. We describe procedures for: 1 synthesis and characterisation of polyacrylamide and silica based nanosensors 2 nanosensor calibration and 3 performing measurements using fluorescence microscopy.

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

    Science.gov (United States)

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

    2016-01-01

    In-resin fluorescence (IRF) protocols preserve fluorescent proteins in resin-embedded cells and tissues for correlative light and electron microscopy, aiding interpretation of macromolecular function within the complex cellular landscape. Dual-contrast IRF samples can be imaged in separate fluorescence and electron microscopes, or in dual-modality integrated microscopes for high resolution correlation of fluorophore to organelle. IRF samples also offer a unique opportunity to automate correlative imaging workflows. Here we present two new locator tools for finding and following fluorescent cells in IRF blocks, enabling future automation of correlative imaging. The ultraLM is a fluorescence microscope that integrates with an ultramicrotome, which enables ‘smart collection’ of ultrathin sections containing fluorescent cells or tissues for subsequent transmission electron microscopy or array tomography. The miniLM is a fluorescence microscope that integrates with serial block face scanning electron microscopes, which enables ‘smart tracking’ of fluorescent structures during automated serial electron image acquisition from large cell and tissue volumes. PMID:28090593

  3. Chromophore photophysics and dynamics in fluorescent proteins of the GFP family

    Science.gov (United States)

    Nienhaus, Karin; Nienhaus, G. Ulrich

    2016-11-01

    Proteins of the green fluorescent protein (GFP) family are indispensable for fluorescence imaging experiments in the life sciences, particularly of living specimens. Their essential role as genetically encoded fluorescence markers has motivated many researchers over the last 20 years to further advance and optimize these proteins by using protein engineering. Amino acids can be exchanged by site-specific mutagenesis, starting with naturally occurring proteins as templates. Optical properties of the fluorescent chromophore are strongly tuned by the surrounding protein environment, and a targeted modification of chromophore-protein interactions requires a profound knowledge of the underlying photophysics and photochemistry, which has by now been well established from a large number of structural and spectroscopic experiments and molecular-mechanical and quantum-mechanical computations on many variants of fluorescent proteins. Nevertheless, such rational engineering often does not meet with success and thus is complemented by random mutagenesis and selection based on the optical properties. In this topical review, we present an overview of the key structural and spectroscopic properties of fluorescent proteins. We address protein-chromophore interactions that govern ground state optical properties as well as processes occurring in the electronically excited state. Special emphasis is placed on photoactivation of fluorescent proteins. These light-induced reactions result in large structural changes that drastically alter the fluorescence properties of the protein, which enables some of the most exciting applications, including single particle tracking, pulse chase imaging and super-resolution imaging. We also present a few examples of fluorescent protein application in live-cell imaging experiments.

  4. Fluorescent silica nanoparticles with chemically reactive surface: Controlling spatial distribution in one-step synthesis.

    Science.gov (United States)

    Vera, María L; Cánneva, Antonela; Huck-Iriart, Cristián; Requejo, Felix G; Gonzalez, Mónica C; Dell'Arciprete, María L; Calvo, Alejandra

    2017-06-15

    The encapsulation of fluorescent dyes inside silica nanoparticles is advantageous to improve their quality as probes. Inside the particle, the fluorophore is protected from the external conditions and its main emission parameters remains unchanged even in the presence of quenchers. On the other hand, the amine-functionalized nanoparticle surface enables a wide range of applications, as amino groups could be easily linked with different biomolecules for targeting purposes. This kind of nanoparticle is regularly synthesized by methods that employ templates, additional nanoparticle formation or multiple pathway process. However, a one-step synthesis will be an efficient approach in this sort of bifunctional hybrid nanoparticles. A co-condensation sol-gel synthesis of hybrid fluorescent silica nanoparticle where developed. The chemical and morphological characterization of the particles where investigated by DRIFTS, XPS, SEM and SAXS. The nanoparticle fluorescent properties were also assessed by excitation-emission matrices and time resolved experiments. We have developed a one-pot synthesis method that enables the simultaneous incorporation of functionalities, the fluorescent molecule and the amino group, by controlling co-condensation process. An exhaustive characterization allows the definition of the spatial distribution of the fluorescent probe, fluorescein isothiocyanate, inside the particle and reactive amino groups on the surface of the nanoparticle with diameter about 100nm. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. In vivo labelling of Anagallis arvensis L. cells with green fluorescent protein

    Directory of Open Access Journals (Sweden)

    Marcin Łukaszewicz

    2014-01-01

    Full Text Available A few methods only enable to follow the fate of plant cells in vivo. One of the most promising is using the Green Fluorescent Protein (GFP. In our preliminary study we set up the experimental system enabling labelling of Anagallis arvensis cells with this marker. We prepared an expression plasmid containing red-shifted gfp with optimised translation start site context, under the control of CaMV 35S transcription promoter. The construct was introduced into A. arvensis cells by particle bombardment. We developed two methods of material preparation for this transformation: in vitro cultured stem internodes with regenerating adventitious shoots (the earliest stages of regeneration; and shoot tips with temporarily exposed apices. The reflected light fluorescence microscope Olympus with the set of filters U-MNB designed for fluorescein detection enables the observation of GFP fluorescence. Both ordinary epidermal cells and stomata guard cells were transformed. Their fluorescence was observed for up to 14 days. Artefacts (autofluorescence of glandular trichomes and faint green glowing of meristematic tissue could be overcome by the optimisation of the filter set.

  6. Mesoscopic Fluorescence Molecular Tomography for Evaluating Engineered Tissues

    Science.gov (United States)

    Ozturk, Mehmet S.; Chen, Chao-Wei; Ji, Robin; Zhao, Lingling; Nguyen, Bao-Ngoc B.; Fisher, John P.; Chen, Yu; Intes, Xavier

    2015-01-01

    Optimization of regenerative medicine strategies includes the design of biomaterials, development of cell-seeding methods, and control of cell-biomaterial interactions within the engineered tissues. Among these steps, one paramount challenge is to non-destructively image the engineered tissues in their entirety to assess structure, function, and molecular expression. It is especially important to be able to enable cell phenotyping and monitor the distribution and migration of cells throughout the bulk scaffold. Advanced fluorescence microscopic techniques are commonly employed to perform such tasks; however, they are limited to superficial examination of tissue constructs. Therefore, the field of tissue engineering and regenerative medicine would greatly benefit from the development of molecular imaging techniques which are capable of non-destructive imaging of three-dimensional cellular distribution and maturation within a tissue-engineered scaffold beyond the limited depth of current microscopic techniques. In this review, we focus on an emerging depth-resolved optical mesoscopic imaging technique, termed Laminar Optical Tomography (LOT) or Mesoscopic Fluorescence Molecular Tomography (MFMT), which enables longitudinal imaging of cellular distribution in thick tissue engineering constructs at depths of a few millimeters and with relatively high resolution. The physical principle, image formation, and instrumentation of LOT/MFMT systems are introduced. Representative applications in tissue engineering include imaging the distribution of human mesenchymal stem cells (hMSCs) embedded in hydrogels, imaging of bio-printed tissues, and in vivo applications. PMID:26645079

  7. Enabling Computational Technologies for Terascale Scientific Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, S.F.

    2000-08-24

    We develop scalable algorithms and object-oriented code frameworks for terascale scientific simulations on massively parallel processors (MPPs). Our research in multigrid-based linear solvers and adaptive mesh refinement enables Laboratory programs to use MPPs to explore important physical phenomena. For example, our research aids stockpile stewardship by making practical detailed 3D simulations of radiation transport. The need to solve large linear systems arises in many applications, including radiation transport, structural dynamics, combustion, and flow in porous media. These systems result from discretizations of partial differential equations on computational meshes. Our first research objective is to develop multigrid preconditioned iterative methods for such problems and to demonstrate their scalability on MPPs. Scalability describes how total computational work grows with problem size; it measures how effectively additional resources can help solve increasingly larger problems. Many factors contribute to scalability: computer architecture, parallel implementation, and choice of algorithm. Scalable algorithms have been shown to decrease simulation times by several orders of magnitude.

  8. Metasurface-Enabled Remote Quantum Interference.

    Science.gov (United States)

    Jha, Pankaj K; Ni, Xingjie; Wu, Chihhui; Wang, Yuan; Zhang, Xiang

    2015-07-10

    An anisotropic quantum vacuum (AQV) opens novel pathways for controlling light-matter interaction in quantum optics, condensed matter physics, etc. Here, we theoretically demonstrate a strong AQV over macroscopic distances enabled by a judiciously designed array of subwavelength-scale nanoantennas-a metasurface. We harness the phase-control ability and the polarization-dependent response of the metasurface to achieve strong anisotropy in the decay rate of a quantum emitter located over distances of hundreds of wavelengths. Such an AQV induces quantum interference among radiative decay channels in an atom with orthogonal transitions. Quantum vacuum engineering with metasurfaces holds promise for exploring new paradigms of long-range light-matter interaction for atom optics, solid-state quantum optics, quantum information processing, etc.

  9. Microsystem enabled photovoltaic modules and systems

    Science.gov (United States)

    Nielson, Gregory N; Sweatt, William C; Okandan, Murat

    2015-05-12

    A microsystem enabled photovoltaic (MEPV) module including: an absorber layer; a fixed optic layer coupled to the absorber layer; a translatable optic layer; a translation stage coupled between the fixed and translatable optic layers; and a motion processor electrically coupled to the translation stage to controls motion of the translatable optic layer relative to the fixed optic layer. The absorber layer includes an array of photovoltaic (PV) elements. The fixed optic layer includes an array of quasi-collimating (QC) micro-optical elements designed and arranged to couple incident radiation from an intermediate image formed by the translatable optic layer into one of the PV elements such that it is quasi-collimated. The translatable optic layer includes an array of focusing micro-optical elements corresponding to the QC micro-optical element array. Each focusing micro-optical element is designed to produce a quasi-telecentric intermediate image from substantially collimated radiation incident within a predetermined field of view.

  10. Enabling plant synthetic biology through genome engineering.

    Science.gov (United States)

    Baltes, Nicholas J; Voytas, Daniel F

    2015-02-01

    Synthetic biology seeks to create new biological systems, including user-designed plants and plant cells. These systems can be employed for a variety of purposes, ranging from producing compounds of industrial or therapeutic value, to reducing crop losses by altering cellular responses to pathogens or climate change. To realize the full potential of plant synthetic biology, techniques are required that provide control over the genetic code - enabling targeted modifications to DNA sequences within living plant cells. Such control is now within reach owing to recent advances in the use of sequence-specific nucleases to precisely engineer genomes. We discuss here the enormous potential provided by genome engineering for plant synthetic biology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Enabling opportunistic resources for CMS Computing Operations

    Energy Technology Data Exchange (ETDEWEB)

    Hufnagel, Dick [Fermilab

    2015-11-19

    With the increased pressure on computing brought by the higher energy and luminosity from the LHC in Run 2, CMS Computing Operations expects to require the ability to utilize “opportunistic” resources — resources not owned by, or a priori configured for CMS — to meet peak demands. In addition to our dedicated resources we look to add computing resources from non CMS grids, cloud resources, and national supercomputing centers. CMS uses the HTCondor/glideinWMS job submission infrastructure for all its batch processing, so such resources will need to be transparently integrated into its glideinWMS pool. Bosco and parrot wrappers are used to enable access and bring the CMS environment into these non CMS resources. Here we describe our strategy to supplement our native capabilities with opportunistic resources and our experience so far using them.

  12. Multifaceted aspects of chunking enable robust algorithms.

    Science.gov (United States)

    Acuna, Daniel E; Wymbs, Nicholas F; Reynolds, Chelsea A; Picard, Nathalie; Turner, Robert S; Strick, Peter L; Grafton, Scott T; Kording, Konrad P

    2014-10-15

    Sequence production tasks are a standard tool to analyze motor learning, consolidation, and habituation. As sequences are learned, movements are typically grouped into subsets or chunks. For example, most Americans memorize telephone numbers in two chunks of three digits, and one chunk of four. Studies generally use response times or error rates to estimate how subjects chunk, and these estimates are often related to physiological data. Here we show that chunking is simultaneously reflected in reaction times, errors, and their correlations. This multimodal structure enables us to propose a Bayesian algorithm that better estimates chunks while avoiding overfitting. Our algorithm reveals previously unknown behavioral structure, such as an increased error correlations with training, and promises a useful tool for the characterization of many forms of sequential motor behavior. Copyright © 2014 the American Physiological Society.

  13. Bluetooth-enabled teleradiology: applications and complications.

    Science.gov (United States)

    Hura, Angela M

    2002-01-01

    Wireless personal area networks and local area networks are becoming increasingly more prevalent in the teleradiology and telemedicine industry. Although there has been much debate about the role that Bluetooth will play in the future of wireless technology, both promoters and doubters acknowledge that Bluetooth will have an impact on networking, even if only as a "niche" product. This article provides an overview of the Bluetooth standard and highlights current and future areas of inclusion for use in a teleradiology environment. The possibilities for Bluetooth in a teleradiology environment without wires are nearly boundless and an overview of current and proposed Bluetooth-enabled radiology equipment and vendors is provided. A comparison of Bluetooth and other wireless technologies is provided, including areas of similarity and potential conflict. Bluetooth and other wireless technologies can not only peacefully coexist but also complement each other and provide enhanced teleradiology services.

  14. Enabling Indoor Location-Based Services

    DEFF Research Database (Denmark)

    Radaelli, Laura

    of trajectory data that can be used to study how people actually use indoor spaces. In this dissertation, we contribute partial solutions that address challenges in indoor positioning and indoor trajectory management and analysis. The key enabler of indoor location-based services and indoor movement analysis...... is a well-functioning positioning system that can be easily deployed in most public places. Different technologies are able to provide indoor positioning with different accuracy and coverage, but it is difficult to find a technology that by itself can provide good positioning in the many different layouts...... of indoor spaces that exhibit more variability than outdoor spaces. We investigate the integration of different technologies for positioning. First, we examine the concept of an organic system, i.e., a system that is initialized and maintained by users, and we extend it in a vision of a fully organic indoor...

  15. Enabling a New Planning and Scheduling Paradigm

    Science.gov (United States)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Flight Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called "tasks models," from the scientists and technologists for the tasks that they want to be done. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, another cadre further modifies the models to be compatible with the scheduling engine. This last cadre also submits the models to the scheduling engine or builds the timeline manually to accommodate requirements that are expressed in notes. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components. (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphics methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models

  16. Enabling Radiation Tolerant Systems for Space

    Science.gov (United States)

    Kauffman, Billy; Hardage, Donna

    1999-01-01

    A hazard to all spacecraft orbiting the Earth is the existence of a harsh environment with its subsequent effects. The effects can provide damaging or even disabling effects on spacecraft and its instruments. One of the most recognized and serious of the different space environments is ionizing radiation and its effects on spacecraft and spacecraft systems. This is increasingly becoming more of an issue for all missions due to the use of lighter composite materials, smaller satellites, and smaller electronics. NASA's Space Environments and Effects (SEE) Program was established to develop new plateaus of technical capability to reduce the cost of NASA's missions and provide leading-edge exploratory and focused technology to promote continued U.S. preeminence in space. The SEE Program has an "Implementation Plan" to develop roadmaps and fund technical tasks to enable radiation systems for space.

  17. Health-Enabled Smart Sensor Fusion Technology

    Science.gov (United States)

    Wang, Ray

    2012-01-01

    A process was designed to fuse data from multiple sensors in order to make a more accurate estimation of the environment and overall health in an intelligent rocket test facility (IRTF), to provide reliable, high-confidence measurements for a variety of propulsion test articles. The object of the technology is to provide sensor fusion based on a distributed architecture. Specifically, the fusion technology is intended to succeed in providing health condition monitoring capability at the intelligent transceiver, such as RF signal strength, battery reading, computing resource monitoring, and sensor data reading. The technology also provides analytic and diagnostic intelligence at the intelligent transceiver, enhancing the IEEE 1451.x-based standard for sensor data management and distributions, as well as providing appropriate communications protocols to enable complex interactions to support timely and high-quality flow of information among the system elements.

  18. Grid Enabled Geospatial Catalogue Web Service

    Science.gov (United States)

    Chen, Ai-Jun; Di, Li-Ping; Wei, Ya-Xing; Liu, Yang; Bui, Yu-Qi; Hu, Chau-Min; Mehrotra, Piyush

    2004-01-01

    Geospatial Catalogue Web Service is a vital service for sharing and interoperating volumes of distributed heterogeneous geospatial resources, such as data, services, applications, and their replicas over the web. Based on the Grid technology and the Open Geospatial Consortium (0GC) s Catalogue Service - Web Information Model, this paper proposes a new information model for Geospatial Catalogue Web Service, named as GCWS which can securely provides Grid-based publishing, managing and querying geospatial data and services, and the transparent access to the replica data and related services under the Grid environment. This information model integrates the information model of the Grid Replica Location Service (RLS)/Monitoring & Discovery Service (MDS) with the information model of OGC Catalogue Service (CSW), and refers to the geospatial data metadata standards from IS0 19115, FGDC and NASA EOS Core System and service metadata standards from IS0 191 19 to extend itself for expressing geospatial resources. Using GCWS, any valid geospatial user, who belongs to an authorized Virtual Organization (VO), can securely publish and manage geospatial resources, especially query on-demand data in the virtual community and get back it through the data-related services which provide functions such as subsetting, reformatting, reprojection etc. This work facilitates the geospatial resources sharing and interoperating under the Grid environment, and implements geospatial resources Grid enabled and Grid technologies geospatial enabled. It 2!so makes researcher to focus on science, 2nd not cn issues with computing ability, data locztic, processir,g and management. GCWS also is a key component for workflow-based virtual geospatial data producing.

  19. Intelligent, net or wireless enabled fluorosensors for high throughput monitoring of assorted crops

    Science.gov (United States)

    Barócsi, Attila

    2013-02-01

    Phenotypic characterization of assorted crops of different genotypes requires large data sets of diverse types for statistical reliability. Temporal monitoring of plant fluorescence is able to capture the dynamics of the photosynthesis process that is summarized in a number of parameters for which the genotypic heritability can be calculated. In this paper, an intelligent sensor system is presented that is capable of high-throughput production of baseline-corrected temporal fluorescence curves with many feature points. These are obtained by integrating several (direct and modulated) measurement methods applied at different wavelengths. Simultaneously, temporal change of the sample's emission and the ambient reference temperatures are recorded. Multiple sensors can be deployed easily in large span greenhouse environments with centralized data collection over wired or wireless infrastructure. The unique features of the sensors are a compact, embedded signal guiding fibre optic system, instrument-standard variable tubular detector and source modules, net or wireless enabling for remote control and fast, quasi real-time data collection. Along with the instrumentation, some representative phenotyping data are also presented that were taken on a subset of pepper recombinant inbred line population. It is also demonstrated that transient fluorescence feature points yield high heritability, offering a high confidence level for distinguishing the pepper genotypes.

  20. Far-Field Fluorescence Nanoscopy

    Science.gov (United States)

    Hell, Stefan

    2009-03-01

    The resolution of a far-field optical microscopy is usually limited to d=λ/ λ( 2,α ) . - ( 2,α ) > 200 nm, with nα denoting the numerical aperture of the lens and λ the wavelength of light. While the diffraction barrier has prompted the invention of electron, scanning probe, and x-ray microscopy, the 3D-imaging of the interior of (live) cells requires the use of focused visible light. I will discuss new developments of optical microscopy that I anticipate to have a lasting impact on our understanding of living matter. Emphasis will be placed on physical concepts that have overcome the diffraction barrier in far-field fluorescence microscopy. To set the scene for future directions, I will show that all these concepts share a common strategy: exploiting selected states and transitions of the fluorescent marker to neutralize the limiting role of diffraction. The first viable concept of this kind was Stimulated Emission Depletion (STED) microscopy where the spot diameter followsd λ/ λ( 2,α√1+I / I Is . - Is ) . - ( 2,α√1+I / I Is . - Is ); I / I Is . - Isis a measure of the strength with which the molecule is send from the fluorescent state to the dark ground state. For I / I Is . - Is->∞ it follows that d->0, meaning that the resolution that can, in principle, be molecular. The concept underlying STED microscopy can be expanded by employing other transitions that shuffle the molecule between a dark and a bright state, such as (i) shelving the fluorophore in a dark triplet state, and (ii) photoswitching between a `fluorescence activated' and a `fluorescence deactivated' conformational state. Examples for the latter include photochromic organic compounds, and fluorescent proteins which undergo a cis-trans photoisomerizations. Photoswitching provides ultrahigh resolution at ultralow light levels. Switching can be performed in an ensemble or individually in which case the image is assembled molecule by molecule at high resolution. By providing molecular

  1. Red and Green Fluorescence from Oral Biofilms.

    Directory of Open Access Journals (Sweden)

    Catherine M C Volgenant

    Full Text Available Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis. Little is known about green fluorescence from biofilms. Therefore, we assessed the dynamics of red and green fluorescence in real-time during biofilm formation. In addition, the fluorescence patterns of biofilm formed from saliva of eight different donors are described under simulated gingivitis and caries conditions. Biofilm formation was analysed for 12 hours under flow conditions in a microfluidic BioFlux flow system with high performance microscopy using a camera to allow live cell imaging. For fluorescence images dedicated excitation and emission filters were used. Both green and red fluorescence were linearly related with the total biomass of the biofilms. All biofilms displayed to some extent green and red fluorescence, with higher red and green fluorescence intensities from biofilms grown in the presence of serum (gingivitis simulation as compared to the sucrose grown biofilms (cariogenic simulation. Remarkably, cocci with long chain lengths, presumably streptococci, were observed in the biofilms. Green and red fluorescence were not found homogeneously distributed within the biofilms: highly fluorescent spots (both green and red were visible throughout the biomass. An increase in red fluorescence from the in vitro biofilms appeared to be related to the clinical inflammatory response of the respective saliva donors, which was previously assessed during an in vivo period of performing no-oral hygiene. The BioFlux model proved to be a reliable model to assess biofilm fluorescence. With this model, a prediction can be made whether a patient will be prone to the development of gingivitis or caries.

  2. Red and Green Fluorescence from Oral Biofilms.

    Science.gov (United States)

    Volgenant, Catherine M C; Hoogenkamp, Michel A; Krom, Bastiaan P; Janus, Marleen M; Ten Cate, Jacob M; de Soet, Johannes J; Crielaard, Wim; van der Veen, Monique H

    2016-01-01

    Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis. Little is known about green fluorescence from biofilms. Therefore, we assessed the dynamics of red and green fluorescence in real-time during biofilm formation. In addition, the fluorescence patterns of biofilm formed from saliva of eight different donors are described under simulated gingivitis and caries conditions. Biofilm formation was analysed for 12 hours under flow conditions in a microfluidic BioFlux flow system with high performance microscopy using a camera to allow live cell imaging. For fluorescence images dedicated excitation and emission filters were used. Both green and red fluorescence were linearly related with the total biomass of the biofilms. All biofilms displayed to some extent green and red fluorescence, with higher red and green fluorescence intensities from biofilms grown in the presence of serum (gingivitis simulation) as compared to the sucrose grown biofilms (cariogenic simulation). Remarkably, cocci with long chain lengths, presumably streptococci, were observed in the biofilms. Green and red fluorescence were not found homogeneously distributed within the biofilms: highly fluorescent spots (both green and red) were visible throughout the biomass. An increase in red fluorescence from the in vitro biofilms appeared to be related to the clinical inflammatory response of the respective saliva donors, which was previously assessed during an in vivo period of performing no-oral hygiene. The BioFlux model proved to be a reliable model to assess biofilm fluorescence. With this model, a prediction can be made whether a patient will be prone to the development of gingivitis or caries.

  3. Array Based Sensing of Normal, Cancerous and Metastatic Cells using Conjugated Fluorescent Polymers

    Science.gov (United States)

    Bajaj, Avinash; Miranda, Oscar R.; Phillips, Ronnie; Kim, Ik-Bum; Jerry, D. Joseph; Bunz, Uwe H. F.; Rotello, Vincent M.

    2010-01-01

    A family of conjugated fluorescent polymers was used to create an array for cell sensing. Fluorescent conjugated polymers with pendant charged residues provided multivalent interactions with cell membranes, allowing the detection of subtle differences between different cell types on the basis of cell surface characteristics. Highly reproducible characteristic patterns were obtained from different cell types as well as from isogenic cell lines, enabling the identification of cell type as well differentiating between normal, cancerous and metastatic isogenic cell types with high accuracy. PMID:20039629

  4. Bis-pyrene-modified unlocked nucleic acids: synthesis, hybridization studies, and fluorescent properties

    DEFF Research Database (Denmark)

    Perlíková, Pavla; Ejlersen, Maria; Langkjaer, Niels

    2014-01-01

    Efficient synthesis of a building block for the incorporation of a bis-pyrene-modified unlocked nucleic acid (UNA) into oligonucleotides (DNA*) was developed. The presence of bis-pyrene-modified UNA within a duplex leads to duplex destabilization that is more profound in DNA*/RNA and less distinc......)uracil:pyrene exciplex emission in the single-stranded form. Such fluorescent properties enable the application of bis-pyrene-modified UNA in the development of fluorescence probes for DNA/RNA detection and for detection of deletions at specific positions....

  5. New approach to breast tumor detection based on fluorescence x-ray analysis

    Directory of Open Access Journals (Sweden)

    Okuyama, Fumio

    2010-01-01

    Full Text Available A new technical approach to breast-tumor detection is proposed. The technique is based on fluorescence x-ray analysis, and can identify a miniature malignant tumor within the breast. The primary beam intensity needed in fluorescence x-ray analysis is on a lower order of magnitude than that used in mammography. Thus, the newly-proposed technique would enable detection of a still tiny breast cancer while dramatically lowering the radiation dose. Field-emission x-ray sources might be a key for translating this concept into a medical technique.

  6. Imaging Lysosomal pH Alteration in Stressed Cells with a Sensitive Ratiometric Fluorescence Sensor.

    Science.gov (United States)

    Xue, Zhongwei; Zhao, Hu; Liu, Jian; Han, Jiahuai; Han, Shoufa

    2017-03-24

    The organelle-specific pH is crucial for cell homeostasis. Aberrant pH of lysosomes has been manifested in myriad diseases. To probe lysosome responses to cell stress, we herein report the detection of lysosomal pH changes with a dual colored probe (CM-ROX), featuring a coumarin domain with "always-on" blue fluorescence and a rhodamine-lactam domain activatable to lysosomal acidity to give red fluorescence. With sensitive ratiometric signals upon subtle pH changes, CM-ROX enables discernment of lysosomal pH changes in cells undergoing autophagy, cell death, and viral infection.

  7. Green fluorescent protein-like proteins in reef Anthozoa animals.

    Science.gov (United States)

    Miyawaki, Atsushi

    2002-10-01

    Green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has become an important tool in molecular and cellular biology as a transcriptional reporter, fusion tag, and biosensor. Most significantly, it encodes a chromophore intrinsically within its protein sequence, obviating the need for external substrates or cofactors and enabling the genetic encoding of strong fluorescence. Mutagenesis studies have generated GFP variants with new colors, improved fluorescence and other biochemical properties. In parallel, GFPs and GFP-like molecules have been cloned from other organisms, including the bioluminescent sea pansy Renilla reniformis and other non-bioluminescent Anthozoa animals. In the jellyfish and sea pansy, the GFPs are coupled to their chemoluminescence. Instead of emitting the blue light generated by aequorin and luciferase, the GFPs absorb their energy of primary emission and emit green light, which travels farther in the sea. In contrast, GFP-like proteins in reef Anthozoa are thought to play a role in photoprotection of their symbiotic zooxanthellae in shallow water; they transform absorbed UV radiation contained in sunlight into longer fluorescence wavelengths (Salih, A., Larkum, A., Cox, G., Kuhl, M., and Hoegh-Guldberg, O. 2000. Nature, 408: 850-853). In this review, I will describe both the biological and practical aspects of Anthozoan GFP-like proteins, many of which will be greatly improved in utility and commercially available before long. The ubiquity of these molecular tools makes it important to appreciate the interplay between sunlight and GFP-like proteins of Anthozoan animals, and to consider the optimal use of these unique proteins in biological studies.

  8. Graphitic Nitrogen Triggers Red Fluorescence in Carbon Dots.

    Science.gov (United States)

    Holá, Kateřina; Sudolská, Mária; Kalytchuk, Sergii; Nachtigallová, Dana; Rogach, Andrey L; Otyepka, Michal; Zbořil, Radek

    2017-11-20

    Carbon dots (CDs) are a stable and highly biocompatible fluorescent material offering great application potential in cell labeling, optical imaging, LED diodes, and optoelectronic technologies. Because their emission wavelengths provide the best tissue penetration, red-emitting CDs are of particular interest for applications in biomedical technologies. Current synthetic strategies enabling red-shifted emission include increasing the CD particle size (sp2 domain) by a proper synthetic strategy and tuning the surface chemistry of CDs with suitable functional groups (e.g., carboxyl). Here we present an elegant route for preparing full-color CDs with well-controllable fluorescence at blue, green, yellow, or red wavelengths. The two-step procedure involves the synthesis of a full-color-emitting mixture of CDs from citric acid and urea in formamide followed by separation of the individual fluorescent fractions by column chromatography based on differences in CD charge. Red-emitting CDs, which had the most negative charge, were separated as the last fraction. The trend in the separation, surface charge, and red-shift of photoluminescence was caused by increasing amount of graphitic nitrogen in the CD structure, as was clearly proved by XPS, FT-IR, Raman spectroscopy, and DFT calculations. Importantly, graphitic nitrogen generates midgap states within the HOMO-LUMO gap of the undoped systems, resulting in significantly red-shifted light absorption that in turn gives rise to fluorescence at the low-energy end of the visible spectrum. The presented findings identify graphitic nitrogen as another crucial factor that can red-shift the CD photoluminescence.

  9. Contribution of chlorophyll fluorescence to the apparent vegetation reflectance

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, P.K. Entcheva [Joint Center for Earth Systems Technology, UMBC, Baltimore, MD 21228 (United States); Biospheric Sciences Branch, Hydrospheric and Biospheric Sciences Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)], E-mail: pcampbel@pop900.gsfc.nasa.gov; Middleton, E.M. [Biospheric Sciences Branch, Hydrospheric and Biospheric Sciences Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States); Corp, L.A. [Biospheric Sciences Branch, Hydrospheric and Biospheric Sciences Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States); Agricultural Research Service, USDA, Beltsville, MD 20705 (United States); Kim, M.S. [Agricultural Research Service, USDA, Beltsville, MD 20705 (United States)

    2008-10-15

    emitting much higher fluorescence amounts, as compared to corn and soybean. Steady state fluorescence from individual red and far-red emission bands (F685 and F740, respectively) and their ratio consistently enabled species separation. For corn, the relative ChlF fraction increased in concert with the nutrient stress levels from < 2% for non-stressed foliage to > 7% for severely N deficient plants. Steady state ChlF at 685 nm provided optimal N treatment separation. This study confirms the trends in the steady state red/far-red ratio (F685s/F740s) associated with N deficiency and vegetation stress, previously established using active single narrow band excitation.

  10. Firearm Projectile in the Maxillary Tuberosity Located by Adjunctive Examination of Wide-Field Optical Fluorescence.

    Science.gov (United States)

    Andrade, Sérgio Araújo; Varotti, Fernando de Pilla; Bagnato, Vanderlei Salvador; Pratavieira, Sebastião

    2017-10-10

    Demonstrate the use of wide-field optical fluorescence as an adjunctive examination in a clinical routine to oral diagnosis. Use of wide-field optical fluorescence in the oral cavity has been restricted to topics related to the detection and diagnosis of oral cancer. In a regular medical appointment, a 58-year-old female patient, without any complaint or oral symptom, underwent the complementary examination by wide-field optical fluorescence. A device with high-power light-emitting diode emitting light centered at a wavelength of (400 ± 10) nm and maximum irradiance of (0.040 ± 0.008) W/cm(2) was used for fluorescence visualization. We report the location of a firearm projectile, intraosseous, in the maxillary tuberosity using wide-field optical fluorescence. It is evidenced that wide-field optical fluorescence, within a clinical routine, can provide relevant images and data, with an immediate result, without the use of ionizing radiation, enabling an efficient oral diagnosis.

  11. Online multispectral fluorescence lifetime values estimation and overlay onto tissue white-light video frames

    Science.gov (United States)

    Gorpas, Dimitris; Ma, Dinglong; Bec, Julien; Yankelevich, Diego R.; Marcu, Laura

    2016-03-01

    Fluorescence lifetime imaging has been shown to be a robust technique for biochemical and functional characterization of tissues and to present great potential for intraoperative tissue diagnosis and guidance of surgical procedures. We report a technique for real-time mapping of fluorescence parameters (i.e. lifetime values) onto the location from where the fluorescence measurements were taken. This is achieved by merging a 450 nm aiming beam generated by a diode laser with the excitation light in a single delivery/collection fiber and by continuously imaging the region of interest with a color CMOS camera. The interrogated locations are then extracted from the acquired frames via color-based segmentation of the aiming beam. Assuming a Gaussian profile of the imaged aiming beam, the segmentation results are fitted to ellipses that are dynamically scaled at the full width of three automatically estimated thresholds (50%, 75%, 90%) of the Gaussian distribution's maximum value. This enables the dynamic augmentation of the white-light video frames with the corresponding fluorescence decay parameters. A fluorescence phantom and fresh tissue samples were used to evaluate this method with motorized and hand-held scanning measurements. At 640x512 pixels resolution the area of interest augmented with fluorescence decay parameters can be imaged at an average 34 frames per second. The developed method has the potential to become a valuable tool for real-time display of optical spectroscopy data during continuous scanning applications that subsequently can be used for tissue characterization and diagnosis.

  12. Discrimination of trace nitroaromatics using linear discriminant analysis on aerosol jet printed fluorescent sensor arrays

    Science.gov (United States)

    Bolse, N.; Eckstein, R.; Schend, M.; Habermehl, A.; Hernandez-Sosa, G.; Eschenbaum, C.; Lemmer, U.

    2017-05-01

    In this work, we report on fluorescent sensor arrays fabricated by aerosol jet printing on glass substrates to detect explosives-related nitroaromatic species. The printed sensor arrays consist of six different fluorescent polymers responding to nitroaromatic vapors through a photo-induced electron transfer. This results in a quenched fluorescence proportional to the vapor concentration. Distinct fluorescence quenching patterns are detected for nitroaromatic species including nitrobenzene, 1,3-dinitrobenzene and 2,4-dinitrotoluene. The detected fingerprints are evaluated at low concentrations of only 1, 3 and 10 parts-per-billion in air. Linear discriminant analysis is used to train each sensor array enabling the discrimination of the target analyte vapors. To investigate the reproducibility of multiple sensor arrays on a single substrate, the measured fluorescence quenching patterns are used to benchmark the linear discriminant models. For this purpose, the target analytes and vapor concentrations are predicted for each sensor array. On average, we report low and reproducible misclassification rates of about 4 % indicating excellent discriminatory abilities at low concentrations close to the detection limits. We conclude that digital printing of fluorescent polymers offers the potential to realize low-cost sensor arrays for a reliable detection of trace explosives.

  13. Chromosome characterization using single fluorescent dye

    Energy Technology Data Exchange (ETDEWEB)

    Crissman, Harry A. (Los Alamos, NM); Hirons, Gregory T. (Irvine, CA)

    1995-01-01

    Chromosomes are characterized by fluorescent emissions from a single fluorescent dye that is excited over two different wavelengths. A mixture containing chromosomes is stained with a single dye selected from the group consisting of TOTO and YOYO and the stained chromosomes are placed in a flow cytometer. The fluorescent dye is excited sequentially by a first light having a wavelength in the ultraviolet range to excite the TOTO or YOYO to fluoresce at a first intensity and by a second light having a wavelength effective to excite the TOTO or YOYO dye to fluoresce at a second intensity. Specific chromosomes may be identified and sorted by intensity relationships between the first and second fluorescence emissions.

  14. Detection of Counterfeit Tequila by Fluorescence Spectroscopy

    Directory of Open Access Journals (Sweden)

    José Manuel de la Rosa Vázquez

    2015-01-01

    Full Text Available An ultraviolet (UV light induced fluorescence study to discriminate fake tequila from genuine ones is presented. A portable homemade system based on four light emitting diodes (LEDs from 255 to 405 nm and a miniature spectrometer was used. It has been shown that unlike fake and silver tequila, which produce weak fluorescence signal, genuine mixed, rested, and aged tequilas show high fluorescence emission in the range from 400 to 750 nm. The fluorescence intensity grows with aging in 100% agave tequila. Such fluorescence differences can even be observed with naked eyes. The presented results demonstrate that the fluorescence measurement could be a good method to detect counterfeit tequila.

  15. Enabling Wireless Avionics Intra-Communications

    Science.gov (United States)

    Torres, Omar; Nguyen, Truong; Mackenzie, Anne

    2016-01-01

    The Electromagnetics and Sensors Branch of NASA Langley Research Center (LaRC) is investigating the potential of an all-wireless aircraft as part of the ECON (Efficient Reconfigurable Cockpit Design and Fleet Operations using Software Intensive, Networked and Wireless Enabled Architecture) seedling proposal, which is funded by the Convergent Aeronautics Solutions (CAS) project, Transformative Aeronautics Concepts (TAC) program, and NASA Aeronautics Research Institute (NARI). The project consists of a brief effort carried out by a small team in the Electromagnetic Environment Effects (E3) laboratory with the intention of exposing some of the challenges faced by a wireless communication system inside the reflective cavity of an aircraft and to explore potential solutions that take advantage of that environment for constructive gain. The research effort was named EWAIC for "Enabling Wireless Aircraft Intra-communications." The E3 laboratory is a research facility that includes three electromagnetic reverberation chambers and equipment that allow testing and generation of test data for the investigation of wireless systems in reflective environments. Using these chambers, the EWAIC team developed a set of tests and setups that allow the intentional variation of intensity of a multipath field to reproduce the environment of the various bays and cabins of large transport aircraft. This setup, in essence, simulates an aircraft environment that allows the investigation and testing of wireless communication protocols that can effectively be used as a tool to mitigate some of the risks inherent to an aircraft wireless system for critical functions. In addition, the EWAIC team initiated the development of a computational modeling tool to illustrate the propagation of EM waves inside the reflective cabins and bays of aircraft and to obtain quantifiable information regarding the degradation of signals in aircraft subassemblies. The nose landing gear of a UAV CAD model was used

  16. Halochromic Isoquinoline with Mechanochromic Triphenylamine: Smart Fluorescent Material for Rewritable and Self-Erasable Fluorescent Platform.

    Science.gov (United States)

    Hariharan, Palamarneri Sivaraman; Mothi, Ebrahim M; Moon, Dohyun; Anthony, Savarimuthu Philip

    2016-12-07

    Halochromic isoquinoline attached mechanochromic triphenylamine, N-phenyl-N-(4-(quinolin-2-yl)phenyl)benzenamine (PQPBA) and tris(4-(quinolin-2-yl)phenyl)amine (TQPA), smart fluorescent materials exhibit thermo/mechanochromism and tunable solid state fluorescence and their unusual halochromic response in PMMA matrix have been used for fabricating rewritable and self-erasable fluorescent platforms. PQPBA and TQPA showed strong fluorescence in solution (Φf = 0.9290 (PQPBA) and 0.9160 (TQPA)) and moderate solid state fluorescence (Φf = 20 (PQPBA) and 17% (TQPA). Interestingly, they exhibited a rare temperature (0-100 °C) dependent positive fluorescence enhancement via activating radiative vibrational transition. The deaggregation of PQPBA and TQPA in PMMA polymer matrix lead to the enhancement of fluorescence intensity strongly and fabricated strong blue fluorescent thin films (Φf = 58% (PQPBA) and 54% (TQPA). The halochromic isoquinoline has been exploited for demonstrating reversible off-on fluorescence switching by acid (TFA (trifluoroacetic acid)/HCl) and base (NH3) treatment in both solids as well as PMMA thin films. Importantly, rewritable and self-erasable fluorescent platform has been achieved by make use of unusual fluorescence responses of PQPBA/TQPA with TFA/HCl after exposing NH3. Single crystal and powder X-ray diffraction (PXRD) studies provided the insight on the solid-state fluorescence and external stimuli-induced fluorescence changes.

  17. Enabling the enabler: Using access to information to ensure the right ...

    African Journals Online (AJOL)

    ... the protestinfo.org.za website. The results of these efforts show that compliance with the RGA is uneven. This article explores the flaws in the regulatory environment that have led to this level of apathy within government, despite the crucial role of the right to protest and the right of access to information as enabling rights in ...

  18. Willing and Enabled: The Academic Outcomes of a Tertiary Enabling Program in Regional Australia

    Science.gov (United States)

    Andrewartha, Lisa; Harvey, Andrew

    2014-01-01

    This paper examines the achievement levels of students undertaking the Tertiary Enabling Program (TEP) at La Trobe University. The TEP is an alternative pathway program that traverses multiple institutions, campuses, and disciplinary areas, and is designed to prepare a diverse student cohort for tertiary study. The Program integrates several…

  19. Vision and operational concept for enabling advanced traveler information services : market readiness assessment (EnableATIS).

    Science.gov (United States)

    2012-05-01

    The purpose of this market readiness assessment is to identify next steps for USDOT to research, demonstrate and advance the objectives of EnableATIS. This will include demonstrating those key concepts that will be within the USDOT and agency sphere ...

  20. Barium transport in fluorescent lamps

    Science.gov (United States)

    Sigeneger, F.; Rackow, K.; Uhrlandt, D.; Ehlbeck, J.; Lieder, G.

    2008-10-01

    The transport of barium atoms and ions in the cathode region of fluorescent lamps driven at 25,Hz is studied experimentally and theoretically. The density of Ba atoms and ions have been measured time-resolved by laserinduced fluorescence at different distances from the spot center. Furthermore, the time-dependent cathode fall voltage was approximately determined using an improved band method. The model comprises the solution of the time-dependent particle balance equations of Ba and Ba^+ which include the Ba ionization as gain and loss terms, respectively. The ionization rate coefficient of Ba and the electron density are determined by solving the space-dependent electron Boltzmann equation in spherical geometry using the measured cathode fall voltage and the discharge current as input. Good agreement between the measured and calculated density profiles of barium atoms has been obtained. The results demonstrate the sensitive dependence of the Ba density profiles on the ionization which leads to a strong depletion of the Ba density in the cathode phase of the investigated electrode. The model yields the Ba flux from the cathode which limits the lifetime of the lamp.

  1. Light Sheet Fluorescence Microscopy (LSFM).

    Science.gov (United States)

    Adams, Michael W; Loftus, Andrew F; Dunn, Sarah E; Joens, Matthew S; Fitzpatrick, James A J

    2015-01-05

    The development of confocal microscopy techniques introduced the ability to optically section fluorescent samples in the axial dimension, perpendicular to the image plane. These approaches, via the placement of a pinhole in the conjugate image plane, provided superior resolution in the axial (z) dimension resulting in nearly isotropic optical sections. However, increased axial resolution, via pinhole optics, comes at the cost of both speed and excitation efficiency. Light sheet fluorescent microscopy (LSFM), a century-old idea made possible with modern developments in both excitation and detection optics, provides sub-cellular resolution and optical sectioning capabilities without compromising speed or excitation efficiency. Over the past decade, several variations of LSFM have been implemented each with its own benefits and deficiencies. Here we discuss LSFM fundamentals and outline the basic principles of several major light-sheet-based imaging modalities (SPIM, inverted SPIM, multi-view SPIM, Bessel beam SPIM, and stimulated emission depletion SPIM) while considering their biological relevance in terms of intrusiveness, temporal resolution, and sample requirements. Copyright © 2015 John Wiley & Sons, Inc.

  2. TIR lenses for fluorescent lamps

    Science.gov (United States)

    Parkyn, William A.; Pelka, David G.

    1995-08-01

    The total internal reflection lens has been successfully applied to the efficient collimation of light from incandescent lamps and light-emitting diodes, and it is currently being marketed in several retail products. These circularly symmetric designs operated with relatively small sources. Two new forms of the TIR lens have been designed, and prototypes fabricated, for forming beams from fluorescent lamps. The toroidal fluorescent lamp is formed by circularly sweeping a faceted profile about its outer edge. A 5 inch diameter prototype lens has been diamond turned, and has 80% efficiency. When covering a 2.5 inch toroidal source of 0.25 inch minor diameter, it forms a smooth structureless beam of 40 degrees FWHM. The linear TIR lens has a faceted profile that is extended in cylindrical symmetry. In conjunction with a planar back mirror, a 6 inch diameter lens collects 85% of the light from a 5/8 inch lamp. The full width at half maximum is 30 degrees transversely and 120 degrees longitudinally, in a stripe pattern with twin peaks at +/- 47 degrees parallel to the lamp axis. These designs are applicable to other tubular light sources: discharge lamps, such as aircraft strobes and camera flashlamps, as well as neon lamps. They offer greater efficiency, narrower beamwidths, and much more compact profiles than conventional relfector designs.

  3. Super-resolution methods for fluorescence microscopy

    OpenAIRE

    Mandula, Ondrej

    2013-01-01

    Fluorescence microscopy is an important tool for biological research. However, the resolution of a standard fluorescence microscope is limited by diffraction, which makes it difficult to observe small details of a specimen’s structure. We have developed two fluorescence microscopy methods that achieve resolution beyond the classical diffraction limit. The first method represents an extension of localisation microscopy. We used nonnegative matrix factorisation (NMF) to model ...

  4. Fluorescence fluctuation spectroscopy (FFS), part A

    CERN Document Server

    Tetin, Sergey

    2013-01-01

    This new volume of Methods in Enzymology continues the legacy of this premier serial by containing quality chapters authored by leaders in the field. This volume covers Fluorescence Fluctuation SpectroscopyContains chapters on such topics as Time-integrated fluorescence cumulant analysis, Pulsed Interleaved Excitation, and raster image correlation spectroscopy and number and brightness analysis.Continues the legacy of this premier serial with quality chapters authored by leaders in the fieldCovers fluorescence fluctuation spectroscopyContains chapte

  5. Fluorescent Flippers for Mechanosensitive Membrane Probes

    OpenAIRE

    Dal Molin, Marta; Verolet, Quentin; Colom Diego, Adai; Letrun, Romain; Derivery, Emmanuel; Gonzalez Gaitan, Marcos; Vauthey, Eric; Roux, Aurélien; Sakai, Naomi; Matile, Stefan

    2015-01-01

    In this report, ?fluorescent flippers? are introduced to create planarizable push?pull probes with the mechanosensitivity and fluorescence lifetime needed for practical use in biology. Twisted push?pull scaffolds with large and bright dithienothiophenes and their S,S-dioxides as the first ?fluorescent flippers? are shown to report on the lateral organization of lipid bilayers with quantum yields above 80% and lifetimes above 4 ns. Their planarization in liquid-ordered (Lo) and solid-ordered (...

  6. Fluorescent flippers for mechanosensitive membrane probes.

    OpenAIRE

    Dal Molin Marta; Verolet Quentin; Colom Adai; Letrun Romain; Derivery Emmanuel; Gonzalez-Gaitan Marcos; Vauthey Eric; Roux Aurélien; Sakai Naomi; Matile Stefan

    2015-01-01

    In this report "fluorescent flippers" are introduced to create planarizable push pull probes with the mechanosensitivity and fluorescence lifetime needed for practical use in biology. Twisted push pull scaffolds with large and bright dithienothiophenes and their SS dioxides as the first "fluorescent flippers" are shown to report on the lateral organization of lipid bilayers with quantum yields above 80 and lifetimes above 4 ns. Their planarization in liquid ordered (Lo) and solid ordered (So)...

  7. Combined fluorescence and phosphorescence lifetime imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shcheslavskiy, V. I. [Becker & Hickl GmbH, Nahmitzer Damm 30, Berlin 12277 (Germany); Institute of Biomedical Technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod 603005 (Russian Federation); Neubauer, A.; Becker, W. [Becker & Hickl GmbH, Nahmitzer Damm 30, Berlin 12277 (Germany); Bukowiecki, R.; Dinter, F. [Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Str. 10, Berlin 13092 (Germany)

    2016-02-29

    We present a lifetime imaging technique that simultaneously records the fluorescence and phosphorescence lifetime images in confocal laser scanning systems. It is based on modulating a high-frequency pulsed laser synchronously with the pixel clock of the scanner, and recording the fluorescence and phosphorescence signals by multidimensional time-correlated single photon counting board. We demonstrate our technique on the recording of the fluorescence/phosphorescence lifetime images of human embryonic kidney cells at different environmental conditions.

  8. Enabling scientific workflows in virtual reality

    Science.gov (United States)

    Kreylos, O.; Bawden, G.; Bernardin, T.; Billen, M.I.; Cowgill, E.S.; Gold, R.D.; Hamann, B.; Jadamec, M.; Kellogg, L.H.; Staadt, O.G.; Sumner, D.Y.

    2006-01-01

    To advance research and improve the scientific return on data collection and interpretation efforts in the geosciences, we have developed methods of interactive visualization, with a special focus on immersive virtual reality (VR) environments. Earth sciences employ a strongly visual approach to the measurement and analysis of geologic data due to the spatial and temporal scales over which such data ranges, As observations and simulations increase in size and complexity, the Earth sciences are challenged to manage and interpret increasing amounts of data. Reaping the full intellectual benefits of immersive VR requires us to tailor exploratory approaches to scientific problems. These applications build on the visualization method's strengths, using both 3D perception and interaction with data and models, to take advantage of the skills and training of the geological scientists exploring their data in the VR environment. This interactive approach has enabled us to develop a suite of tools that are adaptable to a range of problems in the geosciences and beyond. Copyright ?? 2008 by the Association for Computing Machinery, Inc.

  9. Barriers and enablers to academic health leadership.

    Science.gov (United States)

    Bharwani, Aleem; Kline, Theresa; Patterson, Margaret; Craighead, Peter

    2017-02-06

    Purpose This study sought to identify the barriers and enablers to leadership enactment in academic health-care settings. Design/methodology/approach Semi-structured interviews ( n = 77) with programme stakeholders (medical school trainees, university leaders, clinical leaders, medical scientists and directors external to the medical school) were conducted, and the responses content-analysed. Findings Both contextual and individual factors were identified as playing a role in affecting academic health leadership enactment that has an impact on programme development, success and maintenance. Contextual factors included sufficient resources allocated to the programme, opportunities for learners to practise leadership skills, a competent team around the leader once that person is in place, clear expectations for the leader and a culture that fosters open communication. Contextual barriers included highly bureaucratic structures, fear-of-failure and non-trusting cultures and inappropriate performance systems. Programmes were advised to select participants based on self-awareness, strong communication skills and an innovative thinking style. Filling specific knowledge and skill gaps, particularly for those not trained in medical school, was viewed as essential. Ineffective decision-making styles and tendencies to get involved in day-to-day activities were barriers to the development of academic health leaders. Originality/value Programmes designed to develop academic health-care leaders will be most effective if they develop leadership at all levels; ensure that the organisation's culture, structure and processes reinforce positive leadership practices; and recognise the critical role of teams in supporting its leaders.

  10. Multimode Communication Protocols Enabling Reconfigurable Radios

    Directory of Open Access Journals (Sweden)

    Berlemann Lars

    2005-01-01

    Full Text Available This paper focuses on the realization and application of a generic protocol stack for reconfigurable wireless communication systems. This focus extends the field of software-defined radios which usually concentrates on the physical layer. The generic protocol stack comprises common protocol functionality and behavior which are extended through specific parts of the targeted radio access technology. This paper considers parameterizable modules of basic protocol functions residing in the data link layer of the ISO/OSI model. System-specific functionality of the protocol software is realized through adequate parameterization and composition of the generic modules. The generic protocol stack allows an efficient realization of reconfigurable protocol software and enables a completely reconfigurable wireless communication system. It is a first step from side-by-side realized, preinstalled modes in a terminal towards a dynamic reconfigurable anymode terminal. The presented modules of the generic protocol stack can also be regarded as a toolbox for the accelerated and cost-efficient development of future communication protocols.

  11. Enabling electroweak baryogenesis through dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, Marek [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Department of Physics and Michigan Center for Theoretical Physics, University of Michigan,450 Church St., Ann Arbor, MI 48109 (United States); Rindler-Daller, Tanja [Department of Physics and Michigan Center for Theoretical Physics, University of Michigan,450 Church St., Ann Arbor, MI 48109 (United States); Institut für Astrophysik, Universitätssternwarte Wien, University of Vienna,Türkenschanzstr. 17, 1180 Vienna (Austria); Wells, James D. [Department of Physics and Michigan Center for Theoretical Physics, University of Michigan,450 Church St., Ann Arbor, MI 48109 (United States)

    2016-06-09

    We study the impact on electroweak baryogenesis from a swifter cosmological expansion induced by dark matter. We detail the experimental bounds that one can place on models that realize it, and we investigate the modifications of these bounds that result from a non-standard cosmological history. The modifications can be sizeable if the expansion rate of the Universe increases by several orders of magnitude. We illustrate the impact through the example of scalar field dark matter, which can alter the cosmological history enough to enable a strong-enough first-order phase transition in the Standard Model when it is supplemented by a dimension six operator directly modifying the Higgs boson potential. We show that due to the modified cosmological history, electroweak baryogenesis can be realized, while keeping deviations of the triple Higgs coupling below HL-LHC sensitivies. The required scale of new physics to effectuate a strong-enough first order phase transition can change by as much as twenty percent as the expansion rate increases by six orders of magnitude.

  12. Smart sensors enable smart air conditioning control.

    Science.gov (United States)

    Cheng, Chin-Chi; Lee, Dasheng

    2014-06-24

    In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.

  13. Smart Sensors Enable Smart Air Conditioning Control

    Directory of Open Access Journals (Sweden)

    Chin-Chi Cheng

    2014-06-01

    Full Text Available In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants’ information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans’ intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It’s also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.

  14. Enabling technologies for autonomous MAV operations

    Science.gov (United States)

    Elbanhawi, M.; Mohamed, A.; Clothier, R.; Palmer, J. L.; Simic, M.; Watkins, S.

    2017-05-01

    The utility of micro air vehicles (MAVs) has expanded significantly in the last decade, and there are now numerous commercial systems available at relatively low cost. This expansion has arisen mainly due to the miniaturisation of flight control systems and advances in energy storage and propulsion technologies. Several emerging applications involve routine operation of MAVs in complex urban environments such as parcel delivery, communications relay and environmental monitoring. However, MAVs currently rely on one or more operators-in-the-loop and, whilst desirable, full autonomous operation has not yet been achieved. In this review paper, autonomous MAV operation in complex environments is explored with conceptualisation for future MAV operation in urban environments. Limitations of current technologies are systematically examined through consideration of the state-of-the-art and future trends. The main limitations challenging the realisation of fully autonomous MAVs are mainly attributed to: computational power, communication and energy storage. These limitations lead to poor sensing and planning capabilities, which are essential components of autonomous MAVs. Possible solutions are explored with goal of enabling MAVs to reliably operate autonomously in urban environments.

  15. Enabling Process Alignment for IT Entrepreneurship

    Directory of Open Access Journals (Sweden)

    Sonia D. Bot

    2012-11-01

    Full Text Available All firms use information technology (IT. Larger firms have IT organizations whose business function is to supply and manage IT infrastructure and applications to support the firm's business objectives. Regardless of whether the IT function has been outsourced or is resident within a firm, the objectives of the IT organization must be aligned to the strategic needs of the business. It is often a challenge to balance the demand for IT against the available supply within the firm. Most IT organizations have little capacity to carry out activities that go beyond the incremental ones that are needed to run the immediate needs of the business. A process-ambidexterity framework for IT improves the IT organization's entrepreneurial ability, which in turn, better aligns the IT function with the business functions in the firm. Process ambidexterity utilizes both process alignment and process adaptability. This article presents a framework for process alignment in IT. This is useful for understanding how the processes in Business Demand Management, a core component of the process-ambidexterity framework for IT, relate to those in IT Governance and IT Supply Chain Management. The framework is presented through three lenses (governance, business, and technology along with real-world examples from major firms in the USA. Enabling process alignment in the IT function, and process ambidexterity overall, benefits those who govern IT, the executives who lead IT, as well as their peers in the business functions that depend on IT.

  16. Enabling students to make investigations through spreadsheets

    Directory of Open Access Journals (Sweden)

    Erol - KARAKIRIK

    2015-01-01

    Full Text Available Spreadsheets are widely used in education to save time and simulate many scenarios in many different disciplines. However, they are not usually employed to provide rich interactions in the class although they provide huge computational powers and relate data in different places. It is argued in this paper that spreadsheets could also be used as an empowering tool for making inferences in the class by enabling students to investigate an open-ended problem, to make discussions about the problem and to share their results by turning a spreadsheet into an empowering tool. Constructivist approach requires students make conjectures and test them through cognitive tools provided such as Dynamic geometry environments. User could be required to investigate an open-ended problem by the help of available macros or templates provided by the instructor in a spreadsheet. It not only motivates the user to participate in the class but also make them think about the problem at hand. Our approach is exemplified through macros prepared for a math class and divisibility features of binomial coefficients were investigated through spreadsheets in this paper.

  17. Internet-enabled continuous geodetic reference station

    Science.gov (United States)

    Snow, R.; Dokka, R.

    2003-04-01

    Until recently, real-time geodesy through the Internet using geodetic GPS receivers has required either a co-located PC or a device server to convert serial data to IP. The Internet-enabled Continuous Geodetic Reference System (iCGRS) from Thales Navigation eliminates this requirement, thus saving up to 35 Watts per site. The user assigns a static IP address to the receiver and can thereafter communicate with the iCGRS through a web browser. The iCGRS supports streaming of GPS data in either BINEX or proprietary formats to up to five IP sockets, which can be either servers or clients. It can also stream RTCM corrections to these same sockets. The iCGRS can also automatically push session files to an FTP site simultaneously with the streaming of data. Sessions can be as short as 15 minutes or as long as 24 hours. Because the iCGRS significantly simplifies the communication equipment requirements for real-time geodesy, Louisiana State University has selected it for the backbone of the Louisiana Spatial Reference Center network. Fourteen iCGRS units will be installed statewide for multiple purposes, including Continuous Operating Reference Stations (CORS), subsidence monitoring and the streaming of RTCM corrections through the Internet.

  18. Nanomaterial-enabled membranes for water treatment

    Science.gov (United States)

    Rogensues, Adam Roy

    Incorporating engineered nanomaterials as components of synthetic membranes can improve their separation performance and endow membranes with additional functions. This work explores two approaches to the design of membranes modified with nanomaterials. In the first chapter, exfoliated graphite nanoplatelets (xGnP) decorated with gold nanoparticles were embedded in a polysulfone matrix to fabricate phase inversion nanocomposite membranes. The cast membranes were evaluated as flow-through membrane reactors in experiments on the catalytic reduction of 4-nitrophenol. The nanocomposite membranes were not as catalytically efficient as those fabricated by modifying anodized alumina membranes polyelectrolyte multilayers (PEMs) containing gold nanoparticles. However, because of the facility of membrane casting by phase inversion and new opportunities enabled by the demonstrated hierarchy-based approach to nanocomposite membrane design, such membrane may hold commercial promise. In the second part of the study, the practicability of PEM-based nanofiltration was evaluated under conditions of precipitative fouling (i.e. scaling) by calcium sulfate. Polyelectrolytes were deposited onto 50 kDa polyethersulfone membranes to create PEM-based nanofiltration membranes. The prepared membranes were compared with the commercial NF270 membrane in terms of flux and rejection performance, as well as the morphology of gypsum crystals formed on the membrane surface. None of the PEM coatings tested inhibited scale formation.

  19. Enabler for the agile virtual enterprise

    Science.gov (United States)

    Fuerst, Karl; Schmidt, Thomas; Wippel, Gerald

    2001-10-01

    In this presentation, a new approach for a flexible low-cost Internet extended enterprise (project FLoCI-EE) will be presented. FLoCI-EE is a project in the fifth framework program of the European commission with 8 partners from 4 countries, which started in January 2001 and will be finished in December 2003. The main objective of FLoCI-EE is the development of a software prototype, which enables flexible enterprise cooperation with the aim to design, manufacture and sell products commonly, independent of enterprise borderlines. The needed IT-support includes functions of product data management (PDM), enterprise resource planning (ERP), supply chain management (SCM) and customer relationship management (CRM). Especially for small and medium sized enterprises, existing solutions are too expensive and inflexible to be of use under current turbulent market conditions. The second part of this paper covers the item Web Services, because in the role-specific support approach of FLoCI-EE, there are user- interface-components, which are tailored for specific roles in an enterprise. These components integrate automatically the services of the so-called basic-components, and the externally offered Web Services like UDDI.

  20. Two-focus fluorescence correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dertinger, T.

    2007-05-15

    Fluorescence Correlation Spectroscopy (FCS) has been invented more than 30 years ago and experienced a renaissance after stable and affordable laser sources and low-noise single-photon detectors have become available. Its ability to measure diffusion coefficients at nanomolar concentrations of analyte made it a widely used tool in biophysics. However, in recent years it has been shown by many authors that aberrational (e.g. astigmatism) and photophysical effects (e.g. optical saturation) may influence the result of an FCS experiment dramatically, so that a precise and reliable estimation of the diffusion coefficient is no longer possible. In this thesis, we report on the development, implementation, and application of a new and robust modification of FCS that we termed two-focus FCS (2fFCS) and which fulfils two requirements: (i) It introduces an external ruler into the measurement by generating two overlapping laser foci of precisely known and fixed distance. (ii) These two foci and corresponding detection regions are generated in such a way that the corresponding molecule detection functions (MDFs) are sufficiently well described by a simple two-parameter model yielding accurate diffusion coefficients when applied to 2fFCS data analysis. Both these properties enable us to measure absolute values of the diffusion coefficient with an accuracy of a few percent. Moreover, it will turn out that the new technique is robust against refractive index mismatch, coverslide thickness deviations, and optical saturation effects, which so often trouble conventional FCS measurements. This thesis deals mainly with the introduction of the new measurement scheme, 2fFCS, but also presents several applications with far-reaching importance. (orig.)

  1. Recent Progress in Fluorescent Imaging Probes

    Science.gov (United States)

    Pak, Yen Leng; Swamy, K. M. K.; Yoon, Juyoung

    2015-01-01

    Due to the simplicity and low detection limit, especially the bioimaging ability for cells, fluorescence probes serve as unique detection methods. With the aid of molecular recognition and specific organic reactions, research on fluorescent imaging probes has blossomed during the last decade. Especially, reaction based fluorescent probes have been proven to be highly selective for specific analytes. This review highlights our recent progress on fluorescent imaging probes for biologically important species, such as biothiols, reactive oxygen species, reactive nitrogen species, metal ions including Zn2+, Hg2+, Cu2+ and Au3+, and anions including cyanide and adenosine triphosphate (ATP). PMID:26402684

  2. Carbon nanoparticle-based fluorescent bioimaging probes

    National Research Council Canada - National Science Library

    Bhunia, Susanta Kumar; Saha, Arindam; Maity, Amit Ranjan; Ray, Sekhar C; Jana, Nikhil R

    2013-01-01

    Fluorescent nanoparticle-based imaging probes have advanced current labelling technology and are expected to generate new medical diagnostic tools based on their superior brightness and photostability...

  3. Fluorescent Quantum Dots for Biological Labeling

    Science.gov (United States)

    McDonald, Gene; Nadeau, Jay; Nealson, Kenneth; Storrie-Lomardi, Michael; Bhartia, Rohit

    2003-01-01

    Fluorescent semiconductor quantum dots that can serve as "on/off" labels for bacteria and other living cells are undergoing development. The "on/off" characterization of these quantum dots refers to the fact that, when properly designed and manufactured, they do not fluoresce until and unless they come into contact with viable cells of biological species that one seeks to detect. In comparison with prior fluorescence-based means of detecting biological species, fluorescent quantum dots show promise for greater speed, less complexity, greater sensitivity, and greater selectivity for species of interest. There are numerous potential applications in medicine, environmental monitoring, and detection of bioterrorism.

  4. Two-Photon Fluorescence Microscope for Microgravity Research

    Science.gov (United States)

    Fischer, David G.; Zimmerli, Gregory A.; Asipauskas, Marius

    2005-01-01

    A two-photon fluorescence microscope has been developed for the study of biophysical phenomena. Two-photon microscopy is a novel form of laser-based scanning microscopy that enables three-dimensional imaging without many of the problems inherent in confocal microscopy. Unlike one-photon optical microscopy, two-photon microscopy utilizes the simultaneous nonlinear absorption of two near-infrared photons. However, the efficiency of two-photon absorption is much lower than that of one-photon absorption, so an ultra-fast pulsed laser source is typically employed. On the other hand, the critical energy threshold for two-photon absorption leads to fluorophore excitation that is intrinsically localized to the focal volume. Consequently, two-photon microscopy enables optical sectioning and confocal performance without the need for a signal-limiting pinhole. In addition, there is a reduction (relative to one-photon optical microscopy) in photon-induced damage because of the longer excitation wavelength. This reduction is especially advantageous for in vivo studies. Relative to confocal microscopy, there is also a reduction in background fluorescence, and, because of a reduction in Rayleigh scattering, there is a 4 increase of penetration depth. The prohibitive cost of a commercial two-photon fluorescence-microscope system, as well as a need for modularity, has led to the construction of a custom-built system (see Figure 1). This system includes a coherent mode-locked titanium: sapphire laser emitting 120-fs-duration pulses at a repetition rate of 80 MHz. The pulsed laser has an average output power of 800 mW and a wavelength tuning range of 700 to 980 nm, enabling the excitation of a variety of targeted fluorophores. The output from the laser is attenuated, spatially filtered, and then directed into a confocal scanning head that has been modified to provide for side entry of the laser beam. The laser output coupler has been replaced with a dichroic filter that reflects the

  5. Absorption reconstruction improves biodistribution assessment of fluorescent nanoprobes using hybrid Fluorescence-mediated tomography

    NARCIS (Netherlands)

    Gremse, F.; Theek, B.; Kunjachan, S.; Lederle, W.; Pardo, A.; Barth, S.; Lammers, Twan Gerardus Gertudis Maria; Naumann, U.; Kiessling, F.

    2014-01-01

    Aim: Fluorescence-mediated tomography (FMT) holds potential for accelerating diagnostic and theranostic drug development. However, for proper quantitative fluorescence reconstruction, knowledge on optical scattering and absorption, which are highly heterogeneous in different (mouse) tissues, is

  6. Synchrotron-based X-ray fluorescence microscopy enables multiscale spatial visualization of ions involved in fungal lignocellulose deconstruction

    Science.gov (United States)

    Grant T. Kirker; Samuel Zelinka; Sophie-Charlotte Gleber; David Vine; Lydia Finney; Si Chen; Young Pyo Hong; Omar Uyarte; Stefan Vogt; Jody Jellison; Barry Goodell; Joseph E. Jakes

    2017-01-01

    The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fungal metabolism, has implications for diverse research disciplines ranging from plant pathology and forest ecology, to carbon sequestration. Despite the importance of ions in fungal decay mechanisms, the spatial distribution and quantification of ions in lignocellulosic cell...

  7. Digitally synchronized LCD projector for multi-color fluorescence excitation in parallel capillary electrophoresis detection.

    Science.gov (United States)

    Lin, Shi-Wei; Chang, Chih-Hang; Wu, Dai-Yang; Lin, Che-Hsin

    2010-10-15

    A simple method is proposed for modulating the excitation light used for multi-color fluorescence detection in a single capillary electrophoresis (CE) channel. In the proposed approach, a low-cost commercial liquid crystal device (LCD) projector with digitally-modulated LCD switches is used to provide the illumination light source and the fluorescence emitted from the CE chip is synchronously detected using an ultraviolet-visible-near infrared (UV-vis-NIR) spectrometer. The modulated light source enables the detection of multiple fluorescence signals within a single CE channel without the need of mechanically switching optical components. In order to enhance the sensing performance of the proposed system, two short-pass filters and one band-pass filter are inserted into the LCD projector to modify the wavelength spectra for fluorescence excitation. With this simple approach, the signal-to-noise (SN) ratio of the fluorescence detection signals is greatly improved by a factor of approximately 22 when detecting Atto647N fluorescent dye. The feasibility of the proposed multi-color CE detection approach is demonstrated by detecting two different samples including a mixed sample comprising FITC, Rhodamine B and Atto647N fluorescent dyes and a bio-sample composed of two ssDNAs labeled with FITC and Cy3, respectively. Results confirm that the digitally-modulated excitation system proposed in this study has significant potential for the parallel analysis of fluorescently-labeled bio-samples using a multi-color detection scheme. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

    OpenAIRE

    In-Suck Baek; Moon S. Kim; Hoosoo Lee; Wang-Hee Lee; Byoung-Kwan Cho

    2014-01-01

    A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA) was applied to the fluorescence emission spectra of all regions at 4...

  9. Enabling a Scientific Cloud Marketplace: VGL (Invited)

    Science.gov (United States)

    Fraser, R.; Woodcock, R.; Wyborn, L. A.; Vote, J.; Rankine, T.; Cox, S. J.

    2013-12-01

    The Virtual Geophysics Laboratory (VGL) provides a flexible, web based environment where researchers can browse data and use a variety of scientific software packaged into tool kits that run in the Cloud. Both data and tool kits are published by multiple researchers and registered with the VGL infrastructure forming a data and application marketplace. The VGL provides the basic work flow of Discovery and Access to the disparate data sources and a Library for tool kits and scripting to drive the scientific codes. Computation is then performed on the Research or Commercial Clouds. Provenance information is collected throughout the work flow and can be published alongside the results allowing for experiment comparison and sharing with other researchers. VGL's "mix and match" approach to data, computational resources and scientific codes, enables a dynamic approach to scientific collaboration. VGL allows scientists to publish their specific contribution, be it data, code, compute or work flow, knowing the VGL framework will provide other components needed for a complete application. Other scientists can choose the pieces that suit them best to assemble an experiment. The coarse grain workflow of the VGL framework combined with the flexibility of the scripting library and computational toolkits allows for significant customisation and sharing amongst the community. The VGL utilises the cloud computational and storage resources from the Australian academic research cloud provided by the NeCTAR initiative and a large variety of data accessible from national and state agencies via the Spatial Information Services Stack (SISS - http://siss.auscope.org). VGL v1.2 screenshot - http://vgl.auscope.org

  10. Integrated and Intelligent Manufacturing: Perspectives and Enablers

    Directory of Open Access Journals (Sweden)

    Yubao Chen

    2017-10-01

    Full Text Available With ever-increasing market competition and advances in technology, more and more countries are prioritizing advanced manufacturing technology as their top priority for economic growth. Germany announced the Industry 4.0 strategy in 2013. The US government launched the Advanced Manufacturing Partnership (AMP in 2011 and the National Network for Manufacturing Innovation (NNMI in 2014. Most recently, the Manufacturing USA initiative was officially rolled out to further “leverage existing resources... to nurture manufacturing innovation and accelerate commercialization” by fostering close collaboration between industry, academia, and government partners. In 2015, the Chinese government officially published a 10-year plan and roadmap toward manufacturing: Made in China 2025. In all these national initiatives, the core technology development and implementation is in the area of advanced manufacturing systems. A new manufacturing paradigm is emerging, which can be characterized by two unique features: integrated manufacturing and intelligent manufacturing. This trend is in line with the progress of industrial revolutions, in which higher efficiency in production systems is being continuously pursued. To this end, 10 major technologies can be identified for the new manufacturing paradigm. This paper describes the rationales and needs for integrated and intelligent manufacturing (i2M systems. Related technologies from different fields are also described. In particular, key technological enablers, such as the Internet of Things and Services (IoTS, cyber-physical systems (CPSs, and cloud computing are discussed. Challenges are addressed with applications that are based on commercially available platforms such as General Electric (GE’s Predix and PTC’s ThingWorx.

  11. "Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

    2008-06-12

    ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

  12. Cusps enable line attractors for neural computation

    Science.gov (United States)

    Xiao, Zhuocheng; Zhang, Jiwei; Sornborger, Andrew T.; Tao, Louis

    2017-11-01

    Line attractors in neuronal networks have been suggested to be the basis of many brain functions, such as working memory, oculomotor control, head movement, locomotion, and sensory processing. In this paper, we make the connection between line attractors and pulse gating in feed-forward neuronal networks. In this context, because of their neutral stability along a one-dimensional manifold, line attractors are associated with a time-translational invariance that allows graded information to be propagated from one neuronal population to the next. To understand how pulse-gating manifests itself in a high-dimensional, nonlinear, feedforward integrate-and-fire network, we use a Fokker-Planck approach to analyze system dynamics. We make a connection between pulse-gated propagation in the Fokker-Planck and population-averaged mean-field (firing rate) models, and then identify an approximate line attractor in state space as the essential structure underlying graded information propagation. An analysis of the line attractor shows that it consists of three fixed points: a central saddle with an unstable manifold along the line and stable manifolds orthogonal to the line, which is surrounded on either side by stable fixed points. Along the manifold defined by the fixed points, slow dynamics give rise to a ghost. We show that this line attractor arises at a cusp catastrophe, where a fold bifurcation develops as a function of synaptic noise; and that the ghost dynamics near the fold of the cusp underly the robustness of the line attractor. Understanding the dynamical aspects of this cusp catastrophe allows us to show how line attractors can persist in biologically realistic neuronal networks and how the interplay of pulse gating, synaptic coupling, and neuronal stochasticity can be used to enable attracting one-dimensional manifolds and, thus, dynamically control the processing of graded information.

  13. Improved monomeric red, orange and yellow fluorescent proteins derived from Discosoma sp. red fluorescent protein

    NARCIS (Netherlands)

    Shaner, Nathan C; Campbell, Robert E; Steinbach, Paul A; Giepmans, Ben N G; Palmer, Amy E; Tsien, Roger Y

    2004-01-01

    Fluorescent proteins are genetically encoded, easily imaged reporters crucial in biology and biotechnology. When a protein is tagged by fusion to a fluorescent protein, interactions between fluorescent proteins can undesirably disturb targeting or function. Unfortunately, all wild-type yellow-to-red

  14. Optimal fluorescence waveband determination for detecting defect cherry tomatoes using fluorescence excitation-emission matrix

    Science.gov (United States)

    A multi-spectral fluorescence imaging technique was used to detect defect cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface, and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-...

  15. Correlative super-resolution fluorescence and electron microscopy using conventional fluorescent proteins in vacuo.

    Science.gov (United States)

    Peddie, Christopher J; Domart, Marie-Charlotte; Snetkov, Xenia; O'Toole, Peter; Larijani, Banafshe; Way, Michael; Cox, Susan; Collinson, Lucy M

    2017-08-01

    Super-resolution light microscopy, correlative light and electron microscopy, and volume electron microscopy are revolutionising the way in which biological samples are examined and understood. Here, we combine these approaches to deliver super-accurate correlation of fluorescent proteins to cellular structures. We show that YFP and GFP have enhanced blinking properties when embedded in acrylic resin and imaged under partial vacuum, enabling in vacuo single molecule localisation microscopy. In conventional section-based correlative microscopy experiments, the specimen must be moved between imaging systems and/or further manipulated for optimal viewing. These steps can introduce undesirable alterations in the specimen, and complicate correlation between imaging modalities. We avoided these issues by using a scanning electron microscope with integrated optical microscope to acquire both localisation and electron microscopy images, which could then be precisely correlated. Collecting data from ultrathin sections also improved the axial resolution and signal-to-noise ratio of the raw localisation microscopy data. Expanding data collection across an array of sections will allow 3-dimensional correlation over unprecedented volumes. The performance of this technique is demonstrated on vaccinia virus (with YFP) and diacylglycerol in cellular membranes (with GFP). Copyright © 2017. Published by Elsevier Inc.

  16. Variable color temperature fluorescent lamp

    Science.gov (United States)

    Ravi, J.; Maya, J.

    2000-05-01

    Color temperature change in a mercury-rare gas low pressure discharge has been investigated. Different pulse waveforms have been employed to increase the ratio of mercury upper level transitions with respect to the resonant 254 nm radiation. Low pressure fluorescent light sources were made with coatings consisting of a blue phosphor, sensitive to 365 nm ultraviolet radiation, blended with the standard 254 nm excited red/green phosphors. With a fast rise excitation waveform, a color temperature rise of as much as 1700 K was realized although at a cost of 26% in relative luminous efficacy. An improved scheme for greater color temperature change is proposed based on a phosphor that is excitable by the mercury 185 nm ultraviolet radiation but which does not absorb 254 nm radiation.

  17. ULTRAFINE FLUORESCENT DIAMONDS IN NANOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Kanyuk M. I.

    2014-07-01

    Full Text Available The purpose of the work is to summarize the literature data concerning ultrafine diamonds, namely their industrial production, as well as considerable photostability and biocompatibility that promote their use in modern visualization techniques. It is shown that due to the unique physical properties, they are promising materials for using in nanotechnology in the near future. Possibility of diverse surface modification, small size and large absorption surface are the basis for their use in different approaches for drug and gene delivery into a cell. The changes in the properties of nanodiamond surface modification methods of their creation, stabilization and applications are described. It can be said that fluorescent surface-modified nanodiamonds are a promising target in various research methods that would be widely used for labeling of living cells, as well as in the processes of genes and drugs delivery into a cell.

  18. Sorting drops and cells with acoustics: acoustic microfluidic fluorescence-activated cell sorter.

    Science.gov (United States)

    Schmid, Lothar; Weitz, David A; Franke, Thomas

    2014-10-07

    We describe a versatile microfluidic fluorescence-activated cell sorter that uses acoustic actuation to sort cells or drops at ultra-high rates. Our acoustic sorter combines the advantages of traditional fluorescence-activated cell (FACS) and droplet sorting (FADS) and is applicable for a multitude of objects. We sort aqueous droplets, at rates as high as several kHz, into two or even more outlet channels. We can also sort cells directly from the medium without prior encapsulation into drops; we demonstrate this by sorting fluorescently labeled mouse melanoma cells in a single phase fluid. Our acoustic microfluidic FACS is compatible with standard cell sorting cytometers, yet, at the same time, enables a rich variety of more sophisticated applications.

  19. Long term storage of virus templated fluorescent materials for sensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Seetharam, Raviraja N; Guerra, Charles; Satir, Peter [Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461 (United States); Blum, Amy Szuchmacher; Soto, Carissa M; Ratna, Banahalli R [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Whitley, Jessica L [Geo-Centers, Incorporated, Newton, MA 02459 (United States); Sapsford, Kim E [George Mason University, 10910 University Boulevard, Manassas, VA 20110 (United States); Chatterji, Anju; Lin Tianwei; Johnson, John E [Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (United States)], E-mail: amy.blum@nrl.navy.mil

    2008-03-12

    Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications.

  20. Olive oil DNA fingerprinting by multiplex SNP genotyping on fluorescent microspheres.

    Science.gov (United States)

    Kalogianni, Despina P; Bazakos, Christos; Boutsika, Lemonia M; Targem, Mehdi Ben; Christopoulos, Theodore K; Kalaitzis, Panagiotis; Ioannou, Penelope C

    2015-04-01

    Olive oil cultivar verification is of primary importance for the competitiveness of the product and the protection of consumers and producers from fraudulence. Single-nucleotide polymorphisms (SNPs) have emerged as excellent DNA markers for authenticity testing. This paper reports the first multiplex SNP genotyping assay for olive oil cultivar identification that is performed on a suspension of fluorescence-encoded microspheres. Up to 100 sets of microspheres, with unique "fluorescence signatures", are available. Allele discrimination was accomplished by primer extension reaction. The reaction products were captured via hybridization on the microspheres and analyzed, within seconds, by a flow cytometer. The "fluorescence signature" of each microsphere is assigned to a specific allele, whereas the signal from a reporter fluorophore denotes the presence of the allele. As a model, a panel of three SNPs was chosen that enabled identification of five common Greek olive cultivars (Adramytini, Chondrolia Chalkidikis, Kalamon, Koroneiki, and Valanolia).

  1. Long term storage of virus templated fluorescent materials for sensing applications

    Science.gov (United States)

    Seetharam, Raviraja N.; Szuchmacher Blum, Amy; Soto, Carissa M.; Whitley, Jessica L.; Sapsford, Kim E.; Chatterji, Anju; Lin, Tianwei; Johnson, John E.; Guerra, Charles; Satir, Peter; Ratna, Banahalli R.

    2008-03-01

    Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications.

  2. A BIOSENSOR USING COUPLED PLASMON WAVEGUIDE RESONANCE COMBINED WITH HYPERSPECTRAL FLUORESCENCE ANALYSIS

    Directory of Open Access Journals (Sweden)

    CHAN DU

    2014-01-01

    Full Text Available We developed a biosensor that is capable for simultaneous surface plasmon resonance (SPR sensing and hyperspectral fluorescence analysis in this paper. A symmetrical metal-dielectric slab scheme is employed for the excitation of coupled plasmon waveguide resonance (CPWR in the present work. Resonance between surface plasmon mode and the guided waveguide mode generates narrower full width half-maximum of the reflective curves which leads to increased precision for the determination of refractive index over conventional SPR sensors. In addition, CPWR also offers longer surface propagation depths and higher surface electric field strengths that enable the excitation of fluorescence with hyperspectral technique to maintain an appreciable signal-to-noise ratio. The refractive index information obtained from SPR sensing and the chemical properties obtained through hyperspectral fluorescence analysis confirm each other to exclude false-positive or false-negative cases. The sensor provides a comprehensive understanding of the biological events on the sensor chips.

  3. A microfocus X-ray fluorescence beamline at Indus-2 synchrotron radiation facility.

    Science.gov (United States)

    Tiwari, M K; Gupta, P; Sinha, A K; Kane, S R; Singh, A K; Garg, S R; Garg, C K; Lodha, G S; Deb, S K

    2013-03-01

    A microfocus X-ray fluorescence spectroscopy beamline (BL-16) at the Indian synchrotron radiation facility Indus-2 has been constructed with an experimental emphasis on environmental, archaeological, biomedical and material science applications involving heavy metal speciation and their localization. The beamline offers a combination of different analytical probes, e.g. X-ray fluorescence mapping, X-ray microspectroscopy and total-external-reflection fluorescence characterization. The beamline is installed on a bending-magnet source with a working X-ray energy range of 4-20 keV, enabling it to excite K-edges of all elements from S to Nb and L-edges from Ag to U. The optics of the beamline comprises of a double-crystal monochromator with Si(111) symmetric and asymmetric crystals and a pair of Kirkpatrick-Baez focusing mirrors. This paper describes the performance of the beamline and its capabilities with examples of measured results.

  4. Modern fluorescent techniques to investigate the mechanisms of lymphocyte activation

    Directory of Open Access Journals (Sweden)

    G. A. Liubchenko

    2015-02-01

    Full Text Available Fluorescent proteins are promising tools for studying intracellular signaling processes in lymphocytes. This brief review summarizes fluorescence-based imaging techniques developed in recent years and discusses new methodological advances, such as fluorescent photoswitches, fluorescence recovery after photobleaching (FRAP, fluorescent resonance energy transfer (FRET, fluorescence lifetime imaging microscopy (FLIM, photoactivated localization microscopy (PALM, stochastic optical reconstruction microscopy (STORM, stimulated emission depletion (STED, total internal reflection fluorescence (TIRF and other techiques. This survey also highlights recent advances in vitro imaging of live tissues, novel applications of flow cytometry with genetically modified fluorescent proteins, and future prospects for the development of new immunological test systems based on fluorescent protein technology.

  5. Patterning pallet arrays for cell selection based on high-resolution measurements of fluorescent biosensors.

    Science.gov (United States)

    Shadpour, Hamed; Zawistowski, Jon S; Herman, Annadele; Hahn, Klaus; Allbritton, Nancy L

    2011-06-24

    Pallet arrays enable cells to be separated while they remain adherent to a surface and provide a much greater range of cell selection criteria relative to that of current technologies. However there remains a need to further broaden cell selection criteria to include dynamic intracellular signaling events. To demonstrate the feasibility of measuring cellular protein behavior on the arrays using high resolution microscopy, the surfaces of individual pallets were modified to minimize the impact of scattered light at the pallet edges. The surfaces of the three-dimensional pallets on an array were patterned with a coating such as fibronectin using a customized stamping tool. Micropatterns of varying shape and size were printed in designated regions on the pallets in single or multiple steps to demonstrate the reliability and precision of patterning molecules on the pallet surface. Use of a fibronectin matrix stamped at the center of each pallet permitted the localization of H1299 and mouse embryonic fibroblast (MEF) cells to the pallet centers and away from the edges. Compared to pallet arrays with fibronectin coating the entire top surface, arrays with a central fibronectin pattern increased the percentage of cells localized to the pallet center by 3-4-fold. Localization of cells to the pallet center also enabled the physical separation of cells from optical artifacts created by the rough pallet side walls. To demonstrate the measurement of dynamic intracellular signaling on the arrays, fluorescence measurements of high spatial resolution were performed using a RhoA GTPase biosensor. This biosensor utilized fluorescence resonance energy transfer (FRET) between cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) to measure localized RhoA activity in cellular ruffles at the cell periphery. These results demonstrated the ability to perform spatially resolved measurements of fluorescence-based sensors on the pallet arrays. Thus, the patterned pallet arrays

  6. Bioblendstocks that Enable High Efficiency Engine Designs

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Robert L.; Fioroni, Gina M.; Ratcliff, Matthew A.; Zigler, Bradley T.; Farrell, John

    2016-11-03

    The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel

  7. Hydrologic Prediction Through Earthcube Enabled Hydrogeophysical Cyberinfrastructure

    Science.gov (United States)

    Versteeg, R. J.; Johnson, D.

    2012-12-01

    to "develop a framework to understand and predict responses of the Earth as a system— from the space-atmosphere boundary to the core, including the influences of humans and ecosystems." Effective development of hydrologic prediction tools will require the hydrogeophysical community to engage in and become conversant with the cyberinfrastructure community. In my presentation I will provide several examples of how such tools could look like, and what some of the opportunities are for getting this engagement going and develop cyberinfrastructure enabled hydrologic prediction tools.

  8. An instrument for fast acquisition of fluorescence decay curves at picosecond resolution designed for "double kinetics" experiments: application to fluorescence resonance excitation energy transfer study of protein folding.

    Science.gov (United States)

    Ishay, Eldad Ben; Hazan, Gershon; Rahamim, Gil; Amir, Dan; Haas, Elisha

    2012-08-01

    The information obtained by studying fluorescence decay of labeled biopolymers is a major resource for understanding the dynamics of their conformations and interactions. The lifetime of the excited states of probes attached to macromolecules is in the nanosecond time regime, and hence, a series of snapshot decay curves of such probes might - in principle - yield details of fast changes of ensembles of labeled molecules down to sub-microsecond time resolution. Hence, a major current challenge is the development of instruments for the low noise detection of fluorescence decay curves within the shortest possible time intervals. Here, we report the development of an instrument, picosecond double kinetics apparatus, that enables recording of multiple fluorescence decay curves with picosecond excitation pulses over wide spectral range during microsecond data collection for each curve. The design is based on recording and averaging multiphoton pulses of fluorescence decay using a fast 13 GHz oscilloscope during microsecond time intervals at selected time points over the course of a chemical reaction or conformational transition. We tested this instrument in a double kinetics experiment using reference probes (N-acetyl-tryptophanamide). Very low stochastic noise level was attained, and reliable multi-parameter analysis such as derivation of distance distributions from time resolved FRET (fluorescence resonance excitation energy transfer) measurements was achieved. The advantage of the pulse recording and averaging approach used here relative to double kinetics methods based on the established time correlated single photon counting method, is that in the pulse recording approach, averaging of substantially fewer kinetic experiments is sufficient for obtaining the data. This results in a major reduction in the consumption of labeled samples, which in many cases, enables the performance of important experiments that were not previously feasible.

  9. Exploring the role of leadership in enabling contextual ambidexterity

    NARCIS (Netherlands)

    Havermans, L.A.; Den Hartog, D.N.; Keegan, A.E.; Uhl-Bien, M.

    2015-01-01

    Sustainable success calls for contextually ambidextrous organizing. According to theory, this entails enabling simultaneous high levels of exploration and exploitation within a subsystem. The practices involved in enabling contextual ambidexterity form a major and relatively unexplored leadership

  10. Luminance Analysis of Linear Fluorescent Lamp

    OpenAIRE

    Štěpánek, J.

    2015-01-01

    My paper deals with theme of luminance analysis. The aim of the paper is to find out how change luminance of linear fluorescent lamps with the change of light source position. Linear fluorescent lamp will be measured in horizontal position and in vertical position. Digital camera will be used for measurement. Paper is divided into theoretical part and into practical part.

  11. Agreement between direct fluorescent microscopy and Ziehl ...

    African Journals Online (AJOL)

    Background: The sensitivity of smear microscopy for diagnosis of tuberculosis might be improved through treatment of sputum with sodium hypochlorite and application of fluorescent microscopy. This study aimed to determine the agreement between direct Fluorescent Microscopy and Ziehl-Neelsen concentration technique ...

  12. Fluorescence lifetime imaging using light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Gordon T; Munro, Ian; Poher, Vincent; French, Paul M W; Neil, Mark A A [Blackett Laboratory, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Elson, Daniel S [Institute of Biomedical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Hares, Jonathan D [Kentech Instruments Ltd, Unit 9, Hall Farm Workshops, South Moreton, Didcot, Oxfordshire, OX11 9AG (United Kingdom)], E-mail: gordon.kennedy@imperial.ac.uk

    2008-05-07

    We demonstrate flexible use of low cost, high-power light emitting diodes as illumination sources for fluorescence lifetime imaging (FLIM). Both time-domain and frequency-domain techniques have been implemented at wavelengths spanning the range 450-640 nm. Additionally, we demonstrate optically sectioned fluorescence lifetime imaging by combining structured illumination with frequency-domain FLIM.

  13. A sensitive fluorescent sensor of lanthanide ions

    CERN Document Server

    Bekiari, V; Lianos, P

    2003-01-01

    A fluorescent probe bearing a diazostilbene chromophore and a benzo-15-crown-5 ether moiety is a very efficient sensor of lanthanide ions. The ligand emits strong fluorescence only in the presence of specific ions, namely lanthanide ions, while the emission wavelength is associated with a particular ion providing high sensitivity and resolution.

  14. Bridging fluorescence microscopy and electron microscopy

    NARCIS (Netherlands)

    Giepmans, Ben N. G.

    Development of new fluorescent probes and fluorescence microscopes has led to new ways to study cell biology. With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community. A major

  15. Synthesis and characterization of multicolour fluorescent ...

    Indian Academy of Sciences (India)

    In this study, we successfully developed Y 2 O 3 nanoparticles doped with Tb 3 + and Eu 3 + ions to generate fluorescent images of latent fingerprints. The optical and structural characterization of the nanoparticles was carried out and the fluorescence mechanisms are discussed. In our studies, the developed nanoparticles ...

  16. Examining Thermally Sprayed Coats By Fluorescence Microscopy

    Science.gov (United States)

    Street, Kenneth W., Jr.; Leonhardt, Todd A.

    1994-01-01

    True flaws distinquished from those induced by preparation of specimens. Fluorescence microscopy reveals debonding, porosity, cracks, and other flaws in specimens of thermally sprayed coating materials. Specimen illuminated, and dye it contains fluoresces, emitting light at different wavelength. Filters emphasize contrast between excitation light and emission light. Specimen viewed directly or photographed on color film.

  17. FLUORESCENCE IN DISSOLVED FRACTIONS OF HUMAN ENAMEL

    NARCIS (Netherlands)

    HAFSTROMBJORKMAN, U; SUNDSTROM, F; TENBOSCH, JJ

    Fluorescence induced by laser light is useful in early detection of enamel caries. The present work studied the fluorescence emission pattern in dissolved human enamel and in different molecular weight fractions obtained after gel chromatography or dialysis followed by ultrafiltration. For

  18. Design of fluorescent materials for chemical sensing

    NARCIS (Netherlands)

    Basabe Desmonts, M.L.; Reinhoudt, David; Crego Calama, Mercedes

    2007-01-01

    There is an enormous demand for chemical sensors for many areas and disciplines. High sensitivity and ease of operation are two main issues for sensor development. Fluorescence techniques can easily fulfill these requirements and therefore fluorescent-based sensors appear as one of the most

  19. Absorbance and fluorescence studies on porphyrin Nanostructures ...

    African Journals Online (AJOL)

    The aim of this work was to study some photophysical properties of PNR for application as light harvester in dye sensitized solar cells. These properties included absorbance, fluorescence, and fluorescence quantum yield and lifetime. The results of Transmission Electron Microscope (TEM) images showed the formation of ...

  20. Synthesis and characterization of multicolour fluorescent ...

    Indian Academy of Sciences (India)

    producing fluorescent images of latent fingerprints in shades of green, red and yellow with high-contrast colour under ultraviolet lighting. Keywords. Fingerprint; nanocrystals; rare-earths; fluorescence. 1. Introduction. The search for latent fingerprints at crime scenes is already a routine long present in the forensic science.

  1. Hydrophilic fluorescent nanogel thermometer for intracellular thermometry.

    Science.gov (United States)

    Gota, Chie; Okabe, Kohki; Funatsu, Takashi; Harada, Yoshie; Uchiyama, Seiichi

    2009-03-04

    The first methodology to measure intracellular temperature is described. A highly hydrophilic fluorescent nanogel thermometer developed for this purpose stays in the cytoplasm and emits stronger fluorescence at a higher temperature. Thus, intracellular temperature variations associated with biological processes can be monitored by this novel thermometer with a temperature resolution of better than 0.5 degrees C.

  2. Lossless Three-Dimensional Parallelization in Digitally Scanned Light-Sheet Fluorescence Microscopy.

    Science.gov (United States)

    Dean, Kevin M; Fiolka, Reto

    2017-08-24

    We introduce a concept that enables parallelized three-dimensional imaging throughout large volumes with isotropic 300-350 nm resolution. By staggering high aspect ratio illumination beams laterally and axially within the depth of focus of a digitally scanned light-sheet fluorescence microscope (LSFM), multiple image planes can be simultaneously imaged with minimal cross-talk and light loss. We present a first demonstration of this concept for parallelized imaging by synthesizing two light-sheets with nonlinear Bessel beams and perform volumetric imaging of fluorescent beads and invasive breast cancer cells. This work demonstrates that in principle any digitally scanned LSFM can be parallelized in a lossless manner, enabling drastically faster volumetric image acquisition rates for a given sample brightness and detector technology.

  3. Hybrid Microfluidic Platform for Multifactorial Analysis Based on Electrical Impedance, Refractometry, Optical Absorption and Fluorescence

    Directory of Open Access Journals (Sweden)

    Fábio M. Pereira

    2016-10-01

    Full Text Available This paper describes the development of a novel microfluidic platform for multifactorial analysis integrating four label-free detection methods: electrical impedance, refractometry, optical absorption and fluorescence. We present the rationale for the design and the details of the microfabrication of this multifactorial hybrid microfluidic chip. The structure of the platform consists of a three-dimensionally patterned polydimethylsiloxane top part attached to a bottom SU-8 epoxy-based negative photoresist part, where microelectrodes and optical fibers are incorporated to enable impedance and optical analysis. As a proof of concept, the chip functions have been tested and explored, enabling a diversity of applications: (i impedance-based identification of the size of micro beads, as well as counting and distinguishing of erythrocytes by their volume or membrane properties; (ii simultaneous determination of the refractive index and optical absorption properties of solutions; and (iii fluorescence-based bead counting.

  4. Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Yilmaz, Hasan

    2016-03-01

    Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

  5. The possibilities of improvement in the sensitivity of cancer fluorescence diagnostics by computer image processing

    Science.gov (United States)

    Ledwon, Aleksandra; Bieda, Robert; Kawczyk-Krupka, Aleksandra; Polanski, Andrzej; Wojciechowski, Konrad; Latos, Wojciech; Sieron-Stoltny, Karolina; Sieron, Aleksander

    2008-02-01

    Background: Fluorescence diagnostics uses the ability of tissues to fluoresce after exposition to a specific wavelength of light. The change in fluorescence between normal and progression to cancer allows to see early cancer and precancerous lesions often missed by white light. Aim: To improve by computer image processing the sensitivity of fluorescence images obtained during examination of skin, oral cavity, vulva and cervix lesions, during endoscopy, cystoscopy and bronchoscopy using Xillix ONCOLIFE. Methods: Function of image f(x,y):R2 --> R 3 was transformed from original color space RGB to space in which vector of 46 values refers to every point labeled by defined xy-coordinates- f(x,y):R2 --> R 46. By means of Fisher discriminator vector of attributes of concrete point analalyzed in the image was reduced according to two defined classes defined as pathologic areas (foreground) and healthy areas (background). As a result the highest four fisher's coefficients allowing the greatest separation between points of pathologic (foreground) and healthy (background) areas were chosen. In this way new function f(x,y):R2 --> R 4 was created in which point x,y corresponds with vector Y, H, a*, c II. In the second step using Gaussian Mixtures and Expectation-Maximisation appropriate classificator was constructed. This classificator enables determination of probability that the selected pixel of analyzed image is a pathologically changed point (foreground) or healthy one (background). Obtained map of probability distribution was presented by means of pseudocolors. Results: Image processing techniques improve the sensitivity, quality and sharpness of original fluorescence images. Conclusion: Computer image processing enables better visualization of suspected areas examined by means of fluorescence diagnostics.

  6. Site Specific Synthesis and in-situ Immobilization of Fluorescent Silver Nanoclusters on DNA Nanoscaffolds Using Tollens Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Suchetan [Arizona State Univ., Tempe, AZ (United States); Varghese, R. [Arizona State Univ., Tempe, AZ (United States); Deng, Z. [Arizona State Univ., Tempe, AZ (United States); Zhao, Z. [Arizona State Univ., Tempe, AZ (United States); Kumar, A. [Arizona State Univ., Tempe, AZ (United States); Yan, Hao [Arizona State Univ., Tempe, AZ (United States); Liu, Yan [Arizona State Univ., Tempe, AZ (United States)

    2011-04-06

    DNA strands with specific sequences and covalently attached sugar moieties were used for the site-specific incorporation of the sugar units on a DNA origami scaffold. This approach enabled the subsequent site-specific synthesis and in situ immobilization of fluorescent Ag clusters at predefined positions on the DNA nanoscaffold by treatment with the Tollens reagent.

  7. Capillary Array Waveguide Amplified Fluorescence Detector for mHealth

    Science.gov (United States)

    Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

    2013-01-01

    Mobile Health (mHealth) analytical technologies are potentially useful for carrying out modern medical diagnostics in resource-poor settings. Effective mHealth devices for underserved populations need to be simple, low cost, and portable. Although cell phone cameras have been used for biodetection, their sensitivity is a limiting factor because currently it is too low to be effective for many mHealth applications, which depend on detection of weak fluorescent signals. To improve the sensitivity of portable phones, a capillary tube array was developed to amplify fluorescence signals using their waveguide properties. An array configured with 36 capillary tubes was demonstrated to have a ~100X increase in sensitivity, lowering the limit of detection (LOD) of mobile phones from 1000 nM to 10 nM for fluorescein. To confirm that the amplification was due to waveguide behavior, we coated the external surfaces of the capillaries with silver. The silver coating interfered with the waveguide behavior and diminished the fluorescence signal, thereby proving that the waveguide behavior was the main mechanism for enhancing optical sensitivity. The optical configuration described here is novel in several ways. First, the use of capillaries waveguide properties to improve detection of weak florescence signal is new. Second we describe here a three dimensional illumination system, while conventional angular laser waveguide illumination is spot (or line), which is functionally one-dimensional illumination, can illuminate only a single capillary or a single column (when a line generator is used) of capillaries and thus inherently limits the multiplexing capability of detection. The planar illumination demonstrated in this work enables illumination of a two dimensional capillary array (e.g. x columns and y rows of capillaries). In addition, the waveguide light propagation via the capillary wall provides a third dimension for illumination along the axis of the capillaries. Such an

  8. Holograms preparation using commercial fluorescent benzyl

    Energy Technology Data Exchange (ETDEWEB)

    Dorantes-GarcIa, V; Olivares-Perez, A; Ordonez-Padilla, M J; Mejias-Brizuela, N Y, E-mail: valdoga@Hotmail.com, E-mail: olivares@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Coordinacion de Optica, Calle Luis Enrique Erro N0 1, Santa Maria Tonantzintla, Puebla (Mexico)

    2011-01-01

    We have been able to make holograms with substances such as fluorescence thought of light blue laser to make transmissions holograms, using ammonium dichromate as photo-sensitizer and polyvinyl alcohol (PVA) as matrix. Ammonium dichromate inhibit the fluorescence properties of inks, both mixed in a (PVA) matrix, but we avoid this chemical reaction and we show the results to use the method of painting hologram with fluorescents ink and we describe how the diffraction efficiency parameter changes as a function of the ink absorbed by the emulsion recorded with the gratings, we got good results, making holographic gratings with a blue light from laser diode 470 nm. And we later were painting with fluorescent ink, integrating fluorescence characteristics to the hologram.

  9. Intense fluorescence of Au 20

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chongqi; Harbich, Wolfgang; Sementa, Luca; Ghiringhelli, Luca; Apra, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Brune, Harald

    2017-08-21

    Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. We show that their fluorescence is an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ =739.2 nm (1.68 eV) for Au20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the HOMO-LUMO diabatic bandgap of the cluster. The cluster shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au20 has only one stable isomer (tetrahedral), therefore our sample is mono-disperse in cluster size and conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorptionand predict both main absorption peaks and intrinsic fluorescence in good agreement with experiment.

  10. Boronic acids for fluorescence imaging of carbohydrates.

    Science.gov (United States)

    Sun, Xiaolong; Zhai, Wenlei; Fossey, John S; James, Tony D

    2016-02-28

    "Fluorescence imaging" is a particularly exciting and rapidly developing area of research; the annual number of publications in the area has increased ten-fold over the last decade. The rapid increase of interest in fluorescence imaging will necessitate the development of an increasing number of molecular receptors and binding agents in order to meet the demand in this rapidly expanding area. Carbohydrate biomarkers are particularly important targets for fluorescence imaging given their pivotal role in numerous important biological events, including the development and progression of many diseases. Therefore, the development of new fluorescent receptors and binding agents for carbohydrates is and will be increasing in demand. This review highlights the development of fluorescence imaging agents based on boronic acids a particularly promising class of receptors given their strong and selective binding with carbohydrates in aqueous media.

  11. Development and testing of hyperbaric atomic force microscopy (AFM) and fluorescence microscopy for biological applications.

    Science.gov (United States)

    D'Agostino, D P; McNally, H A; Dean, J B

    2012-05-01

    A commercially available atomic force microscopy and fluorescence microscope were installed and tested inside a custom-designed hyperbaric chamber to provide the capability to study the effects of hyperbaric gases on biological preparations, including cellular mechanism of oxidative stress. In this report, we list details of installing and testing atomic force microscopy and fluorescence microscopy inside a hyperbaric chamber. The pressure vessel was designed to accommodate a variety of imaging equipment and ensures full functionality at ambient and hyperbaric conditions (≤85 psi). Electrical, gas and fluid lines were installed to enable remote operation of instrumentation under hyperbaric conditions, and to maintain viable biological samples with gas-equilibrated superfusate and/or drugs. Systems were installed for vibration isolation and temperature regulation to maintain atomic force microscopy performance during compression and decompression. Results of atomic force microscopy testing demonstrate sub-nanometre resolution at hyperbaric pressure in dry scans and fluid scans, in both contact mode and tapping mode. Noise levels were less when measurements were taken under hyperbaric pressure with air, helium (He) and nitrogen (N(2) ). Atomic force microscopy and fluorescence microscopy measurements were made on a variety of living cell cultures exposed to hyperbaric gases (He, N(2) , O(2) , air). In summary, atomic force microscopy and fluorescence microscopy were installed and tested for use at hyperbaric pressures and enables the study of cellular and molecular effects of hyperbaric gases and pressure per se in biological preparations. © 2012 The Authors Journal of Microscopy © 2012 Royal Microscopical Society.

  12. Peptide-Stabilized, Fluorescent Silver Nanoclusters: Solid-Phase Synthesis and Screening.

    Science.gov (United States)

    Gregersen, Simon; Vosch, Tom; Jensen, Knud J

    2016-12-19

    Few-atom silver nanoclusters (AgNCs) can exhibit strong fluorescence; however, they require ligands to prevent aggregation into larger nanoparticles. Fluorescent AgNCs in biopolymer scaffolds have so far mainly been synthesized in solution, and peptides have only found limited use compared to DNA. Herein, we demonstrate how solid-phase methods can increase throughput dramatically in peptide ligand screening and in initial evaluation of fluorescence intensity and chemical stability of peptide-stabilized AgNCs (P-AgNCs). 9-Fluorenylmethyloxycarbonyl (Fmoc) solid-phase peptide synthesis on a hydroxymethyl-benzoic acid (HMBA) polyethylene glycol polyacrylamide copolymer (PEGA) resin enabled on-resin screening and evaluation of a peptide library, leading to identification of novel peptide-stabilized, fluorescent AgNCs. Using systematic amino acid substitutions, we synthesized and screened a 144-member library. This allowed us to evaluate the effect of length, charge, and Cys content in peptides used as ligands for AgNC stabilization. The results of this study will enable future spectroscopic studies of these peptide-stabilized AgNCs for bioimaging and other applications. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Enabling performance measurement in a small professional service firm

    NARCIS (Netherlands)

    Groen, B.A.C.; van de Belt, M.; Wilderom, C.P.M.

    2012-01-01

    Purpose - Showing why developing an enabling PMS can be useful to small PSFs and how small PSFs can develop such an enabling PMS. Design/methodology/approach - We used a process-consultation type of action research design. We developed an enabling PMS in close cooperation with the employees of a

  14. Preclinical evaluation of spatial frequency domain-enabled wide-field quantitative imaging for enhanced glioma resection

    Science.gov (United States)

    Sibai, Mira; Fisher, Carl; Veilleux, Israel; Elliott, Jonathan T.; Leblond, Frederic; Roberts, David W.; Wilson, Brian C.

    2017-07-01

    5-Aminolevelunic acid-induced protoporphyrin IX (PpIX) fluorescence-guided resection (FGR) enables maximum safe resection of glioma by providing real-time tumor contrast. However, the subjective visual assessment and the variable intrinsic optical attenuation of tissue limit this technique to reliably delineating only high-grade tumors that display strong fluorescence. We have previously shown, using a fiber-optic probe, that quantitative assessment using noninvasive point spectroscopic measurements of the absolute PpIX concentration in tissue further improves the accuracy of FGR, extending it to surgically curable low-grade glioma. More recently, we have shown that implementing spatial frequency domain imaging with a fluorescent-light transport model enables recovery of two-dimensional images of [PpIX], alleviating the need for time-consuming point sampling of the brain surface. We present first results of this technique modified for in vivo imaging on an RG2 rat brain tumor model. Despite the moderate errors in retrieving the absorption and reduced scattering coefficients in the subdiffusive regime of 14% and 19%, respectively, the recovered [PpIX] maps agree within 10% of the point [PpIX] values measured by the fiber-optic probe, validating its potential as an extension or an alternative to point sampling during glioma resection.

  15. Enhanced ALA-induced fluorescence in hyperparathyroidism.

    Science.gov (United States)

    Prosst, Ruediger L; Schroeter, Lioba; Gahlen, Johannes

    2005-04-04

    Intraoperative localization of parathyroid glands can be challenging especially in minimally invasive surgery. Fluorescence diagnosis using the photosensitizer aminolevulinic acid (ALA) has been described to identify normal parathyroid glands during experimental bilateral neck exploration. The present study evaluated fluorescence differences between hyperplastic and normal parathyroid glands as a precondition for a clinical application of the technique. Polycystic kidney disease (PKD) rats with hyperparathyroidism due to hyperplastic parathyroid glands and Wistar rats with normal parathyroid glands were photosensitized by peritoneal lavage with ALA solution. After surgical exposure of thyroid and parathyroid glands the operative site was observed under blue light conditions using the d-light system to assess fluorescence characteristics of each tissue. Fluorescence intensities of parathyroid glands and surrounding thyroid tissue were measured by spectrometry. Parathyroid hormone in serum of the rats was determined by enzyme-linked immunosorbent assay (ELISA). Observation of the exposed thyroid site showed a subjectively stronger red fluorescence of the parathyroid glands in the PKD rats in comparison to the Wistar rats, whereas thyroid tissue appeared equally fluorescent. In the PKD animals, spectrometric fluorescence intensity was 10 times higher in the parathyroid glands than in the thyroid gland, whereas in the Wistar rats the ratio was 3.2:1. Fluorescence intensity in the parathyroid glands was more than twice in the PKD rats than in the Wistar rats, however slightly lower in the thyroid tissue. ELISA confirmed the pathophysiological change of a hyperparathyroidism with significantly increased serum levels of parathyroid hormone in the PKD rats. Hyperparathyroidism enhances ALA-induced fluorescence of the parathyroid glands. A combined surgical fluorescence strategy may justify a unilateral, minimally invasive approach in selected patients and serve to improve

  16. Semisynthetic fluorescent pH sensors for imaging exocytosis and endocytosis.

    Science.gov (United States)

    Martineau, Magalie; Somasundaram, Agila; Grimm, Jonathan B; Gruber, Todd D; Choquet, Daniel; Taraska, Justin W; Lavis, Luke D; Perrais, David

    2017-11-10

    The GFP-based superecliptic pHluorin (SEP) enables detection of exocytosis and endocytosis, but its performance has not been duplicated in red fluorescent protein scaffolds. Here we describe "semisynthetic" pH-sensitive protein conjugates with organic fluorophores, carbofluorescein, and Virginia Orange that match the properties of SEP. Conjugation to genetically encoded self-labeling tags or antibodies allows visualization of both exocytosis and endocytosis, constituting new bright sensors for these key steps of synaptic transmission.

  17. Semisynthetic fluorescent pH sensors for imaging exocytosis and endocytosis

    OpenAIRE

    Martineau, Magalie; Somasundaram, Agila; Grimm, Jonathan B.; Gruber, Todd D.; Choquet, Daniel; Taraska, Justin W.; Lavis, Luke D.; Perrais, David

    2017-01-01

    The GFP-based superecliptic pHluorin (SEP) enables detection of exocytosis and endocytosis, but its performance has not been duplicated in red fluorescent protein scaffolds. Here we describe “semisynthetic” pH-sensitive protein conjugates with organic fluorophores, carbofluorescein, and Virginia Orange that match the properties of SEP. Conjugation to genetically encoded self-labeling tags or antibodies allows visualization of both exocytosis and endocytosis, constituting new bright sensors fo...

  18. Fluorescence/luminescence circadian imaging of complex tissues at single-cell resolution.

    Science.gov (United States)

    Sellix, Michael T; Currie, Jake; Menaker, Michael; Wijnen, Herman

    2010-06-01

    The use of luciferase reporter genes together with luminescence detection has enabled high frequency monitoring of molecular circadian clock function in living tissues. With the help of an intensified CCD camera combined with an inverted epifluorescence microscope, the authors have established a new imaging strategy that makes use of transgenic cell type-specific expression of fluorescent proteins to identify cells of interest for subsequent circadian luminescence recording at single-cell resolution.

  19. Towards correlative super-resolution fluorescence and electron cryo-microscopy

    OpenAIRE

    Wolff, Georg; Hagen, Christoph; Gr?newald, Kay; Kaufmann, Rainer

    2016-01-01

    Correlative light and electron microscopy (CLEM) has become a powerful tool in life sciences. Particularly cryo-CLEM, the combination of fluorescence cryo-microscopy (cryo-FM) permitting for non-invasive specific multi-colour labelling, with electron cryo-microscopy (cryo-EM) providing the undisturbed structural context at a resolution down to the ?ngstrom range, has enabled a broad range of new biological applications. Imaging rare structures or events in crowded environments, such as inside...

  20. Handheld Fluorescence Resonance Energy Transfer (FRET)-Aptamer Sensor for Bone Markers

    Science.gov (United States)

    Bruno, John G.

    2015-01-01

    Astronauts lose significant bone mass during lengthy space flights. NASA wishes to monitor this bone loss in order to develop nutritional and exercise countermeasures. Operational Technologies Corporation (OpTech) has developed a handheld device that quantifies bone loss in a spacecraft environment. The innovation works by adding fluorescent dyes and quenchers to aptamers to enable pushbutton, one-step bind-and-detect FRET assays that can be freeze-dried, rehydrated with body fluids, and used to quantify bone loss.