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Sample records for real-time fluorescence measurement

  1. Real-time quantitative fluorescence measurement of microscale cell culture analog systems

    NASA Astrophysics Data System (ADS)

    Oh, Taek-il; Kim, Donghyun; Tatosian, Daniel; Sung, Jong Hwan; Shuler, Michael

    2007-02-01

    A microscale cell culture analog (μCCA) is a cell-based lab-on-a-chip assay that, as an animal surrogate, is applied to pharmacological studies for toxicology tests. A μCCA typically comprises multiple chambers and microfluidics that connect the chambers, which represent animal organs and blood flow to mimic animal metabolism more realistically. A μCCA is expected to provide a tool for high-throughput drug discovery. Previously, a portable fluorescence detection system was investigated for a single μCCA device in real-time. In this study, we present a fluorescence-based imaging system that provides quantitative real-time data of the metabolic interactions in μCCAs with an emphasis on measuring multiple μCCA samples simultaneously for high-throughput screening. The detection system is based on discrete optics components, with a high-power LED and a charge-coupled device (CCD) camera as a light source and a detector, for monitoring cellular status on the chambers of each μCCA sample. Multiple samples are characterized mechanically on a motorized linear stage, which is fully-automated. Each μCCA sample has four chambers, where cell lines MES-SA/DX- 5, and MES-SA (tumor cells of human uterus) have been cultured. All cell-lines have been transfected to express the fusion protein H2B-GFP, which is a human histone protein fused at the amino terminus to EGFP. As a model cytotoxic drug, 10 μM doxorubicin (DOX) was used. Real-time quantitative data of the intensity loss of enhanced green fluorescent protein (EGFP) during cell death of target cells have been collected over several minutes to 40 hours. Design issues and improvements are also discussed.

  2. Fluorescently Labeled Cyclodextrin Derivatives as Exogenous Markers for Real-Time Transcutaneous Measurement of Renal Function.

    PubMed

    Huang, Jiaguo; Weinfurter, Stefanie; Pinto, Pedro Caetano; Pretze, Marc; Kränzlin, Bettina; Pill, Johannes; Federica, Rodeghiero; Perciaccante, Rossana; Ciana, Leopoldo Della; Masereeuw, Rosalinde; Gretz, Norbert

    2016-10-19

    Evaluation of renal function is crucial for a number of clinical situations. Here, we reported a novel exogenous fluorescent marker (FITC-HPβCD) to real-time assess renal function by using a transcutaneous fluorescent detection technique. FITC-HPβCD was designed based on the principle of renal clearance of designed drugs. It displays favorable fluorescent properties, high hydrophilicity, low plasma protein binding, and high stability in porcine liver esterase as well as in plasma and nontoxicity. More importantly, FITC-HPβCD can be efficiently and rapidly filtered by glomerulus and completely excreted into urine without proximal tubular reabsorption or secretion in rat models. Additionally, the marker was well-tolerated, with nearly 100% urinary recovery of the given doses, and no metabolism were found. Relying on this novel kidney function marker and transcutaneous devices, we demonstrate a rapid, robust, and convenient approach for real-time assessing renal function without the need of time-consuming blood and urine sample preparation. Our work provides a promising tool for noninvasive real-time monitoring of renal function in vivo.

  3. Real-Time Visualization of Tissue Surface Biochemical Features Derived from Fluorescence Lifetime Measurements

    PubMed Central

    Ma, Dinglong; Bec, Julien; Yankelevich, Diego R.

    2016-01-01

    Fiber based fluorescence lifetime imaging has shown great potential for intraoperative diagnosis and guidance of surgical procedures. Here we describe a novel method addressing a significant challenge for the practical implementation of this technique, i.e. the real-time display of the quantified biochemical or functional tissue properties superimposed on the interrogated area. Specifically, an aiming beam (450 nm) generated by a continuous-wave laser beam was merged with the pulsed fluorescence excitation light in a single delivery/collection fiber and then imaged and segmented using a color-based algorithm. We demonstrate that this approach enables continuous delineation of the interrogated location and dynamic augmentation of the acquired frames with the corresponding fluorescence decay parameters. The method was evaluated on a fluorescence phantom and fresh tissue samples. Current results demonstrate that 34 frames per second can be achieved for augmenting videos of 640×512 pixels resolution. Also we show that the spatial resolution of the fluorescence lifetime map depends on the tissue optical properties, the scanning speed, and the frame rate. The dice similarity coefficient between the fluorescence phantom and the reconstructed maps was estimated to be as high as 93%. The reported method could become a valuable tool for augmenting the surgeon’s field of view with diagnostic information derived from the analysis of fluorescence lifetime data in real-time using handheld, automated, or endoscopic scanning systems. Current method provides also a means for maintaining the tissue light exposure within safety limits. This study provides a framework for using an aiming beam with other point spectroscopy applications. PMID:26890641

  4. Ambient measurements of biological aerosol particles near Killarney, Ireland: a comparison between real-time fluorescence and microscopy techniques

    NASA Astrophysics Data System (ADS)

    Healy, D. A.; Huffman, J. A.; O'Connor, D. J.; Pöhlker, C.; Pöschl, U.; Sodeau, J. R.

    2014-08-01

    Primary biological aerosol particles (PBAPs) can contribute significantly to the coarse particle burden in many environments. PBAPs can thus influence climate and precipitation systems as cloud nuclei and can spread disease to humans, animals, and plants. Measurement data and techniques for PBAPs in natural environments at high time- and size resolution are, however, sparse, and so large uncertainties remain in the role that biological particles play in the Earth system. In this study two commercial real-time fluorescence particle sensors and a Sporewatch single-stage particle impactor were operated continuously from 2 August to 2 September 2010 at a rural sampling location in Killarney National Park in southwestern Ireland. A cascade impactor was operated periodically to collect size-resolved particles during exemplary periods. Here we report the first ambient comparison of a waveband integrated bioaerosol sensor (WIBS-4) with a ultraviolet aerodynamic particle sizer (UV-APS) and also compare these real-time fluorescence techniques with results of fluorescence and optical microscopy of impacted samples. Both real-time instruments showed qualitatively similar behavior, with increased fluorescent bioparticle concentrations at night, when relative humidity was highest and temperature was lowest. The fluorescent particle number from the FL3 channel of the WIBS-4 and from the UV-APS were strongly correlated and dominated by a 3 μm mode in the particle size distribution. The WIBS FL2 channel exhibited particle modes at approx. 1 and 3 μm, and each was correlated with the concentration of fungal spores commonly observed in air samples collected at the site (ascospores, basidiospores, Ganoderma spp.). The WIBS FL1 channel exhibited variable multimodal distributions turning into a broad featureless single mode after averaging, and exhibited poor correlation with fungal spore concentrations, which may be due to the detection of bacterial and non-biological fluorescent

  5. Ambient measurements of biological aerosol particles near Killarney, Ireland: a comparison between real-time fluorescence and microscopy techniques

    NASA Astrophysics Data System (ADS)

    Healy, D. A.; Huffman, J. A.; O'Connor, D. J.; Pöhlker, C.; Pöschl, U.; Sodeau, J. R.

    2014-02-01

    Primary biological aerosol particles (PBAP) can contribute significantly to the coarse particle burden in many environments, may thus influence climate and precipitation systems as cloud nuclei, and can spread disease to humans, animals, and plants. Measurements of PBAP in natural environments taken at high time- and size- resolution are, however, sparse and so large uncertainties remain in the role that biological particles play in the Earth system. In this study two commercial real-time fluorescence particle sensors and a Sporewatch single-stage particle impactor were operated continuously from 2 August to 2 September 2010 at a rural sampling location in Killarney National Park in south western Ireland. A cascade impactor was operated periodically to collect size-resolved particles during exemplary periods. Here we report the first ambient comparison of the waveband integrated bioaerosol sensor (WIBS-4) with the ultraviolet aerodynamic particle sizer (UV-APS) and also compare these real-time fluorescence techniques with results of fluorescence and optical microscopy of impacted samples. Both real-time instruments showed qualitatively similar behaviour, with increased fluorescent bioparticle concentrations at night when relative humidity was highest and temperature was lowest. The fluorescent particle number from the FL3 channel of the WIBS-4 and from the UV-APS were strongly correlated and dominated by a 3 μm mode in the particle size distribution. The WIBS FL2 channel exhibited particle modes at approx. 1 and 3 μm, and each were correlated with the concentration of fungal spores commonly observed in air samples collected at the site (ascospores, basidiospores, Ganoderma spp.). The WIBS FL1 channel exhibited variable multi-modal distributions turning into a broad featureless single mode after averaging and exhibited poor correlation with fungal spore concentrations, which may be due to the detection of bacterial and non-biological fluorescent particles

  6. Aerosol-fluorescence spectrum analyzer: real-time measurement of emission spectra of airborne biological particles

    NASA Astrophysics Data System (ADS)

    Hill, Steven C.; Pinnick, Ronald G.; Nachman, Paul; Chen, Gang; Chang, Richard K.; Mayo, Michael W.; Fernandez, Gilbert L.

    1995-10-01

    We have assembled an aerosol-fluorescence spectrum analyzer (AFS), which can measure the fluorescence spectra and elastic scattering of airborne particles as they flow through a laser beam. The aerosols traverse a scattering cell where they are illuminated with intense (50 kW/cm 2) light inside the cavity of an argon-ion laser operating at 488 nm. This AFS can obtain fluorescence spectra of individual dye-doped polystyrene microspheres as small as 0.5 mu m in diameter. The spectra obtained from microspheres doped with pink and green-yellow dyes are clearly different. We have also detected the fluorescence spectra of airborne particles (although not single particles) made from various

  7. Real-time detection and characterization of individual flowing airborne biological particles: fluorescence spectra and elastic scattering measurements

    NASA Astrophysics Data System (ADS)

    Pan, Yongle; Holler, Stephen; Chang, Richard K.; Hill, Steven C.; Pinnick, Ronald G.; Niles, Stanley; Bottiger, Jerold R.; Bronk, Burt V.

    1999-11-01

    Real-time methods which is reagentless and could detect and partially characterize bioaerosols are of current interest. We present a technique for real-time measurement of UV-excited fluorescence spectra and two-dimensional angular optical scattering (TAOS) from individual flowing biological aerosol particles. The fluorescence spectra have been observed from more than 20 samples including Bacillus subtilis, Escherichia coli, Erwinia herbicola, allergens, dust, and smoke. The S/N and resolution of the spectra are sufficient for observing small lineshape differences among the same type of bioaerosol prepared under different conditions. The additional information from TAOS regarding particle size, shape, and granularity has the potential of aiding in distinguishing bacterial aerosols from other aerosols, such as diesel and cigarette smoke.

  8. Real-time method and apparatus for measuring the temperature of a fluorescing phosphor

    DOEpatents

    Britton, Jr., Charles L.; Beshears, David L.; Simpson, Marc L.; Cates, Michael R.; Allison, Steve W.

    1999-01-01

    A method for determining the temperature of a fluorescing phosphor is provided, together with an apparatus for performing the method. The apparatus includes a photodetector for detecting light emitted by a phosphor irradiated with an excitation pulse and for converting the detected light into an electrical signal. The apparatus further includes a differentiator for differentiating the electrical signal and a zero-crossing discrimination circuit that outputs a pulse signal having a pulse width corresponding to the time period between the start of the excitation pulse and the time when the differentiated electrical signal reaches zero. The width of the output pulse signal is proportional to the decay-time constant of the phosphor.

  9. Design of an instrument for real-time detection of bioaerosols using simultaneous measurement of particle aerodynamic size and intrinsic fluorescence.

    PubMed

    Hairston, P P; Ho, J; Quant, F R

    1997-04-01

    A prototype instrument has been constructed to measure individual airborne particles based on their aerodynamic size and their intrinsic fluorescence at selected excitation and emission wavelength bands. The instrument combines features of an aerodynamic particle sizing device with capabilities similar to those of a liquid flow cytometer. The goal of the instrument is to provide real-time data indicative of particle characteristics, and it is especially targeted to respond to bioaerosols from 0.5 to 10 micrometers (aerodynamic diameter) with intrinsic fluorescence exited at a wavelength of 325 nm and emitting from 420 to 580 nm. This size range covers individual airborne bacteria and bacteria clusters, and the fluorescence sensitivity is selected for biological molecules commonly found in cellular systems, for example, reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] and riboflavin. Initial tests with nebulised Bacillus subtilis var. niger (BG, ATCC 9372) spores have shown that, for both individual spores and spore clumps, a low level of fluorescence is detected from 17% of the particles. This detection percentage is on the same order as previous experiments that have measured viability of about 12% for mechanically dispersed BG spores (Ho and Fisher (1993) Defense Research Establishment Suffield Memorandum 1421) and suggests a need for further investigation into the possible relationship between the detected fluorescence and viability of bacterial spores.

  10. Real-time, in vivo measurement of tissular pO2 through the delayed fluorescence of endogenous protoporphyrin IX during photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Piffaretti, Filippo; Novello, Anna Maria; Kumar, Rajendran Senthil; Forte, Eddy; Paulou, Cédric; Nowak-Sliwinska, Patrycja; van den Bergh, Hubert; Wagnières, Georges

    2012-11-01

    Tissular oxygen concentration plays a key role during photodynamic therapy (PDT). Therefore, monitoring its local oxygen partial pressure (pO2) may help predict and/or control the outcome of a PDT treatment. The first real-time, in vivo measurements of the pO2 in the chicken egg's chorioallantoic membrane, using the delayed fluorescence of photoactivable porphyrins (PAPs), including protoporphyrin IX (PpIX), as monitored with a dedicated optical, fiber-based, time-resolved spectrometer, are reported here. The formation of PAPs/PpIX, photosensitizers of extensive clinical use, was induced in the chicken egg's chorioallantoic membrane (CAM) with aminolevulinic acid. An excellent correlation between the vascular damage induced by PDT and the reduction in tissular pO2 is found. This study suggests that clinical measurement of the pO2 using the PAPs'/PpIX's delayed fluorescence (DF) may be used to individualize in real time the PDT light dose applied.

  11. The influence of PAH concentration and distribution on real-time in situ measurements of petroleum products in soils using laser induced fluorescence

    SciTech Connect

    Douglas, G.S.; Lieberman, S.H.; McGinnis, W.C.; Knowles, D.; Peven, C.

    1995-12-31

    Real-time laser induced fluorescence (LIF) in situ measurements of soil samples provide a reliable and cost-effective screening tool for hydrocarbon site assessments. The site characterization and analysis penetrometer system (SCAPS), is a truck-mounted cone penetrometer probe modified with a sapphire window and connected to a laser by fiber optics. The pulsed nitrogen laser 337-nm excitation source induces fluorescence in polynuclear aromatic hydrocarbons (PAHs), which are present in petroleum products. The fluorescence response of these compounds is measured with a fluorometer. The SCAPS can provide continuous hydrocarbon screening measurements to soil depths greater than 100 feet. Discrete soil samples collected from the SCAPS boreholes were extracted and analyzed for total petroleum hydrocarbons (TPH), by gas chromatography with flame ionization detection (GC/FID), and 16 parent and over 100 alkyl substituted PAH compounds by gas chromatography with mass spectrometry detection (GC/MS). This method provides a basis for evaluating the relationship between TPH and PAH concentrations in the soil samples and laser induced fluorescence measurements from the soil borings.

  12. Real-time method and apparatus for measuring the decay-time constant of a fluorescing phosphor

    DOEpatents

    Britton, Jr., Charles L.; Beshears, David L.; Simpson, Marc L.; Cates, Michael R.; Allison, Steve W.

    1999-01-01

    A method for determining the decay-time constant of a fluorescing phosphor is provided, together with an apparatus for performing the method. The apparatus includes a photodetector for detecting light emitted by a phosphor irradiated with an excitation pulse and for converting the detected light into an electrical signal. The apparatus further includes a differentiator for differentiating the electrical signal and a zero-crossing discrimination circuit that outputs a pulse signal having a pulse width corresponding to the time period between the start of the excitation pulse and the time when the differentiated electrical signal reaches zero. The width of the output pulse signal is proportional to the decay-time constant of the phosphor.

  13. Development of real time detector for fluorescent particles

    SciTech Connect

    Prevost, C.; Vendel, J.; Seigneur, A.

    1997-08-01

    Aerosols tagged by a fluorescent dye are a worthwhile tool within the framework of ventilation and filtration studies. The detection in real time of a specific particulate tracer allows characterization of ventilation behaviour such as air change rate, the determination of a good or bad mixing zone and transfer coefficient, or the determination of the decontamination factor for High Efficiency Particulate Air (HEPA) filters. Generally, these tests require specific aerosols in order to get rid of the atmospheric aerosol background. Until now the principle of fluorescent aerosol concentration measuring has only allowed an integral response with a time lag by means of sampling on filters and a fluorimetric analysis after specific conditioning of these filters. 5 refs., 13 figs.

  14. Effect of the gastrointestinal environment on pH homeostasis of Lactobacillus plantarum and Lactobacillus brevis cells as measured by real-time fluorescence ratio-imaging microscopy.

    PubMed

    Ramos, Cíntia Lacerda; Thorsen, Line; Ryssel, Mia; Nielsen, Dennis S; Siegumfeldt, Henrik; Schwan, Rosane Freitas; Jespersen, Lene

    2014-04-01

    In the present work, an in vitro model of the gastrointestinal tract (GIT) was developed to obtain real-time observations of the pH homeostasis of single cells of probiotic Lactobacillus spp. strains as a measure of their physiological state. Changes in the intracellular pH (pHi) were determined using fluorescence ratio imaging microscopy (FRIM) for potential probiotic strains of Lactobacillus plantarum UFLA CH3 and Lactobacillus brevis UFLA FFC199. Heterogeneous populations were observed, with pHi values ranging from 6.5 to 7.5, 3.5 to 5.6 and 6.5 to 8.0 or higher during passage of saliva (pH 6.4), gastric (pH 3.5) and intestinal juices (pH 6.4), respectively. When nutrients were added to gastric juice, the isolate L. brevis significantly decreased its pH(i) closer to the extracellular pH (pH(ex)) than in gastric juice without nutrients. This was not the case for L. plantarum. This study is the first to produce an in vitro GIT model enabling real-time monitoring of pH homeostasis of single cells in response to the wide range of pH(ex) of the GIT. Furthermore, it was possible to observe the heterogeneous response of single cells. The technique can be used to determine the survival and physiological conditions of potential probiotics and other microorganisms during passage through the GIT.

  15. Hyd5 gene based analysis of cereals and malt for gushing-inducing Fusarium spp. by real-time LAMP using fluorescence and turbidity measurements.

    PubMed

    Denschlag, Carla; Vogel, Rudi F; Niessen, Ludwig

    2013-04-01

    The surface active class 2 hydrophobin Hyd5p (GenBank accession number DQ449530) has been identified as a causative agent for over foaming (gushing) of beer. In order to estimate the potential of brewing cereals and malt to induce gushing in beer we used a previously described set of primers to amplify a partial sequence of the hyd5 gene in Fusarium culmorum and closely related species in a real-time loop-mediated isothermal amplification assay. Real-time LAMP was optimized and performed on two different platforms using a turbidimeter and a fluorescence reader to monitor the reaction on line. Serial dilutions of purified target DNA were used to set up a calibration curve for quantitative estimation of DNA concentrations. Analysis of model barley samples prepared by mixing infected with non-infected material in different ratios demonstrated a positive correlation between the real-time LAMP results and respective infection levels. In order to investigate the performance of the newly established methods, samples of barley were analyzed for their gushing potential using the Hyd5 real-time LAMP assay and a reference in vitro test for gushing prediction (Modified Carlsberg Test, MCT) in parallel experiments. Results showed that the real-time LAMP assay was in accordance with the reference test in 50% of cases with both platforms used. It predicted a lower number of gushing-positive samples as compared to the current reference test.

  16. A Measure of Real-Time Intelligence

    NASA Astrophysics Data System (ADS)

    Gavane, Vaibhav

    2013-03-01

    We propose a new measure of intelligence for general reinforcement learning agents, based on the notion that an agent's environment can change at any step of execution of the agent. That is, an agent is considered to be interacting with its environment in real-time. In this sense, the resulting intelligence measure is more general than the universal intelligence measure (Legg and Hutter, 2007) and the anytime universal intelligence test (Hernández-Orallo and Dowe, 2010). A major advantage of the measure is that an agent's computational complexity is factored into the measure in a natural manner. We show that there exist agents with intelligence arbitrarily close to the theoretical maximum, and that the intelligence of agents depends on their parallel processing capability. We thus believe that the measure can provide a better evaluation of agents and guidance for building practical agents with high intelligence.

  17. Fluorescence based real time monitoring of fouling in process chromatography

    PubMed Central

    Pathak, Mili; Lintern, Katherine; Chopda, Viki; Bracewell, Daniel G.; Rathore, Anurag S.

    2017-01-01

    A real time monitoring of fouling in liquid chromatography has been presented. The versatility of the approach has been proven by successful implementation in three case studies with an error <1%. The first application demonstrates the monitoring of protein A ligand density and foulant concentration for assessing performance of protein A chromatography resin during purification of monoclonal antibodies. The observations have been supported from LC-MS/MS studies that were independently performed. The second application involves monitoring of foulant deposition during multimode cation exchange chromatography based purification of human serum albumin. Finally, in the third application, monitoring of foulants during multimodal hydrophobic interaction chromatography of recombinant human granulocyte colony stimulating factor is demonstrated. In all three cases, it is observed that the fluorescence intensity consistently increases with resin reuse as more foulants are deposited over time. The proposed approach can be readily used for real time monitoring of fouling and process control. PMID:28358349

  18. A Case Study of Upper-Room UVGI in Densely-Occupied Elementary Classrooms by Real-Time Fluorescent Bioaerosol Measurements

    PubMed Central

    Su, Chunxiao; Lau, Josephine; Yu, Fang

    2017-01-01

    Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary school classrooms—a densely occupied environment—along with upper-room ultraviolet germicidal irradiation (UVGI) devices. The classrooms were separated into a UVGI group and a non-UVGI control group. Fluorescent bioaerosol counts (FBCs) were monitored on 20 visiting days over a four-month period. The classroom with upper-room UVGI showed significantly lower concentrations of fine size (<3 μm) and total FBCs than the control classroom during 13 of the 20 visiting days. The results of the study indicate that the upper-room UVGI could be effective in reducing FBCs in the school environment, and RBMs may be applicable in reflecting the transient conditions of the classrooms due to the dynamic activity levels of the students and teachers. PMID:28075352

  19. A Case Study of Upper-Room UVGI in Densely-Occupied Elementary Classrooms by Real-Time Fluorescent Bioaerosol Measurements.

    PubMed

    Su, Chunxiao; Lau, Josephine; Yu, Fang

    2017-01-08

    Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary school classrooms-a densely occupied environment-along with upper-room ultraviolet germicidal irradiation (UVGI) devices. The classrooms were separated into a UVGI group and a non-UVGI control group. Fluorescent bioaerosol counts (FBCs) were monitored on 20 visiting days over a four-month period. The classroom with upper-room UVGI showed significantly lower concentrations of fine size (<3 μm) and total FBCs than the control classroom during 13 of the 20 visiting days. The results of the study indicate that the upper-room UVGI could be effective in reducing FBCs in the school environment, and RBMs may be applicable in reflecting the transient conditions of the classrooms due to the dynamic activity levels of the students and teachers.

  20. Real-time absorption reduced surface fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Tunnell, James W.

    2014-09-01

    We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f=0.5 mm-1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19 frames/s. This technique has potential in cancer visualization and tumor margin detection.

  1. Real-time absorption reduced surface fluorescence imaging.

    PubMed

    Yang, Bin; Tunnell, James W

    2014-09-01

    We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f ¼ 0.5 mm−1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19 frames∕s. This technique has potential in cancer visualization and tumor margin detection.

  2. Real-time fluorescence imaging in analytical chemistry

    NASA Astrophysics Data System (ADS)

    Johansson, Jonas; Johansson, Thomas; Nilsson, Stefan

    1996-01-01

    A detection system for capillary electroseparation methods based on fluorescence imaging has been developed. In capillary electrophoresis (CE) the detection unit is normally placed near the outlet part of the fused silica column where a window is opened in the coating and the fluorescence is recorded over a short distance to maintain a high resolution. Our method employs fluorescence imaging of the whole column during separation of various samples. The column is positioned in a straight holder and the outer protective coating of the column is removed to get optical access to the sample. An excimer/dye laser is used for excitation of the sample and the fluorescence is recorded with an image-intensified CCD detector and displayed in real-time. The CCD detector is read out with a rate of about 5 frames per second and the corresponding full fluorescence line profiles along the column are displayed. Thus, full electropherogram are displayed showing the propagation and gradual separation of the sample fractions. The main advantage of this method is that parameters such as sample concentrations, diffusion, wall interaction and sample-to-sample interaction can be studied in real-time over the full length of the column, which is crucial for efficient system optimization. Among several applications, isoelectric focusing, isotachophoresis and enzyme-substrate interactions can be mentioned. Methods for increasing the collection efficiency, such as fiber optic arrays, have been investigated as well as different methods for computer-assisted signal integration and filtering. A fiber array consisting of 500 optical quartz fibers has been constructed that gives a substantial improvement of the optical collection efficiency.

  3. Quasi-real-time fluorescence imaging with lifetime dependent contrast

    NASA Astrophysics Data System (ADS)

    Jiang, Pei-Chi; Grundfest, Warren S.; Stafsudd, Oscar M.

    2011-08-01

    Conventional fluorescence lifetime imaging requires complicated algorithms to extract lifetimes of fluorophores and acquisition of multiple data points at progressively longer delay times to characterize tissues. To address diminishing signal-to-noise ratios at these progressively longer time delays, we report a time-resolved fluorescence imaging method, normalized fluorescence yield imaging that does not require the extraction of lifetimes. The concept is to extract the ``contrast'' instead of the lifetime value of the fluorophores by using simple mathematical algorithms. This process converts differences in decay times directly to different intensities. The technique was verified experimentally using a gated iCCD camera and an ultraviolet light-emitting diode light source. It was shown that this method can distinguish between chemical dyes (Fluorescein and Rhodamine-B) and biomedical samples, such as powders of elastin and collagen. Good contrast was obtained between fluorophores that varied by less than 6% in lifetime. Additionally, it was shown that long gate times up to 16 ns achieve good contrast depending upon the samples to be studied. These results support the feasibility of time-resolved fluorescence imaging without lifetime extraction, which has a potential clinical role in noninvasive real-time imaging.

  4. Real time optical Biopsy: Time-resolved Fluorescence Spectroscopy instrumentation and validation

    PubMed Central

    Kittle, David S.; Vasefi, Fartash; Patil, Chirag G.; Mamelak, Adam; Black, Keith L.; Butte, Pramod V.

    2016-01-01

    The Time-resolved fluorescence spectroscopy (TR-FS) has the potential to differentiate tumor and normal tissue in real time during surgical excision. In this manuscript, we describe the design of a novel TR-FS device, along with preliminary data on detection accuracy for fluorophores in a mixture. The instrument is capable of near real-time fluorescence lifetime acquisition in multiple spectral bands and analysis. It is also able to recover fluorescence lifetime with sub-20ps accuracy as validated with individual organic fluorescence dyes and dye mixtures yielding lifetime values for standard fluorescence dyes that closely match with published data. We also show that TR-FS is able to quantify the relative concentration of fluorescence dyes in a mixture by the unmixing of lifetime decays. We show that the TR-FS prototype is able to identify in near-real time the concentrations of dyes in a complex mixture based on previously trained data. As a result, we demonstrate that in complex mixtures of fluorophores, the relative concentration information is encoded in the fluorescence lifetime across multiple spectral bands. We show for the first time the temporal and spectral measurements of a mixture of fluorochromes and the ability to differentiate relative concentrations of each fluorochrome mixture in real time. PMID:27929039

  5. Real time optical Biopsy: Time-resolved Fluorescence Spectroscopy instrumentation and validation.

    PubMed

    Kittle, David S; Vasefi, Fartash; Patil, Chirag G; Mamelak, Adam; Black, Keith L; Butte, Pramod V

    2016-12-08

    The Time-resolved fluorescence spectroscopy (TR-FS) has the potential to differentiate tumor and normal tissue in real time during surgical excision. In this manuscript, we describe the design of a novel TR-FS device, along with preliminary data on detection accuracy for fluorophores in a mixture. The instrument is capable of near real-time fluorescence lifetime acquisition in multiple spectral bands and analysis. It is also able to recover fluorescence lifetime with sub-20ps accuracy as validated with individual organic fluorescence dyes and dye mixtures yielding lifetime values for standard fluorescence dyes that closely match with published data. We also show that TR-FS is able to quantify the relative concentration of fluorescence dyes in a mixture by the unmixing of lifetime decays. We show that the TR-FS prototype is able to identify in near-real time the concentrations of dyes in a complex mixture based on previously trained data. As a result, we demonstrate that in complex mixtures of fluorophores, the relative concentration information is encoded in the fluorescence lifetime across multiple spectral bands. We show for the first time the temporal and spectral measurements of a mixture of fluorochromes and the ability to differentiate relative concentrations of each fluorochrome mixture in real time.

  6. Real time optical Biopsy: Time-resolved Fluorescence Spectroscopy instrumentation and validation

    NASA Astrophysics Data System (ADS)

    Kittle, David S.; Vasefi, Fartash; Patil, Chirag G.; Mamelak, Adam; Black, Keith L.; Butte, Pramod V.

    2016-12-01

    The Time-resolved fluorescence spectroscopy (TR-FS) has the potential to differentiate tumor and normal tissue in real time during surgical excision. In this manuscript, we describe the design of a novel TR-FS device, along with preliminary data on detection accuracy for fluorophores in a mixture. The instrument is capable of near real-time fluorescence lifetime acquisition in multiple spectral bands and analysis. It is also able to recover fluorescence lifetime with sub-20ps accuracy as validated with individual organic fluorescence dyes and dye mixtures yielding lifetime values for standard fluorescence dyes that closely match with published data. We also show that TR-FS is able to quantify the relative concentration of fluorescence dyes in a mixture by the unmixing of lifetime decays. We show that the TR-FS prototype is able to identify in near-real time the concentrations of dyes in a complex mixture based on previously trained data. As a result, we demonstrate that in complex mixtures of fluorophores, the relative concentration information is encoded in the fluorescence lifetime across multiple spectral bands. We show for the first time the temporal and spectral measurements of a mixture of fluorochromes and the ability to differentiate relative concentrations of each fluorochrome mixture in real time.

  7. High-power white LED-based system incorporating a CCD Offner imaging spectrometer for real-time fluorescence qPCR measurements

    NASA Astrophysics Data System (ADS)

    Alaruri, Sami D.

    2014-12-01

    An optical system for qPCR fluorescence measurements which incorporates high-power white LEDs, PMMA plastic lenses and an Offner multichannel (imaging) CCD-based spectrometer has been developed and validated. The optical system can detect twenty reaction vessels in an asynchronous manner and up to seven different fluorescent dyes (7 plex) at 1 nM dye concentrations in each of the reaction vessels. Furthermore, PCR curves obtained using the optical measurement system for a genomic deoxyribonucleic acid (DNA) template containing HEX and Texas Red fluorescent probes (fluorophores) are discussed. The spectral resolution, dynamic range and repeatability of the measurement system are < 15 nm, > 3 decades and < 1% CV, respectively.

  8. Continuous flow real-time PCR device using multi-channel fluorescence excitation and detection.

    PubMed

    Hatch, Andrew C; Ray, Tathagata; Lintecum, Kelly; Youngbull, Cody

    2014-02-07

    High throughput automation is greatly enhanced using techniques that employ conveyor belt strategies with un-interrupted streams of flow. We have developed a 'conveyor belt' analog for high throughput real-time quantitative Polymerase Chain Reaction (qPCR) using droplet emulsion technology. We developed a low power, portable device that employs LED and fiber optic fluorescence excitation in conjunction with a continuous flow thermal cycler to achieve multi-channel fluorescence detection for real-time fluorescence measurements. Continuously streaming fluid plugs or droplets pass through tubing wrapped around a two-temperature zone thermal block with each wrap of tubing fluorescently coupled to a 64-channel multi-anode PMT. This work demonstrates real-time qPCR of 0.1-10 μL droplets or fluid plugs over a range of 7 orders of magnitude concentration from 1 × 10(1) to 1 × 10(7). The real-time qPCR analysis allows dynamic range quantification as high as 1 × 10(7) copies per 10 μL reaction, with PCR efficiencies within the range of 90-110% based on serial dilution assays and a limit of detection of 10 copies per rxn. The combined functionality of continuous flow, low power thermal cycling, high throughput sample processing, and real-time qPCR improves the rates at which biological or environmental samples can be continuously sampled and analyzed.

  9. Dual-wavelength-excitation single-particle fluorescence spectrometer/particle sorter for real-time measurement of organic carbon and biological aerosols

    NASA Astrophysics Data System (ADS)

    Pan, Yong-Le; Pinnick, Ron G.; Hill, Steven C.; Huang, Hermes; Chang, Richard K.

    2008-10-01

    We report the development of a Single-Particle Fluorescence Spectrometer (SPFS) system capable of measuring two UV-laser excited fluorescence spectra from a single particle on-the-fly. The two dispersed fluorescence spectra are obtained from excitation by two lasers at different wavelengths (263 nm and 351 nm). The SPFS samples single particles with sizes primarily in the 1-10 μm range. The fluorescence spectra are recorded from 280 nm to 600 nm (in 20 channels) for 263 nm excitation and from 370 nm to 700 nm (in 22 channels) for 351 nm excitation. The elastic scattering (channel 4 and 9) is also recorded for sizing each particle. A time stamp for single particles is marked with a variable time interval resolution from 10 ms to 10 minutes. The SPFS employs a virtual-impactor concentrator to concentrate respirable-sized particles with a resulting (size-dependent) effective flow rate of around 100 liters/min. The SPFS can measure single-particle spectra at a maximum rate of 90,000/sec, although the highest rates we have experienced for the ambient are only several hundred/sec. When the SPFS is combined with an aerodynamic deflector (puffer) to sort particles according to their fluorescence spectral characteristics, the SPFS/puffer system can selectively deflect and collect an enriched sample of targeted particles (at rates limited by the puffer) of 1200 particles/sec, for further examination. In laboratory tests, aerosol particles with similar UV-LIF spectra (e.g. B. subtilis and E.coli) are puffed into the reservoir of a micro-fluidic cell, where fluorescent-labeled antibodies bind to them and were classified by their labeled fluorescence. Measurements of the background ambient aerosol with the SPFS system made at sites with different regional climate (Connecticut, Maryland, and New Mexico) were clustered (unstructured hierarchical analysis) into 8-10 groups, with over 90% of all the fluorescent particles contained within these clusters (threshold dot product=0

  10. Real-Time Imaging of Fluorescent Flagellar Filaments

    PubMed Central

    Turner, Linda; Ryu, William S.; Berg, Howard C.

    2000-01-01

    Bacteria swim by rotating flagellar filaments that are several micrometers long, but only about 20 nm in diameter. The filaments can exist in different polymorphic forms, having distinct values of curvature and twist. Rotation rates are on the order of 100 Hz. In the past, the motion of individual filaments has been visualized by dark-field or differential-interference-contrast microscopy, methods hampered by intense scattering from the cell body or shallow depth of field, respectively. We have found a simple procedure for fluorescently labeling cells and filaments that allows recording their motion in real time with an inexpensive video camera and an ordinary fluorescence microscope with mercury-arc or strobed laser illumination. We report our initial findings with cells of Escherichia coli. Tumbles (events that enable swimming cells to alter course) are remarkably varied. Not every filament on a cell needs to change its direction of rotation: different filaments can change directions at different times, and a tumble can result from the change in direction of only one. Polymorphic transformations tend to occur in the sequence normal, semicoiled, curly 1, with changes in the direction of movement of the cell body correlated with transformations to the semicoiled form. PMID:10781548

  11. Real-Time Imaging of Fluorescent Flagellar Filaments

    NASA Astrophysics Data System (ADS)

    Ryu, William

    2003-03-01

    Bacteria swim by rotating flagellar filaments that are several micrometers long, but only about 18 nm in diameter. The filaments can exist in different polymorphic forms, having distinct values of curvature and twist. Rotation rates are on the order of 100 Hz. In the past, the motion of individual filaments has been visualized by dark-field or differential-interference-contrast microscopy, methods hampered by intense scattering from the cell body or shallow depth of field, respectively. We have found a simple procedure for fluorescently labeling cells and filaments that allows recording their motion in real time with an inexpensive video camera and an ordinary fluorescence microscope with mercury-arc or strobed laser illumination. We report our initial findings with cells of Escherichia coli. Tumbles (events that enable swimming cells to alter course) are remarkably varied. Not every filament on a cell needs to change its direction of rotation: different filaments can change directions at different times, and a tumble can result from the change in direction of only one. Polymorphic transformations tend to occur in the sequence normal, semicoiled, curly 1, with changes in the direction of movement of the cell body correlated with transformations to the semicoiled form.

  12. Portable real-time fluorescence cytometry of microscale cell culture analog devices

    NASA Astrophysics Data System (ADS)

    Kim, Donghyun; Tatosian, Daniel A.; Shuler, Michael L.

    2006-02-01

    A portable fluorescence cytometric system that provides a modular platform for quantitative real-time image measurements has been used to explore the applicability to investigating cellular events on multiple time scales. For a short time scale, we investigated the real-time dynamics of uptake of daunorubicin, a chemotherapeutic agent, in cultured mouse L-cells in a micro cell culture analog compartment using the fluorescent cytometric system. The green fluorescent protein (GFP) expression to monitor induction of pre-specified genes, which occurs on a much longer time scale, has also been measured. Here GFP fluorescence from a doxycycline inducible promoter in a mouse L-cell line was determined. Additionally, a system based on inexpensive LEDs showed performance comparable to a broadband light source based system and reduced photobleaching compared to microscopic examination.

  13. Real-time point-of-care measurement of impaired renal function in a rat acute injury model employing exogenous fluorescent tracer agents

    NASA Astrophysics Data System (ADS)

    Dorshow, Richard B.; Fitch, Richard M.; Galen, Karen P.; Wojdyla, Jolette K.; Poreddy, Amruta R.; Freskos, John N.; Rajagopalan, Raghavan; Shieh, Jeng-Jong; Demirjian, Sevag G.

    2013-02-01

    Renal function assessment is needed for the detection of acute kidney injury and chronic kidney disease. Glomerular filtration rate (GFR) is now widely accepted as the best indicator of renal function, and current clinical guidelines advocate its use in the staging of kidney disease. The optimum measure of GFR is by the use of exogenous tracer agents. However current clinically employed agents lack sensitivity or are cumbersome to use. An exogenous GFR fluorescent tracer agent, whose elimination rate could be monitored noninvasively through skin would provide a substantial improvement over currently available methods. We developed a series of novel aminopyrazine analogs for use as exogenous fluorescent GFR tracer agents that emit light in the visible region for monitoring GFR noninvasively over skin. In rats, these compounds are eliminated by the kidney with urine recovery greater than 90% of injected dose, are not broken down or metabolized in vivo, are not secreted by the renal tubules, and have clearance values similar to a GFR reference compound, iothalamate. In addition, biological half-life of these compounds measured in rats by noninvasive optical methods correlated with plasma derived methods. In this study, we show that this noninvasive methodology with our novel fluorescent tracer agents can detect impaired renal function. A 5/6th nephrectomy rat model is employed.

  14. Near real-time fluorescence detection of beryllium

    SciTech Connect

    McCleskey, T. M.; Ehler, D. S.; Minogue, E. M.; Collis, G. E.; Keizer, T. S.; Burrell, A. K.; Sauer, N. N.; John, K. D.

    2004-01-01

    We report on a fluorescent test for beryllium designed for analyzing swipes. The detection is rapid, quantitative and deployable in the field with $5,000 portable fluorimeter. Swipes are placed in a vial and a dilution solution is added. The vials are then rotated for 30 minutes and then syringe filtered. An aliquot of 100 pL is added to a detector solution and fluorescence measured with a portable ocean optics unit. We can readily detect down to 0.02 {micro}g on a filter paper. Interference studies have been carried out with various metals including Al, Fe, Pb, U, Ca, W, Ni, Co and Cu. The technique has proven to be successful under various conditions including a variety of surfaces both in the lab and in field. It is a user-friendly, cost effective method.

  15. Results of the first-in-human clinical trial for MB-102, a novel fluorescent tracer agent for real-time measurement of glomerular filtration rate

    NASA Astrophysics Data System (ADS)

    Dorshow, Richard B.; Debreczeny, Martin P.; Dowling, Thomas C.

    2015-03-01

    The fluorescent tracer agent 2,5-bis[N-(1-carboxy-2-hydroxy)]carbamoyl-3,6-diaminopyrazine, designated MB-102, has been developed with properties and attributes necessary for use as a direct measure of glomerular filtration rate (GFR). Comparison to known standard exogenous GFR agents in animal models has demonstrated an excellent correlation. A clinical trial to demonstrate this same correlation in humans is in progress. This clinical trial is the first in a series of trials necessary to obtain regulatory clearance from the FDA. We report herein the comparison of plasma pharmacokinetics between MB-102 and the known standard exogenous GFR agent Iohexol in healthy subjects with normal renal function. Post simultaneous administration of both agents, blood samples over a period of 12 hours were collected from each subject to assess pharmacokinetic parameters including GFR. Urine samples were collected over this same period to assess percent injected dose recovered in the urine. Results indicate MB-102 is a GFR agent in humans from the comparison to the standard agent.

  16. Characterization and Quantification of Intact 26S Proteasome Proteins by Real-Time Measurement of Intrinsic Fluorescence Prior to Top-down Mass Spectrometry

    PubMed Central

    Russell, Jason D.; Scalf, Mark; Book, Adam J.; Ladror, Daniel T.; Vierstra, Richard D.; Smith, Lloyd M.; Coon, Joshua J.

    2013-01-01

    Quantification of gas-phase intact protein ions by mass spectrometry (MS) is impeded by highly-variable ionization, ion transmission, and ion detection efficiencies. Therefore, quantification of proteins using MS-associated techniques is almost exclusively done after proteolysis where peptides serve as proxies for estimating protein abundance. Advances in instrumentation, protein separations, and informatics have made large-scale sequencing of intact proteins using top-down proteomics accessible to the proteomics community; yet quantification of proteins using a top-down workflow has largely been unaddressed. Here we describe a label-free approach to determine the abundance of intact proteins separated by nanoflow liquid chromatography prior to MS analysis by using solution-phase measurements of ultraviolet light-induced intrinsic fluorescence (UV-IF). UV-IF is measured directly at the electrospray interface just prior to the capillary exit where proteins containing at least one tryptophan residue are readily detected. UV-IF quantification was demonstrated using commercially available protein standards and provided more accurate and precise protein quantification than MS ion current. We evaluated the parallel use of UV-IF and top-down tandem MS for quantification and identification of protein subunits and associated proteins from an affinity-purified 26S proteasome sample from Arabidopsis thaliana. We identified 26 unique proteins and quantified 13 tryptophan-containing species. Our analyses discovered previously unidentified N-terminal processing of the β6 (PBF1) and β7 (PBG1) subunit - such processing of PBG1 may generate a heretofore unknown additional protease active site upon cleavage. In addition, our approach permitted the unambiguous identification and quantification both isoforms of the proteasome-associated protein DSS1. PMID:23536786

  17. Monitoring temperature with fluorescence during real-time PCR and melting analysis.

    PubMed

    Sanford, Lindsay N; Wittwer, Carl T

    2013-03-01

    Accurate control of the sample temperature during thermal cycling is critical for successful polymerase chain reaction (PCR). Direct sensor contact with the reaction is problematic, forcing measurements external to the sample and compromising accuracy during rapid temperature transitions. The widespread use of fluorescence in real-time PCR and melting analysis suggests another measure of temperature, the intrinsic fluorescence of temperature-sensitive passive dyes. Calibration curves correlating sulforhodamine B fluorescence to temperature on nine real-time PCR instruments were obtained by heating at 0.018-0.1 °C/s between 50 and 95 °C, with a twofold change in fluorescence. After instrument stabilization for 20 min, no dye photobleaching was observed and thermal degradation was 2.2%/h at 80 °C. During cycling, solution temperatures derived from fluorescence were well matched to thermocouples placed within samples, but not to temperatures recorded by the instrument. Solution temperatures lagged instrument temperatures by up to 8 °C during cycling, often requiring 5-10 s at target temperatures for equilibration. Melting curves were displaced by 0.2-1.1 °C. Temperature inaccuracies were dependent on the instrument, the ramp rate, and the sample volume. The fluorescence of passive dyes can be used to accurately assess solution temperatures during PCR and should be particularly useful at fast cycling speeds.

  18. Multiwavelength Photosensor for On-Chip Real-Time Monitoring of Fluorescence and Turbidity

    NASA Astrophysics Data System (ADS)

    Maruyama, Yuki; Ishida, Makoto; Sawada, Kazuaki

    2009-06-01

    In this paper, we report simultaneous detection of fluorescence and turbidity using a multiwavelength photosensor. The multiwavelength photosensor is fabricated in a 5 µm 1-poly 1-metal p-well complementary metal oxide semiconductor (CMOS) technology. First, to confirm the basic characteristics of the multiwavelength photosensor, the linearity of irradiated intensity and photocurrent, fluorescence detection capability, and turbidity detection capability were separately observed. Then, in the fluorescence detection measurement using a fluorescent dye, a detection limit of DNA concentration of 49.8 nM was determined. Then, the turbidity detection performance was compared with that of a Si photodiode. Finally, the sensor was used for real-time monitoring of DNA amplification using the loop-mediated isothermal amplification (LAMP) method. Owing to its multiwavelength detection, simultaneous changes in fluorescence and turbidity were successfully observed using a single sensor.

  19. Phosphorus, and nitrogen co-doped carbon dots as a fluorescent probe for real-time measurement of reactive oxygen and nitrogen species inside macrophages.

    PubMed

    Gong, Yunqian; Yu, Bin; Yang, Wen; Zhang, Xiaoling

    2016-05-15

    Phosphorus and nitrogen doped carbon dots (PN-CDs) were conveniently prepared by carbonization of adenosine-5'-triphosphate using a hydrothermal treatment. The PN-CDs with P/C atomic ratio of ca. 9.2/100 emit blue luminescence with high quantum yields of up to 23.5%. The PN-CDs were used as a novel sensing platform for live cell imaging of reactive oxygen species (ROS) and reactive nitrogen species (RNS), including ClO(-), ONOO(-), and NO in macrophages. The nanosensor design is based on our new finding that the strong fluorescence of the PN-CDs can be sensitively and selectively quenched by ROS and RNS both in vitro and in vivo. These results reveal that the PN-CDs can serve as a sensitive sensor for rapid imaging of ROS and RNS signaling with high selectivity and contrast. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Real time micro-fiberoptic monitoring of endogenous fluorescence in the rat conceptus during hypoxia.

    PubMed

    Thorsrud, B A; Harris, C

    1993-10-01

    A micro-fiberoptic methodology has been developed for non-invasive, real time measurement of endogenous pyridine nucleotide fluorescence from the surface of the visceral yolk sac (VYS) in intact, viable rat conceptuses. Gestational day (GD) 10-12 conceptuses are maintained in a customized perifusion system, which allows for control of oxygenation, as well as the continuous measurement of pH and oxygen concentration in the effluent perifusate. Miniaturized light guides were constructed by drawing 250 microns ESKA acrylic optical fibers through a stainless steel sheath with a high strength epoxy polymer. A single fiber supplied the excitation signal from a mercury arc lamp at a wavelength of 366 nm. The emission signal was returned via three additional fibers, electronically amplified, processed, and recorded, using a dual channel lamp-compensated fluorometer, optimized for detection of reduced pyridine nucleotides at 455 nm. Endogenous fluorescence in the conceptus was monitored by placing the polished tip of the sensor directly on the surface of the VYS. Oxygen-equilibrated conceptuses, exposed to 100% nitrogen, produced a reproducible biphasic surface fluorescence peak, which returned to baseline levels upon reoxygenation of the perifusate. This biphasic response consisted of an initial rapid rise in fluorescence (phase I), followed by an attenuated rate in fluorescence signal increase (phase II). The hypoxia produced age-dependent rates of fluorescence change during phase I, while phase II remained relatively unchanged throughout GD 10-12. These results demonstrate the ability to monitor endogenous fluorescence, non-invasively and in real time, during the period of organogenesis in the intact rat conceptus and will provide valuable information in studies of embryonic metabolism and response to chemical embryotoxicants.

  1. Real-time measurement of mental workload: A feasibility study

    NASA Technical Reports Server (NTRS)

    Kramer, Arthur; Humphrey, Darryl; Sirevaag, Erik; Mecklinger, Axel

    1990-01-01

    The primary goal of the study was to explore the utility of event-related brain potentials (ERP) as real-time measures of workload. To this end, subjects performed two different tasks both separately and together. One task required that subjects monitor a bank of constantly changing gauges and detect critical deviations. Difficulty was varied by changing the predictability of the gauges. The second task was mental arithmetic. Difficulty was varied by requiring subjects to perform operations on either two or three columns of numbers. Two conditions that could easily be distinguished on the basis of performance measures were selected for the real-time evaluation of ERPs. A bootstrapping approach was adopted in which one thousand samples of n trials (n = 1, 3, 5 ...65) were classified using several measures of P300 and Slow Wave amplitude. Classification accuracies of 85 percent were achieved with 25 trials. Results are discussed in terms of potential enhancements for real-time recording.

  2. Real-time Fluorescence Image-Guided Oncologic Surgery

    PubMed Central

    Mondal, Suman B.; Gao, Shengkui; Zhu, Nan; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

    2014-01-01

    Medical imaging plays a critical role in cancer diagnosis and planning. Many of these patients rely on surgical intervention for curative outcomes. This requires a careful identification of the primary and microscopic tumors, and the complete removal of cancer. Although there have been efforts to adapt traditional imaging modalities for intraoperative image guidance, they suffer from several constraints such as large hardware footprint, high operation cost, and disruption of the surgical workflow. Because of the ease of image acquisition, relatively low cost devices and intuitive operation, optical imaging methods have received tremendous interests for use in real-time image-guided surgery. To improve imaging depth under low interference by tissue autofluorescence, many of these applications utilize light in the near-infra red (NIR) wavelengths, which is invisible to human eyes. With the availability of a wide selection of tumor-avid contrast agents, advancements in imaging sensors, electronic and optical designs, surgeons are able to combine different attributes of NIR optical imaging techniques to improve treatment outcomes. The emergence of diverse commercial and experimental image guidance systems, which are in various stages of clinical translation, attests to the potential high impact of intraoperative optical imaging methods to improve speed of oncologic surgery with high accuracy and minimal margin positivity. PMID:25287689

  3. Real-time structured light intraoral 3D measurement pipeline

    NASA Astrophysics Data System (ADS)

    Gheorghe, Radu; Tchouprakov, Andrei; Sokolov, Roman

    2013-02-01

    Computer aided design and manufacturing (CAD/CAM) is increasingly becoming a standard feature and service provided to patients in dentist offices and denture manufacturing laboratories. Although the quality of the tools and data has slowly improved in the last years, due to various surface measurement challenges, practical, accurate, invivo, real-time 3D high quality data acquisition and processing still needs improving. Advances in GPU computational power have allowed for achieving near real-time 3D intraoral in-vivo scanning of patient's teeth. We explore in this paper, from a real-time perspective, a hardware-software-GPU solution that addresses all the requirements mentioned before. Moreover we exemplify and quantify the hard and soft deadlines required by such a system and illustrate how they are supported in our implementation.

  4. Real-time measurements of jet aircraft engine exhaust.

    PubMed

    Rogers, Fred; Arnott, Pat; Zielinska, Barbara; Sagebiel, John; Kelly, Kerry E; Wagner, David; Lighty, JoAnn S; Sarofim, Adel F

    2005-05-01

    Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.

  5. Real-time quantitative fluorescence imaging using a single snapshot optical properties technique for neurosurgical guidance

    NASA Astrophysics Data System (ADS)

    Valdes, Pablo A.; Angelo, Joseph; Gioux, Sylvain

    2015-03-01

    Fluorescence imaging has shown promise as an adjunct to improve the extent of resection in neurosurgery and oncologic surgery. Nevertheless, current fluorescence imaging techniques do not account for the heterogeneous attenuation effects of tissue optical properties. In this work, we present a novel imaging system that performs real time quantitative fluorescence imaging using Single Snapshot Optical Properties (SSOP) imaging. We developed the technique and performed initial phantom studies to validate the quantitative capabilities of the system for intraoperative feasibility. Overall, this work introduces a novel real-time quantitative fluorescence imaging method capable of being used intraoperatively for neurosurgical guidance.

  6. Inexpensive system for real-time 3-dimensional video-oculography using a fluorescent marker array

    PubMed Central

    Migliaccio, Americo A.; MacDougall, Hamish G.; Minor, Lloyd B.; Della Santina, Charles C.

    2009-01-01

    We describe a novel, inexpensive method for real-time measurement of binocular three-dimensional eye position. The method employs consumer-grade digital video cameras (“webcams”) to track an array of three fluorescent non-collinear markers affixed to each eye. The instantaneous position of the marker array relative to a reference position is used to construct a rotation matrix describing the eye rotation. The mathematical computation used to determine the rotation matrix is conceptually simpler and computationally more efficient than methods previously described, allowing generation of binocular three-dimensional eye position in real-time during image acquisition. The fluorescent marker is illuminated using a UV-A light source. The light source and reflective artifacts are filtered out to improve the signal to noise ratio. In addition, we present a method to align the camera with the center of eye rotation. When tested in vitro, the video-oculography (VOG) method had a <2.9% positional error (in each component of 3D eye position) for eye positions within 20° of center. We directly compared this method of VOG to the search coil technique by measuring three-dimensional eye position simultaneously using search coils and VOG in a chinchilla (C. laniger). The in vivo positional difference between the two methods was <3.1% for each component of 3D eye position. PMID:15814146

  7. Current Trends in Ligand Binding Real-Time Measurement Technologies.

    PubMed

    Fraser, Stephanie; Shih, Judy Y; Ware, Mark; O'Connor, Edward; Cameron, Mark J; Schwickart, Martin; Zhao, Xuemei; Regnstrom, Karin

    2017-03-20

    Numerous advances in ligand binding assay (LBA) real-time measurement technologies have been made within the last several years, ranging from the development of novel platforms to drive technology expansion to the adaptation of existing platforms to optimize performance and throughput. In this review, we have chosen to focus on technologies that provide increased value to two distinct segments of the LBA community. First, experimentally, by measuring real-time binding events, these technologies provide data that can be used to interrogate receptor/ligand binding interactions. While overall the platforms are not new, they have made significant advances in throughput, multiplexing, and/or sensitivity. Second, clinically, these point-of-care (POC) technologies provide instantaneous information which facilitates rapid treatment decisions.

  8. Real-time phosphate sensing in living cells using fluorescence lifetime imaging microscopy (FLIM).

    PubMed

    Paredes, Jose M; Giron, Maria D; Ruedas-Rama, Maria J; Orte, Angel; Crovetto, Luis; Talavera, Eva M; Salto, Rafael; Alvarez-Pez, Jose M

    2013-07-11

    Phosphate ions play important roles in signal transduction and energy storage in biological systems. However, robust chemical sensors capable of real-time quantification of phosphate anions in live cells have not been developed. The fluorescein derivative dye 9-[1-(2-methyl-4-methoxyphenyl)]-6-hydroxy-3H-xanthen-3-one (2-Me-4-OMe TG) exhibits the characteristic excited-state proton-transfer (ESPT) reaction of xanthenic derivatives at approximately physiological pH resulting in the dependence of the dye's nanosecond fluorescence decay time on the phosphate buffer concentration. This allows the 2-Me-4-OMe TG dye to be used with fluorescence lifetime imaging microscopy (FLIM) as a real-time phosphate intracellular sensor in cultured cells. This methodology has allowed the time course of cellular differentiation of MC3T3-E1 murine preosteoblast cells to be measured on the basis of the decrease in the decay time of 2-Me-4-OMe TG. These changes were consistent with increased alkaline phosphatase activity in the extracellular medium as a marker of the differentiation process.

  9. Real-time water and wastewater quality monitoring using LED-based fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Bridgeman, John; Zakharova, Yulia

    2016-04-01

    In recent years there have been a number of attempts to design and introduce into water management tools that are capable of measuring organic and microbial matter in real time and in situ. This is important, as the delivery of safe water to customers, and the discharge of good quality effluent to rivers are primary concerns to water undertakers. A novel, LED-based portable fluorimeter 'Duo Fluor' has been designed and constructed at the University of Birmingham to monitor the quality of (waste)water continuously and in real time, and its performance has been assessed in a range of environments. To be of use across a range of environments, special attention must be paid to two crucially important characteristics of such instruments, i.e. their sensitivity and robustness. Thus, the objectives of this study were: 1. To compare the performance (in terms of their sensitivity and robustness) of the Duo Fluor and two other commercial fluorescence devices in laboratory conditions. 2. To assess the performance of the Duo Fluor in situ, in real time at a 450,000PE WwTW. Initially, the impact of quinine sulphate (QS), a highly fluorescent alkaloid with high quantum fluorescence yield, on peak T fluorescence in environmental waters was examined for the Duo Fluor and two commercially available, chamber-based fluorimeters, (F1) and (F2). The instruments' responses to three scenarios were assessed: 1. Deionised water (DW) spiked with QS (from 0.05 to 0.4 mg/L); 2. Environmental water (pond water, PW) spiked with QS (from 0.05 to 0.4 mg/L); 3. Different water samples from various environmental source. The results show that the facility to amend gain settings and the suitable choice of gain are crucial to obtaining reliable data on both peaks T and C in a wide range of water types. The Duo Fluor offers both of these advantages whilst commercially available instruments currently do not. The Duo Fluor was subsequently fixed at the final effluent (FE) discharge point of a WwTW and FE

  10. Real-time fluorescence lifetime actuation for cell sorting using a CMOS SPAD silicon photomultiplier.

    PubMed

    Rocca, Francescopaolo Mattioli Della; Nedbal, Jakub; Tyndall, David; Krstajić, Nikola; Li, David Day-Uei; Ameer-Beg, Simon M; Henderson, Robert K

    2016-02-15

    Time-correlated single photon counting (TCSPC) is a fundamental fluorescence lifetime measurement technique offering high signal to noise ratio (SNR). However, its requirement for complex software algorithms for histogram processing restricts throughput in flow cytometers and prevents on-the-fly sorting of cells. We present a single-point digital silicon photomultiplier (SiPM) detector accomplishing real-time fluorescence lifetime-activated actuation targeting cell sorting applications in flow cytometry. The sensor also achieves burst-integrated fluorescence lifetime (BIFL) detection by TCSPC. The SiPM is a single-chip complementary metal-oxide-semiconductor (CMOS) sensor employing a 32×32 single-photon avalanche diode (SPAD) array and eight pairs of time-interleaved time to digital converters (TI-TDCs) with a 50 ps minimum timing resolution. The sensor's pile-up resistant embedded center of mass method (CMM) processor accomplishes low-latency measurement and thresholding of fluorescence lifetime. A digital control signal is generated with a 16.6 μs latency for cell sorter actuation allowing a maximum cell throughput of 60,000 cells per second and an error rate of 0.6%.

  11. Whole-body, real-time preclinical imaging of quantum dot fluorescence with time-gated detection.

    PubMed

    May, Andrzej; Bhaumik, Srabani; Gambhir, Sanjiv S; Zhan, Chun; Yazdanfar, Siavash

    2009-01-01

    We describe a wide-field preclinical imaging system optimized for time-gated detection of quantum dot fluorescence emission. As compared to continuous wave measurements, image contrast was substantially improved by suppression of short-lifetime background autofluorescence. Real-time (8 frames/s) biological imaging of subcutaneous quantum dot injections is demonstrated simultaneously in multiple living mice.

  12. Whole-body, real-time preclinical imaging of quantum dot fluorescence with time-gated detection

    NASA Astrophysics Data System (ADS)

    May, Andrzej; Bhaumik, Srabani; Gambhir, Sanjiv S.; Zhan, Chun; Yazdanfar, Siavash

    2009-11-01

    We describe a wide-field preclinical imaging system optimized for time-gated detection of quantum dot fluorescence emission. As compared to continuous wave measurements, image contrast was substantially improved by suppression of short-lifetime background autofluorescence. Real-time (8 frames/s) biological imaging of subcutaneous quantum dot injections is demonstrated simultaneously in multiple living mice.

  13. Real time monitoring of superoxide dynamics in vivo through fluorescent proteins using a sensitive fiber probe

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Chung; Ken, Chuian-Fu; Hsu, Che-Wei; Liu, Ya-Ging

    2014-03-01

    Superoxide anion is the primary oxygen free radical generated in mitochondria that causes intracellular oxidative stress. The lack of a method to directly monitor superoxide concentration in vivo in real time has severely hindered our understanding on its pathophysiology. We made transgenic zebrafish to specifically express fluorescent proteins, which are recently developed as reversible superoxide-specific indicators, in the liver. A fiber-optic fluorescent probe was used to noninvasively monitor superoxide generation in the liver in real time. The fish were placed in microfluidic channels for manipulation and reagents administration. Several superoxide-inducing and scavenging reagents were administrated onto the fish to investigate their effects on superoxide anion balancing. The biochemical dynamics of superoxide due to the application reagents were revealed in the transient behaviors of fluorescence time courses. With the ability to monitor superoxide dynamics in vivo in real time, this method can be used as an in vivo pharmaceutical screening platform.

  14. Continuous real-time measurement of aqueous cyanide

    DOEpatents

    Rosentreter, Jeffrey J.; Gering, Kevin L.

    2007-03-06

    This invention provides a method and system capable of the continuous, real-time measurement of low concentrations of aqueous free cyanide (CN) using an on-line, flow through system. The system is based on the selective reactivity of cyanide anions and the characteristically nonreactive nature of metallic gold films, wherein this selective reactivity is exploited as an indirect measurement for aqueous cyanide. In the present invention the dissolution of gold, due to the solubilization reaction with the analyte cyanide anion, is monitored using a piezoelectric microbalance contained within a flow cell.

  15. Real-time tracking imaging measurement of low stretched trajectory

    NASA Astrophysics Data System (ADS)

    Wu, Haiying; Zhang, Sanxi; Liu, Pengzu; Zhang, Weiguang; Wang, Weiqiang

    2014-02-01

    The high speed tracing imaging technique based on a scanning reflector, can realize a real-time tracking imaging measurement of the live scene. It can compensate field of view of the fixed high speed camera and scanning velocity of photoelectric theodolites. In this work, a synchronous tracking system realized by a rotating mirror is introduced. The imaging performance is analyzed in detail. The scheme to gain flight characteristics of targets is presented. A certificated test is performed and its results confirmed the feasibility of this system.

  16. Nondestructive and Real-time Measurement of Moisture in Plant

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi; Kawase, Kodo; Mizuno, Maya; Yamashita, Masatsugu; Otani, Chiko

    We constructed a THz transillumination system for water content monitoring, and we succeeded in measuring the moisture level in plants. Our measurement system uses a widely tunable coherent THz parametric oscillator source. As target we chose for this experiment a leaf of Japanese basil. The time variation of the water content in the leaf was monitored in two situations: a leaf freshly cut which is left to dry out, and the leaf of a water stressed plant. We found by real-time measurements that the water content of a cut leaf does not decrease uniformly in time. Also, the response to water stress is delayed by about 5-10 minutes. Furthermore, we demonstrated a moisture measurement using a transillumination THz imaging system. As target we chose for this experiment a leaf of Hedera helix held between two thin plastic sheets. The change of the moisture distribution is clearly visible. These results show that the method described here can be applied to nondestructive and real-time monitoring of water content in plants.

  17. Real-Time performance measurements of EPICS IOCcore.

    SciTech Connect

    Xu, S.; Kraimer, M. R.; Accelerator Systems Division

    2005-01-01

    As the Experimental Physics and Industrial Control System (EPICS) is used in an increasing number of accelerator control systems, EPICS IOCcore is ported to a wider variety of OS platforms and thus the performance of EPICS IOCcore on different hardware and software platforms becomes more important. This paper provides real-time performance measurements of EPICS IOCcore on a VME hardware platform and on three different OS platforms: vxWorks, RTEMS, and Linux. EPICS Input/Output Controller core (IOCcore) software has been ported to several different operating systems (OSs) and many hardware platforms. This paper compares the EPICS IOCcore runtime performance on one hardware platform (MVME2100 PowerPC) and three popular Operating Systems: vxWorks, RTEMS, and Linux. For Linux the following versions were tested: Linux 2.4.2 hard hat 2.0, standard Linux 2.4.30, and Linux 2.6.13. For Linux 2.6.13, the kernel was built both preemptive and non-preemptive. Three real-time parameters are measured: interrupt, context switch, and total response latency. On Linux, more detailed interrupt latencies are measured: interrupt top half to bottom half, and interrupt bottom half to user space interrupt service routine. To implement the tests, several software components were developed. In order to port to other operating systems or hardware platforms only, one component has to be implemented.

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

    NASA Astrophysics Data System (ADS)

    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

  19. Real-time spectrogram measurements of fibre Raman solitons

    NASA Astrophysics Data System (ADS)

    Ogawa, K.; Pelusi, M. D.

    2002-06-01

    Raman solitons propagated in the anomalous-dispersion regime in a 5-m standard-dispersion single-mode optical fibre are studied by real-time acquisition of traces of two-photon-absorption frequency-resolved optical gating at wavelengths around 1500 nm. Rapid wavelength scanning based on a counter-rotating mirror is invented to realise real-time spectrogram measurements under background-free lock-in detection using a single-channel photodiode. The measurement period in this method is 1.8 s for a spectrogram of 128×128 pixels. Intuitive spectrograms of a fibre Raman soliton and a pedestal are acquired at various peak powers of an incident optical pulse to analyse walk-off of the fundamental-mode Raman soliton. The soliton walk-off is limited by 2nd-order chromatic dispersion in the fibre. A dispersion parameter of 9.3 ps/nm/km is obtained from the wavelength dependence of the soliton walk-off.

  20. Real-time spectrogram measurements of fibre Raman solitons

    NASA Astrophysics Data System (ADS)

    Ogawa, K.; Pelusi, M. D.

    Raman solitons propagated in the anomalous-dispersion regime in a 5-m standard-dispersion single-mode optical fibre are studied by real-time acquisition of traces of two-photon-absorption frequency-resolved optical gating at wavelengths around 1500 nm. Rapid wavelength scanning based on a counter-rotating mirror is invented to realise real-time spectrogram measurements under background-free lock-in detection using a single-channel photodiode. The measurement period in this method is 1.8 s for a spectrogram of 128×128 pixels. Intuitive spectrograms of a fibre Raman soliton and a pedestal are acquired at various peak powers of an incident optical pulse to analyse walk-off of the fundamental-mode Raman soliton. The soliton walk-off is limited by 2nd-order chromatic dispersion in the fibre. A dispersion parameter of 9.3 ps/nm/km is obtained from the wavelength dependence of the soliton walk-off.

  1. Real-time method for bronchoscope motion measurement and tracking

    NASA Astrophysics Data System (ADS)

    Cornish, Duane C.; Higgins, William E.

    2011-03-01

    Bronchoscopy-guidance systems have been shown to improve the success rate of bronchoscopic procedures. A key technical cornerstone of bronchoscopy-guidance systems is the synchronization between the virtual world, derived from a patient's three-dimensional (3D) multidetector computed-tomography (MDCT) scan, and the real world, derived from the bronchoscope video during a live procedure. Two main approaches for synchronizing these worlds exist: electromagnetic navigation bronchoscopy (ENB) and image-based bronchoscopy. ENB systems require considerable extra hardware, and both approaches have drawbacks that hinder continuous robust guidance. In addition, they both require an attending technician to be present. We propose a technician-free strategy that enables real-time guidance of bronchoscopy. The approach uses measurements of the bronchoscope's movement to predict its position in 3D virtual space. To achieve this, a bronchoscope model, defining the device's shape in the airway tree to a given point p, provides an insertion depth to p. In real time, our strategy compares an observed bronchoscope insertion depth and roll angle, measured by an optical sensor, to precalculated insertion depths along a predefined route in the virtual airway tree. This leads to a prediction of the bronchoscope's location and orientation. To test the method, experiments involving a PVC-pipe phantom and a human airway-tree phantom verified the bronchoscope models and the entire method, respectively. The method has considerable potential for improving guidance robustness and simplicity over other bronchoscopy-guidance systems.

  2. Real time monitoring of urban surface water quality using a submersible, tryptophan-like fluorescence sensor

    NASA Astrophysics Data System (ADS)

    Khamis, Kieran; Bradley, Chris; Hannah, David; Stevens, Rob

    2014-05-01

    Due to the recent development of field-deployable optical sensor technology, continuous quantification and characterization of surface water dissolved organic matter (DOM) is possible now. Tryptophan-like (T1) fluorescence has the potential to be a particularly useful indicator of human influence on water quality as T1 peaks are associated with the input of labial organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time recording of T1 fluorescence could be particular useful for monitoring waste water infrastructure, treatment efficiency and the identification of contamination events at higher temporal resolution than available hitherto. However, an understanding of sensor measurement repeatability/transferability and interaction with environmental parameters (e.g. turbidity) is required. Here, to address this practical knowledge gap, we present results from a rigorous test of a commercially available submersible tryptophan fluorometer (λex 285, λem 350). Sensor performance was first examined in the laboratory by incrementally increasing turbidity under controlled conditions. Further to this the sensor was integrated into a multi-parameter sonde and field tests were undertaken involving: (i) a spatial sampling campaign across a range of surface water sites in the West Midlands, UK; and (ii) collection of high resolution (sub-hourly) samples from an urban stream (Bournbrook, Birmingham, U.K). To determine the ability of the sensor to capture spatiotemporal dynamics of urban waters DOM was characterized for each site or discrete time step using Excitation Emission Matrix spectroscopy and PARAFAC. In both field and laboratory settings fluorescence intensity was attenuated at high turbidity due to suspended particles increasing absorption and light scattering. For the spatial survey, instrument readings were compared to those obtained by a laboratory grade fluorometer (Varian Cary Eclipse) and a strong, linear relationship was apparent

  3. Amplifying the fluorescence of bilirubin enables the real-time detection of heme oxygenase activity.

    PubMed

    Klemz, Roman; Mashreghi, Mir-Farzin; Spies, Claudia; Volk, Hans-Dieter; Kotsch, Katja

    2009-01-15

    Heme oxygenases (HO) are the rate-limiting enzymes in the degradation of heme to equimolar amounts of antioxidant bile pigments, the signaling molecule carbon monoxide, and ferric iron. The inducible form HO-1 confers protection on cells and tissues that mediates beneficial effects in many diseases. Consequently, measurement of the enzymatic activity is vital in the investigation of the regulatory role of HO. Here we report that the fluorescence characteristics of bilirubin in complex with serum albumin can be used for the real-time detection of HO activity in enzymatic kinetics measurements. We characterized the enzymatic activity of a truncated human HO-1 and measured the HO activity for various cell types and organs, in either the basal naive or the HO-1-induced state. The bilirubin-dependent increase in fluorescence over time monitored by this assay facilitates a very fast, sensitive, and reliable measurement of HO activity. Our approach offers the basis for a highly sensitive high-throughput screening, which provides, inter alia, the opportunity to discover new therapeutic HO-1-inducing agents.

  4. [Application of fluorescent real-time reverse transcriptase-polymerase chain reaction in detecting influenza viruses].

    PubMed

    Cheng, Xiao-wen; Zhou, Li; Zhao, Jin; Fang, Shi-song; Yu, Lei; Ye, Bao-ying; He, Jian-fan; Lu, Xing; Zhang, Zai-qing; Yang, Hong

    2004-09-01

    To apply fluorescent real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in detecting influenza viruses. A total of 207 oral swab samples were obtained in 16 collections from SARS patients and suspected influenza outbreak cases. They were subjected to influenza virus detection by fluorescent real-time RT-PCR, MDCK cell culture, and hemagglutinin inhibition assay. Out of 207 samples, 79 (38.16%) were positive for influenza viruses when tested by fluorescent real-time PCR, and 62 (29.95%) positive when tested by MDCK cell culture. There was a statistically significant difference between them (chi square=8.64, P less than 0.005). From 104 cases in 9 collections dual serum samples were obtainable. When tested with hemagglutinin inhibition assay, 64 cases (61.54%) showed a 4-fold increase against H3N2 antigen. This study showed that fluorescent real-time PCR is a reliable, sensitive, and fast method for detecting influenza viruses.

  5. DEVELOPMENT OF A REAL-TIME FLUORESCENCE RESONANCE ENERGY TRANSFER (FRET) PCR TO DETECT ARCOBACTER SPECIES

    USDA-ARS?s Scientific Manuscript database

    A real-time PCR targeting the gyrase A subunit gene outside the quinolone resistance-determining region has been developed to detect Arcobacter species. The species identification was made by probe hybridization and melting curve analysis, using the Fluorescence Resonance Energy Transfer technology...

  6. DEVELOPMENT OF A REAL-TIME FLUORESCENCE RESONANCE ENERGY TRANSFER PCR TO DETECT ARCOBACTER SPECIES

    USDA-ARS?s Scientific Manuscript database

    A real-time PCR targeting the gyrase A subunit gene outside the quinolone resistance-determining region has been developed to detect Arcobacter species. The species identification was made by probe hybridization and melting curve analysis, using Fluorescence Resonance Energy Transfer technology. D...

  7. Improved process control through real-time measurement of mineral content

    SciTech Connect

    Turler, Daniel; Karaca, Murat; Davis, William B.; Giauque, Robert D.; Hopkins, Deborah

    2001-11-02

    In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

  8. Nanofluidic Fluorescence Microscopy (NFM) for real-time monitoring of protein binding kinetics and affinity studies.

    PubMed

    Teerapanich, Pattamon; Pugnière, Martine; Henriquet, Corinne; Lin, Yii-Lih; Chou, Chia-Fu; Leïchlé, Thierry

    2017-02-15

    Kinetic monitoring of protein interactions offers insights to their corresponding functions in cellular processes. Surface plasmon resonance (SPR) is the current standard tool used for label-free kinetic assays; however, costly and sophisticated setups are required, decreasing its accessibility to research laboratories. We present a cost-effective nanofluidic-based immunosensor for low-noise real-time kinetic measurement of fluorescent-labeled protein binding. With the combination of fluorescence microscopy and reversed buffer flow operation, association and dissociation kinetics can be accessed in one single experiment without extra buffer loading step, which results in a simplified operation and reduced time of analysis compared to typical microfluidic immunoassays. Kinetic constants of two representative protein-ligand binding pairs (streptavidin/biotin; IgG/anti-IgG) were quantified. The good agreement of extracted rate constants with literature values and analogous SPR measurements indicates that this approach is applicable to study protein interactions of medium- and high-affinities with a limit of detection down to 1 pM, regardless of the analyte size.

  9. Detection of shrimp-derived components in food by real-time fluorescent PCR.

    PubMed

    Cao, Jijuan; Yu, Bing; Ma, Lidan; Zheng, Qiuyue; Zhao, Xin; Xu, Junyi

    2011-10-01

    Crustaceans such as shrimp and crabs and their products are important allergens in food, and allergic reactions due to the consumption of shrimp and crabs are frequently reported. However, the chemical properties of shrimp-derived allergens, except for Pen a I, are still unclear. Therefore, it is important to establish a more sensitive and specific method for detecting the composition of foods containing shrimp. In the present study, we developed a real-time fluorescent PCR to identify the specific shrimp-derived components in food. The primers and TaqMan probes for real-time fluorescent PCR were designed based on 16S rRNA genes through comparing a large number of nucleic acid sequences from different species of shrimp that have been published by the National Center for Biotechnology Information. In total, 56 kinds of samples, including different kinds of shrimp, crab, fish, shellfish, and octopus, were subjected to detection by real-time PCR. The results indicated that real-time fluorescent PCR could successfully identify the shrimp-derived components. In order to explore the effect of food processing on detection sensitivity, fish powder containing shrimp powder was treated by heating at 133°C for 30 min. The limit of detection of shrimp-derived components in fish powder was 0.05% (wt/wt).

  10. Real-time diamagnetic flux measurements on ASDEX Upgrade.

    PubMed

    Giannone, L; Geiger, B; Bilato, R; Maraschek, M; Odstrčil, T; Fischer, R; Fuchs, J C; McCarthy, P J; Mertens, V; Schuhbeck, K H

    2016-05-01

    Real-time diamagnetic flux measurements are now available on ASDEX Upgrade. In contrast to the majority of diamagnetic flux measurements on other tokamaks, no analog summation of signals is necessary for measuring the change in toroidal flux or for removing contributions arising from unwanted coupling to the plasma and poloidal field coil currents. To achieve the highest possible sensitivity, the diamagnetic measurement and compensation coil integrators are triggered shortly before plasma initiation when the toroidal field coil current is close to its maximum. In this way, the integration time can be chosen to measure only the small changes in flux due to the presence of plasma. Two identical plasma discharges with positive and negative magnetic field have shown that the alignment error with respect to the plasma current is negligible. The measured diamagnetic flux is compared to that predicted by TRANSP simulations. The poloidal beta inferred from the diamagnetic flux measurement is compared to the values calculated from magnetic equilibrium reconstruction codes. The diamagnetic flux measurement and TRANSP simulation can be used together to estimate the coupled power in discharges with dominant ion cyclotron resonance heating.

  11. Real-time ratiometric fluorescent assay for alkaline phosphatase activity with stimulus responsive infinite coordination polymer nanoparticles.

    PubMed

    Deng, Jingjing; Yu, Ping; Wang, Yuexiang; Mao, Lanqun

    2015-03-03

    This study demonstrates a novel ratiometric fluorescent method for real-time alkaline phosphatase (ALP) activity assay with stimulus responsive infinite coordination polymer (ICP) nanoparticles as the probe. The ICP nanoparticles used in this study are composed of two components; one is the supramolecular ICP network formed with guanine monophosphate (GMP) as the ligand and Tb(3+) as the central metal ion, and the other is a fluorescent dye, i.e., 7-amino-4-methyl coumarin (coumarin) encapsulated into the ICP network. Upon being excited at 315 nm, the ICP network itself emits green fluorescence at 552 nm. Coumarin dye encapsulated in the ICP network emits weak fluorescence at 450 nm upon excitation at the same wavelength (315 nm), and this fluorescence emission becomes strong when the encapsulated dye is released from the network into the solution phase. Hence, we develop a ratiometric fluorescent assay based on the ALP-induced destruction of the supramolecular ICP network and the release of coumarin. This mechanism can be used for real-time ratiometric fluorescent monitoring of ALP activity by continuously measuring the ratio of fluorescent intensity at the wavelength of 552 nm (F552) to that at 450 nm (F450) (F552/F450) in the time-dependent fluorescent spectra of the coumarin@Tb-GMP suspension containing ALP with different activities. Under the experimental conditions employed here, the F552/F450 value is linear with the ALP activity within a range from 0.025 U/mL to 0.2 U/mL. The detection limit is down to 0.010 U/mL (S/N = 3). Moreover, the assay developed here is employed for ALP inhibitor evaluation. This study offers a simple yet sensitive method for real-time ALP activity assay.

  12. Designing Information Measures for Real-time Lightcurve Classification

    NASA Astrophysics Data System (ADS)

    Jones, David Edward; Chen, Yang; Meng, Xiao-Li; Siemiginowska, Aneta; Kashyap, Vinay

    2016-01-01

    Since telescope time is limited, real-time lightcurve classification involves carefully selecting future time points at which sources must be observed in order to maximize the information that will be gained for classification. We propose a framework for constructing measures of information for testing/classification/model-selection and demonstrate their use in experimental design. Degroot (1962) developed a general framework for constructing Bayesian measures of the expected information that an experiment will provide for estimation, and our framework analogously constructs measures of information for hypothesis testing. Such test information measures are most useful for model selection and classification problems. Indeed, our framework suggests a probability based measure of test information, which in decision problems has more appealing properties than variance based measures. In the case of lightcurve classification, we adapt our designs to penalize long waits until the next observation time. Lastly, we consider ways to address other aspects of the problem, such as uncertainty estimation arising due to contamination from nearby contaminating sources or background diffuse emission. We acknowledge support from Smithsonian Competitive Grants Fund 40488100HH0043 and NSF grant DMS 1208791.

  13. Real-time maximum a-posteriori image reconstruction for fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Jabbar, Anwar A.; Dilipkumar, Shilpa; C K, Rasmi; Rajan, K.; Mondal, Partha P.

    2015-08-01

    Rapid reconstruction of multidimensional image is crucial for enabling real-time 3D fluorescence imaging. This becomes a key factor for imaging rapidly occurring events in the cellular environment. To facilitate real-time imaging, we have developed a graphics processing unit (GPU) based real-time maximum a-posteriori (MAP) image reconstruction system. The parallel processing capability of GPU device that consists of a large number of tiny processing cores and the adaptability of image reconstruction algorithm to parallel processing (that employ multiple independent computing modules called threads) results in high temporal resolution. Moreover, the proposed quadratic potential based MAP algorithm effectively deconvolves the images as well as suppresses the noise. The multi-node multi-threaded GPU and the Compute Unified Device Architecture (CUDA) efficiently execute the iterative image reconstruction algorithm that is ≈200-fold faster (for large dataset) when compared to existing CPU based systems.

  14. Miniature real time PCR on chip with multi-channel fiber optical fluorescence detection module.

    PubMed

    Xiang, Q; Xu, B; Li, D

    2007-08-01

    This paper presents the design and implementation of a miniature real time PCR system consisting of a disposable reactor chip, a miniature thermal cycler, and a multi-channel fiber optical fluorescence excitation/detection module. The disposable PCR chip is fabricated by using soft photolithography by PDMS (Polydimethylsiloxane) and glass. The miniature thermal cycler has a thin film heater for heating and a fan for rapid cooling. The fiber optical detection module consists of laser, filter cube, photo-detector and 1x4 fiber optical switch. It is capable of four-well real time PCR analysis. Real-time PCR detection of E. coli stx1 has been demonstrated successfully with this system.

  15. Conjugated polyelectrolyte-based real-time fluorescence assay for alkaline phosphatase with pyrophosphate as substrate.

    PubMed

    Liu, Yan; Schanze, Kirk S

    2008-11-15

    The fluorescence of the anionic, carboxylate-substituted poly(phenylene ethynylene) polymer PPECO2 is quenched very efficiently via the addition of 1 equiv of Cu(2+). Addition of pyrophosphate (PPi) into the weakly fluorescent solution of PPECO2 and Cu(2+) induces recovery of the polymer's fluorescence; the recovery occurs because PPi complexes with Cu(2+), effectively sequestering the ion so it cannot bind to the carboxylate groups of the polymer. A calibration curve was developed that relates the extent of fluorescence recovery to [PPi], making the PPECO2-Cu(2+) system a sensitive and selective turn-on sensor for PPi. Using the PPECO2-Cu(2+) system as the signal transducer, a real-time fluorescence turn-off assay for the enzyme alkaline phosphatase (ALP) using PPi as the substrate is developed. The assay operates with [PPi] in the micromolar range, and it offers a straightforward and rapid detection of ALP activity with the enzyme present in the nanomolar concentration range, operating either in an end point or real-time format. Kinetic and product inhibition parameters are derived by converting time-dependent fluorescence intensity into PPi (substrate) concentration, thus allowing calculation of the initial reaction rates (v(o)). Weak, nonspecific fluorescence responses are observed concomitant to addition of other proteins to the assay solution; however, the signal response to ALP is demonstrated to arise from the ALP catalyzed hydrolysis of PPi to phosphate (Pi).

  16. Excimer laser fragmentation fluorescence spectroscopy for real-time monitoring of combustion generated pollutants

    NASA Astrophysics Data System (ADS)

    Damm, Christopher John

    Toxic pollutant emissions from combustion pose a hazard to public and environmental health. Better diagnostic techniques would benefit emissions monitoring programs and aid research aimed at understanding toxic pollutant formation and behavior. Excimer Laser Fragmentation Fluorescence Spectroscopy (ELFFS) provides sensitive, real-time, in situ measurements of several important combustion related pollutants. This thesis demonstrates the capabilities of ELFFS for detecting amines in combustion exhausts and carbonaceous particulate matter from engines. ELFFS photofragments target species using a 193 nm excimer laser to form fluorescent signature species. The NH (A--X) band at 336 nm is used to monitor ammonia, ammonium nitrate and ammonium sulfate. There are no major interferences in this spectral region. The sensitivity is approximately 100 ppb (1 second measurement) for ammonia in post flame gases and 100 ppb (mole fraction) for ammonium nitrate/sulfate in ambient air. Quenching of NH by the major combustion products does not limit the applicability of the detection method. Fluorescence from excited carbon atoms at 248 nm (1P 0 → 1S0) following photofragmentation measures particulate matter in a two-stroke gasoline engine and a four-stroke diesel engine. Fluorescence from CH (A2Delta → X 2pi, 431 nm) C2 (d3pig → a3piu, 468 nm) fragments is also observed. The atomic carbon fluorescence signal is proportional to the mass concentration of particles in the laser interrogation region. The 100-shot (1 second) detection limit for particles in the two-stroke gasoline engine exhaust is 0.5 ppb (volume fraction). The 100-shot detection limit for four-stroke diesel particulate matter is 0.2 ppb. Interferences from carbon monoxide and carbon dioxide are negligible. The ratios of atomic carbon, C2, and CH peaks provide information on the molecular forms of compounds condensed on or contained within the particles measured. The C/C2 signal ratio can be used to distinguish

  17. Real-time micro-scale temperature imaging at low cost based on fluorescent intensity ratio

    PubMed Central

    Xiong, Jianghao; Zhao, Mingshu; Han, Xiaotian; Cao, Zhongmin; Wei, Xiantao; Chen, Yonghu; Duan, Changkui; Yin, Min

    2017-01-01

    Real-time temperature imaging with high spatial resolution has been a challenging task but also one with wide potential applications. To achieve this task, temperature sensor is critical. Fluorescent materials stand out to be promising candidates due to their quick response and strong temperature dependence. However, former reported temperature imaging techniques with fluorescent materials are mainly based on point by point scanning, which cannot fulfill the requirement of real-time monitoring. Based on fluorescent intensity ratio (FIR) of two emission bands of SrB4O7:Sm2+, whose spatial distributions were simultaneously recorded by two cameras with special filters separately, real-time temperature imaging with high spatial resolution has been realized with low cost. The temperature resolution can reach about 2 °C in the temperature range from 120 to 280 °C; the spatial resolution is about 2.4 μm and the imaging time is as fast as one second. Adopting this system, we observed the dynamic change of a micro-scale thermal distribution on a printed circuit board (PCB). Different applications and better performance could also be achieved on this system with appropriate fluorescent materials and high sensitive CCD detectors according to the experimental environment. PMID:28145482

  18. Real-time micro-scale temperature imaging at low cost based on fluorescent intensity ratio

    NASA Astrophysics Data System (ADS)

    Xiong, Jianghao; Zhao, Mingshu; Han, Xiaotian; Cao, Zhongmin; Wei, Xiantao; Chen, Yonghu; Duan, Changkui; Yin, Min

    2017-02-01

    Real-time temperature imaging with high spatial resolution has been a challenging task but also one with wide potential applications. To achieve this task, temperature sensor is critical. Fluorescent materials stand out to be promising candidates due to their quick response and strong temperature dependence. However, former reported temperature imaging techniques with fluorescent materials are mainly based on point by point scanning, which cannot fulfill the requirement of real-time monitoring. Based on fluorescent intensity ratio (FIR) of two emission bands of SrB4O7:Sm2+, whose spatial distributions were simultaneously recorded by two cameras with special filters separately, real-time temperature imaging with high spatial resolution has been realized with low cost. The temperature resolution can reach about 2 °C in the temperature range from 120 to 280 °C the spatial resolution is about 2.4 μm and the imaging time is as fast as one second. Adopting this system, we observed the dynamic change of a micro-scale thermal distribution on a printed circuit board (PCB). Different applications and better performance could also be achieved on this system with appropriate fluorescent materials and high sensitive CCD detectors according to the experimental environment.

  19. Real-time 3D vibration measurements in microstructures

    NASA Astrophysics Data System (ADS)

    Kowarsch, Robert; Ochs, Wanja; Giesen, Moritz; Dräbenstedt, Alexander; Winter, Marcus; Rembe, Christian

    2012-04-01

    The real-time measurement of three-dimensional vibrations is currently a major interest of academic research and industrial device characterization. The most common and practical solution used so far consists of three single-point laser-Doppler vibrometers which measure vibrations of a scattering surface from three directions. The resulting three velocity vectors are transformed into a Cartesian coordinate system. This technique does also work for microstructures but has some drawbacks: (1) The surface needs to scatter light, (2) the three laser beams can generate optical crosstalk if at least two laser frequencies match within the demodulation bandwidth, and (3) the laser beams have to be separated on the surface under test to minimize optical crosstalk such that reliable measurements are possible. We present a novel optical approach, based on the direction-dependent Doppler effect, which overcomes all the drawbacks of the current technology. We have realized a demonstrator with a measurement spot of < 3.5 μm diameter that does not suffer from optical crosstalk because only one laser beam impinges the specimen surface while the light is collected from three different directions.

  20. An accurate assay for HCV based on real-time fluorescence detection of isothermal RNA amplification.

    PubMed

    Wu, Xuping; Wang, Jianfang; Song, Jinyun; Li, Jiayan; Yang, Yongfeng

    2016-09-01

    Hepatitis C virus (HCV) is one of the common reasons of liver fibrosis and hepatocellular carcinoma (HCC). Early, rapid and accurate HCV RNA detection is important to prevent and control liver disease. A simultaneous amplification and testing (SAT) assay, which is based on isothermal amplification of RNA and real-time fluorescence detection, was designed to optimize routine HCV RNA detection. In this study, HCV RNA and an internal control (IC) were amplified and analyzed simultaneously by SAT assay and detection of fluorescence using routine real-time PCR equipment. The assay detected as few as 10 copies of HCV RNA transcripts. We tested 705 serum samples with SAT, among which 96.4% (680/705) showed consistent results compared with routine real-time PCR. About 92% (23/25) discordant samples were confirmed to be same results as SAT-HCV by using a second real-time PCR. The sensitivity and specificity of SAT-HCV assay were 99.6% (461/463) and 100% (242/242), respectively. In conclusion, the SAT assay is an accurate test with a high specificity and sensitivity which may increase the detection rate of HCV. It is therefore a promising tool to diagnose HCV infection.

  1. Real-time Visualization and Quantification of Retrograde Cardioplegia Delivery using Near Infrared Fluorescent Imaging

    PubMed Central

    Rangaraj, Aravind T.; Ghanta, Ravi K.; Umakanthan, Ramanan; Soltesz, Edward G.; Laurence, Rita G.; Fox, John; Cohn, Lawrence H.; Bolman, R. M.; Frangioni, John V.; Chen, Frederick Y.

    2009-01-01

    Background and Aim of the Study Homogeneous delivery of cardioplegia is essential for myocardial protection during cardiac surgery. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. Methods A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in 5 ex-vivo normal porcine hearts and in 5 ex-vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. Results The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed that retrograde cardioplegia primarily distributed to the left ventricle and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior left ventricle. This deficiency was compensated for with retrograde cardioplegia supplementation. Conclusions Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated. PMID:19016995

  2. Automated real-time measurements of leukocyte chemotaxis.

    PubMed

    Hadjout, Nacima; Yin, Xiuyun; Knecht, David A; Lynes, Michael A

    2007-03-30

    We have previously described an automated system (ECIS/taxis) for measuring chemotactic movement of Dictyostelium amoebae in a folic acid gradient [Hadjout, N., Laevsky, G., Knecht, D.A. and Lynes, M.A., 2001. Automated real-time measurement of chemotactic cell motility. Biotechniques 31, 1130-1138.]. In the ECIS/taxis system, cells migrate in an under-agarose environment, and their position is monitored by determining the impedance change caused by cells crawling onto the surface of an electrode. In this report, we show that chemotaxis of primary and immortalized leukocytes in response to complement (C5a) could be measured using the ECIS/taxis system. Several modifications to the design of the target electrode were tested, and a linear electrode perpendicular to the direction of movement was found to increase the sensitivity and reliability of the assay. Using the optimized ECIS/taxis assay, the dose response of neutrophils and WBC 265-9C cells was established and compared to the Boyden chamber assay. The ECIS/taxis assay system can be used to compare the movement of different cell types, to assess the effect of complex chemotactic gradients, or to determine the effects of pharmaceuticals on chemotactic motility.

  3. Real-time temperature field measurement based on acoustic tomography

    NASA Astrophysics Data System (ADS)

    Bao, Yong; Jia, Jiabin; Polydorides, Nick

    2017-07-01

    Acoustic tomography can be used to measure the temperature field from the time-of-flight (TOF). In order to capture real-time temperature field changes and accurately yield quantitative temperature images, two improvements to the conventional acoustic tomography system are studied: simultaneous acoustic transmission and TOF collection along multiple ray paths, and an offline iteration reconstruction algorithm. During system operation, all the acoustic transceivers send modulated and filtered wideband Kasami sequences simultaneously to facilitate fast and accurate TOF measurements using cross-correlation detection. For image reconstruction, the iteration process is separated and executed offline beforehand to shorten computation time for online temperature field reconstruction. The feasibility and effectiveness of the developed methods are validated in the simulation study. The simulation results demonstrate that the proposed method can reduce the processing time per frame from 160 ms to 20 ms, while the reconstruction error remains less than 5%. Hence, the proposed method has great potential in the measurement of rapid temperature change with good temporal and spatial resolution.

  4. Development of fluorescent tracers for the real-time monitoring of renal function

    NASA Astrophysics Data System (ADS)

    Poreddy, Amruta R.; Asmelash, Bethel; Debreczeny, Martin P.; Fitch, Richard M.; Freskos, John N.; Galen, Karen P.; Gaston, Kimberly R.; Kostelc, James G.; Kumar, Rana; Marzan, Tim A.; Neumann, William L.; Rajagopalan, Raghavan; Schoenstein, Tasha M.; Shieh, Jeng-Jong; Wilcox, J. Micah; Wojdyla, Jolette K.; Dorshow, Richard B.

    2011-03-01

    Accurate measurement of glomerular filtration rate (GFR) at the bedside is highly desirable in order to assess renal function in real-time, which is currently an unmet clinical need. In our pursuit to develop exogenous fluorescent tracers as GFR markers, various hydrophilic derivatives of 3,6-diaminopyrazine-2,5-dicarboxylic acid with varying molecular weights and absorption/emission characteristics were synthesized. These include polyhydroxyalkyl based small molecules and poly(ethylene glycol) (PEG) substituted moderate molecular weight compounds, which were further sub-grouped into analogs having blue excitation with green emission, and relatively longer wavelength analogs having green excitation with orange emission. Lead compounds were identified in each of the four classes on the basis of structure- activity relationship studies, which included in vitro plasma protein binding, in vivo urine recovery of administered dose, and in vivo optical monitoring. The in vivo optical monitoring experiments with lead candidates have been correlated with plasma pharmacokinetic (PK) data for measurement of clearance and hence GFR. Renal clearance of these compounds, occurring exclusively via glomerular filtration, was established by probenecid blocking experiments. The renal clearance property of all these advanced candidates was superior to that of the iothalamate, which is currently an accepted standard for the measurement of GFR.

  5. A model system using confocal fluorescence microscopy for examining real-time intracellular sodium ion regulation.

    PubMed

    Lee, Jacqueline A; Collings, David A; Glover, Chris N

    2016-08-15

    The gills of euryhaline fish are the ultimate ionoregulatory tissue, achieving ion homeostasis despite rapid and significant changes in external salinity. Cellular handling of sodium is not only critical for salt and water balance but is also directly linked to other essential functions such as acid-base homeostasis and nitrogen excretion. However, although measurement of intracellular sodium ([Na(+)]i) is important for an understanding of gill transport function, it is challenging and subject to methodological artifacts. Using gill filaments from a model euryhaline fish, inanga (Galaxias maculatus), the suitability of the fluorescent dye CoroNa Green as a probe for measuring [Na(+)]i in intact ionocytes was confirmed via confocal microscopy. Cell viability was verified, optimal dye loading parameters were determined, and the dye-ion dissociation constant was measured. Application of the technique to freshwater- and 100% seawater-acclimated inanga showed salinity-dependent changes in branchial [Na(+)]i, whereas no significant differences in branchial [Na(+)]i were determined in 50% seawater-acclimated fish. This technique facilitates the examination of real-time changes in gill [Na(+)]i in response to environmental factors and may offer significant insight into key homeostatic functions associated with the fish gill and the principles of sodium ion transport in other tissues and organisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Compact wearable dual-mode imaging system for real-time fluorescence image-guided surgery

    NASA Astrophysics Data System (ADS)

    Zhu, Nan; Huang, Chih-Yu; Mondal, Suman; Gao, Shengkui; Huang, Chongyuan; Gruev, Viktor; Achilefu, Samuel; Liang, Rongguang

    2015-09-01

    A wearable all-plastic imaging system for real-time fluorescence image-guided surgery is presented. The compact size of the system is especially suitable for applications in the operating room. The system consists of a dual-mode imaging system, see-through goggle, autofocusing, and auto-contrast tuning modules. The paper will discuss the system design and demonstrate the system performance.

  7. Real-time observations of extreme-ultraviolet aerial images by fluorescence microimaging

    SciTech Connect

    La Fontaine, B. ); White, D.L. ); Wood, O.R. II ); MacDowell, A.A.; Tan, Z. ); Taylor, G.N. ); Tennant, D.M. ); Hulbert, S.L. )

    1994-11-01

    A new technique, fluorescence microimaging (FMI), using single-crystal phosphors was used to look directly at aerial images produced by an extreme-ultraviolet (EUV) camera operating at a wavelength of 139 A. The achieved spatial resolution was estimated to be [similar to]0.2 [mu]m. A comparison of this technique with the usual resist-exposure scanning electron microscopy inspection technique as a means of focusing a 20[times]EUV Schwarzschild camera was performed. FMI could in principle be improved to view fluorescent images with features as small as 0.07 [mu]m, in real time.

  8. Real-time dopamine measurement in awake monkeys.

    PubMed

    Schluter, Erik W; Mitz, Andrew R; Cheer, Joseph F; Averbeck, Bruno B

    2014-01-01

    Fast-scan cyclic voltammetry (FSCV) is often used to measure real-time dopamine (DA) concentrations in awake, behaving rodents. Extending this technique to work in monkeys would provide a platform for advanced behavioral studies and a primate model for preclinical research. The present study demonstrates the feasibility of DA recordings in two awake monkeys (Macaca mulatta) using a mixture of techniques adapted from rodent, primate and brain slice work. We developed a long carbon fiber electrode to operate in the larger primate brain. This electrode was lowered into the striatum each day using a recording chamber and a detachable micromanipulator system. A manipulator also moved one or more tungsten stimulating electrodes into either the nearby striatum or the ventral tegmental area/substantia nigra pars compacta (VTA/SNc). We developed an electrical stimulation controller to reduce artifacts during electrical stimulation. We also introduce a stimulation-based methodology for estimating distances between electrodes in the brain. Dopamine responses within the striatum were evoked by either stimulation of the striatum near the FSCV electrode, or stimulation within the VTA/SNc. Unexpected juice rewards also evoked dopamine responses in the ventral striatum. Thus, we demonstrate that robust dopamine responses can be recorded from awake, behaving primates with FSCV. In addition, we describe how a stimulation technique borrowed from the neuroprosthetics field can activate the distributed monkey midbrain dopamine system in a way that mimics rodent VTA stimulation.

  9. Real-time Intraoperative Fluorescent Lymphography: A New Technique for Lymphatic Sparing Surgery.

    PubMed

    Ietto, G; Amico, F; Soldini, G; Chiappa, C; Franchin, M; Iovino, D; Romanzi, A; Saredi, G; Cassinotti, E; Boni, L; Tozzi, M; Carcano, G

    2016-11-01

    Many surgical procedures can produce persistent lymphorrhea, lymphoceles, and lymphedema after lymph node and lymph vessel damage. Appropriate visualization of the lymphatic system is challenging. Indocyanine green (ICG) is a well-known nontoxic dye for lymphatic flow evaluation. ICG fluorescence-guided lymphography has emerged as a promising technique for intraoperative lymphatic mapping. Our goal was to develop a high spatial resolution, real-time intraoperative imaging technique to avoid or recognize early deep lymphatic vessel damage. We intraoperatively performed ICG fluorescence-guided lymphography during a kidney transplant. ICG was injected in the subcutaneous tissue of the patient's groin in the Scarpa's triangle. A dedicated laparoscopic high-definition camera system was used. Soon after ICG injection, the lymphatic vessels were identified in the abdominal retroperitoneal compartment as fluorescent linear structures running side by side to the iliac vessels. Surgical dissection was therefore performed, avoiding iatrogenic damage to major lymphatic structures. Another ICG injection at the end of the procedure confirmed that the lymphatic vessels were intact without lymph spread. Intraoperative lymphatic mapping with an ICG fluorescence-sensitive camera system is a safe and feasible procedure. ICG real-time fluorescence lymphography can be used to avoid or recognize early deep lymphatic vessel damage and reduce postoperative complications related to the lymphatic system. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Real-time head acceleration measurement in girls' youth soccer.

    PubMed

    Hanlon, Erin M; Bir, Cynthia A

    2012-06-01

    The purpose of the current study was to collect real-time head acceleration data for soccer impacts during girls' youth (U14) soccer play. Linear and angular head accelerations were collected during girls' youth soccer scrimmages using a wireless head acceleration measurement device (the Head Impact Telemetry System). After field data collection, each individual impact was analyzed. The type of impact, header or nonheader, was determined, and nonheader impacts were further assessed by the category of impact. The head injury criterion and resultant linear and angular accelerations were analyzed and compared with current injury tolerance values for all impacts. A total of 47 header and 20 nonheader impacts were observed during the study. The front of the head experienced more headers than the other locations (n = 17). Header impacts ranged in peak linear acceleration from 4.5 g to 62.9 g and in peak angular head acceleration from 444.8 to 8869.1 rad·s(-2). The majority of the nonheader impacts (40%) were player collisions with other players. Only one goalpost collision occurred, but it resulted in the highest peak angular acceleration (5179.5 rad·s(-2)) and was the only nonheader impact to exceed any of the tolerance levels. Head accelerations were found to exceed the majority of previous laboratory studies. None of the impacts exceeded linear acceleration tolerance values for concussion, but angular accelerations did exceed the suggested limits. Three angular acceleration measurements for heading events (4509.8, 5298.3, and 8869.1 rad·s(-2)) exceeded the concussion tolerance values, but no concussions were diagnosed during the study.

  11. Real-Time Near-Infrared Fluorescence-Guided Identification of the Ureters using Methylene Blue

    PubMed Central

    Matsui, Aya; Tanaka, Eiichi; Choi, Hak Soo; Kianzad, Vida; Gioux, Sylvain; Lomnes, Stephen J.; Frangioni, John V.

    2009-01-01

    Background The aim of this study was to determine whether the invisible near-infrared (NIR) fluorescence properties of methylene blue (MB), a dye already FDA-approved for other indications, could be exploited for real-time, intraoperative identification of the ureters. Methods The optical properties of MB were quantified in vitro. Open surgery and laparoscopic NIR fluorescence imaging systems were employed. Yorkshire pigs were injected intravenously with: 0.1 mg/kg MB (n = 8), 10 mg furosemide followed by 0.1 mg/kg MB (n = 6), or 0.5 mg/kg MB (n = 6). The contrast-to-background ratio (CBR) of the kidney and ureters, and MB concentration in urine, were quantified. Results Peak MB absorbance, emission, and intensity in urine occurred at 668 nm, 688 nm, and 20 μM, respectively. After intravenous injection, doses as low as 0.1 mg/kg MB provided prolonged imaging of the ureters, and a dose of 0.5 mg/kg provided statistically significant improvement of CBR. Pre-injection of furosemide increased urine volume but did not improve CBR. Laparoscopic identification of the ureter using MB NIR fluorescence was demonstrated. Conclusions Ureteral imaging using MB NIR fluorescence provides sensitive, real-time, intraoperative identification of the ureters during open and laparoscopic surgeries. PMID:20117811

  12. Real-time, near-infrared, fluorescence-guided identification of the ureters using methylene blue.

    PubMed

    Matsui, Aya; Tanaka, Eiichi; Choi, Hak Soo; Kianzad, Vida; Gioux, Sylvain; Lomnes, Stephen J; Frangioni, John V

    2010-07-01

    The aim of this study was to determine whether the invisible near-infrared (NIR) fluorescence properties of methylene blue (MB), a dye already approved by the U.S. Food and Drug Administration for other indications, could be exploited for real-time, intra-operative identification of the ureters. The optical properties of MB were quantified in vitro. Open surgery and laparoscopic NIR fluorescence imaging systems were employed. Yorkshire pigs were injected intravenously with 0.1-mg/kg MB (n = 8), 10-mg furosemide followed by 0.1-mg/kg MB (n = 6), or 0.5-mg/kg MB (n = 6). The contrast-to-background ratio (CBR) of the kidney and ureters, and the MB concentration in the urine, were quantified. Peak MB absorbance, emission, and intensity in urine occurred at 668 nm, 688 nm, and 20 mumol/L, respectively. After intravenous injection, doses as low as 0.1-mg/kg MB provided prolonged imaging of the ureters, and a dose of 0.5 mg/kg provided statistically significant improvement of CBR. The preinjection of furosemide increased urine volume but did not improve CBR. Laparoscopic identification of the ureter using MB NIR fluorescence was demonstrated. Ureteral imaging using MB NIR fluorescence provides sensitive, real-time, intra-operative identification of the ureters during open and laparoscopic surgeries. Copyright 2010 Mosby, Inc. All rights reserved.

  13. Real-time detection of cellular death receptor-4 activation by fluorescence resonance energy transfer.

    PubMed

    Dereli-Korkut, Zeynep; Gandhok, Harmeet; Zeng, Ling Ge; Waqas, Sidra; Jiang, Xuejun; Wang, Sihong

    2013-05-01

    Targeted therapy involving the activation of death receptors DR4 and/or DR5 by its ligand, TRAIL, can selectively induce apoptosis in certain tumor cells. In order to profile the dynamic activation or trimerization of TRAIL-DR4 in live cells in real-time, the development of an apoptosis reporter cell line is essential. Fluorescence resonance energy transfer (FRET) technology via a FRET pair, cyan fluorescence protein (CFP) and yellow fluorescence protein (YFP), was used in this study. DR4-CFP and DR4-YFP were stably expressed in human lung cancer PC9 cells. Flow cytometer sorting and limited dilution coupled with fluorescence microscopy were used to select a monoclonal reporter cell line with high and compatible expression levels of DR4-CFP and DR4-YFP. FRET experiments were conducted and FRET efficiencies were monitored according to the Siegel's YFP photobleaching FRET protocol. Upon TRAIL induction a significant increase in FRET efficiencies from 5% to 9% demonstrated the ability of the DR4-CFP/YFP reporter cell line in monitoring the dynamic activation of TRAIL pathways. 3D reconstructed confocal images of DR4-CFP/YFP reporter cells exhibited a colocalized expression of DR4-CFP and DR4-YFP mainly on cell membranes. FRET results obtained during this study complements the use of epi-fluorescence microscopy for FRET analysis. The real-time FRET analysis allows the dynamic profiling of the activation of TRAIL pathways by using the time-lapse fluorescence microscopy. Therefore, DR4-CFP/YFP PC9 reporter cells along with FRET technology can be used as a tool for anti-cancer drug screening to identify compounds that are capable of activating TRAIL pathways.

  14. A viscosity sensitive fluorescent dye for real-time monitoring of mitochondria transport in neurons.

    PubMed

    Baek, Yeonju; Park, Sang Jun; Zhou, Xin; Kim, Gyungmi; Kim, Hwan Myung; Yoon, Juyoung

    2016-12-15

    We present here a viscosity sensitive fluorescent dye, namely thiophene dihemicyanine (TDHC), that enables the specific staining of mitochondria. In comparison to the common mitochondria tracker (Mitotracker Deep Red, MTDR), this dye demonstrated its unique ability for robust staining of mitochondria with high photostability and ultrahigh signal-to-noise ratio (SNR). Moreover, TDHC also showed high sensitivity towards mitochondria membrane potential (ΔΨm) and intramitochondria viscosity change. Consequently, this dye was utilized in real-time monitoring of mitochondria transport in primary cortical neurons. Finally, the Two-Photon Microscopy (TPM) imaging ability of TDHC was also demonstrated.

  15. Innovative integrated system for real-time measurement of hybridization and melting on standard format microarrays.

    PubMed

    Marcy, Yann; Cousin, Pierre-Yves; Rattier, Maxime; Cerovic, Gordana; Escalier, Guilhem; Béna, Gilles; Guéron, Maurice; McDonagh, Lorcan; le Boulaire, Françoise; Bénisty, Henri; Weisbuch, Claude; Avarre, Jean-Christophe

    2008-06-01

    Despite the great popularity and potential of microarrays, their use for research and clinical applications is still hampered by lengthy and costly design and optimization processes, mainly because the technology relies on the end point measurement of hybridization. Thus, the ability to monitor many hybridization events on a standard microarray slide in real time would greatly expand the use and benefit of this technology, as it would give access to better prediction of probe performance and improved optimization of hybridization parameters. Although real-time hybridization and thermal denaturation measurements have been reported, a complete walk-away system compatible with the standard format of microarrays is still unavailable. To address this issue, we have designed a biochip tool that combines a hybridization station with active mixing capability and temperature control together with a fluorescence reader in a single compact benchtop instrument. This integrated live hybridization machine (LHM) allows measuring in real time the hybridization of target DNA to thousands of probes simultaneously and provides excellent levels of detection and superior sequence discrimination. Here we show on an environmental single nucleotide polymorphism (SNP) model system that the LHM enables a variety of experiments unachievable with conventional biochip tools.

  16. A real time interferometry system for unsteady flow measurements

    NASA Technical Reports Server (NTRS)

    Brock, N. J.; Chandrasekhara, M. S.; Carr, L. W.

    1991-01-01

    A simple real-time interferometer system was developed for use in dynamic stall and other unsteady flow research at compressible flow speeds. A conventional schlieren system was modified to operate as a point diffraction interferometer. The implementation of this interferometer is discussed, and results of trials with different point diffractors are presented in this paper. The performance of the interferometer under various flow conditions was investigated. Results are presented which show the effects of the interferometer parameters such as pinhole size and pinhole-plate optical density on the performance of the system.

  17. Real-time assessment of breast surgical margins with fluorescence-guided microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Iftimia, Nicusor V.; Park, Jesung; Maguluri, Gopi N.; Krishnamurthy, Savitri

    2017-02-01

    A novel multimodal optical imaging approach for real-time assessment of surgical margins on breast cancer lumpectomy specimens is presented. Our approach is to target cancer cells using an optically silent peptide substrate containing two (NIR) fluorochromes, internally quenched, which are cleaved by highly expressed breast cancer enzymes, like urokinase-type plasminogen activator (uPA). Thus this agent becomes highly fluorescent only on the cancer area when the specimen is excited by a NIR laser beam. A fluorescence imager is used to highlight cancer-suspect margins on the surgical specimen, while high-resolution optical coherence tomography (OCT) imaging is used to visualize tissue morphology on the highlighted areas and confirm or rule out cancer presence. This technology will hopefully increase the success rate of cancer surgeries, reduce the risk of cancer recurrence and significantly reduce US healthcare costs.

  18. Real-time fluorescence assays to monitor duplex unwinding and ATPase activities of helicases.

    PubMed

    Özeş, Ali R; Feoktistova, Kateryna; Avanzino, Brian C; Baldwin, Enoch P; Fraser, Christopher S

    2014-07-01

    Many physiological functions of helicases are dependent on their ability to unwind nucleic acid duplexes in an ATP-dependent fashion. Determining the kinetic frameworks of these processes is crucial to understanding how these proteins function. We recently developed a fluorescence assay to monitor RNA duplex unwinding by DEAD-box helicases in real time. In this assay, two fluorescently modified short reporter oligonucleotides are annealed to an unmodified RNA loading strand of any length so that the fluorescent moieties of the two reporters find themselves in close proximity to each other and fluorescence is quenched. One reporter is modified with cyanine 3 (Cy3), whereas the other is modified with a spectrally paired black-hole quencher (BHQ). As the helicase unwinds the loading strand, the enzyme displaces the Cy3-modified reporter, which will bind to a capture or competitor DNA strand, permanently separating it from the BHQ-modified reporter. Complete separation of the Cy3-modified reporter strand is thus detected as an increase in total fluorescence. This assay is compatible with reagentless biosensors to monitor ATPase activity so that the coupling between ATP hydrolysis and duplex unwinding can be determined. With the protocol described, obtaining data and analyzing results of unwinding and ATPase assays takes ∼4 h.

  19. The application of time-gated fluorescence spectroscopy to the real-time monitoring of biological metabolism

    NASA Astrophysics Data System (ADS)

    Long, Zachary; Urayama, Paul

    2012-10-01

    A time-gated fluorescence spectroscopy system capable of nanosecond gating and picosecond control of gate delays is presented. Used in conjunction with pulsed excitation, the system is capable of tracking the temporal evolution of the fluorescence spectrum from solution samples. The system uses a nitrogen discharge laser as the excitation source and a time-gated intensified CCD detector coupled to a spectrograph. Precise synchronization between the laser pulse and ICCD gate is achieved using a constant-fraction optical discriminator. System characterizations are presented, for example, the ability to both spectrally and temporally resolve the content of fluorophore mixtures is confirmed. Biotechnological applications are highlighted, including gated spectroscopy for the real time monitoring of metabolic activity via measurement of endogenous cellular fluorescence.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  2. Fluorescence particle detector for real-time quantification of viable organisms in air

    NASA Astrophysics Data System (ADS)

    Luoma, Greg; Cherrier, Pierre P.; Piccioni, Marc; Tanton, Carol; Herz, Steve; DeFreez, Richard K.; Potter, Michael; Girvin, Kenneth L.; Whitney, Ronald

    2002-02-01

    The ability to detect viable organisms in air in real time is important in a number of applications. Detecting high levels of airborne organisms in hospitals can prevent post-operative infections and the spread of diseases. Monitoring levels of airborne viable organisms in pharmaceutical facilities can ensure safe production of drugs or vaccines. Monitoring airborne bacterial levels in meat processing plants can help to prevent contamination of food products. Monitoring the level of airborne organisms in bio-containment facilities can ensure that proper procedures are being followed. Finally, detecting viable organisms in real time is a key to defending against biological agent attacks. This presentation describes the development and performance of a detector, based on fluorescence particle counting technology, where an ultraviolet laser is used to count particles by light scattering and elicit fluorescence from specific biomolecules found only in living organisms. The resulting detector can specifically detect airborne particles containing living organisms from among the large majority of other particles normally present in air. Efforts to develop the core sensor technology, focusing on integrating an UV laser with a specially designed particle-counting cell will be highlighted. The hardware/software used to capture the information from the sensor, provide an alarm in the presence of an unusual biological aerosol content will also be described. Finally, results from experiments to test the performance of the detector will be presented.

  3. PRIMAS: real-time image-based motion measurement system

    NASA Astrophysics Data System (ADS)

    Furnee, E. Hans

    1990-08-01

    The PRIMAS system derives from a long line of development at Delft University of Technology , originating from [1] with subsequent innovations such as strobed illumination (1974) of reflective markers, to obtain the simultaneous, equidistant, periodic sampling of all marker positions; real-time estimation of the marker centroids from the full, digitized, contours (1984) to retain the on-line data reduction, while enhancing the resolution; interfacing to industry-standard AT type personal computers, with modest disk requirements and no buffering, even for long data runs; 100 Hz, 0.1 ms integration time, electronically-shuttered TV cameras, to get an optimum marker contrast in high ambient or outdoor light conditions (1986). System specifications include a precision of typ. 1:18000 (X) for 2-D coordinate noise or repeatability. With the 100 Hz sample rate this implies an unprecedented spatio-temporal resolution [2]. This favors 3-D reconstruction, as well as a low noise propagation in the estimation of first and higher order derivatives, as are routinely required in biomechanics analysis. The latest feature is real-time marker identification by a software module within the data acquisition program. This option, for the not too complex situations, is feasible only by the data reduction inherent in on-line marker centroid processing. The 3-D calibration, reconstruction and further analytical and display programs are available in the ASYST 3.2 Scientific Language System. A source code option caters for customer extensions. The internal VME/VSB system bus allows the basic dual or quad camera 3-D systems to be readily expanded to larger configurations.

  4. Real-time measurements, rare events and photon economics

    NASA Astrophysics Data System (ADS)

    Jalali, B.; Solli, D. R.; Goda, K.; Tsia, K.; Ropers, C.

    2010-07-01

    Rogue events otherwise known as outliers and black swans are singular, rare, events that carry dramatic impact. They appear in seemingly unconnected systems in the form of oceanic rogue waves, stock market crashes, evolution, and communication systems. Attempts to understand the underlying dynamics of such complex systems that lead to spectacular and often cataclysmic outcomes have been frustrated by the scarcity of events, resulting in insufficient statistical data, and by the inability to perform experiments under controlled conditions. Extreme rare events also occur in ultrafast physical sciences where it is possible to collect large data sets, even for rare events, in a short time period. The knowledge gained from observing rare events in ultrafast systems may provide valuable insight into extreme value phenomena that occur over a much slower timescale and that have a closer connection with human experience. One solution is a real-time ultrafast instrument that is capable of capturing singular and randomly occurring non-repetitive events. The time stretch technology developed during the past 13 years is providing a powerful tool box for reaching this goal. This paper reviews this technology and discusses its use in capturing rogue events in electronic signals, spectroscopy, and imaging. We show an example in nonlinear optics where it was possible to capture rare and random solitons whose unusual statistical distribution resemble those observed in financial markets. The ability to observe the true spectrum of each event in real time has led to important insight in understanding the underlying process, which in turn has made it possible to control soliton generation leading to improvement in the coherence of supercontinuum light. We also show a new class of fast imagers which are being considered for early detection of cancer because of their potential ability to detect rare diseased cells (so called rogue cells) in a large population of healthy cells.

  5. Assessment of Spectroscopic, Real-time Ion Thruster Grid Erosion-rate Measurements

    NASA Technical Reports Server (NTRS)

    Domonkos, Matthew T.; Stevens, Richard E.

    2000-01-01

    The success of the ion thruster on the Deep Space One mission has opened the gate to the use of primary ion propulsion. Many of the projected planetary missions require throughput and specific impulse beyond those qualified to date. Spectroscopic, real-time ion thruster grid erosion-rate measurements are currently in development at the NASA Glenn Research Center. A preliminary investigation of the emission spectra from an NSTAR derivative thruster with titanium grid was conducted. Some titanium lines were observed in the discharge chamber; however, the signals were too weak to estimate the erosion of the screen grid. Nevertheless, this technique appears to be the only non-intrusive real-time means to evaluate screen grid erosion, and improvement of the collection optics is proposed. Direct examination of the erosion species using laser-induced fluorescence (LIF) was determined to be the best method for a real-time accelerator grid erosion diagnostic. An approach for a quantitative LIF diagnostic was presented.

  6. Lysosome triggered near-infrared fluorescence imaging of cellular trafficking processes in real time

    PubMed Central

    Grossi, Marco; Morgunova, Marina; Cheung, Shane; Scholz, Dimitri; Conroy, Emer; Terrile, Marta; Panarella, Angela; Simpson, Jeremy C.; Gallagher, William M.; O'Shea, Donal F.

    2016-01-01

    Bioresponsive NIR-fluorophores offer the possibility for continual visualization of dynamic cellular processes with added potential for direct translation to in vivo imaging. Here we show the design, synthesis and lysosome-responsive emission properties of a new NIR fluorophore. The NIR fluorescent probe design differs from typical amine functionalized lysosomotropic stains with off/on fluorescence switching controlled by a reversible phenol/phenolate interconversion. Emission from the probe is shown to be highly selective for the lysosomes in co-imaging experiments using a HeLa cell line expressing the lysosomal-associated membrane protein 1 fused to green fluorescent protein. The responsive probe is capable of real-time continuous imaging of fundamental cellular processes such as endocytosis, lysosomal trafficking and efflux in 3D and 4D. The advantage of the NIR emission allows for direct translation to in vivo tumour imaging, which is successfully demonstrated using an MDA-MB-231 subcutaneous tumour model. This bioresponsive NIR fluorophore offers significant potential for use in live cellular and in vivo imaging, for which currently there is a deficit of suitable molecular fluorescent tools. PMID:26927507

  7. New fluorescent nucleosides for real-time exploration of nucleic acids

    NASA Astrophysics Data System (ADS)

    Tor, Yitzhak

    2010-02-01

    Nucleic acids experience a variety of perturbations. These may include strand cleavage and ligation, local conformational changes, base flipping, as well as structural and environmental perturbations that are induced upon protein and low MW ligand binding. Since the native nucleobases are practically non-emissive, synthetic fluorescent nucleoside analogs that are sensitive to their local environment have become powerful tools for investigating nucleic acids structure, dynamics, recognition and damage. Our criteria for "ideal" fluorescent nucleoside analogs include: (a) high structural similarity to the native nucleobases to faithfully mimic their size and shape, as well as hybridization and recognition properties; (b) red shifted absorption (> 290 nm) to minimize overlap with the absorption of the natural bases; (c) red shifted emission (preferably in the visible range); (d) reasonable emission quantum efficiency; and, importantly, (e) sensitivity/responsiveness of one or all photophysical parameters (λem and/or ΦF, τ) to changes in the probe's microenvironment. The design and synthesis of new fluorescent isosteric nucleobase analogs and their utilization for the fabrication of "real-time" fluorescence-based discovery and detection assays are outlined.

  8. Initial formal toxicity evaluation of APC-2, a novel fluorescent tracer agent for real-time measurement of glomerular filtration rate in preparation for a first-in-man clinical trial

    NASA Astrophysics Data System (ADS)

    Bugaj, Joseph E.; Dorshow, Richard B.

    2014-03-01

    The fluorescent tracer agent 2,5-bis[N-(1-carboxy-2-hydroxy)]carbamoyl-3,6-diaminopyrazine, designated APC-2, has been developed with properties and attributes necessary for use as a direct measure of glomerular filtration rate (GFR). Comparison to known standard exogenous GFR agents in animal models has demonstrated an excellent correlation. A clinical trial to demonstrate this same correlation in humans is in preparation. A battery of formal toxicity tests necessary for regulatory clearance to proceed with a clinical trial has been recently completed on this new fluorescent tracer agent. These include single dose toxicity studies in rats and dogs to determine overall toxicity and toxicokinetics of the compound. Blood compatibility, mutation assay, chromosomal aberration assay, and several other assays were also completed. Toxicity assessments were based on mortality, clinical signs, body weight, food consumption and anatomical pathology. Blood samples were collected to assess pharmacokinetic parameters including half-life, area under the curve, and clearance. Urine samples were collected to assess distribution. Doses of up to 200-300 times the estimated human dose were administered. No test-article related effects were noted on body weight, food consumption, ophthalmic observations and no abnormal pathology was seen in either macroscopic or microscopic evaluations of any organs or tissues. All animals survived to scheduled sacrifice. Transient discoloration of skin and urine was noted at the higher dose levels in both species as expected from a highly fluorescent compound and was not considered pathological. Thus initial toxicology studies of this new fluorescent tracer agent APC-2 have resulted in no demonstrable pathological test article concerns.

  9. Real-time fluorescence assays of alkaline phosphatase and ATP sulfurylase activities based on a novel PPi fluorescent probe.

    PubMed

    Wang, Xiaobo; Zhang, Zhiyang; Ma, Xiaoyan; Wen, Jinghan; Geng, Zhirong; Wang, Zhilin

    2015-05-01

    An anthracene-armed tetraaza macrocyclic fluorescent probe 3-(9-anthrylmethyl)-3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene(l) for detecting Zn(2+) in aqueous medium was synthesized. L-Zn(2+) complex, showed selectivity toward pyrophosphate ion (PPi) by quenching the fluorescence in aqueous HEPES buffer (pH 7.4). Furthermore, L-Zn(2+) was also used to set up a real-time fluorescence assay for monitoring enzyme activities of alkaline phosphatase (ALP) and adenosine triphosphate sulfurylase (ATPS). In the presence of ALP inhibitor Na3VO4 and ATPS inhibitor chlorate, two enzymes activities decreased obviously, respectively.

  10. Real-time fluorescence loop-mediated isothermal amplification for the diagnosis of hemorrhagic enteritis virus.

    PubMed

    Liu, Xuemei; Li, Yuhao; Xu, Chenggang; Qin, Jianru; Hao, Jianyong; Feng, Min; Tan, Liqiang; Jia, Weixin; Liao, Ming; Cao, Weisheng

    2014-04-01

    Suspected cases of hemorrhagic enteritis associated with hemorrhagic enteritis virus (HEV) are becoming more frequent among yellow chickens in the Guangdong Province of China. In this study, we have developed a one-step, ecumenical, real-time fluorescence loop-mediated isothermal amplification (RealAmp) assay for the rapid diagnosis of HEV. The RealAmp assay was performed at 63°C and reduced the assay time to 15min, using a simple and portable device, the ESE-Quant Tube Scanner. The detection limit of DNA was 1fg/μl, and the detection was specific only to HEV. We also used nested PCR to evaluate the application of the RealAmp assay. The coincidence rate of the two methods was 100%. Our data indicated that the RealAmp assay provides a sensitive, specific, and user-friendly diagnostic tool for the identification and quantification of HEV for field diagnosis and in laboratory research.

  11. A fluorescence-based quantitative real-time PCR assay for accurate Pocillopora damicornis species identification

    NASA Astrophysics Data System (ADS)

    Thomas, Luke; Stat, Michael; Evans, Richard D.; Kennington, W. Jason

    2016-09-01

    Pocillopora damicornis is one of the most extensively studied coral species globally, but high levels of phenotypic plasticity within the genus make species identification based on morphology alone unreliable. As a result, there is a compelling need to develop cheap and time-effective molecular techniques capable of accurately distinguishing P. damicornis from other congeneric species. Here, we develop a fluorescence-based quantitative real-time PCR (qPCR) assay to genotype a single nucleotide polymorphism that accurately distinguishes P. damicornis from other morphologically similar Pocillopora species. We trial the assay across colonies representing multiple Pocillopora species and then apply the assay to screen samples of Pocillopora spp. collected at regional scales along the coastline of Western Australia. This assay offers a cheap and time-effective alternative to Sanger sequencing and has broad applications including studies on gene flow, dispersal, recruitment and physiological thresholds of P. damicornis.

  12. Real-time assays with molecular beacons and other fluorescent nucleic acid hybridization probes.

    PubMed

    Marras, Salvatore A E; Tyagi, Sanjay; Kramer, Fred Russell

    2006-01-01

    A number of formats for nucleic acid hybridization have been developed to identify DNA and RNA sequences that are involved in cellular processes and that aid in the diagnosis of genetic and infectious diseases. The introduction of hybridization probes with interactive fluorophore pairs has enabled the development of homogeneous hybridization assays for the direct identification of nucleic acids. A change in the fluorescence of these probes indicates the presence of a target nucleic acid, and there is no need to separate unbound probes from hybridized probes. The advantages of homogeneous hybridization assays are their speed and simplicity. In addition, homogeneous assays can be combined with nucleic acid amplification, enabling the detection of rare target nucleic acids. These assays can be followed in real time, providing quantitative determination of target nucleic acids over a broad range of concentrations.

  13. Real-time near-field terahertz imaging with atomic optical fluorescence

    NASA Astrophysics Data System (ADS)

    Wade, C. G.; Šibalić, N.; de Melo, N. R.; Kondo, J. M.; Adams, C. S.; Weatherill, K. J.

    2017-01-01

    Terahertz (THz) near-field imaging is a flourishing discipline, with applications from fundamental studies of beam propagation to the characterization of metamaterials and waveguides. Beating the diffraction limit typically involves rastering structures or detectors with length scale shorter than the radiation wavelength; in the THz domain this has been achieved using a number of techniques including scattering tips and apertures. Alternatively, mapping THz fields onto an optical wavelength and imaging the visible light removes the requirement for scanning a local probe, speeding up image collection times. Here, we report THz-to-optical conversion using a gas of highly excited Rydberg atoms. By collecting THz-induced optical fluorescence we demonstrate a real-time image of a THz standing wave and use well-known atomic properties to calibrate the THz field strength.

  14. Real-Time Fluorescence Measurements of ROS and [Ca2+] in Ischemic / Reperfused Rat Hearts: Detectable Increases Occur only after Mitochondrial Pore Opening and Are Attenuated by Ischemic Preconditioning

    PubMed Central

    Rossbach, Andreas; Halestrap, Andrew P

    2016-01-01

    Mitochondrial permeability transition pore (mPTP) opening is critical for ischemia / reperfusion (I/R) injury and is associated with increased [Ca2+] and reactive oxygen species (ROS). Here we employ surface fluorescence to establish the temporal sequence of these events in beating perfused hearts subject to global I/R. A bespoke fluorimeter was used to synchronously monitor surface fluorescence and reflectance of Langendorff-perfused rat hearts at multiple wavelengths, with simultaneous measurements of hemodynamic function. Potential interference by motion artefacts and internal filtering was assessed and minimised. Re-oxidation of NAD(P)H and flavoproteins on reperfusion (detected using autofluorescence) was rapid (t0.5 < 15 s) and significantly slower following ischemic preconditioning (IP). This argues against superoxide production from reduced Complex 1 being a critical mediator of initial mPTP opening during early reperfusion. Furthermore, MitoPY1 (a mitochondria-targeted H2O2-sensitive fluorescent probe) and aconitase activity measurements failed to detect matrix ROS increases during early reperfusion. However, two different fluorescent cytosolic ROS probes did detect ROS increases after 2–3 min of reperfusion, which was shown to be after initiation of mPTP opening. Cyclosporin A (CsA) and IP attenuated these responses and reduced infarct size. [Ca2+]i (monitored with Indo-1) increased progressively during ischemia, but dropped rapidly within 90 s of reperfusion when total mitochondrial [Ca2+] was shown to be increased. These early changes in [Ca2+] were not attenuated by IP, but substantial [Ca2+] increases were observed after 2–3 min reperfusion and these were prevented by both IP and CsA. Our data suggest that the major increases in ROS and [Ca2+] detected later in reperfusion are secondary to mPTP opening. If earlier IP-sensitive changes occur that might trigger initial mPTP opening they are below our limit of detection. Rather, we suggest that IP

  15. Wide-field near-infrared fluorescence endoscope for real-time in vivo imaging

    NASA Astrophysics Data System (ADS)

    Liu, Zhongyao; Miller, Sharon J.; Joshi, Bishnu P.; Wang, Thomas D.

    2012-02-01

    A diode-pumped solid state laser is used to deliver excitation at λex = 671 nm. The beam is expanded by a pair of relay lenses (f1 = 30 and f2 = 50 mm) to 3 mm diameter, filling the aperture of a fluid light cable that is coupled to a Hopkins II rigid endoscope. Near-infrared fluorescence images are collected by the endoscope and transmitted by another set of relay lenses onto a CCD detector that has dimensions of 8.7x6.9 mm2 (1388x1040 pixels). A zoom lens system (F#1.6-16 aperture) with a tunable focal length (20-100 mm) magnifies the image to fill the dimensions of the CCD. A band pass filter allows fluorescence with spectral range λem = 696 to 736 nm to be collected. The system achieves a resolution of 9.8 μm and field-of-view of 3.6 mm at a distance of 2.5 mm between the distal end of the endoscope and the tissue. Images are collected at a rate of 10 frames per second. A filter wheel is incorporated into the handle of the instrument housing to rapidly switch between reflectance and fluorescence images. Cy5.5-labeled peptides were delivered through the 1 mm diameter instrument channel in the endoscope. Near-infrared fluorescence images demonstrated specific peptide binding to spontaneous adenomas that developed beginning at 2 months of age in a genetically-engineered mouse with mutation of one allele in the APC gene. This integrated methodology represents a powerful tool that can achieve real time detection of disease in the colon and other hollow organs.

  16. A real-time fluorescence method to monitor the melting of duplex DNA during transcription initiation by RNA polymerase.

    PubMed

    Matlock, D L; Heyduk, T

    1999-05-15

    The melting of duplex DNA in the vicinity of the transcription start site is an essential step of transcription initiation. Here we describe a fluorescent promoter technique which allows the melting of promoter DNA to be observed in a real-time manner with high sensitivity. We have constructed a 114-bp lacUV5 promoter fragment (-89 to +25) which contains a fluorescence probe in the region between the -10 consensus hexamer and the transcription start site. This region was chosen to incorporate a fluorescence probe as it undergoes strand separation subsequent to binding RNA polymerase (RNAP) (i.e., open complex formation). Upon mixing RNAP and fluorochrome-labeled promoter a time-dependent biphasic change in fluorescence was observed. The second slower component was shown to be due to the open complex by comparing the fluorescence data with the kinetics of open complex formation as measured by using alternative methods of open complex detection. The rate constants for open complex formation and dissociation were determined and found to be in excellent agreement with previously reported values. The techniques presented herein can generally be applied to other systems. Furthermore, this method will serve as an important research tool as well as it could be used in designing high-throughput assays involving transcription complexes. Copyright 1999 Academic Press.

  17. Real-time measurements of amino acid and protein hydroperoxides using coumarin boronic acid.

    PubMed

    Michalski, Radoslaw; Zielonka, Jacek; Gapys, Ewa; Marcinek, Andrzej; Joseph, Joy; Kalyanaraman, Balaraman

    2014-08-08

    Hydroperoxides of amino acid and amino acid residues (tyrosine, cysteine, tryptophan, and histidine) in proteins are formed during oxidative modification induced by reactive oxygen species. Amino acid hydroperoxides are unstable intermediates that can further propagate oxidative damage in proteins. The existing assays (oxidation of ferrous cation and iodometric assays) cannot be used in real-time measurements. In this study, we show that the profluorescent coumarin boronic acid (CBA) probe reacts with amino acid and protein hydroperoxides to form the corresponding fluorescent product, 7-hydroxycoumarin. 7-Hydroxycoumarin formation was catalase-independent. Based on this observation, we have developed a fluorometric, real-time assay that is adapted to a multiwell plate format. This is the first report showing real-time monitoring of amino acid and protein hydroperoxides using the CBA-based assay. This approach was used to detect protein hydroperoxides in cell lysates obtained from macrophages exposed to visible light and photosensitizer (rose bengal). We also measured the rate constants for the reaction between amino acid hydroperoxides (tyrosyl, tryptophan, and histidine hydroperoxides) and CBA, and these values (7-23 M(-1) s(-1)) were significantly higher than that measured for H2O2 (1.5 M(-1) s(-1)). Using the CBA-based competition kinetics approach, the rate constants for amino acid hydroperoxides with ebselen, a glutathione peroxidase mimic, were also determined, and the values were within the range of 1.1-1.5 × 10(3) M(-1) s(-1). Both ebselen and boronates may be used as small molecule scavengers of amino acid and protein hydroperoxides. Here we also show formation of tryptophan hydroperoxide from tryptophan exposed to co-generated fluxes of nitric oxide and superoxide. This observation reveals a new mechanism for amino acid and protein hydroperoxide formation in biological systems.

  18. Real-time Measurements of Amino Acid and Protein Hydroperoxides Using Coumarin Boronic Acid*

    PubMed Central

    Michalski, Radoslaw; Zielonka, Jacek; Gapys, Ewa; Marcinek, Andrzej; Joseph, Joy; Kalyanaraman, Balaraman

    2014-01-01

    Hydroperoxides of amino acid and amino acid residues (tyrosine, cysteine, tryptophan, and histidine) in proteins are formed during oxidative modification induced by reactive oxygen species. Amino acid hydroperoxides are unstable intermediates that can further propagate oxidative damage in proteins. The existing assays (oxidation of ferrous cation and iodometric assays) cannot be used in real-time measurements. In this study, we show that the profluorescent coumarin boronic acid (CBA) probe reacts with amino acid and protein hydroperoxides to form the corresponding fluorescent product, 7-hydroxycoumarin. 7-Hydroxycoumarin formation was catalase-independent. Based on this observation, we have developed a fluorometric, real-time assay that is adapted to a multiwell plate format. This is the first report showing real-time monitoring of amino acid and protein hydroperoxides using the CBA-based assay. This approach was used to detect protein hydroperoxides in cell lysates obtained from macrophages exposed to visible light and photosensitizer (rose bengal). We also measured the rate constants for the reaction between amino acid hydroperoxides (tyrosyl, tryptophan, and histidine hydroperoxides) and CBA, and these values (7–23 m−1 s−1) were significantly higher than that measured for H2O2 (1.5 m−1 s−1). Using the CBA-based competition kinetics approach, the rate constants for amino acid hydroperoxides with ebselen, a glutathione peroxidase mimic, were also determined, and the values were within the range of 1.1–1.5 × 103 m−1 s−1. Both ebselen and boronates may be used as small molecule scavengers of amino acid and protein hydroperoxides. Here we also show formation of tryptophan hydroperoxide from tryptophan exposed to co-generated fluxes of nitric oxide and superoxide. This observation reveals a new mechanism for amino acid and protein hydroperoxide formation in biological systems. PMID:24928516

  19. Continuous-flow C. elegans fluorescence expression analysis with real-time image processing through microfluidics.

    PubMed

    Yan, Yuanjun; Boey, Daryl; Ng, Li Theng; Gruber, Jan; Bettiol, Andrew; Thakor, Nitish V; Chen, Chia-Hung

    2016-03-15

    The nematode Caenorhabditis elegans has become an essential model organism in neuroscience research because of its stereotyped anatomy, relevance to human biology, and capacity for genetic manipulation. To solve the intrinsic challenges associated with performing manual operations on C. elegans, many automated chip designs based on immobilization-imaging-release approaches have been proposed. These designs are prone to limitations such as the exertion of physical stress on the worms and limited throughput. In this work, a continuous-flow, high-throughput, automated C. elegans analyzer based on droplet encapsulation and real-time image processing was developed to analyze fluorescence expression in worms. To demonstrate its capabilities, two strains of C. elegans nematodes with different levels of expression of green fluorescent protein (GFP) were first mixed in a buffer solution. The worms were encapsulated in water-in-oil droplets to restrict random locomotion. The droplets were closely packed in a two-layer polydimethylsiloxane (PDMS) platform and were flowed through a narrow straight channel, in which a region of interest (ROI) was defined and continuously recorded by a frame acquisition device. Based on the number of pixels counted in the selected color range, our custom software analyzed GFP expression to differentiate between two strains with nearly 100% accuracy and a throughput of 0.5 seconds/worm.

  20. Real-time fluorescence imaging of the DNA damage repair response during mitosis.

    PubMed

    Miwa, Shinji; Yano, Shuya; Yamamoto, Mako; Matsumoto, Yasunori; Uehara, Fuminari; Hiroshima, Yukihiko; Toneri, Makoto; Murakami, Takashi; Kimura, Hiroaki; Hayashi, Katsuhiro; Yamamoto, Norio; Efimova, Elena V; Tsuchiya, Hiroyuki; Hoffman, Robert M

    2015-04-01

    The response to DNA damage during mitosis was visualized using real-time fluorescence imaging of focus formation by the DNA-damage repair (DDR) response protein 53BP1 linked to green fluorescent protein (GFP) (53BP1-GFP) in the MiaPaCa-2(Tet-On) pancreatic cancer cell line. To observe 53BP1-GFP foci during mitosis, MiaPaCa-2(Tet-On) 53BP1-GFP cells were imaged every 30 min by confocal microscopy. Time-lapse imaging demonstrated that 11.4 ± 2.1% of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells had increased focus formation over time. Non-mitotic cells did not have an increase in 53BP1-GFP focus formation over time. Some of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells with focus formation became apoptotic. The results of the present report suggest that DNA strand breaks occur during mitosis and undergo repair, which may cause some of the mitotic cells to enter apoptosis in a phenomenon possibly related to mitotic catastrophe.

  1. Research progress on real-time measurement of soil attributes for precision agriculture

    USDA-ARS?s Scientific Manuscript database

    In order to develop a real-time analyzer for soil attributes, this study analyzed the needs for real-time measurement of soil attributes and reviewed major soil attributes to be measured in soil testing and commonly-used testing methods, including traditional chemical analysis, methods based on elec...

  2. Real-time fluorescence Loop-Mediated Isothermal Amplification (LAMP) for rapid and reliable diagnosis of pulmonary tuberculosis.

    PubMed

    Cao, Donglin; Hu, Liangshan; Lin, Maorui; Li, Mingyou; Ye, Zebing; Sun, Hongtao; Huang, Jiwei; Yang, Huawen; Tian, Junzhang

    2015-02-01

    A reliable, simple and rapid diagnostic method that can be helpful in pulmonary tuberculosis diagnosis is urgently needed. Loop-mediated Isothermal Amplification (LAMP) allows DNA to be amplified rapidly at a constant temperature. In this study, real-time fluorescence LAMP was evaluated to rapidly detect Mycobacterium tuberculosis in sputum and was compared to the performance of real-time fluorescence quantitative PCR (Q-PCR). All the standard MTB strains were successfully detected and limit of detection (LOD) was 10(2)CFU/mL by real-time fluorescence LAMP within 20min. In light of MTB in sputum, the real-time fluorescence LAMP method yielded a sensitivity of 98.0% and a specificity of 78.3%, compared to Q-PCR assay, which yielded a sensitivity of 96.0% and a specificity of 82.6% for PTB diagnosis. There was an excellent overall agreement between LAMP and Q-PCR for PTB (κ=0.315) and non-PTB (κ=0.862). Therefore, the real-time fluorescence LAMP assay is a rapid, sensitive, and specific method to detect pulmonary tuberculosis.

  3. Real-time Measurements of Biological Particles at Several Continental Sites using the WIBS-4A

    NASA Astrophysics Data System (ADS)

    McMeeking, G. R.; Kok, G. L.; Petters, M. D.; Wright, T.; Hader, J.; Mccubbin, I. B.; Hallar, A. G.; Twohy, C. H.; Toohey, D. W.; DeMott, P. J.; McCluskey, C.; Baumgardner, D.

    2013-12-01

    Biological particles (bacteria, fungi/fungal spores, viruses, algae and fragments of biological material) may play a significant role in modifying cloud properties by acting as ice nuclei and thus have an indirect effect on climate forcing. Little is known, however, regarding the abundance and distribution of biological particles and their importance to cloud microphysics in different environments. On-line, continuous measurement systems offer the potential to measure biological systems at high time resolution and sensitivity, providing greater insight into their distribution in the atmosphere, dispersal mechanisms and potential soures. The WIBS-4A (Wideband Integrated Bioaerosol Sensor) detects fluorescent biological material in real-time associated with individual particles. It measures five properties: a) optical size via light scattering, b) fluorescent emissions in the wavelength range 310-400 following excitation by 280 nm light, c) fluorescent emissions in the wavelength range 420-650 following excitation by 280 nm light, d) fluorescent emissions in the wavelength range 420-650 following excitation by 370 nm light, and e) particle asymmetry factor based on intensities of forward scattered light onto a 4-element detector. Together, these properties aid the classification of sampled particles that contain biofluorophores such as tryptophan or NAD(P)H, which can be found in biological particles. Here we present results from a series of laboratory, ground- and aircraft-based measurements of biological particles using the WIBS-4A. The studies include airborne measurements over the United States, ground-based measurements at a coastal site, an urban site in the southeast US and a high alpine site, and laboratory measurements of a variety of biological and non-biological particles. Our analysis focused on both the characterization of the instrument response as well as an evaluation of its suitability for performing ambient measurements and potential artifacts. We

  4. Real-time Simultaneous Near-Infrared Fluorescence Imaging of Bile Duct and Arterial Anatomy

    PubMed Central

    Ashitate, Yoshitomo; Stockdale, Alan; Choi, Hak Soo; Laurence, Rita G.; Frangioni, John V.

    2011-01-01

    Background We hypothesized that two independent wavelengths of near-infrared (NIR) fluorescent light could be used to identify bile ducts and hepatic arteries simultaneously, and intraoperatively. Materials and Methods Three different combinations of 700 nm and 800 nm fluorescent contrast agents specific for bile ducts and arteries were injected into N = 10 35-kg female Yorkshire pigs intravenously. Combination 1 (C-1) was methylene blue (MB) for arterial imaging and indocyanine green (ICG) for bile duct imaging. Combination 2 (C-2) was ICG for arterial imaging and MB for bile duct imaging. Combination 3 (C-3) was a newly developed, zwitterionic NIR fluorophore ZW800-1 for arterial imaging and MB for bile duct imaging. Open and minimally invasive surgeries were imaged using the FLARE™ and m-FLARE™ systems, respectively. Results Although the desired bile duct and arterial anatomy could be imaged with contrast-to-background ratios (CBRs) ≥ 6 using all 3 combinations, each one differed significantly in terms of repetition and prolonged imaging. ICG injection resulted in high CBR of the liver and common bile duct (CBD) and prolonged imaging time (120 min) of the CBD (C-1). However, because ICG also resulted in high background of liver and CBD relative to arteries, ICG produced a lower arterial CBR (C-2) at some time points. C-3 provided the best overall performance, although C-2, which is clinically available, did enable effective laparoscopy. Conclusions We demonstrate that dual-channel NIR fluorescence imaging provides simultaneous, real-time, and high resolution identification of bile ducts and hepatic arteries during biliary tract surgery. PMID:21816414

  5. Technique for real-time tissue characterization based on scanning multispectral fluorescence lifetime spectroscopy (ms-TRFS)

    PubMed Central

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

    2015-01-01

    We report a novel technique for continuous acquisition, processing and display of fluorescence lifetimes enabling real-time tissue diagnosis through a single hand held or biopsy fiber-optic probe. A scanning multispectral time-resolved fluorescence spectroscopy (ms-TRFS) with self-adjustable photon detection range was developed to account for the dynamic changes of fluorescence intensity typically encountered in clinical application. A fast algorithm was implemented in the ms-TRFS software platform, providing up to 15 Hz continuous display of fluorescence lifetime values. Potential applications of this technique, including biopsy guidance, and surgical margins delineation were demonstrated in proof-of-concept experiments. Current results showed accurate display of fluorescence lifetimes values and discrimination of distinct fluorescence markers and tissue types in real-time (< 100 ms per data point). PMID:25798320

  6. Real time swallowing measurement system by using photometric stereo

    NASA Astrophysics Data System (ADS)

    Fujino, Masahiro; Kato, Kunihito; Mura, Emi; Nagai, Hajime

    2015-04-01

    In this paper, we propose a measurement system to evaluate the swallowing by estimating the movement of the thyroid cartilage. We developed a measurement system based on the vision sensor in order to achieve the noncontact and non-invasive sensor. The movement of the subject's thyroid cartilage is tracked by the three dimensional information of the surface of the skin measured by the photometric stereo. We constructed a camera system that uses near-IR light sources and three camera sensors. We conformed the effectiveness of the proposed system by experiments.

  7. Error Correction for Foot Clearance in Real-Time Measurement

    NASA Astrophysics Data System (ADS)

    Wahab, Y.; Bakar, N. A.; Mazalan, M.

    2014-04-01

    Mobility performance level, fall related injuries, unrevealed disease and aging stage can be detected through examination of gait pattern. The gait pattern is normally directly related to the lower limb performance condition in addition to other significant factors. For that reason, the foot is the most important part for gait analysis in-situ measurement system and thus directly affects the gait pattern. This paper reviews the development of ultrasonic system with error correction using inertial measurement unit for gait analysis in real life measurement of foot clearance. This paper begins with the related literature where the necessity of measurement is introduced. Follow by the methodology section, problem and solution. Next, this paper explains the experimental setup for the error correction using the proposed instrumentation, results and discussion. Finally, this paper shares the planned future works.

  8. Real-time measurement of engine oil economy

    SciTech Connect

    Butler, J.W.; Korniski, T.; Calvin, A.D.; Jary, E.H.

    1987-01-01

    A coulometric SO/sub 2/ monitor has been developed to measure SO/sub 2/ generated from combustion of S in oil to determine engine oil consumption. Sulfur-free fuel is used to eliminate background levels of SO/sub 2/. Addition of an SO/sub 2/ standard gas to the engine during test insures accurate normalization of sampling system flows and quantitative measurement of engine oil economy. Precision of the SO/sub 2/ microcoulometer technique was better than +-8%. The SO/sub 2/ microcoulometer is used during steady state engine operation, and may be used in determining oil consumption from individual cylinders. Existence of engine oil consumption via an aerosol mechanism is investigated and measured. Effects of engine operating temperature and positive crankcase ventilation (PCV) on engine oil economy are given.

  9. Real-Time Measurements of Sediment Modification by Large Macrofauna

    DTIC Science & Technology

    2006-01-01

    to organism behaviors. Nils Volkenborn ( Alfred Wegener Institute for Polar and Marine Research) and Lubos Polerecky (Microsensors Group, Max Planck...at the Alfred Wegener Institute for Polar and Marine Research. We combined geochemistry, physics, and behavior studies of Arenicola marina using...infauna have been excluded so that the biogenic hydraulic head causing advection can be measured. Nils Volkenborn and Karsten Reise ( Alfred

  10. Real-time diameter measurement using diffuse light

    NASA Astrophysics Data System (ADS)

    Luo, Xiaohe; Hui, Mei; Zhu, Qiudong; Wang, Shanshan

    2016-09-01

    A method for on-line rapid determination of the diameter of metallic cylinder is introduced in this paper. Under the radiation of diffuse light, there is a bright area close to the margin of metallic cylinder, and the method of this paper is based on the intensity distribution of the bright area. In this paper, with the radiation by a diffuse plane light with special shape, we present the relation expression of the distance between the peak point and the real edge of the cylinder and the distance between the diffuse light and the pinhole aperture of the camera. With the expression, the diameter of the cylinder to be measured can be calculated. In the experiments, monochromatic LED uniting with ground glass forms the diffuse light source, then the light irradiates the tested cylinder. After the cylinder, we use a lens with a front pinhole stop to choose the light into CMOS, then a computer is used to analyze images and export the measurement results. The measuring system using this method is very easily implemented, so it can realize the on-line rapid measurement. Experimental results are presented for six metallic cylinders with the diameter in 5 18mm range and roughness in Ra- 0.02um, and the precision reaches 3um.

  11. IN SITU Device for Real-Time Catalyst Deactivation Measurements

    SciTech Connect

    Fossil Energy Research

    2008-03-31

    SCR catalyst management has become an important operations and maintenance activity for coal-fired utility boilers in the United States. To facilitate this activity, a method to determine Catalyst Activity in situ is being developed. This report describes the methodology and presents the results of a two ozone season demonstration conducted at Alabama Power Company's Gorgas Unit 10 during the 2005 and 2006 ozone seasons. The results showed that the in situ measurements are in good agreement with the laboratory measurements and the technique has some advantages over the traditional laboratory method of determining Catalyst Activity and Reactor Potential. SCR Performance is determined by the overall Reactor Potential (the product of the Catalyst Activity and the available surface area per unit of flue gas). The in situ approach provides a direct measurement of Reactor Potential under actual operating conditions, whereas laboratory measurements of Catalyst Activity need to be coupled with estimates of catalyst pluggage and flue gas flowrate in order to assess Reactor Potential. The project also showed that the in situ activity results can easily be integrated into catalyst management software to aid in making informed catalyst decisions.

  12. Using real time process measurements to reduce catheter related bloodstream infections in the intensive care unit

    PubMed Central

    Wall, R; Ely, E; Elasy, T; Dittus, R; Foss, J; Wilkerson, K; Speroff, T

    2005-01-01

    

Problem: Measuring a process of care in real time is essential for continuous quality improvement (CQI). Our inability to measure the process of central venous catheter (CVC) care in real time prevented CQI efforts aimed at reducing catheter related bloodstream infections (CR-BSIs) from these devices. Design: A system was developed for measuring the process of CVC care in real time. We used these new process measurements to continuously monitor the system, guide CQI activities, and deliver performance feedback to providers. Setting: Adult medical intensive care unit (MICU). Key measures for improvement: Measured process of CVC care in real time; CR-BSI rate and time between CR-BSI events; and performance feedback to staff. Strategies for change: An interdisciplinary team developed a standardized, user friendly nursing checklist for CVC insertion. Infection control practitioners scanned the completed checklists into a computerized database, thereby generating real time measurements for the process of CVC insertion. Armed with these new process measurements, the team optimized the impact of a multifaceted intervention aimed at reducing CR-BSIs. Effects of change: The new checklist immediately provided real time measurements for the process of CVC insertion. These process measures allowed the team to directly monitor adherence to evidence-based guidelines. Through continuous process measurement, the team successfully overcame barriers to change, reduced the CR-BSI rate, and improved patient safety. Two years after the introduction of the checklist the CR-BSI rate remained at a historic low. Lessons learnt: Measuring the process of CVC care in real time is feasible in the ICU. When trying to improve care, real time process measurements are an excellent tool for overcoming barriers to change and enhancing the sustainability of efforts. To continually improve patient safety, healthcare organizations should continually measure their key clinical processes in real

  13. Adaptive, real-time hypoxia measurements using an autonomous boat

    NASA Astrophysics Data System (ADS)

    Kerkez, B.; Wong, B. P.; Balzano, L.; Lipor, J.; Scavia, D.

    2015-12-01

    We present an autonomous system to measure hypoxia at high spatial resolutions. The approach combines a robotic boat, cloud hosted data services, and a suite of adaptive sampling algorithms to minimize the number of samples required to delineate hypoxic extents. The boat lowers sensors into the water column to provide depth profiles of temperature and oxygen concentrations. An adaptive path-planning algorithm continuously analyzes the in-situ observations and directs the boat to its next measurement location. This significantly reduces number of samples compared to a gridded sampling approach, while simultaneously improving the certainty with which the hypoxic regions are delineated. The method has been evaluated on small lakes throughout Michigan and shows significant promise to scale to the Great Lakes, where hypoxia is common occurrence that adversely affects various stakeholder and ecosystems.

  14. Real Time Measurement of Host Bioenergetics During Mycobacterium Tuberculosis Infection

    DTIC Science & Technology

    2014-09-01

    treated cultures and the basal respiration of the bacilli measured. The results (Figure 6) show that BDQ (at both concentrations) increases the basal... respiration (as seen previously) when compared to an untreated control, after which basal respiration drops to almost zero at day 1 and zero at day 6...after drug treatment in the case of 300x MIC. The basal respiration of the bacilli treated with 30x MIC BDQ stays elevated for longer and does not

  15. Automated real-time measurement of chemotactic cell motility.

    PubMed

    Hadjout, N; Laevsky, G; Knecht, D A; Lynes, M A

    2001-11-01

    We have developed a novel method, (ECIS/taxis), for monitoring cell movement in response to chemotactic and chemokinetic factors. In this system, cells migrate in an under-agarose environment, and their positions are monitored using the electric cell-substrate impedance sensor technology to measure the impedance change at a target electrode, that is lithographed onto the substrate, as the cells arrive at the target. In the studies reported here, Dictyostelium discoideum was used as a prototypical, motile eukaryotic cell. Using the ECIS/taxis system, the arrival of cells at the target electrode was proportional to the dose offolate used to stimulate the cells and could be assessed by changes in resistance at the electrode. ECIS/taxis was readily able to distinguish between wild-type cells and a mutant that is deficient in its chemotactic response. Finally, we have shown that an agent that interferes with chemotactic motility leads to the delayed arrival of cells at the target electrode. The multi-well assay configuration allows for simultaneous automated screening of many samples for chemotactic or anti-chemotactic activity. This assay system is compatible with measurements of mammalian cell movement and should be valuable in the assessment of both agonists and antagonists of cell movement.

  16. Rapid detection of group B streptococcus and Escherichia coli in amniotic fluid using real-time fluorescent PCR.

    PubMed

    Straka, Michele; Dela Cruz, Wifred; Blackmon, Camille; Johnson, Oswald; Stassen, Sara; Streitman, David; Golden, Stephen; Stamilio, David

    2004-01-01

    To establish reliability and validity of real-time fluorescent PCR for early detection of bacterial invasion of the amniotic cavity. Amniotic fluid samples from 40 patients undergoing mid-trimester genetic amniocentesis were incubated for 6 h at 37 degrees C and were cultured on media specific for group B streptococcus (GBS) and E. coli. Concurrently, samples were analyzed with real-time fluorescent PCR (Roche LightCycler) using DNA primers and probes designed to detect the CAMP factor encoding cfb gene and uidA gene of GBS and E. coli, respectively. For positive control and to simulate amniotic fluid colonization, 104 cfu/ml of GBS and E. coli were inoculated on sterile amniotic fluid and incubated for 6 h. Bacterial genomic DNA for the two organisms was extracted and purified via the two-step precipitation method using a commercial kit. The real-time PCR assays were also tested against 25 non-GBS and non-E. coli bacterial species. The lower limit of detection for each pathogen was established using serial dilution of bacterial genomic DNA. All patient samples were negative for evidence of GBS and E. coli with both culture and real-time PCR methods. Amniotic fluid samples inoculated with GBS and E. coli were positive with real-time PCR whereas the 25 bacterial species other than GBS or E. coli tested negative with the assay. Average total sample processing time including the pre-enrichment step was 7 h 40 min. The average cost for DNA extraction and PCR testing was 8.50 dollars per test. Real-time fluorescent PCR is a valid and reliable method for detection of specific pathogens in amniotic fluid. This technique is sensitive for low inoculation levels. Real-time fluorescent PCR has potential to impact clinical management as a rapid, reliable detection method for GBS and E. coli in chorioamnionitis.

  17. GPU accelerated real-time confocal fluorescence lifetime imaging microscopy (FLIM) based on the analog mean-delay (AMD) method

    PubMed Central

    Kim, Byungyeon; Park, Byungjun; Lee, Seungrag; Won, Youngjae

    2016-01-01

    We demonstrated GPU accelerated real-time confocal fluorescence lifetime imaging microscopy (FLIM) based on the analog mean-delay (AMD) method. Our algorithm was verified for various fluorescence lifetimes and photon numbers. The GPU processing time was faster than the physical scanning time for images up to 800 × 800, and more than 149 times faster than a single core CPU. The frame rate of our system was demonstrated to be 13 fps for a 200 × 200 pixel image when observing maize vascular tissue. This system can be utilized for observing dynamic biological reactions, medical diagnosis, and real-time industrial inspection. PMID:28018724

  18. Fluorescence interference contrast based approach to study real time interaction of melittin with plasma membranes

    NASA Astrophysics Data System (ADS)

    Gupta, Sharad; Gui, Dong; Zandi, Roya; Gill, Sarjeet; Mohideen, Umar

    2014-03-01

    Melittin is an anti-bacterial and hemolytic toxic peptide found in bee venom. Cell lysis behavior of peptides has been widely investigated, but the exact interaction mechanism of lytic peptides with lipid membranes and its constituents has not been understood completely. In this paper we study the melittin interaction with lipid plasma membranes in real time using non-invasive and non-contact fluorescence interference contrast microscopy (FLIC). Particularly the interaction of melittin with plasma membranes was studied in a controlled molecular environment, where these plasma membrane were composed of saturated lipid, 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and unsaturated lipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC) with and without cholesterol. We found out that melittin starts to form nanometer size pores in the plasma membranes shortly after interacting with membranes. But the addition of cholesterol in plasma membrane slows down the pore formation process. Our results show that inclusion of cholesterol to the plasma membranes make them more resilient towards pore formation and lysis of membrane.

  19. A real-time fluorescence polarization activity assay to screen for inhibitors of bacterial ribonuclease P

    PubMed Central

    Liu, Xin; Chen, Yu; Fierke, Carol A.

    2014-01-01

    Ribonuclease P (RNase P) is an essential endonuclease that catalyzes the 5′ end maturation of precursor tRNA (pre-tRNA). Bacterial RNase P is an attractive potential antibacterial target because it is essential for cell survival and has a distinct subunit composition compared to the eukaryal counterparts. To accelerate both structure-function studies and discovery of inhibitors of RNase P, we developed the first real-time RNase P activity assay using fluorescence polarization/anisotropy (FP/FA) with a 5′ end fluorescein-labeled pre-tRNAAsp substrate. This FP/FA assay also detects binding of small molecules to pre-tRNA. Neomycin B and kanamycin B bind to pre-tRNAAsp with a Kd value that is comparable to their IC50 value for inhibition of RNase P, suggesting that binding of these antibiotics to the pre-tRNA substrate contributes to the inhibitory activity. This assay was optimized for high-throughput screening (HTS) to identify specific inhibitors of RNase P from a 2880 compound library. A natural product derivative, iriginol hexaacetate, was identified as a new inhibitor of Bacillus subtilis RNase P. The FP/FA methodology and inhibitors reported here will further our understanding of RNase P molecular recognition and facilitate discovery of antibacterial compounds that target RNase P. PMID:25249623

  20. Robotic duodenopancreatectomy assisted with augmented reality and real-time fluorescence guidance.

    PubMed

    Pessaux, Patrick; Diana, Michele; Soler, Luc; Piardi, Tullio; Mutter, Didier; Marescaux, Jacques

    2014-08-01

    The minimally invasive surgeon cannot use 'sense of touch' to orientate surgical resection, identifying important structures (vessels, tumors, etc.) by manual palpation. Robotic research has provided technology to facilitate laparoscopic surgery; however, robotics has yet to solve the lack of tactile feedback inherent to keyhole surgery. Misinterpretation of the vascular supply and tumor location may increase the risk of intraoperative bleeding and worsen dissection with positive resection margins. Augmented reality (AR) consists of the fusion of synthetic computer-generated images (three-dimensional virtual model) obtained from medical imaging preoperative work-up and real-time patient images with the aim of visualizing unapparent anatomical details. In this article, we review the most common modalities used to achieve surgical navigation through AR, along with a report of a case of robotic duodenopancreatectomy using AR guidance complemented with the use of fluorescence guidance. The presentation of this complex and high-technology case of robotic duodenopancreatectomy, and the overview of current technology that has made it possible to use AR in the operating room, highlights the needs for further evolution and the windows of opportunity to create a new paradigm in surgical practice.

  1. An inexpensive microslab gel DNA electrophoresis system with real-time fluorescence detection.

    PubMed

    Chen, Xiaojia; Ugaz, Victor M

    2006-02-01

    In this paper, we describe the construction of a simple yet powerful gel electrophoresis apparatus that can be used to perform size-selective separations of DNA fragments in virtually any laboratory. This system employs a microslab gel format with a novel gel casting technique that eliminates the need for delicate combs to define sample loading wells. The compact size of the microslab gel format allows rapid separations to be performed at low voltages using submicroliter sample volumes. Real time fluorescence detection of the migrating DNA fragments is accomplished using an inexpensive digital microscope that directly connects to any PC with a USB interface. The microscope is readily adaptable for this application by replacing its white light source with a blue light-emitting diode (LED) and adding an appropriate emission filter. Both polyacrylamide and agarose gels can be used as separation matrices. Separation performance was characterized using standard dsDNA ladders, and correct sizing of a 191 bp PCR product was achieved in 15 min. The low cost and simplicity of this system makes it ideally suited for use in a variety of laboratory and educational settings.

  2. A fluorescence spectroscopy assay for real-time monitoring of enzyme immobilization into mesoporous silica particles.

    PubMed

    Nabavi Zadeh, Pegah S; Mallak, Kassam Abdel; Carlsson, Nils; Åkerman, Björn

    2015-05-01

    Mesoporous silica particles are used as support material for immobilization of enzymes. Here we investigated a fluorescence-based assay for real-time monitoring of the immobilization of lipase, bovine serum albumin, and glucose oxidase into micrometer-sized mesoporous silica particles. The proteins are labeled with the dye epicocconone, and the interaction with the particles is observed as an increase in emission intensity of the protein-dye conjugates that can be quantified if correcting for a comparatively slow photobleaching. The immobilization occurs in tens of minutes to hours depending on particle concentration and type of protein. In the limit of excess particles over proteins, the formation of the particle-protein complexes can be described by a single exponential growth for all three investigated proteins, and the fitted pseudo-first-order rate constant increases linearly with particle concentration for each protein type. The derived second-order rate constant k varies with the protein hydrodynamic radius according to k∼RH(-4.70±0.01), indicating that the rate-limiting step at high particle concentrations is not the diffusional encounter between proteins and particles but rather the entry into the pores, consistent with the hydrodynamic radii of the three proteins being smaller but comparable to the pore radius of the particles.

  3. Hilbert phase dynamometry (HPD) for real-time measurement of cell generated forces (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sridharan, Shamira; Li, Yanfen; Bhaduri, Basanta; Majeed, Hassaan; Dupenloup, Paul; Levine, Alex; Kilian, Kristopher A.; Popescu, Gabriel

    2016-03-01

    Traction force microscopy is the most widely used technique for studying the forces exerted by cells on deformable substrates. However, the method is computationally intense and cells have to be detached from the substrate prior to measuring the displacement map. We have developed a new method, referred to as Hilbert phase dynamometry (HPD), which yields real-time force fields and, simultaneously, cell dry mass and growth information. HPD operates by imaging cells on a deformable substrate that is patterned with a grid of fluorescent proteins. A Hilbert transform is used to extract the phase map associated with the grid deformation, which provides the displacement field. By combining this information with substrate stiffness, an elasticity model was developed to measure forces exerted by cells with high spatial resolution. In our study, we prepared 10kPa gels and them with a 2-D grid of FITC-conjugated fibrinogen/fibronectin mixture, an extracellular matrix protein to which cells adhere. We cultured undifferentiated mesenchymal stem cells (MSC), and MSCs that were in the process of undergoing adipogenesis and osteogenesis. The cells were measured over the course of 24 hours using Spatial Light Interference Microscopy (SLIM) and wide-field epi-fluorescence microscopy allowing us to simultaneously measure cell growth and the forces exerted by the cells on the substrate.

  4. Real-Time Intraoperative Near-Infrared Fluorescence Identification of the Extrahepatic Bile Ducts using Clinically-Available Contrast Agents

    PubMed Central

    Matsui, Aya; Tanaka, Eiichi; Choi, Hak Soo; Winer, Joshua H.; Kianzad, Vida; Gioux, Sylvain; Laurence, Rita G.; Frangioni, John V.

    2009-01-01

    Background Iatrogenic bile duct injuries are serious complications with patient morbidity. We hypothesized that the invisible near-infrared (NIR) fluorescence properties of methylene blue (MB) and indocyanine green (ICG) could be exploited for real-time, intraoperative imaging of the extrahepatic bile ducts during open and laparoscopic surgeries. Methods 2.0 mg/kg of MB and 0.05 mg/kg of ICG were intravenously injected into 35-kg female Yorkshire pigs and the extrahepatic bile ducts imaged over time using either the FLARE™ image-guided surgery system (open surgery) or a custom NIR fluorescence laparoscopy system. Surgical anatomy was confirmed using x-ray cholangiography. Contrast-to-background ratio (CBR), contrast-to-liver ratio (CLR), and chemical concentrations in the cystic duct (CD) and common bile duct (CBD) were measured, and the performance of each agent quantified. Results Using NIR fluorescence of MB, the CD and CBD could be identified with good sensitivity (CBR and CLR ≥ 4), during both open and laparoscopic surgeries, from 10 to 120 min post-injection. Functional impairment of the ducts, including constriction and injury were immediately identifiable. Using NIR fluorescence of ICG, extrahepatic bile ducts did not become visible until 90 min post-injection due to strong residual liver retention, however, between 90 to 240 min, ICG provided exquisitely high sensitivity for both CD and CBD, with CBR ≥ 8 and CLR ≥ 4. Conclusions We demonstrate that two clinically available NIR fluorophores, MB fluorescing at 700 nm and ICG fluorescing at 800 nm, provide sensitive, prolonged identification of the extrahepatic bile ducts and assessment of their functional status. PMID:20117813

  5. Laser-induced radiation microbeam technology and simultaneous real-time fluorescence imaging in live cells.

    PubMed

    Botchway, Stanley W; Reynolds, Pamela; Parker, Anthony W; O'Neill, Peter

    2012-01-01

    The use of nano- and microbeam techniques to induce and identify subcellular localized energy deposition within a region of a living cell provides a means to investigate the effects of low radiation doses. Particularly within the nucleus where the propagation and processing of deoxyribonucleic acid (DNA) damage (and repair) in both targeted and nontargeted cells, the latter being able to study cell-cell (bystander) effects. We have pioneered a near infrared (NIR) femtosecond laser microbeam to mimic ionizing radiation through multiphoton absorption within a 3D femtoliter volume of a highly focused Gaussian laser beam. The novel optical microbeam mimics both complex ionizing and UV-radiation-type cell damage including double strand breaks (DSBs). Using the microbeam technology, we have been able to investigate the formation of DNA DSB and subsequent recruitment of repair proteins to the submicrometer size site of damage introduced in viable cells. The use of a phosphorylated H2AX (γ-H2AX a marker for DSBs, visualized by immunofluorescent staining) and real-time imaging of fluorescently labeling proteins, the dynamics of recruitment of repair proteins in viable mammalian cells can be observed. Here we show the recruitment of ATM, p53 binding protein 1 (53BP1), and RAD51, an integral protein of the homologous recombination process in the DNA repair pathway and Ku-80-GFP involved in the nonhomologous end joining (NHEJ) pathway as exemplar repair process to show differences in the repair kinetics of DNA DSBs. The laser NIR multiphoton microbeam technology shows persistent DSBs at later times post laser irradiation which are indicative of DSBs arising at replication presumably from UV photoproducts or clustered damage containing single strand breaks (SSBs) that are also observed. Effects of the cell cycle may also be investigated in real time. Postirradiation and fixed cells studies show that in G1 cells a fraction of multiphoton laser-induced DSBs is persistent for >6h

  6. Fluorescent Single-Stranded DNA Binding Protein as a Probe for Sensitive, Real-Time Assays of Helicase Activity

    PubMed Central

    Dillingham, Mark S.; Tibbles, Katherine L.; Hunter, Jackie L.; Bell, Jason C.; Kowalczykowski, Stephen C.; Webb, Martin R.

    2008-01-01

    The formation and maintenance of single-stranded DNA (ssDNA) are essential parts of many processes involving DNA. For example, strand separation of double-stranded DNA (dsDNA) is catalyzed by helicases, and this exposure of the bases on the DNA allows further processing, such as replication, recombination, or repair. Assays of helicase activity and probes for their mechanism are essential for understanding related biological processes. Here we describe the development and use of a fluorescent probe to measure ssDNA formation specifically and in real time, with high sensitivity and time resolution. The reagentless biosensor is based on the ssDNA binding protein (SSB) from Escherichia coli, labeled at a specific site with a coumarin fluorophore. Its use in the study of DNA manipulations involving ssDNA intermediates is demonstrated in assays for DNA unwinding, catalyzed by DNA helicases. PMID:18599625

  7. Real-time measurements to characterize dynamics of emulsion interface during simulated intestinal digestion.

    PubMed

    Pan, Yuanjie; Nitin, N

    2016-05-01

    Efficient delivery of bioactives remains a critical challenge due to their limited bioavailability and solubility. While many encapsulation systems are designed to modulate the digestion and release of bioactives within the human gastrointestinal tract, there is limited understanding of how engineered structures influence the delivery of bioactives. The objective of this study was to develop a real-time quantitative method to measure structural changes in emulsion interface during simulated intestinal digestion and to correlate these changes with the release of free fatty acids (FFAs). Fluorescence resonant energy transfer (FRET) was used for rapid in-situ measurement of the structural changes in emulsion interface during simulated intestinal digestion. By using FRET, changes in the intermolecular spacing between the two different fluorescent probes labeled emulsifier were characterized. Changes in FRET measurements were compared with the release of FFAs. The results showed that bile salts and pancreatic lipase interacted immediately with the emulsion droplets and disrupted the emulsion interface as evidenced by reduction in FRET efficacy compared to the control. Similarly, a significant amount of FFAs was released during digestion. Moreover, addition of a second layer of polymers at emulsion interface decreased the extent of interface disruption by bile salts and pancreatic lipase and impacted the amount or rate of FFA release during digestion. These results were consistent with the lower donor/acceptor ratio of the labeled probes from the FRET result. Overall, this study provides a novel approach to analyze the dynamics of emulsion interface during digestion and their relationship with the release of FFAs.

  8. A real-time single sperm tracking, laser trapping, and ratiometric fluorescent imaging system

    NASA Astrophysics Data System (ADS)

    Shi, Linda Z.; Botvinick, Elliot L.; Nascimento, Jaclyn; Chandsawangbhuwana, Charlie; Berns, Michael W.

    2006-08-01

    Sperm cells from a domestic dog were treated with oxacarbocyanine DiOC II(3), a ratiometrically-encoded membrane potential fluorescent probe in order to monitor the mitochondria stored in an individual sperm's midpiece. This dye normally emits a red fluorescence near 610 nm as well as a green fluorescence near 515 nm. The ratio of red to green fluorescence provides a substantially accurate and precise measurement of sperm midpiece membrane potential. A two-level computer system has been developed to quantify the motility and energetics of sperm using video rate tracking, automated laser trapping (done by the upper-level system) and fluorescent imaging (done by the lower-level system). The communication between these two systems is achieved by a networked gigabit TCP/IP cat5e crossover connection. This allows for the curvilinear velocity (VCL) and ratio of the red to green fluorescent images of individual sperm to be written to the hard drive at video rates. This two-level automatic system has increased experimental throughput over our previous single-level system (Mei et al., 2005) by an order of magnitude.

  9. SNSMIL, a real-time single molecule identification and localization algorithm for super-resolution fluorescence microscopy

    PubMed Central

    Tang, Yunqing; Dai, Luru; Zhang, Xiaoming; Li, Junbai; Hendriks, Johnny; Fan, Xiaoming; Gruteser, Nadine; Meisenberg, Annika; Baumann, Arnd; Katranidis, Alexandros; Gensch, Thomas

    2015-01-01

    Single molecule localization based super-resolution fluorescence microscopy offers significantly higher spatial resolution than predicted by Abbe’s resolution limit for far field optical microscopy. Such super-resolution images are reconstructed from wide-field or total internal reflection single molecule fluorescence recordings. Discrimination between emission of single fluorescent molecules and background noise fluctuations remains a great challenge in current data analysis. Here we present a real-time, and robust single molecule identification and localization algorithm, SNSMIL (Shot Noise based Single Molecule Identification and Localization). This algorithm is based on the intrinsic nature of noise, i.e., its Poisson or shot noise characteristics and a new identification criterion, QSNSMIL, is defined. SNSMIL improves the identification accuracy of single fluorescent molecules in experimental or simulated datasets with high and inhomogeneous background. The implementation of SNSMIL relies on a graphics processing unit (GPU), making real-time analysis feasible as shown for real experimental and simulated datasets. PMID:26098742

  10. Real-time monitoring of bacterial and organic pollution in a water stream by fluorescence depletion spectroscopy

    NASA Astrophysics Data System (ADS)

    Gaulier, Geoffrey; Staedler, Davide; Sousa, Gustavo; Bonacina, Luigi; Wolf, Jean-Pierre

    2017-02-01

    We demonstrate an approach for a real-time, consumable-free optical system operating on a liquid jet which can be easily derived from the water distribution infrastructure. We apply a pump-probe scheme based on the acquisition and nanosecond manipulation of UV-excited fluorescence to increase the selective identification of bacterial against organic pollutants in water.

  11. Real-time measurement with a fiber optical surface plasmon resonance sensor for biochemical interaction analysis

    NASA Astrophysics Data System (ADS)

    Tan, Zhixin; Li, Xuejin; Chen, Yuzhi; Fan, Ping

    2013-08-01

    In this paper we report a fiber optical sensor system based on surface plasmon resonance (SPR) with real-time response for biochemical interaction analysis. The fiber sensor is constructed from a multi-mode fiber with plastic cladding. To facilitate the measurement, a software program is developed which integrates the data acquisition and processing for real-time feedback. Polynomial fitting is implemented to smooth out the noise in the transmission ratio and a spectral resolution of 0.2 nm is achieved. Ethyl alcohol and water mixtures with different concentrations are measured to demonstrate the system's real-time capability. This work is essential for the development of a compact, real-time fiber SPR biosensor.

  12. AUTOMATED CONTROL AND REAL-TIME DATA PROCESSING OF WIRE SCANNER/HALO SCRAPER MEASUREMENTS

    SciTech Connect

    L.A. DAY; J.D. GILPATRICK; ET AL

    2001-06-01

    The Low-Energy Demonstration Accelerator (LEDA), assembled and operating at Los Alamos National Laboratory, provides the platform for obtaining measurements of high-power proton beam-halo formation. Control system software and hardware have been integrated and customized to enable the production of real-time beam-halo profiles. The Experimental Physics and Industrial Control System (EPICS) hosted on a VXI platform, Interactive Data Language (IDL) programs hosted on UNIX platforms, and LabVIEW (LV) Virtual Instruments hosted on a PC platform have been integrated and customized to provide real-time, synchronous motor control, data acquisition, and data analysis of data acquired through specialized DSP instrumentation. These modules communicate through EPICS Channel Access (CA) communication protocol extensions to control and manage execution flow ensuring synchronous data acquisition and real-time processing of measurement data. This paper describes the software integration and management scheme implemented to produce these real-time beam profiles.

  13. Real-time hyperspectral fluorescence imaging of pancreatic β-cell dynamics with the image mapping spectrometer

    PubMed Central

    Elliott, Amicia D.; Gao, Liang; Ustione, Alessandro; Bedard, Noah; Kester, Robert; Piston, David W.; Tkaczyk, Tomasz S.

    2012-01-01

    Summary The development of multi-colored fluorescent proteins, nanocrystals and organic fluorophores, along with the resulting engineered biosensors, has revolutionized the study of protein localization and dynamics in living cells. Hyperspectral imaging has proven to be a useful approach for such studies, but this technique is often limited by low signal and insufficient temporal resolution. Here, we present an implementation of a snapshot hyperspectral imaging device, the image mapping spectrometer (IMS), which acquires full spectral information simultaneously from each pixel in the field without scanning. The IMS is capable of real-time signal capture from multiple fluorophores with high collection efficiency (∼65%) and image acquisition rate (up to 7.2 fps). To demonstrate the capabilities of the IMS in cellular applications, we have combined fluorescent protein (FP)-FRET and [Ca2+]i biosensors to measure simultaneously intracellular cAMP and [Ca2+]i signaling in pancreatic β-cells. Additionally, we have compared quantitatively the IMS detection efficiency with a laser-scanning confocal microscope. PMID:22854044

  14. Real-time hyperspectral fluorescence imaging of pancreatic β-cell dynamics with the image mapping spectrometer.

    PubMed

    Elliott, Amicia D; Gao, Liang; Ustione, Alessandro; Bedard, Noah; Kester, Robert; Piston, David W; Tkaczyk, Tomasz S

    2012-10-15

    The development of multi-colored fluorescent proteins, nanocrystals and organic fluorophores, along with the resulting engineered biosensors, has revolutionized the study of protein localization and dynamics in living cells. Hyperspectral imaging has proven to be a useful approach for such studies, but this technique is often limited by low signal and insufficient temporal resolution. Here, we present an implementation of a snapshot hyperspectral imaging device, the image mapping spectrometer (IMS), which acquires full spectral information simultaneously from each pixel in the field without scanning. The IMS is capable of real-time signal capture from multiple fluorophores with high collection efficiency (∼65%) and image acquisition rate (up to 7.2 fps). To demonstrate the capabilities of the IMS in cellular applications, we have combined fluorescent protein (FP)-FRET and [Ca(2+)](i) biosensors to measure simultaneously intracellular cAMP and [Ca(2+)](i) signaling in pancreatic β-cells. Additionally, we have compared quantitatively the IMS detection efficiency with a laser-scanning confocal microscope.

  15. Glowing clay: Real time tracing using a suite of novel clay based fluorescent tracers

    NASA Astrophysics Data System (ADS)

    Hardy, Robert; Quinton, John; Pates, Jackie; Coogan, Mike

    2015-04-01

    Clay is one of the most mobile fractions of soil due to its small particle size. It is also known to sorb many chemicals, such as nutrients (notably phosphorus), agrochemicals and heavy metals. The movement of clay is therefore linked with the transport and fate of these substances. A novel fluorescent clay tracing suite has been produced, together with an imaging technique. This suite consists of qualitative clay tracers, using rhodamine based fluorophores, and quantitative clay tracers, using metal based fluorophores. Efforts have also been made to allow integration of commercially available tracers, which are silt and sand sized. The clay tracers exploit the high affinity that montmorillonite has for Rhodamine B and Ru(bpy)3. This allows for an extremely thin layer of the fluorophore to be sorbed onto the clay's surface, in much that same way as materials in the natural environment will bind to clay. The tracer that is produced retains key chemical and physical properties of clay, such as size, shape and density. The retention of these micro-properties results in the retention of macro-properties, such as tendency to aggregate and cracking on drying. Imaging techniques have been developed to analyse these tracers. The imaging system uses diffused laser light to excite the tracer and a modified DSLR camera to image the soil surface. The images have been compiled into a time lapse video showing the movement of clay over the course of a rainfall event. This is the first time that the quantitative movement of clay has been recorded over a soil surface in real time. 4D data can be extracted from the images allowing the spatial location and intensity of tracer to be monitored over time, with mm precision and on the timescale of seconds. As the system can also work with a commercial tracer it is possible to investigate the movement of particles of almost any size and over a range of scales from soil box to hillside. This allows users to access this technique without

  16. Potential of real-time measurement of GFP-fusion proteins.

    PubMed

    Jones, Jo J; Bridges, Angela M; Fosberry, Andrew P; Gardner, Sharmila; Lowers, Robert R; Newby, Rachel R; James, Philip J; Hall, Richard M; Jenkins, Owen

    2004-04-08

    Building on the basic design concepts of Randers-Eichhorn [Biotechnol. Bioeng. 55 (1997) 921], an on-line, real-time robust, steam sterilisable optical sensor for monitoring green fluorescent protein (GFP) has been developed. A general cloning vector for fusion expression proteins was constructed, allowing expression of both GFP and the target protein as a fusion. Cultivations were carried out at the 20l scale with the signal from the sensor being relayed directly to the control system of the bioreactors. The production of GFP was then measured on-line, the signal was interfaced directly with other controlling parameters, thereby allowing the microbial process to be controlled directly based on recombinant protein expression. A positive expression correlation between on-line and off-line data was obtained. Protein accretion measured off-line was quantified using both LC-MS and plate reader assays. The potential of such a sensor for many aspects of process development is considerable and we have developed a working system which allows the optimisation of production conditions, for example, linking pH control directly to the fusion protein. Results are also presented that illustrate GFP does not alter the cultivation characteristics of the target protein when compared to the native construct. Whether GFP expressed as a fusion influences the solubility of the target protein is also discussed.

  17. Method and apparatus for real-time measurement of fuel gas compositions and heating values

    DOEpatents

    Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

    2016-03-22

    An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

  18. Real-time remote detection and measurement for airborne imaging spectroscopy: a case study with methane

    NASA Astrophysics Data System (ADS)

    Thompson, D. R.; Leifer, I.; Bovensmann, H.; Eastwood, M.; Fladeland, M.; Frankenberg, C.; Gerilowski, K.; Green, R. O.; Kratwurst, S.; Krings, T.; Luna, B.; Thorpe, A. K.

    2015-06-01

    Localized anthropogenic sources of atmospheric CH4 are highly uncertain and temporally variable. Airborne remote measurement is an effective method to detect and quantify these emissions. In a campaign context, the science yield can be dramatically increased by real-time retrievals that allow operators to coordinate multiple measurements of the most active areas. This can improve science outcomes for both single- and multiple-platform missions. We describe a case study of the NASA/ESA CO2 and Methane Experiment (COMEX) campaign in California during June and August/September 2014. COMEX was a multi-platform campaign to measure CH4 plumes released from anthropogenic sources including oil and gas infrastructure. We discuss principles for real-time spectral signature detection and measurement, and report performance on the NASA Next Generation Airborne Visible Infrared Spectrometer (AVIRIS-NG). AVIRIS-NG successfully detected CH4 plumes in real-time at Gb s-1 data rates, characterizing fugitive releases in concert with other in situ and remote instruments. The teams used these real-time CH4 detections to coordinate measurements across multiple platforms, including airborne in situ, airborne non-imaging remote sensing, and ground-based in situ instruments. To our knowledge this is the first reported use of real-time trace gas signature detection in an airborne science campaign, and presages many future applications.

  19. [Detection of human enteroviruses with real-time PCR assay using TaqMan fluorescent probe].

    PubMed

    Leś, Katarzyna; Przybylski, Maciej; Dzieciatkowski, Tomasz; Młynarczyk, Grazyna

    2010-01-01

    Infections with human enteroviruses are common worldwide and cause a wide range of signs and symptoms. Nowadays in current diagnostics procedures older virological methods, such virus isolation in a cell cultures and seroneutralisation assay, are replaced with molecular biology tests. The aim of the study was development of real-time PCR assay for detection of human adenoviruses. DNA isolated from MK2 cell line infected with nineteen different enterovirus strains was used for development of a qualitative real-time PCR assay using primers targeting a conserved region of the 5'UTR region and a specific TaqMan probe. The analytical sensitivity of real-time PCR assay was tested using serial dilutions of Coxackie A9 cDNA in range between 10 degrees and 10(-8). For comparison typical end-point detected RT-PCR for enterovirus detection with the same cDNA dilutions was made. The sensitivity of novel method was about ten thousand-fold higher than older one. The conclusion is that real-time PCR is very advisable in diagnostics of diseases caused with enteroviruses. The high level of sensitivity, specificity, accuracy, and rapidity provided by this assay are favorable for the use in the detection of enteroviral RNA in clinical specimens, especially from neuroinfections.

  20. Bioinspired fluorescent dipeptide nanoparticles for targeted cancer cell imaging and real-time monitoring of drug release.

    PubMed

    Fan, Zhen; Sun, Leming; Huang, Yujian; Wang, Yongzhong; Zhang, Mingjun

    2016-04-01

    Peptide nanostructures are biodegradable and are suitable for many biomedical applications. However, to be useful imaging probes, the limited intrinsic optical properties of peptides must be overcome. Here we show the formation of tryptophan-phenylalanine dipeptide nanoparticles (DNPs) that can shift the peptide's intrinsic fluorescent signal from the ultraviolet to the visible range. The visible emission signal allows the DNPs to act as imaging and sensing probes. The peptide design is inspired by the red shift seen in the yellow fluorescent protein that results from π-π stacking and by the enhanced fluorescence intensity seen in the green fluorescent protein mutant, BFPms1, which results from the structure rigidification by Zn(II). We show that DNPs are photostable, biocompatible and have a narrow emission bandwidth and visible fluorescence properties. DNPs functionalized with the MUC1 aptamer and doxorubicin can target cancer cells and can be used to image and monitor drug release in real time.

  1. Bioinspired fluorescent dipeptide nanoparticles for targeted cancer cell imaging and real-time monitoring of drug release

    NASA Astrophysics Data System (ADS)

    Fan, Zhen; Sun, Leming; Huang, Yujian; Wang, Yongzhong; Zhang, Mingjun

    2016-04-01

    Peptide nanostructures are biodegradable and are suitable for many biomedical applications. However, to be useful imaging probes, the limited intrinsic optical properties of peptides must be overcome. Here we show the formation of tryptophan-phenylalanine dipeptide nanoparticles (DNPs) that can shift the peptide's intrinsic fluorescent signal from the ultraviolet to the visible range. The visible emission signal allows the DNPs to act as imaging and sensing probes. The peptide design is inspired by the red shift seen in the yellow fluorescent protein that results from π-π stacking and by the enhanced fluorescence intensity seen in the green fluorescent protein mutant, BFPms1, which results from the structure rigidification by Zn(II). We show that DNPs are photostable, biocompatible and have a narrow emission bandwidth and visible fluorescence properties. DNPs functionalized with the MUC1 aptamer and doxorubicin can target cancer cells and can be used to image and monitor drug release in real time.

  2. Real time two-dimensional spatial distribution measurement method of electron temperature and plasma density

    NASA Astrophysics Data System (ADS)

    Kim, Young Cheol; Jang, Sung Ho; Kim, Gun Ho; Chung, Chin Wook

    2009-10-01

    Real time two-dimensional spatial distribution measurement method of electron temperature and plasma density was developed. It is based on a floating probe method [1] because the floating probe has high time resolution. Two-dimensional array of sensors on a 300 mm diameter wafer-shaped printed circuit board (PCB) and a high speed multiplexer circuit were used for real time distribution measurement. The method was tested at various powers and pressures, spatial distributions of the electron temperature and the plasma density could be obtained. And in the measurement results, asymmetric plasma density distributions caused by pumping port effect could be observed. This method can measure spatial distribution of plasma parameters on the wafer in real time without plasma perturbation, therefore it will be expected to improve the uniformity of processing plasmas such as etching and deposition. [4pt] [1] M. H. Lee, S. H. Jang, C. W. Chung, J. Appl. Phys. 101, 033305 (2007).

  3. [Comparison of direct immune-fluorescent assay and real-time quantitative PCR in detecting the Hantavirus].

    PubMed

    Yu, Peng-bo; Li, Shen; Wei, Jing; Ma, Chang-an; Lu, Xiao-ling; DU, Shui-quan; Guan, Lu-yuan; Zheng, Yuan; Dong, Jian-hua; Ma, Chao-feng; Wang, Jing-jun

    2013-04-01

    To compare the differences between the direct immuno-fluorescent assay (DFA) and real-time quantitative PCR in detecting the Hantavirus (HV) in rat lungs. From April to October in 2012, a total of 479 rats were caught by mouse-trap in residential or wild areas in Huxian, Jingyang, and Meixian of Shaanxi province, where haemorrhagic fever with renal syndrome (HFRS) was highly prevalent. The rats were dissected to take the two lungs, one was frozen and applied immuno-fluorescent assay to detect HV antigen while the other one was extracted its RNA and detected HV nucleic acid by real-time quantitative PCR. Then we compared the positive rate of the two methods. Out of the 479 rats, 105 were caught from residential areas and the other 374 were caught from wild areas. Among the 105 rats caught from residential areas, no HV were detected out neither by DFA nor by real-time quantitative PCR. Among the 374 wild rats, 13.1% (49/374) were detected HV positive by DFA and 14.7% (55/374) were detected HV positive by real-time quantitative PCR. The difference showed no statistical significance (χ(2) = 0.402, P = 0.526). When detecting each lung sample, the HV positive rate was 10.2% (49/479) under the detection by DFA while the HV positive rate was 11.5% (55/479) under the detection by real-time quantitative PCR. The difference had no statistical significance (χ(2) = 1.286, P = 0.257) and the consistency coefficient was 68.2% under the paired chi-square test analysis, which showed high consistency (u = 11.759, P < 0.05). The sensitivity of real-time quantitative PCR to detect HV was 77.6% (38/49) comparing with DFA as standard, and the specificity was 96.1% (413/430). Out of the 9 suspected HV positive sample detected by DFA, 6 were confirmed positive by real-time quantitative PCR and 3 were denied. Compared with the DFA, real-time quantitative PCR could also be used to detect the infection of HV in rats, and the result might be more stable.

  4. Alterations of lymph flow after lymphadenectomy in rats revealed by real time fluorescence imaging system.

    PubMed

    Takeno, Y; Fujimoto, E

    2013-03-01

    Secondary lymphedema is one of the sequella of cancer treatment that in inadequately understood. The purpose of the present study is to investigate lymphedema formation and to explore the escape routes for excess interstitial fluid using lymphadenectomy in a rat model. In twelve Wistar rats, lymph nodes in the right inguinal and popliteal fossas were completely removed and lymph vessels carefully ligated. After operation, treated hind limbs were evaluated by indocyanine green lymphography and circumferential measurement. Both evaluations were performed from day 3 to ten weeks. Approximately 2 to 3 weeks after operation, a network-like pattern of the fluorescent signal appeared around the surgical site which then transitioned into a linear pattern in the lower abdomen. Videorecordings identified fluorescent flow moving from the lower abdomen to the ipsilateral axillary lymph node and in some rats, the network-like pattern was also observed to pass transversely over the suprapubic region to the contralateral inguinal lymph nodes. The network-like pattern on the lower abdomen and the linear pattern to the axillary fossa were seen continuously to the end of observation. Circumferential measurements of the treated hind limbs increased initially and then declined over time. This imaging system may be useful to detect early changes in lymphatic flow before swelling occurs and further study is needed.

  5. Real-time intermembrane force measurements and imaging of lipid domain morphology during hemifusion

    PubMed Central

    Lee, Dong Woog; Kristiansen, Kai; Donaldson, Jr., Stephen H.; Cadirov, Nicholas; Banquy, Xavier; Israelachvili, Jacob N.

    2015-01-01

    Membrane fusion is the core process in membrane trafficking and is essential for cellular transport of proteins and other biomacromolecules. During protein-mediated membrane fusion, membrane proteins are often excluded from the membrane–membrane contact, indicating that local structural transformations in lipid domains play a major role. However, the rearrangements of lipid domains during fusion have not been thoroughly examined. Here using a newly developed Fluorescence Surface Forces Apparatus (FL-SFA), migration of liquid-disordered clusters and depletion of liquid-ordered domains at the membrane–membrane contact are imaged in real time during hemifusion of model lipid membranes, together with simultaneous force–distance and lipid membrane thickness measurements. The load and contact time-dependent hemifusion results show that the domain rearrangements decrease the energy barrier to fusion, illustrating the significance of dynamic domain transformations in membrane fusion processes. Importantly, the FL-SFA can unambiguously correlate interaction forces and in situ imaging in many dynamic interfacial systems. PMID:26006266

  6. Real-time long term measurement using integrated framework for ubiquitous smart monitoring

    NASA Astrophysics Data System (ADS)

    Heo, Gwanghee; Lee, Giu; Lee, Woosang; Jeon, Joonryong; Kim, Pil-Joong

    2007-04-01

    Ubiquitous monitoring combining internet technologies and wireless communication is one of the most promising technologies of infrastructure health monitoring against the natural of man-made hazards. In this paper, an integrated framework of the ubiquitous monitoring is developed for real-time long term measurement in internet environment. This framework develops a wireless sensor system based on Bluetooth technology and sends measured acceleration data to the host computer through TCP/IP protocol. And it is also designed to respond to the request of web user on real time basis. In order to verify this system, real time monitoring tests are carried out on a prototype self-anchored suspension bridge. Also, wireless measurement system is analyzed to estimate its sensing capacity and evaluate its performance for monitoring purpose. Based on the evaluation, this paper proposes the effective strategies for integrated framework in order to detect structural deficiencies and to design an early warning system.

  7. Real-time measurement of small molecules directly in awake, ambulatory animals

    PubMed Central

    Somerson, Jacob; Vieira, Philip A.; Ploense, Kyle L.; Kippin, Tod E.; Plaxco, Kevin W.

    2017-01-01

    The development of a technology capable of tracking the levels of drugs, metabolites, and biomarkers in the body continuously and in real time would advance our understanding of health and our ability to detect and treat disease. It would, for example, enable therapies guided by high-resolution, patient-specific pharmacokinetics (including feedback-controlled drug delivery), opening new dimensions in personalized medicine. In response, we demonstrate here the ability of electrochemical aptamer-based (E-AB) sensors to support continuous, real-time, multihour measurements when emplaced directly in the circulatory systems of living animals. Specifically, we have used E-AB sensors to perform the multihour, real-time measurement of four drugs in the bloodstream of even awake, ambulatory rats, achieving precise molecular measurements at clinically relevant detection limits and high (3 s) temporal resolution, attributes suggesting that the approach could provide an important window into the study of physiology and pharmacokinetics. PMID:28069939

  8. Fluorescence-based enhanced reality (FLER) for real-time estimation of bowel perfusion in minimally invasive surgery

    NASA Astrophysics Data System (ADS)

    Diana, Michele

    2016-03-01

    Pre-anastomotic bowel perfusion is a key factor for a successful healing process. Clinical judgment has limited accuracy to evaluate intestinal microperfusion. Fluorescence videography is a promising tool for image-guided intraoperative assessment of the bowel perfusion at the future anastomotic site in the setting of minimally invasive procedures. The standard configuration for fluorescence videography includes a Near-Infrared endoscope able to detect the signal emitted by a fluorescent dye, more frequently Indocyanine Green (ICG), which is administered by intravenous injection. Fluorescence intensity is proportional to the amount of fluorescent dye diffusing in the tissue and consequently is a surrogate marker of tissue perfusion. However, fluorescence intensity alone remains a subjective approach and an integrated computer-based analysis of the over-time evolution of the fluorescence signal is required to obtain quantitative data. We have developed a solution integrating computer-based analysis for intra-operative evaluation of the optimal resection site, based on the bowel perfusion as determined by the dynamic fluorescence intensity. The software can generate a "virtual perfusion cartography", based on the "fluorescence time-to-peak". The virtual perfusion cartography can be overlapped onto real-time laparoscopic images to obtain the Enhanced Reality effect. We have defined this approach FLuorescence-based Enhanced Reality (FLER). This manuscript describes the stepwise development of the FLER concept.

  9. Real-time fluorescence target/background (T/B) ratio calculation in multimodal endoscopy for detecting GI tract cancer

    NASA Astrophysics Data System (ADS)

    Jiang, Yang; Gong, Yuanzheng; Wang, Thomas D.; Seibel, Eric J.

    2017-02-01

    Multimodal endoscopy, with fluorescence-labeled probes binding to overexpressed molecular targets, is a promising technology to visualize early-stage cancer. T/B ratio is the quantitative analysis used to correlate fluorescence regions to cancer. Currently, T/B ratio calculation is post-processing and does not provide real-time feedback to the endoscopist. To achieve real-time computer assisted diagnosis (CAD), we establish image processing protocols for calculating T/B ratio and locating high-risk fluorescence regions for guiding biopsy and therapy in Barrett's esophagus (BE) patients. Methods: Chan-Vese algorithm, an active contour model, is used to segment high-risk regions in fluorescence videos. A semi-implicit gradient descent method was applied to minimize the energy function of this algorithm and evolve the segmentation. The surrounding background was then identified using morphology operation. The average T/B ratio was computed and regions of interest were highlighted based on user-selected thresholding. Evaluation was conducted on 50 fluorescence videos acquired from clinical video recordings using a custom multimodal endoscope. Results: With a processing speed of 2 fps on a laptop computer, we obtained accurate segmentation of high-risk regions examined by experts. For each case, the clinical user could optimize target boundary by changing the penalty on area inside the contour. Conclusion: Automatic and real-time procedure of calculating T/B ratio and identifying high-risk regions of early esophageal cancer was developed. Future work will increase processing speed to <5 fps, refine the clinical interface, and apply to additional GI cancers and fluorescence peptides.

  10. Real-time autocorrelator for fluorescence correlation spectroscopy based on graphical-processor-unit architecture: method, implementation, and comparative studies

    NASA Astrophysics Data System (ADS)

    Laracuente, Nicholas; Grossman, Carl

    2013-03-01

    We developed an algorithm and software to calculate autocorrelation functions from real-time photon-counting data using the fast, parallel capabilities of graphical processor units (GPUs). Recent developments in hardware and software have allowed for general purpose computing with inexpensive GPU hardware. These devices are more suited for emulating hardware autocorrelators than traditional CPU-based software applications by emphasizing parallel throughput over sequential speed. Incoming data are binned in a standard multi-tau scheme with configurable points-per-bin size and are mapped into a GPU memory pattern to reduce time-expensive memory access. Applications include dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS) experiments. We ran the software on a 64-core graphics pci card in a 3.2 GHz Intel i5 CPU based computer running Linux. FCS measurements were made on Alexa-546 and Texas Red dyes in a standard buffer (PBS). Software correlations were compared to hardware correlator measurements on the same signals. Supported by HHMI and Swarthmore College

  11. An optical real-time 3D measurement for analysis of facial shape and movement

    NASA Astrophysics Data System (ADS)

    Zhang, Qican; Su, Xianyu; Chen, Wenjing; Cao, Yiping; Xiang, Liqun

    2003-12-01

    Optical non-contact 3-D shape measurement provides a novel and useful tool for analysis of facial shape and movement in presurgical and postsurgical regular check. In this article we present a system, which allows a precise 3-D visualization of the patient's facial before and after craniofacial surgery. We discussed, in this paper, the real time 3-D image capture, processing and the 3-D phase unwrapping method to recover complex shape deformation when the movement of the mouth. The result of real-time measurement for facial shape and movement will be helpful for the more ideal effect in plastic surgery.

  12. Real-time phase measurement of optical vortices based on pixelated micropolarizer array.

    PubMed

    Zhang, Zhigang; Dong, Fengliang; Qian, Kemao; Zhang, Qingchuan; Chu, Weiguo; Zhang, Yuntian; Ma, Xuan; Wu, Xiaoping

    2015-08-10

    The special spiral phase structure of an optical vortex leads to an intriguing study in modern singular optics. This paper proposes a real-time phase measurement method of vortex beam based on pixelated micropolarizer array (PMA). Four phase-shifting fringe images can be obtained from a single interference image, thus the vortex beam phase can be obtained in real-time. The proposed method can achieve full-field phase measurement of the vortex beam with the advantages of lower computation and vibration resistance. In the experiments, the typical phases of vortex with different topological charges are loaded on a spatial light modulator (SLM) to generate diffraction vortex beam, and the phase distribution of vortex beam is obtained in real-time, which confirm the robustness of this method. This method is of great significance in promoting the study of optical vortices.

  13. Use of endogenous NADH fluorescence for real-time in situ visualization of epicardial radiofrequency ablation lesions and gaps

    PubMed Central

    Mercader, Marco; Swift, Luther; Sood, Sumit; Asfour, Huda; Kay, Matthew

    2012-01-01

    Radiofrequency ablation (RFA) aims to produce lesions that interrupt reentrant circuits or block the spread of electrical activation from sites of abnormal activity. Today, there are limited means for real-time visualization of cardiac muscle tissue injury during RFA procedures. We hypothesized that the fluorescence of endogenous NADH could be used as a marker of cardiac muscle injury during epicardial RFA procedures. Studies were conducted in blood-free and blood-perfused hearts from healthy adult Sprague-Dawley rats and New Zealand rabbits. Radiofrequency was applied to the epicardial surface of the heart using a 4-mm standard blazer ablation catheter. A dual camera optical mapping system was used to monitor NADH fluorescence upon ultraviolet illumination of the epicardial surface and to record optical action potentials using the voltage-sensitive probe RH237. Epicardial lesions were seen as areas of low NADH fluorescence. The lesions appeared immediately after ablation and remained stable for several hours. Real-time monitoring of NADH fluorescence allowed visualization of viable tissue between the RFA lesions. Dual recordings of NADH and epicardial electrical activity linked the gaps between lesions to postablation reentries. We found that the fluorescence of endogenous NADH aids the visualization of injured epicardial tissue caused by RFA. This was true for both blood-free and blood-perfused preparations. Gaps between NADH-negative regions revealed unablated tissue, which may promote postablation reentry or provide pathways for the conduction of abnormal electrical activity. PMID:22408016

  14. Real-time Fluorescence Polarization Microscopy of the Moving Boundary in Cross-Gradient SDS-PAGE

    NASA Astrophysics Data System (ADS)

    Hwang, Jeeseong; Giulian, Gary

    2003-03-01

    Real-time Fluorescence Polarization Microscopy of the Moving Boundary in Cross-Gradient SDS-PAGE Jeeseong Hwang, Jeffrey R. Krogmeier, Angela M. Bardo, Scott N. Goldie, Lori S. Goldner; Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 Gary G. Giulian, Carl R. Merril; National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892 Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) is a popular method to separate proteins by their apparent molecular weight. However, it is a limited technique due, in part, to its low spatial resolution. In order to improve the resolution and to enhance the detection sensitivity of proteins separated by SDS-PAGE we are studying the detergent properties at the moving boundary of precast Tris-Tricine-Acetate cross-gradient gels using fluorescent cationic and pH indicating dyes. We have developed real-time full-field fluorescence polarization microscopy to monitor the dynamic fluorescence anisotropy from the cationic tetramethylindocarbocyanine dyes localized in the "extended stack", a concentrated detergent zone. We will present quantitative results of the fluorescence anisotropy. Our system is capable of analyzing local structures of the detergent molecules in the moving boundary of SDS-PAGE and the microenvironment(s) near the boundary. We will discuss the significance of these results and their potential role in enhanced protein separation.

  15. Laser-induced fluorescence method of molecular iodine detection in the atmosphere in real time using copper-vapor laser at the wavelength of 510.6 nm

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2017-06-01

    The method of simultaneously detecting 127I2 and 127I129I in the atmospheric air is proposed. The method is based on exciting fluorescence of the molecules in question by copper-vapor laser radiation at the wavelength of 510.6 nm and registering intensities of their individual fluorescence spectral lines. The values of minimal real-time measured relative concentrations of 127I129I being mixed with 127I2 are approximately 10-6. This method can be used for the ecological monitoring of iodine-129 in the atmosphere.

  16. In vitro Real-time Measurement of the Intra-bacterial Redox Potential

    PubMed Central

    van der Heijden, Joris; Finlay, B. Brett

    2016-01-01

    All bacteria that live in oxygenated environments have to deal with oxidative stress caused by some form of exogenous or endogenous reactive oxygen species (ROS) (Imlay, 2013). Large quantities of ROS damage DNA, lipids and proteins which can eventually lead to bacterial cell death (Imlay, 2013). In contrast, smaller quantities of ROS can play more sophisticated roles in cellular signalling pathways affecting almost every process in the bacterial cell e.g. metabolism, stress responses, transcription, protein synthesis, etc. Previously, inadequate analytical methods prevented appropriate analysis of the intra-bacterial redox potential. Herein, we describe a method for the measurement of real-time changes to the intra-bacterial redox potential using redox-sensitive GFP (roGFP2) (van der Heijden et al., 2015). The roGFP2 protein is engineered to contain specific cysteine residues that form an internal disulfide bridge upon oxidation which results in a slight shift in protein conformation (Hanson et al., 2004). This shift results in two distinct protein isoforms with different fluorescence excitation spectra after excitation at 405 nm and 480 nm respectively. Consequently, the corresponding 405/480 nm ratio can be used as a measure for the intra-bacterial redox potential. The ratio-metric analysis excludes variations due to differences in roGFP2 concentrations and since the conformational shift is reversible the system allows for measurement of oxidizing as well as reducing conditions. In this protocol we describe the system by measuring the intra-bacterial redox potential inside Salmonella typhimurium (S. typhimurium) however this system can be adjusted for use in other Gram-negative bacteria. PMID:27617271

  17. An Instrument for Real-Time Measurement of Solid Rocket Motor Insulation Erosion

    NASA Technical Reports Server (NTRS)

    McWhorter, B. B.

    1999-01-01

    An instrument (eroding potentionmeter) has been designed to measure real-time case wall and inhibitor insulation char depth within a rocket motor during firing. Thus measurement can be close to the real-time recession of the insulation surface. The eroding potentionmeter consists of two small (3 mils 9in diameter) twisted resistive wires that are polyimide insulated. The wire pair form an electrical circuit and will recede with the erosion of the rocket motor internal insulation. A constant current applied along the wires will detect the resistance change via a voltage drop across the wires as the wire pair recedes with the decomposition fo the insulation. The eroding potentionmeter, as presently designed, can be an effective tool for real time measurement of internal insulation recession of a solid rocket motor. This tool will provide a way to accurately measure inhibitor performance or to measure flight effects of insulation erosion on a flight test. The eroding potentiometer has been verified on a plasma torch test and two static tests of a small solid rocket motor. There are some irregularities in the measured date, but the data remains useful in determining the real-time performance of internal insulation during a motor firing.

  18. Observation of development of breast cancer cell lines in real time by fluorescence microscopy under simulated microgravity

    NASA Astrophysics Data System (ADS)

    Lavan, David; Valdivia-Silva, Julio E.; Sanabria, Gabriela; Orihuela, Diego; Suarez, Juan; Quispe, Marco; Chuchon, Mariano; Martin, David; Maroto, Marcos; Egea, Javier

    2016-07-01

    This project consist in the implementation of a fluorescence microscope for the in real time monitoring of biological labeled samples by several fluorophores in microgravity conditions keeping the temperature, humidity, and (CO)2 controlled by an electronic platform. The system (fluorescence microscope and incubator) is integrated to a microgravity simulator machine which was presented on the "30th Annual American Society for Gravitation and Space Research Meeting" October 2014 in Pasadena, CA, USA. Currently, we have the microgravity machine biologically validated by genetic expression studies in pupal stage of Drosophila melanogaster. The fluorescence microscope has a platform designed to hold a culture flask, and a fluorescence camera (Leica DFC3000 G) connected to an optical system (Fluorescence Light source Leica EL6000, optic fiber, fiber adapter, and fluorescence filter) in order to take images in real time. The mechanical system of the fluorescence microsc ope is designed to allow the displacement of the fluorescence camera through a parallel plane to the culture flask's plane and also the movement of the platform through a perpendicular axis to the culture flask in order to focus the samples to the optical system. The mechanical system is propelled by four DC moto-reductors with encoder (A-max 26 Maxon motor, GP 32S screw and MR encoder) that generate displacements in the order of micrometers. The angular position control of the DC motoreductor's shaft of all the DC moto-reductors is done by PWM signals based on the interpretation of the signals provided by the encoders during the movement. The system is remotely operated by a graphic interface installed on a personal computer or any mobile device (smartphone, laptop or tablet) by using the internet. Acknowledgments: Grant of INNOVATE PERU (Formerly FINCYT)

  19. [Detection of hematopoietic chimera by real-time fluorescent quantitative PCR with erythrocyte Kidd blood group gene].

    PubMed

    Chen, Shu; Xu, Xian-Guo; Liu, Ying; Hong, Xiao-Zhen; Zhu, Fa-Ming; Lü, Hang-Jun; Yan, Li-Xing

    2012-06-01

    This study was aimed to establish the real-time fluorescent quantitative PCR (RT-qPCR) with erythrocyte Kidd blood group gene for detecting the hematopoietic chimera and to investigate the feasibility of this method. The TaqMan MGB probes and special primers were designed on basis of difference of erythrocyte Kidd blood group alleles, the hematopoietic chimerism was detected by RT-qPCR, the DNA chimerism was simulated by means of dilution of multiple proportions, and the sensitivity analysis was performed. The results showed that the RT-qPCR with erythrocyte Kidd blood group gene could effectively distinguish JK*A and JK*B alleles. There was no significant difference between the theoretic value and the practical measured value by this method (P > 0.05). As 156 donor's cells could be discriminated from 10(4) chimeric cells, this method may effectively detect donor's cells with correlation coefficient 0.998. It is concluded that the established RT-qPCR with erythrocyte Kidd blood group gene shows the feasibility for quantitative detection of hematopoietic chimera, and may be used to quantitatively detect chimera in a certain range.

  20. Real-time monitoring of NKCC2 endocytosis by total internal reflection fluorescence (TIRF) microscopy.

    PubMed

    Jaykumar, Ankita Bachhawat; Caceres, Paulo S; Sablaban, Ibrahim; Tannous, Bakhos A; Ortiz, Pablo A

    2016-01-15

    The apical Na-K-2Cl cotransporter (NKCC2) mediates NaCl reabsorption by the thick ascending limb (TAL). The amount of NKCC2 at the apical membrane of TAL cells is determined by exocytic delivery, recycling, and endocytosis. Surface biotinylation allows measurement of NKCC2 endocytosis, but it has low time resolution and does not allow imaging of the dynamic process of endocytosis. We hypothesized that total internal reflection fluorescence (TIRF) microscopy imaging of labeled NKCC2 would allow monitoring of NKCC2 endocytosis in polarized Madin-Darby canine kidney (MDCK) and TAL cells. Thus we generated a NKCC2 construct containing a biotin acceptor domain (BAD) sequence between the transmembrane domains 5 and 6. Once expressed in polarized MDCK or TAL cells, surface NKCC2 was specifically biotinylated by exogenous biotin ligase (BirA). We also demonstrate that expression of a secretory form of BirA in TAL cells induces metabolic biotinylation of NKCC2. Labeling biotinylated surface NKCC2 with fluorescent streptavidin showed that most apical NKCC2 was located within small discrete domains or clusters referred to as "puncta" on the TIRF field. NKCC2 puncta were observed to disappear from the TIRF field, indicating an endocytic event which led to a decrease in the number of surface puncta at a rate of 1.18 ± 0.16%/min in MDCK cells, and a rate 1.09 ± 0.08%/min in TAL cells (n = 5). Treating cells with a cholesterol-chelating agent (methyl-β-cyclodextrin) completely blocked NKCC2 endocytosis. We conclude that TIRF microscopy of labeled NKCC2 allows the dynamic imaging of individual endocytic events at the apical membrane of TAL cells.

  1. Noninvasive real-time fluorescence imaging of the lymphatic uptake of BSA-IRDye 680 conjugate administered subcutaneously in mice.

    PubMed

    Wu, Fang; Bhansali, Suraj G; Tamhane, Mitalee; Kumar, Rajiv; Vathy, Lisa A; Ding, Hong; Yong, Ken-Tye; Bergey, Earl J; Prasad, Paras N; Morris, Marilyn E

    2012-05-01

    The goal of our studies was to determine lymphatic uptake of bovine serum albumin (BSA) using real-time noninvasive fluorescence imaging. BSA labeled with near-infrared dye (IRDye) 680 was used as a model protein-dye conjugate. The conjugation of BSA with IRDye 680 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Size-exclusion high-performance liquid chromatography and SDS-PAGE demonstrated that the IRDye 680-labeled BSA conjugate in the lymph node (LN) homogenate samples was stable at physiological temperature (37°C) for at least 5 days. Whole-body noninvasive optical imaging of hairless SKH-1 mice was performed after subcutaneous (s.c.) injection (dose = 0.1 mg/kg) into the front footpad. Noninvasive fluorescence imaging demonstrated that BSA-IRDye 680 conjugates were dynamically taken up by the lymphatic system, accumulated in the axillary LNs and then cleared, indicating that lymphatic transport plays a role in the absorption of BSA. Ex vivo tissue imaging of LN homogenates provided confirmatory data with respect to the uptake of fluorescent-labeled BSA determined by in vivo imaging. Noninvasive real-time imaging of LNs provides a novel tool for evaluating uptake and accumulation of fluorescent-labeled proteins by the lymphatic system after s.c. injection in a mouse model. Copyright © 2012 Wiley Periodicals, Inc.

  2. Using Biometric Measurement in Real-Time as a Sympathetic System in Computer Games

    ERIC Educational Resources Information Center

    Charij, Stephanie; Oikonomou, Andreas

    2013-01-01

    With the increasing potential for gaming hardware and peripherals to support biometrics, their application within the games industry for software and design should be considered. This paper assesses the ability to use a form of biometric measurement, heart rate, in real-time to improve the challenge and enjoyment of a game by catering it to…

  3. Depressed mood in individuals with schizophrenia: a comparison of retrospective and real-time measures

    PubMed Central

    Blum, Lisa H.; Vakhrusheva, Julia; Saperstein, Alice; Khan, Samira; Chang, Rachel W.; Hansen, Marie C.; Zemon, Vance; Kimhy, David

    2015-01-01

    Depressed mood is prevalent among individuals with schizophrenia, leading to difficulties in functioning. Typically, depressed mood is evaluated using retrospective assessments during which individuals are asked to recall their mood during the past week or month. However, as individuals with schizophrenia may display memory difficulties, the results of such assessments may be biased, potentially leading to inaccurate clinical characterizations and/or suboptimal treatment. Our aim was to assess the potential impact of long-term memory on depressed mood in individuals with schizophrenia. Employing an Experience Sampling Method (ESM) approach, 51 individuals with schizophrenia and 22 healthy controls rated their momentary emotions up to 10 times/day over a two-day period, along with retrospective measures of depressed mood, long-term memory, quality of life, social functioning, and symptoms. ESM assessment of real-time depressed mood demonstrated discriminant and convergent validity. Among the schizophrenia group, there was a significant correlation between the real-time and retrospective measures of depressed mood. However, once variance due to long-term memory was controlled, the relationship between the real-time and retrospective measure was no longer significant. The findings suggest that a real-time measure of depressed mood may allow overcoming some of the limitations associated with long-term memory difficulties common among individuals with schizophrenia. PMID:25895490

  4. Using Biometric Measurement in Real-Time as a Sympathetic System in Computer Games

    ERIC Educational Resources Information Center

    Charij, Stephanie; Oikonomou, Andreas

    2013-01-01

    With the increasing potential for gaming hardware and peripherals to support biometrics, their application within the games industry for software and design should be considered. This paper assesses the ability to use a form of biometric measurement, heart rate, in real-time to improve the challenge and enjoyment of a game by catering it to…

  5. Flavin Mononucleotide-Based Fluorescent Reporter Proteins Outperform Green Fluorescent Protein-Like Proteins as Quantitative In Vivo Real-Time Reporters▿

    PubMed Central

    Drepper, Thomas; Huber, Robert; Heck, Achim; Circolone, Franco; Hillmer, Anne-Kathrin; Büchs, Jochen; Jaeger, Karl-Erich

    2010-01-01

    Fluorescent proteins of the green fluorescent protein (GFP) family are commonly used as reporter proteins for quantitative analysis of complex biological processes in living microorganisms. Here we demonstrate that the fluorescence signal intensity of GFP-like proteins is affected under oxygen limitation and therefore does not reflect the amount of reporter protein in Escherichia coli batch cultures. Instead, flavin mononucleotide (FMN)-binding fluorescent proteins (FbFPs) are suitable for quantitative real-time in vivo assays under these conditions. PMID:20601504

  6. Chemical luminescence measurement of singlet oxygen generated by photodynamic therapy in solutions in real time

    NASA Astrophysics Data System (ADS)

    Luo, Shiming; Xing, Da; Zhou, Jing; Qin, Yanfang; Chen, Qun

    2005-04-01

    Photodynamic therapy (PDT) is a cancer therapy that utilizes optical energy to activate a photosensitizer drug in a target tissue. Reactive oxygen species (ROS), such as 1O2 and superoxide, are believed to be the major cytotoxic agents involved in PDT. Although current PDT dosimetry mostly involves measurements of light and photosensitizer doses delivered to a patient, the quantification of ROS production during a treatment would be the ultimate dosimetry of PDT. Technically, it is very difficult and expensive to directly measure the fluorescence from 1O2, due to its extreme short lifetime and weak signal strength. In this paper, Photofrin(R) and 635nm laser were used to generate 1O2 and superoxide in a PDT in solution. Compound 3,7- dihydro-6-{4-[2-(N"-(5-fluoresceinyl) thioureido) ethoxy] phenyl}-2- methylimidazo{1,2-a} pyrazin-3-one sodium salt,an Cyp- ridina luciferin analog commonly referred as FCLA, was used as a chemical reporter of ROS. The 532nm chemiluminescence (CL) from the reaction of the FCLA and ROS was detected with a photon multiplier tube (PMT) system operating at single photon counting mode. With the setup, we have made detections of ROS generated by PDT in real time. By varying the amount of conventional PDT dosage (photosensitizer concentration, light irradiation fluence and its delivery rate) and the amount of FCLA, the intensity of CL and its consumption rate were investigated. The results show that the intensity and temporal profile of CL are highly related to the PDT treatment parameters. This suggests that FCLA CL may provide a highly potential alternative for ROS detection during PDT.

  7. Real-time 3D measurement based on structured light illumination considering camera lens distortion

    NASA Astrophysics Data System (ADS)

    Feng, Shijie; Chen, Qian; Zuo, Chao; Sun, Jiasong; Yu, ShiLing

    2014-12-01

    Optical three-dimensional (3-D) profilometry is gaining increasing attention for its simplicity, flexibility, high accuracy, and non-contact nature. Recent advances in imaging sensors and digital projection technology further its progress in high-speed, real-time applications, enabling 3-D shapes reconstruction of moving objects and dynamic scenes. In traditional 3-D measurement system where the processing time is not a key factor, camera lens distortion correction is performed directly. However, for the time-critical high-speed applications, the time-consuming correction algorithm is inappropriate to be performed directly during the real-time process. To cope with this issue, here we present a novel high-speed real-time 3-D coordinates measuring technique based on fringe projection with the consideration of the camera lens distortion. A pixel mapping relation between a distorted image and a corrected one is pre-determined and stored in computer memory for real-time fringe correction. And a method of lookup table (LUT) is introduced as well for fast data processing. Our experimental results reveal that the measurement error of the in-plane coordinates has been reduced by one order of magnitude and the accuracy of the out-plane coordinate been tripled after the distortions being eliminated. Moreover, owing to the merit of the LUT, the 3-D reconstruction can be achieved at 92.34 frames per second.

  8. DNA detection of Clostridium difficile infection based on real-time resistance measurement.

    PubMed

    Liu, C; Jiang, D N; Xiang, G M; Luo, F K; Liu, L L; Yu, J C; Pu, X Y

    2013-09-03

    We used a newly developed electrochemical method, real-time resistance measurement, based on loop-mediated isothermal amplification (LAMP), with real-time resistance monitoring and derivative analysis. DNA extracted from specimens was amplified through LAMP reaction. The 2 products of LAMP, DNA and pyrophosphate, both are negative ions; they combine with positive dye (crystal violet) and positive ions (Mg(2+)), which leads to an increase in the resistivity of the reaction liquid. The changes of resistivity were measured in real-time with a specially designed resistance electrode, to detect Clostridium difficile DNA. We found that electrochemical detection of C. difficile could be completed in 0.5-1 h, with a detection limit of 10(2) CFU/mL, with high accuracy (95.0%), sensitivity (91.1%), and specificity (97.3%) compared to PCR methods. C. difficile is commonly associated with antibiotic-induced diarrhea. Due to the difficulty in performing anaerobic culture and cytotoxicity neutralization assays, a simple, rapid, sensitive, and accurate method is preferred. We conclude that real-time resistance measurement is a rapid, sensitive, and stable method for the diagnosis of C. difficile infection that could be applied to gene chips and pocket instruments.

  9. Real-time remote detection and measurement for airborne imaging spectroscopy: a case study with methane

    NASA Astrophysics Data System (ADS)

    Thompson, D. R.; Leifer, I.; Bovensmann, H.; Eastwood, M.; Fladeland, M.; Frankenberg, C.; Gerilowski, K.; Green, R. O.; Kratwurst, S.; Krings, T.; Luna, B.; Thorpe, A. K.

    2015-10-01

    Localized anthropogenic sources of atmospheric CH4 are highly uncertain and temporally variable. Airborne remote measurement is an effective method to detect and quantify these emissions. In a campaign context, the science yield can be dramatically increased by real-time retrievals that allow operators to coordinate multiple measurements of the most active areas. This can improve science outcomes for both single- and multiple-platform missions. We describe a case study of the NASA/ESA CO2 and MEthane eXperiment (COMEX) campaign in California during June and August/September 2014. COMEX was a multi-platform campaign to measure CH4 plumes released from anthropogenic sources including oil and gas infrastructure. We discuss principles for real-time spectral signature detection and measurement, and report performance on the NASA Next Generation Airborne Visible Infrared Spectrometer (AVIRIS-NG). AVIRIS-NG successfully detected CH4 plumes in real-time at Gb s-1 data rates, characterizing fugitive releases in concert with other in situ and remote instruments. The teams used these real-time CH4 detections to coordinate measurements across multiple platforms, including airborne in situ, airborne non-imaging remote sensing, and ground-based in situ instruments. To our knowledge this is the first reported use of real-time trace-gas signature detection in an airborne science campaign, and presages many future applications. Post-analysis demonstrates matched filter methods providing noise-equivalent (1σ) detection sensitivity for 1.0 % CH4 column enhancements equal to 141 ppm m.

  10. A non-invasive fluorescence-based oxygen sensor and platform for studying cell responses to metabolic agents in real-time

    NASA Astrophysics Data System (ADS)

    Buchapudi, Koutilya Reddy

    A fluorescence-based sensor in a transverse flow/stop measurement platform has been developed to determine real-time changes in oxygen consumption rates for cell metabolic studies. The oxygen sensitive fluorophore platinum octaethylporphyrin was embedded in a cellulose acetate matrix and affixed to a fiber optic bundle, which provided for transmission of the excitation and emission wavelengths of the film. The fiber optic bundle was sealed in a sensor head that can be used in standard 24-well plates common to research labs. The utility of the sensor and sensing platform were determined by measuring the changes in oxygen consumption rates of Candida albicans during 90/30 s flow/stop cycles. Exposure of these cells to metabolic antagonists and an enhancer showed the expected decrease and increase in oxygen consumption rates in real time. The applicability of the platform to biological studies is illustrated by determination of synergistic activities between antifungal drugs and fluoride exposure in Candida albicans. The robustness of the fluorophore film is demonstrated by perfusion with different media and analyte conditions in the absence of cells. For stop cycle time intervals less than 1 minute the sensor exhibited a rapid and fairly linear change in fluorescence intensity to changing oxygen concentrations in the measurement chamber. Flow cycle fluorescence intensities were used as a baseline correction for treating the stop cycle fluorescence peaks.

  11. Advanced fluorescence microscopy methods for the real-time study of transcription and chromatin dynamics

    PubMed Central

    Annibale, Paolo; Gratton, Enrico

    2014-01-01

    In this contribution we provide an overview of the recent advances allowed by the use of fluorescence microscopy methods in the study of transcriptional processes and their interplay with the chromatin architecture in living cells. Although the use of fluorophores to label nucleic acids dates back at least to about half a century ago,1 two recent breakthroughs have effectively opened the way to use fluorescence routinely for specific and quantitative probing of chromatin organization and transcriptional activity in living cells: namely, the possibility of labeling first the chromatin loci and then the mRNA synthesized from a gene using fluorescent proteins. In this contribution we focus on methods that can probe rapid dynamic processes by analyzing fast fluorescence fluctuations. PMID:25764219

  12. Real-time emission factor measurements of isocyanic acid from light duty gasoline vehicles

    NASA Astrophysics Data System (ADS)

    Brady, J.; Crisp, T. A.; Collier, S.; Kuwayama, T.; Zhang, Q.; Kleeman, M.; Bertram, T. H.

    2013-12-01

    Recent work has demonstrated the potential for vehicle based anthropogenic sources of the carcinogen isocyanic acid (HNCO) in urban environments. Although emission factors for HNCO have recently been measured for light duty diesel vehicles, light duty gasoline vehicles are not well characterized. Here we will present real-time emission factor measurements of HNCO for light duty gasoline vehicles measured at the California Air Resource Board's Haagen-Smit Laboratory in September of 2011 driven on a chassis dynamometer using the California Unified Driving Cycle. Emission factors for HNCO were determined for eight light duty gasoline vehicles utilizing a fast response chemical ionization time-of-flight mass spectrometer and simultaneous real-time measurements of CO, CO2, and NOx. We will discuss the potential production mechanism for HNCO by light duty gasoline vehicles as well as the potential drive cycle dependency of HNCO production.

  13. Study on a real-time visual measuring and tracking system for industry robot welding

    NASA Astrophysics Data System (ADS)

    Liu, Chang-jie; Zhu, Ji-gui; Li, Yan-bin; Ye, Sheng-hua

    2006-06-01

    The industry welding robot can't real-time adjust its movement path according to the change in the position of the workpiece in a welding procedure, which affects the quality of welding a lot. The Real-time Visual Measuring and Tracking system acquires the three coordinates of the workpiece by visual measurement method, and navigates the robot to the correct position, consequently the welding quality improves. The system mainly includes micro structured-light visual sensors, a high-speed data processing unit, a display and setting unit, and protection equipments. From the experiment, it's shown that the system can measure the workpiece six times per second, and the precision of the measurement is better than 0.3mm. In a word, the system can effectively improve the robot welding quality.

  14. An orange fluorescent protein tagging system for real-time pollen tracking

    PubMed Central

    2013-01-01

    Background Monitoring gene flow could be important for future transgenic crops, such as those producing plant-made-pharmaceuticals (PMPs) in open field production. A Nicotiana hybrid (Nicotiana. tabacum × Nicotiana glauca) shows limited male fertility and could be used as a bioconfined PMP platform. Effective assessment of gene flow from these plants is augmented with methods that utilize fluorescent proteins for transgenic pollen identification. Results We report the generation of a pollen tagging system utilizing an orange fluorescent protein to monitor pollen flow and as a visual assessment of transgene zygosity of the parent plant. This system was created to generate a tagged Nicotiana hybrid that could be used for the incidence of gene flow. Nicotiana tabacum ‘TN 90’ and Nicotiana glauca were successfully transformed via Agrobacterium tumefaciens to express the orange fluorescent protein gene, tdTomato-ER, in pollen and a green fluorescent protein gene, mgfp5-er, was expressed in vegetative structures of the plant. Hybrids were created that utilized the fluorescent proteins as a research tool for monitoring pollen movement and gene flow. Manual greenhouse crosses were used to assess hybrid sexual compatibility with N. tabacum, resulting in seed formation from hybrid pollination in 2% of crosses, which yielded non-viable seed. Pollen transfer to the hybrid formed seed in 19% of crosses and 10 out of 12 viable progeny showed GFP expression. Conclusion The orange fluorescent protein is visible when expressed in the pollen of N. glauca, N. tabacum, and the Nicotiana hybrid, although hybrid pollen did not appear as bright as the parent lines. The hybrid plants, which show limited ability to outcross, could provide bioconfinement with the benefit of detectable pollen using this system. Fluorescent protein-tagging could be a valuable tool for breeding and in vivo ecological monitoring. PMID:24070251

  15. Quantitation of Viral DNA by Real-Time PCR Applying Duplex Amplification, Internal Standardization, and Two-Color Fluorescence Detection

    PubMed Central

    Gruber, Franz; Falkner, Falko G.; Dorner, Friedrich; Hämmerle, Thomas

    2001-01-01

    A real-time PCR method was developed to quantitate viral DNA that includes duplex amplification, internal standardization, and two-color fluorescence detection without the need to generate an external standardization curve. Applied to human parvovirus B19 DNA, the linear range was from 102 to at least 5 × 106 copies per ml of sample. The coefficient of variation was 0.29 using a run control of 2,876 copies per ml. The method reduces the risk of false-negative results, yields high precision, and is applicable for other DNA targets. PMID:11375203

  16. Digital Holography for in Situ Real-Time Measurement of Plasma-Facing-Component Erosion

    SciTech Connect

    ThomasJr., C. E.; Granstedt, E. M.; Biewer, Theodore M; Baylor, Larry R; Combs, Stephen Kirk; Meitner, Steven J; Hillis, Donald Lee; Majeski, R.; Kaita, R.

    2014-01-01

    In situ, real time measurement of net plasma-facing-component (PFC) erosion/deposition in a real plasma device is challenging due to the need for good spatial and temporal resolution, sufficient sensitivity, and immunity to fringe-jump errors. Design of a high-sensitivity, potentially high-speed, dual-wavelength CO2 laser digital holography system (nominally immune to fringe jumps) for PFC erosion measurement is discussed.

  17. Digital holography for in situ real-time measurement of plasma-facing-component erosion.

    PubMed

    Thomas, C E Tommy; Granstedt, E M; Biewer, T M; Baylor, L R; Combs, S K; Meitner, S J; Hillis, D L; Majeski, R; Kaita, R

    2014-11-01

    In situ, real time measurement of net plasma-facing-component (PFC) erosion/deposition in a real plasma device is challenging due to the need for good spatial and temporal resolution, sufficient sensitivity, and immunity to fringe-jump errors. Design of a high-sensitivity, potentially high-speed, dual-wavelength CO2 laser digital holography system (nominally immune to fringe jumps) for PFC erosion measurement is discussed.

  18. Augmented microscopy: real-time overlay of bright-field and near-infrared fluorescence images.

    PubMed

    Watson, Jeffrey R; Gainer, Christian F; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G Michael; Anton, Rein; Romanowski, Marek

    2015-10-01

    Intraoperative applications of near-infrared (NIR) fluorescent contrast agents can be aided by instrumentation capable of merging the view of surgical field with that of NIR fluorescence. We demonstrate augmented microscopy, an intraoperative imaging technique in which bright-field (real) and electronically processed NIR fluorescence (synthetic) images are merged within the optical path of a stereomicroscope. Under luminance of 100,000 lx, representing typical illumination of the surgical field, the augmented microscope detects 189 nM concentration of indocyanine green and produces a composite of the real and synthetic images within the eyepiece of the microscope at 20 fps. Augmentation described here can be implemented as an add-on module to visualize NIR contrast agents, laser beams, or various types of electronic data within the surgical microscopes commonly used in neurosurgical, cerebrovascular, otolaryngological, and ophthalmic procedures.

  19. Augmented microscopy: real-time overlay of bright-field and near-infrared fluorescence images

    PubMed Central

    Watson, Jeffrey R.; Gainer, Christian F.; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G. Michael; Anton, Rein; Romanowski, Marek

    2015-01-01

    Abstract. Intraoperative applications of near-infrared (NIR) fluorescent contrast agents can be aided by instrumentation capable of merging the view of surgical field with that of NIR fluorescence. We demonstrate augmented microscopy, an intraoperative imaging technique in which bright-field (real) and electronically processed NIR fluorescence (synthetic) images are merged within the optical path of a stereomicroscope. Under luminance of 100,000 lx, representing typical illumination of the surgical field, the augmented microscope detects 189 nM concentration of indocyanine green and produces a composite of the real and synthetic images within the eyepiece of the microscope at 20 fps. Augmentation described here can be implemented as an add-on module to visualize NIR contrast agents, laser beams, or various types of electronic data within the surgical microscopes commonly used in neurosurgical, cerebrovascular, otolaryngological, and ophthalmic procedures. PMID:26440760

  20. Augmented microscopy: real-time overlay of bright-field and near-infrared fluorescence images

    NASA Astrophysics Data System (ADS)

    Watson, Jeffrey R.; Gainer, Christian F.; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G. Michael, Jr.; Anton, Rein; Romanowski, Marek

    2015-10-01

    Intraoperative applications of near-infrared (NIR) fluorescent contrast agents can be aided by instrumentation capable of merging the view of surgical field with that of NIR fluorescence. We demonstrate augmented microscopy, an intraoperative imaging technique in which bright-field (real) and electronically processed NIR fluorescence (synthetic) images are merged within the optical path of a stereomicroscope. Under luminance of 100,000 lx, representing typical illumination of the surgical field, the augmented microscope detects 189 nM concentration of indocyanine green and produces a composite of the real and synthetic images within the eyepiece of the microscope at 20 fps. Augmentation described here can be implemented as an add-on module to visualize NIR contrast agents, laser beams, or various types of electronic data within the surgical microscopes commonly used in neurosurgical, cerebrovascular, otolaryngological, and ophthalmic procedures.

  1. An inductive sensor for real-time measurement of plantar normal and shear forces distribution.

    PubMed

    Du, Li; Zhu, Xiaoliang; Zhe, Jiang

    2015-05-01

    The objective of this paper is to demonstrate a multiplexed inductive force sensor for simultaneously measuring normal force and shear forces on a foot. The sensor measures the normal force and shear forces by monitoring the inductance changes of three planar sensing coils. Resonance frequency division multiplexing was applied to signals from the multiple sensing coils, making it feasible to simultaneously measure the three forces (normal force, shear forces in x- and y-axis) on a foot using only one set of measurement electronics with high sensitivity and resolution. The testing results of the prototype sensor have shown that the sensor is capable of measuring normal force ranging from 0 to 800 N and shear forces ranging from 0 to 130 N in real time. With its high resolution, high sensitivity, and the capability of monitoring forces at different positions of a foot simultaneously, this sensor can be potentially used for real-time measurement of plantar normal force and shear forces distribution on diabetes patient's foot. Real-time monitoring of the normal force and shear forces on diabetes patient's foot can provide useful information for physicians and diabetes patients to take actions in preventing foot ulceration.

  2. Development of real-time photoelectric measurement on geometric size of objects

    NASA Astrophysics Data System (ADS)

    Yuan, Guangming; Li, Tianze

    2009-05-01

    The characteristic and work principium of Charge Coupled Devices (CCD) is expatiated. Based on CCD measuring technology, a geometric objects photoelectric comprehensive measuring system is described in the paper, which is applied to measure the thickness of quartz tube wall non-contacted automatically with a line CCD device. The system is composed of a semiconductor laser source, a main fine mechanic system and controller, a real-time controlling system with SCM and data processing system by PC. The optics system, CCD hardware circuit and SCM control system are mainly discussed in this system. The system work process: optics, machine, electron and computer are organically combined, the line CCD in this instrument can measure the distance between two laser beams which are reflected from the outside and inside surfaces of quartz tube wall. Comparisons between the system and traditional measurement instrument are provided with: high measurement precision and efficiency; celerity and real time. In addition, applications of the system are viewed in the geometric objects foot-line real-time detection of the tube wall thickness and plank thickness, and medicine and liquor manufacturing, and the system error is analyzed.

  3. Real-time measurements of corticosteroids in conscious animals using an antibody-based electrode.

    PubMed

    Cook, C J

    1997-05-01

    An electrochemical immunosensor for real-time determination of corticosteroids, a group of steroidal hormones, is reported. The sensor measures competitive binding of endogenous corticosteroid and a corticosteroid-peroxidase conjugate with antibodies, immobilized on a platinum electrode, by monitoring of peroxidase activity. The electrode is encased within a dialysate membrane, which separates the electrode environment from the sampled fluid, allowing corticosteroid to equilibrate across the membrane. This permits measurements to be made in vivo. The small size of the probe (350 microns D) allows implantation into tissue or circulatory systems. The electrode was viable for 200 to 400 sequential measurements and at least 48 h in vivo. Detection sensitivity is 0.2 to 0.6 microgram/100 ml of cortisol or corticosterone. The results suggest the possibility of monitoring hormones in real-time within the blood or organ systems of conscious animals.

  4. Real-time measurement of electron beam weld penetration in uranium by acoustic emission monitoring

    SciTech Connect

    Whittaker, J.W.; Murphy, J.L.

    1991-07-01

    High quality electron beam (EB) welds are required in uranium test articles. Acoustic emission (AE) techniques are under development with the goal of measuring weld penetration in real-time. One technique, based on Average Signal Level (ASL) measurement was used to record weld AE signatures. Characteristic AE signatures were recorded for bead-on-plate (BOP) and butt joint (BJ) welds made under varied welding conditions. AE waveforms were sampled to determine what microscopic AE behavior led to the observed macroscopic signature features. Deformation twinning and weld expulsion are two of the main sources of emission. AE behavior was correlated with weld penetration as measured by standard metallographic techniques. The ASL value was found to increase approximately linearly with weld penetration in BJ welds. These results form the basis for a real-time monitoring technique for weld penetration. 5 refs.

  5. LANL's near-real-time measurement control bolt-on to LANMAS

    SciTech Connect

    Hicks, Ruel D; Boyle, Caroline M

    2010-01-01

    Los Alamos National Laboratory (LANL) has created a near-real-time Measurement Control Program (MCP) that integrates with Local Area Network Material Accounting System (LANMAS). The program was designed to take the place of an aging accounting system at LANL which incorporated the measurement control. LANL's Material Control and Accountability (MC&A) group developed many bolt-on features to enhance LANMAS called LAM CAS (Los Alamos Material Control and Accounting System), one of those bolt-on enhancements was to develop the MCP to replace the previous version. MCP was developed with the multiple end-user groups in mind by creating a near-real-time system that was user friendly, provided access controls, and account status of the measurement control systems.

  6. Real-time locating and speed measurement of fibre fuse using optical frequency-domain reflectometry

    PubMed Central

    Jiang, Shoulin; Ma, Lin; Fan, Xinyu; Wang, Bin; He, Zuyuan

    2016-01-01

    We propose and experimentally demonstrate real-time locating and speed measurement of fibre fuse by analysing the Doppler shift of reflected light using optical frequency-domain reflectometry (OFDR). Our method can detect the start of a fibre fuse within 200 ms which is equivalent to a propagation distance of about 10 cm in standard single-mode fibre. We successfully measured instantaneous speed of propagating fibre fuses and observed their subtle fluctuation owing to the laser power instability. The resolution achieved for speed measurement in our demonstration is 1 × 10−3 m/s. We studied the fibre fuse propagation speed dependence on the launched power in different fibres. Our method is promising for both real time fibre fuse monitoring and future studies on its propagation and termination. PMID:27146550

  7. The detection of T-Nos, a genetic element present in GMOs, by cross-priming isothermal amplification with real-time fluorescence.

    PubMed

    Zhang, Fang; Wang, Liu; Fan, Kai; Wu, Jian; Ying, Yibin

    2014-05-01

    An isothermal cross-priming amplification (CPA) assay for Agrobacterium tumefaciens nopaline synthase terminator (T-Nos) was established and investigated in this work. A set of six specific primers, recognizing eight distinct regions on the T-Nos sequence, was designed. The CPA assay was performed at a constant temperature, 63 °C, and detected by real-time fluorescence. The results indicated that real-time fluorescent CPA had high specificity, and the limit of detection was 1.06 × 10(3) copies of rice genomic DNA, which could be detected in 40 min. Comparison of real-time fluorescent CPA and conventional polymerase chain reaction (PCR) was also performed. Results revealed that real-time fluorescent CPA had a comparable sensitivity to conventional real-time PCR and had taken a shorter time. In addition, different contents of genetically modified (GM)-contaminated rice seed powder samples were detected for practical application. The result showed real-time fluorescent CPA could detect 0.5 % GM-contaminated samples at least, and the whole reaction could be finished in 35 min. Real-time fluorescent CPA is sensitive enough to monitor labeling systems and provides an attractive method for the detection of GMO.

  8. Real-Time Inhibitor Recession Measurements in the Space Shuttle Reusable Solid Rocket Motors

    NASA Technical Reports Server (NTRS)

    McWhorter, Bruce B.; Ewing, Mark E.; McCool, Alex (Technical Monitor)

    2001-01-01

    Real-time char line recession measurements were made on propellant inhibitors of the Space Shuttle Reusable Solid Rocket Motor (RSRM). The RSRM FSM-8 static test motor propellant inhibitors (composed of a rubber insulation material) were successfully instrumented with eroding potentiometers and thermocouples. The data was used to establish inhibitor recession versus time relationships. Normally, pre-fire and post-fire insulation thickness measurements establish the thermal performance of an ablating insulation material. However, post-fire inhibitor decomposition and recession measurements are complicated by the fact that most of the inhibitor is back during motor operation. It is therefore a difficult task to evaluate the thermal protection offered by the inhibitor material. Real-time measurements would help this task. The instrumentation program for this static test motor marks the first time that real-time inhibitors. This report presents that data for the center and aft field joint forward facing inhibitors. The data was primarily used to measure char line recession of the forward face of the inhibitors which provides inhibitor thickness reduction versus time data. The data was also used to estimate the inhibitor height versus time relationship during motor operation.

  9. Real-time electron density measurements from Cotton-Mouton effect in JET machine

    SciTech Connect

    Brombin, M.; Boboc, A.; Zabeo, L.

    2008-10-15

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  10. Real-time electron density measurements from Cotton-Mouton effect in JET machine.

    PubMed

    Brombin, M; Boboc, A; Zabeo, L; Murari, A

    2008-10-01

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  11. Length-dependent flagellar growth of Vibrio alginolyticus revealed by real time fluorescent imaging

    PubMed Central

    Chen, Meiting; Zhao, Ziyi; Yang, Jin; Peng, Kai; Baker, Matthew AB; Bai, Fan; Lo, Chien-Jung

    2017-01-01

    Bacterial flagella are extracellular filaments that drive swimming in bacteria. During motor assembly, flagellins are transported unfolded through the central channel in the flagellum to the growing tip. Here, we applied in vivo fluorescent imaging to monitor in real time the Vibrio alginolyticus polar flagella growth. The flagellar growth rate is found to be highly length-dependent. Initially, the flagellum grows at a constant rate (50 nm/min) when shorter than 1500 nm. The growth rate decays sharply when the flagellum grows longer, which decreases to ~9 nm/min at 7500 nm. We modeled flagellin transport inside the channel as a one-dimensional diffusive process with an injection force at its base. When the flagellum is short, its growth rate is determined by the loading speed at the base. Only when the flagellum grows longer does diffusion of flagellin become the rate-limiting step, dramatically reducing the growth rate. Our results shed new light on the dynamic building process of this complex extracellular structure. DOI: http://dx.doi.org/10.7554/eLife.22140.001 PMID:28098557

  12. 3D real-time measurement system of seam with laser

    NASA Astrophysics Data System (ADS)

    Huang, Min-shuang; Huang, Jun-fen

    2014-02-01

    3-D Real-time Measurement System of seam outline based on Moiré Projection is proposed and designed. The system is composed of LD, grating, CCD, video A/D, FPGA, DSP and an output interface. The principle and hardware makeup of high-speed and real-time image processing circuit based on a Digital Signal Processor (DSP) and a Field Programmable Gate Array (FPGA) are introduced. Noise generation mechanism in poor welding field conditions is analyzed when Moiré stripes are projected on a welding workpiece surface. Median filter is adopted to smooth the acquired original laser image of seam, and then measurement results of a 3-D outline image of weld groove are provided.

  13. Using fluorescence lymphangiography to define the ileocolic mesentery: proof of concept for the watershed area using real-time imaging.

    PubMed

    Keller, D S; Joshi, H M; Rodriguez-Justo, M; Walsh, D; Coffey, J C; Chand, M

    2017-08-29

    Recent advances in mesenteric science have demonstrated that the mesentery is a continuous structure with a 'watershed' area at the mesenteric apex between the right colon and terminal ileum, where lymphatic flow can proceed either proximally or distally. With this new understanding of the anatomy, functional features are emerging, which can have an impact on surgical management. Fluorescence lymphangiography or lymphoscintigraphy with indocyanine green allows real-time visualization of lymphatic channels, which highlights sentinel lymph nodes and may facilitate identification of the ideal margins for mesenteric lymphadenectomy during bowel resection for colon cancer. By using this novel technology, it is possible to demonstrate a watershed area in the ileocolic region and may facilitate more precise mesenteric dissection. In the present study, we provide proof of concept for the ileocolic watershed area using fluorescence lymphangiography.

  14. Real-time analysis and selection of methylated DNA by fluorescence-activated single molecule sorting in a nanofluidic channel.

    PubMed

    Cipriany, Benjamin R; Murphy, Patrick J; Hagarman, James A; Cerf, Aline; Latulippe, David; Levy, Stephen L; Benítez, Jaime J; Tan, Christine P; Topolancik, Juraj; Soloway, Paul D; Craighead, Harold G

    2012-05-29

    Epigenetic modifications, such as DNA and histone methylation, are responsible for regulatory pathways that affect disease. Current epigenetic analyses use bisulfite conversion to identify DNA methylation and chromatin immunoprecipitation to collect molecules bearing a specific histone modification. In this work, we present a proof-of-principle demonstration for a new method using a nanofluidic device that combines real-time detection and automated sorting of individual molecules based on their epigenetic state. This device evaluates the fluorescence from labeled epigenetic modifications to actuate sorting. This technology has demonstrated up to 98% accuracy in molecule sorting and has achieved postsorting sample recovery on femtogram quantities of genetic material. We have applied it to sort methylated DNA molecules using simultaneous, multicolor fluorescence to identify methyl binding domain protein-1 (MBD1) bound to full-duplex DNA. The functionality enabled by this nanofluidic platform now provides a workflow for color-multiplexed detection, sorting, and recovery of single molecules toward subsequent DNA sequencing.

  15. Real-time thermal imaging of microwave accelerated metal-enhanced fluorescence (MAMEF) based assays on sapphire plates.

    PubMed

    Previte, Michael J R; Zhang, Yongxia; Aslan, Kadir; Geddes, Chris D

    2007-11-01

    In this paper, we describe an optical geometry that facilitates our further characterization of the temperature changes above silver island films (SiFs) on sapphire plates, when exposed to microwave radiation. Since sapphire transmits IR, we designed an optical scheme to capture real-time temperature images of a thin water film on sapphire plates with and without SiFs during the application of a short microwave pulse. Using this optical scheme, we can accurately determine the temperature profile of solvents in proximity to metal structures when exposed to microwave irradiation. We believe that this optical scheme will provide us with a basis for further studies in designing metal structures to further improve plasmonic-fluorescence clinical sensing applications, such as those used in microwave accelerated metal-enhanced fluorescence (MAMEF).

  16. Analytical real-time measurement of a three-dimensional weld pool surface

    NASA Astrophysics Data System (ADS)

    Zhang, WeiJie; Wang, XueWu; Zhang, YuMing

    2013-11-01

    The ability to observe and measure weld pool surfaces in real-time is the core of the foundation for next generation intelligent welding that can partially imitate skilled welders who observe the weld pool to acquire information on the welding process. This study aims at the real-time measurement of the specular three-dimensional (3D) weld pool surface under a strong arc in gas tungsten arc welding (GTAW). An innovative vision system is utilized in this study to project a dot-matrix laser pattern on the specular weld pool surface. Its reflection from the surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser dots illuminate this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern (e.g. the dot matrix) is used to derive the 3D shape of the reflection surface, i.e., the weld pool surface. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution is proposed to solve this formulated problem resulting in the weld pool surface being reconstructed on average in 3.04 ms during welding experiments. A vision-based monitoring system is thus established to measure the weld pool surface in GTAW in real-time. In order to verify the effectiveness of the proposed reconstruction algorithm, first numerical simulation is conducted. The proposed algorithm is then tested on a spherical convex mirror with a priori knowledge of its geometry. The detailed analysis of the measurement error validates the accuracy of the proposed algorithm. Results from the real-time experiments verify the robustness of the proposed reconstruction algorithm.

  17. Real time measurement of epilayer strain using a simplified wafer curvature technique

    SciTech Connect

    Floro, J.A.; Chason, E.; Lee, S.R.

    1995-12-31

    We describe a technique for measuring thin film stress using wafer curvature that is robust, compact, easy to setup, and sufficiently sensitive to serve as a routine diagnostic of semiconductor epilayer strain in real time during MBE or CVD growth. We demonstrate, using growth of SiGe alloys on Si, that the critical thickness for misfit dislocation can clearly be resolved, and that the subsequent strain relaxation kinetics during growth or post-growth annealing are readily obtained.

  18. Real-time three-dimensional counting and shape measurement of RBCs using digital holographic cytometry

    NASA Astrophysics Data System (ADS)

    Funamizu, Hideki; Sonoda, Kotaro; Goto, Ryoji; Aizu, Yoshihisa

    2017-04-01

    Digital holography is a useful technique for recording and reconstruction of the complex amplitude of an optical field. In this technique, an interference pattern of two waves is detected by an image sensor, and digital holograms are acquired in computer. The wavefront is reconstructed by a numerical calculation. In this study, we present the real-time threedimensional counting and shape measurement of RBCs using flow cytometry with digital holographic microscopy.

  19. Simultaneous fitting of real-time PCR data with efficiency of amplification modeled as Gaussian function of target fluorescence

    PubMed Central

    Batsch, Anke; Noetel, Andrea; Fork, Christian; Urban, Anita; Lazic, Daliborka; Lucas, Tina; Pietsch, Julia; Lazar, Andreas; Schömig, Edgar; Gründemann, Dirk

    2008-01-01

    Background In real-time PCR, it is necessary to consider the efficiency of amplification (EA) of amplicons in order to determine initial target levels properly. EAs can be deduced from standard curves, but these involve extra effort and cost and may yield invalid EAs. Alternatively, EA can be extracted from individual fluorescence curves. Unfortunately, this is not reliable enough. Results Here we introduce simultaneous non-linear fitting to determine – without standard curves – an optimal common EA for all samples of a group. In order to adjust EA as a function of target fluorescence, and still to describe fluorescence as a function of cycle number, we use an iterative algorithm that increases fluorescence cycle by cycle and thus simulates the PCR process. A Gauss peak function is used to model the decrease of EA with increasing amplicon accumulation. Our approach was validated experimentally with hydrolysis probe or SYBR green detection with dilution series of 5 different targets. It performed distinctly better in terms of accuracy than standard curve, DART-PCR, and LinRegPCR approaches. Based on reliable EAs, it was possible to detect that for some amplicons, extraordinary fluorescence (EA > 2.00) was generated with locked nucleic acid hydrolysis probes, but not with SYBR green. Conclusion In comparison to previously reported approaches that are based on the separate analysis of each curve and on modelling EA as a function of cycle number, our approach yields more accurate and precise estimates of relative initial target levels. PMID:18267040

  20. Real-Time Characterization of Virulence Factor Expression in Yersinia pestis Using a Green Fluorescent Protein Reporter System

    SciTech Connect

    Forde, C; Rocco, J; Fitch, J P; McCutchen-Maloney, S

    2004-06-09

    A real-time reporter system was developed to monitor the thermal induction of virulence factors in Yersinia pestis. The reporter system consists of a plasmid in Y. pestis in which the expression of green fluorescent protein (GFP) is under the control of the promoters for six virulence factors, yopE, sycE, yopK, yopT, yscN, and lcrE/yopN, which are all components of the Type III secretion virulence mechanism of Y. pestis. Induction of the expression of these genes in vivo was determined by the increase in fluorescence intensity of GFP in real time. Basal expression levels observed for the Y. pestis promoters, expressed as percentages of the positive control with GFP under the control of the lac promoter, were: yopE (15%), sycE (15%), yopK (13%), yopT (4%), lcrE (3.3%) and yscN (0.8%). The yopE reporter showed the strongest gene induction following temperature transition from 26 C to 37 C. The induction levels of the other virulence factors, expressed as percentages of yopE induction, were: yopK (57%), sycE (9%), yscN (3%), lcrE (3%), and yopT (2%). The thermal induction of each of these promoter fusions was repressed by calcium, and the ratios of the initial rates of thermal induction without calcium supplementation compared to the rate with calcium supplementation were: yopE (11 fold), yscN (7 fold), yopK (6 fold), lcrE (3 fold), yopT (2 fold), and sycE (2 fold). This work demonstrates a novel approach to quantify gene induction and provides a method to rapidly determine the effects of external stimuli on expression of Y. pestis virulence factors in real time, in living cells.

  1. Estimation of Candida albicans ABC Transporter Behavior in Real-Time via Fluorescence.

    PubMed

    Szczepaniak, Joanna; Łukaszewicz, Marcin; Krasowska, Anna

    2015-01-01

    We present a fluorometric method for determining ABC transporter activity in the pathogenic fungus C. albicans during different growth phases and in response to glucose. The carbocyanine dye diS-C3(3) was previously used to monitor plasma membrane potentials and test the influence of surface-active compounds in membrane polarization. We used diS-C3(3) to show changes in fluorescence kinetics that reflect changes in the activity of ABC transporters in C. albicans growth. Cdr1-GFP fluorescence, revealed that Cdr1p relocates to the inside of the cell after the early-log growth phase. Addition of glucose to the cell suspension resulted in Cdr1p transporter expression in the CDR2-knockout strain. We confirmed the diS-C3(3) results by standard RT-PCR and Western blotting.

  2. Real-time visualization of caspase-3 activation by fluorescence resonance energy transfer (FRET).

    PubMed

    Alasia, Silvia; Cocito, Carolina; Merighi, Adalberto; Lossi, Laura

    2015-01-01

    As apoptosis occurs via a complex signaling cascade that is tightly regulated at multiple cell points, different methods exist to evaluate the activity of the proteins involved in the intracellular apoptotic pathways and the phenotype of apoptotic neurons. Detention of the activity of the enzyme caspase-3, the key executioner caspase in programmed cell death, by laser scanning confocal fluorescence microscopy and the fluorescence resonance energy transfer technology is an alternative approach to classical standard techniques, such as Western blotting, activity assays, or histological techniques, and allows working with both fixed and living cells. This technique combined with the organotypic culture approach ex vivo represents a valid tool for the study of the mechanisms of neuronal survival /death and neuroprotection.

  3. Fluorescent Microscope System to Monitor Real-Time Interactions between Focused Ultrasound, Echogenic Drug Delivery Vehicles, and Live Cell Membranes

    PubMed Central

    Ibsen, Stuart; Benchimol, Michael; Esener, Sadik

    2012-01-01

    Rapid development in the field of ultrasound triggered drug delivery has made it essential to study the real-time interaction between the membranes of live cells and the membranes of echogenic delivery vehicles under exposure to focused ultrasound. The objective of this work was to design an analysis system that combined fluorescent imagining, high speed videography, and definable pulse sequences of focused ultrasound to allow for real time observations of both cell and vehicle membranes. Documenting the behavior of the membranes themselves has not previously been possible due to limitations with existing optical systems used to understand the basic physics of microbubble/ultrasound interaction and the basic interaction between microbubbles and cells. The performance of this new system to monitor membrane behavior was demonstrated by documenting the modes of vehicle fragmentation at different ultrasound intensity levels. At 1.5 MPa the membranes were shown to completely fragment while at intensities below 1 MPa there is a popping and slow unfolding. The interaction between these vehicles and cell membranes was also documented by the removal of fluorescent particles from the surfaces of live cells out to 20 μm from the microbubble location. The fluid flow created by microstreaming around ensonated microbubbles was documented at video recording speeds from 60 to 18,000 frames per second. This information about membrane behavior allows the chemical and physical properties of the drug delivery vehicle to be designed along with the ultrasound pulse sequence to cause the most efficient drug delivery. PMID:22749476

  4. Infection of zebrafish embryos with live fluorescent Streptococcus pneumoniae as a real-time pneumococcal meningitis model.

    PubMed

    Jim, Kin Ki; Engelen-Lee, JooYeon; van der Sar, Astrid M; Bitter, Wilbert; Brouwer, Matthijs C; van der Ende, Arie; Veening, Jan-Willem; van de Beek, Diederik; Vandenbroucke-Grauls, Christina M J E

    2016-08-19

    Streptococcus pneumoniae is one of the most important causes of bacterial meningitis, an infection where unfavourable outcome is driven by bacterial and host-derived toxins. In this study, we developed and characterized a pneumococcal meningitis model in zebrafish embryos that allows for real-time investigation of early host-microbe interaction. Zebrafish embryos were infected in the caudal vein or hindbrain ventricle with green fluorescent wild-type S. pneumoniae D39 or a pneumolysin-deficient mutant. The kdrl:mCherry transgenic zebrafish line was used to visualize the blood vessels, whereas phagocytic cells were visualized by staining with far red anti-L-plastin or in mpx:GFP/mpeg1:mCherry zebrafish, that have green fluorescent neutrophils and red fluorescent macrophages. Imaging was performed by fluorescence confocal and time-lapse microscopy. After infection by caudal vein, we saw focal clogging of the pneumococci in the blood vessels and migration of bacteria through the blood-brain barrier into the subarachnoid space and brain tissue. Infection with pneumolysin-deficient S. pneumoniae in the hindbrain ventricle showed attenuated growth and migration through the brain as compared to the wild-type strain. Time-lapse and confocal imaging revealed that the initial innate immune response to S. pneumoniae in the subarachnoid space mainly consisted of neutrophils and that pneumolysin-mediated cytolytic activity caused a marked reduction of phagocytes. This new meningitis model permits detailed analysis and visualization of host-microbe interaction in pneumococcal meningitis in real time and is a very promising tool to further our insights in the pathogenesis of pneumococcal meningitis.

  5. Real-time full bandwidth measurement of spectral noise in supercontinuum generation

    PubMed Central

    Wetzel, B.; Stefani, A.; Larger, L.; Lacourt, P. A.; Merolla, J. M.; Sylvestre, T.; Kudlinski, A.; Mussot, A.; Genty, G.; Dias, F.; Dudley, J. M.

    2012-01-01

    The ability to measure real-time fluctuations of ultrashort pulses propagating in optical fiber has provided significant insights into fundamental dynamical effects such as modulation instability and the formation of frequency-shifting rogue wave solitons. We report here a detailed study of real-time fluctuations across the full bandwidth of a fiber supercontinuum which directly reveals the significant variation in measured noise statistics across the spectrum, and which allows us to study correlations between widely separated spectral components. For two different propagation distances corresponding to the onset phase of spectral broadening and the fully-developed supercontinuum, we measure real time noise across the supercontinuum bandwidth, and we quantify the supercontinuum noise using statistical higher-order moments and a frequency-dependent intensity correlation map. We identify correlated spectral regions within the supercontinuum associated with simultaneous sideband generation, as well as signatures of pump depletion and soliton-like pump dynamics. Experimental results are in excellent agreement with simulations. PMID:23193436

  6. Real-time measurement of dust in the workplace using video exposure monitoring: Farming to pharmaceuticals

    NASA Astrophysics Data System (ADS)

    Walsh, P. T.; Forth, A. R.; Clark, R. D. R.; Dowker, K. P.; Thorpe, A.

    2009-02-01

    Real-time, photometric, portable dust monitors have been employed for video exposure monitoring (VEM) to measure and highlight dust levels generated by work activities, illustrate dust control techniques, and demonstrate good practice. Two workplaces, presenting different challenges for measurement, were used to illustrate the capabilities of VEM: (a) poultry farming activities and (b) powder transfer operations in a pharmaceutical company. For the poultry farm work, the real-time monitors were calibrated with respect to the respirable and inhalable dust concentrations using cyclone and IOM reference samplers respectively. Different rankings of exposure for typical activities were found on the small farm studied here compared to previous exposure measurements at larger poultry farms: these were mainly attributed to the different scales of operation. Large variations in the ratios of respirable, inhalable and real-time monitor TWA concentrations of poultry farm dust for various activities were found. This has implications for the calibration of light-scattering dust monitors with respect to inhalable dust concentration. In the pharmaceutical application, the effectiveness of a curtain barrier for dust control when dispensing powder in a downflow booth was rapidly demonstrated.

  7. The Potential Applications of Real-Time Monitoring of Water Quality in a Large Shallow Lake (Lake Taihu, China) Using a Chromophoric Dissolved Organic Matter Fluorescence Sensor

    PubMed Central

    Niu, Cheng; Zhang, Yunlin; Zhou, Yongqiang; Shi, Kun; Liu, Xiaohan; Qin, Boqiang

    2014-01-01

    This study presents results from field surveys performed over various seasons in a large, eutrophic, shallow lake (Lake Taihu, China) using an in situ chromophoric dissolved organic matter (CDOM) fluorescence sensor as a surrogate for other water quality parameters. These measurements identified highly significant empirical relationships between CDOM concentration measured using the in situ fluorescence sensor and CDOM absorption, fluorescence, dissolved organic carbon (DOC), chemical oxygen demand (COD) and total phosphorus (TP) concentrations. CDOM concentration expressed in quinine sulfate equivalent units, was highly correlated with the CDOM absorption coefficient (r2 = 0.80, p < 0.001), fluorescence intensities (Ex./Em. 370/460 nm) (r2 = 0.91, p < 0.001), the fluorescence index (r2 = 0.88, p < 0.001) and the humification index (r2 = 0.78, p < 0.001), suggesting that CDOM concentration measured using the in situ fluorescence sensor could act as a substitute for the CDOM absorption coefficient and fluorescence measured in the laboratory. Similarly, CDOM concentration was highly correlated with DOC concentration (r2 = 0.68, p < 0.001), indicating that in situ CDOM fluorescence sensor measurements could be a proxy for DOC concentration. In addition, significant positive correlations were found between laboratory CDOM absorption coefficients and COD (r2 = 0.83, p < 0.001), TP (r2 = 0.82, p < 0.001) concentrations, suggesting a potential further application for the real-time monitoring of water quality using an in situ CDOM fluorescence sensor. PMID:24984060

  8. Real-Time Aerodynamic Parameter Estimation without Air Flow Angle Measurements

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2010-01-01

    A technique for estimating aerodynamic parameters in real time from flight data without air flow angle measurements is described and demonstrated. The method is applied to simulated F-16 data, and to flight data from a subscale jet transport aircraft. Modeling results obtained with the new approach using flight data without air flow angle measurements were compared to modeling results computed conventionally using flight data that included air flow angle measurements. Comparisons demonstrated that the new technique can provide accurate aerodynamic modeling results without air flow angle measurements, which are often difficult and expensive to obtain. Implications for efficient flight testing and flight safety are discussed.

  9. Real-Time Stability Margin Measurements for X-38 Robustness Analysis

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Stachowiak, Susan J.

    2005-01-01

    A method has been developed for real-time stability margin measurement calculations. The method relies on a tailored-forced excitation targeted to a specific frequency range. Computation of the frequency response is matched to the specific frequencies contained in the excitation. A recursive Fourier transformation is used to make the method compatible with real-time calculation. The method was incorporated into the X-38 nonlinear simulation and applied to an X-38 robustness test. X-38 stability margins were calculated for different variations in aerodynamic and mass properties over the vehicle flight trajectory. The new method showed results comparable to more traditional stability analysis techniques, and at the same time, this new method provided coverage that is more complete and increased efficiency.

  10. Fully integrated whole blood testing by real-time absorption measurement on a centrifugal platform.

    PubMed

    Steigert, J; Grumann, M; Brenner, T; Riegger, L; Harter, J; Zengerle, R; Ducrée, J

    2006-08-01

    We present a novel microfluidic concept to enable a fast colorimetric alcohol assay from a single droplet of whole blood. The reduced turn-around time of 150 seconds is, on the one hand, achieved by a full process integration including metering, mixing with reagents, and sedimentation of cellular constituents. On the other hand, our novel total internal reflection (TIR) scheme allows to monitor the increase of the absorbance values in real-time. Thus, the saturation values can be predicted accurately based on an extrapolation of real-time measurements acquired during a 100 second initial period of rotation. Additionally, we present a metering structure to define nanolitre sample volumes at a coefficient of variation (CV) below 5%.

  11. Real-time data acquisition and control system for the measurement of motor and neural data

    PubMed Central

    Bryant, Christopher L.; Gandhi, Neeraj J.

    2013-01-01

    This paper outlines a powerful, yet flexible real-time data acquisition and control system for use in the triggering and measurement of both analog and digital events. Built using the LabVIEW development architecture (version 7.1) and freely available, this system provides precisely timed auditory and visual stimuli to a subject while recording analog data and timestamps of neural activity retrieved from a window discriminator. The system utilizes the most recent real-time (RT) technology in order to provide not only a guaranteed data acquisition rate of 1 kHz, but a much more difficult to achieve guaranteed system response time of 1 ms. The system interface is windows-based and easy to use, providing a host of configurable options for end-user customization. PMID:15698659

  12. Dynamical theory of spin noise and relaxation: Prospects for real-time NMR measurements.

    PubMed

    Field, Timothy R

    2014-11-01

    Recent developments in theoretical aspects of spin noise and relaxation and their interrelationship reveal a modified spin density, distinct from the density matrix, as the necessary object to describe fluctuations in spin systems. These fluctuations are to be viewed as an intrinsic quantum mechanical property of such systems immersed in random magnetic environments and are observed as "spin noise" in the absence of any radio frequency excitation. With the prospect of ultrafast digitization, the role of spin noise in real-time parameter extraction for (NMR) spin systems, and the advantage over standard techniques, is of essential importance, especially for systems containing a small number of spins. In this article we outline prospects for harnessing the recent dynamical theory in terms of spin-noise measurement, with attention to real-time properties.

  13. Development of a capacitive ice sensor to measure ice growth in real time.

    PubMed

    Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

    2015-03-19

    This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

  14. Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

    PubMed Central

    Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

    2015-01-01

    This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time. PMID:25808770

  15. A digital approach for real time high-rate high-resolution radiation measurements

    NASA Astrophysics Data System (ADS)

    Gerardi, G.; Abbene, L.

    2014-12-01

    Modern spectrometers are currently developed by using digital pulse processing (DPP) systems, showing several advantages over traditional analog electronics. The aim of this work is to present digital strategies, in a time domain, for the development of real time high-rate high-resolution spectrometers. We propose a digital method, based on the single delay line (SDL) shaping technique, able to perform multi-parameter analysis with high performance even at high photon counting rates. A robust pulse shape and height analysis (PSHA), applied on single isolated time windows of the detector output waveforms, is presented. The potentialities of the proposed strategy are highlighted through both theoretical and experimental approaches. To strengthen our approach, the implementation of the method on a real-time system together with some experimental results are presented. X-ray spectra measurements with a semiconductor detector are performed both at low and high photon counting rates (up to 1.1 Mcps).

  16. Real-Time Unsteady Loads Measurements Using Hot-Film Sensors

    NASA Technical Reports Server (NTRS)

    Mangalam, Arun S.; Moes, Timothy R.

    2004-01-01

    Several flight-critical aerodynamic problems such as buffet, flutter, stall, and wing rock are strongly affected or caused by abrupt changes in unsteady aerodynamic loads and moments. Advanced sensing and flow diagnostic techniques have made possible simultaneous identification and tracking, in real-time, of the critical surface, viscosity-related aerodynamic phenomena under both steady and unsteady flight conditions. The wind tunnel study reported here correlates surface hot-film measurements of leading edge stagnation point and separation point, with unsteady aerodynamic loads on a NACA 0015 airfoil. Lift predicted from the correlation model matches lift obtained from pressure sensors for an airfoil undergoing harmonic pitchup and pitchdown motions. An analytical model was developed that demonstrates expected stall trends for pitchup and pitchdown motions. This report demonstrates an ability to obtain unsteady aerodynamic loads in real-time, which could lead to advances in air vehicle safety, performance, ride-quality, control, and health management.

  17. Real-time digital heterodyne interferometer for high resolution plasma density measurements at ISTTOK

    SciTech Connect

    Marques, T. G.; Gouveia, A.; Pereira, T.; Fortunato, J.; Carvalho, B. B.; Sousa, J.; Silva, C.; Fernandes, H.

    2008-10-15

    With the implementation of alternating discharges (ac) at the ISTTOK tokamak, the typical duration of the discharges increased from 35 to 250 ms. This time increase created the need for a real-time electron density measurement in order to control the plasma fueling. The diagnostic chosen for the real-time calculation was the microwave interferometer. The ISTTOK microwave interferometer is a heterodyne system with quadrature detection and a probing frequency of 100 GHz ({lambda}{sub 0}=3 mm). In this paper, a low-cost approach for real-time diagnostic using a digital signal programable intelligent computer embedded system is presented, which allows the measurement of the phase with a 1% fringe accuracy in less than 6 {mu}s. The system increases its accuracy by digitally correcting the offsets of the input signals and making use of a judicious lookup table optimized to improve the nonlinear behavior of the transfer curve. The electron density is determined at a rate of 82 kHz (limited by the analog to digital converter), and the data are transmitted for each millisecond although this last parameter could be much lower (around 12 {mu}s--each value calculated is transmitted). In the future, this same system is expected to control plasma actuators, such as the piezoelectric valve of the hydrogen injection system responsible for the plasma fueling.

  18. Real-time digital heterodyne interferometer for high resolution plasma density measurements at ISTTOK.

    PubMed

    Marques, T G; Gouveia, A; Pereira, T; Fortunato, J; Carvalho, B B; Sousa, J; Silva, C; Fernandes, H

    2008-10-01

    With the implementation of alternating discharges (ac) at the ISTTOK tokamak, the typical duration of the discharges increased from 35 to 250 ms. This time increase created the need for a real-time electron density measurement in order to control the plasma fueling. The diagnostic chosen for the real-time calculation was the microwave interferometer. The ISTTOK microwave interferometer is a heterodyne system with quadrature detection and a probing frequency of 100 GHz (lambda(0)=3 mm). In this paper, a low-cost approach for real-time diagnostic using a digital signal programmable intelligent computer embedded system is presented, which allows the measurement of the phase with a 1% fringe accuracy in less than 6 micros. The system increases its accuracy by digitally correcting the offsets of the input signals and making use of a judicious lookup table optimized to improve the nonlinear behavior of the transfer curve. The electron density is determined at a rate of 82 kHz (limited by the analog to digital converter), and the data are transmitted for each millisecond although this last parameter could be much lower (around 12 micros--each value calculated is transmitted). In the future, this same system is expected to control plasma actuators, such as the piezoelectric valve of the hydrogen injection system responsible for the plasma fueling.

  19. Fluorescently labeled adrenomedullin allows real-time monitoring of adrenomedullin receptor trafficking in living cells.

    PubMed

    Schönauer, Ria; Kaiser, Anette; Holze, Cathleen; Babilon, Stefanie; Köbberling, Johannes; Riedl, Bernd; Beck-Sickinger, Annette G

    2015-12-01

    The human adrenomedullin (ADM) is a 52 amino acid peptide hormone belonging to the calcitonin family of peptides, which plays a major role in the development and regulation of cardiovascular and lymphatic systems. For potential use in clinical applications, we aimed to investigate the fate of the peptide ligand after binding and activation of the adrenomedullin receptor (AM1), a heterodimer consisting of the calcitonin receptor-like receptor (CLR), a G protein-coupled receptor, associated with the receptor activity-modifying protein 2 (RAMP2). Full length and N-terminally shortened ADM peptides were synthesized using Fmoc/tBu solid phase peptide synthesis and site-specifically labeled with the fluorophore carboxytetramethylrhodamine (Tam) either by amide bond formation or copper(I)-catalyzed azide alkyne cycloaddition. For the first time, Tam-labeled ligands allowed the observation of co-internalization of the whole ligand-receptor complex in living cells co-transfected with fluorescent fusion proteins of CLR and RAMP2. Application of a fluorescent probe to track lysosomal compartments revealed that ADM together with the CLR/RAMP2-complex is routed to the degradative pathway. Moreover, we found that the N-terminus of ADM is not a crucial component of the peptide sequence in terms of AM1 internalization behavior.

  20. Application of neural network for real-time measurement of electrical resistivity in cold crucible

    NASA Astrophysics Data System (ADS)

    Votava, Pavel; Poznyak, Igor

    2017-08-01

    The article describes use of an Induction furnace with cold crucible as a tool for real-time measurement of a melted material electrical resistivity. The measurement is based on an inverse problem solution of a 2D mathematical model, possibly implementable in a microcontroller or a FPGA in a form of a neural network. The 2D mathematical model results has been provided as a training set for the neural network. At the end, the implementation results are discussed together with uncertainty of measurement, which is done by the neural network implementation itself.

  1. Real-time optical scanning system for measurement of chest volume changes during anesthesia

    NASA Astrophysics Data System (ADS)

    Duffy, Neil D.; Drummond, Gordon D.; McGowan, Steve; Dessesard, Pascal

    1991-04-01

    A low cost real time method of measuring the movement of the ribcage and abdomen during anaesthesia is described. The equipment comprises a scanning light stripe system video pre-processing electronics and a personal computer. Selected chest surface contours are measured at the rate of 2Oms per contour. Linear interpolation is used to provide contour area estimates between contour sample periods to allow chest volume to be calculated at 2Oms intervals. Results using test objects show that the equipment is able to measure volume to an accuracy of beuer than 1 with reproducibility to within 0. 3

  2. Measurement of bow tie profiles in CT scanners using a real-time dosimeter

    SciTech Connect

    Whiting, Bruce R.; Evans, Joshua D.; Williamson, Jeffrey F.; Dohatcu, Andreea C.; Politte, David G.

    2014-10-15

    Purpose: Several areas of computed tomography (CT) research require knowledge about the intensity profile of the x-ray fan beam that is introduced by a bow tie filter. This information is considered proprietary by CT manufacturers, so noninvasive measurement methods are required. One method using real-time dosimeters has been proposed in the literature. A commercially available dosimeter was used to apply that method, and analysis techniques were developed to extract fan beam profiles from measurements. Methods: A real-time ion chamber was placed near the periphery of an empty CT gantry and the dose rate versus time waveform was recorded as the x-ray source rotated about the isocenter. In contrast to previously proposed analysis methods that assumed a pointlike detector, the finite-size ion chamber received varying amounts of coverage by the collimated x-ray beam during rotation, precluding a simple relationship between the source intensity as a function of fan beam angle and measured intensity. A two-parameter model for measurement intensity was developed that included both effective collimation width and source-to-detector distance, which then was iteratively solved to minimize the error between duplicate measurements at corresponding fan beam angles, allowing determination of the fan beam profile from measured dose-rate waveforms. Measurements were performed on five different scanner systems while varying parameters such as collimation, kVp, and bow tie filters. On one system, direct measurements of the bow tie profile were collected for comparison with the real-time dosimeter technique. Results: The data analysis method for a finite-size detector was found to produce a fan beam profile estimate with a relative error between duplicate measurement intensities of <5%. It was robust over a wide range of collimation widths (e.g., 1–40 mm), producing fan beam profiles that agreed with a relative error of 1%–5%. Comparison with a direct measurement technique on

  3. Modular instrumentation system for real-time measurements and control on reciprocating engines

    NASA Technical Reports Server (NTRS)

    Rice, W. J.; Birchenough, A. G.

    1980-01-01

    An instrumentation system was developed for reciprocating engines. Among the parameters measured are the indicated mean effective pressure, or theoretical work per cycle, and the mass fraction burn rate, a measure of the combustion rate in the cylinder. These computations are performed from measured cylinder pressure and crankshaft angle and are available in real time for the experimenter. A 100 or 200 consecutive-cycle sample is analyzed to reduce the effect of cyclic variations in the engine. Data are displayed in bargraph form, and the mean and standard deviation are computed. Other instruments are also described.

  4. Carbon quantum dots-based recyclable real-time fluorescence assay for alkaline phosphatase with adenosine triphosphate as substrate.

    PubMed

    Qian, Zhaosheng; Chai, Lujing; Tang, Cong; Huang, Yuanyuan; Chen, Jianrong; Feng, Hui

    2015-03-03

    A convenient, reliable, and highly sensitive real-time assay for alkaline phosphatase (ALP) activity in the continuous and recyclable way is established on the basis of aggregation and disaggregation of carbon quantum dots (CQDs) through the competitive assay approach. CQDs and adenosine triphosphate (ATP) were used as the fluorescent indicator and substrate for ALP activity assessment, respectively. Richness of carboxyl groups on the surface of CQDs enables their severe aggregation triggered by cerium ions, which results in effective fluorescence quenching. Under the catalytic hydrolysis of ALP, ATP can be rapidly transformed to phosphate ions. Stronger affinity of phosphate ions to cerium ions than carboxyl groups is taken advantage of to achieve fluorescence recovery induced by redispersion of CQDs in the presence of ALP and ATP. Quantitative evaluation of ALP activity in a broad range from 4.6 to 383.3 U/L with the detection limit of 1.4 U/L can be realized in this way, which endows the assay with high enough sensitivity for practical detection in human serum. The assay can be used in a recyclable way for more than three times since the generated product CePO4 as a precipitate can be easily removed from the standard assay system. This strategy broadens the sensing application of fluorescent CQDs with excellent biocompatibility and provides an example based on disaggregation in optical probe development.

  5. Fluorescence Spectroscopy Approaches for the Development of a Real-Time Organophosphate Detection System Using an Enzymatic Sensor

    PubMed Central

    Carullo, Paola; Cetrangolo, Giovanni Paolo; Mandrich, Luigi; Manco, Giuseppe; Febbraio, Ferdinando

    2015-01-01

    Organophosphates are organic substances that contain a phosphoryl or a thiophosphoryl bond. They are mainly used around the world as pesticides, but can also be used as chemical warfare agents. Their detection is normally entrusted to techniques like GC- and LC-MS that, although sensitive, do not allow their identification on site and in real time. We have approached their identification by exploiting the high-affinity binding of these compounds with the esterase 2 from Alicyclobacillus acidocaldarius. Using an in silico analysis to evaluate the binding affinities of the enzyme with organophosphate inhibitors, like paraoxon, and other organophosphate compounds, like parathion, chlorpyriphos, and other organophosphate thio-derivatives, we have designed fluorescence spectroscopy experiments to study the quenching of the tryptophan residues after esterase 2 binding with the organophosphate pesticides. The changes in the fluorescence signals permitted an immediate and quantitative identification of these compounds from nano- to picomolar concentrations. A fluorescence based polarity-sensitive probe (ANS) was also employed as a means to understand the extent of the interactions involved, as well as to explore other ways to detect organophosphate pesticides. Finally, we designed a framework for the development of a biosensor that exploits fluorescence technology in combination with a sensitive and very stable bio-receptor. PMID:25671511

  6. Recent advances in real-time analysis of ionograms and ionospheric drift measurements with digisondes

    NASA Astrophysics Data System (ADS)

    Reinisch, B. W.; Huang, X.; Galkin, I. A.; Paznukhov, V.; Kozlov, A.

    2005-08-01

    Reliable long distance RF communication and transionospheric radio links depend critically on space weather, and specifically ionospheric conditions. Modern ground-based ionosondes provide space weather parameters in real-time including the vertical electron density distribution up to ˜1000 km and the velocity components of the ionospheric F region drift. A global network of digisondes distributes this information in real-time via internet connections. The quality of the automatic scaling of the echo traces in ionograms was a continuous concern ever since first attempts have been reported. The modern low-power ionosonde with ˜100 W transmitters (compared to several kilowatt for the older ionosondes) relies on more sophisticated signal processing to enhance the signal-to-noise ratio and to retrieve the essential ionospheric characteristics. Recent advances in the automatic scaling algorithm ARTIST have significantly increased the reliability of the autoscaled data, making the data, in combination with models, more useful for ionospheric now-casting. Vertical and horizontal F region drift velocities are a new real-time output of the digisondes. The “ionosonde drift” is derived from the measured Doppler frequency shift and angle of arrival of ionospherically reflected HF echoes, a method similar to that used by coherent VHF and incoherent scatter radars.

  7. Development and Test of an Infrastructure Free Real-Time Water Level Measurement System

    NASA Astrophysics Data System (ADS)

    Breuer, E. R.; Heitsenrether, R.; Hensley, W., III; Krug, W.; Wolcott, D.

    2016-02-01

    NOAA's Center for Operational Oceanographic Products and Services (CO-OPS) is responsible for developing and maintaining the National Water Level Observation Network (NWLON). NWLON consists of over 200 long term observatories that provide near real-time, 6 minute average, water level observations from locations throughout all U.S. coasts. CO-OPS continually analyzes state-of-the-art and emerging technologies to identify potential improvements in data quality and operating efficiency. NOAA, recognizing the changing conditions, anticipates a critical need for real time oceanographic and meteorological observations where traditional approaches are less feasible. CO-OPS is working on the design, development and testing of a real-time tidal measurement system, "The Hermit," for use in coastal regions. The latest prototype has recently completed a successful 3 month field test deployment in the St Andrews Sound region of Georgia, a location where relatively few long term water level records have been collected to date. The test location provided unique challenges such as having a very limited coastal infrastructure and experiencing a 7-8 foot tidal range. The Hermit consists of a bottom mounted pressure/conductivity/temperature sensor (Seabird SBE 26+) and a surface communications buoy which are linked via acoustic modems (Link Quest). The surface buoy relays data back to the CO-OPS database in near-real time using an Iridium satellite based communication system. Additionally, the buoy includes an AirMar all-in-one meteorological sensor. In addition to The Hermit deployment, three test GPS bench marks and a tide staff were installed on a nearby coastline to vertically reference water level measurements. During this deployment, The Hermit successfully provided near real-time measurements of bottom pressure, water conductivity and temperature, wind speed and direction, air temperature, and barometric pressure over the 3 month deployment. During the test period, several

  8. Global real-time dose measurements using the Automated Radiation Measurements for Aerospace Safety (ARMAS) system

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Bouwer, D.; Smart, D.; Shea, M.; Bailey, J.; Didkovsky, L.; Judge, K.; Garrett, H.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R.; Bell, D.; Mertens, C.; Xu, X.; Wiltberger, M.; Wiley, S.; Teets, E.; Jones, B.; Hong, S.; Yoon, K.

    2016-11-01

    The Automated Radiation Measurements for Aerospace Safety (ARMAS) program has successfully deployed a fleet of six instruments measuring the ambient radiation environment at commercial aircraft altitudes. ARMAS transmits real-time data to the ground and provides quality, tissue-relevant ambient dose equivalent rates with 5 min latency for dose rates on 213 flights up to 17.3 km (56,700 ft). We show five cases from different aircraft; the source particles are dominated by galactic cosmic rays but include particle fluxes for minor radiation periods and geomagnetically disturbed conditions. The measurements from 2013 to 2016 do not cover a period of time to quantify galactic cosmic rays' dependence on solar cycle variation and their effect on aviation radiation. However, we report on small radiation "clouds" in specific magnetic latitude regions and note that active geomagnetic, variable space weather conditions may sufficiently modify the magnetospheric magnetic field that can enhance the radiation environment, particularly at high altitudes and middle to high latitudes. When there is no significant space weather, high-latitude flights produce a dose rate analogous to a chest X-ray every 12.5 h, every 25 h for midlatitudes, and every 100 h for equatorial latitudes at typical commercial flight altitudes of 37,000 ft ( 11 km). The dose rate doubles every 2 km altitude increase, suggesting a radiation event management strategy for pilots or air traffic control; i.e., where event-driven radiation regions can be identified, they can be treated like volcanic ash clouds to achieve radiation safety goals with slightly lower flight altitudes or more equatorial flight paths.

  9. Determinants of shear stress-stimulated endothelial nitric oxide production assessed in real-time by 4,5-diaminofluorescein fluorescence.

    PubMed

    Qiu, W; Kass, D A; Hu, Q; Ziegelstein, R C

    2001-08-17

    The extremely short biological half-life of endothelial-derived nitric oxide (NO) has impeded real-time measurements of NO synthesis. We used the membrane-permeable fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2 DA) to study determinants of NO synthesis in bovine aortic endothelial cells (BAECs). A step increase in shear stress (SS) from 0.3 to 3.4 dyne/cm(2) triggered an increase in DAF-2 fluorescence starting 3.0 +/- 0.5 min after the flow rise and peaking at 44.7 +/- 7.2 min. This was abolished by intracellular Ca(2+) chelation, but was unaffected by blocking extracellular Ca(2+) influx or by inhibiting SS-related changes in intracellular pH. The increase in DAF-2 fluorescence occurred significantly earlier in BAECs transfected with either superoxide dismutase (SOD) or catalase (CAT), indicating concomitant reactive oxygen species (ROS) generation by SS and "competition" between ROS- and DAF-2-NO interactions. These data provide novel insights into several NO signaling determinants and reveal that DAF-2 can assess real-time SS-stimulated NO synthesis in endothelial cells. This should facilitate the analysis of NO-signaling pathways.

  10. Real-time power measurement and control for high power diode laser

    NASA Astrophysics Data System (ADS)

    Qin, Wen-bin; Liu, You-qiang; Cao, Yin-hua; Wang, Zhi-yong

    2011-06-01

    As the continual improvement of technology and beam quality, diode laser, with poor beam quality, no longer just apply to pump solid-state laser. As a kind of implement of laser materials processing, high-power diode laser has been used in manufacture, as a brand new means of laser processing. Due to the influence of inevitable unstable factors, for example, the temperature of water-cooler, the current of power supply, etc, the output power of diode laser will be unstable. And laser output power, as an important parameter, frequently affects the performance of the laser beam and the experimental results of processing, especially in the laser materials processing. Therefore, researching the real-time power measurement and control of high power diode laser has great significance, and for diode laser, it would improve performance of itself. To achieve the purpose of real-time detection, traditional measuring method, placing a power sensor behind the total-reflection mirror of laser resonant cavity, is mainly applied in the system of gas laser and solid-state laser. However, Owing to the high integration level of diode laser, traditional measuring method can't be adopted. A technique for real-time measure output power of high power diode laser is developed to improve quality of the laser in this paper. A lens placed at an angle of 45° in the system was used to sample output light of laser, and a piece of ground glass was used to uniform the beam power density, then the photoelectric detector received an optic signal and converted it into electric signal. This feeble signal was processed by amplification circuit with a filter. Finally, this detected electric signal was applied to accomplish the closed-loop control of power. The performance of power measurement and control system was tested with the 300W diode laser, and the measuring inaccuracy achieved was less than +/-1%.

  11. Real-time compensation of the refractive index of air in distance measurement.

    PubMed

    Kang, Hyun Jay; Chun, Byung Jae; Jang, Yoon-Soo; Kim, Young-Jin; Kim, Seung-Woo

    2015-10-05

    A two-color scheme of heterodyne laser interferometer is devised for distance measurements with the capability of real-time compensation of the refractive index of the ambient air. A fundamental wavelength of 1555 nm and its second harmonic wavelength of 777.5 nm are generated, with stabilization to the frequency comb of a femtosecond laser, to provide fractional stability of the order of 3.0 × 10(-12) at 1 s averaging. Achieved uncertainty is of the order of 10(-8) in measuring distances of 2.5 m without sensing the refractive index of air in adverse environmental conditions.

  12. Development of tools for real-time betatron tune measurements at the Nuclotron

    NASA Astrophysics Data System (ADS)

    Gorbachev, E. V.; Kirichenko, A. E.; Monakhov, D. V.; Romanov, S. V.; Volkov, V. I.

    2016-09-01

    A betatron tune measurement system was developed and tested at the Nuclotron. A white noise and chirp signals were used for transverse beam motion excitation. A custom FlexRIO digitizer module was developed which provides excitation signal generation for kicker electrodes and real-time signal acquisition from pickup electrodes. A high resolution FFT algorithm was implemented inside a NI PXI FPGA module, connected to digitizer. The measurement system is integrated with the NICA control system based on the TANGO Controls. Results and tests performed with the Nuclotron beam are presented.

  13. Measurement and calculation for real-time oscillation frequency and phase of the slab caster mold

    NASA Astrophysics Data System (ADS)

    Chen, Zhixin; Cai, Qizhong

    2006-11-01

    This paper presents the methods in designing and implementing real-time measurement system of oscillation parameter, based on the oscillation orderliness using in slab caster mold. From practical operation, the software can be manipulated easily and steadily. Using the software, the measurement, calculation, display, alarm and storage of oscillation state can be finished fleetly and accurately under different drawing speed. The gist is put forward in order to improve quality and quantity of slab using slab caster, judge the abrasion of drive system, the warp of leading system and other system failure.

  14. Real-time spatiotemporal measurement of ultrafast fields from multimode optical fibers

    NASA Astrophysics Data System (ADS)

    Guang, Zhe; Rhodes, Michelle; Zhu, Ping; Trebino, Rick

    2017-02-01

    Ultrashort pulses emerging from multimode optical fibers are spatiotemporally complex—the multiple fiber modes have different spatial shapes and different propagation velocities and dispersions inside fibers. To measure the complete spatiotemporal field from multimode fibers in real time, we propose and demonstrate a technique for the complete measurement of these pulses using a simple pulse characterization technique, called Spatially and Temporally Resolved Intensity and Phase Evaluation Device: Full Information from a Single Hologram (STRIPED FISH). It yields the complete electric field vs. space and time from multiple digital holograms, simultaneously recorded at different frequencies on a single camera frame.

  15. Environmental Measurement-While-Drilling System for Real-Time Field Screening of Contaminants

    SciTech Connect

    Bishop, L.B.; Lockwood, G.J.; Normann, R.A.; Selph, M.M.; Williams, C.V.

    1999-02-22

    Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of near surface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. An alternative screening technology, Environmental Measurement-While-Drilling (EMWD), could save money and valuable time by quickly distinguishing between contaminated and uncontaminated areas. Real time measurements provided by an EMWD system enable on-the-spot decisions to be made regarding sampling strategies. The system also enhances worker safety and provides the added flexibility of being able to steer a drill bit in or out of hazardous zones.

  16. Laser 3-D measuring system and real-time visual feedback for teaching and correcting breathing.

    PubMed

    Povšič, Klemen; Fležar, Matjaž; Možina, Janez; Jezeršek, Matija

    2012-03-01

    We present a novel method for real-time 3-D body-shape measurement during breathing based on the laser multiple-line triangulation principle. The laser projector illuminates the measured surface with a pattern of 33 equally inclined light planes. Simultaneously, the camera records the distorted light pattern from a different viewpoint. The acquired images are transferred to a personal computer, where the 3-D surface reconstruction, shape analysis, and display are performed in real time. The measured surface displacements are displayed with a color palette, which enables visual feedback to the patient while breathing is being taught. The measuring range is approximately 400×600×500 mm in width, height, and depth, respectively, and the accuracy of the calibrated apparatus is ±0.7 mm. The system was evaluated by means of its capability to distinguish between different breathing patterns. The accuracy of the measured volumes of chest-wall deformation during breathing was verified using standard methods of volume measurements. The results show that the presented 3-D measuring system with visual feedback has great potential as a diagnostic and training assistance tool when monitoring and evaluating the breathing pattern, because it offers a simple and effective method of graphical communication with the patient. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE).

  17. Real-time O2 measurement in a cement kiln with a TDLAS analyzer

    NASA Astrophysics Data System (ADS)

    Gao, Yanwei; Zhang, Yujun; Chen, Dong; He, Ying; You, Ku; Chen, Chen; Liu, Wenqing

    2016-10-01

    Cement kilns are the main source of atmospheric pollutants, and will consume large amounts of fuel. In order to reduce the emissions of gas pollutants and saving fuel, the combustion process inside the furnace is needed to monitor in real time. Oxygen is the main combustion-supporting gas, monitoring the oxygen concentration inside the furnace can be implemented to combustion control and optimize combustion efficiency. We developed a TDLAS analyzer for real-time oxygen concentration measurement to achieve fuel saving and gas pollutant emission reduction. We realized temperature correction algorithm using the relationship between high-temperature oxygen line strength and measurement temperature, improving the measurement accuracy of the oxygen concentration at different temperatures. We tested the analyzer and the test results show that detection limit was 0.1%, analyzer can be achieved accurate measurement of oxygen concentration, the measured oxygen concentration was 5-8%. Results were true and reliable indicated that the oxygen measuring system can be developed to achieve long-term stability operation in high-temperature environments oxygen concentration measurement.

  18. Real-time imaging of dynamic translocation of fluorescent proteins at synapses in living neurons.

    NASA Astrophysics Data System (ADS)

    De Koninck, Paul

    2003-02-01

    To understand the biology of living cells, such as the neurons in our brain, we focus on the molecular signaling interactions that proteins perform intracellularly. We have been studying the behavior of an enzyme, termed 'CaMKII', inside living neurons maintained in tissue culture. This enzyme plays a critical role in the control of synaptic transmission. Such role may involve the dynamic translocation of the enzyme at synaptic sites upon specific stimuli. To study this translocation, we use a cellular imaging technique that allows us to monitor the movement and targeting of CaMKII tagged by genetic engineering with a green fluorescent protein (GFP). We find that the enzyme translocates within seconds to synapses upon synaptic activation by neurotransmitter application. Our approach has lead to several key findings on the regulation of CaMKII translocation to the synapse and on its potential role in synaptic plasticity. However, several new advances in photonics and image analysis, which we will implement in our laboratory, will greatly help pushing the limits of our resolution of such type molecular event in living cells.

  19. Real-Time Fluorescent Polymerase Chain Reaction Detection of Phytophthora ramorum and Phytophthora pseudosyringae Using Mitochondrial Gene Regions.

    PubMed

    Tooley, Paul W; Martin, Frank N; Carras, Marie M; Frederick, Reid D

    2006-04-01

    ABSTRACT A real-time fluorescent polymerase chain reaction (PCR) detection method for the sudden oak death pathogen Phytophthora ramorum was developed based on mitochondrial DNA sequence with an ABI Prism 7700 (TaqMan) Sequence Detection System. Primers and probes were also developed for detecting P. pseudosyringae, a newly described species that causes symptoms similar to P. ramorum on certain hosts. The species-specific primer-probe systems were combined in a multiplex assay with a plant primer-probe system to allow plant DNA present in extracted samples to serve as a positive control in each reaction. The lower limit of detection of P. ramorum DNA was 1 fg of genomic DNA, lower than for many other described PCR procedures for detecting Phytophthora species. The assay was also used in a three-way multiplex format to simultaneously detect P. ramorum, P. pseudosyringae, and plant DNA in a single tube. P. ramorum was detected down to a 10(-5) dilution of extracted tissue of artificially infected rhododendron 'Cunningham's White', and the amount of pathogen DNA present in the infected tissue was estimated using a standard curve. The multiplex assay was also used to detect P. ramorum in infected California field samples from several hosts determined to contain the pathogen by other methods. The real-time PCR assay we describe is highly sensitive and specific, and has several advantages over conventional PCR assays used for P. ramorum detection to confirm positive P. ramorum finds in nurseries and elsewhere.

  20. Real-time measurement of skin erythema variation by negative compression: pilot study

    NASA Astrophysics Data System (ADS)

    Jung, Byungjo; Kim, Soobyeong; Bae, Yunjin; Kang, Heesung; Lee, Yongheum; Nelson, J. Stuart

    2012-08-01

    Skin erythema has been widely used as a diagnostic parameter in dermatology. This study describes a methodology for real-time measurement of skin erythema variation induced by negative compression. This study developed an optical measurement probe, which includes a RGB color sensor that translates in the vertical direction, with the magnitude of vertical translation dependening on the amount of skin deformation. Real-time measurement of erythema variation as a function of both negative compression and time was performed in vivo on 10 measurement sites located on the back of each of 12 volunteers who participated in this study. Negative compression was sequentially applied from -30 to -80 kPa and continuously at a constant magnitude (-80 kPa) condition. The results showed that skin erythema was uniformly induced at the measurement sites and linearly increased as a function of both negative compression and time. A wide range of individual variation was noted for skin erythema, which may be due to variations in anisotropic skin properties between volunteers. This study demonstrated the clinical feasibility of a novel optical device for skin erythema measurement. Future studies are needed to investigate the clinical applications of this device.

  1. Real-time measurement system for in-plane displacement and strain based on vision

    NASA Astrophysics Data System (ADS)

    Luo, Tao; Jin, Yi; Zhu, Ye; Zhai, Chao

    2013-08-01

    In this paper, combining optical measurement with conventional material testing machine, a real-time in-plane displacement and strain measurement system is built, which is applied to the material testing machine. This system can realize displacement and strain measurement of a large deformation sample moreover it can observe the sample crack on line. The change of displacement field is obtained through the change of center coordinate of each point of a grid lattice in the surface of the testing sample, according to two-dimensional sort coding for the grid in the traditional automated grid method, in this paper, an improved one-dimensional code method is adopted which make calculating speed much faster and the algorithm more adaptable. The measurement of the stability and precision of this system are made using the calibration board whose position precision is about 1.5 micron. The results show that the short-time stability of this system is about 0.5micron. At last, this system is used for strain measurement in a sample tension test, and the result shows that the system can acquire in-plane displacement and strain measurement results accurately and real-time, the velocity of image processing can reach 10 frame per second; or it can observe sample crack on line and storage the test process, the max velocity of observation and storage is 100 frame per second.

  2. Real-time measurement of skin erythema variation by negative compression: pilot study.

    PubMed

    Jung, Byungjo; Kim, Soobyeong; Bae, Yunjin; Kang, Heesung; Lee, Yongheum; Nelson, J Stuart

    2012-08-01

    Skin erythema has been widely used as a diagnostic parameter in dermatology. This study describes a methodology for real-time measurement of skin erythema variation induced by negative compression. This study developed an optical measurement probe, which includes a RGB color sensor that translates in the vertical direction, with the magnitude of vertical translation dependening on the amount of skin deformation. Real-time measurement of erythema variation as a function of both negative compression and time was performed in vivo on 10 measurement sites located on the back of each of 12 volunteers who participated in this study. Negative compression was sequentially applied from -30 to -80 kPa and continuously at a constant magnitude (-80 kPa) condition. The results showed that skin erythema was uniformly induced at the measurement sites and linearly increased as a function of both negative compression and time. A wide range of individual variation was noted for skin erythema, which may be due to variations in anisotropic skin properties between volunteers. This study demonstrated the clinical feasibility of a novel optical device for skin erythema measurement. Future studies are needed to investigate the clinical applications of this device.

  3. In-situ tryptophan-like fluorescence: A real-time indicator of faecal contamination in drinking water supplies.

    PubMed

    Sorensen, J P R; Lapworth, D J; Marchant, B P; Nkhuwa, D C W; Pedley, S; Stuart, M E; Bell, R A; Chirwa, M; Kabika, J; Liemisa, M; Chibesa, M

    2015-09-15

    Enteric pathogens are typically inferred from the presence of surrogate indicator organisms such as thermotolerant (faecal) coliforms (TTCs). The analysis of TTCs requires time-consuming incubation in suitable laboratories, which can limit sampling resolution, particularly during critical pollution events. Here, we demonstrate the use of in-situ fluorimeters targeting tryptophan-like compounds as a rapid, reagentless indicator of TTCs in groundwater-derived potable water supplies in Africa. A range of other common indicators of TTCs were also determined including nitrate, turbidity, and sanitary risk survey scores. Sampling was conducted during both the dry and wet seasons to investigate seasonality. Tryptophan-like fluorescence was the most effective predictor of both presence/absence and number of TTCs during both seasons. Seasonal changes in tryptophan-like fluorescence in deeper supplies suggest it is transported more efficiently through the aquifer than TTCs. Moreover, the perennial elevated concentrations in some wells suggest it is more resilient than TTCs in groundwater. Therefore tryptophan-like fluorescence could also be a better indicator of some smaller, more easily transported, and long-lived, pathogenic enteric viruses. These sensors have the potential to be included in real-time pollution alert systems for drinking water supplies throughout the world, as well as for mapping enteric pathogen risks in developing regions.

  4. Real-time intraoperative detection of breast cancer using near-infrared fluorescence imaging and Methylene Blue.

    PubMed

    Tummers, Q R J G; Verbeek, F P R; Schaafsma, B E; Boonstra, M C; van der Vorst, J R; Liefers, G-J; van de Velde, C J H; Frangioni, J V; Vahrmeijer, A L

    2014-07-01

    Despite recent developments in preoperative breast cancer imaging, intraoperative localization of tumor tissue can be challenging, resulting in tumor-positive resection margins during breast conserving surgery. Based on certain physicochemical similarities between Technetium((99m)Tc)-sestamibi (MIBI), an SPECT radiodiagnostic with a sensitivity of 83-90% to detect breast cancer preoperatively, and the near-infrared (NIR) fluorophore Methylene Blue (MB), we hypothesized that MB might detect breast cancer intraoperatively using NIR fluorescence imaging. Twenty-four patients with breast cancer, planned for surgical resection, were included. Patients were divided in 2 administration groups, which differed with respect to the timing of MB administration. N = 12 patients per group were administered 1.0 mg/kg MB intravenously either immediately or 3 h before surgery. The mini-FLARE imaging system was used to identify the NIR fluorescent signal during surgery and on post-resected specimens transferred to the pathology department. Results were confirmed by NIR fluorescence microscopy. 20/24 (83%) of breast tumors (carcinoma in N = 21 and ductal carcinoma in situ in N = 3) were identified in the resected specimen using NIR fluorescence imaging. Patients with non-detectable tumors were significantly older. No significant relation to receptor status or tumor grade was seen. Overall tumor-to-background ratio (TBR) was 2.4 ± 0.8. There was no significant difference between TBR and background signal between administration groups. In 2/4 patients with positive resection margins, breast cancer tissue identified in the wound bed during surgery would have changed surgical management. Histology confirmed the concordance of fluorescence signal and tumor tissue. This feasibility study demonstrated an overall breast cancer identification rate using MB of 83%, with real-time intraoperative guidance having the potential to alter patient management. Copyright © 2014 Elsevier Ltd. All

  5. Real-Time Intraoperative Detection of Breast Cancer using Near-infrared Fluorescence Imaging and Methylene Blue

    PubMed Central

    Tummers, Quirijn R.J.G.; Verbeek, Floris P.R.; Schaafsma, Boudewijn E.; Boonstra, Martin C.; van der Vorst, Joost R.; Liefers, Gerrit-Jan; van de Velde, Cornelis J.H.; Frangioni, John V.; Vahrmeijer, Alexander L.

    2014-01-01

    Background Despite recent developments in preoperative breast cancer imaging, intraoperative localization of tumor tissue can be challenging, resulting in tumor-positive resection margins during breast-conserving surgery. Based on certain physicochemical similarities between Technetium(99mTc)-sestamibi (MIBI), a SPECT radiodiagnostic with a sensitivity of 83–90% to detect breast cancer preoperatively, and the near-infrared (NIR) fluorophore Methylene Blue (MB), we hypothesized that MB might detect breast cancer intraoperatively using NIR fluorescence imaging. Methods Twenty-four patients with breast cancer, planned for surgical resection, were included. Patients were divided in 2 administration groups, which differed with respect to the timing of MB administration. N = 12 patients per group were administered 1.0 mg/kg MB intravenously either immediately or 3 h before surgery. The mini-FLARE imaging system was used to identify the NIR fluorescent signal during surgery and on post-resected specimens transferred to the pathology department. Results were confirmed by NIR fluorescence microscopy. Results 20/24 (83%) of breast tumors (carcinoma in N=21 and ductal carcinoma in situ in N=3) were identified in the resected specimen using NIR fluorescence imaging. Patients with non-detectable tumors were significantly older. No significant relation to receptor status or tumor grade was seen. Overall tumor-to-background ratio (TBR) was 2.4 ± 0.8. There was no significant difference between TBR and background signal between administration groups. In 2/4 patients with positive resection margins, breast cancer tissue identified in the wound bed during surgery would have changed surgical management. Histology confirmed the concordance of fluorescence signal and tumor tissue. Conclusions This feasibility study demonstrated an overall breast cancer identification rate using MB of 83%, with real-time intraoperative guidance having the potential to alter patient management. PMID

  6. Real-Time Inhibitor Recession Measurements in Two Space Shuttle Reusable Solid Rocket Motors

    NASA Technical Reports Server (NTRS)

    McWhorter, B. B.; Ewing, M. E.; Bolton, D. E.; Albrechtsen, K. U.; Earnest, T. E.; Noble, T. C.; Longaker, M.

    2003-01-01

    Real-time internal motor insulation char line recession measurements have been evaluated for two full-scale static tests of the Space Shuttle Reusable Solid Rocket Motor (RSRM). These char line recession measurements were recorded on the forward facing propellant grain inhibitors to better understand the thermal performance of these inhibitors. The RSRM propellant grain inhibitors are designed to erode away during motor operation, thus making it difficult to use post-fire observations to determine inhibitor thermal performance. Therefore, this new internal motor instrumentation is invaluable in establishing an accurate understanding of inhibitor recession versus motor operation time. The data for the first test was presented at the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (AIAA 2001-3280) in July 2001. Since that time, a second full scale static test has delivered additional real-time data on inhibitor thermal performance. The evaluation of this data is presented in this paper. The second static test, in contrast to the first test, used a slightly different arrangement of instrumentation in the inhibitors. This instrumentation has yielded a better understanding of the inhibitor time dependent inboard tip recession. Graphs of inhibitor recession profiles with time are presented. Inhibitor thermal ablation models have been created from theoretical principals. The model predictions compare favorably with data from both tests. This verified modeling effort is important to support new inhibitor designs for a five segment Space Shuttle solid rocket motor. The internal instrumentation project on RSRM static tests is providing unique opportunities for other real-time internal motor measurements that could not otherwise be directly quantified.

  7. A novel method for real-time skin impedance measurement during radiofrequency skin tightening treatments.

    PubMed

    Harth, Yoram; Lischinsky, Daniel

    2011-03-01

    The thermal effects of monopolar and bipolar radiofrequency (RF) have been proven to be beneficial in skin tightening. Nevertheless, these effects were frequently partial or unpredictable because of the uncontrolled nature of monopolar or unipolar RF and the superficial nature of energy flow for bipolar or tripolar configurations. One of the hypotheses for lack or predictability of efficacy of the first-generation RF therapy skin tightening systems is lack of adaptation of delivered power to differences in individual skin impedance. A novel multisource phase-controlled system was used (1 MHz, power range 0-65 W) for treatment and real-time skin impedance measurements in 24 patients (EndyMed PRO™; EndyMed, Cesarea, Israel). This system allows continuous real-time measurement of skin impedance delivering constant energy to the patient skin independent of changes in its impedance. More than 6000 unique skin impedance measurements on 22 patients showed an average session impedance range was 215-584 Ohm with an average of 369 Ohm (standard deviation of 49 Ohm). Analyzing individual pulses (total of 600 readings) showed a significant decrease in impedance during the pulse. These findings validate the expected differences in skin impedance between individual patients and in the same patients during the treatment pulse. Clinical study on 30 patients with facial skin aging using the device has shown high predictability of efficacy (86.7% of patients had good results or better at 3 months' follow-up [decrease of 2 or more grades in Fitzpatrick's wrinkle scale]). The real-time customization of energy according to skin impedance allows a significantly more accurate and safe method of nonablative skin tightening with more consistent and predictable results. © 2011 Wiley Periodicals, Inc.

  8. Directional wind-measurement derived from elastic backscatter lidar data in real-time

    SciTech Connect

    Moore, D.S.; White, S.W.; Karl, R.R. Jr.; Newnam, B.E.

    1996-04-01

    The development of a capability to infer wind velocities simultaneously at a number of ranges along one direction in real time is described. The elastic backscatter lidar data used was obtained using the XM94 lidar, developed by Los Alamos National Laboratory for the US Army Chemical and Biological Detection Command. In some respects this problem is simpler than measuring wind velocities on meso-meteorological scales. Other requirements, particularly high temporal fidelity, have driven the development of faster software algorithms and suggested opportunities for the evolution of the hardware.

  9. Real time drift measurement for colloidal probe atomic force microscope: a visual sensing approach

    SciTech Connect

    Wang, Yuliang Bi, Shusheng; Wang, Huimin

    2014-05-15

    Drift has long been an issue in atomic force microscope (AFM) systems and limits their ability to make long time period measurements. In this study, a new method is proposed to directly measure and compensate for the drift between AFM cantilevers and sample surfaces in AFM systems. This was achieved by simultaneously measuring z positions for beads at the end of an AFM colloidal probe and on sample surface through an off-focus image processing based visual sensing method. The working principle and system configuration are presented. Experiments were conducted to validate the real time drift measurement and compensation. The implication of the proposed method for regular AFM measurements is discussed. We believe that this technique provides a practical and efficient approach for AFM experiments requiring long time period measurement.

  10. Feasibility study on real-time γ-ray spectrum / dose measurement system

    NASA Astrophysics Data System (ADS)

    Kobayashi, Mina; Sato, Fuminobu; Kusaka, Sachie; Murata, Isao

    2017-09-01

    Recently, medical applications of radiation have been widely spread. However, exposure of medical staffs is sometimes not focused on because treatment of patients is the first priority. It is thus important to decrease exposure for them as much as possible. The purpose of this study is to develop a system which can measure energy spectrum and dose of gamma-rays at the same time in real time in medical application spots. As a result, the medical staff could be guided to aware the risk of radiation and finally the exposure dose to them could be suppressed substantially. We first decided to use a CsI(Tl) scintillator as the gamma-ray detection device. A Multi-Pixel Photon Counter (MPPC) was attached to the scintillator to detect gamma-ray signals. Pulse height spectra were measured with several standard gamma-ray sources. The detection efficiency and energy resolution were deduced from the measured results and the detection efficiency was compared with the calculation result by MCNP5. After evaluating the response function, the energy spectrum was derived with the spectrum type Bayesian estimation and the sequential Bayesian estimation procedure. From the result, it was confirmed that the sequential Bayesian estimation could be applied to real time measurement of gamma-ray energy spectrum and dose.

  11. Real-Time Measurements of Aft Dome Insulation Erosion on Space Shuttle Reusable Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    McWhorter, Bruce; Ewing, Mark; Albrechtsen, Kevin; Noble, Todd; Longaker, Matt

    2004-01-01

    Real-time erosion of aft dome internal insulation was measured with internal instrumentation on a static test of a lengthened version of the Space Shuffle Reusable Solid Rocket Motor (RSRM). This effort marks the first time that real-time aft dome insulation erosion (Le., erosion due to the combined effects of thermochemical ablation and mechanical abrasion) was measured in this kind of large motor static test [designated as Engineering Test Motor number 3 (ETM3)I. This paper presents data plots of the erosion depth versus time. The data indicates general erosion versus time behavior that is in contrast to what would be expected from earlier analyses. Engineers have long known that the thermal environment in the aft dome is severe and that the resulting aft dome insulation erosion is significant. Models of aft dome erosion involve a two-step process of computational fluid dynamics (CFD) modeling and material ablation modeling. This modeling effort is complex. The time- dependent effects are difficult to verify with only prefire and postfire insulation measurements. Nozzle vectoring, slag accumulation, and changing boundary conditions will affect the time dependence of aft dome erosion. Further study of this data and continued measurements on future motors will increase our understanding of the aft dome flow and erosion environment.

  12. Flexible imaging payload for real-time fluorescent biological imaging in parabolic, suborbital and space analog environments

    NASA Astrophysics Data System (ADS)

    Bamsey, Matthew T.; Paul, Anna-Lisa; Graham, Thomas; Ferl, Robert J.

    2014-10-01

    utilized to assess, in real-time, the response of plants to novel environments including various spaceflight analogs, including several parabolic flight environments as well as hypobaric plant growth chambers. Basic performance results obtained under these operational environments, as well as laboratory-based tests are described. The Flex Imager has also been designed to be compatible with emerging suborbital platforms.

  13. Using RADFET for the real-time measurement of gamma radiation dose rate

    NASA Astrophysics Data System (ADS)

    Andjelković, Marko S.; Ristić, Goran S.; Jakšić, Aleksandar B.

    2015-02-01

    RADFETs (RADiation sensitive Field Effect Transistors) are integrating ionizing radiation dosimeters operating on the principle of conversion of radiation-induced threshold voltage shift into absorbed dose. However, one of the major drawbacks of RADFETs is the inability to provide the information on the dose rate in real-time using the conventional absorbed dose measurement technique. The real-time monitoring of dose rate and absorbed dose can be achieved with the current mode dosimeters such as PN and PIN diodes/photodiodes, but these dosimeters have some limitations as absorbed dose meters and hence they are often not a suitable replacement for RADFETs. In that sense, this paper investigates the possibility of using the RADFET as a real-time dose rate meter so that it could be applied for simultaneous online measurement of the dose rate and absorbed dose. A RADFET sample, manufactured by Tyndall National Institute, Cork, Ireland, was tested as a dose rate meter under gamma irradiation from a Co-60 source. The RADFET was configured as a PN junction, such that the drain, gate and source terminals were grounded, while the radiation-induced current was measured at the bulk terminal, whereby the bulk was successively biased with 0 , 10 , 20  and 30 V. In zero-bias mode the radiation-induced current was unstable, but in the biased mode the current response was stable for the investigated dose rates from 0.65  to 32.1 Gy h-1 and up to the total absorbed dose of 25 Gy. The current increased with the dose rate in accordance with the power law, whereas the sensitivity of the current read-out was linear with respect to the applied bias voltage. Comparison with previously analyzed PIN photodiodes has shown that the investigated RADFET is competitive with PIN photodiodes as a gamma radiation dose rate meter and therefore has the potential to be employed for the real-time monitoring of the dose rate and absorbed dose.

  14. The measurement of 3-D asymmetric temperature field by using real time laser interferometric tomography

    NASA Astrophysics Data System (ADS)

    Wang, Dezhong; Zhuang, Tiange

    2001-09-01

    A real time nondestructive temperature measurement technique based on laser holographic interference tomography technique is presented. An He-Ne laser is used as light source, and a CCD video camera is used to grab the interferogram. This laser holographic tomography technique is applied to the measurement of the temperature fields generated by two heated rods. Since data error is inevitable in engineering measurement, it is necessary to study the reconstruction techniques for reconstructing the temperature field. Three techniques including convolution back projection (CBP), algebra reconstruction technique (ART) and simultaneous iterative reconstruction technique (SIRT) are studied. Based on the reconstruction techniques and experimental situation, ART is used to reconstruct the asymmetric temperature fields. The thermocouples are used to measure the temperatures of the two heated rods. Comparing the reconstructed result with the measured temperature value, a satisfactory result is obtained.

  15. Spectroscopic imaging ellipsometry: real-time measurement of single, intact wood pulp fibers

    NASA Astrophysics Data System (ADS)

    Ye, Chun

    2006-12-01

    A nondestructive method based on spectroscopic ellipsometry has been developed and demonstrated for the real-time measurement of a single pulp fiber's microfibril angle and phase retardation, with the latter proportional to the cell wall thickness. The method uses an optical arrangement insensitive to the sample's orientation in combination with a proper spectral analysis of the sample's image. The optical arrangement and the measurement principle of the method are described. To test the new method, equipment functioning as a spectroscopic imaging ellipsometer was constructed according to the arrangement, and measurements were carried out in which single pulp fibers and ordinary wave plates were measured. The test measurements and results are described and presented.

  16. A Real-Time Measurement System for Long-Life Flood Monitoring and Warning Applications

    PubMed Central

    Marin-Perez, Rafael; García-Pintado, Javier; Gómez, Antonio Skarmeta

    2012-01-01

    A flood warning system incorporates telemetered rainfall and flow/water level data measured at various locations in the catchment area. Real-time accurate data collection is required for this use, and sensor networks improve the system capabilities. However, existing sensor nodes struggle to satisfy the hydrological requirements in terms of autonomy, sensor hardware compatibility, reliability and long-range communication. We describe the design and development of a real-time measurement system for flood monitoring, and its deployment in a flash-flood prone 650 km2 semiarid watershed in Southern Spain. A developed low-power and long-range communication device, so-called DatalogV1, provides automatic data gathering and reliable transmission. DatalogV1 incorporates self-monitoring for adapting measurement schedules for consumption management and to capture events of interest. Two tests are used to assess the success of the development. The results show an autonomous and robust monitoring system for long-term collection of water level data in many sparse locations during flood events. PMID:22666028

  17. A real-time measurement system for long-life flood monitoring and warning applications.

    PubMed

    Marin-Perez, Rafael; García-Pintado, Javier; Gómez, Antonio Skarmeta

    2012-01-01

    A flood warning system incorporates telemetered rainfall and flow/water level data measured at various locations in the catchment area. Real-time accurate data collection is required for this use, and sensor networks improve the system capabilities. However, existing sensor nodes struggle to satisfy the hydrological requirements in terms of autonomy, sensor hardware compatibility, reliability and long-range communication. We describe the design and development of a real-time measurement system for flood monitoring, and its deployment in a flash-flood prone 650 km(2) semiarid watershed in Southern Spain. A developed low-power and long-range communication device, so-called DatalogV1, provides automatic data gathering and reliable transmission. DatalogV1 incorporates self-monitoring for adapting measurement schedules for consumption management and to capture events of interest. Two tests are used to assess the success of the development. The results show an autonomous and robust monitoring system for long-term collection of water level data in many sparse locations during flood events.

  18. Design and implementation of real-time LED spatial radiance measurement systems

    NASA Astrophysics Data System (ADS)

    Chang, Gao-Wei; Yeh, Zong-Mu; Liao, Chia-Cheng

    2007-02-01

    Light-emitting diodes (LEDs) have been recognized as a generation of new light sources because they possess the properties of energy-saving, environmental protection, long lifetime, and those lacking in conventional lighting. To satisfy the requirements for different applications (e.g., for large-scale displays), determining the spatial radiances of LEDs is important to identifying their viewing angle and utilizing their lighting efficiency. The objective of this paper is to build up a real-time spatial radiance measurement system for LEDs, on the basis of digital signal processing (DSP) techniques. In this paper, the system analysis is given to show the feasibility of this work. Two primary subsystems are devised to perform the real-time measurements. First, in the optoelectronic sensing and signal processing subsystem, a wide-bandwidth photodiode sensing circuit is employed to acquire optical signals at a high speed, and an automatic gain control (AGC) circuit is designed to increase the measurement range. To support high-speed data processing, a DSP-based platform is developed in the subsystem. Second, a light-source rotation scheme is used in the optomechanical subsystem. For performance evaluations, we adopt a standard calibrating light source to test and verify our system. Experimental results indicate that the proposed system gives satisfactory results.

  19. GPU-assisted real-time three dimensional shape measurement by speckle-embedded fringe

    NASA Astrophysics Data System (ADS)

    Feng, Shijie; Chen, Qian; Zuo, Chao

    2015-07-01

    This paper presents a novel two-frame method of fringe projection for real-time, accurate and unambiguous threedimensional shape measurement. One of the used frames is a speckle pattern and the other one is a composite image which is fused by that speckle image and sinusoidal fringes. The sinusoidal component is used to retrieve the wrapped phase map. The frame of the speckle is employed to remove the phase ambiguity for the reconstruction of the absolute depth. Compared with traditional multi-frequency phase-shifting methods, the proposed scheme is of much lower sensitivity to movements as the result of the reduced number of used patterns. Moreover, its measuring precision is very close to that of the phase-shifting method, which indicates the method is of high accuracy. To process data in real time, a CUDA-enabled Graphics Processing Unit (GPU) is introduced to accelerate the computations of phase and depth. With our system, measurements can be performed at 21 frames per second with a resolution of 307K points per frame.

  20. Spatial filtering velocimetry for real-time out-of-plane displacement measurements

    NASA Astrophysics Data System (ADS)

    Olesen, A. S.; Yura, H. T.; Jakobsen, M. L.

    2016-04-01

    We probe the dynamics of objective laser speckles as the axial distance between the object and the observation plane changes. With the purpose of measuring out-of-plane motion in real time, we apply optical spatial filtering velocimetry to the speckle dynamics. To achieve this, a rotationally symmetric spatial filter is designed. The spatial filter converts the speckle dynamics into a photocurrent with a quasi-sinusoidal response to the out-of-plane motion. The selectivity of the sensor relates directly to the uncertainty on sensor measurements. The selectivity most be derived from a temporal power spectrum of the photocurrent produced by this filter. This main contribution of this paper is a model, which describe the selectivity of the sensor, applied to speckle dynamics generated by an object moving out-of-plane. To motivate our interest in these filters we also present an all optical element which implements the spatial filter and experimentally demonstrate the ability of the technology to obtain displacement measurements of a vibrating object in real-time.

  1. Real-time analysis of multi-laser-beam fluorescence for timed control of laser tweezers in a microfluidic cell-sorting device

    NASA Astrophysics Data System (ADS)

    Davis, Lloyd M.; Lubbeck, Jennifer L.; Dean, Kevin M.; Palmer, Amy E.; Jimenez, Ralph

    2012-10-01

    We have developed a microfluidic cell sorter for mammalian cells expressing intrinsic fluorescent proteins that enables selection of cells with proteins that have enhanced photophysical properties, such as reduced fluorescence photobleaching and/or reversible dark state conversion. Previous ensemble imaging studies have used an acousto-optic modulator (AOM) to provide millisecond pulsed laser illumination for in vivo assays that distinguish reversible darkstate conversion from irreversible photobleaching. However, in the sorter, cells are hydrodynamically focused into a stream, which flows through a series of 4 or 8 line-focused, continuous, 532 nm laser beams, such that each cell experiences a similar millisecond modulated excitation. The amplitude and timing of the fluorescence response from each of the beams are measured by a red-sensitive photomultiplier and analyzed in real time to separately determine initial fluorescence brightness and photobleaching characteristics. In addition, each cell's flow speed is found from its time of passage through the beams, and if the analysis results are within adjustable limits, a 1064 nm optical trap beam is switched on and moved along an intersecting trajectory at a matching speed, so that the cell becomes deflected by the optical gradient forces towards another exit channel of the microfluidic device. The optical sorting of cells is similar to that demonstrated by others, except that the motion of the trap beam is achieved using a piezo mirror under computer control, rather than an AOM; also, rather than a single-beam brightness measure using a hardwired circuit, a more complex multi-beam analysis is performed in software using the Real-Time module of LabView (National Instruments) on a separate computer to achieve deterministic timing and low latency. The software displays updated statistics of the sort, obtained by counting cells that pass through an extra laser beam in the exit channel. A mixture of cells expressing

  2. Monitoring and simulating real-time electric power system operation with phasor measurements

    SciTech Connect

    Phadke, A.G.; Thorp, J.S.

    1995-01-01

    In this research project, two important results have been achieved. The concept of generator axis load flow has been developed more fully, and has been tested through simulations on the 39-bus system (with 10 generators). Generator axis load flow is a load flow calculation which views the entire network from a few retained buses such as the internal nodes of the generators. As these nodes can be indirectly monitored in real time through phasor measurements of generator terminal quantities, it becomes possible to track and predict the behavior of the entire network from these few observation points. This is extremely valuable in the task of predicting network instability in real time. The task of instability prediction of a multi-machine power system is one of the most difficult analytical exercises. We investigated two of the most promising approaches: the extended equal area method, and the transient energy function method. Although both of these methods work well in many instances, we have shown that in other cases, the predictions made by the two methods are incorrect. The failure of the methods can be traced to their inability to deal with the behavior of the system after the first turning point of the motor swing curves. Instead of using these methods, we propose the direct integration of the machine swing equations following the start of a disturbance. Coupled with the generator aids load flow developed above, and using the high speed computers available now, we show that for systems of significant size (39 bus system), accurate predictions through direct computation are possible. The report also includes results on computational efficiency of the method of faster-than-real-time integration using machine equations and the generator aids load flow. It is anticipated that this technique will be useful in most practical applications in power system control centers of the future.

  3. Real time M2 and beam parameter product measurement using GigE CMOS sensors

    NASA Astrophysics Data System (ADS)

    Scaggs, Michael; Haas, Gil

    2016-03-01

    The ISO 11146-1 standard for measurement of a laser's M-square requires the minimum measurement of five (5) spatial profiles within the first Rayleigh range and an addition five (5) outside the second Rayleigh range. The first five spatial profiles within the first Rayleigh range establish the beam waist and its location; the second five beyond the second Rayleigh range establish the divergence or convergence from the focusing lens for the M-square computation. The majority of methods used to date are all time averaged and as such are incapable of a real time M-square measurement. We present an ISO 11146-1 compliant method for measuring single shot M-square or beam parameter product values or the measurement of continuous wave sources at rates greater than five frames per second utilizing a pair of GigE based CMOS sensors. One GigE CMOS sensor is setup to measure the minimum of five spots within the first Rayleigh range for the establishment of the beam waist and its location. A second GigE CMOS sensor is setup to measure the five spatial profiles beyond the second Rayleigh range for the determination of the beam divergence from the focusing lens. Both GigE cameras utilize optics that passively create multiple spatial time slices of the beam and superimpose these time slices on the CMOS sensor in real time resulting in the ability to make single pulse measurements or continuous wave measurements at speeds of greater than five frames per second with full ISO 11146-1 compliance.

  4. Hands-free, Wireless Goggles for Near-infrared Fluorescence and Real-time Image-guided Surgery

    PubMed Central

    Liu, Yang; Bauer, Adam Q.; Akers, Walter; Sudlow, Gail; Liang, Kexian; Shen, Duanwen; Berezin, Mikhail; Culver, Joseph P.; Achilefu, Samuel

    2011-01-01

    Background Current cancer management faces several challenges, including the occurrence of residual tumor after resection, the use of radioactive materials or high concentrations of blue dyes for sentinel lymph node (SLN) biopsy, and use of bulky systems in surgical suites for image guidance. To overcome these limitations, we developed a real-time intraoperative imaging device that, when combined with near infrared (NIR) fluorescent molecular probes, can aid identification of tumor margins, guide surgical resections, map SLNs, and transfer acquired data wirelessly for remote analysis. Methods We developed a new compact, wireless, wearable, and battery-operated device that allows hands-free operation by surgeons. A CCD-based consumer-grade night vision viewer was used to develop the detector portion of the device and the light source portion was developed from a compact headlamp. This piece was retrofitted to provide both NIR excitation and white light illumination simultaneously. Wireless communication was enabled by integrating a battery-operated miniature radio-frequency video transmitter into the system. We applied the device in several types of oncologic surgical procedures in murine models, including SLN mapping, fluorescence-guided tumor resection, and surgery under remote expert guidance. Results Unlike conventional imaging instruments, the device directly displays fluorescence information on its eyepiece. When employed in SLN mapping, the locations of SLNs were clearly visualized, even with tracer level dosing of a NIR fluorescent dye, indocyanine green. When utilized in tumor resection, tumor margins and small nodules not visible to the naked eye were readily visualized. In a simulated point-of-care setting, tumors were successfully located and removed under remote guidance using the wireless feature of the device. Importantly, the total cost of this prototype system ($1200) is significantly lower than existing imaging instruments. Conclusion Our results

  5. Real-time analysis of human immunodeficiency virus type 1 Env-mediated membrane fusion by fluorescence resonance energy transfer.

    PubMed

    Furuta, Rika A; Nishikawa, Masao; Fujisawa, Jun-ichi

    2006-02-01

    Human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env)-mediated membrane fusion occurs as a sequence of events that is triggered by CD4 binding to the Env gp120 subunit. In this study, we analyzed the dynamics of Env-mediated membrane fusion at the single-cell level using fluorescent fusion proteins and confocal laser fluorescent microscopy. Either enhanced cyan or yellow fluorescent protein (CFP and YFP, respectively) was fused to the end of the cytoplasmic regions of the HIV-1 receptors (CD4 and CCR5) and Env proteins. Real-time imaging of membrane fusion mediated by these recombinant proteins revealed that the kinetics of fusion in our system was faster than that previously reported. Analysis of the receptor interaction by fluorescence resonance energy transfer (FRET) at the single-cell level demonstrated a tendency for oligomerization of CD4-CD4, but not of CD4-CCR5, in the absence of Env-expressing cells. However, when Env-expressing cells attached to the receptor cells, FRET produced by CD4-CCR5 interaction was increased; the FRET intensity began to decline before the formation of the fusion pore. These changes in FRET may represent the temporal association of these receptors, triggered by gp120 binding, and their dissociation during the formation of the fusion pore. In addition, the FRET analysis of receptor interactions in the presence of fusion inhibitors showed that not only inhibitors acting on CCR5 but also the gp41-derived peptide T-20 interfered with CD4-CCR5 interaction during fusion. These data suggest that T-20 could affect the formation of Env-receptors complexes during the membrane fusion.

  6. Near real-time field measurements of δ13C in CO2 from volcanoes

    NASA Astrophysics Data System (ADS)

    Stix, John; Lucic, Gregor; Malowany, Kalina

    2017-08-01

    This paper describes the operation and application of a portable cavity ring-down spectrometer (CRDS) designed to measure the isotopic composition of carbon dioxide. The instrument is capable of measuring δ13C for CO2 concentrations ranging from atmospheric (400 ppm) to 100%, at precisions and accuracies that are comparable to laboratory-based gas source mass spectrometers. This flexibility and portability are ideal for applications on active volcanoes, and it is now possible to obtain isotopic measurements on a near real-time basis. We show applications of the CRDS for soil gases on volcanoes and in calderas, for characterizing the isotopic composition of a volcanic plume, and for measuring the temporal variability of δ13C in the atmosphere. Future directions hold the potential to use volcanic gas isotopes for monitoring purposes, and to combine different isotopic systems to reveal the source or sources of gas.

  7. Obtaining Reliable Predictions of Terrestrial Energy Coupling From Real-Time Solar Wind Measurements

    NASA Technical Reports Server (NTRS)

    Weimer, Daniel R.

    2002-01-01

    Measurements of the interplanetary magnetic field (IMF) from the ACE (Advanced Composition Explorer), Wind, IMP-8 (Interplanetary Monitoring Platform), and Geotail spacecraft have revealed that the IMF variations are contained in phase planes that are tilted with respect to the propagation direction, resulting in continuously variable changes in propagation times between spacecraft, and therefore, to the Earth. Techniques for using 'minimum variance analysis' have been developed in order to be able to measure the phase front tilt angles, and better predict the actual propagation times from the L1 orbit to the Earth, using only the real-time IMF measurements from one spacecraft. The use of empirical models with the IMF measurements at L1 from ACE (or future satellites) for predicting 'space weather' effects has also been demonstrated.

  8. Real-Time Measurement of Material Elastic Properties in a High Gamma Irradiation Environment

    SciTech Connect

    Ken Telschow; Rob Schley; Dave Cottle

    2006-05-01

    This paper describes the first noncontact elastic vibration measurements of an object in a high gamma radiation field. Using a laser-coupled resonant ultrasound technique, the vibration modes of an Inconel hollow capped cylinder were measured as the gamma radiation field was increased to 104 Gy/h. This measurement technique allowed shifts in the resonant frequency of the sample’s vibration modes to be tracked over a 170-h period. The vibration mode frequencies changed in a manner consistent with the temperature dependence of the elastic stiffness coefficients of the material. These results demonstrate the efficacy of the laser approach for real-time resonant ultrasound measurements in this severely hostile nuclear environment.

  9. Real-time brain activity measurement and signal processing system using highly sensitive MI sensor

    NASA Astrophysics Data System (ADS)

    Wang, Kewang; Cai, Changmei; Yamamoto, Michiharu; Uchiyama, Tsuyoshi

    2017-05-01

    Superconducting Quantum Interference Devices (SQUIDs) are the most used sensor to detect the extremely weak magnetic field of brain. However, the sensor heads need to be kept at very low temperature to maintain superconductivity, and that makes the devices large-scale and inconvenient. In order to measure brain activity in normal environment, we had constructed a measurement system based on highly sensitive Magneto-Impedance (MI) sensor, and reported the study of measuring Auditory Evoked Field (AEF) brain waves. In this study, the system was improved, and the sensor signals can be processed in real-time to monitor brain activity. We use this system to measure the alpha rhythm in the occipital region and the Event-Related Field (ERF) P300 in the frontal, the parietal and both the temporal regions.

  10. Using Indirect Turbulence Measurements for Real-Time Parameter Estimation in Turbulent Air

    NASA Technical Reports Server (NTRS)

    Martos, Borja; Morelli, Eugene A.

    2012-01-01

    The use of indirect turbulence measurements for real-time estimation of parameters in a linear longitudinal dynamics model in atmospheric turbulence was studied. It is shown that measuring the atmospheric turbulence makes it possible to treat the turbulence as a measured explanatory variable in the parameter estimation problem. Commercial off-the-shelf sensors were researched and evaluated, then compared to air data booms. Sources of colored noise in the explanatory variables resulting from typical turbulence measurement techniques were identified and studied. A major source of colored noise in the explanatory variables was identified as frequency dependent upwash and time delay. The resulting upwash and time delay corrections were analyzed and compared to previous time shift dynamic modeling research. Simulation data as well as flight test data in atmospheric turbulence were used to verify the time delay behavior. Recommendations are given for follow on flight research and instrumentation.

  11. Complexity-Measure-Based Sequential Hypothesis Testing for Real-Time Detection of Lethal Cardiac Arrhythmias

    NASA Astrophysics Data System (ADS)

    Chen, Szi-Wen

    2006-12-01

    A novel approach that employs a complexity-based sequential hypothesis testing (SHT) technique for real-time detection of ventricular fibrillation (VF) and ventricular tachycardia (VT) is presented. A dataset consisting of a number of VF and VT electrocardiogram (ECG) recordings drawn from the MIT-BIH database was adopted for such an analysis. It was split into two smaller datasets for algorithm training and testing, respectively. Each ECG recording was measured in a 10-second interval. For each recording, a number of overlapping windowed ECG data segments were obtained by shifting a 5-second window by a step of 1 second. During the windowing process, the complexity measure (CM) value was calculated for each windowed segment and the task of pattern recognition was then sequentially performed by the SHT procedure. A preliminary test conducted using the database produced optimal overall predictive accuracy of[InlineEquation not available: see fulltext.]. The algorithm was also implemented on a commercial embedded DSP controller, permitting a hardware realization of real-time ventricular arrhythmia detection.

  12. Laser optoacoustic technique for real-time measurement of thermal damage in tissues

    NASA Astrophysics Data System (ADS)

    Esenaliev, Rinat O.; Larina, Irina V.; Larin, Kirill V.; Motamedi, Massoud; Karabutov, Alexander A.; Oraevsky, Alexander A.

    1999-05-01

    Optoacoustic monitoring of thermally-induced damage in tissues in real time is proposed as a mean for controlling the extent of tissue coagulation in human organs, such as liver, prostate, myocardium, breast, and brain. This technique can potentially provide fast and accurate feedback information during tumor thermal coagulation by interstitial delivery of laser, ultrasonic, radiofrequency, and microwave radiation or conductive and convective heating. Amplitude and temporal characteristics of optoacoustic signals are dependent on optical and thermophysical properties of tissues. Changes in tissue optical properties during coagulation can be detected by measuring and analyzing the amplitude and temporal characteristics of the optoacoustic signals. We performed studies on optoacoustic monitoring of coagulation by CW Nd:YAG laser interstitial irradiation and conductive heating. Q-switched Nd:YAG laser pulses were used as a probing radiation to obtain optoacoustic pressure profiles and images. Our preliminary studies suggest that the laser optoacoustic technique is capable of detecting thermally-induced changes in optical properties of liver, myocardium, and prostate. The major merits of the laser optoacoustic monitoring of tissue coagulation include high contrast provided by changes in tissue optical properties, capability to perform real-time measurements, and high spatial resolution.

  13. Optimized quantum sensing with a single electron spin using real-time adaptive measurements

    NASA Astrophysics Data System (ADS)

    Bonato, C.; Blok, M. S.; Dinani, H. T.; Berry, D. W.; Markham, M. L.; Twitchen, D. J.; Hanson, R.

    2016-03-01

    Quantum sensors based on single solid-state spins promise a unique combination of sensitivity and spatial resolution. The key challenge in sensing is to achieve minimum estimation uncertainty within a given time and with high dynamic range. Adaptive strategies have been proposed to achieve optimal performance, but their implementation in solid-state systems has been hindered by the demanding experimental requirements. Here, we realize adaptive d.c. sensing by combining single-shot readout of an electron spin in diamond with fast feedback. By adapting the spin readout basis in real time based on previous outcomes, we demonstrate a sensitivity in Ramsey interferometry surpassing the standard measurement limit. Furthermore, we find by simulations and experiments that adaptive protocols offer a distinctive advantage over the best known non-adaptive protocols when overhead and limited estimation time are taken into account. Using an optimized adaptive protocol we achieve a magnetic field sensitivity of 6.1 ± 1.7 nT Hz-1/2 over a wide range of 1.78 mT. These results open up a new class of experiments for solid-state sensors in which real-time knowledge of the measurement history is exploited to obtain optimal performance.

  14. Real-time high-resolution heterodyne-based measurements of spectral dynamics in fibre lasers

    NASA Astrophysics Data System (ADS)

    Sugavanam, Srikanth; Fabbri, Simon; Le, Son Thai; Lobach, Ivan; Kablukov, Sergey; Khorev, Serge; Churkin, Dmitry

    2016-03-01

    Conventional tools for measurement of laser spectra (e.g. optical spectrum analysers) capture data averaged over a considerable time period. However, the generation spectrum of many laser types may involve spectral dynamics whose relatively fast time scale is determined by their cavity round trip period, calling for instrumentation featuring both high temporal and spectral resolution. Such real-time spectral characterisation becomes particularly challenging if the laser pulses are long, or they have continuous or quasi-continuous wave radiation components. Here we combine optical heterodyning with a technique of spatio-temporal intensity measurements that allows the characterisation of such complex sources. Fast, round-trip-resolved spectral dynamics of cavity-based systems in real-time are obtained, with temporal resolution of one cavity round trip and frequency resolution defined by its inverse (85 ns and 24 MHz respectively are demonstrated). We also show how under certain conditions for quasi-continuous wave sources, the spectral resolution could be further increased by a factor of 100 by direct extraction of phase information from the heterodyned dynamics or by using double time scales within the spectrogram approach.

  15. Real-time high-resolution heterodyne-based measurements of spectral dynamics in fibre lasers.

    PubMed

    Sugavanam, Srikanth; Fabbri, Simon; Le, Son Thai; Lobach, Ivan; Kablukov, Sergey; Khorev, Serge; Churkin, Dmitry

    2016-03-17

    Conventional tools for measurement of laser spectra (e.g. optical spectrum analysers) capture data averaged over a considerable time period. However, the generation spectrum of many laser types may involve spectral dynamics whose relatively fast time scale is determined by their cavity round trip period, calling for instrumentation featuring both high temporal and spectral resolution. Such real-time spectral characterisation becomes particularly challenging if the laser pulses are long, or they have continuous or quasi-continuous wave radiation components. Here we combine optical heterodyning with a technique of spatio-temporal intensity measurements that allows the characterisation of such complex sources. Fast, round-trip-resolved spectral dynamics of cavity-based systems in real-time are obtained, with temporal resolution of one cavity round trip and frequency resolution defined by its inverse (85 ns and 24 MHz respectively are demonstrated). We also show how under certain conditions for quasi-continuous wave sources, the spectral resolution could be further increased by a factor of 100 by direct extraction of phase information from the heterodyned dynamics or by using double time scales within the spectrogram approach.

  16. Strengthening HIV surveillance: measurements to track the epidemic in real time.

    PubMed

    Buthelezi, Usangiphile E; Davidson, Candace L; Kharsany, Ayesha Bm

    2016-07-01

    Surveillance for HIV as a public health initiative requires timely, detailed and robust data to systematically understand burden of infection, transmission patterns, direct prevention efforts, guide funding, identify new infections and predict future trends in the epidemic. The methods for HIV surveillance have evolved to reliably track the epidemic and identify new infections in real time. Initially HIV surveillance relied primarily on the reporting of AIDS cases followed by measuring antibodies to HIV to determine prevalence in key populations. With the roll-out of antiretroviral therapy (ART) resulting in better survival and the corresponding increase in HIV prevalence, the landscape of surveillance shifted further to track HIV prevalence and incidence within the context of programmes. Recent developments in laboratory assays that potentially measure and differentiate recent versus established HIV infection offer a cost-effective method for the rapid estimation of HIV incidence. These tests continue to be validated and are increasingly useful in informing the status of the epidemic in real time. Surveillance of heterogeneity of infections contributing to sub-epidemics requires methods to identify affected populations, density, key geographical locations and phylogenetically linked or clustered infections. Such methods could provide a nuanced understanding of the epidemic and prioritise prevention efforts to those most vulnerable. This paper brings together recent developments and challenges facing HIV surveillance, together with the application of newer assays and methods to fast-track the HIV prevention and treatment response.

  17. Toward Real-Time Automated Detection of Turns during Gait Using Wearable Inertial Measurement Units

    PubMed Central

    Novak, Domen; Goršič, Maja; Podobnik, Janez; Munih, Marko

    2014-01-01

    Previous studies have presented algorithms for detection of turns during gait using wearable sensors, but those algorithms were not built for real-time use. This paper therefore investigates the optimal approach for real-time detection of planned turns during gait using wearable inertial measurement units. Several different sensor positions (head, back and legs) and three different detection criteria (orientation, angular velocity and both) are compared with regard to their ability to correctly detect turn onset. Furthermore, the different sensor positions are compared with regard to their ability to predict the turn direction and amplitude. The evaluation was performed on ten healthy subjects who performed left/right turns at three amplitudes (22, 45 and 90 degrees). Results showed that turn onset can be most accurately detected with sensors on the back and using a combination of orientation and angular velocity. The same setup also gives the best prediction of turn direction and amplitude. Preliminary measurements with a single amputee were also performed and highlighted important differences such as slower turning that need to be taken into account. PMID:25310470

  18. Real-time high-resolution heterodyne-based measurements of spectral dynamics in fibre lasers

    PubMed Central

    Sugavanam, Srikanth; Fabbri, Simon; Le, Son Thai; Lobach, Ivan; Kablukov, Sergey; Khorev, Serge; Churkin, Dmitry

    2016-01-01

    Conventional tools for measurement of laser spectra (e.g. optical spectrum analysers) capture data averaged over a considerable time period. However, the generation spectrum of many laser types may involve spectral dynamics whose relatively fast time scale is determined by their cavity round trip period, calling for instrumentation featuring both high temporal and spectral resolution. Such real-time spectral characterisation becomes particularly challenging if the laser pulses are long, or they have continuous or quasi-continuous wave radiation components. Here we combine optical heterodyning with a technique of spatio-temporal intensity measurements that allows the characterisation of such complex sources. Fast, round-trip-resolved spectral dynamics of cavity-based systems in real-time are obtained, with temporal resolution of one cavity round trip and frequency resolution defined by its inverse (85 ns and 24 MHz respectively are demonstrated). We also show how under certain conditions for quasi-continuous wave sources, the spectral resolution could be further increased by a factor of 100 by direct extraction of phase information from the heterodyned dynamics or by using double time scales within the spectrogram approach. PMID:26984634

  19. In situ real-time measurement of physical characteristics of airborne bacterial particles

    NASA Astrophysics Data System (ADS)

    Jung, Jae Hee; Lee, Jung Eun

    2013-12-01

    Bioaerosols, including aerosolized bacteria, viruses, and fungi, are associated with public health and environmental problems. One promising control method to reduce the harmful effects of bioaerosols is thermal inactivation via a continuous-flow high-temperature short-time (HTST) system. However, variations in bioaerosol physical characteristics - for example, the particle size and shape - during the continuous-flow inactivation process can change the transport properties in the air, which can affect particle deposition in the human respiratory system or the filtration efficiency of ventilation systems. Real-time particle monitoring techniques are a desirable alternative to the time-consuming process of microscopic analysis that is conventionally used in sampling and particle characterization. Here, we report in situ real-time optical scattering measurements of the physical characteristics of airborne bacteria particles following an HTST process in a continuous-flow system. Our results demonstrate that the aerodynamic diameter of bacterial aerosols decreases when exposed to a high-temperature environment, and that the shape of the bacterial cells is significantly altered. These variations in physical characteristics using optical scattering measurements were found to be in agreement with the results of scanning electron microscopy analysis.

  20. A robust adaptive denoising framework for real-time artifact removal in scalp EEG measurements

    NASA Astrophysics Data System (ADS)

    Kilicarslan, Atilla; Grossman, Robert G.; Contreras-Vidal, Jose Luis

    2016-04-01

    Objective. Non-invasive measurement of human neural activity based on the scalp electroencephalogram (EEG) allows for the development of biomedical devices that interface with the nervous system for scientific, diagnostic, therapeutic, or restorative purposes. However, EEG recordings are often considered as prone to physiological and non-physiological artifacts of different types and frequency characteristics. Among them, ocular artifacts and signal drifts represent major sources of EEG contamination, particularly in real-time closed-loop brain-machine interface (BMI) applications, which require effective handling of these artifacts across sessions and in natural settings. Approach. We extend the usage of a robust adaptive noise cancelling (ANC) scheme ({H}∞ filtering) for removal of eye blinks, eye motions, amplitude drifts and recording biases simultaneously. We also characterize the volume conduction, by estimating the signal propagation levels across all EEG scalp recording areas due to ocular artifact generators. We find that the amplitude and spatial distribution of ocular artifacts vary greatly depending on the electrode location. Therefore, fixed filtering parameters for all recording areas would naturally hinder the true overall performance of an ANC scheme for artifact removal. We treat each electrode as a separate sub-system to be filtered, and without the loss of generality, they are assumed to be uncorrelated and uncoupled. Main results. Our results show over 95-99.9% correlation between the raw and processed signals at non-ocular artifact regions, and depending on the contamination profile, 40-70% correlation when ocular artifacts are dominant. We also compare our results with the offline independent component analysis and artifact subspace reconstruction methods, and show that some local quantities are handled better by our sample-adaptive real-time framework. Decoding performance is also compared with multi-day experimental data from 2 subjects

  1. Evaluation of a novel real-time fluorescent polymerase chain reaction assay for high-risk human papilloma virus DNA genotypes in cytological cervical screening.

    PubMed

    Cheng, Jiaoying; Bian, Meilu; Cong, Xiao; Sun, Aiping; Li, Min; Ma, Li; Chen, Ying; Liu, Jun

    2013-03-01

    It has been confirmed that detection of high-risk human papillomavirus (HR HPV) DNA is useful in cervical cancer (CC) screening. Recently, a new real-time fluorescent polymerase chain reaction (PCR) assay was developed to detect HR HPV. This assay can synchronize nucleic acid amplification and testing using specific primers for 13 types of HR HPV genomes, combined with specific TaqMan fluorescent marker probe techniques through the fluorescence automatic PCR instrument. Furthermore, it uses TaqGold™ DNA polymerase, which minimizes the amount of non-specific amplification and increases the sensitivity of the assay. The aim of this study was to evaluate the analytical and clinical performance of the real-time fluorescent PCR assay in CC screening, compared to the Qiagen Hybrid Capture(®) II High-Risk HPV DNA test(®) (HC II). In total, 1,252 cervical specimens were collected from women between 19 and 71 years of age. The specimens were examined with three different assays, real-time fluorescent PCR assay and HC II for HR HPV detection combined with liquid-based cytology. Women with cytological abnormalities or HR HPV-positive results underwent colposcopy and cervical biopsy. This study demonstrated good overall agreement between HC II and real-time fluorescent PCR assay (overall agreement, 92.25%; Cohen's κ=0.814). For the detection of high-grade cervical intraepithelial neoplasias (CIN) and CC, the sensitivity of HC II and real-time fluorescent PCR was 94.48 and 92.82%, respectively, and the negative predictive value was 98.85 and 98.54%, respectively. High HR HPV infection rate of the high-grade CIN and CC group was detected (P<0.05). In conclusion, real-time fluorescent PCR assay provides similar results compared to the HC II test for HR HPV detection and could be used in CC screening in clinic.

  2. Evaluation of a novel real-time fluorescent polymerase chain reaction assay for high-risk human papilloma virus DNA genotypes in cytological cervical screening

    PubMed Central

    CHENG, JIAOYING; BIAN, MEILU; CONG, XIAO; SUN, AIPING; LI, MIN; MA, LI; CHEN, YING; LIU, JUN

    2013-01-01

    It has been confirmed that detection of high-risk human papillomavirus (HR HPV) DNA is useful in cervical cancer (CC) screening. Recently, a new real-time fluorescent polymerase chain reaction (PCR) assay was developed to detect HR HPV. This assay can synchronize nucleic acid amplification and testing using specific primers for 13 types of HR HPV genomes, combined with specific TaqMan fluorescent marker probe techniques through the fluorescence automatic PCR instrument. Furthermore, it uses TaqGold™ DNA polymerase, which minimizes the amount of non-specific amplification and increases the sensitivity of the assay. The aim of this study was to evaluate the analytical and clinical performance of the real-time fluorescent PCR assay in CC screening, compared to the Qiagen Hybrid Capture® II High-Risk HPV DNA test® (HC II). In total, 1,252 cervical specimens were collected from women between 19 and 71 years of age. The specimens were examined with three different assays, real-time fluorescent PCR assay and HC II for HR HPV detection combined with liquid-based cytology. Women with cytological abnormalities or HR HPV-positive results underwent colposcopy and cervical biopsy. This study demonstrated good overall agreement between HC II and real-time fluorescent PCR assay (overall agreement, 92.25%; Cohen’s κ=0.814). For the detection of high-grade cervical intraepithelial neoplasias (CIN) and CC, the sensitivity of HC II and real-time fluorescent PCR was 94.48 and 92.82%, respectively, and the negative predictive value was 98.85 and 98.54%, respectively. High HR HPV infection rate of the high-grade CIN and CC group was detected (P<0.05). In conclusion, real-time fluorescent PCR assay provides similar results compared to the HC II test for HR HPV detection and could be used in CC screening in clinic. PMID:24648936

  3. Application of real-time digitization techniques in beam measurement for accelerators

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; Zhan, Lin-Song; Gao, Xing-Shun; Liu, Shu-Bin; An, Qi

    2016-04-01

    Beam measurement is very important for accelerators. In this paper, modern digital beam measurement techniques based on IQ (In-phase & Quadrature-phase) analysis are discussed. Based on this method and high-speed high-resolution analog-to-digital conversion, we have completed three beam measurement electronics systems designed for the China Spallation Neutron Source (CSNS), Shanghai Synchrotron Radiation Facility (SSRF), and Accelerator Driven Sub-critical system (ADS). Core techniques of hardware design and real-time system calibration are discussed, and performance test results of these three instruments are also presented. Supported by National Natural Science Foundation of China (11205153, 10875119), Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-N27), and the Fundamental Research Funds for the Central Universities (WK2030040029),and the CAS Center for Excellence in Particle Physics (CCEPP).

  4. Real-time detection of respiratory activity using an inertial measurement unit.

    PubMed

    Gollee, Henrik; Chen, Wei

    2007-01-01

    In this paper the use of an inertial measurement unit (IMU) to measure respiratory activity is presented. Movement of the abdomen was recorded by an IMU attached to a belt around the abdomen. The resulting signal was compared with reference measurements of the airflow at the mouth. The results of experimental evaluation show that the method can correctly detect the number of breaths together with the timing of the onsets of expiration and inspiration in real-time. They also indicate that the signal can be used to differentiate between different breathing situations. This novel method could therefore be suitable for use in automatic abdominal stimulation systems to support respiratory activity in tetraplegia where the stimulation is applied depending on the respirator activity of the subject.

  5. Adapting CALIPSO Climate Measurements for Near Real Time Analyses and Forecasting

    NASA Technical Reports Server (NTRS)

    Vaughan, Mark A.; Trepte, Charles R.; Winker, David M.; Avery, Melody A.; Campbell, James; Hoff, Ray; Young, Stuart; Getzewich, Brian J.; Tackett, Jason L.; Kar, Jayanta

    2011-01-01

    The Cloud-Aerosol Lidar and Infrared Pathfinder satellite Observations (CALIPSO) mission was originally conceived and designed as a climate measurements mission, with considerable latency between data acquisition and the release of the level 1 and level 2 data products. However, the unique nature of the CALIPSO lidar backscatter profiles quickly led to the qualitative use of CALIPSO?s near real time (i.e., ? expedited?) lidar data imagery in several different forecasting applications. To enable quantitative use of their near real time analyses, the CALIPSO project recently expanded their expedited data catalog to include all of the standard level 1 and level 2 lidar data products. Also included is a new cloud cleared level 1.5 profile product developed for use by operational forecast centers for verification of aerosol predictions. This paper describes the architecture and content of the CALIPSO expedited data products. The fidelity and accuracy of the expedited products are assessed via comparisons to the standard CALIPSO data products.

  6. Real-time Image Analysis of Living Cellular-Biology Measurements of Intelligent Chemistry

    SciTech Connect

    Solinsky, James C.; Budge, Scott E.; Majors, Paul D.; Rex, Bruce B.

    2003-08-01

    This paper reports on the Pacific Northwest National Laboratory (PNNL) DOE Initiative in Image Science and Technology (ISAT) research, which is developing algorithms and software tool sets for remote sensing and biological applications. In particular, the PNNL ISAT work is applying these research results to the automated analysis of real-time cellular biology imagery to assist the biologist in determining the correct data collection region for the current state of a conglomerate of living cells in three-dimensional motion. The real-time computation of the typical 120 MB/sec multi-spectral data sets is executed in a Field Programmable Gate Array (FPGA) technology, which has very high processing rates due to large-scale parallelism. The outcome of this artificial vision work will allow the biologist to work with imagery as a creditable set of dye-tagged chemistry measurements in formats for individual cell tracking through regional feature extraction, and animation visualization through individual object isolation/characterization of the microscopy imagery.

  7. Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR.

    PubMed

    Balzan, Riccardo; Fernandes, Laetitia; Comment, Arnaud; Pidial, Laetitia; Tavitian, Bertrand; Vasos, Paul R

    2016-02-23

    The main limitation of NMR-based investigations is low sensitivity. This prompts for long acquisition times, thus preventing real-time NMR measurements of metabolic transformations. Hyperpolarization via dissolution DNP circumvents part of the sensitivity issues thanks to the large out-of-equilibrium nuclear magnetization stemming from the electron-to-nucleus spin polarization transfer. The high NMR signal obtained can be used to monitor chemical reactions in real time. The downside of hyperpolarized NMR resides in the limited time window available for signal acquisition, which is usually on the order of the nuclear spin longitudinal relaxation time constant, T1, or, in favorable cases, on the order of the relaxation time constant associated with the singlet-state of coupled nuclei, TLLS. Cellular uptake of endogenous molecules and metabolic rates can provide essential information on tumor development and drug response. Numerous previous hyperpolarized NMR studies have demonstrated the relevancy of pyruvate as a metabolic substrate for monitoring enzymatic activity in vivo. This work provides a detailed description of the experimental setup and methods required for the study of enzymatic reactions, in particular the pyruvate-to-lactate conversion rate in presence of lactate dehydrogenase (LDH), by hyperpolarized NMR.

  8. Real-time dual-loop electric current measurement for label-free nanofluidic preconcentration chip.

    PubMed

    Chung, Pei-Shan; Fan, Yu-Jui; Sheen, Horn-Jiunn; Tian, Wei-Cheng

    2015-01-07

    An electrokinetic trapping (EKT)-based nanofluidic preconcentration device with the capability of label-free monitoring trapped biomolecules through real-time dual-loop electric current measurement was demonstrated. Universal current-voltage (I-V) curves of EKT-based preconcentration devices, consisting of two microchannels connected by ion-selective channels, are presented for functional validation and optimal operation; universal onset current curves indicating the appearance of the EKT mechanism serve as a confirmation of the concentrating action. The EKT mechanism and the dissimilarity in the current curves related to the volume flow rate (Q), diffusion coefficient (D), and diffusion layer (DL) thickness were explained by a control volume model with a five-stage preconcentration process. Different behaviors of the trapped molecular plug were categorized based on four modes associated with different degrees of electroosmotic instability (EOI). A label-free approach to preconcentrating (bio)molecules and monitoring the multibehavior molecular plug was demonstrated through real-time electric current monitoring, rather than through the use of microscope images.

  9. Real-time simultaneous temperature and strain measurements at cryogenic temperatures in an optical fiber

    NASA Astrophysics Data System (ADS)

    Mahar, Scott; Geng, Jihong; Schultz, Joel; Minervini, Joseph; Jiang, Shibin; Titus, Peter; Takayasu, Makoto; Gung, Chen-yu; Tian, Wenyan; Chavez-Pirson, Arturo

    2008-08-01

    A novel fiber optic sensor has been developed to be used in superconducting magnets for fusion reactors and other large cable-in-conduit superconductor (CICC) magnet applications. These large superconducting magnets need a diagnostic that can measure the temperature and strain throughout the magnet in real-time, which was not possible until now. Simultaneous temperature and strain measurements at cryogenic temperatures have been demonstrated, using spontaneous Brillouin scattering in an optical fiber. Using an extremely narrow (100 Hz) linewidth Brillouin laser with very low noise as a frequency shifted local oscillator, the frequency shift of spontaneous Brillouin scattered light was measured using heterodyne detection. A pulsed laser was used to probe the fiber using Optical Time Domain Reflectometry (OTDR) to determine spatial resolution. The spontaneous Brillouin frequency shift and linewidth as a function of temperature agree with previous literature on stimulated Brillouin scattering data from room temperature down to 4 K. For the first time, the spontaneous Brillouin frequency shift, linewidth, and intensity as a function of strain have been measured down to 4 K. Analyzing the frequency spectrum of the scattered light after an FFT gives the Brillouin frequency shift, linewidth, and intensity of the scattered light. 65,000 pulses, with 53 ns pulse widths, were averaged in under one second, providing a 5 meter spatial resolution along a fiber that was about 100 m long. Measuring these three parameters allow the simultaneous determination of temperature and strain in real-time throughout a fiber with a spatial resolution on the order of several meters.

  10. Real-Time Protein and Cell Binding Measurements on Hydroxyapatite Coatings

    PubMed Central

    Vilardell, A. M.; Cinca, N.; Jokinen, A.; Garcia-Giralt, N.; Dosta, S.; Cano, I. G.; Guilemany, J. M.

    2016-01-01

    Although a lot of in vitro and in vivo assays have been performed during the last few decades years for hydroxyapatite bioactive coatings, there is a lack of exploitation of real-time in vitro interaction measurements. In the present work, real-time interactions for a plasma sprayed hydroxyapatite coating were measured by a Multi-Parametric Surface Plasmon Resonance (MP-SPR), and the results were compared with standard traditional cell viability in vitro assays. MP-SPR is proven to be suitable not only for measurement of molecule–molecule interactions but also molecule–material interaction measurements and cell interaction. Although SPR is extensively utilized in interaction studies, recent research of protein or cell adsorption on hydroxyapatite coatings for prostheses applications was not found. The as-sprayed hydroxyapatite coating resulted in 62.4% of crystalline phase and an average thickness of 24 ± 6 μm. The MP-SPR was used to measure lysozyme protein and human mesenchymal stem cells interaction to the hydroxyapatite coating. A comparison between the standard gold sensor and Hydroxyapatite (HA)-plasma coated sensor denoted a clearly favourable cell attachment on HA coated sensor as a significantly higher signal of cell binding was detected. Moreover, traditional cell viability and proliferation tests showed increased activity with culture time indicating that cells were proliferating on HA coating. Cells show homogeneous distribution and proliferation along the HA surface between one and seven days with no significant mortality. Cells were flattened and spread on rough surfaces from the first day, with increasing cytoplasmatic extensions during the culture time. PMID:27618911

  11. High-resolution micromechanical measurement in real time of forces exerted by living cells.

    PubMed

    Swierczewski, Robert; Hedley, John; Redfern, Chris P F

    2016-05-03

    The aim of this study was to compare uniaxial traction forces exerted by different cell types using a novel sensor design and to test the dependence of measured forces on cytoskeletal integrity. The sensor design detects forces generated between 2 contact points by cells spanning a gap. The magnitude of these forces varied according to cell type and were dependent on cytoskeletal integrity. The response time for drug-induced cytoskeletal disruption also varied between cell types: dermal fibroblasts exerted the greatest forces and had the slowest drug response times; EBV-transformed epithelial cells also had slow cytoskeletal depolymerisation times but exerted the lowest forces overall. Conversely, lung epithelial tumor cells exerted low forces but had the fastest depolymerisation drug response. These results provide proof of principle for a new design of force-measurement sensor based on optical interferometry, an approach that can be used to study cytoskeletal dynamics in real time.

  12. A Real-Time Optical Tracking and Measurement Processing System for Flying Targets

    PubMed Central

    Guo, Pengyu; Ding, Shaowen; Zhang, Hongliang; Zhang, Xiaohu

    2014-01-01

    Optical tracking and measurement for flying targets is unlike the close range photography under a controllable observation environment, which brings extreme conditions like diverse target changes as a result of high maneuver ability and long cruising range. This paper first designed and realized a distributed image interpretation and measurement processing system to achieve resource centralized management, multisite simultaneous interpretation and adaptive estimation algorithm selection; then proposed a real-time interpretation method which contains automatic foreground detection, online target tracking, multiple features location, and human guidance. An experiment is carried out at performance and efficiency evaluation of the method by semisynthetic video. The system can be used in the field of aerospace tests like target analysis including dynamic parameter, transient states, and optical physics characteristics, with security control. PMID:24987748

  13. Traffic dynamics: Method for estimating freeway travel times in real time from flow measurements

    SciTech Connect

    Nam, D.H.; Drew, D.R.

    1996-05-01

    This paper presents a method for estimating freeway travel times in real time directly from flow measurements, which is desirable for present and future Intelligent Vehicle-Highway Systems (IVHS) applications. An inductive modeling approach adapted here is based on stochastic queuing theory and the principle of conservation of vehicles. The analytical expression for link travel times satisfies traffic dynamics where the new form of the conservation of vehicles has been derived under generalized traffic conditions. A computer program has been developed to implement the algorithm. Analysis results show that the estimates have good agreement with empirical data measured at 30-s intervals. This methodology has potential applicable to automatic traffic control and automatic incident detection.

  14. (abstract) Using GPS Measurements to Identify Global Ionospheric Storms in Near Real-Time

    NASA Technical Reports Server (NTRS)

    Ho, C. M.; Mannucci, A. J.; Lindqwister, U. J.; Rao, A. M.; Pi, X.; Wilson, B. D.; Yuan, D. N.; Reyes, M.

    1996-01-01

    The solar wind interacts with the Earth's magnetosphere, eventually dissipating energy into the ionosphere and atmosphere. As a terminator, the ionosphere responds to magnetic storms, which is very important in understanding the energy coupling process between the Sun and the Earth and in forecasting space weather changes.The worldwide GPS network, for the first time, makes near real-time global ionospheric TEC measurements a possibility. Based on these measurements, global ionospheric TEC maps are generated with time resolution of from 5 minutes to hours. Using these maps, we can analyze the global evolution of ionospheric storms on temporal and spatial scales, which have been dificult to study before. We find that for certain types of storms (such as TID-driven), it is possible to identify them near onset and issue warning signals during the early stages. Main attention has been paid on northern hemispheric winter storms. Their common features and physical mechanisms are being investigated.

  15. Design of real-time measurement for optical fiber positioning based on FPGA

    NASA Astrophysics Data System (ADS)

    Han, Huajie; Gu, Yonggang; Liu, Guocheng; Zhai, Chao

    2016-07-01

    In order to track the stellar objects in fiber spectroscopic telescopes, measuring the fiber positions is necessary, which is currently unsolved due to the large number of data. In this paper, we propose a novel measure method based on the Field Programmable Gate Arrays (FPGA). Firstly, the fiber spots are obtained from the complicated original images by preprocessing including the median filtering technique to remove the image noise and the correlation operation technique to enhance the fiber spot characteristic. Then, a novel fast connected component labeling technique is employed to acquire the accurate fiber positions. The design of the image processing system is realized by a five-stage pipeline technique based on the FPGA, thus the image processing speed is greatly improved and meanwhile the real-time calculation of the fiber positions is fulfilled.

  16. (abstract) Using GPS Measurements to Identify Global Ionospheric Storms in Near Real-Time

    NASA Technical Reports Server (NTRS)

    Ho, C. M.; Mannucci, A. J.; Lindqwister, U. J.; Rao, A. M.; Pi, X.; Wilson, B. D.; Yuan, D. N.; Reyes, M.

    1996-01-01

    The solar wind interacts with the Earth's magnetosphere, eventually dissipating energy into the ionosphere and atmosphere. As a terminator, the ionosphere responds to magnetic storms, which is very important in understanding the energy coupling process between the Sun and the Earth and in forecasting space weather changes.The worldwide GPS network, for the first time, makes near real-time global ionospheric TEC measurements a possibility. Based on these measurements, global ionospheric TEC maps are generated with time resolution of from 5 minutes to hours. Using these maps, we can analyze the global evolution of ionospheric storms on temporal and spatial scales, which have been dificult to study before. We find that for certain types of storms (such as TID-driven), it is possible to identify them near onset and issue warning signals during the early stages. Main attention has been paid on northern hemispheric winter storms. Their common features and physical mechanisms are being investigated.

  17. Comparative Analysis of Fluorescence In Situ Hybridization and Real Time Polymerase Chain Reaction in Diagnosis of Chronic Myeloid Leukemia.

    PubMed

    Ali, Javaid; Khan, Saleem Ahmed; Rauf, Shan -E-; Ayyub, Muhammad; Ali, Nadir; Afridi, Nabeel Khan

    2017-01-01

    To compare the sensitivity and specificity of fluorescence in situ hybridization (FISH) with real time polymerase chain reaction (RT-PCR) in the diagnosis of Chronic Myeloid Leukemia (CML). A cross-sectional, analytical study. Haematology Department, Armed Forces Institute of Pathology, Rawalpindi, from January 2012 to February 2014. A total number of 87 patients of CML were studied. The diagnosis was made on the basis of clinical history, peripheral blood and bone marrow aspiration. These patients were tested for the presence of BCR-ABL1 fusion gene by RT-PCR and FISH. About 5 ml of venous blood was collected, half was taken in heparin for FISH and half in ethylenediamine tetra-acetic acid (EDTA) for CBC and PCR. For FISH, cells were cultured for 24 hours in RPMI 1640 medium and evaluated using BX51 fluorescence microscope for dual fusion signal of yellow colour. Samples having 20 or more interphases positive for dual fusion signals were taken as positive. For PCR, RNA extraction was done by Tri-Reagent LS (MRC, USA) and cDNA was synthesized using reverse transcriptase and gene specific primer. RT-PCR was done on ABI-7500. The positive samples were identified when fluorescence exceeded threshold limit. Results of RT-PCR and FISH were compared. Out of the 87 patients, 85 (97.7%) were PCR positive and 2 (2.3%) were PCR negative, whereas in FISH 83 (95.4%) were positive and 4 (4.5%) were negative. Sensitivity and specificity of FISH was 97.6% and 100%, respectively. FISH is a reliable supplementary method to PCR for detection of BCR-ABL1 fusion gene in the diagnosis of CML.

  18. Self-referencing luminescent optrodes for non-invasive, real time measurement of extracellular flux

    NASA Astrophysics Data System (ADS)

    McLamore, Eric S.; Porterfield, D. Marshall; Borgens, R. B.; Banks, M. K.

    2011-05-01

    Autonomous technologies are needed which are capable of sensing real time changes in biophysical transport across cell membranes/organelles. These technologies must not only be highly sensitive/selective, but must also be minimally invasive/intrusive, causing no significant physical/chemical effects on cell behavior. Challenges with mainstream technologies (e.g., assays, fluorescent dyes, microsensors) include signal noise/drift, low temporal resolution, requirement of large sample sizes, cytoxicity, organelle sequestration, and intracellular buffering. Recent advancements in fiber optics have greatly enhanced the performance of microsensors (e.g., increased sensitivity/selectivity, response time), but used in concentration mode near cells/tissues these sensors suffer from poor signal to noise ratio. Work over the last few decades has advanced microsensor utility through sensing modalities that extend and enhance the data recorded by sensors. This technique, known as self-referencing, converts static micro/nanosensors with otherwise low signal-to-noise ratios into dynamic flux sensors capable of filtering out signals not associated with active transport by acquisition and amplification of differential signals. Here, we demonstrate the use of a self-referencing referencing frequency domain fiber optic microsensor containing a quenched dye (platinum tetrakis-pentafluorophenyl porphyrin) for quantifying cell/tissue flux in biomedical, agricultural, and environmental applications.

  19. Monitoring of ovarian cancer cell invasion in real time with frequency-dependent impedance measurement.

    PubMed

    Lo, Chun-Min; Lo, Jun-Chih; Sato, Priscila Y; Yeung, Tsz-Lun; Mok, Samuel C; Yip, Kay-Pong

    2016-12-01

    The conventional approach to assessing cancer invasion is primarily for end-point analysis, which does not provide temporal information on the invasion process or any information on the interactions between invading cells and the underlying adherent cells. To alleviate these limitations, the present study exploited electric cell-substrate impedance sensing (ECIS) to monitor the invasion of ovarian cancer cells (SKOV-3) through an adherent monolayer of human umbilical vein endothelial cells (HUVECs). Impedance was measured at 4 kHz of AC voltage or was measured as a function of AC frequency (25 Hz to 60 kHz). By measuring impedance at 4-kHz AC, we found that the invasion of SKOV-3 cells through the HUVEC monolayer was manifested as a rapid decrease in transendothelial electrical resistance in real time. The invasion was augmented in the presence of hepatocyte growth factor (HGF). The enhancing effect of HGF was attenuated by c-Met inhibitor (SU11274). By measuring the frequency-dependent impedance of SKOV-3 cells over time, we found that HGF-enhanced SKOV-3 cell invasion was accomplished with reduced junctional resistance (Rb), increased average cell-substrate separation (h), and increased micromotion. SU11274 attenuated the effects of HGF on Rb, h, and micromotion in the SKOV-3 monolayer. SU11274 also increased the barrier function of the HUVEC monolayer by increasing Rb and decreasing h In conclusion, this study demonstrated an improved method for monitoring and studying the interactions between cancer cells and the underlying adherent cells during invasion in real time. Alterations in cellular biophysical properties (Rb, h) associated with cancer transendothelial invasion were detected. Copyright © 2016 the American Physiological Society.

  20. Measuring Sea-Ice Motion in the Arctic with Real Time Photogrammetry

    NASA Astrophysics Data System (ADS)

    Brozena, J. M.; Hagen, R. A.; Peters, M. F.; Liang, R.; Ball, D.

    2014-12-01

    The U.S. Naval Research Laboratory, in coordination with other groups, has been collecting sea-ice data in the Arctic off the north coast of Alaska with an airborne system employing a radar altimeter, LiDAR and a photogrammetric camera in an effort to obtain wide swaths of measurements coincident with Cryosat-2 footprints. Because the satellite tracks traverse areas of moving pack ice, precise real-time estimates of the ice motion are needed to fly a survey grid that will yield complete data coverage. This requirement led us to develop a method to find the ice motion from the aircraft during the survey. With the advent of real-time orthographic photogrammetric systems, we developed a system that measures the sea ice motion in-flight, and also permits post-process modeling of sea ice velocities to correct the positioning of radar and LiDAR data. For the 2013 and 2014 field seasons, we used this Real Time Ice Motion Estimation (RTIME) system to determine ice motion using Applanix's Inflight Ortho software with an Applanix DSS439 system. Operationally, a series of photos were taken in the survey area. The aircraft then turned around and took more photos along the same line several minutes later. Orthophotos were generated within minutes of collection and evaluated by custom software to find photo footprints and potential overlap. Overlapping photos were passed to the correlation software, which selects a series of "chips" in the first photo and looks for the best matches in the second photo. The correlation results are then passed to a density-based clustering algorithm to determine the offset of the photo pair. To investigate any systematic errors in the photogrammetry, we flew several flight lines over a fixed point on various headings, over an area of non-moving ice in 2013. The orthophotos were run through the correlation software to find any residual offsets, and run through additional software to measure chip positions and offsets relative to the aircraft

  1. Real-time HF Radio Absorption Maps Incorporating Riometer and Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Rogers, Neil; Honary, Farideh; Warrington, Mike; Stocker, Alan; Danskin, Donald

    2016-04-01

    A real-time model of HF radio propagation conditions is being developed as a service for aircraft communications at high latitudes. An essential component of this is a real-time map of the absorption of HF (3-30 MHz) radio signals in the D-region ionosphere. Empirical, climatological Polar Cap Absorption (PCA) models in common usage cannot account for day-to-day variations in ionospheric composition and are inaccurate during the large changes in recombination rate at twilight. However, parameters of such models may be optimised using an age-weighted regression to absorption measurements from riometers in Canada and Scandinavia. Such parameters include the day- and night-time sensitivity to proton flux as measured on a geostationary satellite (GOES). Modelling the twilight transition as a linear or Gauss error function over a range of solar-zenith angles (χl < χ < χu) is found to provide greater accuracy than 'Earth shadow' methods (as applied in the Sodankylä Ionospheric Chemistry (SIC) model, for example) due to a more gradual ionospheric response for χ < 90° . The fitted χl parameter is found to be most variable, with smaller values (as low as 60°) post-sunrise compared with pre-sunset. Correlation coefficients of model parameters between riometers are presented and these provide a means of appropriately weighting individual riometer contributions in an assimilative PCA model. At times outside of PCA events, the probability of absorption in the auroral zones is related to the energetic electron flux inside the precipitation loss cone, as measured on the polar-orbiting POES satellites. This varies with magnetic local time, magnetic latitude and geomagnetic activity, and its relation to the real-time solar wind - magnetospheric coupling function [Newell et al., 2007] will be presented. Reference: Newell, P. T., T. Sotirelis, K. Liou, C.-I. Meng, and F. J. Rich (2007), A nearly universal solar wind-magnetosphere coupling function inferred from 10

  2. Self-calibrating, real-time M-square measurement system

    NASA Astrophysics Data System (ADS)

    Scaggs, Michael; Haas, Gil

    2017-02-01

    M-square measurements since the inception of the ISO 11146-1 measurement standard of 1996 has been one that has been difficult even for a seasoned veteran of such measurements. Variations of more than 10% are not uncommon for the same measurement tool on the same laser being measured. Much of the variation comes from alignment, the motion involved (time averaged based), complex attenuation techniques which often include variable neutral density filters and the type of sensors employed. Moreover, setup times for the instrument can take hours and the measurements themselves many minutes. Measurement of a laser or a laser systems' M-square should be as simple as measuring the power of the laser. In that one aligns the laser to the device; put the device in self calibration mode; make a measurement. In 2012 the authors developed a passive optical design that provided real-time M-square measurement of a laser or laser system but nevertheless still required calibration of the key optics within the system: a Fabry-Perot etalon pair and their spacing in order to obtain an accurate M-square result. Using existing data from the sensor along with a simple ray tracing technique, the etalon spacing can be determined with high accuracy through the deconvolution of the data from the sensor; thereby eliminating a separate time consuming calibration. The key calibration information can now be obtained in a fraction of a second without any effort on the part of the user.

  3. Towards real time spatially resolved data on sediment transport: 1) tracing the motion of the fluorescent soil particles under rainfall

    NASA Astrophysics Data System (ADS)

    Quinton, John; Hardy, Rob; Pates, Jackie; James, Mike

    2017-04-01

    Understanding where sediment originates from and where it travels to, in what quantities and at which rate is at the heart of many questions surrounding sediment transport, including the connectivity problem. Progress towards unravelling these questions and deepening our understanding has come from a wide range of approaches, including laboratory and field experiments conducted at a variety of scales. In seeking to understand the connectivity of sources and sinks of sediment scientists have spent considerable energy in developing tracing technologies. These have included numerous studies that have relied on the chemical properties of the soil and sediment to establish source-sink connectivity, and the use of 137Ceasium, from radioactive fall-out, to map sediment redistribution. More recently there has been an upsurge in interest in the use of artificially applied soil tracers, including rare earth element oxides and magnetic minerals. However all these tracing methods have a significant drawback: they rely on the collection of samples to assess their concentration. This means that their spatial distribution cannot easily be established in situ and that the environment that is being studied is damaged by the sampling process; nor can data be collected in real time which allows a dynamic understanding of erosion and transport processes to be developed. In this paper we present a methodology for use with a commercially available fluorescent tracer. The tracer is produced in a range of sizes and fluorescent signatures and can be applied to the soil surface. Here we report on an application that combines novel fluorescent videography techniques with custom image processing to trace the motion of the fluorescent soil particles under rainfall. Here we demonstrate the tracking of multiple sub-millimetre particles simultaneously, establishing their position 50 times a second with submillimetre precision. From this we are able to visualise and quantify parameters such as

  4. Applications of Kalman filtering to real-time trace gas concentration measurements

    NASA Technical Reports Server (NTRS)

    Leleux, D. P.; Claps, R.; Chen, W.; Tittel, F. K.; Harman, T. L.

    2002-01-01

    A Kalman filtering technique is applied to the simultaneous detection of NH3 and CO2 with a diode-laser-based sensor operating at 1.53 micrometers. This technique is developed for improving the sensitivity and precision of trace gas concentration levels based on direct overtone laser absorption spectroscopy in the presence of various sensor noise sources. Filter performance is demonstrated to be adaptive to real-time noise and data statistics. Additionally, filter operation is successfully performed with dynamic ranges differing by three orders of magnitude. Details of Kalman filter theory applied to the acquired spectroscopic data are discussed. The effectiveness of this technique is evaluated by performing NH3 and CO2 concentration measurements and utilizing it to monitor varying ammonia and carbon dioxide levels in a bioreactor for water reprocessing, located at the NASA-Johnson Space Center. Results indicate a sensitivity enhancement of six times, in terms of improved minimum detectable absorption by the gas sensor.

  5. Real-Time Unsteady Loads Measurements Using Hot-Film Sensors

    NASA Technical Reports Server (NTRS)

    Mangalam, Arun S.; Moes, Timothy R.

    2004-01-01

    Several flight-critical aerodynamic problems such as buffet, flutter, stall, and wing rock are strongly affected or caused by abrupt changes in unsteady aerodynamic loads and moments. Advanced sensing and flow diagnostic techniques have made possible simultaneous identification and tracking, in realtime, of the critical surface, viscosity-related aerodynamic phenomena under both steady and unsteady flight conditions. The wind tunnel study reported here correlates surface hot-film measurements of leading edge stagnation point and separation point, with unsteady aerodynamic loads on a NACA 0015 airfoil. Lift predicted from the correlation model matches lift obtained from pressure sensors for an airfoil undergoing harmonic pitchup and pitchdown motions. An analytical model was developed that demonstrates expected stall trends for pitchup and pitchdown motions. This report demonstrates an ability to obtain unsteady aerodynamic loads in real time, which could lead to advances in air vehicle safety, performance, ride-quality, control, and health management.

  6. FPGA-based real-time phase measuring profilometry algorithm design and implementation

    NASA Astrophysics Data System (ADS)

    Zhan, Guomin; Tang, Hongwei; Zhong, Kai; Li, Zhongwei; Shi, Yusheng

    2016-11-01

    Phase measuring profilometry (PMP) has been widely used in many fields, like Computer Aided Verification (CAV), Flexible Manufacturing System (FMS) et al. High frame-rate (HFR) real-time vision-based feedback control will be a common demands in near future. However, the instruction time delay in the computer caused by numerous repetitive operations greatly limit the efficiency of data processing. FPGA has the advantages of pipeline architecture and parallel execution, and it fit for handling PMP algorithm. In this paper, we design a fully pipelined hardware architecture for PMP. The functions of hardware architecture includes rectification, phase calculation, phase shifting, and stereo matching. The experiment verified the performance of this method, and the factors that may influence the computation accuracy was analyzed.

  7. Sinusoidal-wavelength-scanning interferometer with double feedback control for real-time distance measurement.

    PubMed

    Sasaki, Osami; Akiyama, Kazuhiro; Suzuki, Takamasa

    2002-07-01

    In addition to a conventional phase a the interference signal of a sinusoidal-wavelength-scanning interferometer has a phase-modulation amplitude Zb that is proportional to the optical path difference L and amplitude b of the wavelength scan. L and b are controlled by a double feedback system so that the phase alpha and the amplitude Zb are kept at 3pi/2 and pi, respectively. The voltage applied to a device that displaces a reference mirror to change the optical path difference becomes a ruler with scales smaller than a wavelength. Voltage applied to a device that determines the amplitude of the wavelength scan becomes a ruler marking every wavelength. These two rulers enable one to measure an absolute distance longer than a wavelength in real time.

  8. Real-time measurements of spontaneous breathers and rogue wave events in optical fibre modulation instability.

    PubMed

    Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M

    2016-12-19

    Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose-Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics.

  9. Prediction of solar energetic particle event histories using real-time particle and solar wind measurements

    NASA Technical Reports Server (NTRS)

    Roelof, E. C.; Gold, R. E.

    1978-01-01

    The comparatively well-ordered magnetic structure in the solar corona during the decline of Solar Cycle 20 revealed a characteristic dependence of solar energetic particle injection upon heliographic longitude. When analyzed using solar wind mapping of the large scale interplanetary magnetic field line connection from the corona to the Earth, particle fluxes display an approximately exponential dependence on heliographic longitude. Since variations in the solar wind velocity (and hence the coronal connection longitude) can severely distort the simple coronal injection profile, the use of real-time solar wind velocity measurements can be of great aid in predicting the decay of solar particle events. Although such exponential injection profiles are commonplace during 1973-1975, they have also been identified earlier in Solar Cycle 20, and hence this structure may be present during the rise and maximum of the cycle, but somewhat obscured by greater temporal variations in particle injection.

  10. Real-time measurements of spontaneous breathers and rogue wave events in optical fibre modulation instability

    NASA Astrophysics Data System (ADS)

    Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M.

    2016-12-01

    Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose-Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics.

  11. Real-time measurements of D/log-E curves in holographic emulsions: experimental results

    NASA Astrophysics Data System (ADS)

    Fimia, Antonio; Blaya-Escarre, Salvador; Carretero-Lopez, Luis; Madrigal, Roque F.; Mallavia, Ricardo M.

    1999-03-01

    The response curve D-Log E is the most important method to characterize photographic emulsions. In this work we present the experimental study using a real time technique that can be applied to the improvement of the holographic properties of emulsions. We have exposured an Agfa Gevaert 8E56HD emulsion with an Argon laser tuned at 514 nm. After it, we measured the transmittance curve when the emulsion was into the developer bath function of time at 20 degrees Celsius. This method gives us the possibility of study the dynamics of different developers as a function of the storage energy. It also provides a way to optimize the composition of developers function of the chemical composition, temperature and other secondary factors as superaditivity and non-linear processes.

  12. Real-time measurements of spontaneous breathers and rogue wave events in optical fibre modulation instability

    PubMed Central

    Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M.

    2016-01-01

    Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose–Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics. PMID:27991513

  13. Damage dosimetry and embrittlement monitoring of nuclear pressure vessels in real time by magnetic properties measurement

    SciTech Connect

    Stubbins, J.F.; Ougouag, A.M.; Williams, J.G.

    1992-07-01

    The objective of this project is to develop a technique for real-time monitoring of neutron dose and of the onset and progression of embrittlement in operating nuclear pressure vessels. The technique relies on the measurement of magnetic properties of steel and other magnetic materials which are extremely sensitive to radiation-induced properties changes. The approach being developed here is innovative and unique. It promises to be readily applicable to all existing and planned reactor structures. The significance of this program is that it addresses a major concern in the operation of existing nuclear pressure vessels. The development of microscopic defect clusters during irradiation in the nuclear pressure vessel beltline region leads to an increase in material yield strength and a concomitant decrease in ductility, or ability to absorb energy in fracture (i.e. fracture toughness). This decrease in fracture toughness is alarming since it may impair the ability of the pressure vessel to resist fracture during unusual loading situations.

  14. Applications of Kalman filtering to real-time trace gas concentration measurements

    NASA Technical Reports Server (NTRS)

    Leleux, D. P.; Claps, R.; Chen, W.; Tittel, F. K.; Harman, T. L.

    2002-01-01

    A Kalman filtering technique is applied to the simultaneous detection of NH3 and CO2 with a diode-laser-based sensor operating at 1.53 micrometers. This technique is developed for improving the sensitivity and precision of trace gas concentration levels based on direct overtone laser absorption spectroscopy in the presence of various sensor noise sources. Filter performance is demonstrated to be adaptive to real-time noise and data statistics. Additionally, filter operation is successfully performed with dynamic ranges differing by three orders of magnitude. Details of Kalman filter theory applied to the acquired spectroscopic data are discussed. The effectiveness of this technique is evaluated by performing NH3 and CO2 concentration measurements and utilizing it to monitor varying ammonia and carbon dioxide levels in a bioreactor for water reprocessing, located at the NASA-Johnson Space Center. Results indicate a sensitivity enhancement of six times, in terms of improved minimum detectable absorption by the gas sensor.

  15. Real time chromametry measurement for food quality detection using mobile device

    NASA Astrophysics Data System (ADS)

    Witjaksono, Gunawan; Mohamad Hussin, Nur Haziqah Farah Binti; Abdelkreem Saeed Rabih, Almur; Alfa, Sagir

    2017-09-01

    Freshness of the food is the main factor in determining the quality and safety of the consumed food and hence consumers satisfaction. Current technologies for food quality determination depend on colour changing labels to indicate the freshness level, which is subjective to human eyes. The goal of this paper is to design and develop chromatic algorithm based on RGB colour reading and correlation with pH values for real time determination of freshness level of shrimp. The results show that the developed algorithm is able to measure, analyse and display the freshness level of food directly on the screen of a mobile app technology. The mobile app is developed on Android platform and is tested in the shrimp freshness range by stating whether it is “fresh, good or spoiled”.

  16. Investigation of telomere lengths measurement by quantitative real-time PCR to predict age.

    PubMed

    Hewakapuge, Sudinna; van Oorschot, Roland A H; Lewandowski, Paul; Baindur-Hudson, Swati

    2008-09-01

    Currently DNA profiling methods only compare a suspect's DNA with DNA left at the crime scene. When there is no suspect, it would be useful for the police to be able to predict what the person of interest looks like by analysing the DNA left behind in a crime scene. Determination of the age of the suspect is an important factor in creating an identikit. Human somatic cells gradually lose telomeric repeats with age. This study investigated if one could use a correlation between telomere length and age, to predict the age of an individual from their DNA. Telomere length, in buccal cells, of 167 individuals aged between 1 and 96 years old was measured using real-time quantitative PCR. Telomere length decreased with age (r=-0.185, P<0.05) and the age of an individual could be roughly determined by the following formula: (age=relative telomere length -1.5/-0.005). The regression (R(2)) value between telomere length and age was approximately 0.04, which is too low to be use for forensics. The causes for the presence of large variation in telomere lengths in the population were further investigated. The age prediction accuracies were low even after dividing samples into non-related Caucasians, males and females (5%, 9% and 1%, respectively). Mean telomere lengths of eight age groups representing each decade of life showed non-linear decrease in telomere length with age. There were variations in telomere lengths even among similarly aged individuals aged 26 years old (n=10) and age 54 years old (n=9). Therefore, telomere length measurement by real-time quantitative PCR cannot be used to predict age of a person, due to the presence of large inter-individual variations in telomere lengths.

  17. Real-time measurements of endogenous CO production from vascular cells using an ultrasensitive laser sensor

    NASA Technical Reports Server (NTRS)

    Morimoto, Y.; Durante, W.; Lancaster, D. G.; Klattenhoff, J.; Tittel, F. K.

    2001-01-01

    Carbon monoxide (CO) has been implicated as a biological messenger molecule analogous to nitric oxide. A compact gas sensor based on a midinfrared laser absorption spectroscopy was developed for direct and real-time measurement of trace levels (in approximate pmol) of CO release by vascular cells. The midinfrared light is generated by difference frequency mixing of two nearinfrared lasers in a nonlinear optical crystal. A strong infrared absorption line of CO (4.61 microm) is chosen for convenient CO detection without interference from other gas species. The generation of CO from cultured vascular smooth muscle cells was detected every 20 s without any chemical modification to the CO. The sensitivity of the sensor reached 6.9 pmol CO. CO synthesis was measured from untreated control cells (0.25 nmol per 10(7) cells/h), sodium nitroprusside-treated cells (0.29 nmol per 10(7) cells/h), and hemin-treated cells (0.49 nmol per 10(7) cells/h). The sensor also detected decreases in CO production after the addition of the heme oxygenase (HO) inhibitor tin protoporphyrin-IX (from 0.49 to 0.02 nmol per 10(7) cells/h) and increases after the administration of the HO substrate hemin (from 0.27 to 0.64 nmol per 10(7) cells/h). These results demonstrate that midinfrared laser absorption spectroscopy is a useful technique for the noninvasive and real-time detection of trace levels of CO from biological tissues.

  18. Real-time measurements of endogenous CO production from vascular cells using an ultrasensitive laser sensor

    NASA Technical Reports Server (NTRS)

    Morimoto, Y.; Durante, W.; Lancaster, D. G.; Klattenhoff, J.; Tittel, F. K.

    2001-01-01

    Carbon monoxide (CO) has been implicated as a biological messenger molecule analogous to nitric oxide. A compact gas sensor based on a midinfrared laser absorption spectroscopy was developed for direct and real-time measurement of trace levels (in approximate pmol) of CO release by vascular cells. The midinfrared light is generated by difference frequency mixing of two nearinfrared lasers in a nonlinear optical crystal. A strong infrared absorption line of CO (4.61 microm) is chosen for convenient CO detection without interference from other gas species. The generation of CO from cultured vascular smooth muscle cells was detected every 20 s without any chemical modification to the CO. The sensitivity of the sensor reached 6.9 pmol CO. CO synthesis was measured from untreated control cells (0.25 nmol per 10(7) cells/h), sodium nitroprusside-treated cells (0.29 nmol per 10(7) cells/h), and hemin-treated cells (0.49 nmol per 10(7) cells/h). The sensor also detected decreases in CO production after the addition of the heme oxygenase (HO) inhibitor tin protoporphyrin-IX (from 0.49 to 0.02 nmol per 10(7) cells/h) and increases after the administration of the HO substrate hemin (from 0.27 to 0.64 nmol per 10(7) cells/h). These results demonstrate that midinfrared laser absorption spectroscopy is a useful technique for the noninvasive and real-time detection of trace levels of CO from biological tissues.

  19. Real-time assessment of cardiac perfusion, coronary angiography, and acute intravascular thrombi using dual-channel near-infrared fluorescence imaging.

    PubMed

    Tanaka, Eiichi; Chen, Frederick Y; Flaumenhaft, Robert; Graham, Gwenda J; Laurence, Rita G; Frangioni, John V

    2009-07-01

    We have developed an image-guided surgical system based on invisible near-infrared fluorescent light. Presently, the only clinically available near-infrared fluorophore is indocyanine green, which fluoresces at approximately 800 nm and is used for coronary angiography. Our objective was to determine whether methylene blue, already US Food and Drug Administration approved for other indications, has useful near-infrared fluorescence properties for image-guided cardiac surgery. The optical properties of methylene blue were measured after dissolution in 100% serum. Biodistribution and clearance were quantified in organs and tissue after intravenous bolus injection of 2 mg/kg methylene blue in 3 rats. Coronary arteriography and cardiac perfusion were imaged in real time after intravenous bolus injection of 1 mg/kg methylene blue in 5 pigs with coronary obstructions. Coronary angiography and acute thrombi were assessed by using 800-nm fluorophores, indocyanine green, and IR-786-labeled platelets, respectively. The peak absorbance and emission of methylene blue as a near-infrared fluorophore occur at 667 nm and 686 nm, respectively. After intravenous injection, methylene blue provides highly sensitive coronary angiography. A lipophilic cation, methylene blue is extracted rapidly into tissue, with myocardium displaying unusually high uptake. Methylene blue permits real-time visualization and quantitative assessment of myocardial perfusion. Because of absent spectral overlap, use of 2 independent fluorophores in our imaging system permits simultaneous quantification of perfusion, venous drainage, and/or intravascular thrombi. Methylene blue is an effective near-infrared fluorophore that provides direct visualization of coronary arteriography and cardiac perfusion. In conjunction with approximately 800-nm near-infrared fluorophores, important functional assessments during cardiac surgery are also possible.

  20. Real-Time Assessment of Cardiac Perfusion, Coronary Angiography, and Acute Intravascular Thrombi Using Dual-Channel Near-Infrared Fluorescence Imaging

    PubMed Central

    Tanaka, Eiichi; Chen, Frederick Y.; Flaumenhaft, Robert; Graham, Gwenda J.; Laurence, Rita G.; Frangioni, John V.

    2009-01-01

    Objectives We have developed an image-guided surgery system based on invisible near-infrared (NIR) fluorescent light. Presently, the only clinically-available NIR fluorophore is indocyanine green (ICG), which fluoresces at ≈ 800 nm and is used for coronary angiography. Our objective was to determine if methylene blue (MB), already FDA-approved for other indications, has useful NIR fluorescence properties for image-guided cardiac surgery. Methods The optical properties of MB were measured after dissolution in 100% serum. Biodistribution and clearance were quantified in organs and tissues after intravenous bolus injection of 2 mg/kg MB in N = 3 rats. Coronary arteriography and cardiac perfusion were imaged in real-time after intravenous bolus injection of 1 mg/kg MB in N = 5 pigs with coronary obstructions. Coronary angiography and acute thrombi were assessed using 800 nm fluorophores, ICG and IR-786-labeled platelets, respectively. Results The peak absorbance and emission of MB as a NIR fluorophore occur at 667 nm and 686 nm, respectively. After intravenous injection, MB provides highly sensitive coronary angiography. A lipophilic cation, MB is extracted rapidly into tissue, with myocardium displaying unusually high uptake. MB permits real-time visualization and quantitative assessment of myocardial perfusion. Because of absent spectral overlap, use of two independent fluorophores on our imaging system permits simultaneous quantification of perfusion, venous drainage and/or intravascular thrombi. Conclusions MB is an effective NIR fluorophore that provides direct visualization of coronary arteriography and cardiac perfusion. In conjunction with ≈ 800 nm NIR fluorophores, important functional assessments during cardiac surgery are also possible. PMID:19577070

  1. Real-time distributed measurement of detonation velocities inside high explosives with the help of chirped fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Magne, Sylvain; Lefrançois, Alexandre; Luc, Jérome; Laffont, Guillaume; Ferdinand, Pierre

    2013-05-01

    Following the pioneering work of the Lawrence Livermore National Laboratory, Chirped Fiber Bragg Gratings are investigated as in situ, real-time, wavelength-position discriminators for measuring detonation speeds inside explosives.

  2. Hands-free, wireless goggles for near-infrared fluorescence and real-time image-guided surgery.

    PubMed

    Liu, Yang; Bauer, Adam Q; Akers, Walter J; Sudlow, Gail; Liang, Kexian; Shen, Duanwen; Berezin, Mikhail Y; Culver, Joseph P; Achilefu, Samuel

    2011-05-01

    Current cancer management faces several challenges, including the occurrence of a residual tumor after resection, the use of radioactive materials or high concentrations of blue dyes for sentinel lymph node biopsy, and the use of bulky systems in surgical suites for image guidance. To overcome these limitations, we developed a real-time, intraoperative imaging device that, when combined with near infrared fluorescent molecular probes, can aid in the identification of tumor margins, guide surgical resections, map sentinel lymph nodes, and transfer acquired data wirelessly for remote analysis. We developed a new compact, wireless, wearable, and battery-operated device that allows for hands-free operation by surgeons. A charge-coupled device-based, consumer-grade night vision viewer was used to develop the detector portion of the device, and the light source portion was developed from a compact headlamp. This piece was retrofitted to provide both near infrared excitation and white light illumination simultaneously. Wireless communication was enabled by integrating a battery-operated, miniature, radio-frequency video transmitter into the system. We applied the device in several types of oncologic surgical procedures in murine models, including sentinel lymph node mapping, fluorescence-guided tumor resection, and surgery under remote expert guidance. Unlike conventional imaging instruments, the device displays fluorescence information directly on its eyepiece. When employed in sentinel lymph node mapping, the locations of sentinel lymph nodes were visualized clearly, even with tracer level dosing of a near infrared fluorescent dye (indocyanine green). When used in tumor resection, tumor margins and small nodules invisible to the naked eye were visualized readily. In a simulated, point-of-care setting, tumors were located successfully and removed under remote guidance using the wireless feature of the device. Importantly, the total cost of this prototype system ($1200

  3. [Research of real-time fluorescent PCR in the rapid differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines].

    PubMed

    Han, Jian-Feng; Ning, Yi-Bao; Song, Li; Yang, Cheng-Huai

    2007-09-01

    Specific primers and TaqMan MGB probes were designed with Primer Express 2.0 software according to the conserved region of the H5, H9, H7 subtype AIV hemagglutinin gene to make research of real-time fluorescent one-step PCR in the differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines. The result showed that the method was specific and reproducible. No cross-reaction was discovered with other avian disease vaccines. Real-time fluorescent PCR provided a specific, sensitive, rapid and convenient method for the subtype identification of avian influenza inactivated vaccines.

  4. Enumeration of Archaea and Bacteria in seafloor basalt using real-time quantitative PCR and fluorescence microscopy.

    PubMed

    Einen, Jørn; Thorseth, Ingunn H; Ovreås, Lise

    2008-05-01

    A SYBR Green real-time quantitative PCR (Q-PCR) assay for the detection and quantification of Bacteria and Archaea present in the glassy rind of seafloor basalts of different ages and water depths is presented. Two sets of domain-specific primers were designed and validated for specific detection and quantification of bacterial and archaeal 16S rRNA genes in DNA extracted from basaltic glass. Total cell numbers were also estimated by fluorescence microscopy analysis of SYBR Gold-stained samples. The results from the two different approaches were concurrent, and Q-PCR results showed that the total number of cells present in basalts was in the range from 6 x 10(5) to 4 x 10(6) cells g(-1) basaltic glass. Further, it was demonstrated that these cells were almost exclusively from the domain Bacteria. When applying the same methods on samples of different ages (22 years-0.1 Ma) and water depths (139-3390 mbsl), no significant differences in cell concentrations or in the relative abundance of Archaea and Bacteria were detected.

  5. Visualization of feline calicivirus replication in real-time with recombinant viruses engineered to express fluorescent reporter proteins.

    PubMed

    Abente, Eugenio J; Sosnovtsev, Stanislav V; Bok, Karin; Green, Kim Y

    2010-04-25

    Caliciviruses are non-enveloped, icosahedral viruses with a single-stranded, positive sense RNA genome. Transposon-mediated insertional mutagenesis was used to insert a transprimer sequence into random sites of an infectious full-length cDNA clone of the feline calicivirus (FCV) genome. A site in the LC gene (encoding the capsid leader protein) of the FCV genome was identified that could tolerate foreign insertions, and two viable recombinant FCV variants expressing LC fused either to AcGFP, or DsRedFP were recovered. The effects of the insertions on LC processing, RNA replication, and stability of the viral genome were analyzed, and the progression of a calicivirus single infection and co-infection were captured by real-time imaging fluorescent microscopy. The ability to engineer viable recombinant caliciviruses expressing foreign markers enables new approaches to investigate virus and host cell interactions, as well as studies of viral recombination, one of the driving forces of calicivirus evolution. Published by Elsevier Inc.

  6. Real-time, Spatially Resolved Analysis of Serotonin Transporter Activity And Regulation Using the Fluorescent Substrate, ASP+

    PubMed Central

    Oz, M.; Libby, T.; Kivell, B.; Jaligam, V.; Ramamoorthy, S.; Shippenberg, T.S.

    2010-01-01

    The serotonin transporter (SERT) mediates clearance of serotonin from the synapse, thereby, regulating extracellular serotonin concentrations. Radioligand uptake techniques are typically used to assess SERT function in tissue and heterologous expression systems. The need for sufficient protein in samples, however, requires use of homogenate preparations, potentially masking effects limited to specific cell populations. 4-(4-(dimethylamino)-styryl)-N-methylpyridinium (ASP+) is a fluorescent monoamine transporter substrate that has been used for real-time monitoring of dopamine and norepinephrine transporter function in single cells. The present live cell imaging studies examine the utility of ASP+ for quantifying hSERT function in HEK-293 and neuroblastoma cells. We show rapid membrane binding and intracellular ASP+ accumulation in hSERT expressing cells. Accumulation is saturable; dependent on temperature and the presence of sodium and chloride in the media, and attenuated by serotonin. Acute or prolonged exposure of cells to serotonin re-uptake inhibitors produces a concentration-dependent decrease in accumulation. Similar effects are produced by PKC activation whereas p38MAPK activation increases ASP+ accumulation. These data demonstrate the validity of ASP+ as a probe for monitoring SERT function in living cells. Alterations in SERT binding and uptake can be quantified in the same cell and use of a within cell design permits analysis of time-related alterations in SERT function. PMID:20524964

  7. [Detection of Mycobacterium tuberculosis complex in paraffin-embedded tissues by real-time fluorescent quantitative polymerase chain reaction].

    PubMed

    Ye, Feng; Chen, Yu; He, Du; Jian, Shu-yu; Zheng, Ke; Li, Gan-di; Bu, Hong

    2013-08-01

    To investigate the feasibility of real-time fluorescent quantitative (qPCR) assay in detecting mycobacterium tuberculosis complex (MTB) in paraffin embedded tissues for diagnostic purpose. Using qPCR assay, 1000 consecutive formalin-fixed and paraffin embedded (FFPE) tissues (from 2011 to 2012) suspected of MTB infection were tested by amplifying the MTB specific insertion sequence 6110 (IS6110). The specificity of the PCR product was confirmed by Sanger sequencing as compared with the MTB genomic DNA of the IS6110 sequence. Tissues with Ziehl-Neelsen acid-fast staining were used as control. In the 1000 samples, 513 were positive for mycobacterium by Ziehl-Neelsen acid-fast staining (detection rate 51.3%); whereas 546 were MTB positive by qPCR assay (detection rate 54.6%). Concordance rate for both assays was 73.1%. The diagnosis rate increased by 14.4% by combinination of Ziehl-Neelsen acid-fast staining and qPCR results. More interestingly, by analyzing the Ziehl-Neelsen acid-fast staining and qPCR results three cases of M.leprae infection and four cases of non-tuberculous Mycobacterium (NTM) infection were identified. qPCR detection of MTB in FFPE tissue is more sensitive than Ziehl-Neelsen acid-fast staining assay. Combination of these two assays can increase the detection rate and also identify some rare cases of NTM infection.

  8. In situ method for real time measurement of dielectric film thickness in plasmas

    SciTech Connect

    Jang, Sung-Ho; Kim, Gun-Ho; Chung, Chin-Wook

    2010-01-15

    An in situ thickness measurement method of dielectric films (dual frequency method) was developed, and the thicknesses were measured in an inductively coupled plasma. This method uses a small ac bias voltage with two frequencies for thickness measurement. The dielectric thickness is obtained from measuring the amplitudes of the two frequency ac currents through a sensor, as well as using an equivalent circuit model describing impedance of the dielectric film and the plasma sheath. In the experiment, the thicknesses of Al{sub 2}O{sub 3} film could be accurately measured in real time. To check the measurement reliability, the dual frequency method was compared with reflection spectrophotometry as a technique for optical thickness diagnostics. It was found that the dual frequency method agrees closely with reflection spectrophotometry at various rf powers and pressures. In addition, this method is very simple and can be installed anywhere in plasma reactors, in contrast with optical methods; therefore, it is expected to be applied to in situ surface diagnostics for various processing plasmas.

  9. Ratiometric fluorescent response of electrospun fibrous strips for real-time sensing of alkaline phosphatase in serum.

    PubMed

    Zhao, Long; Xie, Songzhi; Song, Xiaojie; Wei, Jiaojun; Zhang, Zhao; Li, Xiaohong

    2017-05-15

    The development of rapid, convenient and reliable assays for monitoring alkaline phosphatase (ALP) levels is valuable for clinical diagnoses and biomedical research. In the current study, a ratiometric assay of ALP activity has been realized by covalent immobilization of fluorescein onto polyethylene terephthalate (PET) fibers, followed by electrostatic adsorption of bisquaternary ammonium salt of tetraphenylethene (TPE-2N(+)). In the absence of ALP, the complex formation between phosphorylated fluorescein and TPE-2N(+) results in the aggregation-induced emission (AIE) of TPE at 471nm. While in the presence of ALP, the hydrolysis of phosphoesters leads to a gradual removal of TPE-2N(+) and the restoration of fluorescein emission at 514nm. Fibers with surface amine densities of 30 nmol/mg show the most significant and almost linear increases in I514/I471 ratios from 0.73 to 3.05 with increasing ALP concentrations from 0 to 100 mU/mL. The ratiometric fluorescence responses result in color changes of fibrous strips from blue (TPE-2N(+)) to green (fluorescein) under an ultraviolet lamp in a matter of minutes. The color changes are more suitable for an eyeball detection of ALP levels ranging from 0 to 80 mU/mL, which is included in the concentration range of ALP in human serum considering the dilution factor if necessary. The ALP detection indicates no apparent interference by serum components and good agreement with enzyme-linked immunosorbent assay (ELISA). Thus, this is the first study on ratiometric fluorescent assay of serum ALP levels by fibrous strips, which offers a capacity to exploit electrospun fibrous mats and ratiometric responses for real-time assays of bioactive substances as self-test devices.

  10. Best Practice for Rainfall Measurement, Torrential Flood Monitoring and Real Time Alerting System in Serbia

    NASA Astrophysics Data System (ADS)

    Stefanovic, Milutin; Milojevic, Mileta; Zlatanovic, Nikola

    2014-05-01

    Serbia occupies 88.000 km2 and its confined zone menaced with torrent flood occupies 50.000km2. Floods on large rivers and torrents are the most frequent natural disasters in Serbia. This is the result of a geographic position and relief of Serbia. Therefore, defense from these natural disasters has been institutionalized since the 19th century. Through its specialized bodies and public companies, the State organized defense from floods on large rivers and protection of international and other main roads. The Topčiderska River is one of a number of rivers in Serbia that is a threat to both urban and rural environments. In this text, general characteristics of this river will be illustrated, as well as the historical natural hazards that have occurred in the part of Belgrade near Topčiderska River. Belgrade is the capital of Serbia, its political, administrative and financial center, which means that there are significant financial capacities and human resources for investments in all sectors, and specially in the water resources sector. Along the Topčiderska catchment there are many industrial, traffic and residential structures that are in danger of floods and flood protection is more difficult with rapid high flows. The goal is to use monitoring on the Topčiderska River basin to set up a modern system for monitoring in real time and forecast of torrential floods. This paper represents a system of remote detection and monitoring of torrential floods and rain measurements in real time on Topciderka river and ready for a quick response.

  11. Real-time measurement of materials properties at high temperatures by laser produced plasmas

    NASA Technical Reports Server (NTRS)

    Kim, Yong W.

    1990-01-01

    Determination of elemental composition and thermophysical properties of materials at high temperatures, as visualized in the context of containerless materials processing in a microgravity environment, presents a variety of unusual requirements owing to the thermal hazards and interferences from electromagnetic control fields. In addition, such information is intended for process control applications and thus the measurements must be real time in nature. A new technique is described which was developed for real time, in-situ determination of the elemental composition of molten metallic alloys such as specialty steel. The technique is based on time-resolved spectroscopy of a laser produced plasma (LPP) plume resulting from the interaction of a giant laser pulse with a material target. The sensitivity and precision were demonstrated to be comparable to, or better than, the conventional methods of analysis which are applicable only to post-mortem specimens sampled from a molten metal pool. The LPP technique can be applied widely to other materials composition analysis applications. The LPP technique is extremely information rich and therefore provides opportunities for extracting other physical properties in addition to the materials composition. The case in point is that it is possible to determine thermophysical properties of the target materials at high temperatures by monitoring generation and transport of acoustic pulses as well as a number of other fluid-dynamic processes triggered by the LPP event. By manipulation of the scaling properties of the laser-matter interaction, many different kinds of flow events, ranging from shock waves to surface waves to flow induced instabilities, can be generated in a controllable manner. Time-resolved detection of these events can lead to such thermophysical quantities as volume and shear viscosities, thermal conductivity, specific heat, mass density, and others.

  12. Blood purine measurements as a rapid real-time indicator of reversible brain ischaemia.

    PubMed

    Tian, Faming; Bibi, Fakhra; Dale, Nicholas; Imray, Christopher H E

    2017-08-12

    To preserve the disequilibrium between ATP and ADP necessary to drive cellular metabolism, enzymatic pathways rapidly convert ADP to adenosine and the downstream purines inosine and hypoxanthine. During ischaemia, these same pathways result in the production of purines. We performed a prospective observational study to test whether purine levels in arterial blood might correlate with brain ischaemia. We made real-time perioperative measurements, via microelectrode biosensors, of the purine levels in untreated arterial blood from 18 patients undergoing regional anaesthetic carotid endarterectomy. Pre-operatively, the median purine level was 2.4 μM (95% CI 1.3-4.0 μM); during the cross-clamp phase, the purines rose to 6.7 μM (95% CI 4.7-11.5 μM) and fell back to 1.9 μM (95% CI 1.4-2.7 μM) in recovery. Three patients became unconscious during carotid clamping, necessitating insertion of a temporary carotid shunt to restore cerebral blood flow. In these, the pre-operative median purine level was 5.4 μM (range 4.7-6.1 μM), on clamping, 9.6 μM (range 9.4-16.1 μM); during shunting, purines fell to below the pre-operative level (1.4 μM, range 0.4-2.9 μM) and in recovery 1.8 μM (range 1.8-2.6 μM). Our results suggest that blood purines may be a sensitive real-time and rapidly produced indicator of brain ischaemia, even when there is no accompanying neurological obtundation.

  13. Environmental measurement while drilling system for real-time field screening of contaminants

    SciTech Connect

    Williams, C.V.; Lockwood, G.J.; Normann, R.A.

    1996-12-31

    Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of subsurface contaminants. Real-time information on environmental conditions, drill bit location and temperature during drilling is valuable in many environmental restoration operations. This type of information can be used to provide field screening data and improved efficiency of site characterization activities. The Environmental Measurement-While-Drilling (EMWD) System represents an innovative blending of new and existing technology in order to obtain real-time data during drilling. The system consists of two subsystems. The down-hole subsystem (at the drill bit) consists of sensors, a power supply, a signal conditioning and transmitter board, and a radio-frequency (RF) coaxial cable. The up-hole subsystem consists of a battery pack/coil, pickup coil, receiver, and personal computer. The system is compatible with fluid miser drill pipe, a directional drilling technique that uses minimal drilling fluids and generates little to no secondary waste. In EMWD, downhole sensors are located behind the drill bit and linked by a high-speed data transmission system to a computer at the surface. As drilling is conducted, data is collected on the nature and extent of contamination, enabling on-the-spot decisions regarding drilling and sampling strategies. Initially, the downhole sensor consisted of a simple gamma radiation detector, a Geiger-Mueller tube (GMT). The EMWD system has been improved by the integration of a Gamma Ray Spectrometer (GRS) in place of the GMT. The GRS consists of a sodium iodide-thallium activated crystal coupled to a photomultiplier tube (PMT). The output of the PMT goes to a multichannel analyzer (MCA). The MCA data is transmitted to the surface via a signal conditioning and transmitter board similar to that used with the GMT. The EMWD system is described and the results of the GRS field tests and field demonstration are presented.

  14. G-quadruplex fluorescent probe-mediated real-time rolling circle amplification strategy for highly sensitive microRNA detection.

    PubMed

    Jiang, Hong-Xin; Liang, Zhen-Zhen; Ma, Yan-Hong; Kong, De-Ming; Hong, Zhang-Yong

    2016-11-02

    Real-time PCR has revolutionized PCR from qualitative to quantitative. As an isothermal DNA amplification technique, rolling circular amplification (RCA) has been demonstrated to be a versatile tool in many fields. Development of a simple, highly sensitive, and specific strategy for real-time monitoring of RCA will increase its usefulness in many fields. The strategy reported here utilized the specific fluorescence response of thioflavin T (ThT) to G-quadruplexes formed by RCA products. Such a real-time monitoring strategy works well in both traditional RCA with linear amplification efficiency and modified RCA proceeded in an exponential manner, and can be readily performed in commercially available real-time PCR instruments, thereby achieving high-throughput detection and making the proposed technique more suitable for biosensing applications. As examples, real-time RCA-based sensing platforms were designed and successfully used for quantitation of microRNA over broad linear ranges (8 orders of magnitude) with a detection limit of 4 aM (or 0.12 zmol). The feasibility of microRNA analysis in human lung cancer cells was also demonstrated. This work provides a new method for real-time monitoring of RCA by using unique nucleic acid secondary structures and their specific fluorescent probes. It has the potential to be extended to other isothermal single-stranded DNA amplification techniques.

  15. Real-Time Measurement of Width and Height of Weld Beads in GMAW Processes.

    PubMed

    Pinto-Lopera, Jesús Emilio; S T Motta, José Mauricio; Absi Alfaro, Sadek Crisostomo

    2016-09-15

    Associated to the weld quality, the weld bead geometry is one of the most important parameters in welding processes. It is a significant requirement in a welding project, especially in automatic welding systems where a specific width, height, or penetration of weld bead is needed. This paper presents a novel technique for real-time measuring of the width and height of weld beads in gas metal arc welding (GMAW) using a single high-speed camera and a long-pass optical filter in a passive vision system. The measuring method is based on digital image processing techniques and the image calibration process is based on projective transformations. The measurement process takes less than 3 milliseconds per image, which allows a transfer rate of more than 300 frames per second. The proposed methodology can be used in any metal transfer mode of a gas metal arc welding process and does not have occlusion problems. The responses of the measurement system, presented here, are in a good agreement with off-line data collected by a common laser-based 3D scanner. Each measurement is compare using a statistical Welch's t-test of the null hypothesis, which, in any case, does not exceed the threshold of significance level α = 0.01, validating the results and the performance of the proposed vision system.

  16. Real-time measurements of suspended sediment concentration and particle size using five techniques

    NASA Astrophysics Data System (ADS)

    Felix, D.; Albayrak, I.; Abgottspon, A.; Boes, R. M.

    2016-11-01

    Fine sediments are important in the design and operation of hydropower plants (HPPs), in particular with respect to sediment management and hydro-abrasive erosion in hydraulic machines. Therefore, there is a need for reliable real-time measurements of suspended sediment mass concentration (SSC) and particle size distribution (PSD). The following instruments for SSC measurements were investigated in a field study during several years at the HPP Fieschertal in the Swiss Alps: (1) turbidimeters, (2) a Laser In-Situ Scattering and Trans- missometry instrument (LISST), (3) a Coriolis Flow and Density Meter (CFDM), (4) acoustic transducers, and (5) pressure sensors. LISST provided PSDs in addition to concentrations. Reference SSCs were obtained by gravimetrical analysis of automatically taken water samples. In contrast to widely used turbidimeters and the single-frequency acoustic method, SSCs obtained from LISST, the CFDM or the pressure sensors were less or not affected by particle size variations. The CFDM and the pressure sensors allowed measuring higher SSC than the optical or the acoustic techniques (without dilution). The CFDM and the pressure sensors were found to be suitable to measure SSC ≥ 2 g/l. In this paper, the measuring techniques, instruments, setup, methods for data treatment, and selected results are presented and discussed.

  17. Real-Time Measurement of Width and Height of Weld Beads in GMAW Processes

    PubMed Central

    Pinto-Lopera, Jesús Emilio; S. T. Motta, José Mauricio; Absi Alfaro, Sadek Crisostomo

    2016-01-01

    Associated to the weld quality, the weld bead geometry is one of the most important parameters in welding processes. It is a significant requirement in a welding project, especially in automatic welding systems where a specific width, height, or penetration of weld bead is needed. This paper presents a novel technique for real-time measuring of the width and height of weld beads in gas metal arc welding (GMAW) using a single high-speed camera and a long-pass optical filter in a passive vision system. The measuring method is based on digital image processing techniques and the image calibration process is based on projective transformations. The measurement process takes less than 3 milliseconds per image, which allows a transfer rate of more than 300 frames per second. The proposed methodology can be used in any metal transfer mode of a gas metal arc welding process and does not have occlusion problems. The responses of the measurement system, presented here, are in a good agreement with off-line data collected by a common laser-based 3D scanner. Each measurement is compare using a statistical Welch’s t-test of the null hypothesis, which, in any case, does not exceed the threshold of significance level α = 0.01, validating the results and the performance of the proposed vision system. PMID:27649198

  18. Real-time intraoperative assessment of the extrahepatic bile ducts in rats and pigs using invisible near-infrared fluorescent light.

    PubMed

    Tanaka, Eiichi; Choi, Hak Soo; Humblet, Valerie; Ohnishi, Shunsuke; Laurence, Rita G; Frangioni, John V

    2008-07-01

    Currently, only x-ray fluoroscopy is available for visualization of the extrahepatic bile ducts intraoperatively. We hypothesized that with an appropriate fluorophore and imaging system, invisible near-infrared (NIR) light could be used for image-guided procedures on the extrahepatic bile ducts. We quantified the performance of three 800 nm NIR fluorophores, differing primarily in their degree of hydrophilicity, for real-time imaging of the extrahepatic bile ducts in rats and pigs: IR-786, indocyanine green (ICG), and the carboxylic form of IRDyetrade mark 800CW (CW800-CA). The signal-to-background ratio (SBR) of the common bile duct relative to liver and pancreas was measured as a function of the dose of contrast agent, injection site, and kinetics using an intraoperative NIR fluorescence imaging system described previously. Bile samples were examined by high performance liquid chromatography tandem mass spectrometry (HPLC/MS) to determine the chemical form of fluorophores in bile. Non-sulfonated (IR-786) and di-sulfonated (ICG) NIR fluorophores had poor efficiency and kinetics of excretion into bile. Tetra-sulfonated CW800-CA, however, provided sensitive, specific, and real-time visualization of the extrahepatic bile ducts after a single low-dose given either intraportally or intravenously via systemic vein. A SBR >/=2 provided sensitive assessment of extrahepatic bile duct anatomy and function for over 30 min post-injection, including the detection of millimeter-sized, radiolucent inclusions in pigs. CW800-CA remained intact chemically after secretion into bile. The combination of invisible NIR light and an IV injection of CW800-CA provides prolonged, real-time visualization of the extrahepatic bile duct, without ionizing radiation and without changing the look of the operative field.

  19. Spatiotemporal effects of sonoporation measured by real-time calcium imaging.

    PubMed

    Kumon, R E; Aehle, M; Sabens, D; Parikh, P; Han, Y W; Kourennyi, D; Deng, C X

    2009-03-01

    To investigate the effects of sonoporation, spatiotemporal evolution of ultrasound-induced changes in intracellular calcium ion concentration ([Ca(2+)](i)) was determined using real-time fura-2AM fluorescence imaging. Monolayers of Chinese hamster ovary (CHO) cells were exposed to a 1-MHz ultrasound tone burst (0.2 s, 0.45 MPa) in the presence of Optison microbubbles. At extracellular [Ca(2+)](o) of 0.9 mM, ultrasound application generated both nonoscillating and oscillating (periods 12 to 30 s) transients (changes of [Ca(2+)](i) in time) with durations of 100-180 s. Immediate [Ca(2+)](i) transients after ultrasound application were induced by ultrasound-mediated microbubble-cell interactions. In some cases, the immediately affected cells did not return to pre-ultrasound equilibrium [Ca(2+)](i) levels, thereby indicating irreversible membrane damage. Spatial evolution of [Ca(2+)](i) in different cells formed a calcium wave that was observed to propagate outward from the immediately affected cells at 7-20 microm/s over a distance >200 microm, causing delayed transients in cells to occur sometimes 60 s or more after ultrasound application. In calcium-free solution, ultrasound-affected cells did not recover, consistent with the requirement of extracellular Ca(2+) for cell membrane recovery subsequent to sonoporation. In summary, ultrasound application in the presence of Optison microbubbles can generate transient [Ca(2+)](i) changes and oscillations at a focal site and in surrounding cells via calcium waves that last longer than the ultrasound duration and spread beyond the focal site. These results demonstrate the complexity of downstream effects of sonoporation beyond the initial pore formation and subsequent diffusion-related transport through the cellular membrane.

  20. Continuous-flow water sampler for real-time isotopic water measurements

    NASA Astrophysics Data System (ADS)

    Carter, J.; Dennis, K.

    2013-12-01

    Measuring the stable isotopes of liquid water (δ18O and δD) is a tool familiar to many Earth scientists, but most current techniques require discrete sampling. For example, isotope ratio mass spectrometry requires the collection of aliquots of water that are then converted to CO2, CO or H2 for analysis. Similarly, laser-based techniques, such as Cavity Ring-Down Spectroscopy (CRDS) convert discrete samples (typically < 2μL) of liquid water to water vapor using a flash vaporization process. By requiring the use of discrete samples fine-scale spatial and temporal studies of changes in δ18O and δD are limited. Here we present a continuous-flow water sampler that will enable scientists to probe isotopic changes in real-time, with applications including, but not limited to, quantification of the 'amount effect' (Dansgaard, 1964) during an individual precipitation event or storm track, real-time mixing of water in river systems, and shipboard continuous water measurements (Munksgaard et al., 2012). Due to the inherent ability of CRDS to measure a continuous flow of water vapor it is an ideal candidate for interfacing with a continuous water sampling system. Here we present results from the first commercially available continuous-flow water sampler, developed by engineers at Picarro. This peripheral device is compatible with Picarro CRDS isotopic water analyzers, allowing real-time, continuous isotopic measurements of liquid water. The new device, which expands upon the design of Munskgaard et al. (2011), utilizes expanded polytetrafluoroethylene (ePTFE) membrane technology to continuously generate gas-phase water, while liquid water is pumped through the system. The water vapor subsequently travels to the CRDS analyzer where the isotopic ratios are measured and recorded. The generation of water vapor using membrane technology is sensitive to environmental conditions, which if not actively control, lead to sustainable experimental noise and drift. Consequently, our

  1. Ultrafast NMR T1 relaxation measurements: probing molecular properties in real time.

    PubMed

    Smith, Pieter E S; Donovan, Kevin J; Szekely, Or; Baias, Maria; Frydman, Lucio

    2013-09-16

    The longitudinal relaxation properties of NMR active nuclei carry useful information about the site-specific chemical environments and about the mobility of molecular fragments. Molecular mobility is in turn a key parameter reporting both on stable properties, such as size, as well as on dynamic ones, such as transient interactions and irreversible aggregation. In order to fully investigate the latter, a fast sampling of the relaxation parameters of transiently formed molecular species may be needed. Nevertheless, the acquisition of longitudinal relaxation data is typically slow, being limited by the requirement that the time for which the nucleus relaxes be varied incrementally until a complete build-up curve is generated. Recently, a number of single-shot-inversion-recovery methods have been developed capable of alleviating this need; still, these may be challenged by either spectral resolution restrictions or when coping with very fast relaxing nuclei. Here, we present a new experiment to measure the T1s of multiple nuclear spins that experience fast longitudinal relaxation, while retaining full high-resolution chemical shift information. Good agreement is observed between T1s measured with conventional means and T1s measured using the new technique. The method is applied to the real-time investigation of the reaction between D-xylose and sodium borate, which is in turn elucidated with the aid of ancillary ultrafast and conventional 2D TOCSY measurements. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. In-Line Capacitance Sensor for Real-Time Water Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Nurge, Mark A.; Perusich, Stephen A.

    2010-01-01

    A capacitance/dielectric sensor was designed, constructed, and used to measure in real time the in-situ water concentration in a desiccant water bed. Measurements were carried out with two experimental setups: (1) passing nitrogen through a humidity generator and allowing the gas stream to become saturated at a measured temperature and pressure, and (2) injecting water via a syringe pump into a nitrogen stream. Both water vapor generating devices were attached to a downstream vertically-mounted water capture bed filled with 19.5 g of Moisture Gone desiccant. The sensor consisted of two electrodes: (1) a 1/8" dia stainless steel rod placed in the middle of the bed and (2) the outer shell of the stainless steel bed concentric with the rod. All phases of the water capture process (background, heating, absorption, desorption, and cooling) were monitored with capacitance. The measured capacitance was found to vary linearly with the water content in the bed at frequencies above 100 kHz indicating dipolar motion dominated the signal; below this frequency, ionic motion caused nonlinearities in the water concentration/capacitance relationship. The desiccant exhibited a dielectric relaxation whose activation energy was lowered upon addition of water indicating either a less hindered rotational motion or crystal reorientation.

  3. Real-Time Observation of Platinum Redispersion on Ceria-Based Oxide by In-situ Turbo-XAS in Fluorescence Mode

    SciTech Connect

    Nagai, Yasutaka; Dohmae, Kazuhiko; Tanabe, Toshitaka; Shinjoh, Hirofumi; Takagi, Nobuyuki; Ikeda, Yasuo; Guilera, Gemma; Pascarelli, Sakura; Newton, Mark; Matsumoto, Shin'ichi

    2007-02-02

    A real-time observation of the redispersion behavior of sintered Pt on ceria-based oxide was made possible by in-situ time-resolved Turbo-XAS in fluorescence mode. 2 wt% Pt/Ce-Zr-Y mixed oxide samples were prepared, and then treated under an aging condition. The average Pt particle size measured by CO absorption method after aging was 7 nm. Redispersion treatments of the previously aged catalyst were carried out at 600 deg. C within an in-situ XAS cell in a cyclical flow of reducing/oxidizing gases. Pt L3-edge XANES spectra were collected every 1.1 second under in-situ conditions. From a change in the XANES spectra, we observed that the Pt particle size of the aged catalyst decreased from 7 to 5 nm after 60 seconds and then to 3 nm after 1000 seconds.

  4. Real-time microscopic 3D shape measurement based on optimized pulse-width-modulation binary fringe projection

    NASA Astrophysics Data System (ADS)

    Hu, Yan; Chen, Qian; Feng, Shijie; Tao, Tianyang; Li, Hui; Zuo, Chao

    2017-07-01

    In recent years, tremendous progress has been made in 3D measurement techniques, contributing to the realization of faster and more accurate 3D measurement. As a representative of these techniques, fringe projection profilometry (FPP) has become a commonly used method for real-time 3D measurement, such as real-time quality control and online inspection. To date, most related research has been concerned with macroscopic 3D measurement, but microscopic 3D measurement, especially real-time microscopic 3D measurement, is rarely reported. However, microscopic 3D measurement plays an important role in 3D metrology and is indispensable in some applications in measuring micro scale objects like the accurate metrology of MEMS components of the final devices to ensure their proper performance. In this paper, we proposed a method which effectively combines optimized binary structured patterns with a number-theoretical phase unwrapping algorithm to realize real-time microscopic 3D measurement. A slight defocusing of our optimized binary patterns can considerably alleviate the measurement error based on four-step phase-shifting FPP, providing the binary patterns with a comparable performance to ideal sinusoidal patterns. The static measurement accuracy can reach 8 μm, and the experimental results of a vibrating earphone diaphragm reveal that our system can successfully realize real-time 3D measurement of 120 frames per second (FPS) with a measurement range of 8~\\text{mm}× 6~\\text{mm} in lateral and 8 mm in depth.

  5. Application of the Nordtest method for "real-time" uncertainty estimation of on-line field measurement.

    PubMed

    Näykki, Teemu; Virtanen, Atte; Kaukonen, Lari; Magnusson, Bertil; Väisänen, Tero; Leito, Ivo

    2015-10-01

    Field sensor measurements are becoming more common for environmental monitoring. Solutions for enhancing reliability, i.e. knowledge of the measurement uncertainty of field measurements, are urgently needed. Real-time estimations of measurement uncertainty for field measurement have not previously been published, and in this paper, a novel approach to the automated turbidity measuring system with an application for "real-time" uncertainty estimation is outlined based on the Nordtest handbook's measurement uncertainty estimation principles. The term real-time is written in quotation marks, since the calculation of the uncertainty is carried out using a set of past measurement results. There are two main requirements for the estimation of real-time measurement uncertainty of online field measurement described in this paper: (1) setting up an automated measuring system that can be (preferably remotely) controlled which measures the samples (water to be investigated as well as synthetic control samples) the way the user has programmed it and stores the results in a database, (2) setting up automated data processing (software) where the measurement uncertainty is calculated from the data produced by the automated measuring system. When control samples with a known value or concentration are measured regularly, any instrumental drift can be detected. An additional benefit is that small drift can be taken into account (in real-time) as a bias value in the measurement uncertainty calculation, and if the drift is high, the measurement results of the control samples can be used for real-time recalibration of the measuring device. The procedure described in this paper is not restricted to turbidity measurements, but it will enable measurement uncertainty estimation for any kind of automated measuring system that performs sequential measurements of routine samples and control samples/reference materials in a similar way as described in this paper.

  6. Real-time Monitoring of Dissolved Organic Matter (DOM) Amount, Composition, Source and Reactivity Using Fluorescence Spectroscopy: Applications for Drinking Water Quality

    NASA Astrophysics Data System (ADS)

    Kraus, T. E.; Saraceno, J.; Downing, B. D.; Goldman, J. H.; Carpenter, K. D.; McGhee, G.; Bergamaschi, B. A.

    2010-12-01

    There is growing interest in the use of in situ, continuous fluorescence spectroscopy as a proxy for dissolved organic carbon (DOC) concentration. To date, in situ fluorometers designed to estimate DOC concentration are single wavelength sensors centered near the excitation/emission (ex/em) pair 370/460 nm. Additional information about dissolved organic matter (DOM) composition has only been obtainable from benchtop fluorometers that provide multi-spectral data. Changes in DOM composition are important as they provide insight into DOM source (e.g. terrestrial, algal, wastewater) and reactivity. Recent advances in sensor technology make it possible to build in situ instruments for measuring multiple fluorescence ex/em pairs, including pairs with excitations in the lower “deep UV” region (e.g. 270/340 nm) associated with fresher and more labile DOM pools. The deployment of multi-spectral sensors will provide real-time continuous data showing not only changes in DOM concentration, but also changes in composition. This information is particularly pertinent to drinking water utilities because a fraction of DOM reacts upon disinfection (e.g. chlorination and ozonation) to form toxic disinfection byproducts (DBPs) which are regulated by the EPA. To test this application, we designed a multi-wavelength sensor that will measure three ex/em pairs (370/470, 370/520 and 270/340 nm) for deployment near a drinking water intake on the Clackamas River in Oregon. Comparison of the continuous data with discrete sample data indicates these tools can track both quantitative and qualitative changes in the DOM pool. The availability of this type of continuous data in real time could enable utilities to minimize the formation of DBPs by continuously optimizing treatment plant operations in response to changes in source water. In addition, collection of high-frequency data will improve understanding of watershed DOM dynamics and help identify sources of DOM and DBP precursors, thereby

  7. Real-time energy measurement of high repetition rate ultrashort laser pulses using pulse integration and FPGA processing.

    PubMed

    Tang, Qi-Jie; Yang, Dong-Xu; Wang, Jian; Feng, Yi; Zhang, Hong-Fei; Chen, Teng-Yun

    2016-11-01

    Real-time energy measurement using pulse integration method for high repetition rate ultrashort laser pulses based on FPGA (Field-Programmable Gate Array) and high-speed pipeline ADC (Analog-to-Digital Convertor) is introduced in this paper. There are two parts contained in this method: pulse integration and real-time data processing. The pulse integration circuit will convert the pulse to the step type signals which are linear to the laser pulse energy. Through the real-time data processing part, the amplitude of the step signals will be obtained by ADC sampling and conducting calculation in real time in FPGA. The test result shows that the method with good linearity (4.770%) and without pulse measurement missing is suitable for ultrashort laser pulses with high repetition rate up to 100 MHz.

  8. Real-time energy measurement of high repetition rate ultrashort laser pulses using pulse integration and FPGA processing

    NASA Astrophysics Data System (ADS)

    Tang, Qi-jie; Yang, Dong-xu; Wang, Jian; Feng, Yi; Zhang, Hong-fei; Chen, Teng-yun

    2016-11-01

    Real-time energy measurement using pulse integration method for high repetition rate ultrashort laser pulses based on FPGA (Field-Programmable Gate Array) and high-speed pipeline ADC (Analog-to-Digital Convertor) is introduced in this paper. There are two parts contained in this method: pulse integration and real-time data processing. The pulse integration circuit will convert the pulse to the step type signals which are linear to the laser pulse energy. Through the real-time data processing part, the amplitude of the step signals will be obtained by ADC sampling and conducting calculation in real time in FPGA. The test result shows that the method with good linearity (4.770%) and without pulse measurement missing is suitable for ultrashort laser pulses with high repetition rate up to 100 MHz.

  9. A cavity ring-down spectroscopy sensor for real-time Hall thruster erosion measurements.

    PubMed

    Lee, B C; Huang, W; Tao, L; Yamamoto, N; Gallimore, A D; Yalin, A P

    2014-05-01

    A continuous-wave cavity ring-down spectroscopy sensor for real-time measurements of sputtered boron from Hall thrusters has been developed. The sensor uses a continuous-wave frequency-quadrupled diode laser at 250 nm to probe ground state atomic boron sputtered from the boron nitride insulating channel. Validation results from a controlled setup using an ion beam and target showed good agreement with a simple finite-element model. Application of the sensor for measurements of two Hall thrusters, the H6 and SPT-70, is described. The H6 was tested at power levels ranging from 1.5 to 10 kW. Peak boron densities of 10 ± 2 × 10(14) m(-3) were measured in the thruster plume, and the estimated eroded channel volume agreed within a factor of 2 of profilometry. The SPT-70 was tested at 600 and 660 W, yielding peak boron densities of 7.2 ± 1.1 × 10(14) m(-3), and the estimated erosion rate agreed within ~20% of profilometry. Technical challenges associated with operating a high-finesse cavity in the presence of energetic plasma are also discussed.

  10. Real-time measurement of laser beam quality factor by the Fresnel phase-retrieval method

    NASA Astrophysics Data System (ADS)

    Yang, Pao-Keng; Liu, Jian-You; Chen, Yung-Chieh; Hsu, Chia-En

    2016-09-01

    Conventionally, it is a tedious work to measure the beam quality factor for a laser beam because one needs to move a camera-based beam profiler from one location to another for many times to record intensity profiles at different positions around the beam waist. We present a simple method for determining the laser beam quality factor from only two laser intensity profiles at different cross sections around the waist. We first used an iterative phase-retrieval algorithm, based on the Huygens-Fresnel principle, to reconstruct the phase profiles at the two cross sections where the intensity profiles had been measured. Once the optical field amplitude (the square root of intensity) and phase distribution functions at certain cross section of a laser beam had been determined, we can propagate the light wave at this cross section by using the Fresnel diffraction formula to obtain the intensity profiles at different positions, from which the beam quality factor can be determined. Using a HeNe laser for test, we had experimentally demonstrated the feasibility of our idea by showing that the result from our proposed method is in good agreement with that obtained from the conventional method. Our setup is capable of executing a real-time measurement of the beam quality factor because the two intensity profiles can be simultaneously recorded by using a beam splitter and two beam-profilers controlled by the same computer.

  11. Next generation optical surface sensing for real-time measurement in radiotherapy.

    PubMed

    Parkhurst, James M; Price, Gareth J; Sharrock, Phil J; Marchant, Tom E; Moore, Christopher J

    2011-01-01

    With the introduction of intensive new treatments such as hypo-fractionation and proton beam therapy, localization of the tumor target volume and tracking of points across the skin entrance surface have become critically important. Optical metrology has been used to monitor the patient's bulk position and motion throughout treatment. However systems have not been capable of high temporal and spatial resolution whole-surface topology measurement. We describe the implementation of such a system based on Fourier profilometry. Its algorithm is split into four separate processing stages, including spatial phase determination: descriptions of each stage are given along with the modifications made to increase performance. The optimized system is capable of processing 23 frames per second (fps), with each frame providing 512 × 512 measured points. The data density, accuracy and performance of the system are an order of magnitude improvement on commercially available clinical systems. We show that this performance permits genuinely real-time measurement of a patient, live during both setup and radiation treatment delivery. It is also fast enough to provide smooth dynamic visualizations of motion at all points on the wrap-around body surface for radiotherapy staff and intuitive, direct feed-back to patients.

  12. Compact remote optical system for real time measurement of aerosol emissions

    NASA Astrophysics Data System (ADS)

    Waldherr, Gregor A.; Wylie, Michael T. V.; Lin, Hai

    2014-05-01

    Demonstrating particle matter (PM) emissions compliance with environmental regulations is required for operation of any industrial, commercial or military facility. Emission sources are initially screened based on their visible opacity via US EPA Method 9 standard. Nowadays, it is rather surprising that opacity is still visually determined by human eyes with smoke school training and semi-annual certification. Nonetheless, opacity alone doesn't reveal particle concentration and size distribution which is crucial to determine PM values. It would be desirable to have an automated, calibratable device to make such a measurement with higher accuracy and reliability and is not available to date. We present our preliminary work on developing a compact, hand portable system capable of quantitatively determining plume optical opacity in combination with possible particle concentration and size distribution (and hence PM) measurement for standoff distances up to 150 meters. Our benchtop lidar-based system was built with a frequencydoubled Q-switched Nd:YAG laser and an optical receiver. We have demonstrated the feasibility of a remote-capable optical sensor system for real-time continuous monitoring of visible emission plumes and its effectiveness for quantitative opacity measurement. The hand-portable Remote Plume Particulate Matter (RPPM) meter being developed will be capable of determining opacity and PM load from remote PM sources will provide a regulatory compliance solution for visible emissions from sources for environmental studies, industrial and military applications.

  13. A cavity ring-down spectroscopy sensor for real-time Hall thruster erosion measurements

    SciTech Connect

    Lee, B. C.; Huang, W.; Tao, L.; Yamamoto, N.; Yalin, A. P.; Gallimore, A. D.

    2014-05-15

    A continuous-wave cavity ring-down spectroscopy sensor for real-time measurements of sputtered boron from Hall thrusters has been developed. The sensor uses a continuous-wave frequency-quadrupled diode laser at 250 nm to probe ground state atomic boron sputtered from the boron nitride insulating channel. Validation results from a controlled setup using an ion beam and target showed good agreement with a simple finite-element model. Application of the sensor for measurements of two Hall thrusters, the H6 and SPT-70, is described. The H6 was tested at power levels ranging from 1.5 to 10 kW. Peak boron densities of 10 ± 2 × 10{sup 14} m{sup −3} were measured in the thruster plume, and the estimated eroded channel volume agreed within a factor of 2 of profilometry. The SPT-70 was tested at 600 and 660 W, yielding peak boron densities of 7.2 ± 1.1 × 10{sup 14} m{sup −3}, and the estimated erosion rate agreed within ∼20% of profilometry. Technical challenges associated with operating a high-finesse cavity in the presence of energetic plasma are also discussed.

  14. Wearable Biomedical Measurement Systems for Assessment of Mental Stress of Combatants in Real Time

    PubMed Central

    Seoane, Fernando; Mohino-Herranz, Inmaculada; Ferreira, Javier; Alvarez, Lorena; Buendia, Ruben; Ayllón, David; Llerena, Cosme; Gil-Pita, Roberto

    2014-01-01

    The Spanish Ministry of Defense, through its Future Combatant program, has sought to develop technology aids with the aim of extending combatants' operational capabilities. Within this framework the ATREC project funded by the “Coincidente” program aims at analyzing diverse biometrics to assess by real time monitoring the stress levels of combatants. This project combines multidisciplinary disciplines and fields, including wearable instrumentation, textile technology, signal processing, pattern recognition and psychological analysis of the obtained information. In this work the ATREC project is described, including the different execution phases, the wearable biomedical measurement systems, the experimental setup, the biomedical signal analysis and speech processing performed. The preliminary results obtained from the data analysis collected during the first phase of the project are presented, indicating the good classification performance exhibited when using features obtained from electrocardiographic recordings and electrical bioimpedance measurements from the thorax. These results suggest that cardiac and respiration activity offer better biomarkers for assessment of stress than speech, galvanic skin response or skin temperature when recorded with wearable biomedical measurement systems. PMID:24759113

  15. Wearable biomedical measurement systems for assessment of mental stress of combatants in real time.

    PubMed

    Seoane, Fernando; Mohino-Herranz, Inmaculada; Ferreira, Javier; Alvarez, Lorena; Buendia, Ruben; Ayllón, David; Llerena, Cosme; Gil-Pita, Roberto

    2014-04-22

    The Spanish Ministry of Defense, through its Future Combatant program, has sought to develop technology aids with the aim of extending combatants' operational capabilities. Within this framework the ATREC project funded by the "Coincidente" program aims at analyzing diverse biometrics to assess by real time monitoring the stress levels of combatants. This project combines multidisciplinary disciplines and fields, including wearable instrumentation, textile technology, signal processing, pattern recognition and psychological analysis of the obtained information. In this work the ATREC project is described, including the different execution phases, the wearable biomedical measurement systems, the experimental setup, the biomedical signal analysis and speech processing performed. The preliminary results obtained from the data analysis collected during the first phase of the project are presented, indicating the good classification performance exhibited when using features obtained from electrocardiographic recordings and electrical bioimpedance measurements from the thorax. These results suggest that cardiac and respiration activity offer better biomarkers for assessment of stress than speech, galvanic skin response or skin temperature when recorded with wearable biomedical measurement systems.

  16. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  17. Real-time Seismic Amplitude Measurement (RSAM): a volcano monitoring and prediction tool

    USGS Publications Warehouse

    Endo, E.T.; Murray, T.

    1991-01-01

    Seismicity is one of the most commonly monitored phenomena used to determine the state of a volcano and for the prediction of volcanic eruptions. Although several real-time earthquake-detection and data acquisition systems exist, few continuously measure seismic amplitude in circumstances where individual events are difficult to recognize or where volcanic tremor is prevalent. Analog seismic records provide a quick visual overview of activity; however, continuous rapid quantitative analysis to define the intensity of seismic activity for the purpose of predicing volcanic eruptions is not always possible because of clipping that results from the limited dynamic range of analog recorders. At the Cascades Volcano Observatory, an inexpensive 8-bit analog-to-digital system controlled by a laptop computer is used to provide 1-min average-amplitude information from eight telemetered seismic stations. The absolute voltage level for each station is digitized, averaged, and appended in near real-time to a data file on a multiuser computer system. Raw realtime seismic amplitude measurement (RSAM) data or transformed RSAM data are then plotted on a common time base with other available volcano-monitoring information such as tilt. Changes in earthquake activity associated with dome-building episodes, weather, and instrumental difficulties are recognized as distinct patterns in the RSAM data set. RSAM data for domebuilding episodes gradually develop into exponential increases that terminate just before the time of magma extrusion. Mount St. Helens crater earthquakes show up as isolated spikes on amplitude plots for crater seismic stations but seldom for more distant stations. Weather-related noise shows up as low-level, long-term disturbances on all seismic stations, regardless of distance from the volcano. Implemented in mid-1985, the RSAM system has proved valuable in providing up-to-date information on seismic activity for three Mount St. Helens eruptive episodes from 1985 to

  18. Real-time frequency-domain fiber optic sensor for intra-arterial blood oxygen measurements

    NASA Astrophysics Data System (ADS)

    Alcala, J. R.; Scott, Ian L.; Parker, Jennifer W.; Atwater, Beauford W.; Yu, Clement; Fischer, Russell; Bellingrath, K.

    1993-05-01

    A real time frequency domain phosphorimeter capable of measuring precise and accurate excited state lifetimes for determining oxygen is described. This frequency domain instrument does not make use of cross correlation techniques traditionally used in frequency domain fluorometers. Instead, the electrical signal from the detector is filtered to contain only the first several harmonics. This filtered signal is then sampled and averaged over a few thousand cycles. The absolute phase and absolute modulation of each sampled harmonic of the excitation and of the luminescence is computed by employing fast Fourier transform algorithms. The phase delay and the modulation ratio is then calculated at each harmonic frequency. A least squares fit is performed in the frequency domain to obtain the lifetimes of discrete exponentials. Oxygen concentrations are computed from these lifetimes. Prototypes based on these techniques were built employing commercially available components. Results from measurements in saline solution and in the arterial blood of dogs show that oxygen concentrations can be determined reproducibly. The system drift is less than 1% in over 100 hours of continuous operation. The performance of fiber optic sensors was evaluated in dogs over a period of 10 hours. The sensors tracked changes in arterial oxygen tension over the course of the experiment without instabilities. The overall response of the system was about 90 seconds. The update time was 3 seconds.

  19. Real-time measurement of sodium chloride in individual aerosol particles by mass spectrometry

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Friedlander, S. K.

    1985-01-01

    The method of particle analysis by mass spectrometry has been applied to the quantitative measurement of sodium chloride in individual particles on a real-time basis. Particles of known masses are individually introduced, in the form of a beam, into a miniature Knudsen cell oven (1600 K). The oven is fabricated from rhenium metal sheet (0.018 mm thick) and is situated in the ion source of a quadrupole mass spectrometer. A particle once inside the oven is trapped and completely volatilized; this overcomes the problem of partial volatilization due to particles bouncing from the filament surface. Individual particles are thermally volatilized and ionized inside the rhenium oven, and produce discrete sodium ion pulses whose intensities are measured with the quadrupole mass spectrometer. An ion pulse width of several milliseconds (4-12 ms) is found for particles in the mass range 1.3 x 10 to the -13th to 5.4 x 10 to the -11th g. The sodium ion intensity is found to be proportional to the particle mass to the 0.86-power. The intensity distribution for monodisperse aerosol particles possesses a geometric standard deviation of 1.09, showing that the method can be used for the determination of the mass distribution function with good resolution in a polydisperse aerosol.

  20. In-Situ Real Time Measurements of Molten Glass Properties, Final Report

    SciTech Connect

    Robert De Saro; Joe Craparo

    2007-12-16

    Energy Research Company (ERCo) of Staten Island, NY has developed a sensor capable of measuring in situ and in real time, both the elemental composition and the temperature of molten glass. A prototype sensor has been designed, constructed and tested in ERCo's laboratory. The sensor was used to collect atomic emission spectra from molten fiberglass via Laser Induced Breakdown Spectroscopy (LIBS). From these spectra, we were able to readily identify all elements of interest (B, Si, Ca, Fe, Mg, Na, Sr, Al). The high signal-to-background signals achieved suggest that data from the sensor can be used to determine elemental concentrations, either through calibration curves or using ERCo's calibrationless method. ERCo's technology fits in well with DOE's Glass Industry Technology Roadmap which emphasizes the need for accurate process and feedstock sensors. Listed first under technological barriers to increased production efficiency is the 'Inability to accurately measure and control the production process'. A large-scale glass melting furnace, developed by SenCer Inc. of Penn Yan, NY was installed in ERCo's laboratory to ensure that a large enough quantity of glass could be melted and held at temperature in the presence of the water-cooled laser sensor without solidifying the glass.

  1. Enzymatic cycling method using creatine kinase to measure creatine by real-time detection.

    PubMed

    Ueda, Shigeru; Sakasegawa, Shin-Ichi

    2016-08-01

    We have developed a novel enzymatic cycling method that uses creatine kinase (CK) to measure creatine. The method takes advantage of the reversibility of the CK reaction in which the forward (creatine phosphate forming) and reverse reactions are catalyzed in the presence of an excess amount of ATP and IDP, respectively. Real-time detection was accomplished using ADP-dependent glucokinase (ADP-GK) together with glucose-6-phosphate dehydrogenase. ADP, one of the cycling reaction products, was distinguished from IDP by using the nucleotide selectivity of the ADP-GK. The increasing level of ADP was measured from the level of reduced NADP at 340 nm. The method is appropriate for an assay that requires high sensitivity because the rate of increase in absorbance at 340 nm is proportional to the amount of CK present in the reaction mix. We reasoned that the method with CK in combination with creatinine amidohydrolase could be used to assay creatinine, an important marker of kidney function. Our results confirmed the quantitative capability of the assay. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Real-Time Measurements of a Tsunami Wave Height on DART Records

    NASA Astrophysics Data System (ADS)

    Tolkova, E.

    2009-05-01

    In 2005-2008, an array of tsunameters (Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys) was deployed in the oceans. The real-time measurements of an instant sea surface height with 1 mm accuracy, provided by the buoys, are used to detect and measure a tsunami wave, to deduce some of its characteristics (such as to specify the tsunami source) and eventually to evaluate the tsunami hazard at the coast in advance of the tsunami arrival. The accuracy of detecting tsunami waves at DART buoys largely determines the accuracy of any forecast of the future tsunami evolution. However, a tsunami component of a DART buoy signal is commonly under few cm in amplitude, and is masked by much more powerful tidal component with typical amplitudes of one meter or more. Tidal predictions and digital filtering are the two major techniques of removing a tidal component of a record. Tidal predictions require a priori knowledge about tidal processes at a particular buoy location, and, in the best case, are 2-4 cm accurate, which is not accurate enough for tsunami quantification. Extracting the tsunami in real-time via conventional digital filtering (such as convolution with a sliding window) also faces some difficulties. First, an ongoing tsunami signal is located on the edge of the record. Second, a record might have missing data. In particular, as a buoy construction feature, "an event" recording is likely to start with a few hour long gap. A filtering technique robust to "edge effects" and gaps in data has been developed in NOAA Center for Tsunami Research for de-tiding DART records in real-time (Tolkova E. Principal Component Analysis of Tsunami Buoy Record: Tide Prediction and Removal. Dyn. Atmos. Oceans, Vol.46/1-4, pp.62-82 (2009)). The method employs a pre-computed orthogonal set of functions defined on a specific time interval. It has been shown, experimentally and analytically, that a sub-space spanned by these functions holds any tidal fragment of a specific length

  3. Multi-Fluorescence Real-Time PCR Assay for Detection of RIF and INH Resistance of M. tuberculosis

    PubMed Central

    Peng, Jingfu; Yu, Xiaoli; Cui, Zhenling; Xue, Wenfei; Luo, Ziyi; Wen, Zilu; Liu, Minghua; Jiang, Danqing; Zheng, Heping; Wu, Hai; Zhang, Shulin; Li, Yao

    2016-01-01

    Background: Failure to early detect multidrug-resistant tuberculosis (MDR-TB) results in treatment failure and poor clinical outcomes, and highlights the need to rapidly detect resistance to rifampicin (RIF) and isoniazid (INH). Methods: In Multi-Fluorescence quantitative Real-Time PCR (MF-qRT-PCR) assay, 10 probes labeled with four kinds of fluorophores were designed to detect the mutations in regions of rpoB, katG, mabA-inhA, oxyR-ahpC, and rrs. The efficiency of MF-qRT-PCR assay was tested using 261 bacterial isolates and 33 clinical sputum specimens. Among these samples, 227 Mycobacterium tuberculosis isolates were analyzed using drug susceptibility testing (DST), DNA sequencing and MF-qRT-PCR assay. Results: Compared with DST, MF-qRT-PCR sensitivity and specificity for RIF-resistance were 94.6 and 100%, respectively. And the detection sensitivity and specificity for INH-resistance were 85.9 and 95.3%, respectively. Compared with DNA sequencing, the sensitivity and specificity of our assay were 97.2 and 100% for RIF-resistance and 97.9 and 96.4% for INH-resistance. Compared with Phenotypic strain identification, MF-qRT-PCR can distinguish 227 M. tuberculosis complexes (MTC) from 34 Non-tuberculous mycobacteria (NTM) isolates with 100% accuracy rate. Conclusions: MF-qRT-PCR assay was an efficient, accurate, reliable, and easy-operated method for detection of RIF and INH-resistance, and distinction of MTC and NTM of clinical isolates. PMID:27199947

  4. A dual inhibitor against prolyl isomerase Pin1 and cyclophilin discovered by a novel real-time fluorescence detection method

    SciTech Connect

    Mori, Tadashi; Hidaka, Masafumi; Lin, Yi-Chin; Yoshizawa, Ibuki; Okabe, Takayoshi; Egashira, Shinichiro; Kojima, Hirotatsu; Nagano, Tetsuo; Koketsu, Mamoru; Takamiya, Mari; Uchida, Takafumi

    2011-03-18

    Research highlights: {yields} A Pin1 (prolyl isomerase) inhibitor, TME-001, has been discovered by using a new established high-throughput screening method. {yields} The TME-001 showed a cell-active inhibition with lower cytotoxic effect than known Pin1 inhibitors. {yields} Kinetic analyses revealed that the TME-001 is the first compound that exhibits dual inhibition of Pin1 and another type of prolyl isomerase, cyclophilin. {yields} Thus, similarities of structure and reaction mechanism between Pin1 and cyclophilin are proposed. -- Abstract: Pin1, a peptidyl prolyl cis/trans isomerase (PPIase), is a potential target molecule for cancer, infectious disease, and Alzheimer's disease. We established a high-throughput screening method for Pin1 inhibitors, which employs a real-time fluorescence detector. This screening method identified 66 compounds that inhibit Pin1 out of 9756 compounds from structurally diverse chemical libraries. Further evaluations of surface plasmon resonance methods and a cell proliferation assay were performed. We discovered a cell-active inhibitor, TME-001 (2-(3-chloro-4-fluoro-phenyl)-isothiazol-3-one). Surprisingly, kinetic analyses revealed that TME-001 is the first compound that exhibits dual inhibition of Pin1 (IC{sub 50} = 6.1 {mu}M) and cyclophilin, another type of PPIase, (IC{sub 50} = 13.7 {mu}M). This compound does not inhibit FKBP. This finding suggests the existence of similarities of structure and reaction mechanism between Pin1 and cyclophilin, and may lead to a more complete understanding of the active sites of PPIases.

  5. Assimilation of real-time riometer measurements into models of 30 MHz polar cap absorption

    NASA Astrophysics Data System (ADS)

    Rogers, Neil Christopher; Honary, Farideh

    2015-04-01

    Space weather events may adversely affect high frequency (HF) radio propagation, hence the ability to provide nowcasting and forecasting of HF radio absorption is key for industries that rely on HF communications. This paper presents methods of assimilating 30 MHz radio absorption measurements into two types of ionospheric polar cap absorption (PCA) model to improve their performance as nowcasting tools. Type 1 models calculate absorption as m times the square root of the flux of solar protons above an energy threshold, Et. Measurements from 14 riometers during 94 solar proton events (1995-2010) are assimilated by optimising the day and night values of m by linear regression. Further non-linear optimisations are demonstrated in which parameters such as Et are also optimised and additional terms characterise local time and seasonal variations. These optimisations reduce RMS errors by up to 36%. Type 2 models incorporate altitude profiles of electron and neutral densities and electron temperatures. Here the scale height of the effective recombination coefficient profile in the D-region is optimised by regression. Furthermore, two published models of the rigidity cut-off latitude (CL) are assessed by comparison with riometer measurements. A small improvement in performance is observed by introducing a 3-h lag in the geomagnetic index Kp in the CL models. Assimilating data from a single riometer in the polar cap reduces RMS errors below 1 dB with less than 0.2 dB bias. However, many high-latitude riometers now provide absorption measurements in near-real time and we demonstrate how these data may be assimilated by fitting a low-order spherical harmonic function to both the measurements and a PCA model with optimised parameters.

  6. DEVELOPMENT OF AN ON-LINE, REAL-TIME ALPHA RADIATION MEASURING INSTRUMENT FOR LIQUID STREAMS

    SciTech Connect

    1996-11-22

    The Department of Energy (DOE) has expressed a need for an on-line, real-time instrument for assaying alpha-emitting radionuclides (uranium and the transuranics) in effluent waters leaving DOE sites to ensure compliance with regulatory limits. Due to the short range of alpha particles in water ({approximately}40 Tm), it is necessary now to intermittently collect samples of water and send them to a central laboratory for analysis. A lengthy and costly procedure is used to separate and measure the radionuclides from each sample. Large variations in radionuclide concentrations in the water may go undetected due to the sporadic sampling. Even when detected, the reading may not be representative of the actual stream concentration. To address these issues, Tecogen, a division of Thermo Power Corporation, a Thermo Electron company, is developing a real-time, field-deployable, alpha monitor based on a solid-state silicon wafer semiconductor (patent pending, to be assigned to the Department of Energy). The Thermo Alpha Monitor (TAM) will serve to monitor effluent water streams (Subsurface Contaminants Focus Area) and will be suitable for process control of remediation as well as decontamination and decommissioning operations, such as monitoring scrubber or rinse water radioactivity levels (Mixed Waste Focus Area and D&D Focus Area). It would be applicable for assaying other liquids, such as oil, or solids after proper preconditioning. Rapid isotopic alpha air monitoring is also possible using this technology. This instrument for direct counting of alpha-emitters in aqueous streams is presently being developed by Thermo Power under a development program funded by the DOE Environmental Management program (DOE-EM), administered by the Morgantown Energy Technology Center (METC). Under this contract, Thermo Power has demonstrated a solid-state, silicon-based semiconductor instrument, which uses a proprietary film-based collection system to quantitatively extract the

  7. Environmental Measurement While Drilling System for Real-Time Field Screening of Contaminants

    SciTech Connect

    Lockwood, G.J.; Normann, R.A.; Williams, C.V.

    1999-02-22

    Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of subsurface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. Real-time information on environmental conditions, drill bit location and temperature during drilling is valuable in many environmental restoration operations. This type of information can be used to provide field screening data and improved efficiency of site characterization activities. The Environmental Measurement-While-Drilling (EMWD) System represents an innovative blending of new and existing technology in order to obtain real-time data during drilling. The system consists of two subsystems. The down-hole subsystem (at the drill bit) consists of sensors, a power supply, a signal conditioning and transmitter board, and a radio-frequency (RF) coaxial cable. The up-hole subsystem consists of a battery pack/coil, pickup coil, receiver, and personal computer. The system is compatible with fluid miser drill pipe, a directional drilling technique that uses minimal drilling fluids and generates little to no secondary waste. In EMWD, downhole sensors are located behind the drill bit and linked by a high-speed data transmission system to a computer at the surface. Sandia-developed Windows{trademark}-based software is used for data display and storage. As drilling is conducted, data is collected on the nature and extent of contamination, enabling on-the-spot decisions regarding drilling and sampling strategies. Initially, the downhole sensor consisted of a simple gamma radiation detector, a Geiger-Mueller tube (GMT). The design includes data assurance techniques to increase safety by reducing the probability of giving a safe indication when an unsafe condition exists. The EMWD system has been improved by the integration of a Gamma Ray Spectrometer (GRS) in place of the GMT. The GRS consists of a sodium iodide

  8. Kinetics and thermodynamics of sucrose hydrolysis from real-time enthalpy and heat capacity measurements.

    PubMed

    Tombari, E; Salvetti, G; Ferrari, C; Johari, G P

    2007-01-25

    We report a real time study of the enthalpy release and heat capacity during the course of HCl-catalyzed hydrolysis of sucrose to fructose and glucose. Measurements were performed during both isothermal conditions and during slow heating and then cooling at a controlled rate. The reaction rate constant of the first-order kinetics follows an Arrhenius relation with activation energy of 109.2 kJ/mol of sucrose. On hydrolysis, the enthalpy decreases by 14.4 kJ/mol of sucrose at 310 K, and the heat capacity, Cp, increases by 61 J mol-1 K-1 of sucrose in the solution. The enthalpy of hydrolysis decreases with increase in the temperature and DeltaCp on hydrolysis increases. The effects are attributed to change in the configurational and vibrational partition functions as one covalent bond in sucrose breaks to form two molecules, which then individually form additional hydrogen bonds and alter the water's structure in the solution. Cp of the solution increases with temperature less rapidly before sucrose hydrolysis than after it. This may reflect an increase in the configurational contribution to Cp as the hydrogen bond population changes.

  9. KERMA-based radiation dose management system for real-time patient dose measurement

    NASA Astrophysics Data System (ADS)

    Kim, Kyo-Tae; Heo, Ye-Ji; Oh, Kyung-Min; Nam, Sang-Hee; Kang, Sang-Sik; Park, Ji-Koon; Song, Yong-Keun; Park, Sung-Kwang

    2016-07-01

    Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient's radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient's radiation exposure and acquisition of diagnostic images.

  10. Measuring respiratory activity of adipocytes and adipose tissues in real time.

    PubMed

    Bugge, Anne; Dib, Lea; Collins, Sheila

    2014-01-01

    The realization that obesity and its associated diseases have become one of modern society's major challenges to the health of the world's population has fueled much effort to understand white adipocyte biology and elucidate pathways to increase energy expenditure. One strategy has been to increase the oxidative capacity and activity of the adipocytes themselves. This has the advantage that free fatty acids (FAs) would not be released into the circulation in copious amounts, which can have detrimental effects. This is particularly true for obese individuals, who often already display severe dyslipidemia, putting them at increased risk for cardiovascular diseases. It was recently discovered that adult humans, in addition to infants, possess active brown adipocytes, characterized by expression of the mitochondrial electron gradient dissipater uncoupling protein 1 (UCP1). This has generated renewed interest in finding ways to "convert" or "adapt" white adipocytes into a more brown adipocyte-like state by increasing mitochondrial content and expression of UCP1 and activating UCP1 via lipolysis-mediated free FAs. Another approach to consider is elevating the activity of the not insignificant amount of mitochondria found in white adipocytes. The invention of the XF Flux Analyzer by Seahorse Bioscience has revolutionized this line of research as it allows for real-time measurements of respiration in multiple samples simultaneously. In this chapter, we describe our approaches and experience with employing this technology to study the metabolism of mouse and human primary and immortalized cells and mouse white adipose tissue. © 2014 Elsevier Inc. All rights reserved.

  11. Real-time measurement of volatile chemicals released by bed bugs during mating activities.

    PubMed

    Kilpinen, Ole; Liu, Dezhao; Adamsen, Anders Peter S

    2012-01-01

    In recent years, bed bug (Hemiptera: Cimicidae) problems have increased dramatically in many parts of the world, leading to a renewed interest in their chemical ecology. Most studies of bed bug semiochemicals have been based on the collection of volatiles over a period of time followed by chemical analysis. Here we present for the first time, a combination of proton transfer reaction mass spectrometry and video analysis for real-time measurement of semiochemicals emitted by isolated groups of bed bugs during specific behavioural activities. The most distinct peaks in the proton transfer reaction mass spectrometry recordings were always observed close to the termination of mating attempts, corresponding to the defensive emissions that bed bugs have been suspected to exploit for prevention of unwanted copulations. The main components of these emissions were (E)-2-hexenal and (E)-2-octenal recorded in ratios between 1:3 and 3:1. In the current study, the quantity varied over 1000 fold for both of the compounds with up to 40 µg total release in a single emission. Males also emit defensive compounds due to homosexual copulation attempts by other males, and no significant differences were observed in the ratio or the amount of the two components released from males or females. In summary, this study has demonstrated that combining proton-transfer-reaction mass spectrometry with video analysis can provide detailed information about semiochemicals emitted during specific behavioural activities.

  12. Pseudomonas stutzeri Nitrite Reductase Gene Abundance in Environmental Samples Measured by Real-Time PCR

    PubMed Central

    Grüntzig, Verónica; Nold, Stephen C.; Zhou, Jizhong; Tiedje, James M.

    2001-01-01

    We used real-time PCR to quantify the denitrifying nitrite reductase gene (nirS), a functional gene of biogeochemical significance. The assay was tested in vitro and applied to environmental samples. The primer-probe set selected was specific for nirS sequences that corresponded approximately to the Pseudomonas stutzeri species. The assay was linear from 1 to 106 gene copies (r2 = 0.999). Variability at low gene concentrations did not allow detection of twofold differences in gene copy number at less than 100 copies. DNA spiking and cell-addition experiments gave predicted results, suggesting that this assay provides an accurate measure of P. stutzeri nirS abundance in environmental samples. Although P. stutzeri abundance was high in lake sediment and groundwater samples, we detected low or no abundance of this species in marine sediment samples from Puget Sound (Wash.) and from the Washington ocean margin. These results suggest that P. stutzeri may not be a dominant marine denitrifier. PMID:11157241

  13. Engineering genetically encoded nanosensors for real-time in vivo measurements of citrate concentrations.

    PubMed

    Ewald, Jennifer C; Reich, Sabrina; Baumann, Stephan; Frommer, Wolf B; Zamboni, Nicola

    2011-01-01

    Citrate is an intermediate in catabolic as well as biosynthetic pathways and is an important regulatory molecule in the control of glycolysis and lipid metabolism. Mass spectrometric and NMR based metabolomics allow measuring citrate concentrations, but only with limited spatial and temporal resolution. Methods are so far lacking to monitor citrate levels in real-time in-vivo. Here, we present a series of genetically encoded citrate sensors based on Förster resonance energy transfer (FRET). We screened databases for citrate-binding proteins and tested three candidates in vitro. The citrate binding domain of the Klebsiella pneumoniae histidine sensor kinase CitA, inserted between the FRET pair Venus/CFP, yielded a sensor highly specific for citrate. We optimized the peptide linkers to achieve maximal FRET change upon citrate binding. By modifying residues in the citrate binding pocket, we were able to construct seven sensors with different affinities spanning a concentration range of three orders of magnitude without losing specificity. In a first in vivo application we show that E. coli maintains the capacity to take up glucose or acetate within seconds even after long-term starvation.

  14. Real-Time Measurement of Volatile Chemicals Released by Bed Bugs during Mating Activities

    PubMed Central

    Kilpinen, Ole; Liu, Dezhao; Adamsen, Anders Peter S.

    2012-01-01

    In recent years, bed bug (Hemiptera: Cimicidae) problems have increased dramatically in many parts of the world, leading to a renewed interest in their chemical ecology. Most studies of bed bug semiochemicals have been based on the collection of volatiles over a period of time followed by chemical analysis. Here we present for the first time, a combination of proton transfer reaction mass spectrometry and video analysis for real-time measurement of semiochemicals emitted by isolated groups of bed bugs during specific behavioural activities. The most distinct peaks in the proton transfer reaction mass spectrometry recordings were always observed close to the termination of mating attempts, corresponding to the defensive emissions that bed bugs have been suspected to exploit for prevention of unwanted copulations. The main components of these emissions were (E)-2-hexenal and (E)-2-octenal recorded in ratios between 1∶3 and 3∶1. In the current study, the quantity varied over 1000 fold for both of the compounds with up to 40 µg total release in a single emission. Males also emit defensive compounds due to homosexual copulation attempts by other males, and no significant differences were observed in the ratio or the amount of the two components released from males or females. In summary, this study has demonstrated that combining proton-transfer-reaction mass spectrometry with video analysis can provide detailed information about semiochemicals emitted during specific behavioural activities. PMID:23227225

  15. Real-time measurement of glucose using chrono-impedance technique on a second generation biosensor.

    PubMed

    Mayorga Martinez, Carmen C; Treo, Ernesto F; Madrid, Rossana E; Felice, Carmelo C

    2011-11-15

    Chrono-impedance technique (CIT) was implemented as a new transduction method for real time measurement of glucose in a biosensor system based in carbon paste (CP)/Ferrocene (FC)/glucose oxidase (GOx). The system presents high selectivity because the optimal stimulation signal composed by a 165mV DC potential and 50mV(RMS) AC signal at 0.4Hz was used. The low DC potential used decreased the interfering species effect and the biosensor showed a linear impedance response toward glucose detection at concentrations from 0mM to 20mM,with 0.9853 and 0.9945 correlation coefficient for impedance module (|Z|) and phase (Φ), respectively. The results of quadruplicate sets reveal the high repeatability and reproducibility of the measurements with a relative standard deviation (RSD) less than 10%. CIT presented good accuracy (within 10% of the actual value) and precision did not exceed 15% of RSD for high concentration values and 20% for the low concentration ones. In addition, a high correlation coefficient (R(2)=0.9954) between chrono-impedance and colorimetric methods was obtained. On the other hand, when two samples prepared at the same conditions were measured in parallel with both methods (the measurement was repeated four times), it should be noticed that student's t-test produced no difference between the two mentioned methods (p=1). The biosensor system hereby presented is highly specific to glucose detection and shows a better linear range than the one reported on the previous article. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Measuring real-time streamflow using emerging technologies: Radar, hydroacoustics, and the probability concept

    USGS Publications Warehouse

    Fulton, J.; Ostrowski, J.

    2008-01-01

    Forecasting streamflow during extreme hydrologic events such as floods can be problematic. This is particularly true when flow is unsteady, and river forecasts rely on models that require uniform-flow rating curves to route water from one forecast point to another. As a result, alternative methods for measuring streamflow are needed to properly route flood waves and account for inertial and pressure forces in natural channels dominated by nonuniform-flow conditions such as mild water surface slopes, backwater, tributary inflows, and reservoir operations. The objective of the demonstration was to use emerging technologies to measure instantaneous streamflow in open channels at two existing US Geological Survey streamflow-gaging stations in Pennsylvania. Surface-water and instream-point velocities were measured using hand-held radar and hydroacoustics. Streamflow was computed using the probability concept, which requires velocity data from a single vertical containing the maximum instream velocity. The percent difference in streamflow at the Susquehanna River at Bloomsburg, PA ranged from 0% to 8% with an average difference of 4% and standard deviation of 8.81 m3/s. The percent difference in streamflow at Chartiers Creek at Carnegie, PA ranged from 0% to 11% with an average difference of 5% and standard deviation of 0.28 m3/s. New generation equipment is being tested and developed to advance the use of radar-derived surface-water velocity and instantaneous streamflow to facilitate the collection and transmission of real-time streamflow that can be used to parameterize hydraulic routing models.

  17. Wavelength-dependent backscattering measurements for quantitative real-time monitoring of apoptosis in living cells

    NASA Astrophysics Data System (ADS)

    Mulvey, Christine S.; Sherwood, Carly A.; Bigio, Irving J.

    2009-11-01

    Apoptosis-programmed cell death-is a cellular process exhibiting distinct biochemical and morphological changes. An understanding of the early morphological changes that a cell undergoes during apoptosis can provide the opportunity to monitor apoptosis in tissue, yielding diagnostic and prognostic information. There is avid interest regarding the involvement of apoptosis in cancer. The initial response of a tumor to successful cancer treatment is often massive apoptosis. Current apoptosis detection methods require cell culture disruption. Our aim is to develop a nondisruptive optical method to monitor apoptosis in living cells and tissues. This would allow for real-time evaluation of apoptotic progression of the same cell culture over time without alteration. Elastic scattering spectroscopy (ESS) is used to monitor changes in light-scattering properties of cells in vitro due to apoptotic morphology changes. We develop a simple instrument capable of wavelength-resolved ESS measurements from cell cultures in the backward direction. Using Mie theory, we also develop an algorithm that extracts the size distribution of scatterers in the sample. The instrument and algorithm are validated with microsphere suspensions. For cell studies, Chinese hamster ovary (CHO) cells are cultured to confluence on plates and are rendered apoptotic with staurosporine. Backscattering measurements are performed on pairs of treated and control samples at a sequence of times up to 6-h post-treatment. Initial results indicate that ESS is capable of discriminating between treated and control samples as early as 10- to 15-min post-treatment, much earlier than is sensed by standard assays for apoptosis. Extracted size distributions from treated and control samples show a decrease in Rayleigh and 150-nm scatterers, relative to control samples, with a corresponding increase in 200-nm particles. Work continues to correlate these size distributions with underlying morphology. To our knowledge, this

  18. A bio-inspired real-time capable artificial lateral line system for freestream flow measurements.

    PubMed

    Abels, C; Qualtieri, A; De Vittorio, M; Megill, W M; Rizzi, F

    2016-06-03

    To enhance today's artificial flow sensing capabilities in aerial and underwater robotics, future robots could be equipped with a large number of miniaturized sensors distributed over the surface to provide high resolution measurement of the surrounding fluid flow. In this work we show a linear array of closely separated bio-inspired micro-electro-mechanical flow sensors whose sensing mechanism is based on a piezoresistive strain-gauge along a stress-driven cantilever beam, mimicking the biological superficial neuromasts found in the lateral line organ of fishes. Aiming to improve state-of-the-art flow sensing capability in autonomously flying and swimming robots, our artificial lateral line system was designed and developed to feature multi-parameter freestream flow measurements which provide information about (1) local flow velocities as measured by the signal amplitudes from the individual cantilevers as well as (2) propagation velocity, (3) linear forward/backward direction along the cantilever beam orientation and (4) periodicity of pulses or pulse trains determined by cross-correlating sensor signals. A real-time capable cross-correlation procedure was developed which makes it possible to extract freestream flow direction and velocity information from flow fluctuations. The computed flow velocities deviate from a commercial system by 0.09 m s(-1) at 0.5 m s(-1) and 0.15 m s(-1) at 1.0 m s(-1) flow velocity for a sampling rate of 240 Hz and a sensor distance of 38 mm. Although experiments were performed in air, the presented flow sensing system can be applied to underwater vehicles as well, once the sensors are embedded in a waterproof micro-electro-mechanical systems package.

  19. First measurement of pp neutrinos in real time in the Borexino detector

    NASA Astrophysics Data System (ADS)

    Mosteiro, Pablo

    2014-09-01

    The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. Neutrinos (nu) produced by these nuclear reactions exit the Sun and reach Earth within minutes, providing us with key information about what goes on at the core of our star. For over twenty years since the first detection of solar neutrinos in the late 1960's, an apparent deficit in their detection rate was known as the Solar Neutrino Problem. Today, the Mikheyev-Smirnov-Wolfenstein (MSW) effect is the accepted mechanism by which neutrinos oscillate inside the Sun, arriving at Earth as a mixture of nue, numu and nutau, the latter two of which were invisible to early detectors. Several experiments have now confirmed the observation of neutrino oscillations. These experiments, when their results are combined together, have demonstrated that neutrino oscillations are well described by the Large Mixing Angle (LMA) solution of the MSW effect. This thesis presents the first measurement of pp neutrinos in the Borexino detector, which is another validation of the LMA-MSW model of neutrino oscillations. In addition, it is one more step towards the completion of the spectroscopy of pp chain neutrinos in Borexino, leaving only the extremely faint hep neutrinos undetected. This advance validates the experiment itself and its previous results. This is, furthermore, the first direct real-time measurement of pp neutrinos. We find a pp neutrino detection rate of 143+/-16 (stat)+/-10 (syst) cpd/100 t in the Borexino experiment, which translates, according to the LMA-MSW model, to (6.42+/-0.85)x1010 cm -2 s-1. We also report on a measurement of neutrons in a dedicated system within the Borexino detector, which resulted in an improved understanding of neutron rates in liquid scintillator detectors at Gran Sasso depths. This result is crucial to the development of novel direct dark matter detection experiments.

  20. Real time Measurement of Metabolic States in Living Cells using Genetically-encoded NADH Sensors

    PubMed Central

    Zhao, Yuzheng; Yang, Yi; Loscalzo, Joseph

    2014-01-01

    Redox metabolism plays critical roles in multiple biological processes and diseases. Until recently, knowledge of specific, key redox processes in living systems was limited by the lack of adequate methodology. Reduced nicotinamide adenine dinucleotide (NADH) and its oxidized form (NAD+) is the most important small molecule in the redox metabolism of mammalian cells. We previously reported a series of genetically encoded fluorescent sensors for intracellular NADH detection. Here, we present an accounting of experimental components and considerations, such as protein expression and purification, fluorescence titration, transfections, and confocal imaging, necessary to perform a standardized NADH assay experiment with these probes. In addition, we outline initial experiments used to derive basic principles of NADH/NAD+ redox biology in vitro. Finally, we describe a protocol for a steady-state kinetics experiment, and the processing of experimental data to measure intracellular NADH levels. PMID:24862275

  1. CLEAR PM: Teaching, Outreach, and Research Through Real-Time Particulate Measurements

    NASA Astrophysics Data System (ADS)

    DeCarlo, P. F.

    2013-12-01

    An understanding of particulate matter (also called aerosols) can be made through measurement. This measurement does not change in value if it is made in a teaching, research, or outreach environment. A grant from the Camille and Henry Dreyfus Foundation provided funding to construct an instrument suite composed of 1-4 second measurements that are displayed in real-time through a software interface. This display module is called CLEAR PM (Chemistry Lessons Enabling Aerosol Realizations through Particulate Measurement), and was conceived to apply across outreach activities, teaching activities, and research activities. The construction and software design of CLEAR PM was done as part of a special topics course for chemistry and engineering graduate students at Drexel University. Measurement principles of the different (research grade) instruments were taught as part of the course, with emphasis put on the fundamental measurements and their limitations, and an introduction to data acquisition software was also integral to the teaching component. As a final project of the course graduate students were required to create a 'teaching' module that illustrates a chemistry or physics concept and utilizes the measurements of CLEAR PM. These modules ranged from gas-phase ozone chemistry creating secondary organic aerosols, to the wavelength dependent absorption profiles of wood smoke versus propane soot. The teaching modules developed by the graduate students have been used in outreach activities sponsored by The Franklin Institute and the Clean Air Council in Philadelphia, where underrepresented groups often make up a large fraction of the audience. CLEAR PM is designed to give students and citizens a hands-on opportunity to see how we measure and understand the world around us. As mentioned previously, the instruments that are part of CLEAR PM are research grade instruments, and are actively being used in research projects in the DeCarlo lab at Drexel to study particulate

  2. Real-time QEXAFS spectroscopy measures rapid precipitate formation at the mineral-water interface.

    PubMed

    Siebecker, Matthew; Li, Wei; Khalid, Syed; Sparks, Donald

    2014-09-19

    Reactions at the mineral-water interface are central to numerous geochemical processes and have consequences at local, regional and global scales. They are also important in materials science research. Kinetics greatly influences mineral-water interface reactions; however, there are few kinetic data in real-time and at the molecular scale. Here we report real-time data illustrating the rapid formation of nickel aluminium-layered double hydroxide precipitates at the mineral-water interface in a flow environment in as little as 31-40 min. Layered double hydroxides have a variety of applications in environmental remediation and materials science. The real-time data shown here enhance our fundamental understanding of the kinetics of mineral-water interface processes, such as adsorption, dissolution and precipitation, by illustrating their rapid and simultaneous occurrence in a dynamic environment. Both precipitation and adsorption can occur on the same rapid timescale.

  3. Real-time emission factor measurements of isocyanic acid from light duty gasoline vehicles.

    PubMed

    Brady, James M; Crisp, Timia A; Collier, Sonya; Kuwayama, Toshihiro; Forestieri, Sara D; Perraud, Véronique; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D; Bertram, Timothy H

    2014-10-07

    Exposure to gas-phase isocyanic acid (HNCO) has been previously shown to be associated with the development of atherosclerosis, cataracts and rheumatoid arthritis. As such, accurate emission inventories for HNCO are critical for modeling the spatial and temporal distribution of HNCO on a regional and global scale. To date, HNCO emission rates from light duty gasoline vehicles, operated under driving conditions, have not been determined. Here, we present the first measurements of real-time emission factors of isocyanic acid from a fleet of eight light duty gasoline-powered vehicles (LDGVs) tested on a chassis dynamometer using the Unified Driving Cycle (UC) at the California Air Resources Board (CARB) Haagen-Smit test facility, all of which were equipped with three-way catalytic converters. HNCO emissions were observed from all vehicles, in contrast to the idealized laboratory measurements. We report the tested fleet averaged HNCO emission factors, which depend strongly on the phase of the drive cycle; ranging from 0.46 ± 0.13 mg kg fuel(-1) during engine start to 1.70 ± 1.77 mg kg fuel(-1) during hard acceleration after the engine and catalytic converter were warm. The tested eight-car fleet average fuel based HNCO emission factor was 0.91 ± 0.58 mg kg fuel(-1), within the range previously estimated for light duty diesel-powered vehicles (0.21-3.96 mg kg fuel(-1)). Our results suggest that HNCO emissions from LDGVs represent a significant emission source in urban areas that should be accounted for in global and regional models.

  4. Real-time indoor and outdoor measurements of black carbon at primary schools

    NASA Astrophysics Data System (ADS)

    Reche, C.; Rivas, I.; Pandolfi, M.; Viana, M.; Bouso, L.; Àlvarez-Pedrerol, M.; Alastuey, A.; Sunyer, J.; Querol, X.

    2015-11-01

    Epidemiological and toxicological studies have demonstrated the association between Black Carbon in indoor and outdoor air and the occurrence of health risks. Data on air quality in schools is of special interest, as children are more vulnerable to health hazards. In this context, indoor and outdoor measurements of real-time Equivalent Black Carbon (EBC) were collected at 39 primary schools located in Barcelona (Spain), with classrooms naturally ventilated under warm weather conditions. A main contribution of road traffic emissions to indoor and outdoor EBC levels was evidenced through different approaches. Simultaneous measurements of EBC levels at schools under different traffic conditions revealed concentrations by 30-35% higher at schools exposed to higher vehicles intensities. Moreover, a significant correlation was obtained between average outdoor EBC levels at different districts of the city and the percentage of surface area in each district used for the road network (R2 = 0.61). Higher indoor than outdoor levels were recorded at some instances when the indoor sampling location was relatively closer to road traffic, even under low outdoor temperatures. Indeed, the average indoor/outdoor EBC ratios for each school correlate moderately between campaigns in spite of significant differences in temperature between sampling periods. These two facts highlight the strong dependency of the EBC levels on the distance to traffic. The peaks of exposure inside the classrooms seemed to be determined by outdoor concentrations, as shown by the parallelism between indoor and outdoor mean EBC daily cycles and the similar contribution of traffic rush hours to indoor and outdoor daily mean levels. The airtightness of the classroom was suggested as the responsible for the indoor/outdoor ratios of EBC higher than 1 recorded at nights.

  5. Assimilating Electron Density Profiles Measured by the Real Time Global Ionospheric Radio Observatory - GIRO

    NASA Astrophysics Data System (ADS)

    Reinisch, B. W.; Galkin, I. A.

    2009-04-01

    Operational applications of ionospheric models, whether they are first principles or data-driven models, rely on the accuracy of the models during quiet and disturbed conditions. Of course models can correctly describe ionospheric weather only if they assimilate measured ionospheric characteristics and electron density profiles (EDPs). For the "assimilating model" to make correct predictions, the measurements in turn must be accurate and reliable. Ionosondes provide the most accurate vertical EDPs at the site locations but do not cover all parts of the globe. Ionogram-derived EDPs have become the ground truth reference for ionospheric specification, presenting the unrivaled accuracy of the data on continuous demand for validation of alternative ionospheric techniques, including radio occultation, ultraviolet, and tomography. In recent years the digisonde network of ionosondes has grown to eighty stations and is expected to expand to more than 100 stations in the next couple of years. The new Digisonde-4D is running the Automatic Real Time Ionogram Scaler with True height inversion, ARTIST-5. The ARTIST-5 autoscaling program now calculates the EDPs together with density uncertainty limits at each height, making the data products suitable for ingestion in assimilative ionospheric models. In order to specify uncertainty at each height, two boundary profiles, inner and outer, are determined. The inner and outer boundaries reflect the uncertainties of the critical frequencies of each layer, the internal uncertainty of the starting height of the profile, and the uncertainties of the E valley model representation. The actual uncertainties are calculated from a cumulative difference characteristic representing a mismatch between automatically and manually scaled parameters (i.e., foF2, foF1) for the same ionogram. The cumulative differences are determined from statistical analysis of a large amount of ionograms for a specific station. The characteristics of interest are

  6. Measurement of the aortic annulus size by real-time three-dimensional transesophageal echocardiography.

    PubMed

    Jánosi, Rolf Alexander; Kahlert, Philipp; Plicht, Björn; Wendt, Daniel; Eggebrecht, Holger; Erbel, Raimund; Buck, Thomas

    2011-04-01

    We sought to determine the level of agreement and the reproducibility of two-dimensional (2D) transthoracic (2D-TTE), 2D transesophageal (2D-TEE) and real-time three-dimensional (3D) transesophageal echocardiography (RT3D-TEE) for measurement of aortic annulus size in patients referred for transcatheter aortic valve implantation (TAVI). Accurate preoperative assessment of the dimensions of the aortic annulus is critical for patient selection and successful implantation in those undergoing TAVI for severe aortic stenosis (AS). Annulus size was measured using 2D-TTE, 2D-TEE and RT3D-TEE in 105 patients with severe AS referred for TAVI. Agreement between echocardiographic methods and interobserver variability was assessed using the Bland-Altman method and regression analysis, respectively. The mean aortic annuli were 21,7 ± 3 mm measured with 2D-TTE, 22,6 ± 2,8 mm with 2D-TEE and 22,3 ± 2,9 mm with RT3D-TEE. The results showed a small but significant mean difference and a strong correlation between the three measurement techniques (2D-TTE vs. 2D-TEE mean difference 0,84 ± 1,85 mm, r = 0,8, p < 0,0001; 2D-TEE vs. 3D-TEE 0,27 ± 1,14 mm, r = 0,91, p < 0,02; 2D-TTE vs. 3D-TEE 0,58 ± 2,21 mm, r = 0,72, p = 0,02); however, differences between measurements amounted up to 6,1 mm. Interobserver variability for 2D-TTE and 2D-TEE was substantially higher compared with RT3D-TEE. We found significant differences in the dimensions of the aortic annulus measured by 2D-TTE, 2D-TEE and RT3D-TEE. Thus, in patients referred for TAVI, the echocardiographic method used may have an impact on TAVI strategy.

  7. Backfat thickness and longissimus dorsi real-time ultrasound measurements in light lambs.

    PubMed

    Esquivelzeta, C; Casellas, J; Fina, M; Piedrafita, J

    2012-12-01

    The aim of this study was to assess the accuracy of ultrasound measurements for predicting carcass traits in 124 Spanish pascual-type lambs (13 to 16 kg carcass weight). Ultrasound images were taken transversal and longitudinal to the vertebral column and at thoracic (TV; between 12th and 13th ribs) and lumbar (LV; between first and second lumbar vertebrae) locations. Skin thickness, subcutaneous backfat thickness (BFT), and depth (DLD), width (WLD), and area (ALD) of longissimus dorsi were obtained with ImageJ 1.42q software. After slaughter, BFT (TV, 2.30 ± 0.06 mm; LV, 2.46 ± 0.06 mm), DLD (TV, 2.47 ± 0.03 cm; LV, 2.48 ± 0.03 cm), WLD (TV, 4.50 ± 0.04 cm; LV, 4.60 ± 0.04 cm), and ALD (TV, 9.96 ± 0.12 cm(2); LV, 10.19 ± 0.13 cm(2)) were directly measured on the lamb carcass. Correlations between ultrasound and direct carcass measurements were greater than 0.61 for DLD, WLD, and ALD (P < 0.05) whereas they fluctuated between 0.32 and 0.60 for BFT (P < 0.05); moreover, correlations were significantly (P < 0.05) greater for transversal than for longitudinal views. In a similar way, linear regression analyses suggested a moderate underestimation for BFT and lumbar DLD when using real-time ultrasound technologies whereas WLD, ALD, and thoracic DLD suffered from under- and overestimation for small and large values of carcass traits, respectively. After decomposing the mean square prediction error (MSPE) for the different ultrasound measurements, we found that the error due to disturbance contributed most to the MSPE followed by the error of central tendency and the error due to regression. The SE of prediction (SEP) was also calculated as an additional precision indicator, obtaining estimates less than that in previous studies with larger lambs. In conclusion, transversal ultrasound measurements at the thoracic and lumbar levels could be a useful tool for predicting DLD, WLD, and ALD in light lambs, perhaps suffering from worse prediction properties when

  8. A Comprehensive Statistically-Based Method to Interpret Real-Time Flowing Measurements

    SciTech Connect

    Pinan Dawkrajai; Keita Yoshioka; Analis A. Romero; Ding Zhu; A.D. Hill; Larry W. Lake

    2005-10-01

    This project is motivated by the increasing use of distributed temperature sensors for real-time monitoring of complex wells (horizontal, multilateral and multi-branching wells) to infer the profiles of oil, gas, and water entry. Measured information can be used to interpret flow profiles along the wellbore including junction and build section. In this second project year, we have completed a forward model to predict temperature and pressure profiles in complex wells. As a comprehensive temperature model, we have developed an analytical reservoir flow model which takes into account Joule-Thomson effects in the near well vicinity and multiphase non-isothermal producing wellbore model, and couples those models accounting mass and heat transfer between them. For further inferences such as water coning or gas evaporation, we will need a numerical non-isothermal reservoir simulator, and unlike existing (thermal recovery, geothermal) simulators, it should capture subtle temperature change occurring in a normal production. We will show the results from the analytical coupled model (analytical reservoir solution coupled with numerical multi-segment well model) to infer the anomalous temperature or pressure profiles under various conditions, and the preliminary results from the numerical coupled reservoir model which solves full matrix including wellbore grids. We applied Ramey's model to the build section and used an enthalpy balance to infer the temperature profile at the junction. The multilateral wellbore temperature model was applied to a wide range of cases varying fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section.

  9. Real-time mRNA measurement during an in vitro transcription and translation reaction using binary probes.

    PubMed

    Niederholtmeyer, Henrike; Xu, Ling; Maerkl, Sebastian J

    2013-08-16

    In vitro transcription and translation reactions have become popular for a bottom-up approach to synthetic biology. Concentrations of the mRNA intermediate are rarely determined, although knowledge of synthesis and degradation rates could facilitate rational engineering of in vitro systems. We designed binary probes to measure mRNA dynamics during cell-free protein synthesis by fluorescence resonance energy transfer. We tested different mRNA variants and show that the location and sequence environment of the probe target sites are important parameters for probe association kinetics and output signal. Best suited for sensitive real-time quantitation of mRNA was a target site located in the 3' untranslated region, which we designed to reduce secondary structure. We used this probe-target pair to refine our knowledge of mRNA dynamics in the commercially available PURE cell-free protein synthesis system and characterized the effect of TetR repressor on mRNA synthesis rates from a T7 promoter.

  10. Quantitative real-time PCR and fluorescence in situ hybridization approaches for enumerating Brevundimonas diminuta in drinking water.

    PubMed

    Donofrio, Robert S; Bestervelt, Lorelle L; Saha, Ratul; Bagley, Susan T

    2010-09-01

    Brevundimonas diminuta is a small Gram-negative bacterium used for validation of membranes and filters used in the pharmaceutical and drinking water treatment industries. Current assays are time consuming, nonselective, and may be subject to interference by competing indigenous microorganisms. The focus of this study is to develop rapid and specific enumeration methodologies for B. diminuta. Quantitative real-time polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) assays were developed based on the gyrB (1,166 bp) and rpoD (829 bp) gene sequences of B. diminuta ATCC 19146. Species-specific primers and probes were designed, and a 100-200 bp segment of each gene was targeted in the qPCR studies. For both the qPCR and FISH assays, an internal 25 bp sequence was selected for use as a TaqMan probe (labeled with 6-FAM and a Black Hole Quencher). Probe specificity studies, conducted against Gram-negative and Gram-positive reference strains as well as environmental strains, revealed high specificity of the primer/probe pairs to B. diminuta. Sensitivities of the qPCR reactions using purified genomic DNA from B. diminuta were determined to be 0.89 pg for rpoD and 8.9 pg for gyrB. The feasibility of using whole-cell B. diminuta suspensions directly with the rpoD qPCR protocol was also evaluated. The greatest sensitivity observed for B. diminuta was 1 x 10(3) colony forming units (CFU) per mL when tryptic soy broth was used as the growth medium. When compared with direct microscopic enumeration using a 5' 6-FAM FISH probe, traditional plating methods showed significant underestimation of B. diminuta concentration (P = 0.01) when this organism was cultivated in saline lactose broth. The results of this investigation demonstrate that qPCR and FISH are effective methods for rapid (<4 h) enumeration of B. diminuta and may be viable alternatives to plating when validating drinking water filtration systems.

  11. Real-time Redox Measurements during Endoplasmic Reticulum Stress Reveal Interlinked Protein Folding Functions

    PubMed Central

    Merksamer, Philip I.; Trusina, Ala; Papa, Feroz R.

    2008-01-01

    SUMMARY Disruption of protein folding in the endoplasmic reticulum (ER) causes unfolded proteins to accumulate, triggering the unfolded protein response (UPR). UPR outputs in turn decrease ER unfolded proteins to close a negative feedback loop. However, because it is infeasible to directly measure the concentration of unfolded proteins in vivo, cells are generically described as experiencing “ER stress” whenever the UPR is active. Because ER redox potential is optimized for oxidative protein folding, we reasoned that measureable redox changes should accompany unfolded protein accumulation. To test this concept, we employed fluorescent protein reporters to dynamically measure ER redox status and UPR activity in single cells. Using these tools, we show that diverse stressors, both experimental and physiological, compromise ER protein oxidation when UPR-imposed homeostatic control is lost. Using genetic analysis we uncovered redox heterogeneities in isogenic cell populations, and revealed functional interlinks between ER protein folding, modification, and quality control systems. PMID:19026441

  12. A 32-channel photon counting module with embedded auto/cross-correlators for real-time parallel fluorescence correlation spectroscopy

    SciTech Connect

    Gong, S.; Labanca, I.; Rech, I.; Ghioni, M.

    2014-10-15

    Fluorescence correlation spectroscopy (FCS) is a well-established technique to study binding interactions or the diffusion of fluorescently labeled biomolecules in vitro and in vivo. Fast FCS experiments require parallel data acquisition and analysis which can be achieved by exploiting a multi-channel Single Photon Avalanche Diode (SPAD) array and a corresponding multi-input correlator. This paper reports a 32-channel FPGA based correlator able to perform 32 auto/cross-correlations simultaneously over a lag-time ranging from 10 ns up to 150 ms. The correlator is included in a 32 × 1 SPAD array module, providing a compact and flexible instrument for high throughput FCS experiments. However, some inherent features of SPAD arrays, namely afterpulsing and optical crosstalk effects, may introduce distortions in the measurement of auto- and cross-correlation functions. We investigated these limitations to assess their impact on the module and evaluate possible workarounds.

  13. A 32-channel photon counting module with embedded auto/cross-correlators for real-time parallel fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Gong, S.; Labanca, I.; Rech, I.; Ghioni, M.

    2014-10-01

    Fluorescence correlation spectroscopy (FCS) is a well-established technique to study binding interactions or the diffusion of fluorescently labeled biomolecules in vitro and in vivo. Fast FCS experiments require parallel data acquisition and analysis which can be achieved by exploiting a multi-channel Single Photon Avalanche Diode (SPAD) array and a corresponding multi-input correlator. This paper reports a 32-channel FPGA based correlator able to perform 32 auto/cross-correlations simultaneously over a lag-time ranging from 10 ns up to 150 ms. The correlator is included in a 32 × 1 SPAD array module, providing a compact and flexible instrument for high throughput FCS experiments. However, some inherent features of SPAD arrays, namely afterpulsing and optical crosstalk effects, may introduce distortions in the measurement of auto- and cross-correlation functions. We investigated these limitations to assess their impact on the module and evaluate possible workarounds.

  14. A 32-channel photon counting module with embedded auto/cross-correlators for real-time parallel fluorescence correlation spectroscopy

    PubMed Central

    Gong, S.; Labanca, I.; Rech, I.; Ghioni, M.

    2014-01-01

    Fluorescence correlation spectroscopy (FCS) is a well-established technique to study binding interactions or the diffusion of fluorescently labeled biomolecules in vitro and in vivo. Fast FCS experiments require parallel data acquisition and analysis which can be achieved by exploiting a multi-channel Single Photon Avalanche Diode (SPAD) array and a corresponding multi-input correlator. This paper reports a 32-channel FPGA based correlator able to perform 32 auto/cross-correlations simultaneously over a lag-time ranging from 10 ns up to 150 ms. The correlator is included in a 32 × 1 SPAD array module, providing a compact and flexible instrument for high throughput FCS experiments. However, some inherent features of SPAD arrays, namely afterpulsing and optical crosstalk effects, may introduce distortions in the measurement of auto- and cross-correlation functions. We investigated these limitations to assess their impact on the module and evaluate possible workarounds. PMID:25362365

  15. Unmanned Airborne System Deployment at Turrialba Volcano for Real Time Eruptive Cloud Measurements

    NASA Astrophysics Data System (ADS)

    Diaz, J. A.; Pieri, D. C.; Fladeland, M. M.; Bland, G.; Corrales, E.; Alan, A., Jr.; Alegria, O.; Kolyer, R.

    2015-12-01

    The development of small unmanned aerial systems (sUAS) with a variety of instrument packages enables in situ and proximal remote sensing measurements of volcanic plumes, even when the active conditions of the volcano do not allow volcanologists and emergency response personnel to get too close to the erupting crater. This has been demonstrated this year by flying a sUAS through the heavy ash driven erupting volcanic cloud of Turrialba Volcano, while conducting real time in situ measurement of gases over the crater summit. The event also achieved the collection of newly released ash samples from the erupting volcano. The interception of the Turrialba ash cloud occurred during the CARTA 2015 field campaign carried out as part of an ongoing program for remote sensing satellite calibration and validation purposes, using active volcanic plumes. These deployments are timed to support overflights of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard the NASA Terra satellite on a bimonthly basis using airborne platforms such as tethered balloons, free-flying fixed wing small UAVs at altitudes up to 12.5Kft ASL within about a 5km radius of the summit crater. The onboard instrument includes the MiniGas payload which consists of an array of single electrochemical and infrared gas detectors (SO2, H2S CO2), temperature, pressure, relative humidity and GPS sensors, all connected to an Arduino-based board, with data collected at 1Hz. Data are both stored onboard and sent by telemetry to the ground operator within a 3 km range. The UAV can also carry visible and infrared cameras as well as other payloads, such as a UAV-MS payload that is currently under development for mass spectrometer-based in situ measurements. The presentation describes the ongoing UAV- based in situ remote sensing validation program at Turrialba Volcano, the results of a fly-through the eruptive cloud, as well as future plans to continue these efforts. Work presented here was

  16. Automated Historical and Real-Time Cyclone Discovery With Multimodal Remote Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Ho, S.; Talukder, A.; Liu, T.; Tang, W.; Bingham, A.

    2008-12-01

    methodology can be applied to (i) historical data to support Earth scientists in climate modeling, cyclonic-climate interactions, and obtain a better understanding of the cause and effects of cyclone (e.g. cyclo-genesis), and (ii) automatic cyclone discovery in near real-time using streaming satellite to support and improve the planning of global cyclone field campaigns. Additional satellite data from GOES and other orbiting satellites can be easily assimilated and integrated into our automated cyclone detection and tracking module to improve the temporal tracking accuracy of cyclones down to ½ hr and reduce the incidence of false alarms.

  17. Aptamer/Graphene Quantum Dots Nanocomposite Capped Fluorescent Mesoporous Silica Nanoparticles for Intracellular Drug Delivery and Real-Time Monitoring of Drug Release.

    PubMed

    Zheng, Fen-Fen; Zhang, Peng-Hui; Xi, Yu; Chen, Jing-Jia; Li, Ling-Ling; Zhu, Jun-Jie

    2015-12-01

    Great challenges in investigating the release of drug in complex cellular microenvironments necessitate the development of stimuli-responsive drug delivery systems with real-time monitoring capability. In this work, a smart drug nanocarrier based on fluorescence resonance energy transfer (FRET) is fabricated by capping graphene quantum dots (GQDs, the acceptor) onto fluorescent mesoporous silica nanoparticles (FMSNs, the donor) via ATP aptamer for real-time monitoring of ATP-triggered drug release. Under extracellular conditions, the fluorescence of FMSNs remains in the "off" state in the low ATP level which is unable to trigger the release of drug. Once specifically recognized and internalized into the target tumor cells by AS1411 aptamer, in the ATP-rich cytoplasm, the conformation switch of the ATP aptamer causes the shedding of the GQDs from the nanocarriers, leading to the release of the loaded drugs and consequently severe cytotoxicity. Simultaneously, the fluorescence of FMSNs turns "on" along with the dissociation of GQDs, which allows real-time monitoring of the release of drug from the pores. Such a drug delivery system features high specificity of dual-target recognition with AS1411 and ATP aptamer as well as high sensitivity of the FRET-based monitoring strategy. Thus, the proposed multifunctional ATP triggered FRET-nanocarriers will find potential applications for versatile drug-release monitoring, efficient drug transport, and targeted cancer therapeutics.

  18. Near Real-Time Isotopic Measurements of Carbon Dioxide from Outgassing Volcanoes

    NASA Astrophysics Data System (ADS)

    Stix, J.; Lucic, G.; Malowany, K.

    2014-12-01

    For the past several years we have been using a Picarro G1101-i isotopic mass analyzer to study the behavior of carbon dioxide emanating from active volcanoes. Because of its portability (it weighs about 30 kg), the instrument accompanies us on our field campaigns. Typically, we collect gas samples during the day and analyze them in the evening. The result is near-real-time isotopic measurements of CO2, and we are thus able to plan and adjust our field campaigns according to the results that we obtain on a continual basis. This is the primary advantage of the instrument. The G1101-i requires about 350 watts of power, typically provided by wall current with an uninterruptible power supply between the wall and instrument to deal with power fluctuations and outages. We calibrate the instrument every 2-5 days with a series of four well-characterized gas standards which we bring with us into the field in evacuated glass containers. Calibrations are typically robust and highly linear, with sub per mil precision. We also normally obtain a few samples which we analyze both by the G1101-i and later by mass spectrometry, in order to provide an independent means of checking our accuracy. Standards and samples are typically analyzed at similar CO2 concentrations to minimize any concentration-dependent effects on the isotopic analysis, even though these are generally small to negligible. Our applications so far have been focused at one caldera system and one subduction-related stratovolcano. We have analyzed soil gases at Long Valley caldera, California, to study the interplay of volcanic and tectonic controls upon diffuse CO2 release. We have analyzed CO2 in the the plume of Turrialba volcano, Costa Rica, to identify the volcanic isotopic signal and understand the mixing of the plume with surrounding atmosphere. At both localities, with appropriate dilutions as needed, we have been able to analyze the isotopic signal for CO2 concentrations ranging from atmospheric (400 ppm) to

  19. Internal flow measurements of the SSME fuel preburner injector element using real time neutron radiography

    NASA Technical Reports Server (NTRS)

    Lindsay, John T.; Elam, Sandy; Koblish, Ted; Lee, Phil; Mcauliffe, Dave

    1990-01-01

    Due to observations of unsteady flow in the Space Shuttle Main Engine fuel preburner injector element, several flow studies have been performed. Real time neutron radiography tests were recently completed. This technique provided real time images of MiL-c-7024 and Freon-22 flow through an aluminum liquid oxygen post model at three back pressures (0, 150, and 545 psig) and pressure drops up to 1000 psid. Separated flow appeared only while operating at back pressures of 0 and 150 psig. The behavior of separated flow was similar to that observed for water in a 3x acrylic model of the LOX post. On the average, separated flow appeared to reattach near the exit of the post when the ratio of pressure drop to supply pressure was about 0.75.

  20. Internal flow measurements of the SSME fuel preburner injector element using real time neutron radiography

    NASA Technical Reports Server (NTRS)

    Lindsay, John T.; Elam, Sandy; Koblish, Ted; Lee, Phil; Mcauliffe, Dave

    1990-01-01

    Due to observations of unsteady flow in the Space Shuttle Main Engine fuel preburner injector element, several flow studies have been performed. Real time neutron radiography tests were recently completed. This technique provided real time images of MiL-c-7024 and Freon-22 flow through an aluminum liquid oxygen post model at three back pressures (0, 150, and 545 psig) and pressure drops up to 1000 psid. Separated flow appeared only while operating at back pressures of 0 and 150 psig. The behavior of separated flow was similar to that observed for water in a 3x acrylic model of the LOX post. On the average, separated flow appeared to reattach near the exit of the post when the ratio of pressure drop to supply pressure was about 0.75.

  1. XpertTrack: Precision Autonomous Measuring Device Developed for Real Time Shipments Tracker

    PubMed Central

    Viman, Liviu; Daraban, Mihai; Fizesan, Raul; Iuonas, Mircea

    2016-01-01

    This paper proposes a software and hardware solution for real time condition monitoring applications. The proposed device, called XpertTrack, exchanges data through the GPRS protocol over a GSM network and monitories temperature and vibrations of critical merchandise during commercial shipments anywhere on the globe. Another feature of this real time tracker is to provide GPS and GSM positioning with a precision of 10 m or less. In order to interpret the condition of the merchandise, the data acquisition, analysis and visualization are done with 0.1 °C accuracy for the temperature sensor, and 10 levels of shock sensitivity for the acceleration sensor. In addition to this, the architecture allows increasing the number and the types of sensors, so that companies can use this flexible solution to monitor a large percentage of their fleet. PMID:26978360

  2. Real-Time Leaky Lamb Wave Spectrum Measurement and Its Application to NDE of Composites

    NASA Technical Reports Server (NTRS)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph

    1999-01-01

    Numerous analytical and theoretical studies of the behavior of leaky Lamb waves (LLW) in composite materials were documented in the literature. One of the key issues that are constraining the application of this method as a practical tool is the amount of data that needs to be acquired and the slow process that is involved with such experiments. Recently, a methodology that allows quasi real-time acquisition of LLW dispersion data was developed. At each angle of incidence the reflection spectrum is available in real time from the experimental setup and it can be used for rapid detection of the defects. This technique can be used to rapidly acquire the various plate wave modes along various angles of incidence for the characterization of the material elastic properties. The experimental method and data acquisition technique will be described in this paper. Experimental data was used to examine a series of flaws including porosity and delaminations and demonstrated the efficiency of the developed technique.

  3. Real-time aortic pulse wave velocity measurement during exercise stress testing.

    PubMed

    Roberts, Paul A; Cowan, Brett R; Liu, Yingmin; Lin, Aaron C W; Nielsen, Poul M F; Taberner, Andrew J; Stewart, Ralph A H; Lam, Hoi Ieng; Young, Alistair A

    2015-10-05

    Pulse wave velocity (PWV), a measure of arterial stiffness, has been demonstrated to be an independent predictor of adverse cardiovascular outcomes. This can be derived non-invasively using cardiovascular magnetic resonance (CMR). Changes in PWV during exercise may reveal further information on vascular pathology. However, most known CMR methods for quantifying PWV are currently unsuitable for exercise stress testing. A velocity-sensitive real-time acquisition and evaluation (RACE) pulse sequence was adapted to provide interleaved acquisition of two locations in the descending aorta (at the level of the pulmonary artery bifurcation and above the renal arteries) at 7.8 ms temporal resolution. An automated method was used to calculate the foot-to-foot transit time of the velocity pulse wave. The RACE method was validated against a standard gated phase contrast (STD) method in flexible tube phantoms using a pulsatile flow pump. The method was applied in 50 healthy volunteers (28 males) aged 22-75 years using a MR-compatible cycle ergometer to achieve moderate work rate (38 ± 22 W, with a 31 ± 12 bpm increase in heart rate) in the supine position. Central pulse pressures were estimated using a MR-compatible brachial device. Scan-rescan reproducibility was evaluated in nine volunteers. Phantom PWV was 22 m/s (STD) vs. 26 ± 5 m/s (RACE) for a butyl rubber tube, and 5.5 vs. 6.1 ± 0.3 m/s for a latex rubber tube. In healthy volunteers PWV increased with age at both rest (R(2) = 0.31 p < 0.001) and exercise (R(2) = 0.40, p < 0.001). PWV was significantly increased at exercise relative to rest (0.71 ± 2.2 m/s, p = 0.04). Scan-rescan reproducibility at rest was -0.21 ± 0.68 m/s (n = 9). This study demonstrates the validity of CMR in the evaluation of PWV during exercise in healthy subjects. The results support the feasibility of using this method in evaluating of patients with systemic aortic disease.

  4. Mouse Liver Mitochondria Isolation, Size Fractionation, and Real-time MOMP Measurement

    PubMed Central

    Renault, Thibaud T.; Luna-Vargas, Mark P.A.; Chipuk, Jerry E.

    2016-01-01

    The mitochondrial pathway of apoptosis involves a complex interplay between dozens of proteins and lipids, and is also dependent on the shape and size of mitochondria. The use of cellular models in past studies has not been ideal for investigating how the complex multi-factor interplay regulates the molecular mechanisms of mitochondrial outer membrane permeabilization (MOMP). Isolated systems have proven to be a paradigm to deconstruct MOMP into individual steps and to study the behavior of each subset of MOMP regulators. In particular, isolated mitochondria are key to in vitro studies of the BCL-2 family proteins, a complex family of pro-survival and pro-apoptotic proteins that directly control the mitochondrial pathway of apoptosis (Renault et al., 2013). In this protocol, we describe three complementary procedures for investigating in real-time the effects of MOMP regulators using isolated mitochondria. The first procedure is “Liver mitochondria isolation” in which the liver is dissected from mice to obtain mitochondria. “Mitochondria labeling with JC-1 and size fractionation” is the second procedure that describes a method to label, fractionate by size and standardize subpopulations of mitochondria. Finally, the “Real-time MOMP measurements” protocol allows to follow MOMP in real-time on isolated mitochondria. The aforementioned procedures were used to determine in vitro the role of mitochondrial membrane shape at the level of isolated cells and isolated mitochondria (Renault et al., 2015). PMID:28093578

  5. Real-time structured light-based otoscopy for quantitative measurement of eardrum deformation

    NASA Astrophysics Data System (ADS)

    Van der Jeught, Sam; Dirckx, Joris J. J.

    2017-01-01

    An otological profilometry device based on real-time structured light triangulation is presented. A clinical otoscope head is mounted onto a custom-handheld unit containing both a small digital light projector and a high-speed digital camera. Digital fringe patterns are projected onto the eardrum surface and are recorded at a rate of 120 unique frames per second. The relative angle between projection and camera axes causes the projected patterns to appear deformed by the eardrum shape, allowing its full-field three-dimensional (3-D) surface map to be reconstructed. By combining hardware triggering between projector and camera with a dedicated parallel processing pipeline, the proposed system is capable of acquiring a live stream of point clouds of over 300,000 data points per frame at a rate of 40 Hz. Real-time eardrum profilometry adds an additional dimension of depth to the standard two-dimensional otoscopy image and provides a noninvasive tool to enhance the qualitative depth perception of the clinical operator with quantitative 3-D data. Visualization of the eardrum from different perspectives can improve the diagnosis of existing and the detection of impending middle ear pathology. The capability of the device to detect small middle ear pressure changes by monitoring eardrum deformation in real time is demonstrated.

  6. High-resolution real-time 3D shape measurement on a portable device

    NASA Astrophysics Data System (ADS)

    Karpinsky, Nikolaus; Hoke, Morgan; Chen, Vincent; Zhang, Song

    2013-09-01

    Recent advances in technology have enabled the acquisition of high-resolution 3D models in real-time though the use of structured light scanning techniques. While these advances are impressive, they require large amounts of computing power, thus being limited to using large desktop computers with high end CPUs and sometimes GPUs. This is undesirable in making high-resolution real-time 3D scanners ubiquitous in our mobile lives. To address this issue, this work describes and demonstrates a real-time 3D scanning system that is realized on a mobile device, namely a laptop computer, which can achieve speeds of 20fps 3D at a resolution of 640x480 per frame. By utilizing a graphics processing unit (GPU) as a multipurpose parallel processor, along with a parallel phase shifting technique, we are able to realize the entire 3D processing pipeline in parallel. To mitigate high speed camera transfer problems, which typically require a dedicated frame grabber, we make use of USB 3.0 along with direct memory access (DMA) to transfer camera images to the GPU. To demonstrate the effectiveness of the technique, we experiment with the scanner on both static geometry of a statue and dynamic geometry of a deforming material sample in front of the system.

  7. Real-time in situ electron spin resonance measurements on fungal spores of Penicillium digitatum during exposure of oxygen plasmas

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kenji; Mizuno, Hiroko; Tanaka, Hiromasa; Tamiya, Kazuhiro; Hashizume, Hiroshi; Ohta, Takayuki; Ito, Masafumi; Iseki, Sachiko; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2012-07-01

    We report the kinetic analysis of free radicals on fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge using real time in situ electron spin resonance (ESR) measurements. We have obtained information that the ESR signal from the spores was observed and preliminarily assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal is possibly linked to the inactivation of the fungal spore. The real-time in situ ESR has proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens.

  8. A CCD-based fluorescence imaging system for real-time loop-mediated isothermal amplification-based rapid and sensitive detection of waterborne pathogens on microchips.

    PubMed

    Ahmad, Farhan; Seyrig, Gregoire; Tourlousse, Dieter M; Stedtfeld, Robert D; Tiedje, James M; Hashsham, Syed A

    2011-10-01

    Rapid, sensitive, and low-cost pathogen diagnostic systems are needed for early disease diagnosis and treatment, especially in resource-limited settings. This study reports a low-cost charge-coupled device (CCD)-based fluorescence imaging system for rapid detection of waterborne pathogens by isothermal gene amplification in disposable microchips. Fluorescence imaging capability of this monochromatic CCD camera is evaluated by optimizing the gain, offset, and exposure time. This imaging system is validated for 12 virulence genes of major waterborne pathogens on cyclic olefin polymer (COP) microchips, using SYTO-82 dye and real time fluorescence loop-mediated isothermal amplification referred here as microRT(f)-LAMP. Signal-to-noise ratio (SNR) and threshold time (Tt) of microRT(f)-LAMP assays are compared with those from a commercial real-time polymerase chain reaction (PCR) instrument. Applying a CCD exposure of 5 s to 10(5) starting DNA copies of microRT(f)-LAMP assays increases the SNR by 8-fold and reduces the Tt by 9.8 min in comparison to a commercial real-time PCR instrument. Additionally, single copy level sensitivity for Campylobacter jejuni 0414 gene is obtained for microRT(f)-LAMP with a Tt of 19 min, which is half the time of the commercial real-time PCR instrument. Due to the control over the exposure time and the wide field imaging capability of CCD, this low-cost fluorescence imaging system has the potential for rapid and parallel detection of pathogenic microorganisms in high throughput microfluidic chips.

  9. High-speed real-time 3-D coordinates measurement based on fringe projection profilometry considering camera lens distortion

    NASA Astrophysics Data System (ADS)

    Feng, Shijie; Chen, Qian; Zuo, Chao; Sun, Jiasong; Yu, Shi Ling

    2014-10-01

    Optical three-dimensional (3-D) profilometry is gaining increasing attention for its simplicity, flexibility, high accuracy, and non-contact nature. Recent advances in imaging sensors and digital projection technology further its progress in high-speed, real-time applications, enabling 3-D shapes reconstruction of moving objects and dynamic scenes. However, the camera lens is never perfect and the lens distortion does influence the accuracy of the measurement result, which is often overlooked in the existing real-time 3-D shape measurement systems. To this end, here we present a novel high-speed real-time 3-D coordinates measuring technique based on fringe projection with the consideration of the camera lens distortion. A pixel mapping relation between a distorted image and a corrected one is pre-determined and stored in computer memory for real-time fringe correction. The out-of-plane height is obtained firstly and the acquisition for the two corresponding in-plane coordinates follows on the basis of the solved height. Besides, a method of lookup table (LUT) is introduced as well for fast data processing. Our experimental results reveal that the measurement error of the in-plane coordinates has been reduced by one order of magnitude and the accuracy of the out-plane coordinate been tripled after the distortions being eliminated. Moreover, owing to the generated LUTs, a 3-D reconstruction speed of 92.34 frames per second can be achieved.

  10. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    EPA Science Inventory

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  11. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    EPA Science Inventory

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  12. Development of a methodology to measure the effect of ergot alkaloids on forestomach motility using real-time wireless telemetry

    USDA-ARS?s Scientific Manuscript database

    The objectives of these experiments were to characterize rumen motility patterns of cattle fed once daily using a real-time wireless telemetry system, determine when to measure rumen motility with this system, and determine the effect of ruminal dosing of ergot alkaloids on rumen motility. Ruminally...

  13. Evaluation of some software measuring displacements using GPS in real-time

    USGS Publications Warehouse

    Langbein, John

    2006-01-01

    For the past decade, the USGS has been monitoring deformation at various locations in the western United States using continuous GPS. The main focus of these measurements are estimates of displacement averaged over one day. Essentially, these consist of recording at 30 seconds intervals the carrier-frequency phase-data (equivalent to travel-time) between a GPS receiver and the GPS satellite network. In turn, these observations, which are converted to pseudo—ranges, are processed using one of the “research grade” programs (GIPSY, Zumberge et al., or GAMIT, wwwgpsg.mit.edu/~simon/gtgk) to estimate the position of the GPS receiver averaged over 24 hours. However, it is possible and desirable to estimate the position of the receiver (actually the antenna) more frequently and to do this within a few seconds of the time actual measurement (known as real-time). A recent example, the 2004 Magnitude 6, Parkfield, California earthquake, demonstrated that having GPS estimates of position more frequently than simply a daily average is required if one requires discrimination between co-seismic and post-seismic deformation (Langbein et al., 2006). The high-rate estimates of position obtained at Parkfield show that post-seismic deformation started less than one-hour after the mainshock and that this deformation was roughly the same magnitude as the co-seismic deformation. The high-rate solutions for Parkfield were done by others including Yehuda Bock at UCSD and Kristine Larson at U. of Colorado, but not the USGS. The Parkfield experience points out the need for an in-house capability by the USGS to be able to accurately measure co-seismic displacements and other rapid, deformation signals using GPS. This applies to both the Earthquake and Volcano Hazard programs. Although at many locations where we monitor deformation, we have strainmeters and tiltmeters in addition to GPS which, in principle, are far more sensitive to rapid deformation over periods of less than a day

  14. Rapid detection of Wuchereria bancrofti and Brugia malayi in mosquito vectors (Diptera: Culicidae) using a real-time fluorescence resonance energy transfer multiplex PCR and melting curve analysis.

    PubMed

    Intapan, Pewpan M; Thanchomnang, Tongjit; Lulitanond, Viraphong; Maleewong, Wanchai

    2009-01-01

    We developed a single-step real-time fluorescence resonance energy transfer (FRET) multiplex polymerase chain reaction (PCR) merged with melting curve analysis for the detection of Wuchereria bancrofti and Brugia malayi DNA in blood-fed mosquitoes. Real-time FRET multiplex PCR is based on fluorescence melting curve analysis of a hybrid of amplicons generated from two families of repeated DNA elements: the 188 bp SspI repeated sequence, specific to W. bancrofti, and the 153-bp HhaI repeated sequence, specific to the genus Brugia and two pairs of specific fluorophore-labeled probes. Both W. bancrofti and B. malayi can be differentially detected in infected vectors by this process through their different fluorescence channel and melting temperatures. The assay could distinguish both human filarial DNAs in infected vectors from the DNAs of Dirofilaria immitis- and Plasmodium falciparum-infected human red blood cells and noninfected mosquitoes and human leukocytes. The technique showed 100% sensitivity and specificity and offers a rapid and reliable procedure for differentially identifying lymphatic filariasis. The introduced real-time FRET multiplex PCR can reduce labor time and reagent costs and is not prone to carry over contamination. The test can be used to screen mosquito vectors in endemic areas and therefore should be a useful diagnostic tool for the evaluation of infection rate of the mosquito populations and for xenomonitoring in the community after eradication programs such as the Global Program to Eliminate Lymphatic Filariasis.

  15. Gold Nanoclusters-Indocyanine Green Nanoprobes for Synchronous Cancer Imaging, Treatment, and Real-Time Monitoring Based on Fluorescence Resonance Energy Transfer.

    PubMed

    Cui, Haodong; Hu, Dehong; Zhang, Jingnan; Gao, Guanhui; Chen, Ze; Li, Wenjun; Gong, Ping; Sheng, Zonghai; Cai, Lintao

    2017-08-02

    Well-designed gold nanoclusters-indocyanine green nanoprobes (Au NCs-INPs) have been developed by the conjugation of Au NC assemblies with indocyanine green (ICG) for the therapeutic real-time monitoring based on fluorescence resonance energy transfer (FRET). The synthesized Au NCs-INPs demonstrated the improved cellular uptake and effective tumor targeting because of the enhanced permeability and retention effect and the gp60-mediated secreted protein acidic and rich in cysteine combined transport pathway, suggesting excellent dual-modal near-infrared fluorescence and photoacoustic imaging. Moreover, the simultaneous photodynamic therapy (PDT) and photothermal therapy (PTT) of Au NCs-INPs exhibited higher cancer cell killing and tumor removal efficiency than those of PDT or PTT alone. More importantly, a promising therapeutic monitoring strategy was performed based on FRET between Au NCs and ICG, suggesting that Au NCs-INPs could be utilized to evaluate the therapeutic response by real-time monitoring the change in Au NCs in fluorescence intensity together with ICG supersession. Therefore, Au NCs-INPs as a novel photosensitizer have great potentials for combined tumor imaging, therapy, and therapeutic monitoring in real time.

  16. Visual in vivo degradation of injectable hydrogel by real-time and non-invasive tracking using carbon nanodots as fluorescent indicator.

    PubMed

    Wang, Lei; Li, Baoqiang; Xu, Feng; Li, Ying; Xu, Zheheng; Wei, Daqing; Feng, Yujie; Wang, Yaming; Jia, Dechang; Zhou, Yu

    2017-11-01

    Visual in vivo degradation of hydrogel by fluorescence-related tracking and monitoring is crucial for quantitatively depicting the degradation profile of hydrogel in a real-time and non-invasive manner. However, the commonly used fluorescent imaging usually encounters limitations, such as intrinsic photobleaching of organic fluorophores and uncertain perturbation of degradation induced by the change in molecular structure of hydrogel. To address these problems, we employed photoluminescent carbon nanodots (CNDs) with low photobleaching, red emission and good biocompatibility as fluorescent indicator for real-time and non-invasive visual in vitro/in vivo degradation of injectable hydrogels that are mixed with CNDs. The in vitro/in vivo toxicity results suggested that CNDs were nontoxic. The embedded CNDs in hydrogels did not diffuse outside in the absence of hydrogel degradation. We had acquired similar degradation kinetics (PBS-Enzyme) between gravimetric and visual determination, and established mathematical equation to quantitatively depict in vitro degradation profile of hydrogels for the predication of in vivo hydrogel degradation. Based on the in vitro data, we developed a visual platform that could quantitatively depict in vivo degradation behavior of new injectable biomaterials by real-time and non-invasive fluorescence tracking. This fluorescence-related visual imaging methodology could be applied to subcutaneous degradation of injectable hydrogel with down to 7 mm depth in small animal trials so far. This fluorescence-related visual imaging methodology holds great potentials for rational design and convenient in vivo screening of biocompatible and biodegradable injectable hydrogels in tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Real-time, continuous, fluorescence sensing in a freely-moving subject with an implanted hybrid VCSEL/CMOS biosensor

    PubMed Central

    O’Sullivan, Thomas D.; Heitz, Roxana T.; Parashurama, Natesh; Barkin, David B.; Wooley, Bruce A.; Gambhir, Sanjiv S.; Harris, James S.; Levi, Ofer

    2013-01-01

    Performance improvements in instrumentation for optical imaging have contributed greatly to molecular imaging in living subjects. In order to advance molecular imaging in freely moving, untethered subjects, we designed a miniature vertical-cavity surface-emitting laser (VCSEL)-based biosensor measuring 1cm3 and weighing 0.7g that accurately detects both fluorophore and tumor-targeted molecular probes in small animals. We integrated a critical enabling component, a complementary metal-oxide semiconductor (CMOS) read-out integrated circuit, which digitized the fluorescence signal to achieve autofluorescence-limited sensitivity. After surgical implantation of the lightweight sensor for two weeks, we obtained continuous and dynamic fluorophore measurements while the subject was un-anesthetized and mobile. The technology demonstrated here represents a critical step in the path toward untethered optical sensing using an integrated optoelectronic implant. PMID:24009996

  18. Real-Time Measurement of Rates of Outdoor Airflow into HVACSystems: A Field Study of Three Technologies

    SciTech Connect

    Fisk, William J.; Sullivan, Douglas P.; Faulkner, David

    2005-09-01

    Technologies for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems are now available commercially. Our prior papers reported on laboratory-based evaluations of these measurement technologies and this document describes the methods and results of a field study of the accuracy of three of these technologies. From the field study data, we determined that neither wind speed nor wind direction have an important adverse impact on measurement accuracy. The field study confirmed that these three measurement technologies can provide reasonably accurate measurements of outdoor air intake rates in field settings, if the pressure signals are measured with high accuracy. Some of the pressure transducers marketed for use with commercial HVAC systems were determined to be sufficiently accurate for this application. Given the significant impact of OA flow rates on both energy use and occupant health, more widespread use of technologies that provide for real time measurements of OA flow rates seems warranted.

  19. Portable, real-time alloy identification of metallic wear debris from machinery lubrication systems: laser-induced breakdown spectroscopy versus x-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Suresh, Pooja

    2014-05-01

    Alloy identification of oil-borne wear debris captured on chip detectors, filters and magnetic plugs allows the machinery maintainer to assess the health of the engine or gearbox and identify specific component damage. Today, such identification can be achieved in real time using portable, at-line laser-induced breakdown spectroscopy (LIBS) and Xray fluorescence (XRF) instruments. Both techniques can be utilized in various industries including aviation, marine, railways, heavy diesel and other industrial machinery with, however, some substantial differences in application and instrument performance. In this work, the performances of a LIBS and an XRF instrument are compared based on measurements of a wide range of typical aerospace alloys including steels, titanium, aluminum and nickel alloys. Measurement results were analyzed with a staged correlation technique specifically developed for the purposes of this study - identifying the particle alloy composition using a pre-recorded library of spectral signatures. The analysis is performed in two stages: first, the base element of the alloy is determined by correlation with the stored elemental spectra and then, the alloy is identified by matching the particle's spectral signature using parametric correlation against the stored spectra of all alloys that have the same base element. The correlation analysis has achieved highly repeatable discrimination between alloys of similar composition. Portable LIBS demonstrates higher detection accuracy and better identification of alloys comprising lighter elements as compared to that of the portable XRF system, and reveals a significant reduction in the analysis time over XRF.

  20. [Measurement of left atrial and ventricular volumes in real-time 3D echocardiography. Validation by nuclear magnetic resonance

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Qin, J. X.; White, R. D.; Thomas, J. D.

    2001-01-01

    The measurement of the left ventricular ejection fraction is important for the evaluation of cardiomyopathy and depends on the measurement of left ventricular volumes. There are no existing conventional echocardiographic means of measuring the true left atrial and ventricular volumes without mathematical approximations. The aim of this study was to test anew real time 3-dimensional echocardiographic system of calculating left atrial and ventricular volumes in 40 patients after in vitro validation. The volumes of the left atrium and ventricle acquired from real time 3-D echocardiography in the apical view, were calculated in 7 sections parallel to the surface of the probe and compared with atrial (10 patients) and ventricular (30 patients) volumes calculated by nuclear magnetic resonance with the simpson method and with volumes of water in balloons placed in a cistern. Linear regression analysis showed an excellent correlation between the real volume of water in the balloons and volumes given in real time 3-dimensional echocardiography (y = 0.94x + 5.5, r = 0.99, p < 0.001, D = -10 +/- 4.5 ml). A good correlation was observed between real time 3-dimensional echocardiography and nuclear magnetic resonance for the measurement of left atrial and ventricular volumes (y = 0.95x - 10, r = 0.91, p < 0.001, D = -14.8 +/- 19.5 ml and y = 0.87x + 10, r = 0.98, P < 0.001, D = -8.3 +/- 18.7 ml, respectively. The authors conclude that real time three-dimensional echocardiography allows accurate measurement of left heart volumes underlying the clinical potential of this new 3-D method.

  1. [Measurement of left atrial and ventricular volumes in real-time 3D echocardiography. Validation by nuclear magnetic resonance

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Qin, J. X.; White, R. D.; Thomas, J. D.

    2001-01-01

    The measurement of the left ventricular ejection fraction is important for the evaluation of cardiomyopathy and depends on the measurement of left ventricular volumes. There are no existing conventional echocardiographic means of measuring the true left atrial and ventricular volumes without mathematical approximations. The aim of this study was to test anew real time 3-dimensional echocardiographic system of calculating left atrial and ventricular volumes in 40 patients after in vitro validation. The volumes of the left atrium and ventricle acquired from real time 3-D echocardiography in the apical view, were calculated in 7 sections parallel to the surface of the probe and compared with atrial (10 patients) and ventricular (30 patients) volumes calculated by nuclear magnetic resonance with the simpson method and with volumes of water in balloons placed in a cistern. Linear regression analysis showed an excellent correlation between the real volume of water in the balloons and volumes given in real time 3-dimensional echocardiography (y = 0.94x + 5.5, r = 0.99, p < 0.001, D = -10 +/- 4.5 ml). A good correlation was observed between real time 3-dimensional echocardiography and nuclear magnetic resonance for the measurement of left atrial and ventricular volumes (y = 0.95x - 10, r = 0.91, p < 0.001, D = -14.8 +/- 19.5 ml and y = 0.87x + 10, r = 0.98, P < 0.001, D = -8.3 +/- 18.7 ml, respectively. The authors conclude that real time three-dimensional echocardiography allows accurate measurement of left heart volumes underlying the clinical potential of this new 3-D method.

  2. PIV measurements in a real time controlled model wind turbine wake simulator

    NASA Astrophysics Data System (ADS)

    Castillo, R.; Wang, Y.; Monk, T.; Vasquez, S.; Pol, S.; Ren, B.; Swift, A.; Hussain, F.; Westergaard, C. H.

    2016-09-01

    A wind tunnel based “Hyper Accelerated Wind Farm Kinematic-Control Simulator” (HAWKS) is being built at Texas Tech University (TTU) to emulate controlled wind turbine flow physics. The HAWKS model turbine has pitch, yaw and speed controls that could be operated in real time with different power coefficient (Cp) conditions. The purpose of HAWKS is to simulate control strategies, operating at much faster turnaround times. Currently, the fundamental building blocks of the simulator are being tested. A few salient tests results are presented here.

  3. Assessment of offsite, real-time dose measurement systems for emergency situations

    SciTech Connect

    Maeck, W.J.; Hoffman, L.G.; Staples, B.A.; Keller, J.H.

    1982-04-01

    An evaluation is made of the effectiveness of fixed, real-time monitoring systems around nuclear power stations in determining the magnitude of unmonitored releases. The effects of meteorological conditions on the accuracy with which the magnitude of unmonitored releases is determined and the uncertainties inherent in defining these meteorological conditions are discussed. The number and placement of fixed field detectors in a system is discussed, and the data processing equipment required to convert field detector output data into release rate information is described. Cost data relative to the purchase and installation of specific systems are given, as well as the characteristics and information return for a system purchased at an arbitrary cost.

  4. In vivo near-infrared fluorescence imaging of Leishmania amazonensis expressing infrared fluorescence protein (iRFP) for real-time monitoring of cutaneous leishmaniasis in mice.

    PubMed

    Oliveira, Janaina Correia; da Silva, Aline Caroline; Oliveira, Renato Antonio Dos Santos; Pereira, Valéria Rêgo Alves; Gil, Laura Helena Vega Gonzales

    2016-11-01

    The use of Leishmania amazonensis-infected BALB/c mice is an important model for the study of experimental cutaneous leishmaniasis. Here we report the development of a non-invasive method to directly evaluate and measure parasite burden during the course of the infection, based on the near-infrared fluorescence detection of a recombinant L. amazonensis strain. So, we generated a L. amazonensis strain that stably expresses the near-infrared protein (iRFP) gene and compared the maintenance of its vitro and in vivo characteristics, such as fitness, pathogenicity and fluorescence emission. After that, we followed the disease development, as well as the parasite burden in BALB/c mice footpads infected with L. amazonensis-iRFP, by using an in vivo near-infrared fluorescence scanner. In vitro results showed a linear correlation between the fluorescence emission and the number of parasites. The in vivo study showed that the use of iRFP-transfected L. amazonensis enables the monitoring of parasite burden by measuring fluorescence signals. Therefore, this technique can be confidently used to directly monitor parasitic load and infection overtime and could be an excellent tool for in vitro and in vivo screening of anti-leishmanial drugs and vaccine efficiency. This is the first report of the use of the near-infrared fluorescence imaging technique for monitoring in vivo cutaneous leishmaniasis.

  5. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    NASA Astrophysics Data System (ADS)

    Kaser, L.; Karl, T.; Schnitzhofer, R.; Graus, M.; Herdlinger-Blatt, I. S.; DiGangi, J. P.; Sive, B.; Turnipseed, A.; Hornbrook, R. S.; Zheng, W.; Flocke, F. M.; Guenther, A.; Keutsch, F. N.; Apel, E.; Hansel, A.

    2013-03-01

    Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser-Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC) using PTR-(TOF)-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and

  6. Near-Real Time Measurement of Carbonaceous Aerosol Using Microplasma Spectroscopy: Application to Measurement of Carbon Nanomaterials

    PubMed Central

    Zheng, Lina; Kulkarni, Pramod; Birch, M. Eileen; Deye, Gregory; Dionysiou, Dionysios D.

    2017-01-01

    A sensitive, field-portable microplasma spectroscopy method has been developed for real-time measurement of carbon nanomaterials. The method involves microconcentration of aerosol on a microelectrode tip for subsequent analysis for atomic carbon using laser-induced breakdown spectroscopy (LIBS) or spark emission spectroscopy (SES). The spark-induced microplasma was characterized by measuring the excitation temperature (15,000 – 35,000 K), electron density (1.0 × 1017 – 2.2 × 1017 cm−3), and spectral responses as functions of time and interelectrode distance. The system was calibrated and detection limits were determined for total atomic carbon (TAC) using a carbon emission line at 247.856 nm (C I) for various carbonaceous materials including sucrose, EDTA, caffeine, sodium carbonate, carbon black, and carbon nanotubes. The limit of detection for total atomic carbon was 1.61 ng, equivalent to 238 ng m−3 when sampling at 1.5 L min−1 for 5 min. To improve the selectivity for carbon nanomaterials, which consist of elemental carbon (EC), the cathode was heated to 300 °C to reduce the contribution of organic carbon to the total atomic carbon. Measurements of carbon nanotube aerosol at elevated electrode temperature showed improved selectivity to elemental carbon and compared well with the measurements from thermal optical method (NIOSH Method 5040). The study shows that the SES method to be an excellent candidate for development as a low-cost, hand-portable, real-time instrument for measurement of carbonaceous aerosols and nanomaterials. PMID:28638174

  7. Measuring joint cartilage thickness using reflectance spectroscopy non-invasively and in real-time

    NASA Astrophysics Data System (ADS)

    Canpolat, Murat; Denkceken, Tuba; Karagol, Cosar; Aydin, Ahmet T.

    2011-03-01

    Joint cartilage thickness has been estimated using spatially resolved steady-state reflectance spectroscopy noninvasively and in-real time. The system consists of a miniature UV-VIS spectrometer, a halogen tungsten light source, and an optical fiber probe with six 400 um diameter fibers. The first fiber was used to deliver the light to the cartilage and the other five were used to detect back-reflected diffused light. Distances from the detector fibers to the source fiber were 0.8 mm, 1.6 mm, 2.4 mm, 3.2 mm and 4 mm. Spectra of back-reflected diffused light were taken on 40 bovine patella cartilages. The samples were grouped into four; the first group was the control group with undamaged cartilages, in the 2nd, 3rd and 4th groups cartilage thickness was reduced approximately 25%, 50% and 100%, respectively. A correlation between cartilage thicknesses and hemoglobin absorption of light in the wavelength range of 500 nm- 600 nm for source-detector pairs was found. The proposed system with an optical fiber probe less than 4 mm in diameter has the potential for cartilage thickness assessment through an arthroscopy channel in real-time without damaging the cartilage.

  8. Real-time near-infrared (NIR) fluorescent cholangiography in single-site robotic cholecystectomy (SSRC): a single-institutional prospective study.

    PubMed

    Spinoglio, Giuseppe; Priora, Fabio; Bianchi, Paolo Pietro; Lucido, Francesco Saverio; Licciardello, Alessio; Maglione, Valeria; Grosso, Federica; Quarati, Raul; Ravazzoni, Ferruccio; Lenti, Luca Matteo

    2013-06-01

    Bile duct injury is a rare but serious complication of laparoscopic cholecystectomy and the primary cause is misinterpretation of biliary anatomy. This may occur more frequently with a single-incision approach due to difficulties in exposing and visualizing the triangle of Calot. Intraoperative cholangiography was proposed to overcome this problem, but due to multiple issues, it is not used routinely. Indocyanine green (ICG) near-infrared (NIR) fluorescent cholangiography is non invasive and provides real-time biliary images during surgery, which may improve the safety of single-incision cholecystectomy. This study aims to evaluate the efficacy and safety of this technique during single-site robotic cholecystectomy (SSRC). Patients presenting with symptomatic biliary gallstones without suspicion of common bile duct stones underwent SSRC with ICG-NIR fluorescent cholangiography using the da Vinci Fluorescence Imaging Vision System. During patient preparation, 2.5 mg of ICG was injected intravenously. During surgery, the biliary anatomy was imaged in real time, which guided dissection of Calot's triangle. Perioperative outcomes included biliary tree visualizations, operative time, conversion and complications rates, and length of hospital stay. There were 45 cases between July 2011 and January 2012. All procedures were completed successfully; there were no conversions and at least one structure was visualized in each patient. The rates of visualization were 93 % for the cystic duct, 88 % for the common hepatic duct, and 91 % for the common bile duct prior to Calot's dissection; after Calot's dissection, the rates were 97 % for all three ducts. Mean hospital stay was 1.1 days and there were no bile duct injuries or any other major complications. Real-time high-resolution fluorescent imaging to identify the biliary tree anatomy during SSRC using the da Vinci Fluorescence Imaging Vision System was safe and effective.

  9. Interaction of on-site and near real time measured turbidity and enzyme activity in stream water.

    NASA Astrophysics Data System (ADS)

    Stadler, Philipp; Farnleitner, Andreas H.; Zessner, Matthias

    2013-04-01

    On-site and on-line systems that provide an integrated surveillance of physicochemical and microbiological parameters gain significance in water quality monitoring. Particular relating to diffuse pollution from agricultural areas and use-orientated protection of waters the detection of faecal pollution is a fundamental part. For the near real time and on-site detection of microbiological faecal pollution of water, the beta-D- Glucuronidase (GLUC) enzymatic activity has been suggested as a surrogate parameter. Due to possible short measure intervals of three hours, this method has high potential as a water quality monitoring tool. While cultivation based standard determination takes more than one working day (Cabral 2010) the potential advantage of detecting the GLUC activity is the high temporal measuring resolution. Yet, there is still a big gap of knowledge on the sensitivity and specificity concerning the faecal indication capacity of GLUC in relation to standard assays (Cabral 2010). Interference effects of physicochemical parameters on the enzymatic activity respectively fluorescence have been discussed (Molina-Munoz et al. 2007; Tryland and Fiksdal 1998, Biswal et al. 2003). Results from a monitoring of a rivulet in an agricultural catchment in Lower Austria (HOAL - Hydrological Open Air Laboratory) are presented here. The HOAL offers technical resources that allow measurements at high temporal and spatial resolution and to apply various hydrological methods in one catchment. Two automated enzymatic measuring devices (Coliguard, mbOnline, Austria) and physicochemical in-stream measurements are used, as well as in-stream spectroscopy (spectrolyser, s::can, Austria). Accuracy of both enzymatic measuring devices is compared through diverse hydrological and seasonal conditions. Reference analyses by cultivation based determination were performed. Data from Coliguard devices is combined with physicochemical and spectroscopy data to gain information about the

  10. Detection of Ehrlichia canis in canine blood samples by real-time fluorescence resonance energy transfer (FRET) PCR and melting curve analysis.

    PubMed

    Kongklieng, Amornmas; Thanchomnang, Tongjit; Intapan, Pewpan M; Boonmars, Thidarut; Janwan, Penchom; Sanpool, Oranuch; Lulitanond, Viraphong; Taweethavonsawat, Piyanan; Chungpivat, Sudchit; Morakote, Nimit; Maleewong, Wanchai

    2014-09-01

    Ehrlichia canis is a small pleomorphic gram-negative, coccoid, obligatory intracellular bacterium and the cause of canine monocytic ehrlichiosis. A real-time fluorescence resonance energy transfer polymerase chain reaction (real-time FRET PCR) coupled with melting curve analysis was established for detection of E. canis infection in canine blood samples. The VirB9 gene was amplified using one pair of primers and the melting curve analysis was generated by heating the hybridizing probes and amplified products. Eight E. canis-infected dog blood samples were initially identified using the Giemsa staining/microscopic method followed by conventional PCR (cPCR)/Sanger sequencing for confirmation. The sensitivity and specificity of the real-time FRET PCR detection were 87.5% and 100%, respectively and the limit of detection was 6.6 x 10(3) copies of positive E. canis control plasmids. The real-time FRET PCR with melting curve analysis reported here is better than microscopic visualization or cPCR because the method is not affected by the false bias inherent in the microscopic method. Furthermore, many samples can be processed rapidly at the same time. This convenient tool is beneficial as an alternative assay for the epidemiologic study of canine ehrlichiosis as well as for eradication of these organisms in prevention and control programs in endemic areas.

  11. Real time in vivo imaging and measurement of serine protease activity in the mouse hippocampus using a dedicated complementary metal-oxide semiconductor imaging device.

    PubMed

    Ng, David C; Tamura, Hideki; Tokuda, Takashi; Yamamoto, Akio; Matsuo, Masamichi; Nunoshita, Masahiro; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2006-09-30

    The aim of the present study is to demonstrate the application of complementary metal-oxide semiconductor (CMOS) imaging technology for studying the mouse brain. By using a dedicated CMOS image sensor, we have successfully imaged and measured brain serine protease activity in vivo, in real-time, and for an extended period of time. We have developed a biofluorescence imaging device by packaging the CMOS image sensor which enabled on-chip imaging configuration. In this configuration, no optics are required whereby an excitation filter is applied onto the sensor to replace the filter cube block found in conventional fluorescence microscopes. The fully packaged device measures 350 microm thick x 2.7 mm wide, consists of an array of 176 x 144 pixels, and is small enough for measurement inside a single hemisphere of the mouse brain, while still providing sufficient imaging resolution. In the experiment, intraperitoneally injected kainic acid induced upregulation of serine protease activity in the brain. These events were captured in real time by imaging and measuring the fluorescence from a fluorogenic substrate that detected this activity. The entire device, which weighs less than 1% of the body weight of the mouse, holds promise for studying freely moving animals.

  12. Real-Time Studies of Gallium Adsorption and Desorption Kinetics by Grazing-Incidence Small-Angle X-ray Scattering and X-ray Fluorescence

    SciTech Connect

    Wang, Y.; Ozcan, A; Ludwig, K; Bhattacharyya, A

    2008-01-01

    Gallium adsorption and desorption on c-plane sapphire has been studied by real-time grazing incidence small-angle x-ray scattering and x-ray fluorescence as a function of substrate temperature (680-740 C) and Ga flux. The x-ray techniques monitor the surface morphology evolution and amount of Ga on the surface. During deposition, nanodroplets of liquid Ga are observed to form on the surface and coarsen. The growth of droplet size during continuous deposition follows dynamical scaling, in agreement with expectations from theory and simulations which include deposition-induced droplet coalescence. However, observation of continued droplet distance scale coarsening during desorption points to the necessity of including further physical processes in the modeling. The desorption rate at different substrate temperatures gives the activation energy of Ga desorption as 2.7 eV, comparable to measured activation energies for desorption from Ga droplets on other substrates and to the Ga heat of vaporization.

  13. Probe-based Real-time PCR Approaches for Quantitative Measurement of microRNAs

    PubMed Central

    Wong, Wilson; Farr, Ryan; Joglekar, Mugdha; Januszewski, Andrzej; Hardikar, Anandwardhan

    2015-01-01

    Probe-based quantitative PCR (qPCR) is a favoured method for measuring transcript abundance, since it is one of the most sensitive detection methods that provides an accurate and reproducible analysis. Probe-based chemistry offers the least background fluorescence as compared to other (dye-based) chemistries. Presently, there are several platforms available that use probe-based chemistry to quantitate transcript abundance. qPCR in a 96 well plate is the most routinely used method, however only a maximum of 96 samples or miRNAs can be tested in a single run. This is time-consuming and tedious if a large number of samples/miRNAs are to be analyzed. High-throughput probe-based platforms such as microfluidics (e.g. TaqMan Array Card) and nanofluidics arrays (e.g. OpenArray) offer ease to reproducibly and efficiently detect the abundance of multiple microRNAs in a large number of samples in a short time. Here, we demonstrate the experimental setup and protocol for miRNA quantitation from serum or plasma-EDTA samples, using probe-based chemistry and three different platforms (96 well plate, microfluidics and nanofluidics arrays) offering increasing levels of throughput. PMID:25938938

  14. Mirror Langmuir probe: A technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode

    SciTech Connect

    LaBombard, B.; Lyons, L.

    2007-07-15

    A new method for the real-time evaluation of the conditions in a magnetized plasma is described. The technique employs an electronic ''mirror Langmuir probe'' (MLP), constructed from bipolar rf transistors and associated high-bandwidth electronics. Utilizing a three-state bias wave form and active feedback control, the mirror probe's I-V characteristic is continuously adjusted to be a scaled replica of the ''actual'' Langmuir electrode immersed in a plasma. Real-time high-bandwidth measurements of the plasma's electron temperature, ion saturation current, and floating potential can thereby be obtained using only a single electrode. Initial tests of a prototype MLP system are reported, proving the concept. Fast-switching metal-oxide-semiconductor field-effect transistors produce the required three-state voltage bias wave form, completing a full cycle in under 1 {mu}s. Real-time outputs of electron temperature, ion saturation current, and floating potential are demonstrated, which accurately track an independent computation of these values from digitally stored I-V characteristics. The MLP technique represents a significant improvement over existing real-time methods, eliminating the need for multiple electrodes and sampling all three plasma parameters at a single spatial location.

  15. Real time observation and automated measurement of red blood cells agglutination inside a passive microfluidic biochip containing embedded reagents.

    PubMed

    Huet, Maxime; Cubizolles, Myriam; Buhot, Arnaud

    2017-07-15

    The process of agglutination is commonly used for the detection of biomarkers like proteins or viruses. The multiple bindings between micrometer sized particles, either latex beads or red blood cells (RBCs), create aggregates that are easily detectable and give qualitative information about the presence of the biomarkers. In most cases, the detection is made by simple naked-eye observation of agglutinates without any access to the kinetics of agglutination. In this study, we address the development of a real-time time observation of RBCs agglutination. Using ABO blood typing as a proof-of-concept, we developed i) an integrated biological protocol suitable for further use as point-of-care (POC) analysis and ii) two dedicated image processing algorithms for the real-time and quantitative measurement of agglutination. Anti-A or anti-B typing reagents were dried inside the microchannel of a passive microfluidic chip designed to enhance capillary flow. A blood drop deposit at the tip of the biochip established a simple biological protocol. In situ agglutination of autologous RBCs was achieved by means of embedded reagents and real time agglutination process was monitored by video recording. Using a training set of 24 experiments, two real-time indicators based on correlation and variance of gray levels were optimized and then further confirmed on a validation set. 100% correct discrimination between positive and negative agglutinations was performed within less than 2min by measuring real-time evolution of both correlation and variance indicators. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. 3D surface real-time measurement using phase-shifted interference fringe technique for craniofacial identification

    NASA Astrophysics Data System (ADS)

    Levin, Gennady G.; Vishnyakov, Gennady N.; Naumov, Alexey V.; Abramov, Sergey

    1998-03-01

    We offer to use the 3D surface profile real-time measurement using phase-shifted interference fringe projection technique for the cranioficial identification. Our system realizes the profile measurement by projecting interference fringe pattern on the object surface and by observing the deformed fringe pattern at the direction different from the projection. Fringes are formed by a Michelson interferometer with one mirror mounted on a piezoelectric translator. Four steps self- calibration phase-shift method was used.

  17. Real-Time Measurement of Nanotube Resonator Fluctuations in an Electron Microscope.

    PubMed

    Tsioutsios, I; Tavernarakis, A; Osmond, J; Verlot, P; Bachtold, A

    2017-03-08

    Mechanical resonators based on low-dimensional materials provide a unique platform for exploring a broad range of physical phenomena. The mechanical vibrational states are indeed extremely sensitive to charges, spins, photons, and adsorbed masses. However, the roadblock is often the readout of the resonator, because the detection of the vibrational states becomes increasingly difficult for smaller resonators. Here, we report an unprecedentedly sensitive method to detect nanotube resonators with effective masses in the 10(-20) kg range. We use the beam of an electron microscope to resolve the mechanical fluctuations of a nanotube in real-time for the first time. We obtain full access to the thermally driven Brownian motion of the resonator, both in space and time domains. Our results establish the viability of carbon nanotube resonator technology at room temperature and pave the way toward the observation of novel thermodynamics regimes and quantum effects in nanomechanics.

  18. Real-Time Measurement of Nanotube Resonator Fluctuations in an Electron Microscope

    NASA Astrophysics Data System (ADS)

    Tsioutsios, I.; Tavernarakis, A.; Osmond, J.; Verlot, P.; Bachtold, A.

    2017-03-01

    Mechanical resonators based on low-dimensional materials provide a unique platform for exploring a broad range of physical phenomena. The mechanical vibrational states are indeed extremely sensitive to charges, spins, photons, and adsorbed masses. However, the roadblock is often the readout of the resonator, since the detection of the vibrational states becomes increasingly difficult for smaller resonators. Here, we report an unprecedentedly sensitive method to detect nanotube resonators with effective masses in the 10^-20 kg range. We use the beam of an electron microscope to resolve the mechanical fluctuations of a nanotube in real-time for the first time. We obtain full access to the thermally-driven Brownian motion of the resonator, both in space and time domains. Our results establish the viability of carbon nanotube resonator technology at room temperature and pave the way towards the observation of novel thermodynamics regimes and quantum effects in nano-mechanics.

  19. Real-Time Measurement of Nanotube Resonator Fluctuations in an Electron Microscope

    PubMed Central

    2017-01-01

    Mechanical resonators based on low-dimensional materials provide a unique platform for exploring a broad range of physical phenomena. The mechanical vibrational states are indeed extremely sensitive to charges, spins, photons, and adsorbed masses. However, the roadblock is often the readout of the resonator, because the detection of the vibrational states becomes increasingly difficult for smaller resonators. Here, we report an unprecedentedly sensitive method to detect nanotube resonators with effective masses in the 10–20 kg range. We use the beam of an electron microscope to resolve the mechanical fluctuations of a nanotube in real-time for the first time. We obtain full access to the thermally driven Brownian motion of the resonator, both in space and time domains. Our results establish the viability of carbon nanotube resonator technology at room temperature and pave the way toward the observation of novel thermodynamics regimes and quantum effects in nanomechanics. PMID:28186773

  20. Measurement and analysis of workload effects on fault latency in real-time systems

    NASA Technical Reports Server (NTRS)

    Woodbury, Michael H.; Shin, Kang G.

    1990-01-01

    The authors demonstrate the need to address fault latency in highly reliable real-time control computer systems. It is noted that the effectiveness of all known recovery mechanisms is greatly reduced in the presence of multiple latent faults. The presence of multiple latent faults increases the possibility of multiple errors, which could result in coverage failure. The authors present experimental evidence indicating that the duration of fault latency is dependent on workload. A synthetic workload generator is used to vary the workload, and a hardware fault injector is applied to inject transient faults of varying durations. This method makes it possible to derive the distribution of fault latency duration. Experimental results obtained from the fault-tolerant multiprocessor at the NASA Airlab are presented and discussed.

  1. Measurement and analysis of workload effects on fault latency in real-time systems

    NASA Technical Reports Server (NTRS)

    Woodbury, Michael H.; Shin, Kang G.

    1990-01-01

    The authors demonstrate the need to address fault latency in highly reliable real-time control computer systems. It is noted that the effectiveness of all known recovery mechanisms is greatly reduced in the presence of multiple latent faults. The presence of multiple latent faults increases the possibility of multiple errors, which could result in coverage failure. The authors present experimental evidence indicating that the duration of fault latency is dependent on workload. A synthetic workload generator is used to vary the workload, and a hardware fault injector is applied to inject transient faults of varying durations. This method makes it possible to derive the distribution of fault latency duration. Experimental results obtained from the fault-tolerant multiprocessor at the NASA Airlab are presented and discussed.

  2. Real-time measurements of membrane surface dynamics on macrophages and the phagocytosis of Leishmania parasites.

    PubMed

    Coelho Neto, José; Agero, Ubirajara; Oliveira, Diogo C P; Gazzinelli, Ricardo T; Mesquita, Oscar N

    2005-02-15

    Defocusing microscopy was used for real-time observation and quantification of membrane surface dynamics in murine bone marrow macrophages. Small random membrane fluctuations (SRMF), possibly metabolic driven, were detected uniformly over all membrane surface. Morphological and dynamical parameters of ruffles, such as shape, dimensions, and velocity of propagation, were analyzed. Optical tweezers were used to promote phagocytosis of single Leishmania amazonensis amastigotes by selected macrophages. Analysis of ruffling activity on the macrophages before and during phagocytosis of the parasites indicated that increased ruffling response near forming phagosomes, most likely induced by the parasite, accelerates phagocytosis. The effects of temperature decrease on the dynamics of membrane surface fluctuations and on the phagocytosis of parasites were used to determine the overall activation energies involved in these processes. The values obtained support the existence of strong correlation between membrane motility and phagocytic capacity.

  3. A real-time measure of cavitation induced tissue disruption by ultrasound imaging backscatter reduction.

    PubMed

    Hall, Timothy L; Fowlkes, J Brian; Cain, Charles A

    2007-03-01

    A feedback method for obtaining real-time information on the mechanical disruption of tissue through ultrasound cavitation is presented. This method is based on a substantial reduction in ultrasound imaging backscatter from the target volume as the tissue structure is broken down. Ex-vivo samples of porcine liver were exposed to successive high-intensity ultrasound pulses at a low duty cycle to induce mechanical disruption of tissue parenchyma through cavitation (referred to as histotripsy). At the conclusion of treatment, B-scan imaging backscatter was observed to have decreased by 22.4 +/- 2.3 dB in the target location. Treated samples of tissue were found to contain disrupted tissue corresponding to the imaged hypoechoic volume with no remaining discernable structure and a sharp boundary. The observed, substantial backscatter reduction may be an effective feedback mechanism for assessing treatment efficacy in ultrasound surgery using pulsed ultrasound to create cavitation.

  4. A luminescent assay for real-time measurements of receptor endocytosis in living cells.

    PubMed

    Robers, Matthew B; Binkowski, Brock F; Cong, Mei; Zimprich, Chad; Corona, Cesear; McDougall, Mark; Otto, George; Eggers, Christopher T; Hartnett, Jim; Machleidt, Thomas; Fan, Frank; Wood, Keith V

    2015-11-15

    Ligand-mediated endocytosis is a key autoregulatory mechanism governing the duration and intensity of signals emanating from cell surface receptors. Due to the mechanistic complexity of endocytosis and its emerging relevance in disease, simple methods capable of tracking this dynamic process in cells have become increasingly desirable. We have developed a bioluminescent reporter technology for real-time analysis of ligand-mediated receptor endocytosis using genetic fusions of NanoLuc luciferase with various G-protein-coupled receptors (GPCRs). This method is compatible with standard microplate formats, which should decrease work flows for high-throughput screens. This article also describes the application of this technology to endocytosis of epidermal growth factor receptor (EGFR), demonstrating potential applicability of the method beyond GPCRs.

  5. Breaking Out of the Lab: Measuring Real-Time Responses to Televised Political Content in Real-World Settings.

    PubMed

    Maier, Jürgen; Hampe, J Felix; Jahn, Nico

    2016-01-01

    Real-time response (RTR) measurement is an important technique for analyzing human processing of electronic media stimuli. Although it has been demonstrated that RTR data are reliable and internally valid, some argue that they lack external validity. The reason for this is that RTR measurement is restricted to a laboratory environment due to its technical requirements. This paper introduces a smartphone app that 1) captures real-time responses using the dial technique and 2) provides a solution for one of the most important problems in RTR measurement, the (automatic) synchronization of RTR data. In addition, it explores the reliability and validity of mobile RTR measurement by comparing the real-time reactions of two samples of young and well-educated voters to the 2013 German televised debate. Whereas the first sample participated in a classical laboratory study, the second sample was equipped with our mobile RTR system and watched the debate at home. Results indicate that the mobile RTR system yields similar results to the lab-based RTR measurement, providing evidence that laboratory studies using RTR are externally valid. In particular, the argument that the artificial reception situation creates artificial results has to be questioned. In addition, we conclude that RTR measurement outside the lab is possible. Hence, mobile RTR opens the door for large-scale studies to better understand the processing and impact of electronic media content.

  6. Real-time interferometric monitoring and measuring of photopolymerization based stereolithographic additive manufacturing process: sensor model and algorithm

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Rosen, D. W.

    2017-01-01

    As additive manufacturing is poised for growth and innovations, it faces barriers of lack of in-process metrology and control to advance into wider industry applications. The exposure controlled projection lithography (ECPL) is a layerless mask-projection stereolithographic additive manufacturing process, in which parts are fabricated from photopolymers on a stationary transparent substrate. To improve the process accuracy with closed-loop control for ECPL, this paper develops an interferometric curing monitoring and measuring (ICM&M) method which addresses the sensor modeling and algorithms issues. A physical sensor model for ICM&M is derived based on interference optics utilizing the concept of instantaneous frequency. The associated calibration procedure is outlined for ICM&M measurement accuracy. To solve the sensor model, particularly in real time, an online evolutionary parameter estimation algorithm is developed adopting moving horizon exponentially weighted Fourier curve fitting and numerical integration. As a preliminary validation, simulated real-time measurement by offline analysis of a video of interferograms acquired in the ECPL process is presented. The agreement between the cured height estimated by ICM&M and that measured by microscope indicates that the measurement principle is promising as real-time metrology for global measurement and control of the ECPL process.

  7. Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time.

    PubMed

    May, Robert K; Evans, Michael J; Zhong, Shuncong; Warr, Ian; Gladden, Lynn F; Shen, Yaochun; Zeitler, J Axel

    2011-04-01

    We present a new in-line measurement technique to determine the coating thickness of individual pharmaceutical tablets during film coating in a pan coating unit using pulsed terahertz technology. Results of these real-time terahertz measurements acquired during a production scale coating run are validated using both off-line high-resolution terahertz pulsed imaging of the whole dosage form as well as weight-gain measurements made on sample tablets removed at discrete time intervals during the process run. The terahertz measurements provide a direct method of determining the coating thickness, and no chemometric calibration models are required for the quantification. The results, and their repeatability, demonstrate that real-time monitoring of pharmaceutical tablet coating is not only possible but also provides substantially more information of the coating quality than the standard quality control method. Rather than providing the average coating thickness of a large number of tablets, the terahertz sensor provides the thickness of up to 100 individual tablet coatings per minute. Using this information, the operator can get additional information about the thickness distribution in the coating pan and adjust the process accordingly. At present, a minimum coating thickness of 40 μm is required to determine the coating thickness. The technique is applicable for coatings up to 1 mm in thickness. Within that range, it provides thickness measurements of sub-micron resolution. Terahertz in-line coating process measurements show considerable potential for applications in real-time release, process analytical technology and quality by design.

  8. Design study of optical fiber F-P sensing system for bio-tissue temperature real-time measurement

    NASA Astrophysics Data System (ADS)

    Ning, Shan; Heng, Guo

    2011-11-01

    The measurement theory of optical fiber F-P temperature sensor is analyzed according to difficult problem that temperature is real-time measured in the study of thermal interaction between laser and bio-tissue. The model of temperature and strain is established. The work point stabilization method of optical fiber F-P sensor is studied. The optimal model of low fineness optical fiber F-P sensing system is established based on the technique of dual optical wavelength stabilization. The experimental device of real-time measurement temperature is build. The experimental results show that the sensor has higher measurement precision and small bulk. And the hurt is little for bio-tissue. It can be used to the real-time temperature measurement of bio-tissue efficiency. When the sensor is used to the continuum temperature measurement, the maximum absoluteness error is 0.63°C and the maximum relatively error is 1.4%. When the sensor worked half hour, the maximum cumulate error is 1.3%.

  9. Dielectric measurement method for real-time monitoring of initial hardening of backfill materials used for underground construction

    NASA Astrophysics Data System (ADS)

    Karlovšek, Jurij; Schwing, Moritz; Chen, Zhen; Wagner, Norman; Williams, David J.; Scheuermann, Alexander

    2016-04-01

    The broadband dielectric measurement method based on the vector network analysis technique, in combination with an open-ended coaxial probe, was applied to the determination of the dielectric relaxation behaviour of one- and two-component backfilling grout materials in the frequency range from 40 MHz to 2 GHz. The cement hydration process and the gelling of commercial grouts was monitored in real-time to investigate the application of non-destructive testing methods in the tunnelling industry. It was found that the time-dependent dielectric relaxation behaviour can accurately reveal the different stages of the hydration process and delineate the start of gel hardening. These measurement results demonstrate the practicability of the real-time dielectric measurement method to determine the broadband dielectric parameters of conventional backfill materials used in underground construction to determine construction integrity using non-destructive testing methods.

  10. Recent development status of the quasi real-time crustal deformation monitoring based on the onshore real-time GNSS data and offshore GNSS/Acoustic measurement in Japan

    NASA Astrophysics Data System (ADS)

    Ohta, Y.; Hino, R.; Kido, M.; Imano, M.; Kawamoto, S.; Sato, Y.; Takahashi, N.

    2015-12-01

    The 2011 Tohoku-Oki earthquake and its associated tsunami clearly showed the need for an accurate tsunami early warning system. Real-time GNSS data have an advantage over the short-time seismograms because robust estimations of location and dimension of coseismic faults can be derived from spatial patterns of permanent coseismic displacement measured by real-time GNSS data. Based on these backgrounds, GSI and Tohoku University has been developed the real-time GNSS analysis system. GSI named this system as REGARD (real-time GEONET Analysis for Rapid Deformation Monitoring), which consists three subsystems: (1) Real-time GPS positioning for all of the GEONET site in every one second, (2) automated extraction of displacement fields due to the large earthquake, and (3) automated estimation of Mw by an approximated single rectangular fault or slip distribution in the assumed plated interface. In contrast, lack of the geodetic observation in the offshore region should cause the resolution degrading of the coseismic fault estimation or coseismic slip distribution. In fact, GNSS/Acoustic (GNSS/A) geodetic measurements have revealed the unexpectedly large extent of the 2011 Tohoku-Oki earthquake rupture near the Japan Trench (e.g., Kido et al. 2011). To reveal the earthquake mechanisms and occurrence, as well as co- and post-seismic behaviours, the observation of seafloor crustal deformation in the offshore region is very important. Thus, we are now developing a continuous horizontal and vertical crustal deformation and tsunami observation system based on the moored buoy by a slack cable. This system measures the horizontal and vertical coseismic displacement just after the large earthquake deduced from GNSS/Acoustic measurement and ocean bottom pressure measurement, respectively (Takahashi et al., 2014, 2015). We will introduce the current development status of the quasi real-time crustal deformation monitoring deduced from these onshore and offshore systems based on the