WorldWideScience

Sample records for malfunctioning fluorescent lighting

  1. Simulation of rectifier voltage malfunction on OWECS, four-level converter, HVDC light link: Smart grid context tool

    International Nuclear Information System (INIS)

    Seixas, M.; Melício, R.; Mendes, V.M.F.

    2015-01-01

    Highlights: • Floating offshore wind turbine in deep water. • DC link and voltage malfunction. • Converter topology considered is four-level. • Controllers are based on fractional-order. • Smart grid context. - Abstract: This paper presents a model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase. The offshore wind system model comprises a variable-speed wind turbine supported on a floating platform, equipped with a permanent magnet synchronous generator using full-power four-level neutral point clamped converter. The link from the offshore floating platform to the onshore electrical grid is done through a light high voltage direct current submarine cable. The drive train is modeled by a three-mass model. Considerations about the smart grid context are offered for the use of the model in such a context. The rectifier voltage malfunction domino effect is presented as a case study to show capabilities of the model

  2. Fluorescence lifetime imaging using light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Gordon T; Munro, Ian; Poher, Vincent; French, Paul M W; Neil, Mark A A [Blackett Laboratory, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Elson, Daniel S [Institute of Biomedical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Hares, Jonathan D [Kentech Instruments Ltd, Unit 9, Hall Farm Workshops, South Moreton, Didcot, Oxfordshire, OX11 9AG (United Kingdom)], E-mail: gordon.kennedy@imperial.ac.uk

    2008-05-07

    We demonstrate flexible use of low cost, high-power light emitting diodes as illumination sources for fluorescence lifetime imaging (FLIM). Both time-domain and frequency-domain techniques have been implemented at wavelengths spanning the range 450-640 nm. Additionally, we demonstrate optically sectioned fluorescence lifetime imaging by combining structured illumination with frequency-domain FLIM.

  3. Sustainable LED Fluorescent Light Replacement Technology

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-09-30

    Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life: Environmental Impact Review – Designs are comparable

  4. Fluorescent lighting with aluminum nitride phosphors

    Science.gov (United States)

    Cherepy, Nerine J.; Payne, Stephen A.; Seeley, Zachary M.; Srivastava, Alok M.

    2016-05-10

    A fluorescent lamp includes a glass envelope; at least two electrodes connected to the glass envelope; mercury vapor and an inert gas within the glass envelope; and a phosphor within the glass envelope, wherein the phosphor blend includes aluminum nitride. The phosphor may be a wurtzite (hexagonal) crystalline structure Al.sub.(1-x)M.sub.xN phosphor, where M may be drawn from beryllium, magnesium, calcium, strontium, barium, zinc, scandium, yttrium, lanthanum, cerium, praseodymium, europium, gadolinium, terbium, ytterbium, bismuth, manganese, silicon, germanium, tin, boron, or gallium is synthesized to include dopants to control its luminescence under ultraviolet excitation. The disclosed Al.sub.(1-x)M.sub.xN:Mn phosphor provides bright orange-red emission, comparable in efficiency and spectrum to that of the standard orange-red phosphor used in fluorescent lighting, Y.sub.2O.sub.3:Eu. Furthermore, it offers excellent lumen maintenance in a fluorescent lamp, and does not utilize "critical rare earths," minimizing sensitivity to fluctuating market prices for the rare earth elements.

  5. Fluorescence image excited by a scanning UV-LED light

    Science.gov (United States)

    Tsai, Hsin-Yi; Chen, Yi-Ju; Huang, Kuo-Cheng

    2013-03-01

    An optical scanning system using UV-LED light to induced fluorescence technology can enhance a fluorescence image significantly in a short period. It has several advantages such as lower power consumption, no scattering effect in skins, and multilayer images can be obtained to analyze skin disease. From the experiment results, the light intensity increases with increase spot size and decrease scanning speed, but the image resolution is oppositely. Moreover, the system could be widely used in clinical diagnosis and photodynamic therapy for skin disease because even the irradiated time of fluorescence substance is short but it will provide accurately positioning of fluorescence object.

  6. Light extraction efficiency enhancement for fluorescent SiC based white light-emitting diodes

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    Fluorescent SiC based white light-emitting diodes(LEDs) light source, as an innovative energy-efficient light source, would even have longer lifetime, better light quality and eliminated blue-tone effect, compared to the current phosphor based white LED light source. In this paper, the yellow...

  7. Light emission from compound eye with conformal fluorescent coating

    Science.gov (United States)

    Martín-Palma, Raúl J.; Miller, Amy E.; Pulsifer, Drew P.; Lakhtakia, Akhlesh

    2015-03-01

    Compound eyes of insects are attractive biological systems for engineered biomimicry as artificial sources of light, given their characteristic wide angular field of view. A blowfly eye was coated with a thin conformal fluorescent film, with the aim of achieving wide field-of-view emission. Experimental results showed that the coated eye emitted visible light and that the intensity showed a weaker angular dependence than a fluorescent thin film deposited on a flat surface.

  8. Fundamentals of fluorescence microscopy exploring life with light

    CERN Document Server

    Mondal, Partha Pratim

    2014-01-01

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

  9. Integrated ultrasonic particle positioning and low excitation light fluorescence imaging

    International Nuclear Information System (INIS)

    Bernassau, A. L.; Al-Rawhani, M.; Beeley, J.; Cumming, D. R. S.

    2013-01-01

    A compact hybrid system has been developed to position and detect fluorescent micro-particles by combining a Single Photon Avalanche Diode (SPAD) imager with an acoustic manipulator. The detector comprises a SPAD array, light-emitting diode (LED), lenses, and optical filters. The acoustic device is formed of multiple transducers surrounding an octagonal cavity. By stimulating pairs of transducers simultaneously, an acoustic landscape is created causing fluorescent micro-particles to agglomerate into lines. The fluorescent pattern is excited by a low power LED and detected by the SPAD imager. Our technique combines particle manipulation and visualization in a compact, low power, portable setup

  10. Hybrid fluorescent layer emitting polarized light

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammadimasoudi

    2017-07-01

    Full Text Available Semiconductor nanorods have anisotropic absorption and emission properties. In this work a hybrid luminescent layer is produced based on a mixture of CdSe/CdS nanorods dispersed in a liquid crystal that is aligned by an electric field and polymerized by UV illumination. The film emits light with polarization ratio 0.6 (polarization contrast 4:1. Clusters of nanorods in liquid crystal can be avoided by applying an AC electric field with sufficient amplitude. This method can be made compatible with large-scale processing on flexible transparent substrates. Thin polarized light emitters can be used in LCD backlights or solar concentrators to increase the efficiency.

  11. White organic light-emitting diodes with fluorescent tube efficiency.

    Science.gov (United States)

    Reineke, Sebastian; Lindner, Frank; Schwartz, Gregor; Seidler, Nico; Walzer, Karsten; Lüssem, Björn; Leo, Karl

    2009-05-14

    The development of white organic light-emitting diodes (OLEDs) holds great promise for the production of highly efficient large-area light sources. High internal quantum efficiencies for the conversion of electrical energy to light have been realized. Nevertheless, the overall device power efficiencies are still considerably below the 60-70 lumens per watt of fluorescent tubes, which is the current benchmark for novel light sources. Although some reports about highly power-efficient white OLEDs exist, details about structure and the measurement conditions of these structures have not been fully disclosed: the highest power efficiency reported in the scientific literature is 44 lm W(-1) (ref. 7). Here we report an improved OLED structure which reaches fluorescent tube efficiency. By combining a carefully chosen emitter layer with high-refractive-index substrates, and using a periodic outcoupling structure, we achieve a device power efficiency of 90 lm W(-1) at 1,000 candelas per square metre. This efficiency has the potential to be raised to 124 lm W(-1) if the light outcoupling can be further improved. Besides approaching internal quantum efficiency values of one, we have also focused on reducing energetic and ohmic losses that occur during electron-photon conversion. We anticipate that our results will be a starting point for further research, leading to white OLEDs having efficiencies beyond 100 lm W(-1). This could make white-light OLEDs, with their soft area light and high colour-rendering qualities, the light sources of choice for the future.

  12. Light sheet-based fluorescence microscopy (LSFM) reduces phototoxic effects and provides new means for the modern life sciences

    Science.gov (United States)

    Pampaloni, Francesco; Ansari, Nari; Girard, Philippe; Stelzer, Ernst H. K.

    2011-07-01

    Most optical technologies are applied to flat, basically two-dimensional cellular systems. However, physiological meaningful information relies on the morphology, the mechanical properties and the biochemistry of a cell's context. A cell requires the complex three-dimensional relationship to other cells. However, the observation of multi-cellular biological specimens remains a challenge. Specimens scatter and absorb light, thus, the delivery of the probing light and the collection of the signal light become inefficient; many endogenous biochemical compounds also absorb light and suffer degradation of some sort (photo-toxicity), which induces malfunction of a specimen. In conventional and confocal fluorescence microscopy, whenever a single plane, the entire specimen is illuminated. Recording stacks of images along the optical Z-axis thus illuminates the entire specimen once for each plane. Hence, cells are illuminated 10-20 and fish 100-300 times more often than they are observed. This can be avoided by changing the optical arrangement. The basic idea is to use light sheets, which are fed into the specimen from the side and overlap with the focal plane of a wide-field fluorescence microscope. In contrast to an epi-fluorescence arrangement, such an azimuthal fluorescence arrangement uses two independently operated lenses for illumination and detection. Optical sectioning and no photo-toxic damage or photo-bleaching outside a small volume close to the focal plane are intrinsic properties. Light sheet-based fluorescence microscopy (LSFM) takes advantage of modern camera technologies. LSFM can be operated with laser cutters and for fluorescence correlation spectroscopy. During the last few years, LSFM was used to record zebrafish development from the early 32-cell stage until late neurulation with sub-cellular resolution and short sampling periods (60-90 sec/stack). The recording speed was five 4-Megapixel large frames/sec with a dynamic range of 12-14 bit. We followed

  13. The instantaneous light-intensity function of a fluorescent lamp

    Energy Technology Data Exchange (ETDEWEB)

    Gluskin, Emanuel [Holon Institute of Technology, 52 Golomb St., Holon 58102 (Israel): Electrical Engineering Department, Ben-Gurion University, Beer-Sheva 84105 (Israel)]. E-mail: gluskin@ee.bgu.ac.il; Topalis, Frangiskos V. [Technical University of Athens, School of Electrical and Computer Engineering, 9 Iroon Politechniou St., 15780 Athens (Greece); Kateri, Ifigenia [Technical University of Athens, School of Electrical and Computer Engineering, 9 Iroon Politechniou St., 15780 Athens (Greece); Bisketzis, Nikolas [Technical University of Athens, School of Electrical and Computer Engineering, 9 Iroon Politechniou St., 15780 Athens (Greece)

    2006-05-08

    Using some simple physics and 'system' considerations, the instantaneous light intensity function {psi}(t) of a fluorescent lamp fed via a regular ballast from the 50-60 Hz line is argued to be {psi}(t)={psi}{sub min}+bp(t), where p(t) is the instantaneous power function of the lamp, and b is a constant, and experiment confirms this formula well. The main frequency of {psi}(t), the very significant singularity of its waveform, and the relative intensity of the ripple, i.e., the depth of the modulation, are the focus. The results are important for research into the vision problem that some humans (autistic, but others, too) experience regarding fluorescent light. The inertia of the processes in the lamp which are responsible for the light emission, provides some nonzero emission at the instants when p(t) has zeros. The smaller the volume of the tube and the mass of the gas are, the more weakly the inertia of the processes is expressed, and the relatively smaller is {psi}{sub min}. However, it should be very difficult to theoretically obtain {psi}(t), in particular {psi}{sub min}, from the very complicated physics of the low-pressure discharge in the tube. We conclude that {psi}{sub min} has to be connected with the (also easily measured) lamp's inductance. The work should attract more attention of the physicists to the properties of the common fluorescent lamps. escent lamps.

  14. Light emitting diode excitation emission matrix fluorescence spectroscopy.

    Science.gov (United States)

    Hart, Sean J; JiJi, Renée D

    2002-12-01

    An excitation emission matrix (EEM) fluorescence instrument has been developed using a linear array of light emitting diodes (LED). The wavelengths covered extend from the upper UV through the visible spectrum: 370-640 nm. Using an LED array to excite fluorescence emission at multiple excitation wavelengths is a low-cost alternative to an expensive high power lamp and imaging spectrograph. The LED-EEM system is a departure from other EEM spectroscopy systems in that LEDs often have broad excitation ranges which may overlap with neighboring channels. The LED array can be considered a hybrid between a spectroscopic and sensor system, as the broad LED excitation range produces a partially selective optical measurement. The instrument has been tested and characterized using fluorescent dyes: limits of detection (LOD) for 9,10-bis(phenylethynyl)-anthracene and rhodamine B were in the mid parts-per-trillion range; detection limits for the other compounds were in the low parts-per-billion range (LED-EEMs were analyzed using parallel factor analysis (PARAFAC), which allowed the mathematical resolution of the individual contributions of the mono- and dianion fluorescein tautomers a priori. Correct identification and quantitation of six fluorescent dyes in two to six component mixtures (concentrations between 12.5 and 500 ppb) has been achieved with root mean squared errors of prediction (RMSEP) of less than 4.0 ppb for all components.

  15. Blue fluorescent organic light emitting diodes with multilayered graphene anode

    International Nuclear Information System (INIS)

    Hwang, Joohyun; Choi, Hong Kyw; Moon, Jaehyun; Shin, Jin-Wook; Joo, Chul Woong; Han, Jun-Han; Cho, Doo-Hee; Huh, Jin Woo; Choi, Sung-Yool; Lee, Jeong-Ik; Chu, Hye Yong

    2012-01-01

    As an innovative anode for organic light emitting devices (OLEDs), we have investigated graphene films. Graphene has importance due to its huge potential in flexible OLED applications. In this work, graphene films have been catalytically grown and transferred to the glass substrate for OLED fabrications. We have successfully fabricated 2 mm × 2 mm device area blue fluorescent OLEDs with graphene anodes which showed 2.1% of external quantum efficiency at 1000 cd/m 2 . This is the highest value reported among fluorescent OLEDs using graphene anodes. Oxygen plasma treatment on graphene has been found to improve hole injections in low voltage regime, which has been interpreted as oxygen plasma induced work function modification. However, plasma treatment also increases the sheet resistance of graphene, limiting the maximum luminance. In summary, our works demonstrate the practical possibility of graphene as an anode material for OLEDs and suggest a processing route which can be applied to various graphene related devices.

  16. Remote fluorescent penetrant system sheds new light on cracking

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A remotely operated fluorescent penetrant inspection system developed in Sweden has successfully identified very small cracks -less than 2mm in length and less than 0.2mm in depth. The method, which is being patented, is applicable to all sizes of tubing, as well as other types of flat or curved surfaces. The system consists of a specially designed probe attached to a flexible hose. The probe is positioned by a remotely operated pusher-puller, which can be attached to any kind of robot. The pusher-puller is equipped with electrical motors and encoders for exact positioning at any given location. The hose is attached to a pump and valve unit remote from the item under test, located in the same area as the control equipment for the pusher-puller and the robot. Once the probe has been positioned in the area of interest, it is able to apply fluorescent penetrant test fluid remotely to the surface under test, using a system of inflatable seals. A fluorescent print is made on the probe head, which is then removed from the tube and another probe head fitted for testing of the next tube. Testing takes about 10 minutes per tube. To take measurements, a photograph of the probe head can be taken under ultraviolet light. Manual transfer of the fluorescent print under ultraviolet light to a transparent plastic sheet, temporarily wrapped around the probe head, is also done. The plastic sheet is then unfolded and copied in a normal photocopying machine, and a permanent record thus created. (author)

  17. Fluorescent-light-induced lethality and DNA repair in normal and xeroderma pigmentosum fibroblasts

    International Nuclear Information System (INIS)

    Ritter, M.A.; Williams, J.R.

    1981-01-01

    Cell survival and induction of endonuclease-sensitive sites in DNA were measured in human fibroblast cells exposed to fluorescent light or germicidal ultraviolet light. Cells from a xeroderma pigmentosum patient were hypersensitive to cell killing by fluorescent light, although less so than for germicidal ultraviolet light. Xeroderma pigmentosum cells were deficient in the removal of fluorescent light-induced endonuclease sites that are probably pyrimidine dimers, and both the xeroderma pigmentosum and normal cells removed these sites with kinetics indistinguishable from those for ultraviolet light-induced sites. A comparison of fluorescent with ultraviolet light data demonstrates that there are markedly fewer pyrimidine dimers per lethal event for fluorescent than for ultraviolet light, suggesting a major role for non-dimer damage in fluorescent lethality. (Auth.)

  18. Ultrafast fluorescence of photosynthetic crystals and light-harvesting complexes

    NARCIS (Netherlands)

    Oort, van B.F.

    2008-01-01

    This thesis focuses on the study of photosynthetic pigment protein complexes using time resolved fluorescence techniques. Fluorescence spectroscopy often requires attaching fluorescent labels to the proteins under investigation. With photosynthetic proteins this is not necessary, because these

  19. Evaluation of a fluorescent light densitometer for radiochromic film analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cheung Tsang; Butson, M.J. E-mail: butsonm@iahs.nsw.gov.au; Yu, P.K.N

    2002-01-01

    Radiochromic film dosimetry used in high energy X-ray detection has been evaluated using a VIDAR VXR-12 digitiser for accuracy and results are compared to other densitometers. The VIDAR scanner uses a broad band fluorescent light source which however, produces a negligible ultraviolet reaction effect on the radiochromic film with an estimated equivalent dose of 0.25 cGy darkening per scan to MD-55-2 film. By varying the exposure setting on the scanner, more accurate information can be obtained using radiochromic film within a certain optical density range. Over the range of 0-20 Gy, the scanner can accurately measure dose with a standard deviation of 1.8% calculated between the measured values and a polynomial fit to data. The VIDAR scanner is shown to be a suitable densitometer for radiochromic film.

  20. Evaluation of a fluorescent light densitometer for radiochromic film analysis

    International Nuclear Information System (INIS)

    Cheung Tsang; Butson, M.J.; Yu, P.K.N.

    2002-01-01

    Radiochromic film dosimetry used in high energy X-ray detection has been evaluated using a VIDAR VXR-12 digitiser for accuracy and results are compared to other densitometers. The VIDAR scanner uses a broad band fluorescent light source which however, produces a negligible ultraviolet reaction effect on the radiochromic film with an estimated equivalent dose of 0.25 cGy darkening per scan to MD-55-2 film. By varying the exposure setting on the scanner, more accurate information can be obtained using radiochromic film within a certain optical density range. Over the range of 0-20 Gy, the scanner can accurately measure dose with a standard deviation of 1.8% calculated between the measured values and a polynomial fit to data. The VIDAR scanner is shown to be a suitable densitometer for radiochromic film

  1. A light diet for a giant appetite: An assessment of China's fluorescent lamp standard

    International Nuclear Information System (INIS)

    Lin Jiang

    2005-01-01

    Lighting has been one of the fastest growing electric end uses in China over the last 20 years, with an average annual growth rate of 14%. Fluorescent lighting provides a significant portion of China's lighting needs. In 1998, China produced 680 million fluorescent lamps, of which 420 million were linear fluorescent lamps of various diameters (T8-T12). There are substantial variations both in energy efficiency and lighting performance among locally produced fluorescent lamps. Such variations present a perfect opportunity for policy intervention through energy efficiency standards to promote the adoption of more efficient fluorescent lamps in China. This paper analyzes China's 2003 minimum efficiency standard for linear fluorescent lamps and presents an assessment of its likely impacts on China's lighting energy consumption and greenhouse gas emissions

  2. Ultrafast fluorescence of photosynthetic crystals and light-harvesting complexes

    OpenAIRE

    Oort, van, B.F.

    2008-01-01

    This thesis focuses on the study of photosynthetic pigment protein complexes using time resolved fluorescence techniques. Fluorescence spectroscopy often requires attaching fluorescent labels to the proteins under investigation. With photosynthetic proteins this is not necessary, because these proteins contain fluorescent pigments. Each pigment’s fluorescence is influenced by its environment, and thereby may provide information on structure and dynamics of pigment protein complexes in vitro a...

  3. Startup, Shutdown, & Malfunction (SSM) Emissions

    Science.gov (United States)

    EPA issued a final action to ensure states have plans in place that are fully consistent with the Clean Air Act and recent court decisions concerning startup, shutdown and malfunction (SSM) operations.

  4. Green Fluorescent Organic Light Emitting Device with High Luminance

    Directory of Open Access Journals (Sweden)

    Ning YANG

    2014-06-01

    Full Text Available In this work, we fabricated the small molecule green fluorescent bottom-emission organic light emitting device (OLED with the configuration of glass substrate/indium tin oxide (ITO/Copper Phthalocyanine (CuPc 25 nm/ N,N’-di(naphthalen-1-yl-N,N’-diphenyl-benzidine (NPB 45 nm/ tris(8-hydroxyquinoline aluminium (Alq3 60 nm/ Lithium fluoride (LiF 1 nm/Aluminum (Al 100 nm where CuPc and NPB are the hole injection layer and the hole transport layer, respectively. CuPc is introduced in this device to improve carrier injection and efficiency. The experimental results indicated that the turn-on voltage is 2.8 V with a maximum luminance of 23510 cd/m2 at 12 V. The maximum current efficiency and power efficiency are 4.8 cd/A at 100 cd/m2 and 4.2 lm/W at 3 V, respectively. The peak of electroluminance (EL spectrum locates at 530 nm which is typical emission peak of green light. In contrast, the maximum current efficiency and power efficiency of the device without CuPc are only 4.0 cd/A at 100 mA/cm2 and 4.2 lm/W at 3.6 V, respectively.

  5. Light Quality Affects Chloroplast Electron Transport Rates Estimated from Chl Fluorescence Measurements.

    Science.gov (United States)

    Evans, John R; Morgan, Patrick B; von Caemmerer, Susanne

    2017-10-01

    Chl fluorescence has been used widely to calculate photosynthetic electron transport rates. Portable photosynthesis instruments allow for combined measurements of gas exchange and Chl fluorescence. We analyzed the influence of spectral quality of actinic light on Chl fluorescence and the calculated electron transport rate, and compared this with photosynthetic rates measured by gas exchange in the absence of photorespiration. In blue actinic light, the electron transport rate calculated from Chl fluorescence overestimated the true rate by nearly a factor of two, whereas there was closer agreement under red light. This was consistent with the prediction made with a multilayer leaf model using profiles of light absorption and photosynthetic capacity. Caution is needed when interpreting combined measurements of Chl fluorescence and gas exchange, such as the calculation of CO2 partial pressure in leaf chloroplasts. © Crown copyright 2017.

  6. Simulating fluorescence light-canopy interaction in support of laser-induced fluorescence measurements

    International Nuclear Information System (INIS)

    Rosema, A.; Verhoef, W.; Schroote, J.; Snel, J.F.H.

    1991-01-01

    In the Netherlands an operational field instrument for the measurement of laser induced fluorescence of vegetation (LEAF) is developed. In addition, plant physiological and remote sensing research is done to support this new remote sensing instrument. This paper presents a general introduction on the subject of laser-induced fluorescence, including the relation between chlorophyll fluorescence and photosynthesis, spectral characteristics, and previous research. Also the LEAF system is briefly described. Subsequently, the development of a leaf fluorescence model (KMF) and a canopy fluorescence model (FLSAIL) are reported. With these simulation models a sensitivity study is carried out. Fluorescence of 685 nm appears to be most suitable to obtain information on photosynthesis and stress, but is also influenced by canopy structure. Separation of these two effects is studied

  7. Instrument for fluorescence sensing of circulating cells with diffuse light in mice in vivo

    OpenAIRE

    Zettergren, Eric; Vickers, Dwayne; Runnels, Judith; Murthy, Shashi K.; Lin, Charles P.; Niedre, Mark

    2012-01-01

    Accurate quantification of circulating cell populations in mice is important in many areas of preclinical biomedical research. Normally, this is done either by extraction and analysis of small blood samples or, more recently, by using microscopy-based in vivo fluorescence flow cytometry. We describe a new technological approach to this problem using detection of diffuse fluorescent light from relatively large blood vessels in vivo. The diffuse fluorescence flow cytometer (DFFC) uses a laser t...

  8. A method for the rapid generation of nonsequential light-response curves of chlorophyll fluorescence.

    Science.gov (United States)

    Serôdio, João; Ezequiel, João; Frommlet, Jörg; Laviale, Martin; Lavaud, Johann

    2013-11-01

    Light-response curves (LCs) of chlorophyll fluorescence are widely used in plant physiology. Most commonly, LCs are generated sequentially, exposing the same sample to a sequence of distinct actinic light intensities. These measurements are not independent, as the response to each new light level is affected by the light exposure history experienced during previous steps of the LC, an issue particularly relevant in the case of the popular rapid light curves. In this work, we demonstrate the proof of concept of a new method for the rapid generation of LCs from nonsequential, temporally independent fluorescence measurements. The method is based on the combined use of sample illumination with digitally controlled, spatially separated beams of actinic light and a fluorescence imaging system. It allows the generation of a whole LC, including a large number of actinic light steps and adequate replication, within the time required for a single measurement (and therefore named "single-pulse light curve"). This method is illustrated for the generation of LCs of photosystem II quantum yield, relative electron transport rate, and nonphotochemical quenching on intact plant leaves exhibiting distinct light responses. This approach makes it also possible to easily characterize the integrated dynamic light response of a sample by combining the measurement of LCs (actinic light intensity is varied while measuring time is fixed) with induction/relaxation kinetics (actinic light intensity is fixed and the response is followed over time), describing both how the response to light varies with time and how the response kinetics varies with light intensity.

  9. Development of a new light collection and detection system optimized for ion beam induced fluorescence microscopy

    International Nuclear Information System (INIS)

    Vanga, Sudheer Kumar; Mi, Zhaohong; Koh, Long Cheng; Tao, Ye; Bettiol, Andrew A.; Watt, Frank

    2015-01-01

    Ion beam induced fluorescence microscopy is a new imaging technique which has the potential to achieve sub-50 nm spatial resolution fluorescence images. Currently the resolution of the technique has been limited to around 150 nm mainly because of inefficient collection and detection of emitted photons from the sample. To overcome this limitation, a new light collection system based on a custom made parabolic mirror is employed to enhance the fluorescence collection. The custom made mirror is designed so as to obtain both structural (scanning transmission ion microscopy) and ion beam induced fluorescence imaging simultaneously. The design and characterization of the parabolic mirror is discussed in detail

  10. Fluorescence relaxation spectroscopy : light on dynamical structures of flavoproteins

    NARCIS (Netherlands)

    Burten - Bastiaens, P.I.H.

    1992-01-01

    Refinements in technique and data analysis have opened new avenues for a detailed interpretation of protein fluorescence. What is more, by combining new insights in protein structure and dynamics with improved knowledge of photophysics of biological chromophores, the coupling between

  11. Comparative Phenotypical and Molecular Analyses of Arabidopsis Grown under Fluorescent and LED Light

    Directory of Open Access Journals (Sweden)

    Franka Seiler

    2017-06-01

    Full Text Available Comparative analyses of phenotypic and molecular traits of Arabidopsis thaliana grown under standardised conditions is still a challenge using climatic devices supplied with common light sources. These are in most cases fluorescent lights, which have several disadvantages such as heat production at higher light intensities, an invariable spectral output, and relatively rapid “ageing”. This results in non-desired variations of growth conditions and lowers the comparability of data acquired over extended time periods. In this study, we investigated the growth behaviour of Arabidopsis Col0 under different light conditions, applying fluorescent compared to LED lamps, and we conducted physiological as well as gene expression analyses. By changing the spectral composition and/or light intensity of LEDs we can clearly influence the growth behaviour of Arabidopsis and thereby study phenotypic attributes under very specific light conditions that are stable and reproducible, which is not necessarily given for fluorescent lamps. By using LED lights, we can also roughly mimic the sun light emission spectrum, enabling us to study plant growth in a more natural-like light set-up. We observed distinct growth behaviour under the different light regimes which was reflected by physiological properties of the plants. In conclusion, LEDs provide variable emission spectra for studying plant growth under defined, stable light conditions.

  12. Separation of ballistic and diffusive fluorescence photons in confocal Light-Sheet Microscopy of Arabidopsis roots

    Science.gov (United States)

    Meinert, Tobias; Tietz, Olaf; Palme, Klaus J.; Rohrbach, Alexander

    2016-01-01

    Image quality in light-sheet fluorescence microscopy is strongly affected by the shape of the illuminating laser beam inside embryos, plants or tissue. While the phase of Gaussian or Bessel beams propagating through thousands of cells can be partly controlled holographically, the propagation of fluorescence light to the detector is difficult to control. With each scatter process a fluorescence photon loses information necessary for the image generation. Using Arabidopsis root tips we demonstrate that ballistic and diffusive fluorescence photons can be separated by analyzing the image spectra in each plane without a priori knowledge. We introduce a theoretical model allowing to extract typical scattering parameters of the biological material. This allows to attenuate image contributions from diffusive photons and to amplify the relevant image contributions from ballistic photons through a depth dependent deconvolution. In consequence, image contrast and resolution are significantly increased and scattering artefacts are minimized especially for Bessel beams with confocal line detection. PMID:27553506

  13. Charting Monosynaptic Connectivity Maps by Two-Color Light-Sheet Fluorescence Microscopy

    Directory of Open Access Journals (Sweden)

    Christian J. Niedworok

    2012-11-01

    Full Text Available Cellular resolution three-dimensional (3D visualization of defined, fluorescently labeled long-range neuronal networks in the uncut adult mouse brain has been elusive. Here, a virus-based strategy is described that allowed fluorescent labeling of centrifugally projecting neuronal populations in the ventral forebrain and their directly, monosynaptically connected bulbar interneurons upon a single stereotaxic injection into select neuronal populations. Implementation of improved tissue clearing combined with light-sheet fluorescence microscopy permitted imaging of the resulting connectivity maps in a single whole-brain scan. Subsequent 3D reconstructions revealed the exact distribution of the diverse neuronal ensembles monosynaptically connected with distinct bulbar interneuron populations. Moreover, rehydratation of brains after light-sheet fluorescence imaging enabled the immunohistochemical identification of synaptically connected neurons. Thus, this study describes a method for identifying monosynaptic connectivity maps from distinct, virally labeled neuronal populations that helps in better understanding of information flow in neural systems.

  14. Separation of ballistic and diffusive fluorescence photons in confocal Light-Sheet Microscopy of Arabidopsis roots.

    Science.gov (United States)

    Meinert, Tobias; Tietz, Olaf; Palme, Klaus J; Rohrbach, Alexander

    2016-08-24

    Image quality in light-sheet fluorescence microscopy is strongly affected by the shape of the illuminating laser beam inside embryos, plants or tissue. While the phase of Gaussian or Bessel beams propagating through thousands of cells can be partly controlled holographically, the propagation of fluorescence light to the detector is difficult to control. With each scatter process a fluorescence photon loses information necessary for the image generation. Using Arabidopsis root tips we demonstrate that ballistic and diffusive fluorescence photons can be separated by analyzing the image spectra in each plane without a priori knowledge. We introduce a theoretical model allowing to extract typical scattering parameters of the biological material. This allows to attenuate image contributions from diffusive photons and to amplify the relevant image contributions from ballistic photons through a depth dependent deconvolution. In consequence, image contrast and resolution are significantly increased and scattering artefacts are minimized especially for Bessel beams with confocal line detection.

  15. Combining electrophoresis with detection under ultraviolet light and multiple ultrafiltration for isolation of humic fluorescence fractions.

    Science.gov (United States)

    Trubetskaya, Olga E; Shaloiko, Lubov A; Demin, Dmitrii V; Marchenkov, Victor V; Proskuryakov, Ivan I; Coelho, Christian; Trubetskoj, Oleg A

    2011-04-01

    Polyacrylamide gel electrophoresis of chernozem soil humic acids (HAs) followed by observation under UV (312 nm) excitation light reveals new low molecular weight (MW) fluorescent fractions. Ultrafiltration of HAs sample in 7 M urea on a membrane of low nominal MW retention (NMWR, 5 kDa) was repetitively used for separation of fluorescent and non-fluorescent species. Thirty ultrafiltrates and the final retentate R were obtained. Fluorescence maxima of separate ultrafiltrates were different and non-monotonously changed in the range of 475-505 nm. Fluorescence maxima of less than 490 nm were detected only in the four first utrafiltrates. For further physical-chemical analyses all utrafiltrates were combined into a fraction called UFchernozem soil HAs complex. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Light adaptation of the unicellular red alga, Cyanidioschyzon merolae, probed by time-resolved fluorescence spectroscopy.

    Science.gov (United States)

    Ueno, Yoshifumi; Aikawa, Shimpei; Kondo, Akihiko; Akimoto, Seiji

    2015-08-01

    Photosynthetic organisms change the quantity and/or quality of their pigment-protein complexes and the interactions among these complexes in response to light conditions. In the present study, we analyzed light adaptation of the unicellular red alga Cyanidioschyzon merolae, whose pigment composition is similar to that of cyanobacteria because its phycobilisomes (PBS) lack phycoerythrin. C. merolae were grown under different light qualities, and their responses were measured by steady-state absorption, steady-state fluorescence, and picosecond time-resolved fluorescence spectroscopies. Cells were cultivated under four monochromatic light-emitting diodes (blue, green, yellow, and red), and changes in pigment composition and energy transfer were observed. Cells grown under blue and green light increased their relative phycocyanin levels compared with cells cultured under white light. Energy-transfer processes to photosystem I (PSI) were sensitive to yellow and red light. The contribution of direct energy transfer from PBS to PSI increased only under yellow light, while red light induced a reduction in energy transfer from photosystem II to PSI and an increase in energy transfer from light-harvesting chlorophyll protein complex I to PSI. Differences in pigment composition, growth, and energy transfer under different light qualities are discussed.

  17. Fish with red fluorescent eyes forage more efficiently under dim, blue-green light conditions.

    Science.gov (United States)

    Harant, Ulrike Katharina; Michiels, Nicolaas Karel

    2017-04-20

    Natural red fluorescence is particularly conspicuous in the eyes of some small, benthic, predatory fishes. Fluorescence also increases in relative efficiency with increasing depth, which has generated speculation about its possible function as a "light organ" to detect cryptic organisms under bluish light. Here we investigate whether foraging success is improved under ambient conditions that make red fluorescence stand out more, using the triplefin Tripterygion delaisi as a model system. We repeatedly presented 10 copepods to individual fish (n = 40) kept under a narrow blue-green spectrum and compared their performance with that under a broad spectrum with the same overall brightness. The experiment was repeated for two levels of brightness, a shaded one representing 0.4% of the light present at the surface and a heavily shaded one with about 0.01% of the surface brightness. Fish were 7% more successful at catching copepods under the narrow, fluorescence-friendly spectrum than under the broad spectrum. However, this effect was significant under the heavily shaded light treatment only. This outcome corroborates previous predictions that fluorescence may be an adaptation to blue-green, heavily shaded environments, which coincides with the opportunistic biology of this species that lives in the transition zone between exposed and heavily shaded microhabitats.

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

    Science.gov (United States)

    Shashkova, Sviatlana; Leake, Mark C

    2017-08-31

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

  19. Mechanistic studies of the genetically encoded fluorescent protein voltage probe ArcLight.

    Directory of Open Access Journals (Sweden)

    Zhou Han

    Full Text Available ArcLight, a genetically encoded fluorescent protein voltage probe with a large ΔF/ΔV, is a fusion between the voltage sensing domain of the Ciona instestinalis voltage sensitive phosphatase and super ecliptic pHluorin carrying a single mutation (A227D in the fluorescent protein. Without this mutation the probe produces only a very small change in fluorescence in response to voltage deflections (∼ 1%. The large signal afforded by this mutation allows optical detection of action potentials and sub-threshold electrical events in single-trials in vitro and in vivo. However, it is unclear how this single mutation produces a probe with such a large modulation of its fluorescence output with changes in membrane potential. In this study, we identified which residues in super ecliptic pHluorin (vs eGFP are critical for the ArcLight response, as a similarly constructed probe based on eGFP also exhibits large response amplitude if it carries these critical residues. We found that D147 is responsible for determining the pH sensitivity of the fluorescent protein used in these probes but by itself does not result in a voltage probe with a large signal. We also provide evidence that the voltage dependent signal of ArcLight is not simply sensing environmental pH changes. A two-photon polarization microscopy study showed that ArcLight's response to changes in membrane potential includes a reorientation of the super ecliptic pHluorin. We also explored different changes including modification of linker length, deletion of non-essential amino acids in the super ecliptic pHluorin, adding a farnesylation site, using tandem fluorescent proteins and other pH sensitive fluorescent proteins.

  20. A comparative study of fluorescent and LED lighting in industrial facilities

    Science.gov (United States)

    Perdahci PhD, C.; Akin BSc, H. C.; Cekic Msc, O.

    2018-05-01

    Industrial facilities have always been in search for reducing outgoings and minimizing energy consumption. Rapid developments in lighting technology require more energy efficient solutions not only for industries but also for many sectors and for households. Addition of solid-state technology has brought LED lamps into play and with LED lamp usage, efficacy level has reached its current values. Lighting systems which uses fluorescent and LED lamps have become the prior choice for many industrial facilities. This paper presents a comparative study about fluorescent and LED based indoor lighting systems for a warehouse building in an industrial facility in terms of lighting distribution values, colour rendering, power consumption, energy efficiency and visual comfort. Both scenarios have been modelled and simulated by using Relux and photometric data for the luminaires have been gathered by conducting tests and measurements in an accredited laboratory.

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

    Science.gov (United States)

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

    2016-03-01

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

  2. Improved efficiency of organic light-emitting diodes based on a europium complex by fluorescent dye

    Energy Technology Data Exchange (ETDEWEB)

    You Han [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Fang Junfeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Gao Jia [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Ma Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China)]. E-mail: mdg1014@ciac.jl.cn

    2007-01-15

    Improved efficiency of organic light-emitting diodes (OLEDs) based on europium complexes have been realized by using a fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6 (1,1,7,7-tetramethyljulolidyl-9-enyl))-4H-pyran (DCJTB) doping .The luminous efficiency of the devices with a fluorescent dye in the emissive layer was found to improve two times of that in devices without fluorescent dye. The devices showed pure red light, which is the characteristic emission of trivalent europium ion with a full-width at half-maximum of 3 nm.The maximum brightness and luminous efficiency reached 1200 cd/m{sup 2} at 23 V and 7.3 cd/A (2.0 lm/w), respectively, at a current density of 0.35 mA/cm{sup 2}.

  3. Fluorescence digital photography of acne using a light-emitting diode illuminator.

    Science.gov (United States)

    Ahn, Hyo Hyun; Kim, Soo Nam; Kye, Young Chul

    2006-11-01

    The fluorescence findings of several dermatological diseases, such as erythrasma, tinea versicolor, and acne are helpful for diagnosis and follow-up. However, many experience difficulty taking photographic images of fluorescence. The aim of this study was to develop a 405 nm light-emitting diode (LED) system for fluorescence digital photography of acne and to determine whether such a diode can be used to evaluate acne. Eight healthy acne patients were compared with controls by fluorescence digital photography using a digital camera equipped with a 405 nm LED illuminator. Digital photographs were taken by two different ways of exposure, i.e. appropriate exposure level and longer exposure. One side of the nose, cheek, and glabella was compared. The numbers and extents of fluorescence dots were counted and measured. As normal controls, seven individuals with apparent oiliness and no acne were enrolled. Red fluorescent facial dots were observed and photographed digitally using the 405 nm LED illuminator. These were more numerous and extensive on the glabella and cheeks of acne patients. Fluorescence digital photography of acne was successfully performed using a 405 nm LED illuminator. This illuminator could be used for acne evaluations.

  4. Fluorescent light irradiation and its mutagenic potential in cultured mammalian cells

    International Nuclear Information System (INIS)

    Pant, K.; Thilager, A.

    1994-01-01

    The photobiological effect of light is characterized by its energy emission at different wave lengths. Therefore by studying the energy emission spectra at different light sources and their photobiological activities, one can relate wavelength range(s) of the spectrum to a particular photobiological effect. We studied the potential of light irradiation from standard fluorescent bulbs (Sylvania 34WT-12) used in offices and laboratories to induce unscheduled DNA Synthesis (UDS) and mutations in cultured mammalian cells. The energy emission spectrum of the bulbs was determined at every 10 nanometers from 300nM to 700nM. The Chinese hamster ovary (CHO) cells were used to study the induction of mutations at the Hypoxanthine Guanine Phosphoribosyl Transferase (HGPRT) locus. Primary rat hepatocyte cultures were used to study the effect of light irradiation on UDS. The CHO cells were cultured in tissue culture flasks in minimum light conditions (.02mw/cm 2 ) and exposed to light irradiations with durations from 0 to 40 minutes. The cultures were maintained in darkness during the expression period and evaluated for HGPRT mutant frequencies. Similarly, the primary rat hepatocyte cultures were cultured on cover slips under minimal light conditions except for light irradiation and evaluated for UDS using 3H-thymidine labelled auto-radiography. The results of the study indicate that irradiation from fluorescent lights caused a slight elevation in the HGPRT mutant frequency in CHO cells. However a significant increase in UDS was not observed even at the maximum light irradiation dose. These results were compared to data obtained from similar experiments conducted with fluorescent bulbs with different energy emission spectra

  5. Fluorescent light irradiation and its mutagenic potential in microorganisms and cultured mammalian cells

    International Nuclear Information System (INIS)

    Thilagar, A.; Kumaraoo, P.V.; Ku, J.

    1994-01-01

    The photobiological effect of light is characterized by its energy emission at different wave lengths. Therefore by studying the energy emission spectra at different light sources and their photobiological activities, one can relate wavelength range(s) of the spectra to a particular photobiological effect. We studied the mutagenic and clastogenic potentials of light irradiation from standard fluorescent bulbs used in offices and laboratories. The energy emission spectrum of the bulbs was determined at every 10 nanometers from 300nM to 700nM. Salmonella typhimurium (strain TA100) and Escherichia coli (strain WP2uvrA) were used to study the induction of mutations in microorganisms. Chinese hamster ovary (CHO) cells were used to study the induction of chromosome aberrations. The microorganisms were plated under minimum light conditions ( 2 ) and exposed to the light source at 0.35mw/cm 2 for durations ranging from 0 to 40 minutes. The plates were incubated in darkness and the colonies were counted to determine the reversion frequencies. Similarly, the CHO cells are cultured in tissue culture flasks in minimum light conditions except for the light irradiations. The cultures were then evaluated for chromosome aberrations. The results of these studies indicated that irradiation from fluorescent lights induced a clear dose dependent increase in the reversion frequency in TA100. However the reversion frequencies in E. coli strain WP2uvrA were not substantially elevated at the maximum light irradiation condition. A significant increase in the chromosome aberrations frequency was not observed even at the maximum light irradiation dose used in this study. These results were compared to data obtained from similar experiments conducted with fluorescent bulbs with different energy emission spectra. The results of these studies are presented in this paper

  6. Application of spectrally resolved fluorescence induction to study light-induced nonphotochemical quenching in algae

    Czech Academy of Sciences Publication Activity Database

    Kaňa, Radek

    2018-01-01

    Roč. 56, č. 1 (2018), s. 132-138 ISSN 0300-3604 R&D Projects: GA MŠk(CZ) LO1416; GA ČR(CZ) GA16-10088S Institutional support: RVO:61388971 Keywords : fluorescence parameters * light-harvesting complex * photoprotection Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.507, year: 2016

  7. Nanoscale Confinement and Fluorescence Effects of Bacterial Light Harvesting Complex LH2 in Mesoporous Silicas

    DEFF Research Database (Denmark)

    Ikemoto, Hideki; Tubasum, Sumera; Pullerits, Tonu

    2013-01-01

    Many key chemical and biochemical reactions, particularly in living cells, take place in confined space at the mesoscopic scale. Towards understanding of physicochemical nature of biomacromolecules confined in nanoscale space, in this work we have elucidated fluorescent effects of a light harvest...

  8. Energy Efficiency Comparison between Compact Fluorescent Lamp and Common Light Bulb

    Science.gov (United States)

    Tanushevsk, Atanas; Rendevski, Stojan

    2016-01-01

    For acquainting the students of applied physics and students of teaching physics with the concept of energy efficiency, electrical and spectral characteristics of two widely used lamps--integrated fluorescence lamp and common light bulb have been investigated. Characterization of the lamps has been done by measuring the spectral irradiance and…

  9. Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

    Science.gov (United States)

    Maia, Ana Marly Araújo; de Freitas, Anderson Zanardi; de L Campello, Sergio; Gomes, Anderson Stevens Leônidas; Karlsson, Lena

    2016-06-01

    An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Localization of fluorescently labeled structures in frozen-hydrated samples using integrated light electron microscopy

    NARCIS (Netherlands)

    Faas, F.G.A.; Bárcena, M.A.; Agronskaia, A.V.; Gerritsen, H.C.; Moscicka, K.B.; Diebolder, C.A.; Driel, L.F.; Limpens, R.W.A.L.; Bos, E.; Ravelli, R.B.G.; Koning, R.I.; Koster, A.J.

    2013-01-01

    Correlative light and electron microscopy is an increasingly popular technique to study complex biological systems at various levels of resolution. Fluorescence microscopy can be employed to scan large areas to localize regions of interest which are then analyzed by electron microscopy to obtain

  11. Control Rod Malfunction at the NRAD Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L. Maddock

    2010-05-01

    The neutron Radiography Reactor (NRAD) is a training, research, and isotope (TRIGA) reactor located at the INL. The reactor is normally shut down by the insertion of three control rods that drop into the core when power is removed from electromagnets. During a routine shutdown, indicator lights on the console showed that one of the control rods was not inserted. It was initially thought that the indicator lights were in error because of a limit switch that was out of adjustment. Through further testing, it was determined that the control rod did not drop when the scram switch was initially pressed. The control rod anomaly led to a six month shutdown of the reactor and an in depth investigation of the reactor protective system. The investigation looked into: scram switch operation, console modifications, and control rod drive mechanisms. A number of latent issues were discovered and corrected during the investigation. The cause of the control rod malfunction was found to be a buildup of corrosion in the control rod drive mechanism. The investigation resulted in modifications to equipment, changes to both operation and maintenance procedures, and additional training. No reoccurrences of the problem have been observed since corrective actions were implemented.

  12. The TUS space fluorescence detector for study of UHECR and other phenomena of variable fluorescence light in the atmosphere

    Science.gov (United States)

    Abrashkin, V.; Alexandrov, V.; Arakcheev, Y.; Bitkin, E.; Cordero, A.; Eremin, S.; Finger, M.; Garipov, G.; Grebenyuk, V.; Kalmykov, N.; Khrenov, B.; Koval, V.; Martinez, O.; Matyushkin, A.; Moreno, E.; Naumov, D.; Olshevsky, A.; Panasyuk, M.; Park, I.; Robledo, C.; Rubinstein, I.; Sharakin, S.; Silaev, A.; Tkatchev, L.; Tulupov, V.; Tyukaev, R.; Sabirov, B.; Salazar, H.; Saprykin, O.; Syromyatnikov, V.; Urmantsev, F.; Villasenor, L.; Yashin, I.; Zaikin, N.; Zepeda, A.

    The Tracking Ultraviolet Set Up (TUS) instrument has been designed to observe from space the fluorescence light in the atmosphere when Extensive Air Shower (EAS) or other phenomena such as meteors or dust grains traverse it. The TUS design concepts will allow us to construct the next generation of fluorescence detectors with increasing light collection power and higher resolution. The KLYPVE instrument with collection power 5 times larger of the TUS will be the next space detector. Light collection is obtained with the help of segmented “low frequency Fresnel type” mirrors. Photo receiver retina in the focal consists of modules of PM tubes. For stable performance in conditions of variable light noise and variable temperature the tube type with a multi-alcali cathode was chosen. Voltage supplies for PMT in one module were designed for keeping the performance of photo receiver retina uniform when the tube gain change. From every tube the signal amplitude is recorded in time bins of 400 ns. The digital data are kept and analyzed in the module FPGA connected to the central FPGA controlling all data. The RAM memory is large, capable to record events with different duration of the light signal (up to several seconds). The preliminary event data are analyzed in the triggering system of the central FPGA. The trigger criteria have several options for events of different origin (different pixel signal duration). The trigger integration time is controlled from the space mission center. The performances of the detector were simulated and zenith angle dependent trigger efficiencies were calculated. The TUS detector will be efficient in recording “horizontal” EAS (zenith angles more than 60°), developed to their maximum above the cloud cover. The EAS Cherenkov light, back scattered from the cloud cover, will be recorded and will improve data on the EAS direction and position of maximum. For better accuracy in physical parameters of the events and for the experimental

  13. STUDIES ON BIOLUMINESCENCE : XVII. FLUORESCENCE AND INHIBITION OF LUMINESCENCE IN CTENOPHORES BY ULTRA-VIOLET LIGHT.

    Science.gov (United States)

    Harvey, E N

    1925-01-20

    1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue. 2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark. 3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light). 4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material. 5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material. 6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent. 7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents.

  14. Acclimatization of symbiotic corals to mesophotic light environments through wavelength transformation by fluorescent protein pigments.

    Science.gov (United States)

    Smith, Edward G; D'Angelo, Cecilia; Sharon, Yoni; Tchernov, Dan; Wiedenmann, Joerg

    2017-07-12

    The depth distribution of reef-building corals exposes their photosynthetic symbionts of the genus Symbiodinium to extreme gradients in the intensity and spectral quality of the ambient light environment. Characterizing the mechanisms used by the coral holobiont to respond to the low intensity and reduced spectral composition of the light environment in deeper reefs (greater than 20 m) is fundamental to our understanding of the functioning and structure of reefs across depth gradients. Here, we demonstrate that host pigments, specifically photoconvertible red fluorescent proteins (pcRFPs), can promote coral adaptation/acclimatization to deeper-water light environments by transforming the prevalent blue light into orange-red light, which can penetrate deeper within zooxanthellae-containing tissues; this facilitates a more homogeneous distribution of photons across symbiont communities. The ecological importance of pcRFPs in deeper reefs is supported by the increasing proportion of red fluorescent corals with depth (measured down to 45 m) and increased survival of colour morphs with strong expression of pcRFPs in long-term light manipulation experiments. In addition to screening by host pigments from high light intensities in shallow water, the spectral transformation observed in deeper-water corals highlights the importance of GFP-like protein expression as an ecological mechanism to support the functioning of the coral- Symbiodinium association across steep environmental gradients. © 2017 The Authors.

  15. Spatial distribution of fluorescent light emitted from neon and nitrogen excited by low energy electron beams

    International Nuclear Information System (INIS)

    Morozov, A.; Kruecken, R.; Ulrich, A.; Wieser, J.

    2006-01-01

    Side-view intensity profiles of fluorescent light were measured for neon and nitrogen excited with 12 keV electron beams at gas pressures from 250 to 1400 hPa. The intensity profiles were compared with theoretical profiles calculated using the CASINO program which performs Monte Carlo simulations of electron scattering. It was assumed that the spatial distribution of fluorescent intensity is directly proportional to the spatial distribution of energy loss by primary electrons. The comparison shows good correlation of experimental data and the results of numeric simulations

  16. Correlative cryo-fluorescence light microscopy and cryo-electron tomography of Streptomyces.

    Science.gov (United States)

    Koning, Roman I; Celler, Katherine; Willemse, Joost; Bos, Erik; van Wezel, Gilles P; Koster, Abraham J

    2014-01-01

    Light microscopy and electron microscopy are complementary techniques that in a correlative approach enable identification and targeting of fluorescently labeled structures in situ for three-dimensional imaging at nanometer resolution. Correlative imaging allows electron microscopic images to be positioned in a broader temporal and spatial context. We employed cryo-correlative light and electron microscopy (cryo-CLEM), combining cryo-fluorescence light microscopy and cryo-electron tomography, on vitrified Streptomyces bacteria to study cell division. Streptomycetes are mycelial bacteria that grow as long hyphae and reproduce via sporulation. On solid media, Streptomyces subsequently form distinct aerial mycelia where cell division leads to the formation of unigenomic spores which separate and disperse to form new colonies. In liquid media, only vegetative hyphae are present divided by noncell separating crosswalls. Their multicellular life style makes them exciting model systems for the study of bacterial development and cell division. Complex intracellular structures have been visualized with transmission electron microscopy. Here, we describe the methods for cryo-CLEM that we applied for studying Streptomyces. These methods include cell growth, fluorescent labeling, cryo-fixation by vitrification, cryo-light microscopy using a Linkam cryo-stage, image overlay and relocation, cryo-electron tomography using a Titan Krios, and tomographic reconstruction. Additionally, methods for segmentation, volume rendering, and visualization of the correlative data are described. © 2014 Elsevier Inc. All rights reserved.

  17. Quantified light-induced fluorescence, review of a diagnostic tool in prevention of oral disease

    Science.gov (United States)

    de Josselin de Jong, Elbert; Higham, Susan M.; Smith, Philip W.; van Daelen, Catherina J.; van der Veen, Monique H.

    2009-05-01

    Diagnostic methods for the use in preventive dentistry are being developed continuously. Few of these find their way into general practice. Although the general trend in medicine is to focus on disease prevention and early diagnostics, in dentistry this is still not the case. Nevertheless, in dental research some of these methods seem to be promising for near future use by the general dental professional. In this paper an overview is given of a method called quantitative light-induced fluorescence or (QLF) in which visible and harmless light excites the teeth in the patient's mouth to produce fluorescent images, which can be stored on disk and computer analyzed. White spots (early dental caries) are detected and quantified as well as bacterial metabolites on and in the teeth. An overview of research to validate the technique and modeling to further the understanding of the technique by Monte Carlo simulation is given and it is shown that the fluorescence phenomena can be described by the simulation model in a qualitative way. A model describing the visibility of red fluorescence from within the dental tissue is added, as this was still lacking in current literature. An overview is given of the clinical images made with the system and of the extensive research which has been done. The QLF™ technology has been shown to be of importance when used in clinical trials with respect to the testing of toothpastes and preventive treatments. It is expected that the QLF™ technology will soon find its way into the general dental practice.

  18. Simultaneous measurement of amyloid fibril formation by dynamic light scattering and fluorescence reveals complex aggregation kinetics.

    Directory of Open Access Journals (Sweden)

    Aaron M Streets

    Full Text Available An apparatus that combines dynamic light scattering and Thioflavin T fluorescence detection is used to simultaneously probe fibril formation in polyglutamine peptides, the aggregating subunit associated with Huntington's disease, in vitro. Huntington's disease is a neurodegenerative disorder in a class of human pathologies that includes Alzheimer's and Parkinson's disease. These pathologies are all related by the propensity of their associated protein or polypeptide to form insoluble, β-sheet rich, amyloid fibrils. Despite the wide range of amino acid sequence in the aggregation prone polypeptides associated with these diseases, the resulting amyloids display strikingly similar physical structure, an observation which suggests a physical basis for amyloid fibril formation. Thioflavin T fluorescence reports β-sheet fibril content while dynamic light scattering measures particle size distributions. The combined techniques allow elucidation of complex aggregation kinetics and are used to reveal multiple stages of amyloid fibril formation.

  19. Light-sheet fluorescence imaging to localize cardiac lineage and protein distribution

    Science.gov (United States)

    Ding, Yichen; Lee, Juhyun; Ma, Jianguo; Sung, Kevin; Yokota, Tomohiro; Singh, Neha; Dooraghi, Mojdeh; Abiri, Parinaz; Wang, Yibin; Kulkarni, Rajan P.; Nakano, Atsushi; Nguyen, Thao P.; Fei, Peng; Hsiai, Tzung K.

    2017-02-01

    Light-sheet fluorescence microscopy (LSFM) serves to advance developmental research and regenerative medicine. Coupled with the paralleled advances in fluorescence-friendly tissue clearing technique, our cardiac LSFM enables dual-sided illumination to rapidly uncover the architecture of murine hearts over 10 by 10 by 10 mm3 in volume; thereby allowing for localizing progenitor differentiation to the cardiomyocyte lineage and AAV9-mediated expression of exogenous transmembrane potassium channels with high contrast and resolution. Without the steps of stitching image columns, pivoting the light-sheet and sectioning the heart mechanically, we establish a holistic strategy for 3-dimentional reconstruction of the “digital murine heart” to assess aberrant cardiac structures as well as the spatial distribution of the cardiac lineages in neonates and ion-channels in adults.

  20. Instrument for fluorescence sensing of circulating cells with diffuse light in mice in vivo.

    Science.gov (United States)

    Zettergren, Eric; Vickers, Dwayne; Runnels, Judith; Murthy, Shashi K; Lin, Charles P; Niedre, Mark

    2012-03-01

    Accurate quantification of circulating cell populations in mice is important in many areas of preclinical biomedical research. Normally, this is done either by extraction and analysis of small blood samples or, more recently, by using microscopy-based in vivo fluorescence flow cytometry. We describe a new technological approach to this problem using detection of diffuse fluorescent light from relatively large blood vessels in vivo. The diffuse fluorescence flow cytometer (DFFC) uses a laser to illuminate a mouse limb and an array of optical fibers coupled to a high-sensitivity photomultiplier tube array operating in photon counting mode to detect weak fluorescence signals from cells. We first demonstrate that the DFFC instrument is capable of detecting fluorescent microspheres and Vybrant-DiD-labeled cells in a custom-made optical flow phantom with similar size, optical properties, linear flow rates, and autofluorescence as a mouse limb. We also present preliminary data demonstrating that the DFFC is capable of detecting circulating cells in nude mice in vivo. In principle, this device would allow interrogation of the whole blood volume of a mouse in minutes, with sensitivity improvement by several orders of magnitude compared to current approaches. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE).

  1. Photosynthesis and chlorophyll fluorescence reaction to different shade stresses of weak light sensitive maize

    International Nuclear Information System (INIS)

    Wang, J.; Li, F.; Shi, Z.; Huang, H.; Jia, S.

    2017-01-01

    A split-plot experimental study was conducted to evaluate the effect of different shade stresses on photosynthesis and chlorophyll fluorescence of maize leaves.The experiment was designed on the south farm of Special Corn Institute, Shenyang Agricultural University, China.Data was collected from the day maize tasseled (Jul. 21) to the beginning of grouting (Aug.12 ) under 18%, 28%, 38%, 60%, and 75% shade stress to determine indexes such as photosynthesis and chlorophyll fluorescence after 15 days of shade treatment. Pairs of near-isogenic lines (NILs) of Shennong 98A (a barren stalk inbred line) and Shennong 98B (an un-barren stalk inbred line) were used as experimental materials to further reveal photosynthetic mechanisms of weak light sensitive maize when exposed to weak light conditions. Thus, a foundation was established for high density-resistant (shade resistant) corn breeding,while identifying weak light sensitive varieties. After shading treatment, chlorophyll a and total chlorophyll content of both varieties increased, chlorophyll b content first increased, followed by a decrease, while the net photosynthetic rate and stomatal conductance showed a gradually decreasing trend. The changing trends of photochemical quenching coefficient(qp) and effective quantum yield of PSII photochemistry (FPSII)were similar, FPSII and qP increased significantly as shading stress increased from 18% to 38%;however, FPSII and qP declined significantly under 60% and 75% shading stresses. The changing trend of NPQ was opposite to FPSII and qP. A comparison of both inbred lines showed that photosynthesis and chlorophyll fluorescence characteristics of Shennong 98B were superior to Shennong 98A. This study revealed the relationships between weak light sensitive lines and shade intensities by comparing differences in photosynthesis and chlorophyll fluorescence parameters. (author)

  2. Digital image manipulation of underexposed X-rays - examinations with a fluorescent light scanner

    International Nuclear Information System (INIS)

    Hidajat, N.; Schroeder, R.J.; Bergh, B.; Cordes, M.; Felix, R.

    1994-01-01

    Incorrect exposure of conventional radiographs frequently leads to repetition of the examination and thereby to increased radiation exposure for the patient. Underexposed films of an Alderson-Rando phantom, an ankle joint and a patella were digitised by means of an inexpensive fluorescent light scanner, and subsequent image manipulation improved quality so as to make the image diagnostically adequate. For the demonstration of markedly underexposed structures digitalisation with subsequent contrast enhancement was used. Well exposed structures are best evaluated in contrast enhanced transmitted light. Our results suggest it should be possible to reduce the number of repeat exposures and thereby to limit radiation exposure. (orig.) [de

  3. High-efficiency white organic light-emitting diodes using thermally activated delayed fluorescence

    International Nuclear Information System (INIS)

    Nishide, Jun-ichi; Hiraga, Yasuhide; Nakanotani, Hajime; Adachi, Chihaya

    2014-01-01

    White organic light-emitting diodes (WOLEDs) have attracted much attention recently, aimed for next-generation lighting sources because of their high potential to realize high electroluminescence efficiency, flexibility, and low-cost manufacture. Here, we demonstrate high-efficiency WOLED using red, green, and blue thermally activated delayed fluorescence materials as emissive dopants to generate white electroluminescence. The WOLED has a maximum external quantum efficiency of over 17% with Commission Internationale de l'Eclairage coordinates of (0.30, 0.38).

  4. Discrimination of Dendrobium officinale and Its Common Adulterants by Combination of Normal Light and Fluorescence Microscopy

    Directory of Open Access Journals (Sweden)

    Chu Chu

    2014-03-01

    Full Text Available The stems of Dendrobium officinale Kimura et Migo, named Tie-pi-shi-hu, is one of the most endangered and precious species in China. Because of its various pharmacodynamic effects, D. officinale is widely recognized as a high-quality health food in China and other countries in south and south-east Asia. With the rising interest of D. officinale, its products have a high price due to a limited supply. This high price has led to the proliferation of adulterants in the market. To ensure the safe use of D. officinale, a fast and convenient method combining normal and fluorescence microscopy was applied in the present study to distinguish D. officinale from three commonly used adulterants including Zi-pi-shi-hu (D. devonianum, Shui-cao-shi-hu (D. aphyllum, Guang-jie-shi-hu (D. gratiosissimum. The result demonstrated that D. officinale could be identified by the characteristic “two hat-shaped” vascular bundle sheath observed under the fluorescence microscopy and the distribution of raphides under normal light microscopy. The other three adulterants could be discriminated by the vascular bundle differences and the distribution of raphides under normal light microscopy. This work indicated that combination of normal light and fluorescence microscopy is a fast and efficient technique to scientifically distinguish D. officinale from the commonly confused species.

  5. The retardation by gamma irradiation of greening in potatoes exposed to fluorescent lighting

    International Nuclear Information System (INIS)

    Beyers, M.

    1981-01-01

    The optimum gamma irradiation treatments for the inhibition of greening of unwashed Up-to-Date potatoes exposed to continuous fluorescent lighting were 0,15 and 0,20 kGy. The 0,15 and 0,20 kGy treated potatoes took 8,7 and 10,3 d longer respectively than the controls for 50% of the potatoes to turn green. The results were verified by chlorophyll determinations. The solanine content of the γ-irradiated potatoes did not differ significantly from that of the controls during the period of exposure. Gamma irradiated tubers which were removed from continuous fluorescent lighting after 7 d to 'household' conditions of daylight and fluorescent light alternated with darkness maintained the quality of day 7 for at least another 16 d. Factors such as washing, packaging, display temperature, post-irradiation pre-illumination storage and cultivar differences did not detract from the effectiveness of γ-irradiation in retarding the greening of potatoes. A comparison of γ-irradiation with dipping inedible oil showed the latter treatment to be more effective than irradiation in inhibiting greening but the treatment caused serious rotting. No difference in the taste or colour of irradiated and nonirradiated potatoes cooked in various ways could be detected [af

  6. Quantitative retinal and choroidal blood flow during light, dark adaptation and flicker light stimulation in rats using fluorescent microspheres.

    Science.gov (United States)

    Shih, Yen-Yu I; Wang, Lin; De La Garza, Bryan H; Li, Guang; Cull, Grant; Kiel, Jeffery W; Duong, Timothy Q

    2013-02-01

    The present study aimed to quantify retinal and choroidal blood flow (BF) during light, dark adaptation and flicker light stimulation using the microsphere technique. Adult male Sprague-Dawley rats were anesthetized with isoflurane. Eyes were dark (Group I, n = 8), light (Group II, n = 8) adapted or stimulated with 10 Hz flicker light (Group III, n = 10). Retinal and choroidal BF were measured by a previously established method, using a mixture of 8 µm yellow-green and 10 µm red fluorescent microspheres. The microspheres were counted ex vivo in the dissected retina and choroid and in the reference arterial blood under a fluorescent microscope. The choroidal BF was 64.8 ± 29 µl/min (mean ± SD) during dark adaptation, not significantly different from that during light adaptation (66.0 ± 17.8 µl/min). The retinal BF was 13.5 ± 3.2 µl/min during 10 Hz flickering light stimulation, significantly higher than that during dark adaptation in the control fellow eyes (9.9 ± 2.9 µl/min). The choroidal BF values were not statistically different between flicker stimulation and dark adaptation. Retinal BF was 11.6 ± 2.9 µl/min during light adaptation. Dark adaptation did not increase retinal BF (Group I, 8.2 ± 2.4 µl/min; Group II, 9.9 ± 2.9 µl/min). These findings argue against a dark-induced or flicker-induced functional hyperemia in the choroid as a result of the demands of the outer retina. Retinal BF was not higher during dark adaptation. Our data support the conclusion that the inner retina has a higher energy demand in flicker conditions relative to dark.

  7. Differential responses of seven contrasting species to high light using pigment and chlorophyll a fluorescence

    Directory of Open Access Journals (Sweden)

    Mittal S.

    2011-05-01

    Full Text Available High light intensity may induce severe photodamage to chloroplast and consequently cause decreases in the yield capacity of plants and destruction of pigments, causing an overall yellowing of the foliage. Thus, study related to light adaptation becomes necessary to understand adaptation processes in higher plants on the basis of which they are characterized as full sunlight or shade plants. Chlorophyll can be regarded as an intrinsic fluorescent probe of the photosynthetic system. The ecophysiological parameter related to plant performance and fitness i.e. in-situ chlorophyll fluorescence measurements were determined for different plant species in the medicinal plant garden of Banasthali University, Rajasthan. Miniaturized Pulse Amplitude Modulated Photosynthetic Yield Analyzers are primarily designed for measuring effective quantum yield (ΔF/Fm’ of photosystem II under momentary ambient light in the field. Photosynthetic yield measurements and light-response curves suggested a gradation of sun-adapted to shade-adapted behaviour of these plants in following order Withania somnifera> Catharanthus roseus> Datura stamonium> Vasica minora> Vasica adulta> Rauwolfia serpentina. As indicated by light response curves and pigment analysis, Datura stramonium, Withania somnifera and Catharanthus roseus competed well photosynthetically and are favoured while Rauwolfia serpentina, Vasica minora, Vasica adulta and Plumbago zeylanica were observed to be less competent photosynthetically. These light response curves and resultant cardinal points study gave insight into the ecophysiological characterization of the photosynthetic capacity of the plant and provides highly interesting parameters like electron transport rate, photo-inhibition, photosynthetically active photon flux density and yield on the basis of which light adaptability was screened for seven medicinally important plants.

  8. Rapid diagnosis of malaria by fluorescent microscopy with light microscope and interface filter

    International Nuclear Information System (INIS)

    Hussain, I.; Tayyib, M.; Farooq, M.; Ahmed, N.

    2008-01-01

    The present study is planned to compare acridine orange (A.O) staining with Giemsa staining by using light microscopy with IF and also with fluorescent microscopy for detection of parasites in peripheral blood of patients suffering from clinically suspected cases of malaria. 200 patients with fever and shivering were included. General investigations like Hb, TLC and platelets were done by sysmex K-1000. Thin and thick blood films were made and stained according to protocol given i.e. by Giemsa and AO stains and slides were examined by different microscopes i.e. light microscope, light microscope with IFS and fluorescent microscope. Out of 200 subjects, 170 (85%) patients showed positive parasitaemia and 30 (15%) subjects were negative for malaria parasites. fib, TLC and platelets were reduced when comparing with MP negative cases. IFS microscope with acridine orange staining showed early detection of malaria parasites by counting fewer fields as compared to light microscopy with Giemsa stains. Time consumed for detection of parasites was also significantly reduced in IFS microscope by using AO stains. (author)

  9. Improving your four-dimensional image: traveling through a decade of light-sheet-based fluorescence microscopy research.

    Science.gov (United States)

    Strobl, Frederic; Schmitz, Alexander; Stelzer, Ernst H K

    2017-06-01

    Light-sheet-based fluorescence microscopy features optical sectioning in the excitation process. This reduces phototoxicity and photobleaching by up to four orders of magnitude compared with that caused by confocal fluorescence microscopy, simplifies segmentation and quantification for three-dimensional cell biology, and supports the transition from on-demand to systematic data acquisition in developmental biology applications.

  10. Contribution to the analysis of light elements using x fluorescence excited by radio-elements

    International Nuclear Information System (INIS)

    Robert, A.

    1964-01-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, β and α emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K α lines of 3. period elements excited by 55 Fe, 3 H/Zr and 210 Po sources; for the 2. period the K α spectra of carbon and of fluorine excited by the α particles of 210 Po. (author) [fr

  11. Visual Understanding of Light Absorption and Waveguiding in Standing Nanowires with 3D Fluorescence Confocal Microscopy.

    Science.gov (United States)

    Frederiksen, Rune; Tutuncuoglu, Gozde; Matteini, Federico; Martinez, Karen L; Fontcuberta I Morral, Anna; Alarcon-Llado, Esther

    2017-09-20

    Semiconductor nanowires are promising building blocks for next-generation photonics. Indirect proofs of large absorption cross sections have been reported in nanostructures with subwavelength diameters, an effect that is even more prominent in vertically standing nanowires. In this work we provide a three-dimensional map of the light around vertical GaAs nanowires standing on a substrate by using fluorescence confocal microscopy, where the strong long-range disruption of the light path along the nanowire is illustrated. We find that the actual long-distance perturbation is much larger in size than calculated extinction cross sections. While the size of the perturbation remains similar, the intensity of the interaction changes dramatically over the visible spectrum. Numerical simulations allow us to distinguish the effects of scattering and absorption in the nanowire leading to these phenomena. This work provides a visual understanding of light absorption in semiconductor nanowire structures, which is of high interest for solar energy conversion applications.

  12. Quantitative Light Fluorescence (QLF and Polarized White Light (PWL assessments of dental fluorosis in an epidemiological setting

    Directory of Open Access Journals (Sweden)

    Pretty Iain A

    2012-05-01

    Full Text Available Abstract Background To determine if a novel dual camera imaging system employing both polarized white light (PWL and quantitative light induced fluorescence imaging (QLF is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods. Methods Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3 participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software. Results Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92. Conclusions The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

  13. Improved power efficiency of blue fluorescent organic light-emitting diode with intermixed host structure

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Shouzhen; Zhang, Shiming; Zhang, Zhensong; Wu, Yukun; Wang, Peng; Guo, Runda; Chen, Yu; Qu, Dalong; Wu, Qingyang; Zhao, Yi, E-mail: yizhao@jlu.edu.cn; Liu, Shiyong

    2013-11-15

    High power efficiency (PE) p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-ph) based fluorescent blue organic light-emitting diode (OLED) is demonstrated by utilizing intermixed host (IH) structure. The PE outperforms those devices based on single host (SH), mixed host (MH), and double emitting layers (DELs). By further optimizing the intermixed layer, peak PE of the IH device is increased up to 8.7 lm/W (1.7 times higher than conventional SH device), which is the highest value among the DSA-ph based blue device reported so far. -- Highlights: • DSA-ph based blue fluorescent OLEDs are fabricated. • The intermixed host structure is first introduced into the blue devices. • Blue device with the highest power efficiency based on DSA-ph is obtained.

  14. Spectral signatures of fluorescence and light absorption to identify crude oils found in the marine environment

    Science.gov (United States)

    Baszanowska, E.; Otremba, Z.

    2014-08-01

    To protect the natural marine ecosystem, it is necessary to continuously enhance knowledge of environmental contamination, including oil pollution. Therefore, to properly track the qualitative and quantitative changes in the natural components of seawater, a description of the essential spectral features describing petroleum products is necessary. This study characterises two optically-different types of crude oils (Petrobaltic and Romashkino) - substances belonging to multi-fluorophoric systems. To obtain the spectral features of crude oils, the excitation-emission spectroscopy technique was applied. The fluorescence and light absorption properties for various concentrations of oils at a stabilised temperature are described. Both excitation-emission spectra (EEMs) and absorption spectra of crude oils are discussed. Based on the EEM spectra, both excitation end emission peaks for the wavelengthindependent fluorescence maximum (Exmax/ Emmax) - characteristic points for each type of oil - were identified and compared with the literature data concerning typical marine chemical structures.

  15. Emergence of White Organic Light-Emitting Diodes Based on Thermally Activated Delayed Fluorescence

    Directory of Open Access Journals (Sweden)

    Peng Xiao

    2018-02-01

    Full Text Available Recently, thermally activated delayed fluorescence (TADF organic light-emitting diodes (OLEDs have attracted both academic and industrial interest due to their extraordinary characteristics, such as high efficiency, low driving voltage, bright luminance, lower power consumption and potentially long lifetime. In this invited review, the fundamental concepts of TADF have been firstly introduced. Then, main approaches to realize WOLEDs based on TADF have been summarized. More specifically, the recent development of WOLEDs based on all TADF emitters, WOLEDs based on TADF and conventional fluorescence emitters, hybrid WOLEDs based on blue TADF and phosphorescence emitters and WOLEDs based on TADF exciplex host and phosphorescence dopants is highlighted. In particular, design strategies, device structures, working mechanisms and electroluminescent processes of the representative WOLEDs based on TADF are reviewed. Finally, challenges and opportunities for further enhancement of the performance of WOLEDs based on TADF are presented.

  16. Focused fluorescence excitation with time-reversed ultrasonically encoded light and imaging in thick scattering media

    International Nuclear Information System (INIS)

    Lai, Puxiang; Suzuki, Yuta; Xu, Xiao; Wang, Lihong V

    2013-01-01

    Scattering dominates light propagation in biological tissue, and therefore restricts both resolution and penetration depth in optical imaging within thick tissue. As photons travel into the diffusive regime, typically 1 mm beneath human skin, their trajectories transition from ballistic to diffusive due to the increased number of scattering events, which makes it impossible to focus, much less track, photon paths. Consequently, imaging methods that rely on controlled light illumination are ineffective in deep tissue. This problem has recently been addressed by a novel method capable of dynamically focusing light in thick scattering media via time reversal of ultrasonically encoded (TRUE) diffused light. Here, using photorefractive materials as phase conjugate mirrors, we show a direct visualization and dynamic control of optical focusing with this light delivery method, and demonstrate its application for focused fluorescence excitation and imaging in thick turbid media. These abilities are increasingly critical for understanding the dynamic interactions of light with biological matter and processes at different system levels, as well as their applications for biomedical diagnosis and therapy. (letter)

  17. Localization of fluorescently labeled structures in frozen-hydrated samples using integrated light electron microscopy.

    Science.gov (United States)

    Faas, F G A; Bárcena, M; Agronskaia, A V; Gerritsen, H C; Moscicka, K B; Diebolder, C A; van Driel, L F; Limpens, R W A L; Bos, E; Ravelli, R B G; Koning, R I; Koster, A J

    2013-03-01

    Correlative light and electron microscopy is an increasingly popular technique to study complex biological systems at various levels of resolution. Fluorescence microscopy can be employed to scan large areas to localize regions of interest which are then analyzed by electron microscopy to obtain morphological and structural information from a selected field of view at nm-scale resolution. Previously, an integrated approach to room temperature correlative microscopy was described. Combined use of light and electron microscopy within one instrument greatly simplifies sample handling, avoids cumbersome experimental overheads, simplifies navigation between the two modalities, and improves the success rate of image correlation. Here, an integrated approach for correlative microscopy under cryogenic conditions is presented. Its advantages over the room temperature approach include safeguarding the native hydrated state of the biological specimen, preservation of the fluorescence signal without risk of quenching due to heavy atom stains, and reduced photo bleaching. The potential of cryo integrated light and electron microscopy is demonstrated for the detection of viable bacteria, the study of in vitro polymerized microtubules, the localization of mitochondria in mouse embryonic fibroblasts, and for a search into virus-induced intracellular membrane modifications within mammalian cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. OSL response bleaching of BeO samples, using fluorescent light and blue LEDs

    International Nuclear Information System (INIS)

    Groppo, Daniela Piai; Caldas, Linda V.E.

    2015-01-01

    The optically stimulated luminescence (OSL) is widely used as a dosimetric technique for many applications. In this work, the OSL response bleaching of BeO samples was studied. The samples were irradiated using a beta radiation source ( 90 Sr+ 90 Y); the bleaching treatments (fluorescent light and blue LEDs) were performed, and the results were compared. Various optical treatment time intervals were tested until reaching the complete bleaching of the OSL response. The best combination of the time interval and bleaching type was analyzed. (author)

  19. Obstacles and opportunities in the commercialization of the solid-state-electronic fluorescent-lighting ballast

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.; Marcus, A.A.; Campbell, R.S.; Sommers, P.; Skumatz, L.; Berk, B.; Petty, P.; Eschbach, C.

    1981-10-01

    The Solid State Ballast (SSB) Program, aimed at improving the efficiency of fluorescent lights, is described. The first generation of solid state electronic ballasts has been developed and the technology has been transferred to the private sector. This report examines the opportunities for rapid dissemination of this technology into the marketplace. It includes a description of product characteristics and their influence on the commercialization of the SSB, a description of the technology delivery system presently used by the ballast industry, an analysis of the market for SSB, and identification of some high-leverage opportunities to accelerate the commercialization process. (MCW)

  20. Compact Fluorescent Lighting in America: Lessons Learned on the Way to Market

    Energy Technology Data Exchange (ETDEWEB)

    Sandahl, Linda J.; Gilbride, Theresa L.; Ledbetter, Marc R.; Steward, Heidi E.; Calwell, Chris

    2006-05-22

    This report describes the history of compact fluorescent lamps (CFLs) in America. CFLs were introduced in the 1970s; however, it has taken more than 20 years for them to gain widespread recognition in the U.S. residential lighting market. This report reviews the development of CFLs, efforts to increase market acceptance of them, and barriers to that acceptance. Lessons to be learned from this study of CFLs are identified in hopes of assisting future market introduction efforts for other promising energy-efficient technologies. This report was prepared by the Pacific Northwest National Laboratory for the U.S. Department of Energy’s Office of Building Technologies, Emerging Technologies Program.

  1. OSL response bleaching of BeO samples, using fluorescent light and blue LEDs

    International Nuclear Information System (INIS)

    Groppo, D P; Caldas, L V E

    2016-01-01

    The optically stimulated luminescence (OSL) is widely used as a dosimetric technique for many applications. In this work, the OSL response bleaching of BeO samples was studied. The samples were irradiated using a beta radiation source ("9"0Sr+"9"0Y); the bleaching treatments (fluorescent light and blue LEDs) were performed, and the results were compared. Various optical treatment time intervals were tested until reaching the complete bleaching of the OSL response. The best combination of the time interval and bleaching type was analyzed. (paper)

  2. New fluorescent dipolar pyrazine derivatives for non-doped red organic light-emitting diodes

    International Nuclear Information System (INIS)

    Gao Baoxiang; Zhou Quanguo; Geng Yanhou; Cheng Yanxiang; Ma Dongge; Xie Zhiyuan; Wang Lixiang; Wang Fosong

    2006-01-01

    Dipolar fluorescent compounds containing electron-accepting pyrazine-2,3-dicarbonitrile and electron-donating arylamine moiety have been designed and synthesized. The optical and electrochemical properties of these compounds can be adjusted by changing π-bridge length and the donor (D) strength. Organic light-emitting devices based on these compounds are fabricated. Saturated red emission of (0.67, 0.33) and the external quantum efficiency as high as 1.41% have been demonstrated for one of these compounds

  3. Fluorescence photooxidation with eosin: a method for high resolution immunolocalization and in situ hybridization detection for light and electron microscopy

    Science.gov (United States)

    1994-01-01

    A simple method is described for high-resolution light and electron microscopic immunolocalization of proteins in cells and tissues by immunofluorescence and subsequent photooxidation of diaminobenzidine tetrahydrochloride into an insoluble osmiophilic polymer. By using eosin as the fluorescent marker, a substantial improvement in sensitivity is achieved in the photooxidation process over other conventional fluorescent compounds. The technique allows for precise correlative immunolocalization studies on the same sample using fluorescence, transmitted light and electron microscopy. Furthermore, because eosin is smaller in size than other conventional markers, this method results in improved penetration of labeling reagents compared to gold or enzyme based procedures. The improved penetration allows for three-dimensional immunolocalization using high voltage electron microscopy. Fluorescence photooxidation can also be used for high resolution light and electron microscopic localization of specific nucleic acid sequences by in situ hybridization utilizing biotinylated probes followed by an eosin-streptavidin conjugate. PMID:7519623

  4. Effect of light-emitting diode vs. fluorescent lighting on laying hens in aviary hen houses: Part 1 - Operational characteristics of lights and production traits of hens.

    Science.gov (United States)

    Long, H; Zhao, Y; Wang, T; Ning, Z; Xin, H

    2016-01-01

    Light-emitting diode (LED) lights are becoming more affordable for agricultural applications. Despite many lab-scale studies concerning impact of LED on poultry, little research has been documented under field production conditions, especially for laying hens. This 15-month field study was carried out to evaluate the effects of LED vs. fluorescent (FL) lights on laying hens (Dekalb white breed) using 4 (2 pairs) aviary hen houses each at a nominal capacity of 50,000 hens. The evaluation was done regarding operational characteristics of the lights and hen production traits. The results show that spatial distribution of the LED light was less uniform than that of the FL light. Light intensity of the LED light decreased by 27% after 3,360 h use but remained quite steady from 3,360 to 5,760 h use. Eleven out of 762 (1.44%) LED lamps (new at onset of the study) in the 2 houses failed during the 15-month experiment period. The neck area of the LED lamp was hottest, presumably the primary reason for the lamp failure as cracks were noticed in the neck region of all failed LED lamps. No differences were observed in egg weight, hen-day egg production, feed use, and mortality rate between LED and FL regimens. However, hens under the FL had higher eggs per hen housed and better feed conversion than those under the LED during 20 to 70 wk production (P Hens under the LED tended to have less feather uniformity and insulation than those under the FL (P hens under the LED showed a larger median avoidance distance than those under the FL at 36 wk age (P hens under the LED were more alert; but no difference at 60 wk age. More comparative research to quantify behavioral and production responses of different breeds of hens to LED vs. FL lighting seems warranted. © 2015 Poultry Science Association Inc.

  5. The health risks associated with energy efficient fluorescent, LEDs, and artificial lighting

    Science.gov (United States)

    Panahi, Allen

    2014-09-01

    With the phasing out of incandescent lamps in many countries, the introduction of new LED based light sources and luminaries sometimes raise the question of whether the spectral characteristics of the LED and other energy savings Fluorescent lights including the popular CFLs are suitable to replace the traditional incandescent lamps. These concerns are sometimes raised particularly for radiation emissions in the UV and Blue parts of the spectrum. This paper aims to address such concerns for the common `white light' sources typically used in household and other general lighting used in the work place. Recent studies have shown that women working the night shift have an increased probability of developing breast cancer. We like to report on the findings of many studies done by medical professionals, in particular the recent announcement of AMA in the US and many studies conducted in the UK, as well as the European community to increase public awareness on the long term health risks of the optical and opto-biological effects on the human health caused by artificial lighting.

  6. Imaging of human differentiated 3D neural aggregates using light sheet fluorescence microscopy

    Science.gov (United States)

    Gualda, Emilio J.; Simão, Daniel; Pinto, Catarina; Alves, Paula M.; Brito, Catarina

    2014-01-01

    The development of three dimensional (3D) cell cultures represents a big step for the better understanding of cell behavior and disease in a more natural like environment, providing not only single but multiple cell type interactions in a complex 3D matrix, highly resembling physiological conditions. Light sheet fluorescence microscopy (LSFM) is becoming an excellent tool for fast imaging of such 3D biological structures. We demonstrate the potential of this technique for the imaging of human differentiated 3D neural aggregates in fixed and live samples, namely calcium imaging and cell death processes, showing the power of imaging modality compared with traditional microscopy. The combination of light sheet microscopy and 3D neural cultures will open the door to more challenging experiments involving drug testing at large scale as well as a better understanding of relevant biological processes in a more realistic environment. PMID:25161607

  7. Imaging of human differentiated 3D neural aggregates using light sheet fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Emilio J Gualda

    2014-08-01

    Full Text Available The development of three dimensional cell cultures represents a big step for the better understanding of cell behavior and disease in a more natural like environment, providing not only single but multiple cell type interactions in a complex three dimensional matrix, highly resembling physiological conditions. Light sheet fluorescence microscopy is becoming an excellent tool for fast imaging of such three-dimensional biological structures. We demonstrate the potential of this technique for the imaging of human differentiated 3D neural aggregates in fixed and live samples, namely calcium imaging and cell death processes, showing the power of imaging modality compared with traditional microscopy. The combination of light sheet microscopy and 3D neural cultures will open the door to more challenging experiments involving drug testing at large scale as well as a better understanding of relevant biological processes in a more realistic environment.

  8. Effects of fluorescent lighting on in vitro micropropagation of Lemna minor

    Science.gov (United States)

    Somsri, Kollawat; Pinyopich, Pataradawn; Mohammed, Waleed S.

    2010-05-01

    The vegetative in vitro propagation of Lemna minor stain SING-4 exposed to two different types of fluorescent light sources, Philips TLD 36W/54 and Toshiba FL40T8BRF/36, was studied. The liquid culture medium contained 4.43gl-1 phytohormone-free full-strength Murashige & Skoog (MS) basal medium with vitamins, 30gl-1 sucrose, and 1gl-1 MES. The results showed that both plant cultures had undergone normal asexual reproduction with an exponential increase trend. Cultures exposed to Toshiba FL40T8BRF/36 reproduced at a slightly faster rate while expressing significantly greener foliage (leaf color chart shade No.8), which indicates the presence of more chlorophyll, than cultures exposed to Philips TLD 36W/54 (leaf color chart shade No.4). The data obtained from our experiment reveals that light emitted from Toshiba FL40T8BRF/36 produces healthier and higher quality cultures.

  9. Highly efficient deep-blue organic light emitting diode with a carbazole based fluorescent emitter

    Science.gov (United States)

    Sahoo, Snehasis; Dubey, Deepak Kumar; Singh, Meenu; Joseph, Vellaichamy; Thomas, K. R. Justin; Jou, Jwo-Huei

    2018-04-01

    High efficiency deep-blue emission is essential to realize energy-saving, high-quality display and lighting applications. We demonstrate here a deep-blue organic light emitting diode using a novel carbazole based fluorescent emitter 7-[4-(diphenylamino)phenyl]-9-(2-ethylhexyl)-9H-carbazole-2-carbonitrile (JV234). The solution processed resultant device shows a maximum luminance above 1,750 cd m-2 and CIE coordinates (0.15,0.06) with a 1.3 lm W-1 power efficiency, 2.0 cd A-1 current efficiency, and 4.1% external quantum efficiency at 100 cd m-2. The resulting deep-blue emission enables a greater than 100% color saturation. The high efficiency may be attributed to the effective host-to-guest energy transfer, suitable device architecture facilitating balanced carrier injection and low doping concentration preventing efficiency roll-off caused by concentration quenching.

  10. A very thin light sheet technique used to investigate meniscus shapes by laser induced fluorescence

    International Nuclear Information System (INIS)

    Khan, M.A.

    2003-01-01

    In this paper a light sheet technique is described to accurately (50 μm) measure meniscus profiles in film formation problems. The use of a slit to create the thin (0.1 mm) laser sheet makes the technique easy to implement, and allows tunable sheet thickness. The low light intensity obtained through the slit is compensated by the induced fluorescence of the tested fluid, which provides good picture contrast. After video recording through a microscope, the actual meniscus is recovered by image processing and proper calibration. The efficiency of the technique is demonstrated on a coating flow experiment. Due to its good accuracy and ease of use, this technique is expected to provide useful quantitative information about meniscus problems, in particular for the validation of computational fluid dynamics CFD solutions of coating flows. (author)

  11. Use of quantitative light-induced fluorescence to monitor tooth whitening

    Science.gov (United States)

    Amaechi, Bennett T.; Higham, Susan M.

    2001-04-01

    The changing of tooth shade by whitening agents occurs gradually. Apart from being subjective and affected by the conditions of the surroundings, visual observation cannot detect a very slight change in tooth color. An electronic method, which can communicate the color change quantitatively, would be more reliable. Quantitative Light- induced Fluorescence (QLF) was developed to detect and assess dental caries based on the phenomenon of change of autofluorescence of a tooth by demineralization. However, stains on the tooth surface exhibit the same phenomenon, and therefore QLF can be used to measure the percentage fluorescence change of stained enamel with respect to surrounding unstained enamel. The present study described a technique of assessing the effect of a tooth-whitening agent using QLF. This was demonstrated in two experiments in which either wholly or partially stained teeth were whitened by intermittent immersion in sodium hypochlorite. Following each immersion, the integrated fluorescence change due to the stain was quantified using QLF. In either situation, the value of (Delta) Q decreased linearly as the tooth regained its natural shade. It was concluded that gradual changing of the shade of discolored teeth by a whitening agent could be quantified using QLF.

  12. Effects of light-emitting diode light v. fluorescent light on growing performance, activity levels and well-being of non-beak-trimmed W-36 pullets.

    Science.gov (United States)

    Liu, K; Xin, H; Settar, P

    2018-01-01

    More energy-efficient, readily dimmable, long-lasting and more affordable light-emitting diode (LED) lights are increasingly finding applications in poultry production facilities. Despite anecdotal evidence about the benefits of such lighting on bird performance and behavior, concrete research data were lacking. In this study, a commercial poultry-specific LED light (dim-to-blue, controllable correlated color temperature (CCT) from 4500 to 5300 K) and a typical compact fluorescent light (CFL) (soft white, CCT=2700 K) were compared with regards to their effects on growing performance, activity levels, and feather and comb conditions of non-beak-trimmed W-36 pullets during a 14-week rearing period. A total of 1280-day-old pullets in two successive batches, 640 birds each, were used in the study. For each batch, pullets were randomly assigned to four identical litter-floor rooms equipped with perches, two rooms per light regimen, 160 birds per room. Body weight, BW uniformity (BWU), BW gain (BWG) and cumulative mortality rate (CMR) of the pullets were determined every 2 weeks from day-old to 14 weeks of age (WOA). Activity levels of the pullets at 5 to 14 WOA were delineated by movement index. Results revealed that pullets under the LED and CFL lights had comparable BW (1140±5 g v. 1135±5 g, P=0.41), BWU (90.8±1.0% v. 91.9±1.0%, P=0.48) and CMR (1.3±0.6% v. 2.7±0.6%, P=0.18) at 14 WOA despite some varying BWG during the rearing. Circadian activity levels of the pullets were higher under the LED light than under the CFL light, possibly resulting from differences in spectrum and/or perceived light intensity between the two lights. No feather damage or comb wound was apparent in either light regimen at the end of the rearing period. The results contribute to understanding the impact of emerging LED lights on pullets rearing which is a critical component of egg production.

  13. Strong antenna-enhanced fluorescence of a single light-harvesting complex shows photon anti-bunching

    NARCIS (Netherlands)

    Wientjes, E.; Renger, J.; Curto, A.G.; Cogdell, R.; Hulst, van N.F.

    2014-01-01

    The nature of the highly efficient energy transfer in photosynthetic light-harvesting complexes is a subject of intense research. Unfortunately, the low fluorescence efficiency and limited photostability hampers the study of individual light-harvesting complexes at ambient conditions. Here we

  14. In Vivo Lighted Fluorescence via Fenton Reaction: Approach for Imaging of Hydrogen Peroxide in Living Systems.

    Science.gov (United States)

    Liu, Changhui; Chen, Weiju; Qing, Zhihe; Zheng, Jing; Xiao, Yue; Yang, Sheng; Wang, Lili; Li, Yinhui; Yang, Ronghua

    2016-04-05

    By virtue of its high sensitivity and rapidity, Fenton reaction has been demonstrated as a powerful tool for in vitro biochemical analysis; however, in vivo applications of Fenton reaction still remain to be exploited. Herein, we report, for the first time, the design, formation and testing of Fenton reaction for in vivo fluorescence imaging of hydrogen peroxide (H2O2). To realize in vivo fluorescence imaging of H2O2 via Fenton reaction, a functional nanosphere, Fc@MSN-FDNA/PTAD, is fabricated from mesoporous silica nanoparticle (MSN), a Fenton reagent of ferrocene (Fc), ROX-labeled DNA (FDNA), and a cationic perylene derivative (PTAD). The ferrocene molecules are locked in the pore entrances of MSN, and exterior of MSN is covalently immobilized with FDNA. As a key part, PTAD acts as not only the gatekeeper of MSN but also the efficient quencher of ROX. H2O2 can permeate into the nanosphere and react with ferrocene to product hydroxyl radical (·OH) via Fenton reaction, which cleaves FDNA to detach ROX from PTAD, thus in turn, lights the ROX fluorescence. Under physiological condition, H2O2 can be determined from 5.0 nM to 1.0 μM with a detection limit of 2.4 nM. Because of the rapid kinetics of Fenton reaction and high specificity for H2O2, the proposed method meets the requirement for real applications. The feasibility of Fc@MSN-FDNA/PTAD for in vivo applications is demonstrated for fluorescence imaging of exogenous and endogenous H2O2 in cells and mice. We expect that this work will not only contribute to the H2O2-releated studies but also open up a new way to exploit in vivo Fenton reaction for biochemical research.

  15. Compact fluorescent lighting in Wisconsin: elevated atmospheric emission and landfill deposition post-EISA implementation.

    Science.gov (United States)

    Arendt, John D; Katers, John F

    2013-07-01

    The majority of states in the USA, including Wisconsin, have been affected by elevated air, soil and waterborne mercury levels. Health risks associated with mercury increase from the consumption of larger fish species, such as Walleye or Pike, which bio-accumulate mercury in muscle tissue. Federal legislation with the 2011 Mercury and Air Toxics Standards and the Wisconsin legislation on mercury, 2009 Wisconsin Act 44, continue to aim at lowering allowable levels of mercury emissions. Meanwhile, mercury-containing compact fluorescent lights (CFL) sales continue to grow as businesses and consumers move away from energy intensive incandescent light bulbs. An exchange in pollution media is occurring as airborne mercury emissions from coal-burning power plants, the largest anthropogenic source of mercury, are being reduced by lower energy demand and standards, while more universal solid waste containing mercury is generated each time a CFL is disposed. The treatment of CFLs as a 'universal waste' by the Environmental Protection Agency (EPA) led to the banning of non-household fluorescent bulbs from most municipal solid waste. Although the EPA encourages recycling of bulbs, industry currently recycles fluorescent lamps and CFLs at a rate of only 29%. Monitoring programs at the federal and state level have had only marginal success with industrial and business CFL recycling. The consumer recycling rate is even lower at only 2%. A projected increase in residential CFL use in Wisconsin owing to the ramifications of the Energy Independence and Security Act of 2007 will lead to elevated atmospheric mercury and landfill deposition in Wisconsin.

  16. Exposure to 4100K fluorescent light elicits sex specific transcriptional responses in Xiphophorus maculatus skin.

    Science.gov (United States)

    Boswell, William T; Boswell, Mikki; Walter, Dylan J; Navarro, Kaela L; Chang, Jordan; Lu, Yuan; Savage, Markita G; Shen, Jianjun; Walter, Ronald B

    2018-06-01

    It has been reported that exposure to artificial light may affect oxygen intake, heart rate, absorption of vitamins and minerals, and behavioral responses in humans. We have reported specific gene expression responses in the skin of Xiphophorus fish after exposure to ultraviolet light (UV), as well as, both broad spectrum and narrow waveband visible light. In regard to fluorescent light (FL), we have shown that male X. maculatus exposed to 4100K FL (i.e. "cool white") rapidly suppress transcription of many genes involved with DNA replication and repair, chromosomal segregation, and cell cycle progression in skin. We have also detailed sex specific transcriptional responses of Xiphophorus skin after exposure to UVB. However, investigation of gender differences in global gene expression response after exposure to 4100K FL has not been reported, despite common use of this FL source for residential, commercial, and animal facility illumination. Here, we compare RNA-Seq results analyzed to assess changes in the global transcription profiles of female and male X. maculatus skin in response to 4100K FL exposure. Our results suggest 4100K FL exposure incites a sex-biased genetic response including up-modulation of inflammation in females and down modulation of DNA repair/replication in males. In addition, we identify clusters of genes that become oppositely modulated in males and females after FL exposure that are principally involved in cell death and cell proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Drug quantification in turbid media by fluorescence imaging combined with light-absorption correction using white Monte Carlo simulations

    DEFF Research Database (Denmark)

    Xie, Haiyan; Liu, Haichun; Svenmarker, Pontus

    2011-01-01

    Accurate quantification of photosensitizers is in many cases a critical issue in photodynamic therapy. As a noninvasive and sensitive tool, fluorescence imaging has attracted particular interest for quantification in pre-clinical research. However, due to the absorption of excitation and emission...... in vivo by the fluorescence imaging technique. In this paper we present a novel approach to compensate for the light absorption in homogeneous turbid media both for the excitation and emission light, utilizing time-resolved fluorescence white Monte Carlo simulations combined with the Beer-Lambert law......-absorption correction and absolute fluorophore concentrations. These results suggest that the technique potentially provides the means to quantify the fluorophore concentration from fluorescence images. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE)....

  18. Consumer preferences and willingness to pay for compact fluorescent lighting: Policy implications for energy efficiency promotion in Saint Lucia

    International Nuclear Information System (INIS)

    Reynolds, Travis; Kolodinsky, Jane; Murray, Byron

    2012-01-01

    This article examines consumer willingness to pay for energy-saving compact fluorescent light bulbs using the results of a stated preferences study conducted in the Caribbean island nation of Saint Lucia. Geographic location, low income status, and age are found to affect willingness-to-pay for compact fluorescent lighting, while higher income status and other demographic variables appear to have minimal or no significant impacts. Energy efficiency knowledge is associated with increased willingness-to-pay for energy-efficient bulbs and with increased use of compact fluorescent lighting. Contrary to theoretical expectations, past purchase of compact fluorescent bulbs is found to have no impact on self-reported willingness to pay. We hypothesize that this null result is due to the recent emergence of low-cost, low-quality compact fluorescent bulbs in the Saint Lucian lighting market, which may be negatively influencing consumers' preferences and expectations regarding energy-efficient lighting. Findings support the argument that government-sponsored education and subsidy programs will likely result in increased use of energy-saving technologies in Saint Lucia. But such behavioral changes may not be sustained in the long run unless low quality bulbs – the “lemons” of the compact fluorescent lighting market – can be clearly identified by consumers. - Highlights: ▶ We model how knowledge, attitudes, and past purchase affect CFL adoption. ▶ Saint Lucian consumers have some knowledge of and favorable attitudes toward CFLs. ▶ Energy efficiency knowledge increases stated willingness-to-pay (WTP) for CFLs. ▶ Past purchase does not increase WTP; low-quality ‘lemons’ may influence consumers. ▶ Policy can lower consumer risks in lighting markets where low quality bulbs exist.

  19. Sub-clinical middle ear malfunctions in elderly patients; prevalence ...

    African Journals Online (AJOL)

    ... absent acoustic reflex. Keywords: Middle ear malfunctions, elderly patients. ... hearing loss, had audiometric changes suggestive of such. We regarded such .... predictors of silent middle ear malfunction (control for Age and Sex). Variable.

  20. Highly efficient red fluorescent organic light-emitting diodes by sorbitol-doped PEDOT:PSS

    Science.gov (United States)

    Zheng, Yan-Qiong; Yu, Jun-Le; Wang, Chao; Yang, Fang; Wei, Bin; Zhang, Jian-Hua; Zeng, Cheng-Hui; Yang, Yang

    2018-06-01

    This work shows a promising approach to improve device performance by optimizing the electron transport and hole injection layers for tetraphenyldibenzoperiflanthene (DBP):rubrene-based red fluorescent organic light-emitting diodes (OLEDs). We compared the effect of two electron transport layers (ETLs), and found that the rubrene/bathophenanthroline (Bphen) ETL-based OLED showed a much higher external quantum efficiency (EQE) (4.67%) than the Alq3 ETL-based OLED (EQE of 3.08%). The doping ratio of DBP in rubrene was tuned from 1.0 wt% to 4.5 wt%, and the 1.5 wt%-DBP:rubrene-based OLED demonstrated the highest EQE of 5.24% and lowest turn-on voltage of 2.2 V. Atomic force microscopy images indicated that 1.5 wt% DBP-doped rubrene film exhibited a regular strip shape, and this regular surface was favorable to the hole and electron recombination in the emitting layer. Finally, the sorbitol-doped poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was used to further improve the EQE; doping with 6 wt% sorbitol achieved the highest current efficiency of 7.03 cd A‑1 and an EQE of 7.50%. The significantly enhanced performance implies that the hole injection is a limiting factor for DBP:rubrene-based red fluorescent OLEDs.

  1. UV light-emitting-diode photochemical mercury vapor generation for atomic fluorescence spectrometry.

    Science.gov (United States)

    Hou, Xiaoling; Ai, Xi; Jiang, Xiaoming; Deng, Pengchi; Zheng, Chengbin; Lv, Yi

    2012-02-07

    A new, miniaturized and low power consumption photochemical vapor generation (PVG) technique utilizing an ultraviolet light-emitting diode (UV-LED) lamp is described, and further validated via the determination of trace mercury. In the presence of formic acid, the mercury cold vapor is favourably generated from Hg(2+) solutions by UV-LED irradiation, and then rapidly transported to an atomic fluorescence spectrometer for detection. Optimum conditions for PVG and interferences from concomitant elements were investigated in detail. Under optimum conditions, a limit of detection (LOD) of 0.01 μg L(-1) was obtained, and the precision was better than 3.2% (n = 11, RSD) at 1 μg L(-1) Hg(2+). No obvious interferences from any common ions were evident. The methodology was successfully applied to the determination of mercury in National Research Council Canada DORM-3 fish muscle tissue and several water samples.

  2. Gating circuit for single photon-counting fluorescence lifetime instruments using high repetition pulsed light sources

    International Nuclear Information System (INIS)

    Laws, W.R.; Potter, D.W.; Sutherland, J.C.

    1984-01-01

    We have constructed a circuit that permits conventional timing electronics to be used in single photon-counting fluorimeters with high repetition rate excitation sources (synchrotrons and mode-locked lasers). Most commercial time-to-amplitude and time-to-digital converters introduce errors when processing very short time intervals and when subjected to high-frequency signals. This circuit reduces the frequency of signals representing the pulsed light source (stops) to the rate of detected fluorescence events (starts). Precise timing between the start/stop pair is accomplished by using the second stop pulse after a start pulse. Important features of our design are that the circuit is insensitive to the simultaneous occurrence of start and stop signals and that the reduction in the stop frequency allows the start/stop time interval to be placed in linear regions of the response functions of commercial timing electronics

  3. Active Appearance Segmentation for Intensity Inhomogeneity in Light Sheet Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Jensen, Casper Bo; Lyksborg, Mark; Hecksher-Sørensen, J.

    2016-01-01

    inhomogeneities which are often seen in Light Sheet Fluorescence Microscopy (LSFM) images. This robustness is achieved by modelling the appearance of an image as a regularized Normalized Gradient Field (rNGF). We perform two experiments to challenge the model. First it is tested using a repeated leave......Active Appearance Models (AAM) are used for annotating or segmenting shapes in biomedical images. Performance relies heavily on the image data used to train the AAM. In this paper we improve the generalization properties of the model by making it robust to slowly varying spatial intensity......-one-out approach on images with minimal imperfections where the left out images are corrupted by a simulated bias field and segmented using the AAM. Secondly we test the model on LSFM images with common acquisition problems. In both experiments the proposed approach outperforms the often used AAM implementation...

  4. Combined application of dynamic light scattering imaging and fluorescence intravital microscopy in vascular biology

    International Nuclear Information System (INIS)

    Kalchenko, V; Harmelin, A; Ziv, K; Addadi, Y; Madar-Balakirski, N; Neeman, M; Meglinski, I

    2010-01-01

    The dynamic light scattering imaging (DLSI) system combined with the conventional fluorescence intravital microscope (FIM) has been applied for the examination of blood and lymph vessels in the mouse ear in vivo. While the CCD camera can be shared by both techniques the combined application of DLSI and FIM allows rapid switching between the modalities. In current study temporal speckles fluctuations are used for rendering blood vessels structure and monitoring blood perfusion with the higher spatial resolution, whereas FIM provides the images of lymphatic vessels. The results clearly demonstrate that combined application of DLSI and FIM approaches provides synchronic in vivo images of blood and lymph vessels with higher contrast and specificity. The use of this new dual-modal diagnostic system is particularly important and has a great potential to significantly expand the capabilities of vascular diagnostics providing synchronic in vivo images of blood and lymph vessels

  5. White organic light emitting devices with hybrid emissive layers combining phosphorescence and fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Lei Gangtie; Chen Xiaolan; Wang Lei; Zhu Meixiang; Zhu Weiguo [Key Lab of Environmental-friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105 (China); Wang Liduo; Qiu Yong [Key Lab of Organic-Optoelectronics and Molecular Sciences of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China)], E-mail: lgt@xtu.edu.cn

    2008-05-21

    We fabricated a white organic light-emitting diode (WOLED) by hybrid emissive layers which combined phosphorescence with fluorescence. In this device, the thin layer of 4-(dicyanomethylene)-2-(t-butyl)-6-(1, 1, 7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran played the role of undoped red emissive layer which was inserted between two blue phosphorescence emissive layers. The blue phosphorescent dye was bis[(4, 6-difluorophenyl)-pyridinato-N, C{sup 2}] (picolinato) Ir(III), which was doped in the host material, N, N'-dicarbazolyl-1, 4-dimethene-benzene. The WOLED showed stable Commission Internationale de L'Eclairage coordinates and a high efficency of 9.6 cd A{sup -1} when the current density was 1.8 A m{sup -2}. The maximum luminance of the device achieved was 17 400 cd m{sup -2} when the current density was 3000 A m{sup -2}.

  6. Detection and Analysis of Enamel Cracks by Quantitative Light-induced Fluorescence Technology.

    Science.gov (United States)

    Jun, Mi-Kyoung; Ku, Hye-Min; Kim, Euiseong; Kim, Hee-Eun; Kwon, Ho-Keun; Kim, Baek-Il

    2016-03-01

    The ability to accurately detect tooth cracks and quantify their depth would allow the prediction of crack progression and treatment success. The aim of this in vitro study was to determine the capabilities of quantitative light-induced fluorescence (QLF) technology in the detection of enamel cracks. Ninety-six extracted human teeth were selected for examining naturally existing or suspected cracked teeth surfaces using a photocuring unit. QLF performed with a digital camera (QLF-D) images were used to assess the ability to detect enamel cracks based on the maximum fluorescence loss value (ΔFmax, %), which was then analyzed using the QLF-D software. A histologic evaluation was then performed in which the samples were sectioned and observed with the aid of a polarized light microscope. The relationship between ΔFmax and the histology findings was assessed based on the Spearman rank correlation. The sensitivity and specificity were calculated to evaluate the validity of using QLF-D to analyze enamel inner-half cracks and cracks extending to the dentin-enamel junction. There was a strong correlation between the results of histologic evaluations of enamel cracks and the ΔFmax value, with a correlation coefficient of 0.84. The diagnostic accuracy of QLF-D had a sensitivity of 0.87 and a specificity of 0.98 for enamel inner-half cracks and a sensitivity of 0.90 and a specificity of 1.0 for cracks extending to the dentin-enamel junction. These results indicate that QLF technology would be a useful clinical tool for diagnosing enamel cracks, especially given that this is a nondestructive method. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Clinical application of photodynamic medicine technology using light-emitting fluorescence imaging based on a specialized luminous source.

    Science.gov (United States)

    Namikawa, Tsutomu; Fujisawa, Kazune; Munekage, Eri; Iwabu, Jun; Uemura, Sunao; Tsujii, Shigehiro; Maeda, Hiromichi; Kitagawa, Hiroyuki; Fukuhara, Hideo; Inoue, Keiji; Sato, Takayuki; Kobayashi, Michiya; Hanazaki, Kazuhiro

    2018-04-04

    The natural amino acid 5-aminolevulinic acid (ALA) is a protoporphyrin IX (PpIX) precursor and a new-generation photosensitive substance that accumulates specifically in cancer cells. When indocyanine green (ICG) is irradiated with near-infrared (NIR) light, it shifts to a higher energy state and emits infrared light with a longer wavelength than the irradiated NIR light. Photodynamic diagnosis (PDD) using ALA and ICG-based NIR fluorescence imaging has emerged as a new diagnostic technique. Specifically, in laparoscopic examinations for serosa-invading advanced gastric cancer, peritoneal metastases could be detected by ALA-PDD, but not by conventional visible-light imaging. The HyperEye Medical System (HEMS) can visualize ICG fluorescence as color images simultaneously projected with visible light in real time. This ICG fluorescence method is widely applicable, including for intraoperative identification of sentinel lymph nodes, visualization of blood vessels in organ resection, and blood flow evaluation during surgery. Fluorescence navigation by ALA-PDD and NIR using ICG imaging provides good visualization and detection of the target lesions that is not possible with the naked eye. We propose that this technique should be used in fundamental research on the relationship among cellular dynamics, metabolic enzymes, and tumor tissues, and to evaluate clinical efficacy and safety in multicenter cooperative clinical trials.

  8. Shedding quantitative fluorescence light on novel regulatory mechanisms in skeletal biomedicine and biodentistry.

    Science.gov (United States)

    Lee, Ji-Won; Iimura, Tadahiro

    2017-02-01

    Digitalized fluorescence images contain numerical information such as color (wavelength), fluorescence intensity and spatial position. However, quantitative analyses of acquired data and their validation remained to be established. Our research group has applied quantitative fluorescence imaging on tissue sections and uncovered novel findings in skeletal biomedicine and biodentistry. This review paper includes a brief background of quantitative fluorescence imaging and discusses practical applications by introducing our previous research. Finally, the future perspectives of quantitative fluorescence imaging are discussed.

  9. A chlorophyll fluorescence-based method for the integrated characterization of the photophysiological response to light stress.

    Science.gov (United States)

    Serôdio, João; Schmidt, William; Frankenbach, Silja

    2017-02-01

    This work introduces a new experimental method for the comprehensive description of the physiological responses to light of photosynthetic organisms. It allows the integration in a single experiment of the main established manipulative chlorophyll fluorescence-based protocols. It enables the integrated characterization of the photophysiology of samples regarding photoacclimation state (generating non-sequential light-response curves of effective PSII quantum yield, electron transport rate or non-photochemical quenching), photoprotection capacity (running light stress-recovery experiments, quantifying non-photochemical quenching components) and the operation of photoinactivation and photorepair processes (measuring rate constants of photoinactivation and repair for different light levels and the relative quantum yield of photoinactivation). The new method is based on a previously introduced technique, combining the illumination of a set of replicated samples with spatially separated actinic light beams of different intensity, and the simultaneous measurement of the fluorescence emitted by all samples using an imaging fluorometer. The main novelty described here is the independent manipulation of light intensity and duration of exposure for each sample, and the control of the cumulative light dose applied. The results demonstrate the proof of concept for the method, by comparing the responses of cultures of Chlorella vulgaris acclimated to low and high light regimes, highlighting the mapping of light stress responses over a wide range of light intensity and exposure conditions, and the rapid generation of paired light-response curves of photoinactivation and repair rate constants. This approach represents a chlorophyll fluorescence 'protocol of everything', contributing towards the high throughput characterization of the photophysiology of photosynthetic organisms. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental

  10. Correlative and integrated light and electron microscopy of in-resin GFP fluorescence, used to localise diacylglycerol in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Peddie, Christopher J.; Blight, Ken; Wilson, Emma [Electron Microscopy Unit, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Melia, Charlotte [Electron Microscopy Unit, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Cell Biophysics Laboratory, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Department of Molecular Cell Biology, Leiden University Medical Centre, 2300 RC Leiden (Netherlands); Marrison, Jo [Department of Biology, The University of York, Heslington, York (United Kingdom); Carzaniga, Raffaella [Electron Microscopy Unit, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Domart, Marie-Charlotte [Electron Microscopy Unit, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Cell Biophysics Laboratory, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); O' Toole, Peter [Department of Biology, The University of York, Heslington, York (United Kingdom); Larijani, Banafshe [Cell Biophysics Laboratory, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom); Cell Biophysics Laboratory, Unidad de Biofísica (CSIC-UPV/EHU),Sarriena s/n, 48940 Leioa (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain); Collinson, Lucy M. [Electron Microscopy Unit, London Research Institute, Cancer Research UK, London WC2A 3LY (United Kingdom)

    2014-08-01

    Fluorescence microscopy of GFP-tagged proteins is a fundamental tool in cell biology, but without seeing the structure of the surrounding cellular space, functional information can be lost. Here we present a protocol that preserves GFP and mCherry fluorescence in mammalian cells embedded in resin with electron contrast to reveal cellular ultrastructure. Ultrathin in-resin fluorescence (IRF) sections were imaged simultaneously for fluorescence and electron signals in an integrated light and scanning electron microscope. We show, for the first time, that GFP is stable and active in resin sections in vacuo. We applied our protocol to study the subcellular localisation of diacylglycerol (DAG), a modulator of membrane morphology and membrane dynamics in nuclear envelope assembly. We show that DAG is localised to the nuclear envelope, nucleoplasmic reticulum and curved tips of the Golgi apparatus. With these developments, we demonstrate that integrated imaging is maturing into a powerful tool for accurate molecular localisation to structure. - Highlights: • GFP and mCherry fluorescence are preserved in heavy-metal stained mammalian cells embedded in resin • Fluorophores are stable and intensity is sufficient for detection in ultrathin sections • Overlay of separate LM and EM images from the same ultrathin section improves CLEM protein localisation precision • GFP is stable and active in the vacuum of an integrated light and scanning EM • Integrated light and electron microscopy shows new subcellular locations of the lipid diacylglycerol.

  11. Red-light absorption and fluorescence of phytochrome chromophores: A comparative theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Falklöf, Olle; Durbeej, Bo, E-mail: bodur@ifm.liu.se

    2013-11-08

    Highlights: • Calculation of red-light absorption and emission of phytochrome chromophores. • Comparison of TD-DFT and ab initio methods. • Pure functionals show better accuracy than hybrid functionals. - Abstract: Currently, much experimental effort is being invested in the engineering of phytochromes, a large superfamily of photoreceptor proteins, into fluorescent proteins suitable for bioimaging in the near-infrared regime. In this work, we gain insight into the potential of computational methods to contribute to this development by investigating how well representative quantum chemical methods reproduce recently recorded red-light absorption and emission maxima of synthetic derivatives of the bilin chromophores of phytochromes. Focusing on the performance of time-dependent density functional theory but using also the ab initio CIS(D), CC2 and CASPT2 methods, we explore how various methodological considerations influence computed spectra and find, somewhat surprisingly, that density functionals lacking exact exchange reproduce the experimental measurements with smaller errors than functionals that include exact exchange. Thus, for the important class of chromophores that bilins constitute, the widely established trend that hybrid functionals give more accurate excitation energies than pure functionals does not apply.

  12. Purely Organic Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes.

    Science.gov (United States)

    Wong, Michael Y; Zysman-Colman, Eli

    2017-06-01

    The design of thermally activated delayed fluorescence (TADF) materials both as emitters and as hosts is an exploding area of research. The replacement of phosphorescent metal complexes with inexpensive organic compounds in electroluminescent (EL) devices that demonstrate comparable performance metrics is paradigm shifting, as these new materials offer the possibility of developing low-cost lighting and displays. Here, a comprehensive review of TADF materials is presented, with a focus on linking their optoelectronic behavior with the performance of the organic light-emitting diode (OLED) and related EL devices. TADF emitters are cross-compared within specific color ranges, with a focus on blue, green-yellow, orange-red, and white OLEDs. Organic small-molecule, dendrimer, polymer, and exciplex emitters are all discussed within this review, as is their use as host materials. Correlations are provided between the structure of the TADF materials and their optoelectronic properties. The success of TADF materials has ushered in the next generation of OLEDs. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Automated detection of fluorescent cells in in-resin fluorescence sections for integrated light and electron microscopy.

    Science.gov (United States)

    Delpiano, J; Pizarro, L; Peddie, C J; Jones, M L; Griffin, L D; Collinson, L M

    2018-04-26

    Integrated array tomography combines fluorescence and electron imaging of ultrathin sections in one microscope, and enables accurate high-resolution correlation of fluorescent proteins to cell organelles and membranes. Large numbers of serial sections can be imaged sequentially to produce aligned volumes from both imaging modalities, thus producing enormous amounts of data that must be handled and processed using novel techniques. Here, we present a scheme for automated detection of fluorescent cells within thin resin sections, which could then be used to drive automated electron image acquisition from target regions via 'smart tracking'. The aim of this work is to aid in optimization of the data acquisition process through automation, freeing the operator to work on other tasks and speeding up the process, while reducing data rates by only acquiring images from regions of interest. This new method is shown to be robust against noise and able to deal with regions of low fluorescence. © 2018 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.

  14. Light stress effect and by nitrogen deficiency in plants of Petiveria alliacea measured with two-chlorophyll-fluorescence technique

    Science.gov (United States)

    Zuluaga, H.; Oviedo, A.; Solarte, Efrain; Pena, E. J.

    2004-10-01

    The chlorophyll fluorescence was studied in Petiveria alliacea plants exposed to different nitrogen concentrations and light radiation, the response was measured by two different forms; (1) measuring the photosynthetic efficiency with a pulse amplitude modulated fluorometro (PAM) emitted by a 650 nm diode and (2) measuring the fluorescence spectra caused by high power 452 nm diode with a SD2000 spectrometer. It was found out that the photosynthetic efficiency decreased in the plants exposed to high radiance and low nitrogen. Two chlorophyll fluorescence peaks were observed on 684 nm and 739 nm, the intensities in this wavelengths are inversely related with the light radiance. The correlation between the FIR and photosynthetic efficiency was very strong (r2 = -0.809, p Alliacea plants.

  15. Amphibious fluorescent carbon dots: one-step green synthesis and application for light-emitting polymer nanocomposites.

    Science.gov (United States)

    Zhou, Li; He, Benzhao; Huang, Jiachang

    2013-09-21

    A facile and green approach for the synthesis of amphibious fluorescent carbon dots (CDs) from natural polysaccharide is reported. Light-emitting polymer nanocomposites with excellent optical performance can be easily prepared by incorporation of the amphibious CDs into the polymer matrix.

  16. Do daily and seasonal trends in leaf solar induced fluorescence reflect changes in photosynthesis, growth or light exposure

    Czech Academy of Sciences Publication Activity Database

    Wyber, R.; Malenovský, Zbyněk; Ashcroft, M. B.; Osmond, C. B.; Robinson, S. A.

    2017-01-01

    Roč. 9, č. 6 (2017), č. článku 604. ISSN 2072-4292 Institutional support: RVO:67179843 Keywords : Light induced fluorescence transient * Photosynthetic active radiation * Photosynthetic yield * Pulse amplitude modulation * Remote sensing of vegetation Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 3.244, year: 2016

  17. Dynamic Response of Plant Chlorophyll Fluorescence to Light, Water and Nutrient Availability

    Science.gov (United States)

    Cendrero Mateo, M. D. P.; Moran, S. M.; Porcar-Castell, A.; Carmo-Silva, A. E.; Papuga, S. A.; Matveeva, M.; Wieneke, S.; Rascher, U.

    2014-12-01

    Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-surface. Spatial and temporal patterns of photosynthesis depend on dynamic plant-specific adaptation strategies to highly variable environmental conditions e.g. light, water, and nutrient availability. Chlorophyll fluorescence (ChF) has been proposed as a direct indicator of photosynthesis, and several studies have demonstrated its relationship with vegetation functioning at leaf and canopy level. In this study, two overarching questions about ChF were addressed: Q1) How water, nutrient and ambient light conditions determine the relationships between photosynthesis and ChF? Which is the optimum irradiance level for detecting water and nutrient deficit conditions with ChF?; Q2) What is the seasonal relationship between photosynthesis and ChF when nitrogen is the limiting factor? The results of this study indicated that when the differences between treatments (water or nitrogen) drive the relationship between photosynthesis and ChF, ChF has a direct relationship with photosynthesis. This study demonstrates that the light level at which plants were grown was optimum for detecting water and nutrient deficit with ChF. Further, the seasonal relation between photosynthesis and ChF with nitrogen stress was not a simple linear function due to the complex physiological relation between photosynthesis and ChF. Our study showed that at times in the season when nitrogen was sufficient and photosynthesis was highest, ChF decreased because these two processes compete for available energy. The results from this study demonstrated that ChF is a reliable indicator of plant stress and has great potential as a tool for better understand where, when, and how CO2 is exchanged between the land and atmosphere.

  18. Detection of Biomass in New York City Aerosols: Light Scattering and Optical Fluorescence Techniques

    Science.gov (United States)

    Niebauer, M.; Alimova, A.; Katz, A.; Xu, M.; Rudolph, E.; Steiner, J.; Alfano, R. R.

    2005-12-01

    Optical spectroscopy is an ideal method for detecting bacteria and spores in real time. Optical fluorescence spectroscopy examination of New York City aerosols is used to quantify the mass of bacteria spores present in air masses collected at 14 liters/minute onto silica fiber filters, and on silica fiber ribbons using an Environmental Beta Attenuation Monitor manufactured by MetOne Instruments configured for the PM2.5 fraction. Dipicolinic acid (DPA), a molecule found primarily in bacterial spores, is the most characteristic component of spores in trial experiments on over 200 collected aerosol samples. DPA is extracted from the spores using a heat bath and chelated with Terbium. The DPA:Tb is detected by measuring its characteristic fluorescence with emission bands at 490, 545 and 585 nm for 270 nm excitation. Light scattering also measures the size distribution for a number of a variety of bacteria - Bacillus subtilis (rod shaped), Staphylococcus aureus (spherical) and Pseudomonas aeruginosa (short rods) establishing that optical techniques satisfactorily distinguish populations based on their variable morphology. Size and morphology are obtained by applying a variation of the Gaussian Ray Approximation theory of anomalous diffraction theory to an analysis of the transmission spectra in the range of 0.4 to 1.0 microns. In test experiments, the refractive index of the inner spore core of Bacillus subtilis decreases from 1.51 to 1.39 while the spore radius enlarges from 0.38 to 0.6 micrometers. Optical determinations are verified by oil-immersion techniques and by scanning electron microscope measurements. Characterization of spores, germinating spore materials, and bacteria is considered vital to tracing bacteria in the environment, for the development of life-detection systems for planetary exploration, monitoring pathogens in environmental systems, and for the preparation of anti-terrorism strategies.

  19. Evaluation of mobile digital light-emitting diode fluorescence microscopy in Hanoi, Viet Nam.

    Science.gov (United States)

    Chaisson, L H; Reber, C; Phan, H; Switz, N; Nilsson, L M; Myers, F; Nhung, N V; Luu, L; Pham, T; Vu, C; Nguyen, H; Nguyen, A; Dinh, T; Nahid, P; Fletcher, D A; Cattamanchi, A

    2015-09-01

    Hanoi Lung Hospital, Hanoi, Viet Nam. To compare the accuracy of CellScopeTB, a manually operated mobile digital fluorescence microscope, with conventional microscopy techniques. Patients referred for sputum smear microscopy to the Hanoi Lung Hospital from May to September 2013 were included. Ziehl-Neelsen (ZN) smear microscopy, conventional light-emitting diode (LED) fluorescence microscopy (FM), CellScopeTB-based LED FM and Xpert(®) MTB/RIF were performed on sputum samples. The sensitivity and specificity of microscopy techniques were determined in reference to Xpert results, and differences were compared using McNemar's paired test of proportions. Of 326 patients enrolled, 93 (28.5%) were Xpert-positive for TB. The sensitivity of ZN microscopy, conventional LED FM, and CellScopeTB-based LED FM was respectively 37.6% (95%CI 27.8-48.3), 41.9% (95%CI 31.8-52.6), and 35.5% (95%CI 25.8-46.1). The sensitivity of CellScopeTB was similar to that of conventional LED FM (difference -6.5%, 95%CI -18.2 to 5.3, P = 0.33) and ZN microscopy (difference -2.2%, 95%CI -9.2 to 4.9, P = 0.73). The specificity was >99% for all three techniques. CellScopeTB performed similarly to conventional microscopy techniques in the hands of experienced TB microscopists. However, the sensitivity of all sputum microscopy techniques was low. Options enabled by digital microscopy, such as automated imaging with real-time computerized analysis, should be explored to increase sensitivity.

  20. Impact of various lighting source (incandescent, fluorescent, metal halide and high pressure sodium) on the production performance of chicken broilers

    International Nuclear Information System (INIS)

    Guffar, A.; Rahman, K.U.; Siddique, M.; Ahmad, F.

    2009-01-01

    Light is an important aspect of an animal's environment. Avian as well as mammalian species respond to light energy in a variety of ways. Recent research has indicated that light source may affect body weight, immune response, livability and health status. Broiler behavior is strongly affected by light sources. So the present project was designed to study the effect of light sources on the production performance of broilers. For this purpose, 500 day-old broilers purchased from the local market were reared for three days (adaptation period) in one group. Then these were randomly divided into five experimental groups each comprising of 100 birds. Group A was given 25 incandescent light (INC), Group B was given fluorescent light (FC), Group C was given metal halide light (MH), Group D was given high pressure sodium light (HPS) and Group E was given no light source (control). Performance trial in terms of measurement of weekly body weight, weekly feed consumption, feed conversion ratio (FCR), daily water consumption and mortality were checked. Among various lighting sources, MH proved the best light source regarding main parameters of production performance. (author)

  1. The growth and flowering of Hyacinthus orientalis L. Forced in pots under fluorescent light of different colours

    Directory of Open Access Journals (Sweden)

    Małgorzata Śmigielska

    2014-09-01

    Full Text Available Three hyacinth cultivars were forced under fluorescent lamps which emitted white, blue, green, yellow and red light. The plants started flowering in the first decade of February. The forcing period for two cultivars, ‘Anna Marie’ and ‘Blue Star’, was shortest under lamps emitting red light. The cultivar ‘White Pearl’ flowered equally early under lamps emitting red, white and blue light. The impact of light colour (wavelength on the leaf greenness index (SPAD was demonstrated. The photosynthetic activity of leaves was dependent on the cultivar. It was related both to the net rate of photosynthesis and the photosynthetic efficiency. Specific leaf area (SLA also depended on the cultivar. The level of SLA was related to the rate of photosynthesis and its efficiency. SLA was highest in all cultivars under green and yellow colour light. The chlorophyll content in the fresh and dry weight of leaves was highest under yellow light lamps.

  2. Numerical evaluation of droplet sizing based on the ratio of fluorescent and scattered light intensities (LIF/Mie technique)

    International Nuclear Information System (INIS)

    Charalampous, Georgios; Hardalupas, Yannis

    2011-01-01

    The dependence of fluorescent and scattered light intensities from spherical droplets on droplet diameter was evaluated using Mie theory. The emphasis is on the evaluation of droplet sizing, based on the ratio of laser-induced fluorescence and scattered light intensities (LIF/Mie technique). A parametric study is presented, which includes the effects of scattering angle, the real part of the refractive index and the dye concentration in the liquid (determining the imaginary part of the refractive index). The assumption that the fluorescent and scattered light intensities are proportional to the volume and surface area of the droplets for accurate sizing measurements is not generally valid. More accurate sizing measurements can be performed with minimal dye concentration in the liquid and by collecting light at a scattering angle of 60 deg. rather than the commonly used angle of 90 deg. Unfavorable to the sizing accuracy are oscillations of the scattered light intensity with droplet diameter that are profound at the sidescatter direction (90 deg.) and for droplets with refractive indices around 1.4.

  3. Comparing phototoxicity during the development of a zebrafish craniofacial bone using confocal and light sheet fluorescence microscopy techniques.

    Science.gov (United States)

    Jemielita, Matthew; Taormina, Michael J; Delaurier, April; Kimmel, Charles B; Parthasarathy, Raghuveer

    2013-12-01

    The combination of genetically encoded fluorescent proteins and three-dimensional imaging enables cell-type-specific studies of embryogenesis. Light sheet microscopy, in which fluorescence excitation is provided by a plane of laser light, is an appealing approach to live imaging due to its high speed and efficient use of photons. While the advantages of rapid imaging are apparent from recent work, the importance of low light levels to studies of development is not well established. We examine the zebrafish opercle, a craniofacial bone that exhibits pronounced shape changes at early developmental stages, using both spinning disk confocal and light sheet microscopies of fluorescent osteoblast cells. We find normal and aberrant opercle morphologies for specimens imaged with short time intervals using light sheet and spinning disk confocal microscopies, respectively, under equivalent exposure conditions over developmentally-relevant time scales. Quantification of shapes reveals that the differently imaged specimens travel along distinct trajectories in morphological space. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Photocatalytic disinfection of surfaces with copper doped Ti02 nanotube coatings illuminated by ceiling mounted fluorescent light

    Science.gov (United States)

    Koklic, Tilen; Pintarič, Štefan; Zdovc, Irena; Golob, Majda; Umek, Polona; Mehle, Alma; Dobeic, Martin; Štrancar, Janez

    2018-01-01

    High economic burden is associated with foodborne illnesses. Different disinfection methods are therefore employed in food processing industry; such as use of ultraviolet light or usage of surfaces with copper-containing alloys. However, all the disinfection methods currently in use have some shortcomings. In this work we show that copper doped TiO2 nanotubes deposited on existing surfaces and illuminated with ceiling mounted fluorescent lights can retard the growth of Listeria Innocua by 80% in seven hours of exposure to the fluorescent lights at different places in a food processing plant or in the laboratory conditions with daily reinocuation and washing. The disinfection properties of the surfaces seem to depend mainly on the temperature difference of the surface and the dew point, where for the maximum effectiveness the difference should be about 3 degrees celsius. The TiO2 nanotubes have a potential to be employed for an economical and continuous disinfection of surfaces. PMID:29768464

  5. Simple process of hybrid white quantum dot/organic light-emitting diodes by using quantum dot plate and fluorescence

    Science.gov (United States)

    Lee, Ho Won; Lee, Ki-Heon; Lee, Jae Woo; Kim, Jong-Hoon; Yang, Heesun; Kim, Young Kwan

    2015-02-01

    In this work, the simple process of hybrid quantum dot (QD)/organic light-emitting diode (OLED) was proposed to apply a white illumination light by using QD plate and organic fluorescence. Conventional blue fluorescent OLEDs were firstly fabricated and then QD plates of various concentrations, which can be controlled of UV-vis absorption and photoluminescence spectrum, were attached under glass substrate of completed blue devices. The suggested process indicates that we could fabricate the white device through very simple process without any deposition of orange or red organic emitters. Therefore, this work would be demonstrated that the potential simple process for white applications can be applied and also can be extended to additional research on light applications.

  6. Fluorescent Protein Voltage Probes Derived from ArcLight that Respond to Membrane Voltage Changes with Fast Kinetics

    Science.gov (United States)

    Han, Zhou; Jin, Lei; Platisa, Jelena; Cohen, Lawrence B.; Baker, Bradley J.; Pieribone, Vincent A.

    2013-01-01

    We previously reported the discovery of a fluorescent protein voltage probe, ArcLight, and its derivatives that exhibit large changes in fluorescence intensity in response to changes of plasma membrane voltage. ArcLight allows the reliable detection of single action potentials and sub-threshold activities in individual neurons and dendrites. The response kinetics of ArcLight (τ1-on ~10 ms, τ2-on ~ 50 ms) are comparable with most published genetically-encoded voltage probes. However, probes using voltage-sensing domains other than that from the Ciona intestinalis voltage sensitive phosphatase exhibit faster kinetics. Here we report new versions of ArcLight, in which the Ciona voltage-sensing domain was replaced with those from chicken, zebrafish, frog, mouse or human. We found that the chicken and zebrafish-based ArcLight exhibit faster kinetics, with a time constant (τ) less than 6ms for a 100 mV depolarization. Although the response amplitude of these two probes (8-9%) is not as large as the Ciona-based ArcLight (~35%), they are better at reporting action potentials from cultured neurons at higher frequency. In contrast, probes based on frog, mouse and human voltage sensing domains were either slower than the Ciona-based ArcLight or had very small signals. PMID:24312287

  7. Fluorescent protein voltage probes derived from ArcLight that respond to membrane voltage changes with fast kinetics.

    Directory of Open Access Journals (Sweden)

    Zhou Han

    Full Text Available We previously reported the discovery of a fluorescent protein voltage probe, ArcLight, and its derivatives that exhibit large changes in fluorescence intensity in response to changes of plasma membrane voltage. ArcLight allows the reliable detection of single action potentials and sub-threshold activities in individual neurons and dendrites. The response kinetics of ArcLight (τ1-on ~10 ms, τ2-on ~ 50 ms are comparable with most published genetically-encoded voltage probes. However, probes using voltage-sensing domains other than that from the Ciona intestinalis voltage sensitive phosphatase exhibit faster kinetics. Here we report new versions of ArcLight, in which the Ciona voltage-sensing domain was replaced with those from chicken, zebrafish, frog, mouse or human. We found that the chicken and zebrafish-based ArcLight exhibit faster kinetics, with a time constant (τ less than 6 ms for a 100 mV depolarization. Although the response amplitude of these two probes (8-9% is not as large as the Ciona-based ArcLight (~35%, they are better at reporting action potentials from cultured neurons at higher frequency. In contrast, probes based on frog, mouse and human voltage sensing domains were either slower than the Ciona-based ArcLight or had very small signals.

  8. Compact fluorescent lights and the impact of convenience and knowledge on household recycling rates.

    Science.gov (United States)

    Wagner, Travis P

    2011-06-01

    Increased energy costs, social marketing campaigns, public subsidies, and reduced retail prices have dramatically increased the number of compact fluorescent lights (CFLs) installed worldwide. CFLs provide many benefits, but they contain a very small amount of mercury. Given the billions of CFLs in use worldwide, they represent a significant source of mercury unless CFLs are recycled and the mercury recovered in an environmentally sound manner. In the state of Maine (northeast United States), despite mandated recycling of CFLs and availability of free CFL recycling, the household CFL recycling rate is very low. A study was undertaken to identify the primary factors responsible for low recycling. The first step was to survey householders who use CFLs. The 520 survey responses indicated that insufficient knowledge regarding recycling and inconvenience of the collection system are the two primary factors for the low recycling rate. To validate these findings, the second step was an examination of the current collection system to assess (a) the knowledge requirements necessary for recycling and (b) the convenience of the collection system. The results of this examination validated that knowledge requirements were excessively difficult to fulfill and the collection system is not sufficiently convenient. Based on these results, waste managers should focus on increasing convenience and simplifying access to information when designing or improving household collection and recycling of CFLs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Multicolor fluorescent light-emitting diodes based on cesium lead halide perovskite quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); Bai, Xue, E-mail: baix@jlu.edu.cn, E-mail: yuzhang@jlu.edu.cn; Sun, Chun; Zhang, Xiaoyu; Zhang, Yu, E-mail: baix@jlu.edu.cn, E-mail: yuzhang@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Zhang, Tieqiang [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)

    2016-08-08

    High quantum yield, narrow full width at half-maximum and tunable emission color of perovskite quantum dots (QDs) make this kind of material good prospects for light-emitting diodes (LEDs). However, the relatively poor stability under high temperature and air condition limits the device performance. To overcome this issue, the liquid-type packaging structure in combination with blue LED chip was employed to fabricate the fluorescent perovskite quantum dot-based LEDs. A variety of monochromatic LEDs with green, yellow, reddish-orange, and red emission were fabricated by utilizing the inorganic cesium lead halide perovskite quantum dots as the color-conversion layer, which exhibited the narrow full width at half-maximum (<35 nm), the relatively high luminous efficiency (reaching 75.5 lm/W), and the relatively high external quantum efficiency (14.6%), making it the best-performing perovskite LEDs so far. Compared to the solid state LED device, the liquid-type LED devices exhibited excellent color stability against the various working currents. Furthermore, we demonstrated the potential prospects of all-inorganic perovskite QDs for the liquid-type warm white LEDs.

  10. Multicolor fluorescent light-emitting diodes based on cesium lead halide perovskite quantum dots

    International Nuclear Information System (INIS)

    Wang, Peng; Bai, Xue; Sun, Chun; Zhang, Xiaoyu; Zhang, Yu; Zhang, Tieqiang

    2016-01-01

    High quantum yield, narrow full width at half-maximum and tunable emission color of perovskite quantum dots (QDs) make this kind of material good prospects for light-emitting diodes (LEDs). However, the relatively poor stability under high temperature and air condition limits the device performance. To overcome this issue, the liquid-type packaging structure in combination with blue LED chip was employed to fabricate the fluorescent perovskite quantum dot-based LEDs. A variety of monochromatic LEDs with green, yellow, reddish-orange, and red emission were fabricated by utilizing the inorganic cesium lead halide perovskite quantum dots as the color-conversion layer, which exhibited the narrow full width at half-maximum (<35 nm), the relatively high luminous efficiency (reaching 75.5 lm/W), and the relatively high external quantum efficiency (14.6%), making it the best-performing perovskite LEDs so far. Compared to the solid state LED device, the liquid-type LED devices exhibited excellent color stability against the various working currents. Furthermore, we demonstrated the potential prospects of all-inorganic perovskite QDs for the liquid-type warm white LEDs.

  11. Steady full colour white organic light-emitting devices consisting of an ultrathin red fluorescent layer

    International Nuclear Information System (INIS)

    Wen Wen; Yu Junsheng; Li Lu; Wang Jun; Jiang Yadong

    2009-01-01

    White organic light-emitting devices were fabricated using an ultrathin red fluorescent dye of 3-(dicyanomethylene)-5, 5-dimethyl-1-(4-dimethylamino-styryl)cyclohexene inserted in tris(8-quinolinolato) aluminium layer as a red and green emitting layer (EML) and a thin 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-diphenyl (DPVBi) layer as blue EML. A maximum power efficiency of 2.4 lm W -1 at 5.5 V and a maximum luminance of 16 690 cd m -2 at 18.5 V were obtained. Pure white emission with a good colour rendering index of 80 was achieved as low as 5 V. The Commission Internationale de l'Eclairage (CIE) coordinates near (0.330, 0.300) show a slight variation of (-0.020, +0.002) in a wide range of voltages. The achievement of full colour white emission at low-operation voltages and high-colour stability is attributed to the confining emission zone function of the thin EML and direct carrier trapping in the ultrathin layer.

  12. Steady full colour white organic light-emitting devices consisting of an ultrathin red fluorescent layer

    Energy Technology Data Exchange (ETDEWEB)

    Wen Wen; Yu Junsheng; Li Lu; Wang Jun; Jiang Yadong [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jsyu@uestc.edu.cn

    2009-01-07

    White organic light-emitting devices were fabricated using an ultrathin red fluorescent dye of 3-(dicyanomethylene)-5, 5-dimethyl-1-(4-dimethylamino-styryl)cyclohexene inserted in tris(8-quinolinolato) aluminium layer as a red and green emitting layer (EML) and a thin 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-diphenyl (DPVBi) layer as blue EML. A maximum power efficiency of 2.4 lm W{sup -1} at 5.5 V and a maximum luminance of 16 690 cd m{sup -2} at 18.5 V were obtained. Pure white emission with a good colour rendering index of 80 was achieved as low as 5 V. The Commission Internationale de l'Eclairage (CIE) coordinates near (0.330, 0.300) show a slight variation of (-0.020, +0.002) in a wide range of voltages. The achievement of full colour white emission at low-operation voltages and high-colour stability is attributed to the confining emission zone function of the thin EML and direct carrier trapping in the ultrathin layer.

  13. Enhancement of photorepair of ultraviolet-damage by preillumination with fluorescent light in cultured fish cells

    Energy Technology Data Exchange (ETDEWEB)

    Yasuhira, Shinji; Mitani, Hiroshi; Shima, Akihiro (Tokyo Univ. (Japan). Faculty of Science)

    1991-02-01

    Fluorescent light (FL) illumination of RBCF-1 cells derived from a goldfish, prior to 254 nm UV-irradiation enhanced their ability to photorepair. Cells were illuminated with FL for 1 h (29 W/m{sup 2}) and incubated for 8 h in the dark before being irradiated with 10 J/m{sup 2} UV. The surviving fraction of FL-treated cells after UV-irradiation rose about 7-fold (from 3 to 20%) by 20 min photorepair treatment with the same FL source, and 4-fold (from 1.6 to 6%) in the FL non-treated cells. Flow cytometric analysis showed that FL treatment did not affect the distribution of cell cycle phase at the time of UV-irradiation (8 h after FL treatment). Pyrimidine dimers induced by UV were measured by the use of UV endonuclease of micrococcus luteus and alkaline agarose gel electrophoresis. Initial yields of dimers after exposure to 10 J/m{sup 2} UV were almost the same (about 0.11 dimer/kb) between FL treated and non-treated cells. After 20 min photorepair treatment, {similar to} 70% of dimers were removed in the FL treated samples, while < 20% were removed in the non FL-treated ones. (author).

  14. Effect of fluorescent vs. poultry-specific light-emitting diode lights on production performance and egg quality of W-36 laying hens.

    Science.gov (United States)

    Liu, Kai; Xin, Hongwei; Sekhon, Jasreen; Wang, Tong

    2018-03-01

    More energy-efficient, durable, affordable, and dimmable light-emitting diode (LED) lights are finding applications in poultry production. However, data are lacking on controlled comparative studies concerning the impact of such lights during the pullet rearing and subsequent laying phase. This study evaluated two types of poultry-specific LED light (PS-LED) vs. fluorescent light (FL) with regards to their effects on hen laying performance. A total of 432 Hy-Line W-36 laying hens were tested in two batches using four environmental chambers (nine cages per chamber and 6 birds per cage) from 17 to 41 weeks of age (WOA). Dim-to-red PS-LED and warm-white FL were used in the laying phase. The hens had been reared under a dim-to-blue PS-LED or a warm-white FL from 1 to 16 WOA. The measured performance variables included 1) timing of sexual maturity, 2) egg production performance, 3) egg quality, and 4) egg yolk cholesterol. Results showed that the two types of light used during the laying phase had comparable performance responses for all response parameters (P > 0.05) with a few exceptions. Specifically, eggs laid from hens in the PS-LED treatment had lower shell thickness (P = 0.01) and strength (P = 0.03) than those in the FL treatment at 41 WOA. The two types of light used during the rearing phase did not influence the 17 to 41 WOA laying performance, except that hens reared under the PS-LED laid eggs with lower shell thickness (P = 0.02) at 32 WOA as compared to hens reared under the FL. This study demonstrates that the emerging poultry-specific LED lights yield comparable production performance and egg quality of W-36 laying hens to the traditional fluorescent lights.

  15. Comparative Study of Lettuce and Radish Grown Under Red and Blue Light-Emitting Diodes (LEDs) and White Fluorescent Lamps

    Science.gov (United States)

    Mickens, Matthew A.

    2012-01-01

    Growing vegetable crops in space will be an essential part of sustaining astronauts during long-term missions. To drive photosynthesis, red and blue light-emitting diodes (LEDs) have attracted attention because of their efficiency, longevity, small size, and safety. In efforts to optimize crop production, there have also been recent interests in analyzing the subtle effects of green light on plant growth, and to determine if it serves as a source of growth enhancement or suppression. A comparative study was performed on two short cycle crops of lettuce (Outredgeous) and radish (Cherry Bomb) grown under two light treatments. The first treatment being red and blue LEDs, and the second treatment consisting of white fluorescent lamps which contain a portion of green light. In addition to comparing biomass production, physiological characterizations were conducted on how the light treatments influence morphology, water use, chlorophyll content, and the production of A TP within plant tissues.

  16. Acclimation of shade-tolerant and light-resistant Tradescantia species to growth light: chlorophyll a fluorescence, electron transport, and xanthophyll content.

    Science.gov (United States)

    Mishanin, Vladimir I; Trubitsin, Boris V; Patsaeva, Svetlana V; Ptushenko, Vasily V; Solovchenko, Alexei E; Tikhonov, Alexander N

    2017-09-01

    In this study, we have compared the photosynthetic characteristics of two contrasting species of Tradescantia plants, T. fluminensis (shade-tolerant species), and T. sillamontana (light-resistant species), grown under the low light (LL, 50-125 µmol photons m -2  s -1 ) or high light (HL, 875-1000 µmol photons m -2  s -1 ) conditions during their entire growth period. For monitoring the functional state of photosynthetic apparatus (PSA), we measured chlorophyll (Chl) a emission fluorescence spectra and kinetics of light-induced changes in the heights of fluorescence peaks at 685 and 740 nm (F 685 and F 740 ). We also compared the light-induced oxidation of P 700 and assayed the composition of carotenoids in Tradescantia leaves grown under the LL and HL conditions. The analyses of slow induction of Chl a fluorescence (SIF) uncovered different traits in the LL- and HL-grown plants of ecologically contrasting Tradescantia species, which may have potential ecophysiological significance with respect to their tolerance to HL stress. The fluorometry and EPR studies of induction events in chloroplasts in situ demonstrated that acclimation of both Tradescantia species to HL conditions promoted faster responses of their PSA as compared to LL-grown plants. Acclimation of both species to HL also caused marked changes in the leaf anatomy and carotenoid composition (an increase in Violaxanthin + Antheraxantin + Zeaxanthin and Lutein pools), suggesting enhanced photoprotective capacity of the carotenoids in the plants grown in nature under high irradiance. Collectively, the results of the present work suggest that the mechanisms of long-term PSA photoprotection in Tradescantia are based predominantly on the light-induced remodeling of pigment-protein complexes in chloroplasts.

  17. Influence of opalescence and fluorescence properties on the light transmittance of resin composite as a function of wavelength.

    Science.gov (United States)

    Lee, Yong-Keun; Powers, John M

    2006-10-01

    To determine the influence of opalescence and fluorescence properties on the light transmittance of resin composites as a function of wavelength (410-750 nm). Spectral distribution of seven resin composites of A2 shade was measured according to the CIELAB color scale relative to the standard illuminant D65 in the reflectance and transmittance modes. Opalescence spectrum (OPS) was calculated as the subtraction spectrum (i.e., the spectrum measured in the transmittance mode subtracted at each wavelength from the spectrum measured in the reflectance mode). UV component of the illuminant was included and excluded to calculate the fluorescence spectrum (FLR and FLT in the reflectance and transmittance mode, respectively). Contrast ratio (CR) was calculated as the ratio of reflectance over a black background and over a white background. The total transmittance spectral distribution (TSD) value was used as the parameter to indicate masking ability of the resin composites over background color. Multiple regression analyses were performed among TSD and other optical parameters at the significance level of 0.05. In all the resin composites and wavelength range, correlation between CR and TSD was very high (r = -0.99). Correlations between each parameters varied by the wavelength range of fluorescence (410-500 nm) and no-fluorescence (510-750 nm). Correlation between OPS and TSD varied by the wavelength range (r = -0.86 to -0.94, Popalescence and fluorescence of resin composite varied by the wavelength.

  18. Efficient polymer white-light-emitting diodes with a single-emission layer of fluorescent polymer blend

    International Nuclear Information System (INIS)

    Niu Qiaoli; Xu Yunhua; Jiang Jiaxing; Peng Junbiao; Cao Yong

    2007-01-01

    Efficient polymer white-light-emitting diodes (WPLEDs) have been fabricated with a single layer of fluorescent polymer blend. The device structure consists of ITO/PEDOT/PVK/emissive layer/Ba/Al. The emissive layer is a blend of poly(9,9-dioctylfluorene) (PFO), phenyl-substituted PPV derivative (P-PPV) and a copolymer of 9,9-dioctylfluorene and 4,7-di(4-hexylthien-2-yl)-2,1,3-benzothiadiazole (PFO-DHTBT), which, respectively, emits blue, green and red light. The emission of pure and efficient white light was implemented by tuning the blend weight ratio of PFO: P-PPV: PFO-DHTBT to 96:4:0.4. The maximum current efficiency and luminance are, respectively, 7.6 cd/A at 6.7 V and 11930 cd/m 2 at 11.2 V. The CIE coordinates of white-light emission were stable with the drive voltages

  19. LED-FISH: Fluorescence microscopy based on light emitting diodes for the molecular analysis of Her-2/neu oncogene amplification

    Directory of Open Access Journals (Sweden)

    Vollmer Ekkehard

    2008-12-01

    Full Text Available Abstract Light emitting diodes (LED, which are available as small monochromatic light sources with characteristic features such as maximum illumination power combined with minimum energy consumption and extremely long lifespan have already proved as a highly potential low-cost alternative for specific diagnostic applications in clinical medicine such as tuberculosis fluorescence microscopy. Likewise, the most reliable evaluation of Her-2/neu (c-erbB2 gene amplification, which has been established in the last few years for routine diagnosis in clinical pathology as determinant towards Herceptin-based treatment of patients with breast cancer, is based on fluorescence in situ hybridization (FISH and corresponding high priced fluorescence equipment. In order to test the possibility to utilize the advantages of low-cost LED technology on FISH analysis of c-erbB2 gene expression for routine diagnostic purposes, the applicability of a standard bright field Carl Zeiss Axiostar Plus microscope equipped with a Fraen AFTER* LED Fluorescence Microscope Kit for the detection of Her-2/neu gene signals was compared to an advanced Nikon Eclipse 80i fluorescence microscope in combination with a conventional 100W mercury vapor lamp. Both microscopes were fitted with the same Quicam FAST CCD digital camera to unequivocally compare the quality of the captured images. C-erbB2 gene expression was analyzed in 30 different human tissue samples of primary invasive breast cancer, following formalin fixation and subsequent paraffin-embedding. The Her2/neu gene signals (green were identifiable in the tumor cells in all cases and images of equal quality were captured under almost identical conditions by 480 nm (blue LED module equipped standard Axiostar microscope as compared to conventional fluorescence microscopy. In this first attempt, these monochromatic LED elements proved in principle to be suitable for the detection of Her-2/neu gene expression by FISH. Thus, our own

  20. 40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Malfunction, startup, and shutdown..., startup, and shutdown regulations. (a) The following regulations are disapproved because they would permit... malfunctions and/or fail to sufficiently limit startup and shutdown exemptions to those periods where it is...

  1. Effects of water stress and light intensity on chlorophyll fluorescence parameters and pigments of Aloe vera L.

    Science.gov (United States)

    Hazrati, Saeid; Tahmasebi-Sarvestani, Zeinolabedin; Modarres-Sanavy, Seyed Ali Mohammad; Mokhtassi-Bidgoli, Ali; Nicola, Silvana

    2016-09-01

    Aloe vera L. is one of the most important medicinal plants in the world. In order to determine the effects of light intensity and water deficit stress on chlorophyll (Chl) fluorescence and pigments of A. vera, a split-plot in time experiment was laid out in a randomized complete block design with four replications in a research greenhouse. The factorial combination of three light intensities (50, 75 and 100% of sunlight) and four irrigation regimes (irrigation after depleting 20, 40, 60 and 80% of soil water content) were considered as main factors. Sampling time was considered as sub factor. The first, second and third samplings were performed 90, 180 and 270 days after imposing the treatments, respectively. The results demonstrated that the highest light intensity and the severe water stress decreased maximum fluorescence (Fm), variable fluorescence (Fv)/Fm, quantum yield of PSII photochemistry (ФPSII), Chl and photochemical quenching (qP) but increased non-photochemical quenching (NPQ), minimum fluorescence (F0) and Anthocyanin (Anth). Additionally, the highest Fm, Fv/Fm, ФPSII and qP and the lowest NPQ and F0 were observed when 50% of sunlight was blocked and irrigation was done after 40% soil water depletion. Irradiance of full sunlight and water deficit stress let to the photoinhibition of photosynthesis, as indicated by a reduced quantum yield of PSII, ФPSII, and qP, as well as higher NPQ. Thus, chlorophyll florescence measurements provide valuable physiological data. Close to half of total solar radiation and irrigation after depleting 40% of soil water content were selected as the most efficient treatments. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Noise analysis of a white-light supercontinuum light source for multiple wavelength confocal laser scanning fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Gail [Centre for Biophotonics, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR (United Kingdom)

    2005-08-07

    Intensity correlations of a Ti : sapphire, Kr/Ar and a white-light supercontinuum were performed to quantify the typical signal amplitude fluctuations and hence ascertain the comparative output stability of the white-light supercontinuum source for confocal laser scanning microscopy (CLSM). Intensity correlations across a two-pixel sample (n = 1000) of up to 98%, 95% and 94% were measured for the Ti : sapphire, Kr/Ar and white-light supercontinuum source, respectively. The white-light supercontinuum noise level is therefore acceptable for CLSM, with the added advantage of wider wavelength flexibility over traditional CLSM excitation sources. The relatively low-noise white-light supercontinuum was then used to perform multiple wavelength sequential CLSM of guinea pig detrusor to confirm the reliability of the system and to demonstrate system flexibility.

  3. The Slow Control System of the Auger Fluorescence Detectors

    Science.gov (United States)

    Barenthien, N.; Bethge, C.; Daumiller, K.; Gemmeke, H.; Kampert, K.-H.; Wiebusch, C.

    2003-07-01

    The fluorescence detector (FD) of the Pierre Auger experiment [1] comprises 24 telescopes that will be situated in 4 remote buildings in the Pampa Amarilla. It is planned to run the fluorescence detectors in absence of operators on site. Therefore, the main task of the Slow Control System (SCS) is to ensure a secure remote operation of the FD system. The Slow Control System works autonomously and continuously monitors those parameters which may disturb a secure operation. Commands from the data-acquisition system or the remote operator are accepted only if they do not violate safety rules that depend on the actual experimental conditions (e.g. high-voltage, wind-sp eed, light, etc.). In case of malfunctions (power failure, communication breakdown, ...) the SCS performs an orderly shutdown and subsequent startup of the fluorescence detector system. The concept and the implementation of the Slow Control System are presented.

  4. Absorption and fluorescence spectroscopic characterisation of the circadian blue-light photoreceptor cryptochrome from Drosophila melanogaster (dCry)

    Science.gov (United States)

    Shirdel, J.; Zirak, P.; Penzkofer, A.; Breitkreuz, H.; Wolf, E.

    2008-09-01

    The absorption and fluorescence behaviour of the circadian blue-light photoreceptor cryptochrome from Drosophila melanogaster (dCry) in a pH 8 aqueous buffer solution is studied. The flavin adenine dinucleotide (FAD) cofactor of dCry is identified to be present in its oxidized form (FAD ox), and the 5,10-methenyltetrahydrofolate (MTHF) cofactor is found to be hydrolyzed and oxidized to 10-formyldihydrofolate (10-FDHF). The absorption and the fluorescence behaviour of dCry is investigated in the dark-adapted (receptor) state, the light-adapted (signalling) state, and under long-time violet light exposure. Photo-excitation of FAD ox in dCry causes a reductive electron transfer to the formation of anionic FAD semiquinone (FAD rad - ), and photo-excitation of the generated FAD rad - causes an oxidative electron transfer to the back formation of FAD ox. In light adapted dCry a photo-induced equilibrium between FAD ox and FAD rad - exists. The photo-cycle dynamics of signalling state formation and recovery is discussed. Quantum yields of photo-induced signalling state formation of about 0.2 and of photo-induced back-conversion of about 0.2 are determined. A recovery of FAD rad - to FAD ox in the dark with a time constant of 1.6 min at room temperature is found.

  5. A Review of the Reflector Compact Fluorescent Lights Technology Procurement Program: Conclusions and Results

    Energy Technology Data Exchange (ETDEWEB)

    Sandahl, Linda J.; Gilbride, Theresa L.; Ledbetter, Marc R.; McCullough, Jeffrey J.

    2008-05-19

    This report describes a project sponsored by the U.S. Department of Energy (DOE) and implemented by the Pacific Northwest National Laboratory (PNNL), from 2000 to 2007 to improve the performance of reflector type (R-lamp) compact fluorescent lamps (CFLs) and increase their availability throughout the United States by means of a technology development and procurement strategy. In 2000, at the request of the U.S. Department of Energy’s Emerging Technologies Program and its predecessors, the Pacific Northwest National Laboratory undertook a technology procurement seeking R-CFLs that were specifically designed for use in ICAT recessed can fixtures and that met other minimum performance criteria including minimum light output and size restrictions (to ensure they fit in standard residential recessed cans). The technology procurement included two phases. In Phase I, requests for proposals (RFPs) were issued in October 2002 and five manufacturers responded with 12 lamp models. Eight of these models met the minimum requirements and passed the 6-hour short-term test in a simulated ICAT environment. These eight models were subjected to long-term tests of 6,000 or more hours in a simulated ICAT environment. Three of these models passed the short- and long-term tests and were promoted through the program website (www.pnl.gov/rlamps), press releases, and fliers. To increase the number of qualifying models, a second RFP was issued in June 2005. In April 2007, DOE announced that 16 reflector CFL (R-CFL) models by four manufacturers had met all the minimum requirements of Phase 2 of the R-CFL Technology Innovation Competition. PNNL developed both the criteria and the test apparatus design for Elevated Temperature Life Testing (ETLT), which has been included by DOE in its draft ENERGY STAR specifications for the reflector category of CFLs. PNNL promoted the winning lamps through a program website, press releases, and fliers as well as through program partners. PNNL also helped

  6. Insulin Pump Malfunction During Hospitalization: Two Case Reports.

    Science.gov (United States)

    Faulds, Eileen R; Wyne, Kathleen L; Buschur, Elizabeth O; McDaniel, Jodi; Dungan, Kathleen

    2016-06-01

    Insulin pump malfunctions and failures continue to occur; however, more severe malfunctions such as the "runaway pump" phenomenon are rarely reported. This article describes two cases of pump malfunction in which pump users appear to have received an unsolicited bolus of insulin resulting in severe episodes of hypoglycemia during hospitalization. Both cases of insulin pump malfunction occurred in the inpatient setting at a large academic medical center in the United States. An analysis of the corresponding insulin pump downloads was performed. The Food and Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE) database was searched for similar cases involving Medtronic (Northridge, CA) insulin pumps using the terms "pump," "infusion," "insulin AND malfunction AND Medtronic." The two cases described show remarkable similarities, each demonstrating a severe hypoglycemic event preceded by an infusion site change followed by an alarm. In both cases a rapid spraying of insulin was reported. The insulin pump downloads validated much of the patients' and medical staff's descriptions of events. The FDA's MAUDE database search revealed 425 cases meeting our search term criteria. All cases were reviewed. Seven cases were identified involving independent movement of the reservoir piston. The cases detailed are the first to describe an insulin pump malfunction of this nature in the hospital setting involving unsolicited insulin boluses leading to severe hypoglycemia. The cases are particularly compelling in that they were witnessed by medical personnel. Providers and patients should receive instruction education on the recognition and management of insulin pump malfunction.

  7. Efficiency improvement of flexible fluorescent and phosphorescent organic light emitting diodes by inserting a spin-coating buffer layer

    International Nuclear Information System (INIS)

    Tsai, Yu-Sheng; Wang, Shun-Hsi; Chen, Shen-Yaur; Su, Shin-Yuan; Juang, Fuh-Shyang

    2009-01-01

    We dissolved hole transport materials α-NPD and NPB in THF solvent, and spin-coated the α-NPD + THF or NPB + THF solution onto ITO anode surface to improve the luminance efficiency and lifetime of flexible fluorescent and phosphorescent organic light emitting diodes. Then the BCP and TPBi were employed as hole blocking layer (HBL) of phosphorescent device and its thickness was optimized. From the experimental results, the maximum luminance efficiency is 4.4 cd/A at 9 V of fluorescent device and 24.4 cd/A of phosphorescent device, respectively. Such an improvement in the device performance was attributed to the smoother surface and good contact between the interface of spin-coated HTL/ITO, the hole were effectively injected from the anode into the organic layer. And the deposited HTL can block excitons from diffusing into the anode to quench, thus improving the luminance efficiency and lifetime greatly.

  8. Fluorescence imaging with near-infrared light: new technological advances that enable in vivo molecular imaging

    International Nuclear Information System (INIS)

    Ntziachristos, Vasilis; Bremer, Christoph; Weissleder, Ralph

    2003-01-01

    A recent development in biomedical imaging is the non-invasive mapping of molecular events in intact tissues using fluorescence. Underpinning to this development is the discovery of bio-compatible, specific fluorescent probes and proteins and the development of highly sensitive imaging technologies for in vivo fluorescent detection. Of particular interest are fluorochromes that emit in the near infrared (NIR), a spectral window, whereas hemoglobin and water absorb minimally so as to allow photons to penetrate for several centimetres in tissue. In this review article we concentrate on optical imaging technologies used for non-invasive imaging of the distribution of such probes. We illuminate the advantages and limitations of simple photographic methods and turn our attention to fluorescence-mediated molecular tomography (FMT), a technique that can three-dimensionally image gene expression by resolving fluorescence activation in deep tissues. We describe theoretical specifics, and we provide insight into its in vivo capacity and the sensitivity achieved. Finally, we discuss its clinical feasibility. (orig.)

  9. Intrinsic fluorescence for cervical precancer detection using polarized light based in-house fabricated portable device

    Science.gov (United States)

    Meena, Bharat Lal; Singh, Pankaj; Sah, Amar Nath; Pandey, Kiran; Agarwal, Asha; Pantola, Chayanika; Pradhan, Asima

    2018-01-01

    An in-house fabricated portable device has been tested to detect cervical precancer through the intrinsic fluorescence from human cervix of the whole uterus in a clinical setting. A previously validated technique based on simultaneously acquired polarized fluorescence and polarized elastic scattering spectra from a turbid medium is used to extract the intrinsic fluorescence. Using a diode laser at 405 nm, intrinsic fluorescence of flavin adenine dinucleotide, which is the dominant fluorophore and other contributing fluorophores in the epithelium of cervical tissue, has been extracted. Different grades of cervical precancer (cervical intraepithelial neoplasia; CIN) have been discriminated using principal component analysis-based Mahalanobis distance and linear discriminant analysis. Normal, CIN I and CIN II samples have been discriminated from one another with high sensitivity and specificity at 95% confidence level. This ex vivo study with cervix of whole uterus samples immediately after hysterectomy in a clinical environment indicates that the in-house fabricated portable device has the potential to be used as a screening tool for in vivo precancer detection using intrinsic fluorescence.

  10. Shedding light on disulfide bond formation: engineering a redox switch in green fluorescent protein

    DEFF Research Database (Denmark)

    Østergaard, H.; Henriksen, A.; Hansen, Flemming G.

    2001-01-01

    To visualize the formation of disulfide bonds in living cells, a pair of redox-active cysteines was introduced into the yellow fluorescent variant of green fluorescent protein. Formation of a disulfide bond between the two cysteines was fully reversible and resulted in a >2-fold decrease...... in the intrinsic fluorescence. Inter conversion between the two redox states could thus be followed in vitro as well as in vivoby non- invasive fluorimetric measurements. The 1.5 Angstrom crystal structure of the oxidized protein revealed a disulfide bond- induced distortion of the beta -barrel, as well...... the physiological range for redox-active cysteines. In the cytoplasm of Escherichia coli, the protein was a sensitive probe for the redox changes that occur upon disruption of the thioredoxin reductive pathway....

  11. I and C functional test facility malfunction cause and effect

    International Nuclear Information System (INIS)

    Kwon, Kee Choon.

    1997-06-01

    The objective of I and C function test facility (FTF) is to validate newly developed digital control and protection algorithm, alarm reduction algorithm and the function of operator support system and so on. To realize transient and accident situation in the FTF, the result of the activation of malfunction should be similar to the situation of real nuclear power plants. In this technical report, describe the Group, Malfunction No., Description, Option, Recommendations, Considered in Subroutine, Limitations, Cause, and Effect of the malfunctions implemented in FTF. (author)

  12. Studies on artificial light type vegetation plant using fluorescent lamps. Keikoto wo mochiita jinko kogata shokubutsu kojo no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Iwao, K [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1991-11-01

    This paper describes the contents of studies carried out for four years on a fluorescent lamp type vegetation plant. The equipment consists of a chiller unit with 5 HP, a motive power board of three-phase 200 V/feeder with an annual power capacity of 20 kW at maximum, and a micro-computer to control the culture environmental conditions. Discussions were given on the equipment performance, profitability, production capacity for salads and lettuces, and related data. Although the system has some disadvantage in the economy, it provided effective results on the know-hows in culturing high-class vegetables and fruits under season-free and chemical-free conditions. Since the natural light is also required, the professional knowledges and know-hows in this area were incorporated in the development. Fluorescent lamps emitting three primary colors of red, green and blue were devised and used. Because insufficient light intensity would raise the temperature only up to 42{degree}C when the ambient temperature is 25{degree}C, a proximity illumination system was adopted, which provided 45KIx high light intensity as well as the working spectra over an wide area. Tomato cultivation has also become possible, which is an epoch-making success. The system yielded better than hydroponic cultivation in solar greenhouse of the same size. 11 refs., 16 figs., 2 tabs.

  13. "DNA Origami Traffic Lights" with a Split Aptamer Sensor for a Bicolor Fluorescence Readout.

    Science.gov (United States)

    Walter, Heidi-Kristin; Bauer, Jens; Steinmeyer, Jeannine; Kuzuya, Akinori; Niemeyer, Christof M; Wagenknecht, Hans-Achim

    2017-04-12

    A split aptamer for adenosine triphosphate (ATP) was embedded as a recognition unit into two levers of a nanomechanical DNA origami construct by extension and modification of selected staple strands. An additional optical module in the stem of the split aptamer comprised two different cyanine-styryl dyes that underwent an energy transfer from green (donor) to red (acceptor) emission if two ATP molecules were bound as target molecule to the recognition module and thereby brought the dyes in close proximity. As a result, the ATP as a target triggered the DNA origami shape transition and yielded a fluorescence color change from green to red as readout. Conventional atomic force microscopy (AFM) images confirmed the topology change from the open form of the DNA origami in the absence of ATP into the closed form in the presence of the target molecule. The obtained closed/open ratios in the absence and presence of target molecules tracked well with the fluorescence color ratios and thereby validated the bicolor fluorescence readout. The correct positioning of the split aptamer as the functional unit farthest away from the fulcrum of the DNA origami was crucial for the aptasensing by fluorescence readout. The fluorescence color change allowed additionally to follow the topology change of the DNA origami aptasensor in real time in solution. The concepts of fluorescence energy transfer for bicolor readout in a split aptamer in solution, and AFM on surfaces, were successfully combined in a single DNA origami construct to obtain a bimodal readout. These results are important for future custom DNA devices for chemical-biological and bioanalytical purposes because they are not only working as simple aptamers but are also visible by AFM on the single-molecule level.

  14. Improvement of graphite crystal analyzer for light elements on X-ray fluorescence holography measurement

    Science.gov (United States)

    Happo, Naohisa; Hada, Takuma; Kubota, Atsushi; Ebisu, Yoshihiro; Hosokawa, Shinya; Kimura, Koji; Tajiri, Hiroo; Matsushita, Tomohiro; Hayashi, Kouichi

    2018-05-01

    Using a graphite crystal analyzer, focused monochromatic fluorescent X-rays can be obtained on an X-ray fluorescence holography (XFH) measurement. To measure the holograms of elements lighter than Ti, we improved a cylindrical-type crystal analyzer and constructed a small C-shaped analyzer. Using the constructed C-shaped analyzer, a Ca Kα hologram of a fluorite single crystal was obtained, from which we reconstructed a clear atomic image. The XFH measurements for the K, Ca, and Sc elements become possible using the presently constructed analyzer.

  15. Surgical instrument biocontaminant fluorescence detection in ambient lighting conditions for hospital reprocessing and sterilization department (Conference Presentation)

    Science.gov (United States)

    Baribeau, François; Bubel, Annie; Dumont, Guillaume; Vachon, Carl; Lépine, André; Rochefort, Stéphane; Massicotte, Martin; Buteau-Vaillancourt, Louis; Gallant, Pascal; Mermut, Ozzy

    2017-03-01

    Hospitals currently rely on simple human visual inspection for assessing cleanliness of surgical instruments. Studies showed that surgical site infections are in part attributed to inadequate cleaning of medical devices. Standards groups recognize the need to objectively quantify the amount of residues on surgical instruments and establish guidelines. We developed a portable technology for the detection of contaminants on surgical instruments through fluorescence following cleaning. Weak fluorescence signals are usually detected in the obscurity only with the lighting of the excitation source. The key element of this system is that it works in ambient lighting conditions, a requirement to not disturb the normal workflow of hospital reprocessing facilities. A biocompatible fluorescent dye is added to the detergent and labels the proteins of organic residues. It is resistant to the harsh environment in a washer-disinfector. Two inspection devices have been developed with a 488nm laser as the excitation source: a handheld scanner and a tabletop station using spectral-domain and time-domain ambient light cancellation schemes. The systems are eye safe and equipped with image processing and interfacing software to provide visual or audible warnings to the operator based on a set of adjustable signal thresholds. Micron-scale residues are detected by the system which can also evaluate soil size and mass. Unlike swabbing, it can inspect whole tools in real-time. The technology has been validated in an independent hospital decontamination research laboratory. It also has potential applications in the forensics, agro-food, and space fields. Technical aspects and results will be presented and discussed.

  16. Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light.

    Science.gov (United States)

    Wang, Jun; Lu, Wei; Tong, Yuxin; Yang, Qichang

    2016-01-01

    Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m(-2)⋅s(-1) irradiance for a 16 h⋅d(-1) photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (A max) and photosynthetic rate (P n) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. P n and A max under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between P n and shoot dry weight accumulation.

  17. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta).

    Science.gov (United States)

    Wu, Huanyang

    2016-01-01

    Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation.

  18. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta

    Directory of Open Access Journals (Sweden)

    Huanyang Wu

    2016-01-01

    Full Text Available Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation.

  19. The Inherent Visible Light Signature of an Intense Underwater Ultraviolet Light Source Due to Combined Raman and Fluorescence Effects

    Science.gov (United States)

    2000-01-01

    Humans cannot see ultraviolet light. The blue-sensitive cones in the retina would respond weakly to ultraviolet wavelengths if exposed to them, but...545, 1992. 3. C. S. Yentsch, and D. A. Phinney, " Autofluorescence and Raman scattering in the marine underwater environment," Ocean Optics X, SPIE

  20. An optical and electrical study of full thermally activated delayed fluorescent white organic light-emitting diodes

    OpenAIRE

    Pereira, Daniel de Sa; dos Santos, Paloma L.; Ward, Jonathan S.; Data, Przemyslaw; Okazaki, Masato; Takeda, Youhei; Minakata, Satoshi; Bryce, Martin R.; Monkman, Andrew P.

    2017-01-01

    We report on the engineering of full thermally activated delayed fluorescence – based white organic light emitting diodes (W-OLEDs) composed of three emitters (2,7-bis(9,9-dimethyl-acridin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DDMA-TXO2), 2,7-bis(phenoxazin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DPO-TXO2) and 3,11-di(10H-phenoxazin-10-yl)dibenzo[a,j]phenazine (POZ-DBPHZ) in two different hosts. By controlling the device design through the study of the emission of DDMA-TXO2 and DP...

  1. Effect of irradiation with black light fluorescent lamp on coloration and hardness of strawberry [Fragaria ananassa] fruits

    International Nuclear Information System (INIS)

    Higashio, H.; Hirono, H.; Sato, F.; Tokuda, S.; Uragami, A.

    2009-01-01

    The effect of irradiation by black light fluorescent lamp on the coloration and hardness of detached strawberry fruits was studied. Only the coloring of fruits (var. Toyonoka) that had started to pigment was accelerated by lamp irradiation. Maintaining the irradiation distance and ambient temperature after treatment was very important to obtain the maximum effect, and the action of lamps was restricted to the irradiated parts. The accelerating effect of a lamp on coloration was observed in all 3 of other varieties examined, and in some varieties, the level of anthocyanin concentration in fruits was greater than that in ripening stage. However, the lamp did not affect the hardness of fruits

  2. Fluorescence and white light cystoscopy for detection of carcinoma in situ of the urinary bladder.

    NARCIS (Netherlands)

    Lerner, S.P.; Liu, H.; Wu, M.F.; Thomas, Y.K.; Witjes, J.A.

    2012-01-01

    OBJECTIVES: To understand the additional benefits of HAL compared with conventional cystoscopy at the patient level and to explore relationships of urine cytology and CIS. METHODS: We reanalyzed pooled data from 3 phase III studies comparing hexaminolevulinate (HAL, Hexvix) fluorescence cystoscopy

  3. Real-time endoscopic guidance using near-infrared fluorescent light for thoracic surgery

    Science.gov (United States)

    Venugopal, Vivek; Stockdale, Alan; Neacsu, Florin; Kettenring, Frank; Frangioni, John V.; Gangadharan, Sidharta P.; Gioux, Sylvain

    2013-03-01

    Lung cancer is the leading cause of cancer death in the United States, accounting for 28% of all cancer deaths. Standard of care for potentially curable lung cancer involves preoperative radiographic or invasive staging, followed by surgical resection. With recent adjuvant chemotherapy and radiation studies showing a survival advantage in nodepositive patients, it is crucial to accurately stage these patients surgically in order to identify those who may benefit. However, lymphadenectomy in lung cancer is currently performed without guidance, mainly due to the lack of tools permitting real-time, intraoperative identification of lymph nodes. In this study we report the design and validation of a novel, clinically compatible near-infrared (NIR) fluorescence thoracoscope for real-time intraoperative guidance during lymphadenectomy. A novel, NIR-compatible, clinical rigid endoscope has been designed and fabricated, and coupled to a custom source and a dual channel camera to provide simultaneous color and NIR fluorescence information to the surgeon. The device has been successfully used in conjunction with a safe, FDA-approved fluorescent tracer to detect and resect mediastinal lymph nodes during thoracic surgery on Yorkshire pigs. Taken together, this study lays the foundation for the clinical translation of endoscopic NIR fluorescence intraoperative guidance and has the potential to profoundly impact the management of lung cancer patients.

  4. The electronics in fluorescent bulbs and light emitting diodes (LED), rather than ultraviolet radiation, cause increased malignant melanoma incidence in indoor office workers and tanning bed users.

    Science.gov (United States)

    Milham, Samuel; Stetzer, Dave

    2018-07-01

    The epidemiology of cutaneous malignant melanoma (CMM) has a number of facets that do not fit with sunlight and ultraviolet light as the primary etiologic agents. Indoor workers have higher incidence and mortality rates of CMM than outdoor workers; CMM occurs in body locations never exposed to sunlight; CMM incidence is increasing in spite of use of UV blocking agents and small changes in solar radiation. Installation of two new fluorescent lights in the milking parlor holding area of a Minnesota dairy farm in 2015 caused an immediate drop in milk production. This lead to measurement of body amperage in humans exposed to modern non-incandescent lighting. People exposed to old and new fluorescent lights, light emitting diodes (LED) and compact fluorescent lights (CFL) had body amperage levels above those considered carcinogenic. We hypothesize that modern electric lighting is a significant health hazard, a carcinogen, and is causing increasing CMM incidence in indoor office workers and tanning bed users. These lights generate dirty electricity (high frequency voltage transients), radio frequency (RF) radiation, and increase body amperage, all of which have been shown to be carcinogenic. This could explain the failure of ultraviolet blockers to stem the malignant melanoma pandemic. Tanning beds and non-incandescent lighting could be made safe by incorporating a grounded Faraday cage which allows passage of ultraviolet and visible light frequencies and blocks other frequencies. Modern electric lighting should be fabricated to be electrically clean. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Automatic detection and analysis of nuclear plant malfunctions

    International Nuclear Information System (INIS)

    Bruschi, R.; Di Porto, P.; Pallottelli, R.

    1985-01-01

    In this paper a system is proposed, which performs dynamically the detection and analysis of malfunctions in a nuclear plant. The proposed method was developed and implemented on a Reactor Simulator, instead of on a real one, thus allowing a wide range of tests. For all variables under control, a simulation module was identified and implemented on the reactor on-line computer. In the malfunction identification phase all modules run separately, processing plant input variables and producing their output variable in Real-Time; continuous comparison of the computed variables with plant variables allows malfunction's detection. At this moment the second phase can occur: when a malfunction is detected, all modules are connected, except the module simulating the wrong variable, and a fast simulation is carried on, to analyse the consequences. (author)

  6. Startup, Shutdown, & Malfunction (SSM) Emissions at Industrial Facilities

    Science.gov (United States)

    EPA issued a final action to ensure states have plans in place that are fully consistent with the Clean Air Act and recent court decisions concerning startup, shutdown and malfunction (SSM) operations.

  7. Performance of a two-leaf light use efficiency model for mapping gross primary productivity against remotely sensed sun-induced chlorophyll fluorescence data.

    Science.gov (United States)

    Zan, Mei; Zhou, Yanlian; Ju, Weimin; Zhang, Yongguang; Zhang, Leiming; Liu, Yibo

    2018-02-01

    Estimating terrestrial gross primary production is an important task when studying the carbon cycle. In this study, the ability of a two-leaf light use efficiency model to simulate regional gross primary production in China was validated using satellite Global Ozone Monitoring Instrument - 2 sun-induced chlorophyll fluorescence data. The two-leaf light use efficiency model was used to estimate daily gross primary production in China's terrestrial ecosystems with 500-m resolution for the period from 2007 to 2014. Gross primary production simulated with the two-leaf light use efficiency model was resampled to a spatial resolution of 0.5° and then compared with sun-induced chlorophyll fluorescence. During the study period, sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model exhibited similar spatial and temporal patterns in China. The correlation coefficient between sun-induced chlorophyll fluorescence and monthly gross primary production simulated by the two-leaf light use efficiency model was significant (pproduction simulated by the two-leaf light use efficiency model were similar in spring and autumn in most vegetated regions, but dissimilar in winter and summer. The spatial variability of sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model was similar in spring, summer, and autumn. The proportion of spatial variations of sun-induced chlorophyll fluorescence and annual gross primary production simulated by the two-leaf light use efficiency model explained by ranged from 0.76 (2011) to 0.80 (2013) during the study period. Overall, the two-leaf light use efficiency model was capable of capturing spatial and temporal variations in gross primary production in China. However, the model needs further improvement to better simulate gross primary production in summer. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Subtle spectral effects accompanying the assembly of bacteriochlorophylls into cyclic light harvesting complexes revealed by high-resolution fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rätsep, Margus, E-mail: margus.ratsep@ut.ee; Pajusalu, Mihkel, E-mail: mihkel.pajusalu@ut.ee; Linnanto, Juha Matti, E-mail: juha.matti.linnanto@ut.ee [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia); Freiberg, Arvi, E-mail: arvi.freiberg@ut.ee [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia and Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu (Estonia)

    2014-10-21

    We have observed that an assembly of the bacteriochloropyll a molecules into B850 and B875 groups of cyclic bacterial light-harvesting complexes LH2 and LH1, respectively, results an almost total loss of the intra-molecular vibronic structure in the fluorescence spectrum, and simultaneously, an essential enhancement of its phonon sideband due to electron-phonon coupling. While the suppression of the vibronic coupling in delocalized (excitonic) molecular systems is predictable, as also confirmed by our model calculations, a boost of the electron-phonon coupling is rather unexpected. The latter phenomenon is explained by exciton self-trapping, promoted by mixing the molecular exciton states with charge transfer states between the adjacent chromophores in the tightly packed B850 and B875 arrangements. Similar, although less dramatic trends were noted for the light-harvesting complexes containing chlorophyll pigments.

  9. Body Temperature Controlled Optical and Thermal Information Storage Light Scattering Display with Fluorescence Effect and High Mechanical Strength.

    Science.gov (United States)

    Chen, Si; Tong, Xiaoqian; He, Huiwen; Ma, Meng; Shi, Yanqin; Wang, Xu

    2017-04-05

    A kind of body temperature controlled optical and thermal information storage light scattering display based on super strong liquid crystalline physical gel with special "loofah-like gel network" was successfully prepared. Such liquid crystal (LC) gel was obtained by mixing a dendritic gelator (POSS-G1-BOC), an azobenzene compound (2Azo2), and a phosphor tethered liquid crystalline host (5CB), which could show its best contrast ratio at around human body temperature under UV light because of the phosphor's fluorescence effect. The gel also has quite strong mechanical strength, which could be used in wearable device field especially under sunlight, even under the forcing conditions as harsh as being centrifuged for 10 min at the speed of 2000 r/min. The whole production process of such a display is quite simple and could lead to displays at any size through noncontact writing. We believe it will have wide applications in the future.

  10. Thermally Activated Delayed Fluorescence Emitters for Deep Blue Organic Light Emitting Diodes: A Review of Recent Advances

    Directory of Open Access Journals (Sweden)

    Thanh-Tuân Bui

    2018-03-01

    Full Text Available Organic light-emitting diodes offer attractive perspectives for the next generation display and lighting technologies. The potential is huge and the list of potential applications is almost endless. So far, blue emitters still suffer from noticeably inferior electroluminescence performances in terms of efficiency, lifespan, color quality, and charge injection/transport when compared to that of the other colors. Emitting materials matching the NTSC standard blue of coordinates (0.14, 0.08 are extremely rare and still constitutes the focus of numerous academic and industrial researches. In this context, we review herein the recent developments on highly emissive deep-blue thermally activated delayed fluorescence emitters that constitute the third-generation electroluminescent materials.

  11. Preservation of protein fluorescence in embedded human dendritic cells for targeted 3D light and electron microscopy.

    Science.gov (United States)

    Höhn, K; Fuchs, J; Fröber, A; Kirmse, R; Glass, B; Anders-Össwein, M; Walther, P; Kräusslich, H-G; Dietrich, C

    2015-08-01

    In this study, we present a correlative microscopy workflow to combine detailed 3D fluorescence light microscopy data with ultrastructural information gained by 3D focused ion beam assisted scanning electron microscopy. The workflow is based on an optimized high pressure freezing/freeze substitution protocol that preserves good ultrastructural detail along with retaining the fluorescence signal in the resin embedded specimens. Consequently, cellular structures of interest can readily be identified and imaged by state of the art 3D confocal fluorescence microscopy and are precisely referenced with respect to an imprinted coordinate system on the surface of the resin block. This allows precise guidance of the focused ion beam assisted scanning electron microscopy and limits the volume to be imaged to the structure of interest. This, in turn, minimizes the total acquisition time necessary to conduct the time consuming ultrastructural scanning electron microscope imaging while eliminating the risk to miss parts of the target structure. We illustrate the value of this workflow for targeting virus compartments, which are formed in HIV-pulsed mature human dendritic cells. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  12. Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Qiong Wu

    2018-04-01

    Full Text Available In this study, a series of bipolar fluorescence emitters named 2DPAc-OXD, DPAc-OXD, 2PTZ-OXD and PTZ-OXD were designed and synthesized with excellent yields. The characterization of materials was investigated by using nuclear magnetic resonance (NMR (1H, 13C, mass spectrometry and thermogravimetric analysis (TGA. To investigate device efficiencies, two different OLED devices (Device 1, Device 2 were fabricated with two different host materials (Bepp2, DPEPO. The Device 2 with 2PTZ-OXD as fluorescent emitter exhibited excellent power and current efficiencies of 6.88 Lm/W and 10.10 cd/A, respectively. The external quantum efficiency of 2PTZ-OXD was around 3.99% for Device 2. The overall device properties of phenothiazine donor were better than acridine derivatives.

  13. Immobilized/P25/DSAT and Immobilized/Kronos/DSAT on Photocatalytic Degradation of Reactive Red 4 Under Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Azami M. S.

    2016-01-01

    Full Text Available In this work, photocatalytic degradation of Reactive Red 4 (RR4 using immobilized P25 and kronos were performed under fluorescent light sources. The photocatalysis activity for both catalysts was investigated under fluorescent lamp source which consist UV and Visible light. The effect of various parameters such as initial concentration, initial pH and strenght of immobilized plate were studied. The result showed that 90% of RR4 dye was degrade in 1 hr using immobilized/kronos/DSAT at 100 mg L-1 of RR4 dye while 81% degradation was achieved by immobilized/P25/DSAT at the same condition. The lowest pH showed the higher photocatalytic activity. Hence, the effect of dye concentration and pH on the photocatalysis study can be related with the behavior of environmental pollution. The low strength showed by immobilized/P25/DSAT where it remain 37 % as compared with strength of immobilized/kronos/DSAT (52 wt.%. For the future work, the polymer binder like Polyvinyl alcohol (PVA, Polyethylene glycol (PEG, and others polymers can be apply in immobilized study to overcome the strength problem.

  14. Quantification of Material Fluorescence and Light Scattering Cross Sections Using Ratiometric Bandwidth-Varied Polarized Resonance Synchronous Spectroscopy.

    Science.gov (United States)

    Xu, Joanna Xiuzhu; Hu, Juan; Zhang, Dongmao

    2018-05-25

    Presented herein is the ratiometric bandwidth-varied polarized resonance synchronous spectroscopy (BVPRS2) method for quantification of material optical activity spectra. These include the sample light absorption and scattering cross-section spectrum, the scattering depolarization spectrum, and the fluorescence emission cross-section and depolarization spectrum in the wavelength region where the sample both absorbs and emits. This ratiometric BVPRS2 spectroscopic method is a self-contained technique capable of quantitatively decoupling material fluorescence and light scattering signal contribution to its ratiometric BVPRS2 spectra through the linear curve-fitting of the ratiometric BVPRS2 signal as a function of the wavelength bandwidth used in the PRS2 measurements. Example applications of this new spectroscopic method are demonstrated with materials that can be approximated as pure scatterers, simultaneous photon absorbers/emitters, simultaneous photon absorbers/scatterers, and finally simultaneous photon absorbers/scatterers/emitters. Because the only instruments needed for this ratiometric BVPRS2 technique are the conventional UV-vis spectrophotometer and spectrofluorometer, this work should open doors for routine decomposition of material UV-vis extinction spectrum into its absorption and scattering component spectra. The methodology and insights provided in this work should be of broad significance to all chemical research that involves photon/matter interactions.

  15. Correlative Light-Electron Microscopy of Lipid-Encapsulated Fluorescent Nanodiamonds for Nanometric Localization of Cell Surface Antigens.

    Science.gov (United States)

    Hsieh, Feng-Jen; Chen, Yen-Wei; Huang, Yao-Kuan; Lee, Hsien-Ming; Lin, Chun-Hung; Chang, Huan-Cheng

    2018-02-06

    Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ∼50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens.

  16. Improving the competency of dental hygiene students in detecting dental restorations using quantitative light-induced fluorescence technology.

    Science.gov (United States)

    Oh, Hye-Young; Jung, Hoi-In; Lee, Jeong-Woo; de Jong, Elbert de Josselin; Kim, Baek-Il

    2017-03-01

    The purpose of this study was to determine the usefulness of a quantitative light-induced fluorescence (QLF) technology in detecting dental restorations by comparing the detection ability of dental hygiene students between using conventional visual inspection alone and visual inspection combined with QLF technology. The subjects of this study comprised 92 dental hygiene students. The students assigned to the control group only used white-light images to visually assess the mouth environment, while those in the experimental group additionally used fluorescence images. Using the test results of an experienced inspector as a reference value, the agreement between the reference value and the evaluation results of the students in the experimental and control groups was evaluated using Cohen's kappa and the percentage agreement. The subjects were then classified into groups covering three percentage ranges according to the score distribution and agreement values of the three groups were compared. The percentage agreement was calculated according to the type of dental restorations. The mean kappa value was significantly higher in the experimental group than the control group (0.70 vs 0.60, ptechnology increased by 8% more in the middle and bottom percentage groups than in the top percentage group (ptechnology with conventional visual inspections could improve the ability to detect dental restorations and distinguish sound teeth from aesthetic restorations. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Oligonucleotide assisted light-emitting Alq3 microrods: energy transfer effect with fluorescent dyes.

    Science.gov (United States)

    Cui, Chunzhi; Park, Dong Hyuk; Kim, Jeongyong; Joo, Jinsoo; Ahn, Dong June

    2013-06-14

    Oligonucleotide assisted tri(8-hydroxyquinoline) aluminium (Alq3) microrods were prepared for the first time. When hybridized with oligonucleotide labeled by Cy3 fluorescent dye, a significant photoluminescence variation of the Alq3 microrods was observed due to Förster resonance energy transfer, unlike when Cy5-oligonucleotide was used. Versatile nucleotide manipulation would open up wider applications of Alq3-based materials, based on this fundamental observation.

  18. Purely organic thermally activated delayed fluorescence (TADF) materials for organic light-emitting diodes (OLEDs)

    OpenAIRE

    Wong, Michael Y.; Zysman-Colman, Eli

    2017-01-01

    We thank the University of St Andrews for support. EZ-C thanks the Leverhulme Trust for financial support (RPG-2016-047). and the EPSRC (EP/P010482/1) for financial support. The design of thermally activated delayed fluorescence (TADF) materials both as emitters and as hosts is an exploding area of research. The replacement of phosphorescent metal complexes with inexpensive organic compounds in electroluminescent (EL) devices that demonstrate comparable performance metrics is paradigm shif...

  19. Analysis of plastid number, size, and distribution in Arabidopsis plants by light and fluorescence microscopy.

    Science.gov (United States)

    Pyke, Kevin

    2011-01-01

    Methods are described which allow one to observe chloroplasts in mesophyll cells from leaves of Arabidopsis, determine their number per cell, measure their area, and determine a value for chloroplast coverage inside mesophyll cells. Non-green plastids can also be imaged either by using staining, or by exploiting fluorescent proteins targeted to the plastid in non-green parts of the plant, such as the roots, in transgenic Arabidopsis.

  20. Light emitting diode, photodiode-based fluorescence detection system for DNA analysis with microchip electrophoresis.

    Science.gov (United States)

    Hall, Gordon H; Glerum, D Moira; Backhouse, Christopher J

    2016-02-01

    Electrophoretic separation of fluorescently end-labeled DNA after a PCR serves as a gold standard in genetic diagnostics. Because of their size and cost, instruments for this type of analysis have had limited market uptake, particularly for point-of-care applications. This might be changed through a higher level of system integration and lower instrument costs that can be realized through the use of LEDs for excitation and photodiodes for detection--if they provide sufficient sensitivity. Here, we demonstrate an optimized microchip electrophoresis instrument using polymeric fluidic chips with fluorescence detection of end-labeled DNA with a LOD of 0.15 nM of Alexa Fluor 532. This represents orders of magnitude improvement over previously reported instruments of this type. We demonstrate the system with an electrophoretic separation of two PCR products and their respective primers. We believe that this is the first LED-induced fluorescence microchip electrophoresis system with photodiode-based detection that could be used for standard applications of PCR and electrophoresis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Introduction of Red-Green-Blue Fluorescent Dyes into a Metal-Organic Framework for Tunable White Light Emission.

    Science.gov (United States)

    Wen, Yuehong; Sheng, Tianlu; Zhu, Xiaoquan; Zhuo, Chao; Su, Shaodong; Li, Haoran; Hu, Shengmin; Zhu, Qi-Long; Wu, Xintao

    2017-10-01

    The unique features of the metal-organic frameworks (MOFs), including ultrahigh porosities and surface areas, tunable pores, endow the MOFs with special utilizations as host matrices. In this work, various neutral and ionic guest dye molecules, such as fluorescent brighteners, coumarin derivatives, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM), and 4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM), are encapsulated in a neutral MOF, yielding novel blue-, green-, and red-phosphors, respectively. Furthermore, this study introduces the red-, green-, and blue-emitting dyes into a MOF together for the first time, producing white-light materials with nearly ideal Commission International ed'Eclairage (CIE) coordinates, high color-rendering index values (up to 92%) and quantum yields (up to 26%), and moderate correlated color temperature values. The white light is tunable by changing the content or type of the three dye guests, or the excitation wavelength. Significantly, the introduction of blue-emitting guests in the methodology makes the available MOF host more extensive, and the final white-light output more tunable and high-quality. Such strategy can be widely adopted to design and prepare white-light-emitting materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Controlled light emission from white organic light-emitting devices with a single blue-emitting host and multiple fluorescent dopants

    International Nuclear Information System (INIS)

    Chin, Byung Doo; Kim, Jai Kyeong; Park, O Ok

    2007-01-01

    In this work, we fabricated white organic light-emitting devices (WOLEDs) containing a layered light-emitting region composed of a single blue-emitting host and different fluorescent dopant materials. The effects of varying the dye-doping ratio and emitting layer thickness on the efficiency, lifetime, spectral voltage-dependence and white balance were investigated for devices with a blue/orange stacked layer structure. Addition of a blue host layer doped with a green-emitting dopant, to give a blue/green/orange emitter, resulted in a broadband white spectrum without the need for a charge-blocking interlayer. The composition of blue, green and orange dopants in the host and the thickness of each emitting layer were optimized, resulting in a device efficiency of 9-11 cd A -1 even at a high brightness of 10 000 cd m -2 (achieved at a bias voltage of less than 9 V) with an emission spectrum suitable for lighting applications

  3. Photosynthesis, chlorophyll fluorescence, light-harvesting system and photoinhibition resistance of a zeaxanthin-accumulating mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Tardy, F; Havaux, M

    1996-06-01

    The abscisic-acid-deficient aba-1 mutant of Arabidopsis thaliana is unable to epoxidize zeaxanthin. As a consequence, it contains large amounts of this carotenoid and lacks epoxy-xanthophylls. HPLC analysis of pigment contents in leaves, isolated thylakoids and preparations of the major light-harvesting complex of photosystem II (PSII) (LHC-II) indicated that zeaxanthin replaced neoxanthin, violaxanthin and antheraxanthin in the light-harvesting system of PSII in aba-1. Non-denaturing electrophoretic fractionation of solubilized thylakoids showed that the xanthophyll imbalance in aba-1 was associated with a pronounced decrease in trimeric LHC-II in favour of monomeric complexes, with a substantial increase in free pigments (mainly zeaxanthin and chlorophyll b), suggesting a decreased stability of LHC-II. The reduced thermostability of PSII in aba-1 was also deduced from in vivo chlorophyll fluorescence measurements. Wild-type and aba-1 leaves could not be distinguished on the basis of their photosynthetic performance: no significant difference was observed between the two types of leaves for light-limited and light-saturated photosynthetic oxygen evolution, PSII photochemistry and PSII to PSI electron flow. When dark-adapted leaves (grown in white light of 80 mumol m-2s-1) were suddenly exposed to red light of 150 mumol m-2s-1, there was a strong nonphotochemical quenching of chlorophyll fluorescence, the amplitude of which was virtually identical (at steady state) in aba-1 and wild-type leaves, despite the fact that the xanthophyll cycle pigment pool was completely in the form of zeaxanthin in aba-1 and almost exclusively in the form of violaxanthin in the wild type. A high concentration of zeaxanthin in aba-1 thylakoids did not, in itself, provide any particular protection against the photoinhibition of PSII. Taken together, the presented results indicate the following: (1) zeaxanthin can replace epoxy-xanthophylls in LHC-II without significantly affecting the

  4. Intraocular light scatter, reflections, fluorescence and absorption: what we see in the slit lamp.

    Science.gov (United States)

    van den Berg, Thomas J T P

    2018-01-01

    Much knowledge has been collected over the past 20 years about light scattering in the eye- in particular in the eye lens- and its visual effect, called straylight. It is the purpose of this review to discuss how these insights can be applied to understanding the slit lamp image. The slit lamp image mainly results from back scattering, whereas the effects on vision result mainly from forward scatter. Forward scatter originates from particles of about wavelength size distributed throughout the lens. Most of the slit lamp image originates from small particle scatter (Rayleigh scatter). For a population of middle aged lenses it will be shown that both these scatter components remove around 10% of the light from the direct beam. For slit lamp observation close to the reflection angles, zones of discontinuity (Wasserspalten) at anterior and posterior parts of the lens show up as rough surface reflections. All these light scatter effects increase with age, but the correlations with age, and also between the different components, are weak. For retro-illumination imaging it will be argued that the density or opacity seen in areas of cortical or posterior subcapsular cataract show up because of light scattering, not because of light loss. NOTES: (1) Light scatter must not be confused with aberrations. Light penetrating the eye is divided into two parts: a relatively small part is scattered, and removed from the direct beam. Most of the light is not scattered, but continues as the direct beam. This non-scattered part is the basis for functional imaging, but its quality is under the control of aberrations. Aberrations deflect light mainly over small angles (light scatter is important because of the straylight effects over large angles (>1°), causing problems like glare and hazy vision. (2) The slit lamp image in older lenses and nuclear cataract is strongly influenced by absorption. However, this effect is greatly exaggerated by the light path lengths concerned. This

  5. Daytime Cognitive Performance in Response to Sunlight or Fluorescent Light Controlling for Sleep Duration

    Science.gov (United States)

    Ramos, Jhanic; Zamos, Adela; Rao, Rohit; Flynn-Evans, Erin

    2015-01-01

    Light is the primary synchronizer of the human circadian rhythm and also has acute alerting effects. Our study involves and comparing the alertness, performance and sleep of participants in the NASA Ames Sustainability Base, which uses sunlight as its primary light source, to in a traditional office building which uses overhead florescent lighting and varying exposure to natural light. The purpose of this study is to determine whether the use of natural lighting as a primary light source improves daytime cognitive function and promotes nighttime sleep. Participants from the Sustainability Base will be matched by gender and age to individuals working in other NASA buildings. In a prior study we found no differences in performance between those working in the Sustainability Base and those working in other buildings. Unexpectedly, we found that the average sleep duration among participants in both buildings was short, which likely obscured our ability to detect a difference the effect of light exposure on alertness. Given that such sleep deprivation has negative effects on cognitive performance, in this iteration of the study we are asking the participants to maintain a regular schedule with eight hours in bed each night in order to control for the effect of self-selected sleep restriction. Over the course of one week, we will ask the participants to wear actiwatches continuously, complete a psychomotor vigilance task (PVT) and digit symbol substitution task (DSST) three times per day, and keep daily sleepwork diaries. We hope that this study will provide data to support the idea that natural lighting and green architectural design are optimal to enhance healthy nighttime sleep patterns and daytime cognitive performance.

  6. X-ray fluorescence diffractionless analyzer for determining light element content in iron ore mixtures

    International Nuclear Information System (INIS)

    Yuksa, L.K.; Kochmola, N.M.; Bondarenko, V.P.; Bogdanov, V.K.

    1986-01-01

    Diffractionless X-ray fluorescence analyzer for detecting calcium oxide and silicon dioxide contents in dry iron ore materials has been developed. The analyzer includes a charging unit, sample-conveying device, spectrometric units for detecting calcium and silicon, computing racks and sample-removing device. Results of calcium oxide and silicon dioxide analyses in iron ore mixtures are presented. Errors are evaluated. It is shown that the analyzer provides high accuracy of one-time determinations, as well as reading constancy for a long time

  7. In-vacuum scattered light reduction with black cupric oxide surfaces for sensitive fluorescence detection.

    Science.gov (United States)

    Norrgard, E B; Sitaraman, N; Barry, J F; McCarron, D J; Steinecker, M H; DeMille, D

    2016-05-01

    We demonstrate a simple and easy method for producing low-reflectivity surfaces that are ultra-high vacuum compatible, may be baked to high temperatures, and are easily applied even on complex surface geometries. Black cupric oxide (CuO) surfaces are chemically grown in minutes on any copper surface, allowing for low-cost, rapid prototyping, and production. The reflective properties are measured to be comparable to commercially available products for creating optically black surfaces. We describe a vacuum apparatus which uses multiple blackened copper surfaces for sensitive, low-background detection of molecules using laser-induced fluorescence.

  8. Old traces, read anew - 'The Reading Hermit' painting in the light of X-ray fluorescence

    OpenAIRE

    Seim, C.; Laurenze-Landsberg, C.; Schröder-Smeibidl, B.; Mantouvalou, I.; Boer, C. de; Kanngießer, B.

    2014-01-01

    There exist several very similar looking versions of the painting ‘The Reading Hermit’, all allegedly painted by Rembrandt Harmenszoon van Rijn (approx. in ∼1630 A.D., Leiden). The classification of Rembrandt's paintings, which were produced by Rembrandt himself, in his academy by his students and the ones being mere copies is a crucial and difficult task. We gathered background evidence and performed elemental analyses by non-destructive micro-X-ray fluorescence (micro-XRF) in order to eluci...

  9. The influence of visible light and inorganic pigments on fluorescence excitation emission spectra of egg-, casein- and collagen-based painting media

    Science.gov (United States)

    Nevin, A.; Anglos, D.; Cather, S.; Burnstock, A.

    2008-07-01

    Spectrofluorimetric analysis of proteinaceous binding media is particularly promising because proteins employed in paintings are often fluorescent and media from different sources have significantly different fluorescence spectral profiles. Protein-based binding media derived from eggs, milk and animal tissue have been used for painting and for conservation, but their analysis using non-destructive techniques is complicated by interferences with pigments, their degradation and their low concentration. Changes in the fluorescence excitation emission spectra of films of binding media following artificial ageing to an equivalent of 50 and 100 years of museum lighting include the reduction of bands ascribed to tyrosine, tryptophan and Maillard reaction products and an increase in fluorescent photodegradation. Fluorescence of naturally aged paint is dependent on the nature of the pigment present and, with egg-based media, in comparison with un-pigmented films, emissions ascribed to amino acids are more pronounced.

  10. Fluorescence measurements show stronger cold inhibition of photosynthetic light reactions in Scots pine compared to Norway spruce as well as during spring compared to autumn.

    Science.gov (United States)

    Linkosalo, Tapio; Heikkinen, Juha; Pulkkinen, Pertti; Mäkipää, Raisa

    2014-01-01

    We studied the photosynthetic activity of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst) in relation to air temperature changes from March 2013 to February 2014. We measured the chlorophyll fluorescence of approximately 50 trees of each species growing in southern Finland. Fluorescence was measured 1-3 times per week. We began by measuring shoots present in late winter (i.e., March 2013) before including new shoots once they started to elongate in spring. By July, when the spring shoots had achieved similar fluorescence levels to the older ones, we proceeded to measure the new shoots only. We analyzed the data by fitting a sigmoidal model containing four parameters to link sliding averages of temperature and fluorescence. A parameter defining the temperature range over which predicted fluorescence increased most rapidly was the most informative with in describing temperature dependence of fluorescence. The model generated similar fluorescence patterns for both species, but differences were observed for critical temperature and needle age. Down regulation of the light reaction was stronger in spring than in autumn. Pine showed more conservative control of the photosynthetic light reactions, which were activated later in spring and more readily attenuated in autumn. Under the assumption of a close correlation of fluorescence and photosynthesis, spruce should therefore benefit more than pine from the increased photosynthetic potential during warmer springs, but be more likely to suffer frost damage with a sudden cooling following a warm period. The winter of 2013-2014 was unusually mild and similar to future conditions predicted by global climate models. During the mild winter, the activity of photosynthetic light reactions of both conifers, especially spruce, remained high. Because light levels during winter are too low for photosynthesis, this activity may translate to a net carbon loss due to respiration.

  11. Fluorescence measurements show stronger cold inhibition of photosynthetic light reactions in Scots pine compared to Norway spruce as well as during spring compared to autumn

    Directory of Open Access Journals (Sweden)

    Tapio eLinkosalo

    2014-06-01

    Full Text Available We studied the photosynthetic activity of Scots pine (Pinus sylvestris L. and Norway spruce (Picea abies [L.] Karst in relation to air temperature changes from March 2013 to February 2014. We measured the chlorophyll fluorescence of approximately 50 trees of each species growing in southern Finland. Fluorescence was measured 13 times per week. We began by measuring shoots present in late winter (i.e., March 2013 before including new shoots once they started to elongate in spring. By July, when the spring shoots had achieved similar fluorescence levels to the older ones, we proceeded to measure the new shoots only.We analysed the data by fitting a sigmoidal model containing four parameters to link sliding averages of temperature and fluorescence. A parameter defining the temperature range over which predicted fluorescence increased most rapidly was the most informative with in describing temperature dependence of fluorescence.The model generated similar fluorescence patterns for both species, but differences were observed for critical temperature and needle age. Down regulation of the light reaction was stronger in spring than in autumn. Pine showed more conservative control of the photosynthetic light reactions, which were activated later in spring and more readily attenuated in autumn. Under the assumption of a close correlation of fluorescence and photosynthesis, spruce should therefore benefit more than pine from the increased photosynthetic potential during warmer springs, but be more likely to suffer frost damage with a sudden cooling following a warm period. The winter of 20132014 was unusually mild and similar to future conditions predicted by global warming models. During the mild winter, the activity of photosynthetic light reactions of both conifers, especially spruce, remained high. Because light levels during winter are too low for photosynthesis, this activity may translate to a net carbon loss due to respiration.

  12. White light emission from fluorescent SiC with porous surface

    DEFF Research Database (Denmark)

    Lu, Weifang; Ou, Yiyu; Fiordaliso, Elisabetta Maria

    2017-01-01

    We report for the frst time a NUV light to white light conversion in a N-B co-doped 6H-SiC (fuorescent SiC) layer containing a hybrid structure. The surface of fuorescent SiC sample contains porous structures fabricated by anodic oxidation method. After passivation by 20nm thick Al2O3, the photol......We report for the frst time a NUV light to white light conversion in a N-B co-doped 6H-SiC (fuorescent SiC) layer containing a hybrid structure. The surface of fuorescent SiC sample contains porous structures fabricated by anodic oxidation method. After passivation by 20nm thick Al2O3...... the bulk fuorescent SiC layer. A high color rendering index of 81.1 has been achieved. Photoluminescence spectra in porous layers fabricated in both commercial n-type and lab grown N-B co-doped 6H-SiC show two emission peaks centered approximately at 460nm and 530nm. Such bluegreen emission phenomenon can......, the photoluminescence intensity from the porous layer was signifcant enhanced by a factor of more than 12. Using a porous layer of moderate thickness (~10µm), high-quality white light emission was realized by combining the independent emissions of blue-green emission from the porous layer and yellow emission from...

  13. New light on ion channel imaging by total internal reflection fluorescence (TIRF) microscopy.

    Science.gov (United States)

    Yamamura, Hisao; Suzuki, Yoshiaki; Imaizumi, Yuji

    2015-05-01

    Ion channels play pivotal roles in a wide variety of cellular functions; therefore, their physiological characteristics, pharmacological responses, and molecular structures have been extensively investigated. However, the mobility of an ion channel itself in the cell membrane has not been examined in as much detail. A total internal reflection fluorescence (TIRF) microscope allows fluorophores to be imaged in a restricted region within an evanescent field of less than 200 nm from the interface of the coverslip and plasma membrane in living cells. Thus the TIRF microscope is useful for selectively visualizing the plasmalemmal surface and subplasmalemmal zone. In this review, we focused on a single-molecule analysis of the dynamic movement of ion channels in the plasma membrane using TIRF microscopy. We also described two single-molecule imaging techniques under TIRF microscopy: fluorescence resonance energy transfer (FRET) for the identification of molecules that interact with ion channels, and subunit counting for the determination of subunit stoichiometry in a functional channel. TIRF imaging can also be used to analyze spatiotemporal Ca(2+) events in the subplasmalemma. Single-molecule analyses of ion channels and localized Ca(2+) signals based on TIRF imaging provide beneficial pharmacological and physiological information concerning the functions of ion channels. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  14. Pulsed lasers versus continuous light sources in capillary electrophoresis and fluorescence detection studies: Photodegradation pathways and models

    International Nuclear Information System (INIS)

    Boutonnet, Audrey; Morin, Arnaud; Petit, Pierre; Vicendo, Patricia; Poinsot, Véréna; Couderc, François

    2016-01-01

    Pulsed lasers are widely used in capillary electrophoresis (CE) studies to provide laser induced fluorescence (LIF) detection. Unfortunately pulsed lasers do not give linear calibration curves over a wide range of concentrations. While this does not prevent their use in CE/LIF studies, the non-linear behavior must be understood. Using 7-hydroxycoumarin (7-HC) (10–5000 nM), Tamra (10–5000 nM) and tryptophan (1–200 μM) as dyes, we observe that continuous lasers and LEDs result in linear calibration curves, while pulsed lasers give polynomial ones. The effect is seen with both visible light (530 nm) and with UV light (355 nm, 266 nm). In this work we point out the formation of byproducts induced by pulsed laser upon irradiation of 7-HC. Their separation by CE using two Zeta LIF detectors clearly shows that this process is related to the first laser detection. All of these photodegradation products can be identified by an ESI-/MS investigation and correspond to at least two 7HC dimers. By using the photodegradation model proposed by Heywood and Farnsworth (2010) and by taking into account the 7-HC results and the fact that in our system we do not have a constant concentration of fluorophore, it is possible to propose a new photochemical model of fluorescence in LIF detection. The model, like the experiment, shows that it is difficult to obtain linear quantitation curves with pulsed lasers while UV-LEDs used in continuous mode have this advantage. They are a good alternative to UV pulsed lasers. An application involving the separation and linear quantification of oligosaccharides labeled with 2-aminobezoic acid is presented using HILIC and LED (365 nm) induced fluorescence. - Highlights: • No linear calibration curves are obtained in CE/Pulsed-LIF detection. • Photodegradation and photodimerisation are responsible of this non linearity. • A mathematical model of this phenomenon is presented. • 7 hydroxycoumarin in CE/LIF is used to verify the

  15. An assessment of the importance ofexposure routes to the uptake and internal localisation of fluorescent nanoparticles in zebrafish (Danio rerio), using light sheet microscopy

    DEFF Research Database (Denmark)

    Skjolding, Lars Michael; Ašmonaitė, G; Jølck, Rasmus Irming

    2017-01-01

    A major challenge in nanoecotoxicology is finding suitable methods to determine the uptake and localisation of nanoparticles on a whole-organism level. Some uptake methods have been associated with artefacts induced by sample preparation, including staining for electron microscopy. This study used...... light sheet microscopy (LSM) to define the uptake and localisation of fluorescently labelled nanoparticles in living organisms with minimal sample preparation. Zebrafish (Danio rerio) were exposed to fluorescent gold nanoparticles (Au NPs) and fluorescent polystyrene NPs via aqueous or dietary exposure...

  16. Fluorescent Silicon Carbide and its Applications in White Light-Emitting Diodes

    DEFF Research Database (Denmark)

    Ou, Yiyu

    light extraction efficiency are presented. White LEDs are the most promising techniques to replace the conventional lighting sources. A typical white LED consists of a Gallium Nitride (GaN) blue or Ultraviolet (UV) LED stack and a wavelengthconversion material. Silicon Carbide (SiC) has a wide optical...... rendering performance and a much longer material lifetime compared with the commonly used wavelength-conversion material like Phosphors. In this thesis, f-SiC with different doping concentrations are analyzed and optimized in order to enhance the quantum efficiency. On the other hand, semiconductor...

  17. Application of exciplex in the fabrication of white organic light emitting devices with mixed fluorescent and phosphorescent layers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dan; Duan, Yahui; Yang, Yongqiang [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012 (China); Hu, Nan [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012 (China); Changchun University of Science and Technology, Changchun 130012 (China); Wang, Xiao [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012 (China); Sun, Fengbo [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012 (China); Changchun University of Science and Technology, Changchun 130012 (China); Duan, Yu, E-mail: duanyu@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012 (China)

    2015-10-15

    In this study, a highly efficient fluorescent/phosphorescent white organic light-emitting device (WOLED) was fabricated using exciplex light emission. The hole-transport material 4,4',4''-tris(N-carbazolyl)triphenylamine (TCTA), and electron-transport material, 4,7-diphenyl-1,10-phenanthroline (Bphen), were mixed to afford a blue-emitting exciplex. The WOLED was fabricated with a yellow phosphorescent dye, Ir(III) bis(4-phenylthieno [3,2-c] pyridinato-N,C{sup 2'}) acetylacetonate (PO-01), combined with the exciplex. In this structure, the energy can be efficiently transferred from the blend layer to the yellow phosphorescent dye, thus improving the efficiency of the utilization of the triplet exciton. The maximum power efficiency of the WOLED reached a value 9.03 lm/W with an external quantum efficiency of 4.3%. The Commission Internationale de I'Eclairage (CIE) color coordinates (x,y) of the device were from (0.39, 0.45) to (0.27, 0.31), with a voltage range of 4–9 V. - Highlights: • An exciplex/phosphorescence hybrid white OLED was fabricated for the first time with blue/orange complementary emitters. • By using exciplex as the blue emitter, non-radiative triplet-states on the exciplex can be harvested for light-emission by transferring them to low triplet-state phosphors.

  18. Design and testing of a separate-type lighting system using solar energy and cold-cathode fluorescent lamps

    International Nuclear Information System (INIS)

    Yang, J.-P.; Hsiao, H.-C.

    2007-01-01

    This paper presents a solar-powered lighting system, using cold-cathode fluorescent-lamps (CCFLs), with its battery-charging circuit and lamp-ignition circuit being separated so that its solar panels can be installed at any distance deemed necessary away from the lighting site in order to receive the maximum solar energy available. This system adopts the maximum-power point tracking (MPPT) method to control the power output of the solar panels and uses the zero-voltage switching (ZVS) DC-DC converter, as the charging circuit, to increase the panels' power generation efficiency and the charging circuit's conversion efficiency. The electronic ballast circuit for the CCFL is constructed with a half-bridge inverter, a resonant inductor, and a Rosen-type piezoelectric transformer, which forms a piezoelectric resonant-type inverter: to simplify the circuitry and to improve the power conversion efficiency, the ballast circuit is designed to directly step up the battery voltage in igniting the lamp. We also establish the transmission-parameter model for the piezoelectric resonant-type inverter to provide the base for the electric-power circuit design. Our experimental results indicate that the proposed system possesses some advantages, such as greater energy efficiency, circuitry simplicity, and so on, and is suitable for night lighting in house yards, parks and advertising panels

  19. Design and testing of a separate-type lighting system using solar energy and cold-cathode fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.-P. [Department of Electrical Engineering, China Institute of Technology, Taipei, Taiwan 115, Taiwan (China)]. E-mail: april4120@tp.edu.tw; Hsiao, H.-C. [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 106, Taiwan (China)]. E-mail: hsiao@mouse.ee.ntust.edu.tw

    2007-01-15

    This paper presents a solar-powered lighting system, using cold-cathode fluorescent-lamps (CCFLs), with its battery-charging circuit and lamp-ignition circuit being separated so that its solar panels can be installed at any distance deemed necessary away from the lighting site in order to receive the maximum solar energy available. This system adopts the maximum-power point tracking (MPPT) method to control the power output of the solar panels and uses the zero-voltage switching (ZVS) DC-DC converter, as the charging circuit, to increase the panels' power generation efficiency and the charging circuit's conversion efficiency. The electronic ballast circuit for the CCFL is constructed with a half-bridge inverter, a resonant inductor, and a Rosen-type piezoelectric transformer, which forms a piezoelectric resonant-type inverter: to simplify the circuitry and to improve the power conversion efficiency, the ballast circuit is designed to directly step up the battery voltage in igniting the lamp. We also establish the transmission-parameter model for the piezoelectric resonant-type inverter to provide the base for the electric-power circuit design. Our experimental results indicate that the proposed system possesses some advantages, such as greater energy efficiency, circuitry simplicity, and so on, and is suitable for night lighting in house yards, parks and advertising panels.

  20. Application of exciplex in the fabrication of white organic light emitting devices with mixed fluorescent and phosphorescent layers

    International Nuclear Information System (INIS)

    Yang, Dan; Duan, Yahui; Yang, Yongqiang; Hu, Nan; Wang, Xiao; Sun, Fengbo; Duan, Yu

    2015-01-01

    In this study, a highly efficient fluorescent/phosphorescent white organic light-emitting device (WOLED) was fabricated using exciplex light emission. The hole-transport material 4,4',4''-tris(N-carbazolyl)triphenylamine (TCTA), and electron-transport material, 4,7-diphenyl-1,10-phenanthroline (Bphen), were mixed to afford a blue-emitting exciplex. The WOLED was fabricated with a yellow phosphorescent dye, Ir(III) bis(4-phenylthieno [3,2-c] pyridinato-N,C 2' ) acetylacetonate (PO-01), combined with the exciplex. In this structure, the energy can be efficiently transferred from the blend layer to the yellow phosphorescent dye, thus improving the efficiency of the utilization of the triplet exciton. The maximum power efficiency of the WOLED reached a value 9.03 lm/W with an external quantum efficiency of 4.3%. The Commission Internationale de I'Eclairage (CIE) color coordinates (x,y) of the device were from (0.39, 0.45) to (0.27, 0.31), with a voltage range of 4–9 V. - Highlights: • An exciplex/phosphorescence hybrid white OLED was fabricated for the first time with blue/orange complementary emitters. • By using exciplex as the blue emitter, non-radiative triplet-states on the exciplex can be harvested for light-emission by transferring them to low triplet-state phosphors

  1. Monitoring human neutrophil granule secretion by flow cytometry: secretion and membrane potential changes assessed by light scatter and a fluorescent probe of membrane potential

    International Nuclear Information System (INIS)

    Fletcher, M.P.; Seligmann, B.E.

    1985-01-01

    Purified human peripheral blood polymorphonuclear neutrophils (PMN) were incubated at 37 degrees C with the fluorescent membrane potential sensitive cyanine dye di-O-C(5)(3) and exposed to a number of stimulatory agents (N-formylmethionylleucylphenylalanine (FMLP), cytochalasin B (cyto B) + FMLP, phorbol myristate acetate (PMA). Flow cytometry was utilized to measure changes in forward light scatter (FS), orthogonal light scatter (90 degrees-SC), and fluorescence intensity of individual cells over time. A saturating (10(-6) M) dose of FMLP lead to a significant increase in the cells' FS without a change in 90 degrees-SC as well as a heterogeneous loss of di-O-C(5)(3) fluorescence. PMA (100 ng/ml) also caused an increase in FS but a uniform loss of dye fluorescence by all cells (apparent depolarization). Cyto B + FMLP produced an increase in FS, a marked loss of 90 degrees-SC, and a uniform loss of fluorescence. Secretion experiments under identical incubation conditions indicated a significantly positive relationship between loss of enzyme markers or cell granularity and orthogonal light scatter (r . 0.959, 0.998, and 0.989 for loss of 90 degrees-SC vs lysozyme, beta-glucuronidase, and granularity index, respectively). Flow cytometric light scatter measurements may yield important information on the extent of prior cell degranulation or activation

  2. Hybrid white organic light-emitting devices based on phosphorescent iridium-benzotriazole orange-red and fluorescent blue emitters

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Zhen-Yuan, E-mail: xiazhenyuan@hotmail.com [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Su, Jian-Hua [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Chang, Chi-Sheng; Chen, Chin H. [Display Institute, Microelectronics and Information Systems Research Center, National Chiao Tung University, Hsinchu, Taiwan 300 (China)

    2013-03-15

    We demonstrate that high color purity or efficiency hybrid white organic light-emitting devices (OLEDs) can be generated by integrating a phosphorescent orange-red emitter, bis[4-(2H-benzotriazol-2-yl)-N,N-diphenyl-aniline-N{sup 1},C{sup 3}] iridium acetylacetonate, Ir(TBT){sub 2}(acac) with fluorescent blue emitters in two different emissive layers. The device based on deep blue fluorescent material diphenyl-[4-(2-[1,1 Prime ;4 Prime ,1 Double-Prime ]terphenyl-4-yl-vinyl)-phenyl]-amine BpSAB and Ir(TBT){sub 2}(acac) shows pure white color with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33,0.30). When using sky-blue fluorescent dopant N,N Prime -(4,4 Prime -(1E,1 Prime E)-2,2 Prime -(1,4-phenylene)bis(ethene-2,1-diyl) bis(4,1-phenylene))bis(2-ethyl-6-methyl-N-phenylaniline) (BUBD-1) and orange-red phosphor with a color-tuning phosphorescent material fac-tris(2-phenylpyridine) iridium (Ir(ppy){sub 3} ), it exhibits peak luminance yield and power efficiency of 17.4 cd/A and 10.7 lm/W, respectively with yellow-white color and CIE color rendering index (CRI) value of 73. - Highlights: Black-Right-Pointing-Pointer An iridium-based orange-red phosphor Ir(TBT){sub 2}(acac) was applied in hybrid white OLEDs. Black-Right-Pointing-Pointer Duel- and tri-emitter WOLEDs were achieved with either high color purity or efficiency performance. Black-Right-Pointing-Pointer Peak luminance yield of tri-emitter WOLEDs was 17.4 cd/A with yellow-white color and color rendering index (CRI) value of 73.

  3. Hybrid white organic light-emitting devices based on phosphorescent iridium–benzotriazole orange–red and fluorescent blue emitters

    International Nuclear Information System (INIS)

    Xia, Zhen-Yuan; Su, Jian-Hua; Chang, Chi-Sheng; Chen, Chin H.

    2013-01-01

    We demonstrate that high color purity or efficiency hybrid white organic light-emitting devices (OLEDs) can be generated by integrating a phosphorescent orange–red emitter, bis[4-(2H-benzotriazol-2-yl)-N,N-diphenyl-aniline-N 1 ,C 3 ] iridium acetylacetonate, Ir(TBT) 2 (acac) with fluorescent blue emitters in two different emissive layers. The device based on deep blue fluorescent material diphenyl-[4-(2-[1,1′;4′,1″]terphenyl-4-yl-vinyl)-phenyl]-amine BpSAB and Ir(TBT) 2 (acac) shows pure white color with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33,0.30). When using sky-blue fluorescent dopant N,N′-(4,4′-(1E,1′E)-2,2′-(1,4-phenylene)bis(ethene-2,1-diyl) bis(4,1-phenylene))bis(2-ethyl-6-methyl-N-phenylaniline) (BUBD-1) and orange–red phosphor with a color-tuning phosphorescent material fac-tris(2-phenylpyridine) iridium (Ir(ppy) 3 ), it exhibits peak luminance yield and power efficiency of 17.4 cd/A and 10.7 lm/W, respectively with yellow-white color and CIE color rendering index (CRI) value of 73. - Highlights: ► An iridium-based orange–red phosphor Ir(TBT) 2 (acac) was applied in hybrid white OLEDs. ► Duel- and tri-emitter WOLEDs were achieved with either high color purity or efficiency performance. ► Peak luminance yield of tri-emitter WOLEDs was 17.4 cd/A with yellow-white color and color rendering index (CRI) value of 73.

  4. Classification of quantitative light-induced fluorescence images using convolutional neural network

    NARCIS (Netherlands)

    Imangaliyev, S.; van der Veen, M.H.; Volgenant, C.M.C.; Loos, B.G.; Keijser, B.J.F.; Crielaard, W.; Levin, E.; Lintas, A.; Rovetta, S.; Verschure, P.F.M.J.; Villa, A.E.P.

    2017-01-01

    Images are an important data source for diagnosis of oral diseases. The manual classification of images may lead to suboptimal treatment procedures due to subjective errors. In this paper an image classification algorithm based on Deep Learning framework is applied to Quantitative Light-induced

  5. Modulation of fluorescence signals from biomolecules along nanowires due to interaction of light with oriented nanostructures

    DEFF Research Database (Denmark)

    Frederiksen, Rune Schøneberg; Alarcon-Llado, Esther; Madsen, Morten H.

    2015-01-01

    High aspect ratio nanostructures have gained increasing interest as highly sensitive platforms for biosensing. Here, well-defined biofunctionalized vertical indium arsenide nanowires are used to map the interaction of light with nanowires depending on their orientation and the excitation waveleng...

  6. Fluorescent lighting system of modified fast starting system; Sistema de alumbrado fluorescente de arranque rapido modificado

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza E, Ernesto J [Manufacturera De Reactores, S. A., Mexico, D. F. (Mexico)

    1994-12-31

    This paper puts into perspective the possible energy saving in using hybrid ballasts for the operation of fast starting lamps. It presents in summarized form some fundamentals of the fluorescent lamps operation, as well as the fast starting modified systems. Also the results of field operation are shown, as well as the effects on the useful life of the lamp T12 as well as the T8. [Espanol] Este trabajo pone en perspectiva el ahorro de energia posible, al emplear balastros hibridos para operar lamparas de arranque rapido. Presenta en forma resumida algunos fundamentos de la operacion de lamparas fluorescentes, asi como de los sistemas de arranque rapido modificado. Se muestran tambien resultados de operacion de campo, asi como los efectos sobre la vida util de las lamparas, tanto T12 como T8.

  7. Enhanced visualization of the bile duct via parallel white light and indocyanine green fluorescence laparoscopic imaging

    Science.gov (United States)

    Demos, Stavros G.; Urayama, Shiro

    2014-03-01

    Despite best efforts, bile duct injury during laparoscopic cholecystectomy is a major potential complication. Precise detection method of extrahepatic bile duct during laparoscopic procedures would minimize the risk of injury. Towards this goal, we have developed a compact imaging instrumentation designed to enable simultaneous acquisition of conventional white color and NIR fluorescence endoscopic/laparoscopic imaging using ICG as contrast agent. The capabilities of this system, which offers optimized sensitivity and functionality, are demonstrated for the detection of the bile duct in an animal model. This design could also provide a low-cost real-time surgical navigation capability to enhance the efficacy of a variety of other image-guided minimally invasive procedures.

  8. Fluorescent lighting system of modified fast starting system; Sistema de alumbrado fluorescente de arranque rapido modificado

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza E, Ernesto J. [Manufacturera De Reactores, S. A., Mexico, D. F. (Mexico)

    1993-12-31

    This paper puts into perspective the possible energy saving in using hybrid ballasts for the operation of fast starting lamps. It presents in summarized form some fundamentals of the fluorescent lamps operation, as well as the fast starting modified systems. Also the results of field operation are shown, as well as the effects on the useful life of the lamp T12 as well as the T8. [Espanol] Este trabajo pone en perspectiva el ahorro de energia posible, al emplear balastros hibridos para operar lamparas de arranque rapido. Presenta en forma resumida algunos fundamentos de la operacion de lamparas fluorescentes, asi como de los sistemas de arranque rapido modificado. Se muestran tambien resultados de operacion de campo, asi como los efectos sobre la vida util de las lamparas, tanto T12 como T8.

  9. A light-up fluorescent probe for citrate detection based on bispyridinum amides with aggregation-induced emission feature.

    Science.gov (United States)

    Liu, Chenchen; Hang, Yandi; Jiang, Tao; Yang, Ji; Zhang, Xiao; Hua, Jianli

    2018-02-01

    Citrate is an important intermediate in the citric acid cycle, a vital metabolic pathway for animals, plants and bacteria. It is of great significance to detect its levels in human beings because several diseases may cause the abnormal of citrate. In this paper, a new turn-on fluorescent sensor (TPE-Py) using the classic tetraphenylethylene (TPE) as the aggregation-induced emission (AIE) fluorophore and bipyridinium-based amides as the recognition receptor has been synthesized for the detection of citrate. The probe exhibits good selectivity and sensitivity to citrate with a relatively low detection limit (1.0 × 10 -7 M). The enhancement of the fluorescence is relevant with the AIE property based on the complexation of TPE-Py with citrate caused by the hydrogen bonding and electrostatic interactions between the bipyridinium diamides and citrate, which has been proved by 1 H NMR and mass spectra titration, scanning electronic microscope and dynamic light scattering analyses. More importantly, the quantification of citrate in artificial urine may develop TPE-Py fluorometric probe for the citrate detection in real biosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Red organic light emitting devices with reduced efficiency roll-off behavior by using hybrid fluorescent/phosphorescent emission structure

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Tianhang; Choy, Wallace C.H., E-mail: chchoy@eee.hku.h

    2010-11-01

    Organic light emitting device (OLED) with a fluorescence-interlayer-phosphorescence emissive structure (FIP EML) is proposed to solve efficiency roll-off issue effectively. By doping fluorescent emitter of 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) -4H-pyran (DCJTB) and phosphorescent emitter of tris(1-phenylisoquinolinolato-C2,N)iridium(III) (Ir(piq){sub 3}) into the different regions of emission zone to form FIP EML in red OLED, an improvement of more than 20% in luminance efficiency roll-off compared with that of typical phosphorescent OLED with single EML in 10-500 mA/cm{sup 2} range has been obtained. Detailed mechanisms have been studied. Such improvement should be attributed to the distinct roles of the two emitters, where DCJTB mainly used to influence the carrier transport leading to an improved balance of charge carriers while Ir(piq){sub 3} functions as the radiative decay sites for most generated excitons. Meanwhile, with the help of the formation of FIP EML, the redistribution of excitons in recombination zone, the suppression of non-radiative exciton quenching processes and the elimination of energy transfer loss also contribute to the enhancement of efficiency roll-off. The method proposed here may provide a route to develop efficient OLED for high luminance applications.

  11. An in vitro comparison of quantitative light-induced fluorescence-digital and spectrophotometer on monitoring artificial white spot lesions.

    Science.gov (United States)

    Kim, Hee Eun; Kim, Baek-Il

    2015-09-01

    The aim of this study was to evaluate the efficacy of quantitative light-induced fluorescence-digital (QLF-D) compared to a spectrophotometer in monitoring progression of enamel lesions. To generate artificial caries with various severities of lesion depths, twenty bovine specimens were immersed in demineralizing solution for 40 days. During the production of the lesions, repeat measurements of fluorescence loss (ΔF) and color change (ΔE) were performed in six distinct stages after the demineralization of the specimens: after 3, 5, 10, 20, 30, and 40 days of exposure to the demineralizing solution. Changes in the ΔF values in the lesions were analyzed using the QLF-D, and changes in the ΔE values in lesions were analyzed using a spectrophotometer. The repeated measures ANOVA of ΔF and ΔE values were used to determine whether there are significant differences at different exposure times in the demineralizing solution. Spearman's rank correlation coefficient was analyzed between ΔF and ΔE. The ΔF values significantly decreased based on the demineralizing period (pmonitoring color changes. Our findings demonstrate that QLF-D are a more efficient and stable tool for early caries detection. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Uptake and localization of fluorescent labelled gold nanoparticles in living zebrafish (Danio rerio) using Light Sheet Microscopy

    DEFF Research Database (Denmark)

    Skjolding, Lars Michael; Asmonaite, G.; Jolk, R.

    2015-01-01

    Despite nanoparticles being used in many different products and applications, the effects and fate in the environment are still not well understood. Uptake of nanoparticles into cells has been shown in vitro and in vivo. However, it is challenging to find suitable methods to identify uptake...... and determine localization on a whole organism level. Furthermore, methods used to identify nanoparticle uptake have been associated with artefacts induced by sample preparation including staining methods for electron microscopy.  This study used Fluorescent Light Sheet Microscopy (FLSM) to determine uptake...... to the particles through the diet or the water phase in a series of separate experiments. In the dietary exposure experiments Artemia salina were exposed to 1 mg Au/L for 24h before being fed to D. rerio. For exposure through the water phase 1 mg Au/L was added directly to aquaria holding the fish and non...

  13. Fluorescent optical position sensor

    Science.gov (United States)

    Weiss, Jonathan D.

    2005-11-15

    A fluorescent optical position sensor and method of operation. A small excitation source side-pumps a localized region of fluorescence at an unknown position along a fluorescent waveguide. As the fluorescent light travels down the waveguide, the intensity of fluorescent light decreases due to absorption. By measuring with one (or two) photodetectors the attenuated intensity of fluorescent light emitted from one (or both) ends of the waveguide, the position of the excitation source relative to the waveguide can be determined by comparing the measured light intensity to a calibrated response curve or mathematical model. Alternatively, excitation light can be pumped into an end of the waveguide, which generates an exponentially-decaying continuous source of fluorescent light along the length of the waveguide. The position of a photodetector oriented to view the side of the waveguide can be uniquely determined by measuring the intensity of the fluorescent light emitted radially at that location.

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

    Science.gov (United States)

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

    2016-12-13

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

  15. Detection of thermocouple malfunction in the Beacon system

    International Nuclear Information System (INIS)

    Morita, T.; Heibel, M.D.; Congedo, T.V.

    1992-01-01

    The BEACON system uses Core Exit Thermocouples (T/C) extensively for continuous radial power distribution monitoring. The T/C's are used to adjust the reference power distribution generated by the BEACON system to match the current radial power distribution. T/C reliability, repeatability, and relative accuracy have been very satisfactory. However, it is very important to detect any T/C malfunctions during operation, since a T/C signal change caused by an undetected malfunction can lead to serious errors in the radial power distribution developed by BEACON. A simple procedure has been developed which is capable of discriminating between changes in T/C signals caused by actual changes in reactor conditions and signal changes caused by T/C malfunctions

  16. An expert system for sensor data validation and malfunction detection

    International Nuclear Information System (INIS)

    Hashemi, S.; Hajek, B.K.; Miller, D.W.; Chandrasekaran, B.; Punch, W.F. III.

    1987-01-01

    During recent years, applications of expert systems in different fields of engineering have been under study throughout the world. At the Ohio State University, the theories developed by the Laboratory for Artificial Intelligence Research (LAIR) have been implemented for nuclear power plants and chemical processing systems. For nuclear power plants, these techniques have been further developed to reach diagnostic conclusions about malfunctions and faulty sensors, as well as to suggest corrective actions about the malfunctions. This paper concentrates on the AI applications to plant diagnosis and faulty sensor identifications. To achieve the above goals without adding extra sensors in a plant, the use of unlike sensor data (such as relationships between pressure and temperature in a Boiling Water Reactor (BWR)) and diagnostic conclusions about malfunctions as backups for suspicious sensors has been made. This extra evidence is readily available throughout the plant and is not generally used to backup suspicious sensor data in any manner

  17. The concept of explosives malfunctioning in rock blasting

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Q.

    1993-11-01

    The purpose is to identify the critical conditions that cause malfunctioning for some commonly used explosives. Experiments are described that measure sympathetic detonation, desensitization, and cut-offs for two variables: spacing and delay. Explosive malfunctioning is depicted on a delay spacing chart that has different regions. On the chart, the shape and size of each region can vary from one explosive to another. Results are presented from over 70 blasts, that were conducted in the underground drift at the CANMET Experimental Mine, to identify the malfunctioning characteristics of specific emulsion, water gel, and dynamite explosives. For each experiment, two parallel blastholes (with diameter of 32 mm and depth of 1.7 m) were drilled downwards, and full coupling was achieved. The results are presented for the three types of explosives tested. 11 refs., 7 figs.

  18. On the origin of the slow M-T chlorophyll a fluorescence decline in cyanobacteria: interplay of short-term light-responses.

    Science.gov (United States)

    Bernát, Gábor; Steinbach, Gábor; Kaňa, Radek; Govindjee; Misra, Amarendra N; Prašil, Ondřej

    2018-05-01

    The slow kinetic phases of the chlorophyll a fluorescence transient (induction) are valuable tools in studying dynamic regulation of light harvesting, light energy distribution between photosystems, and heat dissipation in photosynthetic organisms. However, the origin of these phases are not yet fully understood. This is especially true in the case of prokaryotic oxygenic photoautotrophs, the cyanobacteria. To understand the origin of the slowest (tens of minutes) kinetic phase, the M-T fluorescence decline, in the context of light acclimation of these globally important microorganisms, we have compared spectrally resolved fluorescence induction data from the wild type Synechocystis sp. PCC 6803 cells, using orange (λ = 593 nm) actinic light, with those of mutants, ΔapcD and ΔOCP, that are unable to perform either state transition or fluorescence quenching by orange carotenoid protein (OCP), respectively. Our results suggest a multiple origin of the M-T decline and reveal a complex interplay of various known regulatory processes in maintaining the redox homeostasis of a cyanobacterial cell. In addition, they lead us to suggest that a new type of regulatory process, operating on the timescale of minutes to hours, is involved in dissipating excess light energy in cyanobacteria.

  19. Fluorescence enhancement and nonreciprocal transmission of light waves by nanomaterial interfaces

    Science.gov (United States)

    Nyman, M.; Shevchenko, A.; Kaivola, M.

    2017-11-01

    In an optically absorbing or amplifying linear medium, the energy flow density of interfering optical waves is in general periodically modulated in space. This makes the wave transmission through a material boundary, as described by the Fresnel transmission coefficients, nonreciprocal and apparently violating the energy conservation law. The modulation has been previously described in connection to ordinary homogeneous nonmagnetic materials. In this work, we extend the description to nanomaterials with designed structural units that can be magnetic at optical frequencies. We find that in such a "metamaterial" the modulation in energy flow can be used to enhance optical far-field emission in spite of the fact that the material is highly absorbing. We also demonstrate a nanomaterial design that absorbs light, but simultaneously eliminates the power flow modulation and returns the reciprocity, which is impossible to achieve with a nonmagnetic material. We anticipate that these unusual optical effects can be used to increase the efficiency of nanostructured light emitters and absorbers, such as light-emitting diodes and solar cells.

  20. Fluorescent minerals - A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments

    Science.gov (United States)

    Omairi, Tareq; Wainwright, Milton

    2015-07-01

    We propose that green algae (Chlorella variabilis and Dunaliella tertiolecta) and cyanobacteria (Synechococcus elongatus and Nostoc commune) can grow inside fluorescent rock minerals which convert damaging UV light to visible light, thereby allowing these organisms to survive and thrive in UV-rich environments without (or with limited) visible light, which would otherwise be inimical to them. The four microorganisms were incubated inside fluorescent rocks composed of fluorite, calcite and pyrite. The resultant growth was then measured following exposure to UV radiation, with the use of optical density and measurement of chlorophyll concentration. Results show that the microorganisms were shielded from harmful UV in these semi-transparent rocks, while at the same time benefiting from the fact that the minerals converted UV to visible light; this have been shown by a statistically significant increase in their growth, which although lower than when the cells were incubated in sunlight, was significantly higher than in controls incubated in the dark.

  1. Breakthrough of ultraviolet light from various brands of fluorescent lamps: Lethal effects on DNA repair-defective bacteria

    International Nuclear Information System (INIS)

    Hartman, P.E.; Biggley, W.H.

    1996-01-01

    In a comparative study of 17 pairs of 15 W fluorescent lamps intended for use in homes and purchased in local stores, we detect over 10-fold differences in UVB + UVC emissions between various lamps. This breakthrough of ultraviolet (UV) light is in part correlated with ability of lamps to kill DNA repair-defective recA - uvrB - Salmonella. Relative proficiency of lamps in eliciting photoreactivation of UV-induced DNA lesions also plays a prominent role in the relative rates of bacterial inactivation by emissions from different lamps. Lamps made in Chile, such as Phillips brand lamps and one type of General Electric lamp, produce far less UVB + UVC and fail to kill recA - uvrB - bacteria. In contrast, all tested lamps manufactured in the USA, Hungary, and Japan exhibit readily observed deleterious biological effects. When an E. coli recA - uvrB - phr - (photolyase-negative) triple mutant is used for assay, lethal radiations are detected from all lamps, and single-hit exponential inactivation rates rather closely correlate to amount of directly measured UVB + UVC output of each pair of lamps. Although all lamps tested may meet international and Unite States standards for radiation safely, optimal practices in lamp manufacture are clearly capable of decreasing human exposure to indoor UV light. 38 refs., 3 figs., 1 tab

  2. Highly efficient exciplex organic light-emitting diodes using thermally activated delayed fluorescent emitters as donor and acceptor materials

    Science.gov (United States)

    Jeon, Sang Kyu; Yook, Kyoung Soo; Lee, Jun Yeob

    2016-06-01

    Highly efficient exciplex type organic light-emitting diodes were developed using thermally activated delayed fluorescent emitters as donors and acceptors of an exciplex. Blue emitting bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (DMAC-DPS) was a donor and 9,9‧-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenylene)bis(9H-carbazole) (DDCzTrz) and 9,9‧,9″-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)benzene-1,2,3-triyl)tris(9H-carbazole) (TCzTrz) were acceptor materials. The exciplexes of DMAC-DPS:TCzTrz and DMAC-DPS:DDCzTrz resulted in high photoluminescence quantum yield and high quantum efficiency in the green exciplex organic light-emitting diodes. High quantum efficiencies of 13.4% and 15.3% were obtained in the DMAC-DPS:DDCzTrz and DMAC-DPS:TCzTrz exciplex devices.

  3. Color-tunable and stable-efficiency white organic light-emitting diode fabricated with fluorescent-phosphorescent emission layers

    International Nuclear Information System (INIS)

    Yang, Su-Hua; Shih, Po-Jen; Wu, Wen-Jie; Huang, Yi-Hua

    2013-01-01

    White organic light emitting diodes (OLEDs) were fabricated for color-tunable lighting applications. Fluorescent and phosphorescent hybrid emission layers (EMLs) were used to enhance the luminance and stability of the devices, which have blue-EML/CBP interlayer/green-EML/phosphorescent-sensitized-EML/red-EML structures. The influence of the composition and structure of the EMLs on the electroluminescence properties of the devices were investigated from the viewpoint of their emission spectra. The possible exciton harvesting, diffusion, transport, and annihilation processes occurring in the EMLs were also evaluated. A maximum luminance intensity of 7400 cd/m 2 and a highly stable current efficiency of 3.2 cd/A were obtained. Good color tunability was achieved for the white OLEDs; the chromatic coordinates linearly shifted from pure white (0.300, 0.398) to cold white (0.261, 0.367) when the applied voltage was varied from 10 to 14 V. -- Highlights: • Exciton harvesting, diffusion, transport, and annihilation processes were evaluated. • The electroluminescence properties were investigated from the viewpoint of the emission spectra. • Good color tunability and stable-efficiency were achieved for the white OLEDs

  4. Ultraviolet radiation levels associated with the use of fluorescent general lighting, UV-A and UV-B lamps in the workplace and home

    CERN Document Server

    Whillock, M; MacKinlay, Alistair F; Mundy, S J; Todd, Carl David

    1988-01-01

    A detailed programme of measurements was undertaken by NRPB to determine the ultraviolet irradiance levels likely to be encountered in the workplace and in the home, where fluorescent lighting is used. Assessments have been made of the possible potential risk of the induction of acute effects (photokeratitis, erythema) and of inducing malignant melanoma and non-malignant melanoma skin cancers resulting from exposure to commonly used fluorescent lamps. The optical absorption properties of materials commonly used in diffusers and controllers in commercial and domestic lighting units were also measured. Irradiance data, both weighted (for biological effectiveness) and unweighted, for various lamp types are presented in the report, together with some typical spectral output distributions. The results show that at commonly used illumination levels the UVR emissions from general and special fluorescent lamps presented neither an acute nor a significant chronic hazard. High UV-B emission levels were measured from 'U...

  5. The evaluation of a novel method comparing quantitative light-induced fluorescence (QLF) with spectrophotometry to assess staining and bleaching of teeth

    NARCIS (Netherlands)

    Adeyemi, A.A.; Jarad, F.D.; de Josselin de Jong, E.; Pender, N.; Higham, S.M.

    2010-01-01

    This study reports the development and evaluation of a novel method using quantitative light-induced fluorescence (QLF), which enables its use for quantifying and assessing whole tooth surface staining and tooth whitening. The method was compared with a spectrophotometer to assess reliability. Two

  6. Generation of fluorescence quenchers from the triplet states of chlorophylls in the major light-harvesting complex II from green plants

    NARCIS (Netherlands)

    Barzda, V.; Vengris, M.; Valkunas, L.; van Amerongen, H.; van Grondelle, R.

    2000-01-01

    Laser flash-induced changes of the fluorescence yield were studied in aggregates of light-harvesting complex II (LHCII) on a time scale ranging from microseconds to seconds. Carotenoid (Car) and chlorophyll (Chl) triplet states, decaying with lifetimes of several microseconds and hundreds of

  7. Malfunctioning Plastic Biliary Endoprosthesis: Percutaneous Transhepatic Balloon Pulling Technique

    Directory of Open Access Journals (Sweden)

    Umberto G. Rossi

    2013-01-01

    Full Text Available Percutaneous transhepatic removal techniques for malfunctioning plastic biliary endoprosthesis are considered safe and efficient second-line strategies, when endoscopic procedures are not feasible. We describe the percutaneous transhepatic balloon pulling technique in a patient with an unresectable malignant hilar cholangiocarcinoma.

  8. Dealing with Malfunction: Locus of Control in Web-Conferencing

    Science.gov (United States)

    Klebl, Michael

    2014-01-01

    This paper considers how students deal with malfunctions that occur during the use of web conferencing systems in learning arrangements. In a survey among participants in online courses that make use of a web-conferencing system (N = 129), the relationship between a preference for internal or external locus of control and the perception of…

  9. Excessive heat removal due to feedwater system malfunction

    International Nuclear Information System (INIS)

    Beader, D.; Peterlin, G.

    1986-01-01

    Excessive heat removal transient of the Krsko Nuclear Power Plant, caused by steam generators feedwater system malfunctions was simulated by RELAP5/MOD1 computer code. The results are increase of power and reactor scram caused by high-high steam generator level. (author)

  10. 40 CFR 63.1111 - Startup, shutdown, and malfunction.

    Science.gov (United States)

    2010-07-01

    ... corrective action taken to restore malfunctioning process and air pollution control equipment to its normal... such affected source (including associated air pollution control equipment and CPMS) in a manner consistent with safety and good air pollution control practices for minimizing emissions to the extent...

  11. Enhancement and Quenching of Fluorescence by Silver Nanoparticles in Organic Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Ying-Chung Chen

    2013-01-01

    Full Text Available The influence of silver nanoparticles (SNPs on the performance of organic light-emitting diodes (OLEDs is investigated in this study. The SNPs are introduced between the electron-transport layers by means of thermal evaporation. SNPs are found to have the surface plasmon resonance at wavelength 525 nm when the mean particle size of SNPs is 34 nm. The optimized OLED, in terms of the spacing between the emitting layer and SNPs, is found to have the maximum luminance 2.4 times higher than that in the OLED without SNPs. The energy transfer between exciton and surface plasmons with the different spacing distances has been studied.

  12. Design and evaluation of capillary coupled with optical fiber light-emitting diode induced fluorescence detection for capillary electrophoresis.

    Science.gov (United States)

    Ji, Hongyun; Li, Meng; Guo, Lihong; Yuan, Hongyan; Wang, Chunling; Xiao, Dan

    2013-09-01

    A new detector, capillary coupled with optical fiber LED-induced fluorescence detector (CCOF-LED-IFD, using CCOF for short), is introduced for CE. The strategy of the present work was that the optical fiber and separation capillary were, in the parallel direction, fastened in a fixation capillary with larger inner diameter. By employing larger inner diameter, the fixation capillary allowed the large diameter of the optical fiber to be inserted into it. By transmitting an enhanced excitation light through the optical fiber, the detection sensitivity was improved. The advantages of the CCOF-CE system were validated by the detection of riboflavin, and the results were compared to those obtained by the in-capillary common optical fiber LED-induced fluorescence detector (IC-COF-LED-IFD, using COF for short). The LODs of CCOF-CE and COF-CE were 0.29 nM and 11.0 nM (S/N = 3), respectively. The intraday (n = 6) repeatability and interday (n = 6) reproducibility of migration time and corresponding peak area for both types of CE were all less than 1.10 and 3.30%, respectively. The accuracy of the proposed method was judged by employing standard addition method, and recoveries obtained were in the range of 98.0-102.4%. The results indicated that the sensitivity of the proposed system was largely improved, and that its reproducibility and accuracy were satisfactory. The proposed system was successfully applied to separate and determine riboflavin in real sample. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Determination of metallothioneins by fluorescence and resonance light scattering strategies based on ciprofloxacin–Cu(II) system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lu [College of Public Health, University of South China, Hengyang 421001 (China); Wang, Yong-Sheng, E-mail: yongsheng.w@tom.com [College of Public Health, University of South China, Hengyang 421001 (China); Xue, Jin-Hua; Yang, Hui-Xian; Li, Qiu; Zhou, Bin; Wang, Jia-Cheng; Yin, Ji-Cheng; Wang, Yong-Song [College of Public Health, University of South China, Hengyang 421001 (China); Xiao, Xi-Lin [College of Chemistry and Chemical Engineering, University of South China, Hengyang 421001 (China)

    2013-06-15

    Based on ciprofloxacin (CIP)–Cu(II) system, the novel methods for the detection of metallothioneins (MTs) have been developed by fluorescence (FL) and resonance light scattering (RLS) strategies. The FL strategy avoids the label and derivatization steps in common methods, while the RLS strategy can be applied for determining bio-macromolecules and small molecules without native fluorescence. The response signals linearly correlated with the concentration of MTs over the ranges of 1.03×10{sup −8}–1.23×10{sup −6} mol L{sup −1} for FL, and of 2.56×10{sup −7}–1.54×10{sup −6} mol L{sup −1} for RLS. The limits of detection (LOD) are 3.1×10{sup −9} mol L{sup −1} for FL and 7.68×10{sup −8} mol L{sup −1} for RLS. This study represents the comparison of these two methods using the same CIP–Cu{sup 2+}–MTs system. They not only allow practical application for MTs detection but also serve as a potential choice for the operators according to their concrete needs. In addition, the mechanisms for FL and RLS enhancement of the system were also discussed. -- Highlights: ► Determination of MTs was developed based on CIP–Cu(II) system by FL and RLS strategies. ► FL strategy provides lower limit of detection and wider linear range, and avoids the label and derivatization steps. ► RLS strategy can be applied for determining bio-macromolecules and small molecules. ► The mechanism of interaction of MTs with CIP–Cu(II) chelate was discussed.

  14. Photocatalytic oxidation removal of Hg"0 using ternary Ag/AgI-Ag_2CO_3 hybrids in wet scrubbing process under fluorescent light

    International Nuclear Information System (INIS)

    Zhang, Anchao; Zhang, Lixiang; Chen, Xiaozhuan; Zhu, Qifeng; Liu, Zhichao; Xiang, Jun

    2017-01-01

    Highlights: • Ag/AgI-Ag_2CO_3 hybrids were employed for Hg"0 removal under fluorescent light. • Superoxide radical (·O_2"−) played a key role in Hg"0 removal. • NO exhibited a significant effect on Hg"0 removal in comparison to SO_2. • The mechanism for enhanced Hg"0 removal over Ag/AgI-Ag_2CO_3 was proposed. - Abstract: A series of ternary Ag/AgI-Ag_2CO_3 photocatalysts synthesized using a facile coprecipitation method were employed to investigate their performances of Hg"0 removal in a wet scrubbing reactor. The hybrids were characterized by N_2 adsorption-desorption, XRD, SEM-EDS, HRTEM, XPS, DRS and ESR. The photocatalytic activities of Hg"0 removal were evaluated under fluorescent light. The results showed that AgI content, fluorescent light irradiation, reaction temperature all showed significant influences on Hg"0 removal. NO exhibited significant effect on Hg"0 removal in comparison to SO_2. Among these ternary Ag/AgI-Ag_2CO_3 hybrids, Ag/AgI(0.1)-Ag_2CO_3 showed the highest Hg"0 removal efficiency, which could be ascribed to the effective separation of photogenerated electron-hole pairs between AgI and Ag_2CO_3 and the surface plasmon resonance (SPR) effect in the visible region by metallic silver nanoparticles (Ag"0 NPs). The trapping studies of reactive radicals showed that the superoxide radicals (·O_2"−) may play a key role in Hg"0 removal under fluorescent light. According to the experimental and characterization results, a possible photocatalytic oxidation mechanism for enhanced Hg"0 removal over Ag/AgI(0.1)-Ag_2CO_3 hybrid under fluorescent light was proposed.

  15. CH3 NH3 PbBr3 Perovskite Nanocrystals as Efficient Light-Harvesting Antenna for Fluorescence Resonance Energy Transfer.

    Science.gov (United States)

    Muthu, Chinnadurai; Vijayan, Anuja; Nair, Vijayakumar C

    2017-05-04

    Hybrid perovskites have created enormous research interest as a low-cost material for high-performance photovoltaic devices, light-emitting diodes, photodetectors, memory devices and sensors. Perovskite materials in nanocrystal form that display intense luminescence due to the quantum confinement effect were found to be particularly suitable for most of these applications. However, the potential use of perovskite nanocrystals as a light-harvesting antenna for possible applications in artificial photosynthesis systems is not yet explored. In the present work, we study the light-harvesting antenna properties of luminescent methylammonium lead bromide (CH 3 NH 3 PbBr 3 )-based perovskite nanocrystals using fluorescent dyes (rhodamine B, rhodamine 101, and nile red) as energy acceptors. Our studies revealed that CH 3 NH 3 PbBr 3 nanocrystals are an excellent light-harvesting antenna, and efficient fluorescence resonance energy transfer occurs from the nanocrystals to fluorescent dyes. Further, the energy transfer efficiency is found to be highly dependent on the number of anchoring groups and binding ability of the dyes to the surface of the nanocrystals. These observations may have significant implications for perovskite-based light-harvesting devices and their possible use in artificial photosynthesis systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Prediction and design of efficient exciplex emitters for high-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes.

    Science.gov (United States)

    Liu, Xiao-Ke; Chen, Zhan; Zheng, Cai-Jun; Liu, Chuan-Lin; Lee, Chun-Sing; Li, Fan; Ou, Xue-Mei; Zhang, Xiao-Hong

    2015-04-08

    High-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes based on exciplex emitters are demonstrated. The best device, based on a TAPC:DPTPCz emitter, shows a high external quantum efficiency of 15.4%. Strategies for predicting and designing efficient exciplex emitters are also provided. This approach allow prediction and design of efficient exciplex emitters for achieving high-efficiency organic light-emitting diodes, for future use in displays and lighting applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Inducing fluorescence of uranyl acetate as a dual-purpose contrast agent for correlative light-electron microscopy with nanometre precision.

    Science.gov (United States)

    Tuijtel, Maarten W; Mulder, Aat A; Posthuma, Clara C; van der Hoeven, Barbara; Koster, Abraham J; Bárcena, Montserrat; Faas, Frank G A; Sharp, Thomas H

    2017-09-05

    Correlative light-electron microscopy (CLEM) combines the high spatial resolution of transmission electron microscopy (TEM) with the capability of fluorescence light microscopy (FLM) to locate rare or transient cellular events within a large field of view. CLEM is therefore a powerful technique to study cellular processes. Aligning images derived from both imaging modalities is a prerequisite to correlate the two microscopy data sets, and poor alignment can limit interpretability of the data. Here, we describe how uranyl acetate, a commonly-used contrast agent for TEM, can be induced to fluoresce brightly at cryogenic temperatures (-195 °C) and imaged by cryoFLM using standard filter sets. This dual-purpose contrast agent can be used as a general tool for CLEM, whereby the equivalent staining allows direct correlation between fluorescence and TEM images. We demonstrate the potential of this approach by performing multi-colour CLEM of cells containing equine arteritis virus proteins tagged with either green- or red-fluorescent protein, and achieve high-precision localization of virus-induced intracellular membrane modifications. Using uranyl acetate as a dual-purpose contrast agent, we achieve an image alignment precision of ~30 nm, twice as accurate as when using fiducial beads, which will be essential for combining TEM with the evolving field of super-resolution light microscopy.

  18. Efficient fluorescent red, green, and blue organic light-emitting devices with a blue host of spirobifluorene derivative

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.-H. [Department of Chemical and Material Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan (China)], E-mail: lerongho@yuntech.edu.tw; Huang, Y.-W.; Wang, Y.-Y. [Department of Chemical and Material Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan (China); Chang, H.-Y. [EChem Hightech CO., LTD, Hsin-Chu Industrial Park, Hu-Kou, Hsin-Chu, Taiwan (China)

    2008-06-02

    Efficient fluorescent blue, green, and red (RGB) organic light-emitting devices (OLEDs) were fabricated using a blue host material of pyrimidine-containing spirobifluorene derivative 2,7-bis[2-(4-tert-butylphenyl)pyrimidine-5-yl]-9,9'-spirobifluorene (TBPSF) doped with blue dye perylene, green dye 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H, 11H-benzo[l] pyrano[6,7,8-ij] quinolizin-11-one (C545T), and red dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) -4H-pyran (DCJTB), respectively. The brightness and current efficiency of the perylene doped blue device reached 10117 cd/m{sup 2} and 2.97 cd/A. Green emission of the C545T doped device reached 8500 cd/m{sup 2} and 13.0 cd/A. Red emission of the DCJTB doped device can be as high as 9000 cd/m{sup 2} and 2.0 cd/A, respectively. High color purity of the blue (Commission Internationale de L'Eclairage (CIE{sub x,y}) coordinates (CIE, x = 0.27, y = 0.24)), green (CIE, x = 0.19, y = 0.63) and red (CIE, x = 0.62, y = 0.37) emissions were achieved for RGB dyes doped TBPSF OLEDs. High brightness, large current efficiency, and good color purity of TBPSF-based RGB OLEDs were obtained by the configuration optimization device, such as inserting the hole and electron-injection materials, and suitable dopant content and light emitting layer thickness.

  19. White organic light-emitting devices based on blue fluorescent dye combined with dual sub-monolayer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huishan, E-mail: yanghuishan1697@163.com

    2013-10-15

    White organic light-emitting devices have been realized by using highly blue fluorescent dye 4,4′-Bis(2,2-diphenyl-ethen-1-yl)-4,4′-di-(tert-butyl)phenyl(p-TDPVBi) and [2-methyl-6-[2-(2, 3,6,7-tetrahydro-1H, red fluorescent dye 5H-benzo[ij] quinolizin-9-yl) ethenyl]-4H-pyran-4-ylidene] propane-dinitrile(DCM2), together with well known green fluorescent dye quinacridone (QAD). The fabrication of multilayer WOLEDs did not involve the hard-to-control doping process. The structure of the device is ITO/m-MTDATA (45 nm)/NPB(8 nm)/p-TDPVBi(15 nm)/DCM2(x nm)/Alq{sub 3} (5 nm)/QAD(y nm)/Alq{sub 3}(55 nm)/LiF(1 nm)/Al, where 4,4′,4′′-tris{N,-(3-methylphenyl)-N-phenylamine}triphenylamine (m-MTDATA) acts as a hole injection layer, N,N′-bis-(1-naphthyl)-N, N′-diphenyl-1, 1′-biph-enyl-4, 4′-diamine (NPB) acts as a hole transport layer, p-TDPVBi acts as a blue emitting layer, DCM2 acts as a red emitting layer, QAD acts as a green emitting layer, tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) acts as an electron transport layer, and WOLEDs of devices A, B, C and D are different in layer thickness of DCM2 and QAD, respectively. To change the thickness of dual sub-monolayer DCM2 and QAD, the WOLEDs were obtained. When x, y=0.05, 0.1, the Commission Internationale de 1’Eclairage (CIE) coordinates of the device change from (0.4458, 0.4589) at 3 V to (0.3137, 0.3455) at 12 V that are well in the white region, and the color temperature and color rendering index were 5348 K and 85 at 8 V, respectively. Its maximum luminance was 35260 cd/m{sup 2} at 12 V, and maximum current efficiency and maximum power efficiency were 13.54 cd/A at 12 V and 6.68 lm/W at 5 V, respectively. Moreover, the current efficiency is largely insensitive to the applied voltage. The electroluminescence intensity of white EL devices varied only little at deferent dual sub-monolayer. Device D exhibited relatively high color rendering index (CRI) in the range of 88–90, which was essentially

  20. Use of invisible near infrared light fluorescence with indocyanine green and methylene blue in urology. Part 2.

    Science.gov (United States)

    Polom, Wojciech; Markuszewski, Marcin; Rho, Young Soo; Matuszewski, Marcin

    2014-01-01

    In the second part of this paper, concerning the use of invisible near infrared light (NIR) fluorescence with indocyanine green (ICG) and methylene blue (MB) in urology, other possible uses of this new technique will be presented. In kidney transplantation, this concerns allograft perfusion and real time NIR-guided angiography; moreover, perfusion angiography of tissue flaps, NIRF visualization of ureters, NIR-guided visualization of urinary calcifications, NIRF in male infertility and semen quality assessment. In this part, we have also analysed cancer targeting and imaging fluorophores as well as cost benefits associated with the use of these new techniques. PubMed and Medline databases were searched for ICG and MB use in urological settings, along with data published in abstracts of urological conferences. Although NIR-guided ICG and MB are still in their initial phases, there have been significant developments in a few more major domains of urology, including 1) kidney transplantation: kidney allograft perfusion and vessel reconstruction; 2) angiography perfusion of tissue flaps; 3) visualization of ureters; 4) visualization of urinary calcifications; and 5) NIRF in male infertility and semen quality assessment. Near infrared technology in urology is at its early stages. More studies are needed to assess the true potential and limitations of the technology. Initial studies show that this pioneering tool may influence various aspects of urology.

  1. Non-rigid contour-to-pixel registration of photographic and quantitative light-induced fluorescence imaging of decalcified teeth

    Science.gov (United States)

    Berkels, Benjamin; Deserno, Thomas; Ehrlich, Eva E.; Fritz, Ulrike B.; Sirazitdinova, Ekaterina; Tatano, Rosalia

    2016-03-01

    Quantitative light-induced fluorescence (QLF) is widely used to assess the damage of a tooth due to decalcification. In digital photographs, decalcification appears as white spot lesions, i.e. white spots on the tooth surface. We propose a novel multimodal registration approach for the matching of digital photographs and QLF images of decalcified teeth. The registration is based on the idea of contour-to-pixel matching. Here, the curve, which represents the shape of the tooth, is extracted from the QLF image using a contour segmentation by binarization and morphological processing. This curve is aligned to the photo with a non-rigid variational registration approach. Thus, the registration problem is formulated as minimization problem with an objective function that consists of a data term and a regularizer for the deformation. To construct the data term, the photo is pointwise classified into tooth and non-tooth regions. Then, the signed distance function of the tooth region allows to measure the mismatch between curve and photo. As regularizer a higher order, linear elastic prior is used. The resulting minimization problem is solved numerically using bilinear Finite Elements for the spatial discretization and the Gauss-Newton algorithm. The evaluation is based on 150 image pairs, where an average of 5 teeth have been captured from 32 subjects. All registrations have been confirmed correctly by a dental expert. The contour-to-pixel methods can directly be used in 3D for surface-to-voxel tasks.

  2. Multiple effects of fluorescent light on repair of ultraviolet-induced DNA lesions in cultured goldfish cells

    International Nuclear Information System (INIS)

    Uchida, Nobuhiro; Mitani, Hiroshi; Shima, Akihiro

    1995-01-01

    It is known that fluorescent light illumination prior to UV irradiation (FL preillumination) of cultured fish cells increases photorepair (PR) ability. In the present study, it was found that FL preillumination also enhanced UV resistance of logarithmically growing cells in the dark. This enhancement of UV resistance differs from induction of PR because it was not suppressed by cyclohexamide (CH) and it occurred immediately after FL preillumination. The effects of FL preillumination on repair of UV-induced DNA lesions in the dark were examined by an endonuclease-sensitive site assay to measure the repair of cyclobutyl pyrimidine dimers, and by enzyme-linked immunosorbent assay to quantitate the repair of (6-4) photoproducts. It was found that excision repair ability for (6-4) photoproducts in the genome overall was increased by FL preillumination. Moreover, a decrease in (6-4) photoproducts by FL illumination immediately after UV irradiation of the cells was found, the decrement being enhanced by FL preillumination with or without CH. (author)

  3. Multiple effects of fluorescent light on repair of ultraviolet-induced DNA lesions in cultured goldfish cells

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Nobuhiro; Mitani, Hiroshi; Shima, Akihiro [Tokyo Univ. (Japan). Lab. of Radiation Biology

    1995-01-01

    It is known that fluorescent light illumination prior to UV irradiation (FL preillumination) of cultured fish cells increases photorepair (PR) ability. In the present study, it was found that FL preillumination also enhanced UV resistance of logarithmically growing cells in the dark. This enhancement of UV resistance differs from induction of PR because it was not suppressed by cyclohexamide (CH) and it occurred immediately after FL preillumination. The effects of FL preillumination on repair of UV-induced DNA lesions in the dark were examined by an endonuclease-sensitive site assay to measure the repair of cyclobutyl pyrimidine dimers, and by enzyme-linked immunosorbent assay to quantitate the repair of (6-4) photoproducts. It was found that excision repair ability for (6-4) photoproducts in the genome overall was increased by FL preillumination. Moreover, a decrease in (6-4) photoproducts by FL illumination immediately after UV irradiation of the cells was found, the decrement being enhanced by FL preillumination with or without CH. (author).

  4. Classification system for reporting events involving human malfunctions

    International Nuclear Information System (INIS)

    Rasmussen, J.; Pedersen, O.M.; Mancini, G.; Carnino, A.; Griffon, M.; Gagnolet, P.

    1981-03-01

    The report describes a set of categories for reporting industrial incidents and events involving human malfunction. The classification system aims at ensuring information adequate for improvement of human work situations and man-machine interface systems and for attempts to quantify ''human error'' rates. The classification system has a multifacetted non-hierarchial structure and its compatibility with Ispra's ERDS classification is described. The collection of the information in general and for quantification purposes are discussed. 24 categories, 12 of which being human factors oriented, are listed with their respective subcategories, and comments are given. Underlying models of human data processes and their typical malfunctions and of a human decision sequence are described. (author)

  5. Classification system for reporting events involving human malfunctions

    DEFF Research Database (Denmark)

    Rasmussen, Jens; Pedersen, O.M.; Mancini, G.

    1981-01-01

    The report describes a set of categories for reporting indus-trial incidents and events involving human malfunction. The classification system aims at ensuring information adequate for improvement of human work situations and man-machine interface systems and for attempts to quantify "human error......" rates. The classification system has a multifacetted non-hierarchical struc-ture and its compatibility with Isprals ERDS classification is described. The collection of the information in general and for quantification purposes are discussed. 24 categories, 12 of which being human factors oriented......, are listed with their respective subcategories, and comments are given. Underlying models of human data processes and their typical malfunc-tions and of a human decision sequence are described....

  6. Analysis of Light Gathering Abilities of Dynamically Solidified Micro-lenses, and Their Implementation to Improve Sensitivity of Fluorescent PCR Micro-detectors.

    Science.gov (United States)

    Wu, Jian; Guo, Wei; Wang, Chunyan; Yu, Kuanxin; Chen, Tao; Li, Yinghui

    2015-06-01

    Fluorescent polymerase chain reaction (PCR) is becoming the preferred method of quantitative analysis due to its high specificity and sensitivity. We propose to use a new kind of micro-lens, dynamically solidified with optic glue, to improve the sensitivity of fluorescent PCR micro-detector. We developed light ray track equations for these lenses and used them to calculate relative light intensity distribution curve for stimulation lenses and illumination point probability distribution curve for detection lenses. We manufactured dynamically solidified micro-lenses using optic glue NOA61, and measured their light gathering ability. Lenses with radius/thickness (R/H) ratio of 4 reached light focusing ratio of 3.85 (stimulation lens) and photon collection efficiency of 0.86 (detection lens). We then used dynamically solidified lenses in PCR fluorescence micro-detector and analyzed their effect on the detector sensitivity. We showed that the use of dynamically solidified micro-lenses with R/H = 4 resulted in over 4.4-fold increased sensitivity of the detector.

  7. Lighting.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-09-01

    Since lighting accounts for about one-third of the energy used in commercial buildings, there is opportunity to conserve. There are two ways to reduce lighting energy use: modify lighting systems so that they used less electricity and/or reduce the number of hours the lights are used. This booklet presents a number of ways to do both. Topics covered include: reassessing lighting levels, reducing lighting levels, increasing bulb & fixture efficiency, using controls to regulate lighting, and taking advantage of daylight.

  8. Simultaneous fluorescence light-up and selective multicolor nucleobase recognition based on sequence-dependent strong binding of berberine to DNA abasic site.

    Science.gov (United States)

    Wu, Fei; Shao, Yong; Ma, Kun; Cui, Qinghua; Liu, Guiying; Xu, Shujuan

    2012-04-28

    Label-free DNA nucleobase recognition by fluorescent small molecules has received much attention due to its simplicity in mutation identification and drug screening. However, sequence-dependent fluorescence light-up nucleobase recognition and multicolor emission with individual emission energy for individual nucleobases have been seldom realized. Herein, an abasic site (AP site) in a DNA duplex was employed as a binding field for berberine, one of isoquinoline alkaloids. Unlike weak binding of berberine to the fully matched DNAs without the AP site, strong binding of berberine to the AP site occurs and the berberine's fluorescence light-up behaviors are highly dependent on the target nucleobases opposite the AP site in which the targets thymine and cytosine produce dual emission bands, while the targets guanine and adenine only give a single emission band. Furthermore, more intense emissions are observed for the target pyrimidines than purines. The flanking bases of the AP site also produce some modifications of the berberine's emission behavior. The binding selectivity of berberine at the AP site is also confirmed by measurements of fluorescence resonance energy transfer, excited-state lifetime, DNA melting and fluorescence quenching by ferrocyanide and sodium chloride. It is expected that the target pyrimidines cause berberine to be stacked well within DNA base pairs near the AP site, which results in a strong resonance coupling of the electronic transitions to the particular vibration mode to produce the dual emissions. The fluorescent signal-on and emission energy-modulated sensing for nucleobases based on this fluorophore is substantially advantageous over the previously used fluorophores. We expect that this approach will be developed as a practical device for differentiating pyrimidines from purines by positioning an AP site toward a target that is available for readout by this alkaloid probe. This journal is © The Royal Society of Chemistry 2012

  9. Utilization of an Airborne Plant Chlorophyll Imaging System for Detection of Septic System Malfunction

    Science.gov (United States)

    Spiering, Bruce A.; Carter, Gregory A.

    2001-01-01

    Malfunctioning, or leaking, sewer systems increase the supply of water and nutrients to surface vegetation. Excess nutrients and harmful bacteria in the effluent pollute ground water and local water bodies and are dangerous to humans and the aquatic ecosystems. An airborne multispectral plant chlorophyll imaging system (PCIS) was used to identify growth patterns in the vegetation covering onsite and public sewer systems. The objective was to evaluate overall performance of the PCIS as well as to determine the best operational configuration for this application. The imaging system was flown in a light aircraft over selected locations Mobile County, Alabama. Calibration panels were used to help characterize instrument performance. Results demonstrated that the PCIS performed well and was capable of detecting septic leakage patterns from altitudes as high as 915 m. From 915 m, 6 of 18 sites were suspected to have sewage leakage. Subsequent ground inspections confirmed leakage on 3 of the 6 sites. From 610 m, 3 of 8 known leakage sites were detected. Tree cover and shadows near residential structures prevented detection of several known malfunctioning systems. Also some leakages known to occur in clear areas were not detected. False detections occurred in areas characterized by surface water drainage problems or recent excavation.

  10. Light-Induced Fluorescence Modulation of Quantum Dot-Crystal Violet Conjugates: Stochastic Off-On-Off Cycles for Multicolor Patterning and Super-Resolution.

    Science.gov (United States)

    Jung, Sungwook; Park, Joonhyuck; Bang, Jiwon; Kim, Jae-Yeol; Kim, Cheolhee; Jeon, Yongmoon; Lee, Seung Hwan; Jin, Ho; Choi, Sukyung; Kim, Bomi; Lee, Woo Jin; Pack, Chan-Gi; Lee, Jong-Bong; Lee, Nam Ki; Kim, Sungjee

    2017-06-07

    Photoswitching or modulation of quantum dots (QDs) can be promising for many fields that include display, memory, and super-resolution imaging. However, such modulations have mostly relied on photomodulations of conjugated molecules in QD vicinity, which typically require high power of high energy photons at UV. We report a visible light-induced facile modulation route for QD-dye conjugates. QD crystal violets conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs showed a single cycle of emission burst as they go through three stages of (i) initially quenched "off" to (ii) photoactivated "on" as the result of chemical change of CVs induced by photoelectrons from QD and (iii) back to photodarkened "off" by radical-associated reactions. Multicolor on-demand photopatterning was demonstrated using QD-CV solid films. QD-CVs were introduced into cells, and excitation with visible light yielded photomodulation from "off" to "on" and "off" by nearly ten fold. Individual photoluminescence dynamics of QD-CVs was investigated using fluorescence correlation spectroscopy and single QD emission analysis, which revealed temporally stochastic photoactivations and photodarkenings. Exploiting the stochastic fluorescence burst of QD-CVs, simultaneous multicolor super-resolution localizations were demonstrated.

  11. Transfer of ultraviolet photon energy into fluorescent light in the visible path represents a new and efficient protection mechanism of sunscreens

    Science.gov (United States)

    Vergou, Theognosia; Patzelt, Alexa; Richter, Heike; Schanzer, Sabine; Zastrow, Leonhard; Golz, Karin; Doucet, Olivier; Antoniou, Christina; Sterry, Wolfram; Lademann, Juergen

    2011-10-01

    The development of sunscreens with high sun protection factor (SPF) values but low filter concentrations is the ultimate goal. The purpose of the present study was to investigate why a sunscreen spray and cream with different concentrations of the same UV-filters provided the same SPF. Therefore, the homogeneity of the distribution of both sunscreens was investigated by laser scanning microscopy (LSM) and tape stripping (TS). Additionally, the energy transfer mechanisms of the sunscreens on the skin were analyzed. The TS and LSM showed a better homogeneity of the distribution of the spray. With Wood's light, a total absorption of the irradiation was detected in the spray area. In contrast, after cream treatment, an intensive fluorescent signal was observed. It was demonstrated that this fluorescent signal was caused by nonthermal energy transferred from the UV-filters to one compound of the cream releasing its excitation energy by fluorescence. This nonthermal energy transfer seemed to be the reason for the high efficiency of the cream, which is subjected to thermal relaxation. The transfer of UV photon energy into fluorescent light represents a new approach to increase the efficiency of sunscreens and could form the basis for a new generation of sunscreens.

  12. t-Butyl group-substituted triphenylamine-containing orange-red fluorescent emitters for organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kum Hee; Kim, Chi Sik [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

    2012-03-30

    Efficient orange-red fluorescent compounds, 4-(dicyanomethylene)-2-adamantyl-6-(4-(N-(4-tert-butylphenyl) -N-(3,5-di-tert-butylphenyl)amino)benzene)vinyl-4H-pyran (DCATP) and 2,6-bis[4-(N-(4-tert-butylphenyl)-N-(3,5-di-tert-butylphenyl)amino)benzene] vinyl-4-(dicyanomethylene)-4H-pyran (BDCTP) containing the tert-butylated triphenylamine in donor moieties, were synthesized and characterized. In these red emitters, bulky groups, such as t-butyl group and adamantane were introduced to increase the steric hindrance between the red emitters. In particular, an efficient orange-red device containing the emitter DCATP as a dopant showed a luminous and power efficiency of 6.87 cd/A and 2.70 lm/W, respectively, at 20 mA/cm{sup 2} with the CIE coordinates of (0.48, 0.50) at 7.0 V. In addition, an efficient red organic light-emitting diode using BDCTP as a dopant exhibited a luminous and power efficiency of 2.30 cd/A and 1.31 lm/W, respectively, at 20 mA/cm{sup 2} and CIE coordinates of (0.61, 0.39). - Highlights: Black-Right-Pointing-Pointer Two orange-red emitters with t-butylated triphenylamine derivatives were studied. Black-Right-Pointing-Pointer We examine changes in electron D-A and electron D-A-D type in the terminal groups. Black-Right-Pointing-Pointer Electron D-A-D type material shows improved color chromaticity.

  13. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope

    OpenAIRE

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2015-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP pr...

  14. Remanagement of Singlet and Triplet Excitons in Single-Emissive-Layer Hybrid White Organic Light-Emitting Devices Using Thermally Activated Delayed Fluorescent Blue Exciplex.

    Science.gov (United States)

    Liu, Xiao-Ke; Chen, Zhan; Qing, Jian; Zhang, Wen-Jun; Wu, Bo; Tam, Hoi Lam; Zhu, Furong; Zhang, Xiao-Hong; Lee, Chun-Sing

    2015-11-25

    A high-performance hybrid white organic light-emitting device (WOLED) is demonstrated based on an efficient novel thermally activated delayed fluorescence (TADF) blue exciplex system. This device shows a low turn-on voltage of 2.5 V and maximum forward-viewing external quantum efficiency of 25.5%, which opens a new avenue for achieving high-performance hybrid WOLEDs with simple structures. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Differing sensitivity to fluorescent light in Chinese hamster cells containing equally incorporated quantities of BUdR versus IUdR

    International Nuclear Information System (INIS)

    Mitchell, J.B.; Morstyn, G.; Russo, A.; Kinsella, T.J.; Fornace, A. Jr.; McPherson, S.; Glatstein, E.

    1984-01-01

    Chinese hamster V79 cells that had incorporated approximately equal levels of either BUdR or IUdR into their DNA were found to be equal sensitizers to x rays. However, BUdR-substituted cells were much more sensitive to fluorescent light than IUdR-substituted cells, both on a cell survival basis and by the initial number of single strand DNA breaks induced. Since a major toxicity to the use of BUdR clinically has been light-induced skin rash, these data indicate that the use of IUdR clinically might cause less untoward toxicity but yet provide the same radiosensitization as BUdR

  16. Quantitative Light-induced Fluorescence-Digital as an oral hygiene evaluation tool to assess plaque accumulation and enamel demineralization in orthodontics.

    Science.gov (United States)

    Miller, Cara C; Burnside, Girvan; Higham, Susan M; Flannigan, Norah L

    2016-11-01

      To assess the use of Quantitative Light-induced Fluorescence-Digital as an oral hygiene evaluation tool during orthodontic treatment.   In this prospective, randomized clinical trial, 33 patients undergoing fixed orthodontic appliance treatment were randomly allocated to receive oral hygiene reinforcement at four consecutive appointments using either white light (WL) or Quantitative Light-induced Fluorescence-Digital (QLF) images, taken with a device, as visual aids. Oral hygiene was recorded assessing the QLF images for demineralization, by fluorescence loss (ΔF), and plaque coverage (ΔR30). A debriefing questionnaire ascertained patient perspectives.   There were no significant differences in demineralization (P  =  .56) or plaque accumulation (P  =  .82) between the WL and QLF groups from T0 to T4. There was no significant reduction in demineralization, ΔF, in the WL, or the QLF group from T0-T4 (P > .05); however, there was a significant reduction in ΔR30 plaque scores (P orthodontics. Oral hygiene reinforcement at consecutive appointments using WL or QLF images as visual aids is effective in reducing plaque coverage. In terms of clinical benefits, QLF and WL images are of similar effectiveness; however, patients preferred the QLF images.

  17. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

    Energy Technology Data Exchange (ETDEWEB)

    Robert, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection pour un rendement de detection maximal

  18. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

    Energy Technology Data Exchange (ETDEWEB)

    Robert, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection

  19. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  20. Light

    DEFF Research Database (Denmark)

    Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.

    2004-01-01

    This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...

  1. Observing Fluorescent Probes in Living Cells using a Low-Cost LED Flashlight Retrofitted to a Common Vintage Light Microscope

    Directory of Open Access Journals (Sweden)

    G. A. Babbitt

    2013-03-01

    Full Text Available While the application of molecular biological techniques based upon fluorescent probes has rapidly expanded over recent decades, the equipment cost of fluorescent microscopy has largely prevented its adoption in the college and high school classroom. We offer a simple solution to this problem by describing in detail how to build with simple tools, a fluorescent microscope using a common brand of colored LED flashlights and second-hand components of vintage Nikon microscopes. This extremely low cost solution is qualitatively compared to an expensive modern Zeiss system.

  2. Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments.

    Science.gov (United States)

    Gittins, John R; D'Angelo, Cecilia; Oswald, Franz; Edwards, Richard J; Wiedenmann, Jörg

    2015-01-01

    The genomic framework that enables corals to adjust to unfavourable conditions is crucial for coral reef survival in a rapidly changing climate. We have explored the striking intraspecific variability in the expression of coral pigments from the green fluorescent protein (GFP) family to elucidate the genomic basis for the plasticity of stress responses among reef corals. We show that multicopy genes can greatly increase the dynamic range over which corals can modulate transcript levels in response to the light environment. Using the red fluorescent protein amilFP597 in the coral Acropora millepora as a model, we demonstrate that its expression increases with light intensity, but both the minimal and maximal gene transcript levels vary markedly among colour morphs. The pigment concentration in the tissue of different morphs is strongly correlated with the number of gene copies with a particular promoter type. These findings indicate that colour polymorphism in reef corals can be caused by the environmentally regulated expression of multicopy genes. High-level expression of amilFP597 is correlated with reduced photodamage of zooxanthellae under acute light stress, supporting a photoprotective function of this pigment. The cluster of light-regulated pigment genes can enable corals to invest either in expensive high-level pigmentation, offering benefits under light stress, or to rely on low tissue pigment concentrations and use the conserved resources for other purposes, which is preferable in less light-exposed environments. The genomic framework described here allows corals to pursue different strategies to succeed in habitats with highly variable light stress levels. In summary, our results suggest that the intraspecific plasticity of reef corals' stress responses is larger than previously thought. © 2014 The Authors Molecular Ecology Published by John Wiley & Sons Ltd.

  3. Sun-induced chlorophyll fluorescence, photosynthesis, and light use efficiency of a soybean field from seasonally continuous measurements

    Science.gov (United States)

    Recent development of sun-induced chlorophyll fluorescence (SIF) technology is stimulating studies to remotely approximate canopy photosynthesis (measured as gross primary production, GPP). While multiple applications have advanced the empirical relationship between GPP and SIF, mechanistic understa...

  4. Elemental Composition of Mars Return Samples Using X-Ray Fluorescence Imaging at the National Synchrotron Light Source II

    Science.gov (United States)

    Thieme, J.; Hurowitz, J. A.; Schoonen, M. A.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

    2018-04-01

    NSLS-II at BNL provides a unique and critical capability to perform assessments of the elemental composition and the chemical state of Mars returned samples using synchrotron radiation X-ray fluorescence imaging and X-ray absorption spectroscopy.

  5. Fluorescent minerals--A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments.

    Science.gov (United States)

    Omairi, Tareq; Wainwright, Milton

    2015-07-01

    We propose that green algae (Chlorella variabilis and Dunaliella tertiolecta) and cyanobacteria (Synechococcus elongatus and Nostoc commune) can grow inside fluorescent rock minerals which convert damaging UV light to visible light, thereby allowing these organisms to survive and thrive in UV-rich environments without (or with limited) visible light, which would otherwise be inimical to them. The four microorganisms were incubated inside fluorescent rocks composed of fluorite, calcite and pyrite. The resultant growth was then measured following exposure to UV radiation, with the use of optical density and measurement of chlorophyll concentration. Results show that the microorganisms were shielded from harmful UV in these semi-transparent rocks, while at the same time benefiting from the fact that the minerals converted UV to visible light; this have been shown by a statistically significant increase in their growth, which although lower than when the cells were incubated in sunlight, was significantly higher than in controls incubated in the dark. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  6. Abundance and Night Hourly Dispersal of the Vesicating Beetles of the Genus Paederus (Coleoptera: Staphylinidae) Attracted to Fluorescent, Incandescent, and Black Light Sources in the Brazilian Savanna.

    Science.gov (United States)

    Lima, D C B; Costa, A A V; Silva, F S

    2015-01-01

    Paederus beetles are cosmopolitan medically important insects that cause dermatitis linearis to humans. In Brazil, despite the medical importance of these beetles, no studies focusing directly on the abundance and ecological features of harmful species exist. Therefore, this study aims at determining the abundance and the nocturnal hourly dispersal of Paederus species attracted to fluorescent, incandescent, and black light sources in the Brazilian savanna. Paederus species were captured from May to September for three consecutive years, between 2011 and 2013. The specimens were caught hourly, from 1800 to 0600 hours. Paederus beetles were attracted to incandescent, fluorescent, and black light lamps as light sources. A total of 959 individuals of five species were collected. The collected species were Paederus protensus Sharp (59.85%), Paederus columbinus Laporte de Castelnau (29.20%), Paederus mutans Sharp (7.09%), Paederus brasiliensis Erichson (3.34%), and Paederus ferus Erichson (0.52%). The black light was the most attractive source, and the darkest collecting point was the most representative for the number of individuals. The lowest catches were captured at full moon, and the highest catches were between 2200 and 0100 hours. Future investigations are needed to better understand the role of night temperature and soil humidity affecting the seasonal growth of Paederus beetle populations of northeastern Brazil. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Effect of fluorescent light on selected antioxidant compounds and antioxidant activity during storage of fresh-cut carambola (averrhoa carambola l.) fruit

    International Nuclear Information System (INIS)

    Zainudin, M.A.M.; Dek, M.S.P.; Anwar, F.

    2012-01-01

    The effects of fluorescent light on the availability of selected antioxidant compounds and antioxidant activity during storage of fresh-cut carambola (Averrhoa carambola L.) fruit were investigated. The samples of fresh-cut fruit, stored at 5 +- 1 deg. C, were exposed to fluorescent light (157 Lux) for 12 days. Total phenolic compounds (TPC) and ascorbic acid (AA) content of the processed fruit were analyzed using Folin-Ciocalteu reagent and high performance liquid chromatography (HPLC), respectively. Antioxidant activity of the fruit was assessed following 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging capacity and ferric-reducing antioxidant power (FRAP) assays. The results of the present study showed that light exposure did not exert any significant effect, while storage period significantly reduced the AA content of the fruits tested. On the other hand, with few exceptions, there were notable random changes, recorded in the TPC and antioxidant activity of the fruit as function of storage period and light exposure. (author)

  8. The Role of Light-Induced Fluorescence in the Treatment of Smooth Surface Carious Lesions with Icon Infiltration and the Results After 1 Year

    Directory of Open Access Journals (Sweden)

    Kabaktchieva R.

    2014-12-01

    Full Text Available Caries infiltration is a novel technique that brings out immediate esthetic improvement in the opacity of the white spot lesions. Light-induced fluorescence method is a modern caries diagnostic method. In this study SoproLife camera (Acteon, France was applied for diagnosing and follow-up of the results. The aims of this in vivo study are to test the role of light-induced fluorescence method (SoploLife camera in the diagnosis of non-cavitated smooth surfaces carious lesions (ICDAS codes 1 and 2 of primary and permanent teeth and in the follow-up period immediately after application, 6 months and 1 year after applying ICON material (DMG. Teeth: n = 90; primary teeth: 6 kids; n = 40 teeth; permanent teeth: 6 patients; n = 50 teeth. Visual examination by ICDAS without probe, dry for 10 s with 3-in-1 syringe using lightening; SoproLife camera (450 nm, digital photos. LIF method applied with SoproLife camera (Diagnostic mode with day light and blue light is more accurate than visual examination only when applied for single tooth diagnose. Moreover, LIF method for single tooth is more accurate in following up the effect of non-operative treatment of smooth surfaces lesions than using digital images. ICON is a material that stops the progression of non-cavitated smooth surfaces carious lesions in both primary and permanent teeth and make the aesthetic result better up to 1 year following the procedure.

  9. High-performance hybrid white organic light-emitting devices without interlayer between fluorescent and phosphorescent emissive regions.

    Science.gov (United States)

    Sun, Ning; Wang, Qi; Zhao, Yongbiao; Chen, Yonghua; Yang, Dezhi; Zhao, Fangchao; Chen, Jiangshan; Ma, Dongge

    2014-03-12

    By using mixed hosts with bipolar transport properties for blue emissive layers, a novel phosphorescence/fluorescence hybrid white OLED without using an interlayer between the fluorescent and phosphorescent regions is demonstrated. The peak EQE of the device is 19.0% and remains as high as 17.0% at the practical brightness of 1000 cd m(-2) . © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The erosive potential of commercially available mouthrinses on enamel as measured by Quantitative Light-induced Fluorescence (QLF).

    Science.gov (United States)

    Pretty, I A; Edgar, W M; Higham, S M

    2003-07-01

    Longitudinal in vitro. Previously extracted, caries free, human premolars were selected and prepared by gentle pumicing and coating in an acid-resistant nail-varnish save for an exposed enamel window on the buccal surface. Each was assigned to one of eight groups (six per group, 10 in positive control); positive control (citric acid, pH 2.7, F(-) 0 ppm), negative control (pH 7.0, F(-) 0 ppm) Listerine (pH 3.87, F(-) 0.021 ppm), Tesco Value (pH 6.05, F(-) 289.00 ppm), Tesco Total Care (pH 6.20, F(-) 313.84 ppm), Sainsbury's (pH 6.15, F(-) 365.75 ppm), Sensodyne (pH 6.12, F(-) 285.30 ppm) and Corsodyl (pH 5.65, F(-) 0 ppm). The titratable acid values (TAV) for each rinse were established using volume (ml) of 0.1 M NaOH to achieve pH 7. Fluoride values were obtained by ion selective electrode. The solutions were kept at 37 degrees C and gently agitated. Teeth were removed at hourly intervals for 15 h, air-dried and subjected to Quantitative Light-induced Fluorescence (QLF) examination by a blinded examiner and DeltaQ values recorded. At the conclusion of the study each of the positive control teeth and one from each other group were sectioned through the eroded lesion, ground and polished to 100 micrometers and subjected to transverse microradiography and DeltaZ recorded for validation. TAVs were: Listerine 2.45 L > Sainsbury's 0.35 ml >Tesco Total Care 0.14 ml > Tesco Value 0.08 ml > Corsodyl 0.10 ml >Sensodyne 0.9 ml. DeltaQ increased over time for the positive control, (0 h 0.2, 10 h 95.2, 15 h 152.3). Negative controls remained stable. The increase in DeltaQ for each rinse after 15 h was Listerine (9.3(+/-7.2)), Corsodyl (1.5(+/-1.2)), Tesco Value (1.8(+/-1.2)), Tesco Total Care (1.4(+/-1.1)), Sainsbury's (3.4(+/-2.2)), Sensodyne (0.9(+/-1.6)). TMR confirmed the presence/absence of erosive lesions. QLF effectively monitored erosion in the positive controls and lack of erosion in the NC. Only one mouthrinse (Listerine) caused any erosion compared to the negative

  11. Endolithic algae in living stony corals: algal concentrations under influence of depth-dependent light conditions and coral tissue fluorescence in Agaricia agaricites (L.) and Meandrina meandrites (L.) (Scleractinia, Anthozoa)

    NARCIS (Netherlands)

    Delvoye, Laurent

    1992-01-01

    DELVOYE, L., 1992. Endolithic algae in living stony corals: Algal concentrations under influence of depth-dependent light conditions and coral tissue fluorescence in Agaricia agaricites (L) and Meandrina meandrites (L.) (Sclereactinia, Anthozoa). Studies Nat. Hist. Caribbean Region 71, Amsterdam

  12. A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

    International Nuclear Information System (INIS)

    Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

    2013-01-01

    The new version MS2 of the in situ on-axis micro-spectrophotometer at the macromolecular crystallography beamline X10SA of the Swiss Light Source supports the concurrent acquisition of Raman, resonance Raman, fluorescence and UV/Vis absorption spectra along with diffraction data. The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years

  13. Ultraviolet radiation levels associated with the use of fluorescent general lighting, UV-A and UV-B lamps in the workplace and home

    International Nuclear Information System (INIS)

    Whillock, M.; Clark, I.E.; McKinlay, A.F.; Todd, C.D.; Mundy, S.J.

    1988-09-01

    A detailed programme of measurements was undertaken by NRPB to determine the ultraviolet irradiance levels likely to be encountered in the workplace and in the home, where fluorescent lighting is used. Assessments have been made of the possible potential risk of the induction of acute effects (photokeratitis, erythema) and of inducing malignant melanoma and non-malignant melanoma skin cancers resulting from exposure to commonly used fluorescent lamps. The optical absorption properties of materials commonly used in diffusers and controllers in commercial and domestic lighting units were also measured. Irradiance data, both weighted (for biological effectiveness) and unweighted, for various lamp types are presented in the report, together with some typical spectral output distributions. The results show that at commonly used illumination levels the UVR emissions from general and special fluorescent lamps presented neither an acute nor a significant chronic hazard. High UV-B emission levels were measured from 'UV-B' lamps used in this study, and exposure to these lamps would result in acute injury within a short time. Great care should be taken in the use of these lamps, and advice should be provided to workers to ensure safe working conditions and procedures. (author)

  14. A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source.

    Science.gov (United States)

    Pompidor, Guillaume; Dworkowski, Florian S N; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R

    2013-09-01

    The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years.

  15. A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

    Science.gov (United States)

    Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

    2013-01-01

    The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years. PMID:23955041

  16. Fluorescence of RbH and RbD formed by irradiating the mixed gases Rb + H2 and Rb + D2 with laser light

    International Nuclear Information System (INIS)

    Kato, Hajime; Toyosaka, Yukiko; Suzuki, Tomonari

    1985-01-01

    When a mixture of 85 Rb, 85 Rb 2 , and D 2 was irradiated by laser light at 5145 or 4880 A, small visible particles appeared and the fluorescence spectra were observed. By analyzing these spectra, we determined the rotational constants B v and the centrifugal distortion constants D v and H v for the X 1 Σ + and A 1 Σ + states of 85 RbD. By considering the isotopic dependence of the Dunham coefficients, we determined various molecular constants of 85 RbH whose values were in good agreement with the observed fluorescence spectra of 85 RbH excited by laser lines at 4762, 4765, and 4880 A. The process of RbH formation is discussed. (author)

  17. Risk factors and possible mechanisms of superior vena cava intravenous port malfunction.

    Science.gov (United States)

    Wu, Ching-Yang; Hu, Han-Chung; Ko, Po-Jen; Fu, Jui-Ying; Wu, Ching-Feng; Liu, Yun-Hen; Li, Hao-Jui; Kao, Tsung-Chi; Kao, Kuo-Chin; Yu, Sheng-Yueh; Chang, Chee-Jen; Hsieh, Hong-Chang

    2012-05-01

    To identify the risk factors leading to catheter malfunction. Reliable venous access is crucial for cancer patients. Malfunction of intravenous ports may lead to discontinuation of treatment and repeated interventions. We retrospectively reviewed the independent risk factors for catheter malfunction among patients receiving intravenous port implantations. A total of 1508 procedures were included from the calendar year 2006, and clinical data and chest plain films were analyzed. The patients were followed-up until June 30, 2010. For patients still alive, the last outpatient follow-up date was considered as the end point. For the remaining patients, the date of death or discharge against advice was considered as the end points. The risk factors for catheter malfunction were then evaluated. The intervention-free periods of the malfunction group and nonmalfunction group were 317 and 413 days, respectively. Statistical analyses showed that the Nut-Catheter Angle was the only risk factor for catheter malfunction (P = 0.001). A logistic model also confirmed that the Nut-Catheter Angle was the only risk factor for catheter malfunction (P risk for catheter malfunction. Catheter impingement caused by inadequate pocket creation and port implantation lead to compromised catheter lumen and difficulty flushing. The possibility of retained blood and medications increased thin thrombotic biofilm formation and medication precipitation. Catheter malfunctions can be avoided by using proper surgical techniques and adequate maintenance.

  18. Severe Intraoperative Hypercapnia Complicating an Unsual Malfunction of the Inner Tube of a Co-axial (BAIN'S Circuit

    Directory of Open Access Journals (Sweden)

    Youssef Emam Youssef

    2010-04-01

    Full Text Available The Bain's co-axial circuit system is fully established in general anaesthesia practice. It is favoured for its light weight and suitability for head and neck surgery. However, there are numerous published reports of malfunction of the inner tube of the Bain's co-axial circuit, with potentially lethal complications for the patient. This report presents a case in which a patient connected to a reused Bain's circuit (Datex-Ohmeda developed severe hypercapnia in the early intraoperative period due to unusual defect of the inner tube. This report tests and outlines the integrity of co-axial circuits and also reviews the available literature.

  19. Influence of dehydrated nanotubed titanic acid on charge transport and luminescent properties of polymer light-emitting diodes with fluorescent dye

    Science.gov (United States)

    Qian, Lei; Bera, Debasis; Jin, Zhen-Sheng; Du, Zu-Liang; Xu, Zheng; Teng, Feng; Liu, Wei

    2007-09-01

    In this paper, we discuss the influence of dehydrated nanotubed titanic acid (DNTA) on charge transport and luminescent properties of polymer light-emitting diodes (PLEDs) doped with fluorescent dye. Photoluminescence results confirm the efficient energy transfer from PVK to 4-(dicyanom-ethylene)-2- t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) and tris-(8-hydroxtquinoline) aluminum (Alq 3) in a DNTA-doped device. The device showed lower turn-on voltages and higher charge current by doping with DNTA, which also caused a shift in the exciton's recombination region.

  20. On the polyphasic quenching kinetics of chlorophyll a fluorescence in algae after light pulses of variable length

    Czech Academy of Sciences Publication Activity Database

    Vredenberg, W.; Prášil, Ondřej

    2013-01-01

    Roč. 117, 1-3 (2013), s. 321-337 ISSN 0166-8595 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Chlorophyll a fluorescence * Photosystem II * Quenching kinetics Subject RIV: EE - Microbiology, Virology Impact factor: 3.185, year: 2013

  1. Classification system for reporting events involving human malfunctions

    International Nuclear Information System (INIS)

    Rasmussen, J.; Pedersen, O.M.; Mancini, G.

    1981-01-01

    The report describes a set of categories for reporting industrial incidents and events involving human malfunction. The classification system aims at ensuring information adequate for improvement of human work situations and man-machine interface systems and for attempts to quantify ''human error'' rates. The classification system has a multifacetted non-hierarchical structure and its compatibility with Ispra's ERDS classification is described. The collection of the information in general and for quantification purposes are discussed. 24 categories, 12 of which being human factors-oriented, are listed with their respective subcategories, and comments are given. Underlying models of human data process and their typical malfuntions and of a human decision sequence are described. The work reported is a joint contribution to the CSNI Group of Experts on Human Error Data and Assessment

  2. Endoscopic removal of malfunctioning biliary self-expandable metallic stents.

    Science.gov (United States)

    Familiari, Pietro; Bulajic, Milutin; Mutignani, Massimiliano; Lee, Linda S; Spera, Gianluca; Spada, Cristiano; Tringali, Andrea; Costamagna, Guido

    2005-12-01

    Endoscopic removal of malfunctioning self-expandable metallic biliary stents (SEMS) is difficult and not well described. The aim of this study is to review the indications, the techniques, and the results of SEMS removal in a cohort of patients with malfunctioning stents. All patients who underwent an attempt at endoscopic removal of biliary SEMS over a 5-year period were retrospectively identified. The main indications for SEMS removal were the following: distal migration of the stent or impaction to the duodenum, impaction into the bile-duct wall, tissue ingrowth, and inappropriate length of the stent causing occlusion of intrahepatic ducts. SEMS were removed by using foreign-body forceps or polypectomy snares. Endoscopic removal of 39 SEMS (13 uncovered and 26 covered) was attempted in 29 patients (17 men; mean age, 66 years). SEMS extraction was attempted after a mean of 7.5 months (8.75 months standard deviation) post-SEMS insertion. Removal was successful in 20 patients (68.9%) and in 29 SEMS (74.3%). Covered SEMS were effectively removed more frequently than uncovered ones: 24 of 26 (92.3%) and 5 of 13 (38.4%), respectively (p < 0.05). No major complications were recorded. Multivariate analysis showed that the time interval between insertion and removal, SEMS length, stent-mesh design (zigzag vs. interlaced), and indication for removal were not predictive of success at stent removal. Endoscopic removal of biliary SEMS is feasible and safe in more than 70% of cases. Because only 38% of uncovered SEMS were removable, the presence of a stent covering is the only factor predictive of successful stent extraction. The presence of diffuse and severe ingrowth was the main feature limiting SEMS removal.

  3. X-ray Free Electron Laser Determination of Crystal Structures of Dark and Light States of a Reversibly Photoswitching Fluorescent Protein at Room Temperature

    Directory of Open Access Journals (Sweden)

    Christopher D. M. Hutchison

    2017-09-01

    Full Text Available The photochromic fluorescent protein Skylan-NS (Nonlinear Structured illumination variant mEos3.1H62L is a reversibly photoswitchable fluorescent protein which has an unilluminated/ground state with an anionic and cis chromophore conformation and high fluorescence quantum yield. Photo-conversion with illumination at 515 nm generates a meta-stable intermediate with neutral trans-chromophore structure that has a 4 h lifetime. We present X-ray crystal structures of the cis (on state at 1.9 Angstrom resolution and the trans (off state at a limiting resolution of 1.55 Angstrom from serial femtosecond crystallography experiments conducted at SPring-8 Angstrom Compact Free Electron Laser (SACLA at 7.0 keV and 10.5 keV, and at Linac Coherent Light Source (LCLS at 9.5 keV. We present a comparison of the data reduction and structure determination statistics for the two facilities which differ in flux, beam characteristics and detector technologies. Furthermore, a comparison of droplet on demand, grease injection and Gas Dynamic Virtual Nozzle (GDVN injection shows no significant differences in limiting resolution. The photoconversion of the on- to the off-state includes both internal and surface exposed protein structural changes, occurring in regions that lack crystal contacts in the orthorhombic crystal form.

  4. Harvesting Triplet Excitons with Exciplex Thermally Activated Delayed Fluorescence Emitters toward High Performance Heterostructured Organic Light-Emitting Field Effect Transistors.

    Science.gov (United States)

    Song, Li; Hu, Yongsheng; Liu, Zheqin; Lv, Ying; Guo, Xiaoyang; Liu, Xingyuan

    2017-01-25

    The utilization of triplet excitons plays a key role in obtaining high emission efficiency for organic electroluminescent devices. However, to date, only phosphorescent materials have been implemented to harvest the triplet excitons in the organic light-emitting field effect transistors (OLEFETs). In this work, we report the first incorporation of exciplex thermally activated delayed fluorescence (TADF) emitters in heterostructured OLEFETs to harvest the triplet excitons. By developing a new kind of exciplex TADF emitter constituted by m-MTDATA (4,4',4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine) as the donor and OXD-7 (1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene) as the acceptor, an exciton utilization efficiency of 74.3% for the devices was achieved. It is found that the injection barrier between hole transport layer and emission layer as well as the ratio between donor and acceptor would influence the external quantum efficiency (EQE) significantly. Devices with a maximum EQE of 3.76% which is far exceeding the reported results for devices with conventional fluorescent emitters were successfully demonstrated. Moreover, the EQE at high brightness even outperformed the result for organic light-emitting diode based on the same emitter. Our results demonstrate that the exciplex TADF emitters can be promising candidates to develop OLEFETs with high performance.

  5. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  6. Malfunction of the inner ear is the most frequent cause of dizziness

    DEFF Research Database (Denmark)

    Klokker, Mads; Vesterhauge, Søren

    2013-01-01

    Half of all dizziness patients suffer from a malfunction of the inner ear and benign paroxysmal positional vertigo causes 25-30% of these malfunctions. During the latest two decades new vestibular test equipment has been developed and has made it possible to refine the vestibular diagnoses...

  7. 33 CFR 149.125 - What are the requirements for the malfunction detection system?

    Science.gov (United States)

    2010-07-01

    ... malfunction detection system? 149.125 Section 149.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Pollution Prevention Equipment § 149.125 What are the requirements for the malfunction detection system? (a... Commandant (CG-5) will evaluate proposed leak-detection systems for natural gas on an individual basis. ...

  8. 40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing ...

  9. 40 CFR 63.2852 - What is a startup, shutdown, and malfunction plan?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What is a startup, shutdown, and... Production Compliance Requirements § 63.2852 What is a startup, shutdown, and malfunction plan? You must...)(2) malfunction period, or the § 63.2850(c)(2) or (d)(2) initial startup period. The SSM plan must...

  10. 40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3...

  11. 40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during CISWI unit startups, shutdowns, or malfunctions. (b) Each...

  12. 40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

  13. 40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

  14. Fluorescence Imaging Reveals Surface Contamination

    Science.gov (United States)

    Schirato, Richard; Polichar, Raulf

    1992-01-01

    In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

  15. Leaf gas exchange, chlorophyll fluorescence and pigment indexes of Eugenia uniflora L. in response to changes in light intensity and soil flooding.

    Science.gov (United States)

    Mielke, Marcelo S; Schaffer, Bruce

    2010-01-01

    The interactive effects of changing light intensity and soil flooding on the photosynthetic performance of Eugenia uniflora L. (Myrtaceae) seedlings in containers were examined. Two hypotheses were tested: (i) the photosynthetic apparatus of shade-adapted leaves can be rapidly acclimated to high light after transfer from shade to full sun, and (ii) photosynthetic acclimation to changing light intensity may be influenced by soil flooding. Seedlings cultivated in a shade house (40% of full sun, approximately 12 mol m(-)(2) day(-)(1)) for 6 months were transferred to full sun (20-40 mol m(-2) day(-1)) or shade (30% of full sun, approximately 8 mol m(-2) day(-1)) and subjected to soil flooding for 23 days or not flooded. Chlorophyll content index (CCI), chlorophyll fluorescence, leaf weight per area (LWA), photosynthetic light-response curves and leaf reflectance indexes were measured during soil flooding and after plants were unflooded. The CCI values increased throughout the experiment in leaves of shaded plants and decreased in leaves of plants transferred to full sun. There were no significant interactions between light intensity and flooding treatments for most of the variables analyzed, with the exception of Fv/Fm 22 days after plants were flooded and 5 days after flooded plants were unflooded. The light environment significantly affected LWA, and light environment and soil flooding significantly affected the light-saturated gross CO(2) assimilation rate expressed on area and dry weight bases (A(max-area) and A(max-wt), respectively), stomatal conductance of water vapor (g(ssat)) and intrinsic water use efficiency (A/g(s)). Five days after flooded plants were unflooded, the normalized difference vegetation index (NDVI) and the scaled photochemical reflectance index (sPRI) were significantly higher in shade than in sun leaves. Thirty days after transferring plants from the shade house to the light treatment, LWA was 30% higher in sun than in shade leaves, and A

  16. Enhanced photocatalytic activity and characterization of magnetic Ag/BiOI/ZnFe2O4 composites for Hg0 removal under fluorescent light irradiation

    Science.gov (United States)

    Li, Chengwei; Zhang, Anchao; Zhang, Lixiang; Song, Jun; Su, Sheng; Sun, Zhijun; Xiang, Jun

    2018-03-01

    A series of magnetic Ag/BiOI/ZnFe2O4 hybrids synthesized via hydrothermal process, subsequent deposition-precipitation and photoreduction method were employed to remove elemental mercury (Hg0) under fluorescent light irradiation. The effects of Ag content, fluorescent light irradiation, reaction temperature, pH value, flue gas composition, anions and photocatalyst dosage on Hg0 removal were investigated in detail. The as-synthesized photocatalysts were characterized using N2 adsorption-desorption, XRD, SEM, TEM, HRTEM, XPS, VSM, DRS, ESR, PL and photocurrent response. The results showed that the ternary Ag/BiOI/ZnFe2O4 hybrids possessed enhanced visible-light-responsive photocatalytic performances for Hg0 removal. Ag/BiOI/ZnFe2O4 photocatalyst could be easily recovered from the reaction solution by an extra magnet and was stable in the process of Hg0 removal. Lower content of Ag was highly dispersed on the surface of BiOI/ZnFe2O4, while higher content of Ag would result in some aggregations and/or the blockages of micropore. In comparison to BiOI/ZnFe2O4, Ag deposited BiOI/ZnFe2O4 material showed lower recombination rate of electron-hole pairs. The superior Hg0 oxidation removal could correspond to good match of BiOI and ZnFe2O4, excellent fluidity and surface plasmon resonance effect of Ag0 nanoparticles, which led to higher separation efficiency of photogenerated electrons and holes, thereby enhancing the hybrids' photocatalytic activity.

  17. Light

    CERN Document Server

    Ditchburn, R W

    1963-01-01

    This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o

  18. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders.

    Science.gov (United States)

    Kaminsky, Natalie; Bihari, Ofer; Kanner, Sivan; Barzilai, Ari

    2016-06-01

    The DNA damage response (DDR) is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes). Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a "hostile" environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit. Copyright © 2016 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

  19. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders

    Directory of Open Access Journals (Sweden)

    Natalie Kaminsky

    2016-06-01

    Full Text Available The DNA damage response (DDR is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes. Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a “hostile” environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.

  20. Seeing the light: the effects of particles, dissolved materials, and temperature on in situ measurements of DOM fluorescence in rivers and streams

    Science.gov (United States)

    Downing, Bryan D.; Pellerin, Brian A.; Bergamaschi, Brian A.; Saraceno, John Franco; Kraus, Tamara E.C.

    2012-01-01

    Field-deployable sensors designed to continuously measure the fluorescence of colored dissolved organic matter (FDOM) in situ are of growing interest. However, the ability to make FDOM measurements that are comparable across sites and over time requires a clear understanding of how instrument characteristics and environmental conditions affect the measurements. In particular, the effects of water temperature and light attenuation by both colored dissolved material and suspended particles may be significant in settings such as rivers and streams. Using natural standard reference materials, we characterized the performance of four commercially-available FDOM sensors under controlled laboratory conditions over ranges of temperature, dissolved organic matter (DOM) concentrations, and turbidity that spanned typical environmental ranges. We also examined field data from several major rivers to assess how often attenuation artifacts or temperature effects might be important. We found that raw (uncorrected) FDOM values were strongly affected by the light attenuation that results from dissolved substances and suspended particles as well as by water temperature. Observed effects of light attenuation and temperature agreed well with theory. Our results show that correction of measured FDOM values to account for these effects is necessary and feasible over much of the range of temperature, DOM concentration, and turbidity commonly encountered in surface waters. In most cases, collecting high-quality FDOM measurements that are comparable through time and between sites will require concurrent measurements of temperature and turbidity, and periodic discrete sample collection for laboratory measurement of DOM.

  1. Malfunction Rates of Bird Flight Diverters on Powerlines in the Mongolian Gobi

    Directory of Open Access Journals (Sweden)

    Batsuuri Dashnyam

    2016-11-01

    Full Text Available The Oyu Tolgoi (OT project, one of the world’s largest copper and gold mines, is located in Gobi Desert of Mongolia. To help meet its target of Net Positive Impact on key biodiversity features such as the Houbara bustard (Chlamydotis undulata the OT installed bird fl ight diverters (BFDs include spiral and fl apper devices to its power transmission lines to reduce the risk of birds hitting the wires. Despite the many studies demonstrating that BFDs reduce collision rates, we could fi nd no published information on malfunction rates of BFDs. In January 2013, we surveyed the physical function of 1,200 BFDs (e.g. 600 fl appers and 600 spirals in three sample areas on each of four lines of varying voltage and structure. Of the 600 fl appers examined, 123 had malfunctioned within nine months of installation, while the malfunction rate of the 600 spirals studied was zero. Using a Generalized Linear Mixed Model, we found that the rate of fl apper malfunction increased with decreasing fl apper size and power line diameter. Further, the fl apper malfunction rate increased as the distance between poles increased. The cost of replacing malfunctioning BFDs is very high as there are serious health and safety constraints related to working with live wires. Factors aff ecting diverter malfunctioning need to be considered for future powerline projects and our information can serve as basis for developing national standards or regulations for powerline mitigation in Mongolia.

  2. Efficient fluorescence/phosphorescence white organic light-emitting diodes with ultra high color stability and mild efficiency roll-off

    Science.gov (United States)

    Du, Xiaoyang; Tao, Silu; Huang, Yun; Yang, Xiaoxia; Ding, Xulin; Zhang, Xiaohong

    2015-11-01

    Efficient fluorescence/phosphorescence hybrid white organic light-emitting diodes (OLEDs) with single doped co-host structure have been fabricated. Device using 9-Naphthyl-10 -(4-triphenylamine)anthrancene as the fluorescent dopant and Ir(ppy)3 and Ir(2-phq)3 as the green and orange phosphorescent dopants show the luminous efficiency of 12.4% (17.6 lm/W, 27.5 cd/A) at 1000 cd/m2. Most important to note that the efficiency-brightness roll-off of the device was very mild. With the brightness rising up to 5000 and 10 000 cd/m2, the efficiency could be kept at 11.8% (14.0 lm/W, 26.5 cd/A) and 11.0% (11.8 lm/W, 25.0 cd/A). The Commission Internationale de L'Eclairage (CIE) coordinates and color rending index (CRI) were measured to be (0.45, 0.48) and 65, respectively, and remained the same in a large range of brightness (1000-10 000 cd/m2), which is scarce in the reported white OLEDs. The performance of the device at high luminance (5000 and 10 000 cd/m2) was among the best reported results including fluorescence/phosphorescence hybrid and all-phosphorescent white OLEDs. Moreover, the CRI of the white OLED can be improved to 83 by using a yellow-green emitter (Ir(ppy)2bop) in the device.

  3. 40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

  4. 40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

  5. Novel lanthanide pH fluorescent probes based on multiple emissions and its visible-light-sensitized feature

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jintai [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Zheng, Yuhui, E-mail: yhzheng78@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Wang, Qianming, E-mail: qmwang@scnu.edu.cn [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Guangzhou 510006 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Zeng, Zhi [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Zhang, Cheng Cheng [Departments of Physiology and Developmental Biology, University of Texas Southwestern Medical Center, Dallas (United States)

    2014-08-11

    Graphical abstract: A new type of Eu(III) ofloxacin complex as the fluorescent pH indicator has been reported. Compared to pure ligand, the complex offers more distinguished color changes (green–red–blue) derived from both lanthanide line emissions and the secondary ionization steps of ofloxacin. - Highlights: • The pH probe offers a very wide working range in water (pH 1–14). • The emission changes have multiple colors. • Long-lived excited state lifetimes of Eu(III) has been used. • Two types of pH sensitive hydrogels were fabricated. - Abstract: A new type of Eu(III) ofloxacin complex as the fluorescent pH indicator has been presented. Compared to pure ligand, the complex offers more distinguished color changes (green–red–blue) derived from both lanthanide line emissions and the secondary ionization steps of ofloxacin. During the concentration dependence experiments, the photoluminescence studies on the complex showed that the excitation of this pH probe can occur at a very long wavelength which extends to visible range (Ex = 427 nm). Furthermore, the functional complex was successfully incorporated into soft networks and two novel luminescent hydrogels (rod and film) were fabricated. The soft materials also exhibited specific responses towards the pH variation. Finally, the onion cell-stain experiments were carried out to further confirm the validity of pH dependence and the results support the idea that the material will be suitable for monitoring biological samples in the future.

  6. Time-lapse 3-D measurements of a glucose biosensor in multicellular spheroids by light sheet fluorescence microscopy in commercial 96-well plates.

    Science.gov (United States)

    Maioli, Vincent; Chennell, George; Sparks, Hugh; Lana, Tobia; Kumar, Sunil; Carling, David; Sardini, Alessandro; Dunsby, Chris

    2016-11-25

    Light sheet fluorescence microscopy has previously been demonstrated on a commercially available inverted fluorescence microscope frame using the method of oblique plane microscopy (OPM). In this paper, OPM is adapted to allow time-lapse 3-D imaging of 3-D biological cultures in commercially available glass-bottomed 96-well plates using a stage-scanning OPM approach (ssOPM). Time-lapse 3-D imaging of multicellular spheroids expressing a glucose Förster resonance energy transfer (FRET) biosensor is demonstrated in 16 fields of view with image acquisition at 10 minute intervals. As a proof-of-principle, the ssOPM system is also used to acquire a dose response curve with the concentration of glucose in the culture medium being varied across 42 wells of a 96-well plate with the whole acquisition taking 9 min. The 3-D image data enable the FRET ratio to be measured as a function of distance from the surface of the spheroid. Overall, the results demonstrate the capability of the OPM system to measure spatio-temporal changes in FRET ratio in 3-D in multicellular spheroids over time in a multi-well plate format.

  7. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

    Science.gov (United States)

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2016-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy.

  8. Application of quantitative light-induced fluorescence to determine the depth of demineralization of dental fluorosis in enamel microabrasion: a case report

    Directory of Open Access Journals (Sweden)

    Tae-Young Park

    2016-08-01

    Full Text Available Enamel microabrasion has become accepted as a conservative, nonrestorative method of removing intrinsic and superficial dysmineralization defects from dental fluorosis, restoring esthetics with minimal loss of enamel. However, it can be difficult to determine if restoration is necessary in dental fluorosis, because the lesion depth is often not easily recognized. This case report presents a method for analysis of enamel hypoplasia that uses quantitative light-induced fluorescence (QLF followed by a combination of enamel microabrasion with carbamide peroxide home bleaching. We describe the utility of QLF when selecting a conservative treatment plan and confirming treatment efficacy. In this case, the treatment plan was based on QLF analysis, and the selected combination treatment of microabrasion and bleaching had good results.

  9. Development of an x-ray fluorescence microprobe at the National Synchrotron Light Source, Brookhaven National Laboratory: Early results: Comparison with data from other techniques

    International Nuclear Information System (INIS)

    Smith, J.V.; Rivers, M.L.; Sutton, S.R.; Jones, K.W.; Hanson, A.L.; Gordon, B.M.

    1986-01-01

    Theoretical predictions for the detection levels in x-ray fluorescence analysis with a synchrotron storage ring are being achieved experimentally at several laboratories. This paper is deliberately restricted to the state of development of the Brookhaven National Laboratory/University of Chicago instruments. Analyses at the parts per million (ppM) level are being made using white light apertured to 20 μm and an energy dispersive system. This system is particularly useful for elements with Z > 20 in materials dominated by elements with Z < 20. Diffraction causes an interference for crystalline materials. Development of a focusing microprobe for tunable monochromatic x-rays and a wavelength dispersive spectrometer (WDS) is delayed by problems in shaping an 8:1 focusing mirror to the required accuracy. Reconnaissance analyses with a wiggler source on the CHESS synchrotron have been made in the K spectrum up to Z = 80

  10. ultraLM and miniLM: Locator tools for smart tracking of fluorescent cells in correlative light and electron microscopy [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Elisabeth Brama

    2016-12-01

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

  11. An expert system for sensor data validation and malfunction detection

    International Nuclear Information System (INIS)

    Hashemi, S.; Hajek, B.K.; Miller, D.W.

    1987-01-01

    Nuclear power plant operation and monitoring in general is a complex task which requires a large number of sensors, alarms and displays. At any instant in time, the operator is required to make a judgment about the state of the plant and to react accordingly. During abnormal situations, operators are further burdened with time constraints. The possibility of an undetected faulty instrumentation line, adds to the complexity of operators' reasoning tasks. Failure of human operators to cope with the conceptual complexity of abnormal situations often leads to more serious malfunctions and further damages to plant (TMI-2 as an example). During these abnormalities, operators rely on the information provided by the plant sensors and associated alarms. Their usefulness however, is quickly diminished by their large number and the extremely difficult task of interpreting and comprehending the information provided by them. The need for an aid to assist the operator in interpreting the available data and diagnosis of problems is obvious. Recent work at the Ohio State University Laboratory of Artificial Intelligence Research (LAIR) and the nuclear engineering program has concentrated on the problem of diagnostic expert systems performance and their applicability to the nuclear power plant domain. There has also been concern about the diagnostic expert systems performance when using potentially invalid sensor data. Because of this research, an expert system has been developed that can perform diagnostic problem solving despite the existence of some conflicting data in the domain. This work has resulted in enhancement of a programming tool, that allows domain experts to create a diagnostic system that will be to some degree, tolerant of bad data while performing diagnosis. This expert system is described here

  12. Nearly 100% triplet harvesting in conventional fluorescent dopant-based organic light-emitting devices through energy transfer from exciplex.

    Science.gov (United States)

    Liu, Xiao-Ke; Chen, Zhan; Zheng, Cai-Jun; Chen, Miao; Liu, Wei; Zhang, Xiao-Hong; Lee, Chun-Sing

    2015-03-25

    Nearly 100% triplet harvesting in conventional fluorophor-based organic light-emitting devices is realized through energy transfer from exciplex. The best C545T-doped device using the exciplex host exhibits a maximum current efficiency of 44.0 cd A(-1) , a maximum power efficiency of 46.1 lm W(-1) , and a maximum external quantum efficiency of 14.5%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 40 CFR 1045.110 - How must my engines diagnose malfunctions?

    Science.gov (United States)

    2010-07-01

    ... color except red. Visible malfunction indicators must display “Check Engine,” “Service Engine Soon,” or... engine operation. (d) Store trouble codes in computer memory. Record and store in computer memory any...

  14. Bactericidal Activity of Aqueous Acrylic Paint Dispersion for Wooden Substrates Based on TiO2 Nanoparticles Activated by Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Diana Di Gioia

    2013-08-01

    Full Text Available The photocatalytic effect of TiO2 has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO2, while visible light has been used only in a few applications. In these studies, high concentrations of TiO2, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing low TiO2 content (2 vol % for the inactivation of microorganisms involved in hospital-acquired infections. The nanoparticles and the coating have been characterized using spectroscopic techniques and transmission electron microscopy, showing their homogenous dispersion in the acrylic urethane coating. A common fluorescent light source was used to activate the photocatalytic activity of TiO2. The paint dispersion showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The coating containing the TiO2 nanoparticles maintained good UV stability, strong adhesion to the substrate and high hardness. Therefore, the approach used is feasible for paint formulation aimed at disinfection of healthcare surfaces.

  15. Energy transfer between surface-immobilized light-harvesting chlorophyll a/b complex (LHCII) studied by surface plasmon field-enhanced fluorescence spectroscopy (SPFS).

    Science.gov (United States)

    Lauterbach, Rolf; Liu, Jing; Knoll, Wolfgang; Paulsen, Harald

    2010-11-16

    The major light-harvesting chlorophyll a/b complex (LHCII) of the photosynthetic apparatus in green plants can be viewed as a protein scaffold binding and positioning a large number of pigment molecules that combines rapid and efficient excitation energy transfer with effective protection of its pigments from photobleaching. These properties make LHCII potentially interesting as a light harvester (or a model thereof) in photoelectronic applications. Most of such applications would require the LHCII to be immobilized on a solid surface. In a previous study we showed the immobilization of recombinant LHCII on functionalized gold surfaces via a 6-histidine tag (His tag) in the protein moiety. In this work the occurrence and efficiency of Förster energy transfer between immobilized LHCII on a functionalized surface have been analyzed by surface plasmon field-enhanced fluorescence spectroscopy (SPFS). A near-infrared dye was attached to some but not all of the LHC complexes, serving as an energy acceptor to chlorophylls. Analysis of the energy transfer from chlorophylls to this acceptor dye yielded information about the extent of intercomplex energy transfer between immobilized LHCII.

  16. Manipulation of Thermally Activated Delayed Fluorescence of Blue Exciplex Emission: Fully Utilizing Exciton Energy for Highly Efficient Organic Light Emitting Diodes with Low Roll-Off.

    Science.gov (United States)

    Wang, Zixing; Wang, Hedan; Zhu, Jun; Wu, Peng; Shen, Bowen; Dou, Dehai; Wei, Bin

    2017-06-28

    The application of exciplex energy has become a unique way to achieve organic light-emitting diodes (OLEDs) with high efficiencies, low turn-on voltage, and low roll-off. Novel δ-carboline derivatives with high triplet energy (T 1 ≈ 2.92 eV) and high glass transition temperature (T g ≈ 153 °C) were employed to manipulate exciplex emissions in this paper. Deep blue (peak at 436 nm) and pure blue (peak at 468 nm) thermally activated delayed fluorescence (TADF) of exciplex OLEDs were demonstrated by utilizing them as emitters with the maximum current efficiency (CE) of 4.64 cd A -1 , power efficiency (PE) of 2.91 lm W -1 , and external quantum efficiency (EQE) of 2.36%. Highly efficient blue phosphorescent OLEDs doped with FIrpic showed a maximum CE of 55.6 cd A -1 , PE of 52.9 lm W -1 , and EQE of 24.6% respectively with very low turn on voltage at 2.7 V. The devices still remain high CE of 46.5 cd A -1 at 100 cd m -2 , 45.4 cd A -1 at 1000 cd m -2 and 42.3 cd A -1 at 5000 cd m -2 with EQE close to 20% indicating low roll-off. Manipulating blue exciplex emissions by chemical structure gives an ideal strategy to fully utilize all exciton energies for lighting of OLEDs.

  17. On the malfunction of disk-type induction relay under seismic condition

    International Nuclear Information System (INIS)

    Fujita, T.; Shibata, H.; Koizumi, T.

    1985-01-01

    This paper deals with the malfunction of disk-type induction relay. Equations of motion for rotational movement of induction relay was formulated and the dynamic behavior was simulated under various kind of exciting conditions. Experimental verification was also performed using two dimensional shaker table for some actual relays. Sufficient agreement was recognized between experimental and analytical results and consequently the most critical reason to cause the malfunction was pointed out. (orig.)

  18. Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

    Science.gov (United States)

    Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

    2015-07-17

    The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%). Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Trust and automation: the influence of automation malfunctions and system feedback on operator trust

    International Nuclear Information System (INIS)

    Strand, Stine

    2001-10-01

    Level of operator trust in an automatic system, which is not in accordance with the reliability of the system, might impose serious threats concerning issues of safety, productivity and the well being of the operator. Operator trust is therefore regarded as an important variable in man-machine interaction. The focus of this study was the influence of automatic malfunctions and amount of feedback provided by the automatic system on level of operator trust. The study was conducted in conjunction with the Human Centred Automation 2000-experiment. Two questionnaires attempting to measure operator trust were developed, designed to reflect the dimensions of predictability, dependability and faith. Analysis of the questionnaires demonstrated that they were reliable tools for measurement of operator trust. Factor analysis did not completely confirm the theoretical dimensions of trust, but indicated partial support. Operator trust correlated negatively with workload across situations, and positively with performance in complex situations. The results of the hypotheses tests demonstrated that operator trust gradually decreased after introduction of malfunctions. The effect of different malfunctions was however the opposite of what was expected, with obvious malfunctions reducing trust more than more camouflaged and safety critical malfunctions. Trust in the automatic system in general was lower than trust in specific malfunctioning components. Different interfaces providing different amount of feedback to the operator did not significantly influence level of operator trust. (Author)

  20. Rate Constants of PSII Photoinhibition and its Repair, and PSII Fluorescence Parameters in Field Plants in Relation to their Growth Light Environments.

    Science.gov (United States)

    Miyata, Kazunori; Ikeda, Hiroshi; Nakaji, Masayoshi; Kanel, Dhana Raj; Terashima, Ichiro

    2015-09-01

    The extent of photoinhibition of PSII is determined by a balance between the rate of photodamage to PSII and that of repair of the damaged PSII. It has already been indicated that the rate constants of photodamage (kpi) and repair (krec) of the leaves differ depending on their growth light environment. However, there are no studies using plants in the field. We examined these rate constants and fluorescence parameters of several field-grown plants to determine inter-relationships between these values and the growth environment. The kpi values were strongly related to the excess energy, EY, of the puddle model and non-regulated energy dissipation, Y(NO), of the lake model, both multiplied by the photosynthetically active photon flux density (PPFD) level during the photoinhibitory treatment. In contrast, the krec values corrected against in situ air temperature were very strongly related to the daily PPFD level. The plants from the fields showed higher NPQ than the chamber-grown plants, probably because these field plants acclimated to stronger lightflecks than the averaged growth PPFD. Comparing chamber-grown plants and the field plants, we showed that kpi is determined by the incident light level and the photosynthetic capacities such as in situ rate of PSII electron transport and non-photochemical quenching (NPQ) [e.g. Y(NO)×PPFD] and that krec is mostly determined by the growth light and temperature levels. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Distinct roles of the photosystem II protein PsbS and zeaxanthin in the regulation of light harvesting in plants revealed by fluorescence lifetime snapshots.

    Science.gov (United States)

    Sylak-Glassman, Emily J; Malnoë, Alizée; De Re, Eleonora; Brooks, Matthew D; Fischer, Alexandra Lee; Niyogi, Krishna K; Fleming, Graham R

    2014-12-09

    The photosystem II (PSII) protein PsbS and the enzyme violaxanthin deepoxidase (VDE) are known to influence the dynamics of energy-dependent quenching (qE), the component of nonphotochemical quenching (NPQ) that allows plants to respond to fast fluctuations in light intensity. Although the absence of PsbS and VDE has been shown to change the amount of quenching, there have not been any measurements that can detect whether the presence of these proteins alters the type of quenching that occurs. The chlorophyll fluorescence lifetime probes the excited-state chlorophyll relaxation dynamics and can be used to determine the amount of quenching as well as whether two different genotypes with the same amount of NPQ have similar dynamics of excited-state chlorophyll relaxation. We measured the fluorescence lifetimes on whole leaves of Arabidopsis thaliana throughout the induction and relaxation of NPQ for wild type and the qE mutants, npq4, which lacks PsbS; npq1, which lacks VDE and cannot convert violaxanthin to zeaxanthin; and npq1 npq4, which lacks both VDE and PsbS. These measurements show that although PsbS changes the amount of quenching and the rate at which quenching turns on, it does not affect the relaxation dynamics of excited chlorophyll during quenching. In addition, the data suggest that PsbS responds not only to ΔpH but also to the Δψ across the thylakoid membrane. In contrast, the presence of VDE, which is necessary for the accumulation of zeaxanthin, affects the excited-state chlorophyll relaxation dynamics.

  2. Enhanced polymer light-emitting diode property using fluorescent conducting polymer-reduced graphene oxide nanocomposite as active emissive layer

    Science.gov (United States)

    Singh, Jyoti Prakash; Saha, Uttam; Jaiswal, Rimpa; Anand, Raghubir Singh; Srivastava, Anurag; Goswami, Thako Hari

    2014-11-01

    The present article reports the polymer light-emitting diode property of the nanocomposite comprising poly 9,9-dioctyl fluorene- alt-bithiophene and reduced graphene oxide used as an emissive layer. Two times repetition of Hummers oxidation and hydrazine hydrate reduction method produce reduced graphene oxide (term as rGO2) with more uniform distribution in size and thickness. In addition, this uniquely synthesized rGO2 induces favorable shift in balance of electron and hole recombination zone toward the center of emissive layer owing to increase in in-plane crystallite size and high localize aromatic confinement. Five times increase in maximum device efficiency (Cd/A) and three times increase in maximum brightness (Cd/m2) are achieved with the LED device using nanocomposite as emissive layer compared to neat polymer. Also, the fabricated device requires relatively low turn-on voltage (4 V) because of low energy barrier between PEDOT work function (-5.0 eV) and HOMO levels of bi-thiophene copolymer -5.67 eV) and nanocomposite (-5.66 eV).

  3. Effects of electron transport material on blue organ light-emitting diode with fluorescent dopant of BCzVBi.

    Science.gov (United States)

    Meng, Mei; Song, Wook; Kim, You-Hyun; Lee, Sang-Youn; Jhun, Chul-Gyu; Zhu, Fu Rong; Ryu, Dae Hyun; Kim, Woo-Young

    2013-01-01

    High efficiency blue organic light emitting diodes (OLEDs), based on 2-me-thyl-9,10-di(2-naphthyl) anthracene (MADN) doped with 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi), were fabricated using two different electron transport layers (ETLs) of tris(8-hydroxyquinolino)-aluminum (Alq3) and 4,7-di-phenyl-1,10-phenanthroline (Bphen). Bphen ETL layers favored the efficient hole-electron recombination in the emissive layer of the BCzVBi-doped blue OLEDs, leading to high luminous efficiency and quantum efficiency of 8.34 cd/A at 100 mA/cm2 and 5.73% at 100 cd/m2, respectively. Maximum luminance of blue OLED with Bphen ETL and Alq3 ETL were 10670 cd/m2, and CIExy coordinates of blue OLEDs were (0.180, 0279) and (0.155, 0.212) at 100 cd/m2.

  4. PS II model based analysis of transient fluorescence yield measured on whole leaves of Arabidopsis thaliana after excitation with light flashes of different energies.

    Science.gov (United States)

    Belyaeva, N E; Schmitt, F-J; Paschenko, V Z; Riznichenko, G Yu; Rubin, A B; Renger, G

    2011-02-01

    Our recently presented PS II model (Belyaeva et al., 2008) was improved in order to permit a consistent simulation of Single Flash Induced Transient Fluorescence Yield (SFITFY) traces that were earlier measured by Steffen et al. (2005) on whole leaves of Arabidopsis (A.) thaliana at four different energies of the actinic flash. As the essential modification, the shape of the actinic flash was explicitly taken into account assuming that an exponentially decaying rate simulates the time dependent excitation of PS II by the 10 ns actinic flash. The maximum amplitude of this excitation exceeds that of the measuring light by 9 orders of magnitude. A very good fit of the SFITFY data was achieved in the time domain from 100 ns to 10s for all actinic flash energies (the maximum energy of 7.5 × 10¹⁶ photons/(cm²flash) is set to 100%, the relative energies of weaker actinic flashes were of ∼8%, 4%, ∼1%). Our model allows the calculation and visualization of the transient PS II redox state populations ranging from the dark adapted state, via excitation energy and electron transfer steps induced by pulse excitation, followed by final relaxation into the stationary state eventually attained under the measuring light. It turned out that the rate constants of electron transfer steps are invariant to intensity of the actinic laser flash. In marked contrast, an increase of the actinic flash energy by more than two orders of magnitude from 5.4×10¹⁴ photons/(cm²flash) to 7.5×10¹⁶ photons/(cm²flash), leads to an increase of the extent of fluorescence quenching due to carotenoid triplet (³Car) formation by a factor of 14 and of the recombination reaction between reduced primary pheophytin (Phe(-)) and P680(+) by a factor of 3 while the heat dissipation in the antenna complex remains virtually constant. The modified PS II model offers new opportunities to compare electron transfer and dissipative parameters for different species (e.g. for the green algae and the

  5. Hybrid white organic light-emitting diodes combining blue-fluorescent polymer and red phosphorescent Pt(II) complexes as active layer

    Energy Technology Data Exchange (ETDEWEB)

    Germino, Jose Carlos; Faleiros, Marcelo Meira; Moraes, Emmanuel Santos; Atvars, Teresa Dib Zambon, E-mail: kakagermino@hotmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Domingues, Raquel Aparecida [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil); Quites, Fernando Junior [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil); Freitas, Jilian Nei de [Centro de Tecnologia da Informacao Renato Archer, Campinas, SP (Brazil)

    2016-07-01

    Full text: In this work we proposed a PFO composite with two salicylidene based Pt(II) coordination compounds, the [Pt(salophen)] and [Pt(sal-3,4-ben)] (red emitters), as emissive layer (EML) for Organic Light-emitting Diodes (OLEDs), combining a blue-fluorescent polymer (PFO) with red-phosphorescent Pt(II) coordination complexes in order to obtain an efficient white electroluminescent EML for WOLEDs application. Firstly, [Pt(salophen)] and [Pt(sal-3,4-ben)] were synthesized, purified and characterized by single crystal X-ray diffraction, yielding their respective expected molecular structures. The photoluminescence properties of the devices were evaluated by steady-state (electronic absorption and emission spectroscopies) and transient (fluorescence decays and TRES) measurements. It was observed the presence of non-radiative energy transfer processes between the PFO derivative and Pt(II) complexes. Posteriorly, the Pt(II) complexes were blended with PVK at 1% mol:mol ratio and OLEDs were made, leading to red-emitting devices with high color purity for the two coordination compounds. However, the two devices present low current efficiency values. In order to improve the electroluminescence properties of Pt(II) complexes PhOLEDs, PVK host was substituted by PFO at 0.5, 1.0 and 2.5% mol:mol ratios of complex and it was observed a great improvement of their optical-electronic properties in terms of luminance, voltage, current density and current efficiency in comparison to PVK composites or pure PFO devices. At 2.5% concentration, predominant bands of Pt(II) complexes were observed at low and high voltages. For the other concentrations, a different behavior was observed: the emission bands and device color were function of applied electrical field, exhibiting a red color at lower voltages (5 to 9V) and the PFO characteristic emission between 9 and 13V, leading to a white light emission at 13V. The best results were obtained for [Pt(sal-3,4-ben)] coordination compound

  6. Species-specific and seasonal differences in chlorophyll fluorescence and photosynthetic light response among three evergreen species in a Madrean sky island mixed conifer forest

    Science.gov (United States)

    Potts, D. L.; Minor, R. L.; Braun, Z.; Barron-Gafford, G. A.

    2012-12-01

    Unlike the snowmelt-dominated hydroclimate of more northern mountainous regions, the hydroclimate of the Madrean sky islands is characterized by snowmelt and convective storms associated with the North American Monsoon. These mid-summer storms trigger biological activity and are important drivers of primary productivity. For example, at the highest elevations where mixed conifer forests occur, ecosystem carbon balance is influenced by monsoon rains. Whereas these storms' significance is increasingly recognized at the ecosystem scale, species-specific physiological responses to the monsoon are poorly known. Prior to and following monsoon onset, we measured pre-dawn and light-adapted chlorophyll fluorescence as well as photosynthetic light response in southwestern white pine (Pinus strobiformis), ponderosa pine (Pinus ponderosa), and Douglas fir (Pseudotsuga menziesii) in a Madrean sky island mixed conifer forest near Tucson, Arizona. Photochemical quenching (qp), an indicator of the proportion of open PSII reaction centers, was greatest in P. strobiformis and least in P. menziesii and increased in response to monsoon rains (repeated-measures ANOVA; species, F2,14 = 6.17, P = 0.012; time, F2,14= 8.17, P = 0.013). In contrast, non-photochemical quenching (qN), an indicator of heat dissipation ability, was greatest in P. ponderosa and least in P. menziesii, but was not influenced by monsoon onset (repeated-measures ANOVA; species, F2,12 = 4.18, P = 0.042). Estimated from leaf area-adjusted photosynthetic light response curves, maximum photosynthetic rate (Amax) was greatest in P. ponderosa and least in P. menziesii (repeated-measures ANOVA; species, F2,8= 40.8, P = 0.001). Surprisingly, while the monsoon positively influenced Amax among P. ponderosa and P. strobiformis, Amax of P. menziesii declined with monsoon onset (repeated-measures ANOVA; species x time, F2,8 = 13.8, P = 0.002). Calculated as the initial slope of the photosynthetic light response curve, light

  7. N-doped TiO2 photo-catalyst for the degradation of 1,2-dichloroethane under fluorescent light

    International Nuclear Information System (INIS)

    Lin, Yi-Hsing; Chiu, Tang-Chun; Hsueh, Hsin-Ta; Chu, Hsin

    2011-01-01

    The photo-catalytic degradation of 1,2-dichloroethane (1, 2-DCE) using nitrogen-doped TiO 2 photo-catalysts under fluorescent light irradiation was investigated. Highly pure TiO 2 and nitrogen-doped TiO 2 were prepared by a sol-gel method and characterized by thermo-gravimetric/differential-thermal analysis (TG/DTA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The results indicate that the photo-catalysts were mainly nano-size with an anatase-phase structure. The degradation reaction of 1,2-DCE was operated under visible-light irradiation, and the photo-catalytic oxidation was conducted in a batch photo-reactor with various nitrogen doping ratios (N/Ti = 0-25 mol%). The relative humidity (RH) was controlled at 0-20% and the oxygen concentration was controlled at 0-21%. The photo-degradation with nitrogen-doped TiO 2 showed superior photo-catalytic activity compared to that for pure TiO 2 . TiO 2 doped with 15 mol% nitrogen exhibited the best photo-catalytic efficiency under the tested conditions. The products from the 1,2-DCE photo-catalytic oxidation were CO 2 and water; the by-products included dichloromethane, methyl chloride, ethyl chloride, carbon monoxide, and hydrogen chloride. The reaction pathway of 1,2-DCE indicates that oxygen molecules are the major factor that causes the degradation of 1,2-DCE in the gas phase.

  8. Labelling of living mammalian spermatozoa with the fluorescent thiol alkylating agent, monobromobimane (MB): immobilization upon exposure to ultraviolet light and analysis of acrosomal status

    International Nuclear Information System (INIS)

    Cummins, J.M.; Fleming, A.D.; Crozet, N.; Kuehl, T.J.; Kosower, N.S.; Yanagimachi, R.

    1986-01-01

    Living spermatozoa of seven mammalian species were treated with the thiol-alkylating fluorescent labelling compound, monobromobimane (MBBR). MB-labelling alone had no effect on sperm motility, nor on the time course or ability of golden hamster spermatozoa to undergo the acrosome reaction when capacitated in vitro. Exposure of MB-labelled spermatozoa to ultraviolet (UV) light and excitation of the MB fluorochrome resulted in virtually immediate immobilization of the spermatozoa without affecting acrosomal status. UV exposure of unlabelled spermatozoa for up to 30 sec had no effect upon motility. Immobilization of MB-labelled spermatozoa depended on the midpiece being irradiated, as irradiation of the head alone, or of the more distal parts of the principal piece, had little or no effect upon motility. Labelling with MB followed by immobilization of individually selected spermatozoa was most useful for detailing the course and site of occurrence of the acrosome reaction during penetration of the cumulus oophorus by golden hamster spermatozoa in vitro. In these often hyperactivated spermatozoa, precise determination of the acrosomal status could not often otherwise be made due to the difficulty in visualizing the acrosomal region of a vigorously thrashing, hyperactivated spermatozoon. This technique should prove valuable in a variety of studies on sperm motility, capacitation and fertilization, and could also be extended to other cell systems

  9. Hybrid white organic light-emitting devices consisting of a non-doped thermally activated delayed fluorescent emitter and an ultrathin phosphorescent emitter

    International Nuclear Information System (INIS)

    Zhao, Juan; Wang, Zijun; Wang, Run; Chi, Zhenguo; Yu, Junsheng

    2017-01-01

    Hybrid white organic light-emitting devices (OLEDs) are fabricated by employing non-doped emitting layers (EMLs), which are consisted of a blue thermally activated delayed fluorescent (TADF) emitter 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin yellow iridium complex bis[2-(4-tertbutylphenyl)benzothiazolato-N,C 2′ ] iridium (acetylacetonate) [(tbt) 2 Ir(acac)]. With thickness optimization of DMAC-DPS, a white OLED achieves maximum current efficiency, power efficiency and external quantum efficiency of 34.9 cd/A, 29.2 lm/W and 11.4%, respectively, as well as warm white emission with relatively stable electroluminescence spectra. The results suggest that, bipolar charge carrier transport property and concentration independent property of DMAC-DPS, charge carrier trapping effect of the ultrathin (tbt) 2 Ir(acac), and balanced self-emission process and energy transfer process between DMAC-DPS and (tbt) 2 Ir(acac), contribute to high device performance.

  10. Hybrid white organic light-emitting devices consisting of a non-doped thermally activated delayed fluorescent emitter and an ultrathin phosphorescent emitter

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Juan [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); School of Chemistry, Sun Yat-sen University, Guangzhou 510275 (China); Wang, Zijun; Wang, Run [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Chi, Zhenguo, E-mail: chizhg@mail.sysu.edu.cn [School of Chemistry, Sun Yat-sen University, Guangzhou 510275 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2017-04-15

    Hybrid white organic light-emitting devices (OLEDs) are fabricated by employing non-doped emitting layers (EMLs), which are consisted of a blue thermally activated delayed fluorescent (TADF) emitter 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin yellow iridium complex bis[2-(4-tertbutylphenyl)benzothiazolato-N,C{sup 2′}] iridium (acetylacetonate) [(tbt){sub 2}Ir(acac)]. With thickness optimization of DMAC-DPS, a white OLED achieves maximum current efficiency, power efficiency and external quantum efficiency of 34.9 cd/A, 29.2 lm/W and 11.4%, respectively, as well as warm white emission with relatively stable electroluminescence spectra. The results suggest that, bipolar charge carrier transport property and concentration independent property of DMAC-DPS, charge carrier trapping effect of the ultrathin (tbt){sub 2}Ir(acac), and balanced self-emission process and energy transfer process between DMAC-DPS and (tbt){sub 2}Ir(acac), contribute to high device performance.

  11. Effect of an oral health education program based on the use of quantitative light-induced fluorescence technology in Uzbekistan adolescents.

    Science.gov (United States)

    Khudanov, Bakhtinur; Jung, Hoi In; Kahharova, Dono; Lee, Jeong-Woo; Hamidov, Ilhom; Lee, Eun-Song; Kim, Baek-Il

    2018-03-01

    The aim of this study was to determine whether an oral health education program using a Qscan device based on quantitative light-induced fluorescence (QLF) technology could improve the oral hygiene status and oral health literacy of adolescents. One hundred adolescents aged 14-16 years attending a school in Tashkent city were included in this study. The participants were assigned to the following two groups using permuted block randomization technique: (i) control group (traditional learning) and (ii) experimental group (Qscan device-based learning). The participants included in the experimental group received additional education and training on dental plaque removal using the Qscan device. The accumulated levels of plaque were assessed in all participants, who also completed questionnaires about their oral health status, oral health knowledge, attitude, and behavior during an 8-week period. There were statistically significant improvements in the experimental group compared to the control group in the plaque index (0.46 vs 0.07, p education program based on the use of QLF technology could be useful for improving the oral hygiene status and oral health literacy of adolescents in Uzbekistan. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Treating malfunction filtering bleb with repeated needling combined with adjunctive 5-FU after glaucoma filtration surgery

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2013-07-01

    Full Text Available AIM: To evaluate the therapeutic efficacy of a repeated bleb needling technique combined with subconjunctival injection of 5-FU in eyes with previous glaucoma surgery that had malfunctional filtering blebs. METHODS: A retrospective review of 34 consecutive patients(34 eyesof repeated bleb needling combined with subconjunctival injection of 5-FU in eyes, which had malfunctional filtering blebs after previous glaucoma surgery in our hospital from March 2009 to February 2013 was performed. The intraocular pressures(IOP, shapes of filtering blebs and complications after surgery were analyzed. RESULTS: There was significant reduction of mean IOP from 35.51mmHg to 14.43mmHg(PCONCLUSION: Repeated needling with adjunctive 5-FU proved a highly effective, safe alternative to treat malfunctional filtering blebs after previous glaucoma surgery.

  13. Comparison of the rate constants for energy transfer in the light-harvesting protein, C-phycocyanin, calculated from Foerster`s theory and experimentally measured by time-resolved fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Debreczeny, Martin Paul [Univ. of California, Berkeley, CA (United States)

    1994-05-01

    We have measured and assigned rate constants for energy transfer between chromophores in the light-harvesting protein C-phycocyanin (PC), in the monomeric and trimeric aggregation states, isolated from Synechococcus sp. PCC 7002. In order to compare the measured rate constants with those predicted by Fdrster`s theory of inductive resonance in the weak coupling limit, we have experimentally resolved several properties of the three chromophore types ({beta}{sub 155} {alpha}{sub 84}, {beta}{sub 84}) found in PC monomers, including absorption and fluorescence spectra, extinction coefficients, fluorescence quantum yields, and fluorescence lifetimes. The cpcB/C155S mutant, whose PC is missing the {beta}{sub 155} chromophore, was, useful in effecting the resolution of the chromophore properties and in assigning the experimentally observed rate constants for energy transfer to specific pathways.

  14. Frequency of pacemaker malfunction associated with monopolar electrosurgery during pulse generator replacement or upgrade surgery.

    Science.gov (United States)

    Lin, Yun; Melby, Daniel P; Krishnan, Balaji; Adabag, Selcuk; Tholakanahalli, Venkatakrishna; Li, Jian-Ming

    2017-08-01

    The aim of this study is to investigate the frequency of electrosurgery-related pacemaker malfunction. A retrospective study was conducted to investigate electrosurgery-related pacemaker malfunction in consecutive patients undergoing pulse generator (PG) replacement or upgrade from two large hospitals in Minneapolis, MN between January 2011 and January 2014. The occurrence of this pacemaker malfunction was then studied by using MAUDE database for all four major device vendors. A total of 1398 consecutive patients from 2 large tertiary referral centers in Minneapolis, MN undergoing PG replacement or upgrade surgery were retrospectively studied. Four patients (0.3% of all patients), all with pacemakers from St Jude Medical (2.8%, 4 of 142) had output failure or inappropriately low pacing rate below 30 bpm during electrosurgery, despite being programmed in an asynchronous mode. During the same period, 1174 cases of pacemaker malfunctions were reported on the same models in MAUDE database, 37 of which (3.2%) were electrosurgery-related. Twenty-four cases (65%) had output failure or inappropriate low pacing rate. The distribution of adverse events was loss of pacing (59.5%), reversion to backup pacing (32.4%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The majority of these (78.5%) occurred during PG replacement at ERI or upgrade surgery. No electrosurgery-related malfunction was found in MAUDE database on 862 pacemaker malfunction cases during the same period from other vendors. Electrosurgery during PG replacement or upgrade surgery can trigger output failure or inappropriate low pacing rate in certain models of modern pacemakers. Cautions should be taken for pacemaker-dependent patients.

  15. An experimental study of emission and combustion characteristics of marine diesel engine with fuel pump malfunctions

    International Nuclear Information System (INIS)

    Kowalski, Jerzy

    2014-01-01

    Presented paper shows the results of the laboratory study on the relation between the chosen malfunctions of a fuel pump and the exhaust gas composition of the marine engine. The object of research is a laboratory four-stroke diesel engine, operated at a constant speed. During the research over 50 parameters were measured with technical condition of the engine recognized as “working properly” and with simulated fuel pump malfunctions. Considered malfunctions are: fuel injection timing delay and two sets of fuel leakages in the fuel pump of one engine cylinder. The results of laboratory research confirm that fuel injection timing delay and fuel leakage in the fuel pump cause relatively small changes in thermodynamic parameters of the engine. Changes of absolute values are so small they may be omitted by marine engines operators. The measuring of the exhaust gas composition shows markedly affection with simulated malfunctions of the fuel pump. Engine operation with delayed fuel injection timing in one cylinder indicates CO 2 emission increase and NOx emission decreases. CO emission increases only at high the engine loads. Fuel leakage in the fuel pump causes changes in CO emission, the increase of CO 2 emission and the decrease of NOx emission. - Highlights: •Chosen malfunctions of the fuel injection pump of marine engine are simulated. •Changes of thermodynamic parameters of marine engine are analyzed. •Changes of CO, CO 2 and NOx emission characteristics of marine engine are analyzed. •Injection pump malfunctions take significant changes in emission characteristics

  16. An ecological interface for supporting situation awareness during malfunction and process and automation

    International Nuclear Information System (INIS)

    Ohtsu, Masataka; Furukawa, Hiroshi; Inagaki, Toshiyuki; Monta, Kazuo

    2000-01-01

    This paper describes the outline of an experiment to investigate the effect of an ecological interface for supporting situation awareness during malfunction of process. We developed an ecological interface and an conventional interface for the simulator SCARLETT of a virtual plant that have two process control modes (automatic process control mode and manual process control mode). The purpose of this experiment is to investigate how interface and process control mode have any effects on situation awareness of human operator during malfunction of process, whether there are any interaction between interface and process control mode. We have been conducted this experiment now. (author)

  17. A new light on Alkaptonuria: A Fourier-transform infrared microscopy (FTIRM) and low energy X-ray fluorescence (LEXRF) microscopy correlative study on a rare disease.

    Science.gov (United States)

    Mitri, Elisa; Millucci, Lia; Merolle, Lucia; Bernardini, Giulia; Vaccari, Lisa; Gianoncelli, Alessandra; Santucci, Annalisa

    2017-05-01

    Alkaptonuria (AKU) is an ultra-rare disease associated to the lack of an enzyme involved in tyrosine catabolism. This deficiency results in the accumulation of homogentisic acid (HGA) in the form of ochronotic pigment in joint cartilage, leading to a severe arthropathy. Secondary amyloidosis has been also unequivocally assessed as a comorbidity of AKU arthropathy. Composition of ochronotic pigment and how it is structurally related to amyloid is still unknown. We exploited Synchrotron Radiation Infrared and X-Ray Fluorescence microscopies in combination with conventional bio-assays and analytical tools to characterize chemical composition and morphology of AKU cartilage. We evinced that AKU cartilage is characterized by proteoglycans depletion, increased Sodium levels, accumulation of lipids in the peri-lacunar regions and amyloid formation. We also highlighted an increase of aromatic compounds and oxygen-containing species, depletion in overall Magnesium content (although localized in the peri-lacunar region) and the presence of calcium carbonate fragments in proximity of cartilage lacunae. We highlighted common features between AKU and arthropathy, but also specific signatures of the disease, like presence of amyloids and peculiar calcifications. Our analyses provide a unified picture of AKU cartilage, shedding a new light on the disease and opening new perspectives. Ochronotic pigment is a hallmark of AKU and responsible of tissue degeneration. Conventional bio-assays have not yet clarified its composition and its structural relationship with amyloids. The present work proposes new strategies for filling the aforementioned gap that encompass the integration of new analytical approaches with standardized analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Estimating Diurnal Courses of Gross Primary Production for Maize: A Comparison of Sun-Induced Chlorophyll Fluorescence, Light-Use Efficiency and Process-Based Models

    Directory of Open Access Journals (Sweden)

    Tianxiang Cui

    2017-12-01

    Full Text Available Accurately quantifying gross primary production (GPP is of vital importance to understanding the global carbon cycle. Light-use efficiency (LUE models and process-based models have been widely used to estimate GPP at different spatial and temporal scales. However, large uncertainties remain in quantifying GPP, especially for croplands. Recently, remote measurements of solar-induced chlorophyll fluorescence (SIF have provided a new perspective to assess actual levels of plant photosynthesis. In the presented study, we evaluated the performance of three approaches, including the LUE-based multi-source data synergized quantitative (MuSyQ GPP algorithm, the process-based boreal ecosystem productivity simulator (BEPS model, and the SIF-based statistical model, in estimating the diurnal courses of GPP at a maize site in Zhangye, China. A field campaign was conducted to acquire synchronous far-red SIF (SIF760 observations and flux tower-based GPP measurements. Our results showed that both SIF760 and GPP were linearly correlated with APAR, and the SIF760-GPP relationship was adequately characterized using a linear function. The evaluation of the modeled GPP against the GPP measured from the tower demonstrated that all three approaches provided reasonable estimates, with R2 values of 0.702, 0.867, and 0.667 and RMSE values of 0.247, 0.153, and 0.236 mg m−2 s−1 for the MuSyQ-GPP, BEPS and SIF models, respectively. This study indicated that the BEPS model simulated the GPP best due to its efficiency in describing the underlying physiological processes of sunlit and shaded leaves. The MuSyQ-GPP model was limited by its simplification of some critical ecological processes and its weakness in characterizing the contribution of shaded leaves. The SIF760-based model demonstrated a relatively limited accuracy but showed its potential in modeling GPP without dependency on climate inputs in short-term studies.

  19. Stoke's and anti-Stoke's characteristics of anaerobic and aerobic bacterias at excitation of fluorescence by low-intensity red light: I. Research of anaerobic bacterias

    Science.gov (United States)

    Masychev, Victor I.; Alexandrov, Michail T.

    2000-04-01

    Biopsy or photo dynamic therapy of tumors are usually investigated by fluorescent diagnostics methods. Information on modified method of fluorescence diagnostics of inflammatory diseases is represented in this research. Anaerobic micro organisms are often the cause of these pathological processes. These micro organisms also accompany disbiotic processes in intestines.

  20. Fluorescence and Spectral Imaging

    Directory of Open Access Journals (Sweden)

    Ralph S. DaCosta

    2007-01-01

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

  1. Loss of labor time due to malfunctioning ICTs and ICT skill insufficiencies

    NARCIS (Netherlands)

    van Deursen, Alexander Johannes Aloysius Maria; van Dijk, Johannes A.G.M.

    2014-01-01

    Purpose – The purpose of this paper is to unexplore the area of information and communication technology (ICT) use in organizations related to the assumed productivity gains by the use of ICTs. On the one hand, the paper focus on the losses of labor time that are caused by malfunctioning hardware or

  2. Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

    International Nuclear Information System (INIS)

    Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark

    1997-01-01

    To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis

  3. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Requirements for startups, shutdowns, and malfunctions. 63.310 Section 63.310 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns...

  4. 40 CFR 1048.110 - How must my engines diagnose malfunctions?

    Science.gov (United States)

    2010-07-01

    ... readily visible to the operator; it may be any color except red. When the MIL goes on, it must display..., the MIL may stay off during later engine operation. (d) Store trouble codes in computer memory. Record and store in computer memory any diagnostic trouble codes showing a malfunction that should illuminate...

  5. Using statistical anomaly detection models to find clinical decision support malfunctions.

    Science.gov (United States)

    Ray, Soumi; McEvoy, Dustin S; Aaron, Skye; Hickman, Thu-Trang; Wright, Adam

    2018-05-11

    Malfunctions in Clinical Decision Support (CDS) systems occur due to a multitude of reasons, and often go unnoticed, leading to potentially poor outcomes. Our goal was to identify malfunctions within CDS systems. We evaluated 6 anomaly detection models: (1) Poisson Changepoint Model, (2) Autoregressive Integrated Moving Average (ARIMA) Model, (3) Hierarchical Divisive Changepoint (HDC) Model, (4) Bayesian Changepoint Model, (5) Seasonal Hybrid Extreme Studentized Deviate (SHESD) Model, and (6) E-Divisive with Median (EDM) Model and characterized their ability to find known anomalies. We analyzed 4 CDS alerts with known malfunctions from the Longitudinal Medical Record (LMR) and Epic® (Epic Systems Corporation, Madison, WI, USA) at Brigham and Women's Hospital, Boston, MA. The 4 rules recommend lead testing in children, aspirin therapy in patients with coronary artery disease, pneumococcal vaccination in immunocompromised adults and thyroid testing in patients taking amiodarone. Poisson changepoint, ARIMA, HDC, Bayesian changepoint and the SHESD model were able to detect anomalies in an alert for lead screening in children and in an alert for pneumococcal conjugate vaccine in immunocompromised adults. EDM was able to detect anomalies in an alert for monitoring thyroid function in patients on amiodarone. Malfunctions/anomalies occur frequently in CDS alert systems. It is important to be able to detect such anomalies promptly. Anomaly detection models are useful tools to aid such detections.

  6. Thermo-characterization of power systems components: a tool to diagnose their malfunctions

    International Nuclear Information System (INIS)

    Zaleta-Aguilar, Alejandro; Royo, Javier; Rangel, Victor H.; Torres-Reyes, Ernestina

    2004-01-01

    Concepts on thermodynamic characterization of power system components are presented in this paper. The aim of this work is to evaluate and diagnose the actual operating condition for existing power plant components. What is more, a Reference Performance State (RPS) for power system components which uses the parameters defined as the enthalpy change, ω, the entropy change, σ and the Mass Flow Ratio design, MFR is put forward. Design information and simulation will help to determine the RPS for each component operating without any malfunction. The RPS can be used to compare, to evaluate and to diagnose the actual operating condition of the plant components so as to detect its possible malfunction. A simulated example of a 105 MW power plant is presented herein so that thermo-characterization of steam turbines, a condenser, a heat exchanger, and a pump is illustrated. The induced and intrinsic component malfunction effects on the RPS are also presented. Their effects are related to the RPS, thereby opening the possibility to apply methodologies to any internal decay and/or induced malfunctions that could appear in an operating component, in terms of the heat rate impact

  7. 40 CFR 62.14645 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false What happens during periods of startup... Limits § 62.14645 What happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during periods of CISWI unit startup, shutdown, or...

  8. Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)

    1997-11-01

    To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

  9. 40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

  10. 40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

  11. 40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

  12. 40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

  13. Photocatalytic oxidation removal of Hg{sup 0} using ternary Ag/AgI-Ag{sub 2}CO{sub 3} hybrids in wet scrubbing process under fluorescent light

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Anchao, E-mail: aczhang@qq.com [School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, 454000 (China); Zhang, Lixiang; Chen, Xiaozhuan; Zhu, Qifeng; Liu, Zhichao [School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, 454000 (China); Xiang, Jun, E-mail: xiangjun@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2017-01-15

    Highlights: • Ag/AgI-Ag{sub 2}CO{sub 3} hybrids were employed for Hg{sup 0} removal under fluorescent light. • Superoxide radical (·O{sub 2}{sup −}) played a key role in Hg{sup 0} removal. • NO exhibited a significant effect on Hg{sup 0} removal in comparison to SO{sub 2}. • The mechanism for enhanced Hg{sup 0} removal over Ag/AgI-Ag{sub 2}CO{sub 3} was proposed. - Abstract: A series of ternary Ag/AgI-Ag{sub 2}CO{sub 3} photocatalysts synthesized using a facile coprecipitation method were employed to investigate their performances of Hg{sup 0} removal in a wet scrubbing reactor. The hybrids were characterized by N{sub 2} adsorption-desorption, XRD, SEM-EDS, HRTEM, XPS, DRS and ESR. The photocatalytic activities of Hg{sup 0} removal were evaluated under fluorescent light. The results showed that AgI content, fluorescent light irradiation, reaction temperature all showed significant influences on Hg{sup 0} removal. NO exhibited significant effect on Hg{sup 0} removal in comparison to SO{sub 2}. Among these ternary Ag/AgI-Ag{sub 2}CO{sub 3} hybrids, Ag/AgI(0.1)-Ag{sub 2}CO{sub 3} showed the highest Hg{sup 0} removal efficiency, which could be ascribed to the effective separation of photogenerated electron-hole pairs between AgI and Ag{sub 2}CO{sub 3} and the surface plasmon resonance (SPR) effect in the visible region by metallic silver nanoparticles (Ag{sup 0} NPs). The trapping studies of reactive radicals showed that the superoxide radicals (·O{sub 2}{sup −}) may play a key role in Hg{sup 0} removal under fluorescent light. According to the experimental and characterization results, a possible photocatalytic oxidation mechanism for enhanced Hg{sup 0} removal over Ag/AgI(0.1)-Ag{sub 2}CO{sub 3} hybrid under fluorescent light was proposed.

  14. Peritoneal catheter fixation combined with straight upward tunnel and low implant position to prevent catheter malfunction.

    Science.gov (United States)

    Zhang, Qingyan; Jiang, Chunming; Zhu, Wei; Sun, Cheng; Xia, Yangyang; Tang, Tianfeng; Wan, Cheng; Shao, Qiuyuan; Liu, Jing; Jin, Bo; Zhang, Miao

    2018-03-01

    Catheter malfunction is the main reason for early peritoneal dialysis (PD) technique failure. This study aimed to evaluate the effect of a new surgery technique with catheter fixation to the lower abdominal wall combined with straight upward tunnel and low implant position in reducing catheter malfunction. Patients with end stage renal disease who received PD in our centre from January 2013 to December 2015 were involved in this study. They were randomly divided into three groups according to surgical technique: traditional open surgery group, modified open surgery group and modified open surgery with catheter fixation group. All patients were followed up for six months after surgery. Catheter- related complications were analyzed. A total of 152 patients were involved. Among them, 49 received traditional open surgery (TOS group), 49 received modified open surgery (MOS group), and 54 received modified open surgery with catheter fixation (MOS-F group). During follow-up, no patients (0%) in MOS-F group developed catheter malfunction which was significantly lower than that of the TOS group (0 vs 16.33%, P = 0.002). Although not statistically significant, the incidence of catheter malfunction was lower in MOS-F group than that in MOS group (0 vs 4.08%, P = 0.134). No significant difference was observed in the episodes of infection, bleeding, leakage, inflow or outflow pain, hernia and delayed wound healing among the three groups (all P > 0.05). Catheter fixation combined with straight upward tunnel and low implant position can effectively prevent catheter malfunction in PD catheter placement. © 2016 Asian Pacific Society of Nephrology.

  15. Malfunction of cardiac devices after radiotherapy without direct exposure to ionizing radiation: mechanisms and experimental data.

    Science.gov (United States)

    Zecchin, Massimo; Morea, Gaetano; Severgnini, Mara; Sergi, Elisabetta; Baratto Roldan, Anna; Bianco, Elisabetta; Magnani, Silvia; De Luca, Antonio; Zorzin Fantasia, Anna; Salvatore, Luca; Milan, Vittorino; Giannini, Gianrossano; Sinagra, Gianfranco

    2016-02-01

    Malfunctions of cardiac implantable electronical devices (CIED) have been described after high-energy radiation therapy even in the absence of direct exposure to ionizing radiation, due to diffusion of neutrons (n) causing soft errors in inner circuits. The purpose of the study was to analyse the effect of scattered radiation on different types and models of CIED and the possible sources of malfunctions. Fifty-nine explanted CIED were placed on an anthropomorphous phantom of tissue-equivalent material, and a high-energy photon (15 MV) radiotherapy course (total dose = 70 Gy) for prostate treatment was performed. All devices were interrogated before and after radiation. Radiation dose, the electromagnetic field, and neutron fluence at the CIED site were measured. Thirty-four pacemakers (PM) and 25 implantable cardioverter-defibrillators (ICD) were analysed. No malfunctions were detected before radiation. After radiation a software malfunction was evident in 13 (52%) ICD and 6 (18%) PM; no significant electromagnetic field or photon radiations were detected in the thoracic region. Neutron capture was demonstrated by the presence of the (198)Au((197)Au + n) or (192)Ir((191)Ir + n) isotope activation; it was significantly greater in ICD than in PM and non-significantly greater in damaged devices. A greater effect in St Jude PM (2/2 damaged), Boston (9/11), and St Jude ICD (3/6) and in older ICD models was observed; the year of production was not relevant in PM. High-energy radiation can cause different malfunctions on CIED, particularly ICD, even without direct exposure to ionizing radiation due to scattered radiation of neutrons produced by the linear accelerator. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  16. Fluorescence uranium determination

    International Nuclear Information System (INIS)

    Fernandez Cellini, R.; Crus Castillo, F. de la; Barrera Pinero, R.

    1960-01-01

    An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs

  17. Examining Thermally Sprayed Coats By Fluorescence Microscopy

    Science.gov (United States)

    Street, Kenneth W., Jr.; Leonhardt, Todd A.

    1994-01-01

    True flaws distinquished from those induced by preparation of specimens. Fluorescence microscopy reveals debonding, porosity, cracks, and other flaws in specimens of thermally sprayed coating materials. Specimen illuminated, and dye it contains fluoresces, emitting light at different wavelength. Filters emphasize contrast between excitation light and emission light. Specimen viewed directly or photographed on color film.

  18. 40 CFR 63.1007 - Pumps in light liquid service standards.

    Science.gov (United States)

    2010-07-01

    ... malfunction) greater than the pump stuffing box pressure; or (B) Equipped with a barrier fluid degassing... system that purges the barrier fluid into a process stream. (iii) The barrier fluid is not in light...

  19. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses the foundati......Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  20. Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions.

    Science.gov (United States)

    Lee, Jong-Beom; Ahn, Ho-Young; Lee, Hong-Jae; Yang, Ji-Ho; Yi, Jin-Seok; Lee, Il-Woo

    2017-01-01

    The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH 2 O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH 2 O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH 2 O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH 2 O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant ( p =0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Under-drainage of CSF should be suspected if CSF lumbar tapping

  1. Fluorescence Correlation Spectroscopy Using Octadecylrhodamine B as a Specific Micelle-Binding Fluorescent Tag, Light Scattering and Tapping Mode Atomic Force Microscopy Studies of Amphiphilic Water-Soluble Block Copolymer Micelles

    Czech Academy of Sciences Publication Activity Database

    Humpolíčková, J.; Procházka, K.; Hof, Martin; Tuzar, Zdeněk; Špírková, Milena

    2003-01-01

    Roč. 19, - (2003), s. 4111-4119 ISSN 0743-7463 R&D Projects: GA MŠk LN00A032; GA ČR GA203/01/0536; GA ČR GA203/01/0735 Institutional research plan: CEZ:AV0Z4050913; CEZ:AV0Z4040901 Keywords : fluorescence * spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.098, year: 2003

  2. Multiple Chaotic Central Pattern Generators with Learning for Legged Locomotion and Malfunction Compensation

    DEFF Research Database (Denmark)

    Ren, Guanjiao; Chen, Weihai; Dasgupta, Sakyasingha

    2015-01-01

    on a simulated annealing algorithm. In a normal situation, the CPGs synchronize and their dynamics are identical. With leg malfunction or disability, the CPGs lose synchronization leading to independent dynamics. In this case, the learning mechanism is applied to automatically adjust the remaining legs...... in a physical simulation of a quadruped as well as a hexapod robot and finally in a real six-legged walking machine called AMOSII. The experimental results presented here reveal that using multiple CPGs with learning is an effective approach for adaptive locomotion generation where, for instance, different body...... chaotic CPG controller has difficulties dealing with leg malfunction. Specifically, in the scenarios presented here, its movement permanently deviates from the desired trajectory. To address this problem, we extend the single chaotic CPG to multiple CPGs with learning. The learning mechanism is based...

  3. Vagal Nerve Stimulator Malfunction with Change in Neck Position: Case Report and Literature Review.

    Science.gov (United States)

    D'Agostino, Erin; Makler, Vyacheslav; Bauer, David F

    2018-06-01

    Vagal nerve stimulation is a safe and well-tolerated treatment for drug-resistant epilepsy. Complications and failure of the device can result from lead fracture, device malfunction, disconnection, or battery displacement and can result in a variety of symptoms. We present an interesting case of stimulator malfunction with increased impedance change seen only with a change in head position. The patient is a 25-year-old male with a vagal nerve stimulator (VNs) placed for medically refractory epilepsy who presented with neck pain and an electrical pulling sensation in his neck whenever he turned his head to the right. Initial interrogation of the VNs showed normal impedance. Subsequent interrogation with the patient's head turned found increased impedance only when the head was turned to the right. The patient had successful removal and replacement of the device with resolution of his preoperative complaints. Partial lead fracture was seen at explant. VNs malfunction can present in atypical ways. Positional maneuvers may help with its timely diagnosis. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. RIG-1 expression is associated with sexual malfunctions of female type 2 diabetic patients

    Directory of Open Access Journals (Sweden)

    Batool Hajebrahimi

    2017-03-01

    Full Text Available Introduction: The patients with type 2 diabetes (T2D suffer from the malfunctions of the sexual behaviors, and several mechanisms have been proposed to describe these disorders. The innate immunity may be involved in the malfunctions of T2D patients. Melanoma differentiation-associated protein 5 (MDA5 and retinoic acid (RA-inducible gene 1 (RIG-1, as the innate immunity receptors, are the responsible molecules for the activation of some intracellular signaling pathways and the induction of inflammation. Thus, this study aimed to examine the molecules which may participate in the induction/stimulation of sexual malfunctions in the female T2D patients. Methods: Sexual functions were evaluated in 41 female T2D patients using the Female Sexual Function Index (FSFI questionnaire. Real-time polymerase chain reaction (PCR technique was used to quantify MDA5 and RIG-1 mRNA levels. Results: Results showed that increased RIG-1 mRNA levels were significantly associated with the bad orgasm in the female T2D patients compared to the female patients with good orgasm. Expression of RIG-1 and MDA5 levels were not associated with other sexual functions’ criteria. Conclusion: The findings of this study demonstrated that bad orgasm is associated with the increased RIG-1 expression. Consequently, the correlation between inflammation and bad orgasm in a RIG-1 dependent manner is suggested.

  5. Increasing Mud Pump Motor Reliability against Malfunctions of DC Motor Excitation System

    Science.gov (United States)

    Nikulin, O. V.; Shabanov, V. A.

    2017-10-01

    The most widely used drilling machinery, such as mud pumps, draw-works, and rotors, use direct-current (DC) motors with independent excitation as the electric drive. Drilling machinery drives operate in harsh ambient conditions, including those with the presence of moisture, dust and vibration, which increases the malfunction rate of both drilling equipment and their electric drives. One of the frequently encountered malfunctions are DC motor excitation coil faults, which disrupt the normal functioning of electric drives, often leading to shutdown of the drilling process. In a four-pole DC motor, the malfunction of one coil leads to lack of excitation current in just one coil pair, while the other pair remains functional. In this case, DC motors and drilling equipment can remain operational, which would allow for continuing the drilling process. This paper considers the possibility of operation of a DC motor on a drilling rig in those cases when one pair of excitation coils is non-functional, and describes the device for switching between the excitation coils and the auxiliary winding in a DC motor with independent excitation.

  6. An Experimental Study of Emission and Combustion Characteristics of Marine Diesel Engine with Fuel Injector Malfunctions

    Directory of Open Access Journals (Sweden)

    Kowalski Jerzy

    2016-01-01

    Full Text Available The presented paper shows the results of the laboratory study on the relation between chosen malfunctions of a fuel injector and composition of exhaust gas from the marine engine. The object of research is a marine 3-cylinder, four-stroke, direct injection diesel engine with an intercooler system. The engine was loaded with a generator and supercharged. The generator was electrically connected to the water resistance. The engine operated with a load between 50 kW and 250 kW at a constant speed. The engine load and speed, parameters of the turbocharger, systems of cooling, fuelling, lubricating and air exchange, were measured. Fuel injection and combustion pressures in all cylinders of the engine were also recorded. Exhaust gas composition was recorded by using a electrochemical gas analyzer. Air pressure, temperature and humidity were also recorded. Emission characteristics of the engine were calculated according to ISO 8178 standard regulations. During the study the engine operated at the technical condition recognized as „working properly” and with simulated fuel injector malfunctions. Simulation of malfunctions consisted in the increasing and decreasing of fuel injector static opening pressure, decalibration of fuel injector holes and clogging 2 neighboring of 9 fuel injector holes on one of 3 engine cylinders.

  7. Development of expert system on personal computer for diagnosis of nuclear reactor malfunctions

    International Nuclear Information System (INIS)

    Kameyama, Takanori; Uekata, Tomomichi; Oka, Yoshiaki; Kondo, Shunsuke; Togo, Yasumasa

    1988-01-01

    An expert system on a personal computer has been developed for diagnosis of malfunction of the fast experimental reactor 'JOYO'. Prolog-KABA is used as the language. The system diagnoses the event which causes scram or set-back of the control rod after an alarm at steady state operation. The knowledge base (KB) consists of several sub-KBs and a meta-KB. Using the forward chaining, the meta-KB decides which sub-KB should be accessed. The cause of the malfunction is identified in the sub-KB using the backward chaining. The terms expressing the characteristics of the events are involved in the production rules as attributes in order to use the Prolog function of pattern matching and back-tracking for efficient inference. The total number of the rules in the system is about 400. The experiments using the plant simulator of 'JOYO' have shown that malfunctions are successfully identified by the diagnosis system. It takes about 10s for each diagnosis using the 16-bits personal computer, PC-9801 VM. (author)

  8. Intelligent Engine Systems Work Element 1.2: Malfunction and Operator Error Reduction

    Science.gov (United States)

    Wiseman, Matthew

    2005-01-01

    Jet engines, although highly reliable and safe, do experience malfunctions that cause flight delays, passenger stress, and in some cases, in conjunction with inappropriate crew response, contribute to airplane accidents. On rare occasions, the anomalous engine behavior is not recognized until it is too late for the pilots to do anything to prevent or mitigate the resulting engine malfunction causing in-flight shutdowns (IFSDs), aborted takeoffs (ATOs), or loss of thrust control (LOTC). In some cases, the crew response to a myriad of external stimuli and existing training procedures is the source of the problem mentioned above. The problem is the reduction of jet engine malfunctions (IFSDs, ATOs, and LOTC) and inappropriate crew response (PSM+ICR) through the use of evolving and advanced technologies. The solution is to develop the overall system health maintenance architecture, detection and accommodation technologies, processes, and enhanced crew interfaces that would enable a significant reduction in IFSDs, ATOs, and LOTC. This program defines requirements and proposes a preliminary design concept of an architecture that enables the realization of the solution.

  9. Thermally stable green Ba(3)Y(PO(4))3:Ce(3+),Tb(3+) and red Ca(3)Y(AlO)(3)(BO(3))4:Eu(3+) phosphors for white-light fluorescent lamps.

    Science.gov (United States)

    Huang, Chien-Hao; Kuo, Te-Wen; Chen, Teng-Ming

    2011-01-03

    A class of thermal stable of green-emitting phosphors Ba(3)Y(PO(4))(3):Ce(3+),Tb(3+) (BYP:Ce(3+),Tb(3+)) and red-emitting phosphors Ca(3)Y(AlO)(3)(BO(3))(4):Eu(3+) (CYAB:Eu(3+)) for white-light fluorescent lamps were synthesized by high temperature solid-state reaction. We observed a decay of only 3% at 150 °C for BYP:0.25Ce3+,0.25Tb3+ (3% for LaPO4:Ce(3+),Tb(3+)), and a decay of 4% for CYAB:0.5Eu(3+) (7% for Y(2)O(3):Eu(3+), 24% for Y(2)O(2)S:Eu(3+)). The emission intensity of composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) is 70% of that of commercial LaPO(4):Ce(3+),Tb(3+) phosphors, and the CIE chromaticity coordinates are found to be (0.323, 0.534). The emission intensity of Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(4) is 70% and 83% of those of Y(2)O(3):Eu(3+) and Y(2)O(2)S:Eu(3+) phosphors, respectively, and the CIE chromaticity coordinates are redder (0.652, 0.342) than those of Y(2)O(3):Eu(3+) (0.645, 0.347) and Y(2)O(2)S:Eu(3+) (0.647, 0.343). A white-light fluorescent lamp is fabricated using composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) and Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(4) phosphors and matching blue-emitting phosphors. The results indicate that the quality of the brightness and color reproduction is suitable for application in shortwave UV fluorescent lamps. The white-light fluorescent lamp displays CIE chromaticity coordinates of x = 0.33, y = 0.35, a warm white light with a correlated color temperature of 5646 K, and a color-rendering index of Ra = 70.

  10. Hyperfine structure and isotope shift of transitions in YbI using UV and deep-UV cw laser light and the angular distribution of fluorescence radiation

    NARCIS (Netherlands)

    Zinkstok, R.T.; van Duijn, E.J.; Witte, S.; Hogervorst, W.

    2002-01-01

    Using the third harmonic of a cw titanium:sapphire laser, the hyperfine structure (HFS) and isotope shift (IS) of three deep-UV transitions of neutral Yb have been measured for the first time. By exploiting the angular distribution of fluorescence radiation, accurate and complete results are

  11. Demonstrating Fluorescence with Neon Paper and Plastic

    Science.gov (United States)

    Birriel, Jennifer J.; Roe, Clarissa

    2015-01-01

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

  12. A Novel Technique for Laparoscopic Salvage of CAPD Catheter Malfunction and Migration: The Santosh-PGI Hanging Loop Technique

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2015-01-01

    Full Text Available CAPD catheter malfunction is a common problem. Obstruction due to wrapping by appendices epiploicae of sigmoid colon has been rarely reported in literature. We report a case of CAPD catheter malfunction caused by catheter tip migration and obstruction by appendices epiploicae that was successfully managed by laparoscopic hanging loop technique. This case report highlights the ease with which epiplopexy can be performed and catheter tip migration can be prevented by this innovative laparoscopic procedure.

  13. Nanosecond fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Leskovar, B.

    1985-03-01

    This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are discussed. A short comparison of the most important deconvolution methods for numerical analysis of experimental data is given particularly with respect to the signal-to-noise ratio of the fluorescence signal. 22 refs., 8 figs

  14. Solid-state, ambient-operation thermally activated delayed fluorescence from flexible, non-toxic gold-nanocluster thin films: towards the development of biocompatible light-emitting devices

    Science.gov (United States)

    Talite, M. J. A.; Lin, H. T.; Jiang, Z. C.; Lin, T. N.; Huang, H. Y.; Heredia, E.; Flores, A.; Chao, Y. C.; Shen, J. L.; Lin, C. A. J.; Yuan, C. T.

    2016-08-01

    Luminescent gold nanoclusters (AuNCs) with good biocompatibility have gained much attention in bio-photonics. In addition, they also exhibit a unique photo-physical property, namely thermally activated delayed fluorescence (TADF), by which both singlet and triplet excitons can be harvested. The combination of their non-toxic material property and unique TADF behavior makes AuNCs biocompatible nano-emitters for bio-related light-emitting devices. Unfortunately, the TADF emission is quenched when colloidal AuNCs are transferred to solid states under ambient environment. Here, a facile, low-cost and effective method was used to generate efficient and stable TADF emissions from solid AuNCs under ambient environment using polyvinyl alcohol as a solid matrix. To unravel the underlying mechanism, temperature-dependent static and transient photoluminescence measurements were performed and we found that two factors are crucial for solid TADF emission: small energy splitting between singlet and triplet states and the stabilization of the triplet states. Solid TADF films were also deposited on the flexible plastic substrate with patterned structures, thus mitigating the waveguide-mode losses. In addition, we also demonstrated that warm white light can be generated based on a co-doped single emissive layer, consisting of non-toxic, solution-processed TADF AuNCs and fluorescent carbon dots under UV excitation.

  15. 40 CFR 63.1009 - Agitators in gas and vapor service and in light liquid service standards.

    Science.gov (United States)

    2010-07-01

    ..., or malfunction) greater than the agitator stuffing box pressure; or (B) Equipped with a barrier fluid... purges the barrier fluid into a process stream. (ii) The barrier fluid is not in light liquid service...

  16. 40 CFR 65.109 - Standards: Agitators in gas/vapor service and in light liquid service.

    Science.gov (United States)

    2010-07-01

    ... startup, shutdown, or malfunction) greater than the agitator stuffing box pressure; or (B) Equipped with a...-loop system that purges the barrier fluid into a process stream. (ii) The barrier fluid is not in light...

  17. CBDS: Constraint-based diagnostic system for malfunction identification in the nuclear power plant

    International Nuclear Information System (INIS)

    Ha, J.

    1992-01-01

    Traditional rule-based diagnostic expert systems use the experience of experts in the form of rules that associate symptoms with underlying faults. A commonly recognized failing of such systems is their narrow range of expertise and their inability to recognize problems outside this range of expertise. A model base diagnostic system isolating malfunctioning components-CBDS, the Constraint based Diagnostic System-has been developed. Since the intended behavior of a device is more predictable than unintended behaviors (faults), a model based system using the intended behavior has a potential to diagnose unexpected malfunctions by considering faults as open-quotes anything other than the intended behavior.close quotes As a knowledge base, the CBDS generates and decomposes a constraint network based on the structure and behavior model, which are represented symbolically in algebraic equations. Behaviors of generic components are organized in a component model library. Once the library is available, actual domain knowledge can be represented by declaring component types and their connections. To capture various plant knowledge, the mixed model was developed which allow the use of different parameter types in one equation by defining various operators. The CBDS uses the general idea of model based diagnosis. It detects a discrepancy between observation and prediction using constraint propagation, which carriers and accumulates the assumptions when parameter values are deduced. When measured plant parameters are asserted into a constraint network and are propagated through the network, a discrepancy will be detected if there exists any malfunctioning component. The CBDS was tested in the Recirculation Flow Control System of a BWR, and has been shown to be able to diagnose unexpected events

  18. Intermittent voiding per urethra as an indicator of cutaneous vesicostomy malfunction.

    Science.gov (United States)

    Hojjat, Asal; Kajbafzadeh, Abdol-Mohammad; Sina, Alireza; Mazaheri, Tina; Rad, Mona Vahidi; Nezami, Behtash Ghazi; Mohammadinejad, Payam

    2015-01-01

    To present a new approach for management of cutaneous vesicostomy (CV) prolapse, with special emphasis on normal appearing vesicostomy may be malfunctioning. To introduce the application of temporary stoma-free drainage as a diagnostic and therapeutic tool. From December 2000 to September 2006, 66 children (61 males and 5 females) with CV were studied. The mean age at vesicostomy was 7 months (range 1-30), and the main underlying disease was posterior urethral valves (in 45 children, 68%). Indications for CV included significant hydroureteronephrosis (HUN) and recurrent urinary tract infection. Patients were followed up for complications and were treated based on our institutional approach. All patients with persistent upper tract dilatation and micturition per urethra underwent temporary bladder (via stoma) free drainage. Patients with stomal stenosis were managed either by a revision surgery or by simple dilatation and intermittent catheterization. Purse string suturing was applied in mucosal prolapses as the first choice. The complications were observed in 21 patients (31%), including twelve stomal stenosis, nine severe mucosal prolapses, and two recurrent urinary infections. HUN and significant voiding per urethra persisted following initial CV in 19 out of 66 patients (29%), eleven of which having normal appearing CVs. Seventeen of these patients were managed by temporary stoma-free drainage (accompanied by purse string suturing in mucosal prolapse), and two patients with severe stenosis underwent surgical revision. Temporary stoma-free drainage improved HUN in 94% of patients (16 of 17). Voiding per urethra is an indicator of CV malfunction, and temporary stoma-free drainage can be a diagnostic and therapeutic option in such children. A seemingly open CV may still be malfunctioning, and ureterovesical or intravesical obstructions should be considered if HUN does not improve following temporary stoma-free drainage.

  19. Fiber optical assembly for fluorescence spectrometry

    Science.gov (United States)

    Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

    2010-12-07

    A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

  20. Lighting Options for Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.S.

    1991-04-01

    This report covers many aspects of various lighting options for homes. Types of light sources described include natural light, artificial light, incandescent lamps, fluorescent lamps, and high intensity discharge lamps. A light source selection guide gives the physical characteristics of these, design considerations, and common applications. Color, strategies for efficient lighting, and types of lighting are discussed. There is one section giving tips for various situations in specific rooms. Rooms and types of fixtures are shown on a matrix with watts saved by using the recommended type lighting for that room and room location. A major emphasis of this report is saving energy by utilizing the most suitable, recommended lighting option. (BN)

  1. Artificial urethral sphincters: Value of plain film radiography in evaluation of prosthesis malfunction

    International Nuclear Information System (INIS)

    Rose, S.C.; Hansen, M.E.; Webster, G.; Dunnick, N.R.

    1987-01-01

    Case records were reviewed to determine the diagnostic efficacy of plain radiographs in the evaluation of inflatable artificial urethral sphincters. Of 84 patients with prostheses, 21 (25%) developed complications. Fluid leaks were found in 16 patients who presented with recurrent incontinence; plain radiographs demonstrated an interval decrease in balloon reservoir diameter. Kinked tubing, which was evident on plain films, caused acute urinary retention in three patients. However, plain radiographs failed to detect evidence of prosthesis erosion into the urethra in either of two patients with this complication. Although urethroscopy is needed to detect urethral erosion, plain radiographs are inexpensive and reliable in the initial evaluation of artifical sphincter malfunction

  2. Human Errors - A Taxonomy for Describing Human Malfunction in Industrial Installations

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1982-01-01

    This paper describes the definition and the characteristics of human errors. Different types of human behavior are classified, and their relation to different error mechanisms are analyzed. The effect of conditioning factors related to affective, motivating aspects of the work situation as well...... as physiological factors are also taken into consideration. The taxonomy for event analysis, including human malfunction, is presented. Possibilities for the prediction of human error are discussed. The need for careful studies in actual work situations is expressed. Such studies could provide a better...

  3. Immune malfunction in the GPR39 zinc receptor of knockout mice

    DEFF Research Database (Denmark)

    Młyniec, Katarzyna; Trojan, Ewa; Ślusarczyk, Joanna

    2016-01-01

    Depression is a serious psychiatric disorder affecting not only the monaminergic, glutamatergic, and GABAergic neurosystems, but also the immune system. Patients suffering from depression show disturbance in the immune parameters as well as increased susceptibility to infections. Zinc is well known...... as an anti-inflammatory agent, and its link with depression has been proved, zinc deficiency causing depression- and anxiety-like behavior with immune malfunction. It has been discovered that trace-element zinc acts as a neurotransmitter in the central nervous system via zinc receptor GPR39. In this study we...

  4. Comparison of the PLCS malfunction event analyses by using the CESEC III and MEDUSA codes

    International Nuclear Information System (INIS)

    Oh, Myung Taek; Park, Chan Eok; Kim, Shin Whan; Seo, Jong Tae

    2004-01-01

    The MEDUSA is a code developed by Korea Power Engineering Company (KOPEC) for non-LOCA and LOCA analysis, providing two-fluid, three-field representation of two-phase flow. In this paper, as an effort to verify the MEDUSA code, comparative simulation for Pressurizer Level Control System (PLCS) malfunction with loss of off-site power is performed for UCN 3 and 4 plants. The results by the MEDUSA are compared with those calculated by the CESEC-III, a licensing analysis code used for Korean Standard Nuclear Power Plant (KSNP)

  5. Imaging lysosomal highly reactive oxygen species and lighting up cancer cells and tumors enabled by a Si-rhodamine-based near-infrared fluorescent probe.

    Science.gov (United States)

    Zhang, Hongxing; Liu, Jing; Liu, Chenlu; Yu, Pengcheng; Sun, Minjia; Yan, Xiaohan; Guo, Jian-Ping; Guo, Wei

    2017-07-01

    Lysosomes have recently been regarded as the attractive pharmacological targets for selectively killing of cancer cells via lysosomal cell death (LCD) pathway that is closely associated with reactive oxygen species (ROS). However, the details on the ROS-induced LCD of cancer cells are still poorly understood, partially due to the absence of a lysosome-targetable, robust, and biocompatible imaging tool for ROS. In this work, we brought forward a Si-rhodamine-based fluorescent probe, named PSiR, which could selectively and sensitively image the pathologically more relavent highly reactive oxygen species (hROS: HClO, HO, and ONOO - ) in lysosomes of cancer cells. Compared with many of the existing hROS fluorescent probes, its superiorities are mainly embodied in the high stability against autoxidation and photoxidation, near-infrared exitation and emission, fast fluorescence off-on response, and specific lysosomal localization. Its practicality has been demonstrated by the real-time imaging of hROS generation in lysosomes of human non-small-cell lung cancer cells stimulated by anticancer drug β-lapachone. Moreover, the probe was sensitive enough for basal hROS in cancer cells, allowing its further imaging applications to discriminate not only cancer cells from normal cells, but also tumors from healthy tissues. Overall, our results strongly indicated that PSiR is a very promising imaging tool for the studies of ROS-related LCD of cancer cells, screening of new anticancer drugs, and early diagnosis of cancers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. New light on a dark subject: On the use of fluorescence data to deduce redox states of natural organic matter (NOM)

    Science.gov (United States)

    Macalady, Donald L.; Walton-Day, Katherine

    2009-01-01

    This paper reports the use of excitation-emission matrix fluorescence spectroscopy (EEMS), parallel factor statistical analysis (PARAFAC), and oxidation-reduction experiments to examine the effect of redox conditions on PARAFAC model results for aqueous samples rich in natural organic matter. Fifty-four aqueous samples from 11 different geographic locations and two plant extracts were analyzed untreated and after chemical treatments or irradiation were used in attempts to change the redox status of the natural organic matter. The EEMS spectra were generated and modeled using a PARAFAC package developed by Cory and McKnight (2005). The PARAFAC model output was examined for consistency with previously reported relations and with changes expected to occur upon experimental oxidation and reduction of aqueous samples. Results indicate the implied fraction of total sample fluorescence attributed to quinone-like moieties was consistent (0.64 to 0.78) and greater than that observed by Cory and McKnight (2005). The fraction of the quinone-like moieties that was reduced (the reducing index, RI) showed relatively little variation (0.46 to 0.71) despite attempts to alter the redox status of the natural organic matter. The RI changed little after reducing samples using zinc metal, oxidizing at high pH with air, or irradiating with a Xenon lamp. Our results, however, are consistent with the correlations between the fluorescence indices (FI) of samples and the ratio of PARAFAC fitting parameters suggested by Cory and McKnight (2005), though we used samples with a much narrower range of FI values.

  7. Fluorescing macerals from wood precursors

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S A; Bensley, D F

    1987-01-01

    A preliminary investigation into the origin of wood-derived macerals has established the existence of autofluorescent maceral precursors in the secondary xylem of swamp-inhabiting plant species. The optical character and fluorescent properties of microtomed thin-sections of modern woods from the Florida Everglades and Okefenokee Swamp, Georgia are compared to the character and properties of their peatified equivalents from various Everglades and Okefenokee peat horizons and their lignitic equivalents from the Brandon lignite of Vermont and the Trail Ridge lignitic peat from northern Florida. The inherent fluorescence of woody cell walls is believed to be caused by lignin though other cell wall components may contribute. The fluorescence spectra for several wood and cell types had a ..gamma../sub m//sub a//sub x/ of 452 nm and Q value of 0.00. The color as observed in blue light and the spectral geometry as measured in UV light of peatified and lignitic woody cell walls (potential textinites) may change progressively during early coalification. Cell wall-derived maceral material is shown to maintain its fluorescing properties after being converted to a structureless material, perhaps a corpohuminite or humodetrinite precursor. Fluorescing xylem cell contents, such as condensed tannins or essential oils, can maintain the fluorescent character through early coalification. Xylem cell walls and xylem cell contents are shown to provide fluorescing progenitor materials which would not require subsequent infusion with 'lipid' materials to account for their fluorescence as phytoclast material or as macerals in coal. 35 references.

  8. Temperature effects on Microalgal Photosynthesis-Light responses measured by O2 production, Pulse-Amplitude-Modulated Fluorescence, and 14C assimilation

    DEFF Research Database (Denmark)

    Hancke, Kasper; Hancke, Torunn; Olsen, Lasse M.

    2008-01-01

    Short-term temperature effects on photosynthesis were investigated by measuring O2 production, PSII-fluorescence kinetics, and 14C-incorporation rates in monocultures of the marine phytoplankton species Prorocentrum minimum (Pavill.) J. Schiller (Dinophyceae), Prymnesium parvum f. patelliferum ( J....... C. Green, D. J. Hibberd et Pienaar) A. Larsen (Coccolithophyceae), and Phaeodactylum tricornutum Bohlin (Bacillariophyceae), grown at 15 oC and 80 umol photons m-2 s-1. Photosynthesis versus irradiance curves were measured at seven temperatures (0oC to 30oC) by all three approaches. The maximum...

  9. Stress tolerance and stress-induced injury in crop plants measured by chlorophyll fluorescence in vivo: chilling, freezing, ice cover, heat, and high light.

    Science.gov (United States)

    Smillie, R M; Hetherington, S E

    1983-08-01

    The proposition is examined that measurements of chlorophyll fluorescence in vivo can be used to monitor cellular injury caused by environmental stresses rapidly and nondestructively and to determine the relative stress tolerances of different species. Stress responses of leaf tissue were measured by F(R), the maximal rate of the induced rise in chlorophyll fluorescence. The time taken for F(R) to decrease by 50% in leaves at 0 degrees C was used as a measure of chilling tolerance. This value was 4.3 hours for chilling-sensitive cucumber. In contrast, F(R) decreased very slowly in cucumber leaves at 10 degrees C or in chilling-tolerant cabbage leaves at 0 degrees C. Long-term changes in F(R) of barley, wheat, and rye leaves kept at 0 degrees C were different in frost-hardened and unhardened material and in the latter appeared to be correlated to plant frost tolerance. To simulate damage caused by a thick ice cover, wheat leaves were placed at 0 degrees C under N(2). Kharkov wheat, a variety tolerant of ice encapsulation, showed a slower decrease in F(R) than Gatcher, a spring wheat. Relative heat tolerance was also indicated by the decrease in F(R) in heated leaves while changes in vivo resulting from photoinhibition, ultraviolet radiation, and photobleaching can also be measured.

  10. Combination of sealed source and radiotracer technique to understand malfunctioning in a chemical plant

    Energy Technology Data Exchange (ETDEWEB)

    Yelgaonkar, V.N. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)], E-mail: vivekyel@rediffmail.com; Jayakumar, T.K.; Singh, Sudhir; Sharma, M.K. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)

    2009-07-15

    Pure terphthalic acid (PTA) is produced by the oxidation of paraxylene in an oxidation reactor of a PTA plant. Since the reaction is exothermic, the temperature rises above 210 deg. C. Vapours formed in the reactor are passed through a series of heat exchangers and the cooled liquid is fed back to the reactor, which flows to the reactor by gravity. In one of the heat exchangers, improper flow distribution in the inlet and outlet pipelines was suspected. Maldistribution of flow in the heat exchanger was also suspected. Gamma scanning of the pipelines and a radiotracer experiment were carried out in the heat exchanger to study the malfunctioning. A specially fabricated pipe scanner was used to scan both 24 in diameter and 16 in diameter pipelines. From gamma scanning of the pipelines mostly on the bends, absence of the full bore flow of the liquid was observed. Presence of vapours along with the liquid could be obstructing the liquid flow, thereby causing the malfunctioning. A radiotracer experiment was also carried out to study the flow pattern in the heat exchanger. From the experiment, mean residence time of the heat exchanger was estimated as 470 s, which theoretically should be about 102 s. It indicated that the flow is decelerated in the heat exchanger because of the presence of vapour lock in the tube side.

  11. An enhanced data visualization method for diesel engine malfunction classification using multi-sensor signals.

    Science.gov (United States)

    Li, Yiqing; Wang, Yu; Zi, Yanyang; Zhang, Mingquan

    2015-10-21

    The various multi-sensor signal features from a diesel engine constitute a complex high-dimensional dataset. The non-linear dimensionality reduction method, t-distributed stochastic neighbor embedding (t-SNE), provides an effective way to implement data visualization for complex high-dimensional data. However, irrelevant features can deteriorate the performance of data visualization, and thus, should be eliminated a priori. This paper proposes a feature subset score based t-SNE (FSS-t-SNE) data visualization method to deal with the high-dimensional data that are collected from multi-sensor signals. In this method, the optimal feature subset is constructed by a feature subset score criterion. Then the high-dimensional data are visualized in 2-dimension space. According to the UCI dataset test, FSS-t-SNE can effectively improve the classification accuracy. An experiment was performed with a large power marine diesel engine to validate the proposed method for diesel engine malfunction classification. Multi-sensor signals were collected by a cylinder vibration sensor and a cylinder pressure sensor. Compared with other conventional data visualization methods, the proposed method shows good visualization performance and high classification accuracy in multi-malfunction classification of a diesel engine.

  12. Andrographolide Attenuates LPS-Induced Cardiac Malfunctions Through Inhibition of IκB Phosphorylation and Apoptosis in Mice

    Directory of Open Access Journals (Sweden)

    Jinlong Zhang

    2015-11-01

    Full Text Available Background/Aims: Cardiac malfunction is a common complication in sepsis and significantly increases the mortality of patients in septic shock. However, no studies have examined whether andrographolide (And reduces LPS-induced myocardial malfunction. Methods: Left ventricular systolic and diastolic functions were examined using echocardiography. TNF-a and IL-1ß protein levels were detected by an enzyme-linked immunosorbent assay (ELISA. NO oxidation products were determined using Griess reagent. Protein expression levels of inhibitors of NF-κBa (IκB and phospho-IκB were determined via Western blot. Oxidative injury was determined by measuring myocardial lipid peroxidation and superoxide dismutase activity. Cardiac apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP nickend-labeling (TUNEL and cardiac caspase 3/7 activity. Results: And blunted LPS-induced myocardial malfunctions in mice. LPS induced TNF-a, IL-1ß, and NO production as well as I-κB phosphorylation. Cardiac apoptosis was attenuated via incubation with And, but the extent of oxidative injury remained unaffected. Conclusion: And prevents LPS-induced cardiac malfunctions in mice by inhibiting TNF-a, IL-1ß, and NO production, IκB phosphorylation, and cardiac apoptosis, indicating that And may be a potential agent for preventing myocardial malfunction during sepsis.

  13. An operational fluorescence system for crop assessment

    Science.gov (United States)

    Belzile, Charles; Belanger, Marie-Christine; Viau, Alain A.; Chamberland, Martin; Roy, Simon

    2004-03-01

    The development of precision farming requires new tools for plant nutritional stress monitoring. An operational fluorescence system has been designed for vegetation status mapping and stress detection at plant and field scale. The instrument gives relative values of fluorescence at different wavelengths induced by the two-excitation sources. Lightinduced fluorescence has demonstrated successful crop health monitoring and plant nutritional stress detection capabilities. The spectral response of the plants has first been measured with an hyperspectral imager using laser-induced fluorescence. A tabletop imaging fluorometer based on flash lamp technology has also been designed to study the spatial distribution of fluorescence on plant leaves. For field based non-imaging system, LED technology is used as light source to induce fluorescence of the plant. The operational fluorescence system is based on ultraviolet and blue LED to induce fluorescence. Four narrow fluorescence bands centered on 440, 520, 690 and 740nm are detected. The instrument design includes a modular approach for light source and detector. It can accommodate as many as four different light sources and six bands of fluorescence detection. As part of the design for field application, the instrument is compatible with a mobile platform equipped with a GPS and data acquisition system. The current system developed by Telops/GAAP is configured for potato crops fluorescence measurement but can easily be adapted for other crops. This new instrument offers an effective and affordable solution for precision farming.

  14. High-contrast fluorescence imaging based on the polarization dependence of the fluorescence enhancement using an optical interference mirror slide.

    Science.gov (United States)

    Yasuda, Mitsuru; Akimoto, Takuo

    2015-01-01

    High-contrast fluorescence imaging using an optical interference mirror (OIM) slide that enhances the fluorescence from a fluorophore located on top of the OIM surface is reported. To enhance the fluorescence and reduce the background light of the OIM, transverse-electric-polarized excitation light was used as incident light, and the transverse-magnetic-polarized fluorescence signal was detected. As a result, an approximate 100-fold improvement in the signal-to-noise ratio was achieved through a 13-fold enhancement of the fluorescence signal and an 8-fold reduction of the background light.

  15. Charge-trapping effect of doped fluorescent dye on the electroluminescent processes and its performance in polymer light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Ye Tengling; Chen Zhenyu; Chen Jiangshan [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Ma Dongge, E-mail: mdg1014@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China)

    2010-11-15

    We have measured the temperature dependence of the steady-state current-voltage (I-V) characteristics and the transient electroluminescent (EL) characteristics in 4-(dicyanomethylene)-2-t-propyl-6-(1,1,7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped polyfluorene devices to study the charge-trapping effect of DCJTB fluorescent dye on luminescence processes and on device performance. Physical and chemical analyses prove that DCJTB molecules serve both as electron and hole traps, and the charge-trapping effect is more sensitive against the electrons than the holes at the low dopant concentration. This intrinsic characteristic causes the electron to be injected into the emitting layer first and then trapped in the bulk, producing a strong effect on device performance.

  16. Time-resolved fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gustavsson, Thomas; Mialocq, Jean-Claude

    2007-01-01

    This article addresses the evolution in time of light emitted by a molecular system after a brief photo-excitation. The authors first describe fluorescence from a photo-physical point of view and discuss the characterization of the excited state. Then, they explain some basic notions related to fluorescence characterization (lifetime and decays, quantum efficiency, so on). They present the different experimental methods and techniques currently used to study time-resolved fluorescence. They discuss basic notions of time resolution and spectral reconstruction. They briefly present some conventional methods: intensified Ccd cameras, photo-multipliers and photodiodes associated with a fast oscilloscope, and phase modulation. Other methods and techniques are more precisely presented: time-correlated single photon counting (principle, examples, and fluorescence lifetime imagery), streak camera (principle, examples), and optical methods like the Kerr optical effect (principle and examples) and fluorescence up-conversion (principle and theoretical considerations, examples of application)

  17. The structure of an expert system to diagnose and supply a corrective procedure for nuclear power plant malfunctions

    International Nuclear Information System (INIS)

    Hajek, B.K.; Stasenko, J.E.; Hashemi, S.; Bhatnagar, R.; Yamada, N.; Punch, W.F. III.

    1987-01-01

    Two prototype knowledge based systems have been developed at the Ohio State University. These systems were the result of collaboration between the Nuclear Engineering Program and the Laboratory for Artificial Intelligence Research (LAIR). The first system uses hierarchical classification to diagnose malfunctions of the coolant system in a General Electric Boiling Water Reactor (BWR). The second system provides a plan of action, through a process of dynamic procedure synthesis, to stabilize the plant once an abnormal transient has occurred. The objective of this paper is to discuss a structure that will integrate the two systems. The combined system will be capable of informing plant personnel about the nature of malfunctions, and of supplying to the operator the most direct corrective procedure available. Two important features of the integrated system are faulty sensor detection, based on malfunction context and unlike sensor data, and procedure synthesis based on the initial state of the plant

  18. Fluorescence detection of esophageal neoplasia

    Science.gov (United States)

    Borisova, E.; Vladimirov, B.; Avramov, L.

    2008-06-01

    White-light endoscopy is well-established and wide used modality. However, despite the many technological advances that have been occurred, conventional endoscopy is suboptimal and usually detects advanced stage lesions. The limitations of standard endoscopy initiate development of spectroscopic techniques, additional to standard endoscopic equipment. One of the most sensitive approaches is fluorescence spectroscopy of gastrointestinal mucosa for neoplasia detection. In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. Excitation source has max of emission at 405 nm and light is delivered by the standard light guide of the endoscopic equipment. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to reabsorption of blood. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of 5-ALA/PpIX only in abnormal sites Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

  19. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  20. Malfunctions of Implantable Cardiac Devices in Patients Receiving Proton Beam Therapy: Incidence and Predictors

    International Nuclear Information System (INIS)

    Gomez, Daniel R.; Poenisch, Falk; Pinnix, Chelsea C.; Sheu, Tommy; Chang, Joe Y.; Memon, Nada; Mohan, Radhe; Rozner, Marc A.; Dougherty, Anne H.

    2013-01-01

    Purpose: Photon therapy has been reported to induce resets of implanted cardiac devices, but the clinical sequelae of treating patients with such devices with proton beam therapy (PBT) are not well known. We reviewed the incidence of device malfunctions among patients undergoing PBT. Methods and Materials: From March 2009 through July 2012, 42 patients with implanted cardiac implantable electronic devices (CIED; 28 pacemakers and 14 cardioverter-defibrillators) underwent 42 courses of PBT for thoracic (23, 55%), prostate (15, 36%), liver (3, 7%), or base of skull (1, 2%) tumors at a single institution. The median prescribed dose was 74 Gy (relative biological effectiveness; range 46.8-87.5 Gy), and the median distance from the treatment field to the CIED was 10 cm (range 0.8-40 cm). Maximum proton and neutron doses were estimated for each treatment course. All CIEDs were checked before radiation delivery and monitored throughout treatment. Results: Median estimated peak proton and neutron doses to the CIED in all patients were 0.8 Gy (range 0.13-21 Gy) and 346 Sv (range 11-1100 mSv). Six CIED malfunctions occurred in 5 patients (2 pacemakers and 3 defibrillators). Five of these malfunctions were CIED resets, and 1 patient with a defibrillator (in a patient with a liver tumor) had an elective replacement indicator after therapy that was not influenced by radiation. The mean distance from the proton beam to the CIED among devices that reset was 7.0 cm (range 0.9-8 cm), and the mean maximum neutron dose was 655 mSv (range 330-1100 mSv). All resets occurred in patients receiving thoracic PBT and were corrected without clinical incident. The generator for the defibrillator with the elective replacement indicator message was replaced uneventfully after treatment. Conclusions: The incidence of CIED resets was about 20% among patients receiving PBT to the thorax. We recommend that PBT be avoided in pacing-dependent patients and that patients with any type of CIED receiving

  1. EFFECT OF TEMPERATURE AND LIGHT ON THE PHOTOSYNTHESIS AS MEASURED BY CHLOROPHYLL FLUORESCENCE OF CULTURED Kappaphycus sp. (SAKOL STRAIN FROM INDONESIA

    Directory of Open Access Journals (Sweden)

    Lidemen Lidemen

    2013-12-01

    Full Text Available Photosynthetic performance of carrageenophyte (Solieriaceae; Rhodophyta cultured in Indonesia, Kappaphycus sp. (Sakol strain, was investigated at various temperature and light conditions related to their cultivation performance. A “pulse-amplitude modulatedchlorophyll fluorometer” (Diving-PAM was used to generate a rapid light curves (RLCs to provide estimates relative electron transport rates (rETR for over 10 temperatures (i.e., 16oC to 34oC and at nine photosynthetic active radiation (PAR levels, which ranged from 0 to 1,000 mol photons m-2 s-1. The initial slope (α, photo-inhibition coefficient (β, and the coefficient of maximum photosynthesis assuming no photo-inhibition (γ is calculated by fitting the RLCs on a nonlinear model by using a two-level hierarchical Bayesian model. The experimental results showed that Kappaphycus sp. required temperatures ranging from 26oC to 34oC to maintain their high levels of photosynthetic activity. Saturating irradiace (Ek at the temperature range occured ranging from 120 to 150 μmol photons m-2 s-1. The model equation that have been derived from this series experiment can be used to determine the requirement of temperature and light intensity (irradiance of any seaweed species.

  2. Light Sources and Lighting Circuits

    Science.gov (United States)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

  3. Crystallography and Molecular Arrangement of Polymorphic Monolayer J-Aggregates of a Cyanine Dye: Multiangle Polarized Light Fluorescence Optical Microscopy Study.

    Science.gov (United States)

    Prokhorov, Valery V; Pozin, Sergey I; Perelygina, Olga M; Mal'tsev, Eugene I

    2018-04-24

    The molecular orientation in monolayer J-aggregates of 3,3-di(γ-sulfopropyl)-5,5-dichlorotiamonomethinecyanine dye has been precisely estimated using improved linear polarization measurements in the fluorescence microscope in which a multiangle set of polarization data is obtained using sample rotation. The estimated molecular orientation supplemented with the previously established crystallographic constraints based on the analysis of the well-developed two-dimensional J-aggregate shapes unambiguously indicate the staircase type of molecular arrangement for striplike J-aggregates with the staircases oriented along strips. The molecular transition dipoles are inclined at an angle of ∼25° to the strip direction, whereas the characteristic strip vertex angle ∼45° is formed by the [100] and [1-10] directions of the monoclinic unit cell. Measurements of the geometry of partially unwound tubes and their polarization properties support the model of tube formation by close-packed helical winding of flexible monolayer strips. In the tubes, the long molecular axes are oriented at a small angle in the range of 5-15° to the normal to the tube axis providing low bending energy. At a nanoscale, high-resolution atomic force microscopy imaging of J-aggregate monolayers reveals a complex quasi-one-dimensional organization.

  4. Metal-Free Poly-Cycloaddition of Activated Azide and Alkynes toward Multifunctional Polytriazoles: Aggregation-Induced Emission, Explosive Detection, Fluorescent Patterning, and Light Refraction.

    Science.gov (United States)

    Wu, Yongwei; He, Benzhao; Quan, Changyun; Zheng, Chao; Deng, Haiqin; Hu, Rongrong; Zhao, Zujin; Huang, Fei; Qin, Anjun; Tang, Ben Zhong

    2017-09-01

    The metal-free click polymerization (MFCP) of activated alkynes and azides or activated azide and alkynes have been developed into powerful techniques for the construction of polytriazoles without the obsession of metallic catalyst residues problem. However, the MFCP of activated azides and alkynes is rarely applied in preparation of functional polytriazoles. In this paper, soluble multifunctional polytriazoles (PIa and PIb) with high weight-average molecular weights (M w up to 32 000) are prepared via the developed metal-free poly-cycloaddition of activated azide and alkynes in high yields (up to 90%). The resultant PIa and PIb are thermally stable, and show aggregation-induced emission characteristics, enabling their aggregates to detect explosives with superamplification effect. Moreover, thanks to their containing aromatic rings and polar moieties, PIa and PIb exhibit high refractive indices. In addition, they can also be cross-linked upon UV irradiation to generate 2D fluorescent patterning due to their remaining azide groups and containing ester groups. Thus, these multifunctional polytriazoles are potentially applicable in the optoelectronic and sensing fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Fluorescence microscopy.

    Science.gov (United States)

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

    2014-10-01

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

  6. Battery Malfunction of a Leadless Cardiac Pacemaker - A Worrisome Single-Center Experience.

    Science.gov (United States)

    Richter, Sergio; Döring, Michael; Ebert, Micaela; Bode, Kerstin; Müssigbrodt, Andreas; Sommer, Philipp; Husser, Daniela; Hindricks, Gerhard

    2018-03-14

    Leadless cardiac pacemaker (LCP) therapy has been established clinically as a feasible and safe alternative to conventional transvenous pacemaker therapy for patients with an indication for single-chamber right-ventricular pacing. 1-3 However, reports on loss of telemetry and pacing output due to abrupt battery failure called the safety of one of the two commercially available systems seriously into question. The initial battery advisory with the Nanostim™ LCP was issued by the manufacturer in October 2016, who instantly called a global stop to Nanostim™ implants. To this day, similar battery issues have not been described for the Micra™ transcatheter pacing system. Therefore, we thought to analyze the long-term pacemaker performance and rate of battery malfunction of the Nanostim™ LCP in our patient population.

  7. Overexposure of patients due to malfunctions or defects in radiation equipment

    International Nuclear Information System (INIS)

    Gill, J.R.

    1992-01-01

    Some 38 incidents involving patient overexposure due to malfunctions or defects in radiation equipment were notified to HSE between 1986 and 1990. Of these cases, 30 involved diagnostic X ray equipment, while the remainder involved nuclear medicine or radiotherapy equipment. Those cases involving X ray equipment are examined in detail and grouped into six categories. The numbers of patients affected varied. In one case an estimated 350 patients were affected: in another, 240; while 13 cases affected only a single patient. A very rough estimate of the collective effective dose equivalent in the 30 cases comes to 5 man sieverts. It is concluded that improvements are needed in fault finding procedures, and guidance is needed on consistent methods of dose estimation and reporting. Improvements for the longer term include the selection of reliable components during manufacture; application of HSE guidance in software design for programmable electronic systems; and equipment design to incorporate fault detection and inhibition of operation to prevent excessive exposures

  8. Early Events in Retinal Degeneration Caused by Rhodopsin Mutation or Pigment Epithelium Malfunction: Differences and Similarities

    Science.gov (United States)

    Di Pierdomenico, Johnny; García-Ayuso, Diego; Pinilla, Isabel; Cuenca, Nicolás; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Villegas-Pérez, María P.

    2017-01-01

    To study the course of photoreceptor cell death and macro and microglial reactivity in two rat models of retinal degeneration with different etiologies. Retinas from P23H-1 (rhodopsin mutation) and Royal College of Surgeon (RCS, pigment epithelium malfunction) rats and age-matched control animals (Sprague-Dawley and Pievald Viro Glaxo, respectively) were cross-sectioned at different postnatal ages (from P10 to P60) and rhodopsin, L/M- and S-opsin, ionized calcium-binding adapter molecule 1 (Iba1), glial fibrillary acid protein (GFAP), and proliferating cell nuclear antigen (PCNA) proteins were immunodetected. Photoreceptor nuclei rows and microglial cells in the different retinal layers were quantified. Photoreceptor degeneration starts earlier and progresses quicker in P23H-1 than in RCS rats. In both models, microglial cell activation occurs simultaneously with the initiation of photoreceptor death while GFAP over-expression starts later. As degeneration progresses, the numbers of microglial cells increase in the retina, but decreasing in the inner retina and increasing in the outer retina, more markedly in RCS rats. Interestingly, and in contrast with healthy animals, microglial cells reach the outer nuclei and outer segment layers. The higher number of microglial cells in dystrophic retinas cannot be fully accounted by intraretinal migration and PCNA immunodetection revealed microglial proliferation in both models but more importantly in RCS rats. The etiology of retinal degeneration determines the initiation and pattern of photoreceptor cell death and simultaneously there is microglial activation and migration, while the macroglial response is delayed. The actions of microglial cells in the degeneration cannot be explained only in the basis of photoreceptor death because they participate more actively in the RCS model. Thus, the retinal degeneration caused by pigment epithelium malfunction is more inflammatory and would probably respond better to interventions

  9. Aging and malfunction of valves in CANDU special safety systems. Phase 1

    International Nuclear Information System (INIS)

    1989-03-01

    Aging and wear related valve malfunctions have been reported in American nuclear generating systems. This report documents the first attempt to study these phenomena on a global basis in Canadian nuclear power plants. A general methodology outlines an approach to this type of study which is amenable to use within existing information structures. Nuclear regulatory requirements which influence the testing of valves in Canadian nuclear power plants are reviewed. The reporting systems which emanate from these requirements are discussed and sources of valve failure data are reviewed. It is determined that modifications to existing failure reporting systems are required before practical means of collecting data necessary for the analysis of age related valve malfunctions can be developed. In spite of limitations in reported failure data, a partial data base is compiled for valve failures in Special Safety Systems of domestic nuclear plants. Data are reported for the period 1982 to 1986. The valve population and basic parameters of each valve such as type, operator, function, etc., and the reported failures against this population are compiled and reviewed for evidence of time dependent versus random failure trends. Results suggest that there is no clear age related failure trend. In fact, some systems and stations, experienced a reduction in failure rates with years of servicing, suggesting that some earlier generic valve problems may have been solved. Present inspection, test, and maintenance practices are reviewed and their effectiveness for purposes of predicting or preventing incipient failures is assessed to be of moderate value. Modern failure prevention methods are highlighted and their applicability discussed

  10. When do the symptoms of autonomic nervous system malfunction appear in patients with Parkinson's disease?

    Science.gov (United States)

    De Luka, Silvio R; Svetel, Marina; Pekmezović, Tatjana; Milovanović, Branislav; Kostić, Vladimir S

    2014-04-01

    Dysautonomia appears in almost all patients with Parkinson's disease (PD) in a certain stage of their condition. The aim of our study was to detect the development and type of autonomic disorders, find out the factors affecting their manifestation by analyzing the potential association with demographic variables related to clinical presentation, as well as the symptoms of the disease in a PD patient cohort. The patients with PD treated at the Clinic of Neurology in Belgrade during a 2-year period, divided into 3 groups were studied: 25 de novo patients, 25 patients already treated and had no long-term levodopa therapy-related complications and 22 patients treated with levodopa who manifested levodopa-induced motor complications. Simultaneously, 35 healthy control subjects, matched by age and sex, were also analyzed. Autonomic nervous system malfunction was defined by Ewing diagnostic criteria. The tests, indicators of sympathetic and parasympathetic nervous systems, were significantly different in the PD patients as compared with the controls, suggesting the failure of both systems. However, it was shown, in the selected groups of patients, that the malfunction of both systems was present in two treated groups of PD patients, while de novo group manifested only sympathetic dysfunction. For this reason, the complete autonomic neuropathy was diagnosed only in the treated PD patients, while de novo patients were defined as those with the isolated sympathetic dysfunction. The patients with the complete autonomic neuropathy differed from the subjects without such neuropathy in higher cumulative and motor unified Parkinson's disease rating score (UPDRS) (p nervous system disturbances among PD patients from the near onset of disease, with a predominant sympathetic nervous system involvement. The patients who developed complete autonomic neuropathy (both sympathetic and parasympathetic) were individuals with considerable level of functional failure, more severe clinical

  11. Malfunction diagnosis and applications of stable adaptive schemes for a nuclear reactor system

    International Nuclear Information System (INIS)

    Fukuda, Toshio; Shibata, Heki.

    1979-01-01

    Malfunction diagnosis concerns a method to detect the abnormal phenomena during nuclear reactor operations, while stable adaptive schemes does the application of Model Reference Adaptive System (MRAS) to the nonlinear dynamics of a reactor for parameter identification and control. The new method for the malfunction diagnosis consists of the following ideas; an index defined as the sum of ratios of the square of a factor score to the contribution weight of the factor, which is evaluated by applying the multi-factor analysis technique to the data of the state of nuclear reactor systems like neutron flux, temperature, flow rate and so on. The excess of the index over some given threshold shows the reactor system would be in an abnormal state. Then a theory of optimal filtering by Kalman with the aid of the stochastic approximation is applied to estimate the neutron flux distribution at its abnormal state and subsequently the squared sum of difference between desirable and estimated flux distributions shows the spot at which the abnormal phenomena would have occurred in terms of the peak of its distribution. Parameter identification and adaptive control schemes are presented for a point reactor and a loosely-coupled-core reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both schemes are shown stable with new representations of the systems, which correspond to the nonminimal system representation, in the vein of the MRAS via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. Some experiments of parameter identification for the thermal-hydraulic system are carried out successfully using a simplified channel in which flow rate is varied in a binary form. (J.P.N.)

  12. Detection of Counterfeit Tequila by Fluorescence Spectroscopy

    Directory of Open Access Journals (Sweden)

    José Manuel de la Rosa Vázquez

    2015-01-01

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

  13. Functional disubstituted polyacetylenes: Synthesis, liquid crystallinity, light emission, and fluorescent photopatterning of biphenyl-containing poly(1-phenyl-octyne)s with different functional bridges.

    Science.gov (United States)

    Lam, Jacky W Y; Qin, Anjun; Dong, Yuping; Lai, Lo Ming; Häussler, Matthias; Dong, Yongqiang; Tang, Ben Zhong

    2006-11-02

    Biphenyl (Biph)-containing 1-phenyl-1-octynes and their polymers are synthesized, and the effects of functional bridge groups on the mesomorphic and optical properties of the polymers are studied. The nonmesomorphic disubstituted acetylene monomers (C6H13)C[triple bond]C(C6H4)O(CH2)12O-Biph-OC7H15 (1), (C6H13)C[triple bond]C(C6H4)O(CH2)11OOC-Biph-OC7H15 (2), and (C6H13)C[triple bond]C(C6H4)CO2(CH2)12OOC-Biph-OC7H15 (3) are prepared by multistep reaction routes and converted into their corresponding polymers P1-P3 by a WCl6-Ph4Sn catalyst. The structures and properties of the polymers are characterized and evaluated by NMR, TGA, DSC, POM, XRD, UV, and PL analyses. The mesogenic pendants have endowed the polymers with high thermal stability (> or =400 degrees C). While P1 exhibits no liquid crystallinity, P2 and P3 form enantiotropic S(A) phase with a monolayer structure. Upon photoexcitation, the polymers emit blue and blue-green lights of 460 and 480 nm, respectively, in THF with quantum efficiencies larger than 30%. UV irradiation of a thin film of P2 through a mask oxidizes and quenches the light emission of the exposed regions, generating a two-dimensional luminescent photoimage.

  14. Shunt malfunction causing acute neurological deterioration in 2 patients with previously asymptomatic Chiari malformation Type I. Report of two cases.

    Science.gov (United States)

    Elliott, Robert; Kalhorn, Stephen; Pacione, Donato; Weiner, Howard; Wisoff, Jeffrey; Harter, David

    2009-08-01

    Patients with symptomatic Chiari malformation Type I (CM-I) typically exhibit a chronic, slowly progressive disease course with evolution of symptoms. However, some authors have reported acute neurological deterioration in the setting of CM-I and acquired Chiari malformations. Although brainstem dysfunction has been documented in patients with CM-II and hydrocephalus or shunt malfunction, to the authors' knowledge only 1 report describing ventriculoperitoneal (VP) shunt malfunction causing neurological deterioration in a patient with CM-I exists. The authors report on their experience with the treatment of previously asymptomatic CM-I in 2 children who experienced quite different manifestations of acute neurological deterioration secondary to VP shunt malfunction. Presumably, VP shunt malfunction created a positive rostral pressure gradient across a stenotic foramen magnum, resulting in tetraparesis from foramen magnum syndrome in 1 patient and acute ataxia and cranial nerve deficits from syringobulbia in the other. Although urgent shunt revisions yielded partial recovery of neurological function in both patients, marked improvement occurred only after posterior fossa decompression.

  15. Using Noninvasive Brain Measurement to Explore the Psychological Effects of Computer Malfunctions on Users during Human-Computer Interactions

    Directory of Open Access Journals (Sweden)

    Leanne M. Hirshfield

    2014-01-01

    Full Text Available In today’s technologically driven world, there is a need to better understand the ways that common computer malfunctions affect computer users. These malfunctions may have measurable influences on computer user’s cognitive, emotional, and behavioral responses. An experiment was conducted where participants conducted a series of web search tasks while wearing functional near-infrared spectroscopy (fNIRS and galvanic skin response sensors. Two computer malfunctions were introduced during the sessions which had the potential to influence correlates of user trust and suspicion. Surveys were given after each session to measure user’s perceived emotional state, cognitive load, and perceived trust. Results suggest that fNIRS can be used to measure the different cognitive and emotional responses associated with computer malfunctions. These cognitive and emotional changes were correlated with users’ self-report levels of suspicion and trust, and they in turn suggest future work that further explores the capability of fNIRS for the measurement of user experience during human-computer interactions.

  16. Smart lighting using LED luminaries

    NARCIS (Netherlands)

    Bhardwaj, S.; Ozcelebi, T.; Lukkien, J.J.

    2010-01-01

    The target of a smart lighting system is to control light sources in an environment (e.g. home, office) adaptively according to user contexts and preferences. Literature work in this area focuses on traditional light sources such as incandescent and fluorescent lights, whereas this paper takes a

  17. Absorbance and fluorescence studies on porphyrin Nanostructures ...

    African Journals Online (AJOL)

    The aim of this work was to study some photophysical properties of PNR for application as light harvester in dye sensitized solar cells. These properties included absorbance, fluorescence, and fluorescence quantum yield and lifetime. The results of Transmission Electron Microscope (TEM) images showed the formation of ...

  18. Red and green fluorescence from oral biofilms

    NARCIS (Netherlands)

    Volgenant, C.M.C.; Hoogenkamp, M.A.; Krom, B.P.; Janus, M.M.; ten Cate, J.M.; de Soet, J.J.; Crielaard, W.; van der Veen, M.H.

    2016-01-01

    Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis.

  19. Lighting for Education.

    Science.gov (United States)

    Ontario Ministry of Colleges and Universities, Toronto.

    Some of the qualities and quantities that must be juggled to produce good lighting for educational facilities are analyzed with photographs, tables, and drawings. The three categories of lamps used for school lighting (incandescent, fluorescent, and high intensity discharge) are described; a lamp selection guide gives the design characteristics of…

  20. Impulse control disorder, lysosomal malfunction and ATP13A2 insufficiency in Parkinsonism.

    Science.gov (United States)

    Liu, Jun-Ping; Li, Jianfeng; Lu, Yanhua; Wang, Lihui; Chen, Gang

    2017-02-01

    Lysosomal transport of cargos in neurons is essential for neuronal proteostasis, transmission and functional motors and behaviours. Lysosomal malfunction including storage disorders is involved in the pathogenesis of Parkinson's disease (PD). Given the unclear molecular mechanisms of diverse defects in PD phenotypes, especially behavioural deficits, this mini review explores the cellular contexts of PD impulse control disorders and the molecular aspects of lysosomal cross-membrane transports. Focuses are paid to trace metal involvements in α-synuclein assembly in Lewy bodies, the functions and molecular interactions of ATP13A2 as ATPase transporters in lysosomal membranes for cross-membrane trafficking and lysosomal homeostasis, and our current understandings of the neural circuits in ICD. Erroneously polarized distributions of cargos such as metals and lipids on each side of lysosomal membranes triggered by gene mutations and deregulated expression of ATP13A2 may thus instigate sensing protein structural changes such as aggregations, organelle degeneration, and specific neuronal ageing and death in Parkinsonism. © 2016 John Wiley & Sons Australia, Ltd.

  1. Ares-I-X Vehicle Preliminary Range Safety Malfunction Turn Analysis

    Science.gov (United States)

    Beaty, James R.; Starr, Brett R.; Gowan, John W., Jr.

    2008-01-01

    Ares-I-X is the designation given to the flight test version of the Ares-I rocket (also known as the Crew Launch Vehicle - CLV) being developed by NASA. As part of the preliminary flight plan approval process for the test vehicle, a range safety malfunction turn analysis was performed to support the launch area risk assessment and vehicle destruct criteria development processes. Several vehicle failure scenarios were identified which could cause the vehicle trajectory to deviate from its normal flight path, and the effects of these failures were evaluated with an Ares-I-X 6 degrees-of-freedom (6-DOF) digital simulation, using the Program to Optimize Simulated Trajectories Version 2 (POST2) simulation framework. The Ares-I-X simulation analysis provides output files containing vehicle state information, which are used by other risk assessment and vehicle debris trajectory simulation tools to determine the risk to personnel and facilities in the vicinity of the launch area at Kennedy Space Center (KSC), and to develop the vehicle destruct criteria used by the flight test range safety officer. The simulation analysis approach used for this study is described, including descriptions of the failure modes which were considered and the underlying assumptions and ground rules of the study, and preliminary results are presented, determined by analysis of the trajectory deviation of the failure cases, compared with the expected vehicle trajectory.

  2. Uncovering the link between malfunctions in Drosophila neuroblast asymmetric cell division and tumorigenesis

    Directory of Open Access Journals (Sweden)

    Kelsom Corey

    2012-11-01

    Full Text Available Abstract Asymmetric cell division is a developmental process utilized by several organisms. On the most basic level, an asymmetric division produces two daughter cells, each possessing a different identity or fate. Drosophila melanogaster progenitor cells, referred to as neuroblasts, undergo asymmetric division to produce a daughter neuroblast and another cell known as a ganglion mother cell (GMC. There are several features of asymmetric division in Drosophila that make it a very complex process, and these aspects will be discussed at length. The cell fate determinants that play a role in specifying daughter cell fate, as well as the mechanisms behind setting up cortical polarity within neuroblasts, have proved to be essential to ensuring that neurogenesis occurs properly. The role that mitotic spindle orientation plays in coordinating asymmetric division, as well as how cell cycle regulators influence asymmetric division machinery, will also be addressed. Most significantly, malfunctions during asymmetric cell division have shown to be causally linked with neoplastic growth and tumor formation. Therefore, it is imperative that the developmental repercussions as a result of asymmetric cell division gone awry be understood.

  3. Synthesis and electroluminescent properties of blue fluorescent materials based on 9,9-diethyl-N,N-diphenyl-9 H-fluoren-2-amine substituted anthracene derivatives for organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seul Bee; Kim, Chanwoo; Park, Soo Na; Kim, Young Seok [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Lee, Ho Won [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

    2015-11-30

    Four 9,9-diethyl-N,N-diphenyl-9 H-fluoren-2-amine substituted anthracene derivatives have been designed and synthesized by Suzuki cross coupling reactions. To explore the electroluminescent properties of these blue materials, multilayer blue organic light-emitting diodes were fabricated in the following device structure: indium tin oxide (180 nm)/N,N’-diphenyl-N,N’-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine (50 nm)/blue emitting materials (1–4) (30 nm)/bathophenanthroline (30 nm)/lithium quinolate (2 nm)/Al (100 nm). All devices appeared excellent deep-blue emissions. Among them, a device exhibited a maximum luminance of 5686 cd/m{sup 2}, the luminous, power and external quantum efficiencies of 5.11 cd/A, 3.79 lm/W, and 4.06% with the Commission International de L'Eclairage coordinates of (0.15, 0.15) at 500 cd/m{sup 2}, respectively. - Highlights: • We synthesized blue fluorescent materials based on anthracene derivatives. • The EL efficiencies of these materials depend on the quantum yields in solid states. • These materials have great potential for applications as blue emitter in OLEDs.

  4. Holograms preparation using commercial fluorescent benzyl

    Energy Technology Data Exchange (ETDEWEB)

    Dorantes-GarcIa, V; Olivares-Perez, A; Ordonez-Padilla, M J; Mejias-Brizuela, N Y, E-mail: valdoga@Hotmail.com, E-mail: olivares@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Coordinacion de Optica, Calle Luis Enrique Erro N0 1, Santa Maria Tonantzintla, Puebla (Mexico)

    2011-01-01

    We have been able to make holograms with substances such as fluorescence thought of light blue laser to make transmissions holograms, using ammonium dichromate as photo-sensitizer and polyvinyl alcohol (PVA) as matrix. Ammonium dichromate inhibit the fluorescence properties of inks, both mixed in a (PVA) matrix, but we avoid this chemical reaction and we show the results to use the method of painting hologram with fluorescents ink and we describe how the diffraction efficiency parameter changes as a function of the ink absorbed by the emulsion recorded with the gratings, we got good results, making holographic gratings with a blue light from laser diode 470 nm. And we later were painting with fluorescent ink, integrating fluorescence characteristics to the hologram.

  5. Fluorescent microthermographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barton, D.L.

    1993-09-01

    In the early days of microelectronics, design rules and feature sizes were large enough that sub-micron spatial resolution was not needed. Infrared or IR thermal techniques were available that calculated the object`s temperature from infrared emission. There is a fundamental spatial resolution limitation dependent on the wavelengths of light being used in the image formation process. As the integrated circuit feature sizes began to shrink toward the one micron level, the limitations imposed on IR thermal systems became more pronounced. Something else was needed to overcome this limitation. Liquid crystals have been used with great success, but they lack the temperature measurement capabilities of other techniques. The fluorescent microthermographic imaging technique (FMI) was developed to meet this need. This technique offers better than 0.01{degrees}C temperature resolution and is diffraction limited to 0.3 {mu}m spatial resolution. While the temperature resolution is comparable to that available on IR systems, the spatial resolution is much better. The FMI technique provides better spatial resolution by using a temperature dependent fluorescent film that emits light at 612 nm instead of the 1.5 {mu}m to 12 {mu}m range used by IR techniques. This tutorial starts with a review of blackbody radiation physics, the process by which all heated objects emit radiation to their surroundings, in order to understand the sources of information that are available to characterize an object`s surface temperature. The processes used in infrared thermal imaging are then detailed to point out the limitations of the technique but also to contrast it with the FMI process. The FMI technique is then described in detail, starting with the fluorescent film physics and ending with a series of examples of past applications of FMI.

  6. Fluorescent Nanodiamonds in Biomedical Applications.

    Science.gov (United States)

    Mitura, Katarzyna Anna; Włodarczyk, Elżbieta

    2018-04-18

    Nanoparticles have an extended surface and a large surface area, which is the ratio of the size of the surfacearea to the volume. A functionalized surface can give rise to more modifications and therefore allows this nanomaterial to have new properties. Fluorescent molecules contain fluorophore, which is capable of being excited via the absorption of light energy at a specific wavelength and subsequently emitting radiation energy of a longer wavelength. A chemically modified surface of nanodiamond (ND; by carboxylation) demonstrated biocompatibility with DNA, cytochrome C, and antigens. In turn, fluorescent nanodiamonds (FNDs) belong to a group of new nanomaterials. Their surface can be modified by joining functional groups such as carboxyl, hydroxyl, or amino, after which they can be employed as a fluorescence agent. Their fluorescent properties result from defects in the crystal lattice. FNDs reach dimensions of 4-100 nm, have attributes such as photostability, long fluorescence lifetimes (10 ns), and fluorescence emission between 600 and 700 nm. They are also nontoxic, chemically inert, biocompatible, and environmentally harmless. The main purpose of this article was to present the medical applications of various types of modified NDs.

  7. Radiotherapy and risk of implantable cardioverter-defibrillator malfunctions: experimental data from direct exposure at increasing doses.

    Science.gov (United States)

    Zecchin, Massimo; Artico, Jessica; Morea, Gaetano; Severgnini, Mara; Bianco, Elisabetta; De Luca, Antonio; Fantasia, Anna Zorzin; Salvatore, Luca; Milan, Vittorino; Lucarelli, Matteo; Dissegna, Roberta; Cannatà, Antonio; Sinagra, Gianfranco

    2018-04-01

    During radiotherapy, in patients with implantable cardioverter-defibrillators (ICDs) malfunctions are considered more likely if doses more than 2 Gy reach the ICD site; however, most malfunctions occur with high-energy (>10 MV) radiations, and the risk is less defined using 6-MV linear accelerators. The purpose of the study is to experimentally evaluate the occurrence of malfunctions in ICDs radiated with a 6-MV linear accelerator at increasing photon doses. Thirty-two ICDs from all manufacturers (31 explanted and one demo) were evaluated; all devices with a sufficient battery charge underwent multiple radiations with a 6-MV photon beam reaching a cumulative dose at ICD site of 0.5, 1, 2, 3, 5 and 10 Gy and interrogated after every session. All antitachycardia therapies were left enabled; two ICDs were connected to a rhythm simulator (one simulating a complete atrioventricular block without ventricular activity) and visually monitored by external ECG and the ICD programmer during radiation. Thirteen ICDs were excluded before radiation because of battery depletion; after radiation up to the cumulative dose at the cardiac implantable electronic device site of 10 Gy, in the remaining 19 devices, programmation and battery charge remained unchanged and no switch to safety mode was observed; oversensing, pacing inhibition or inappropriate antitachycardia therapy were neither recorded nor visually observed during radiation. With a low-energy accelerator, neither malfunctions nor electromagnetic interferences were detected radiating the ICDs at doses usually reaching the ICD pocket during radiotherapy sessions. In this context, magnet application to avoid oversensing and inappropriate therapy seems, therefore, useless.

  8. Fluorescence detection of dental calculus

    Science.gov (United States)

    Gonchukov, S.; Biryukova, T.; Sukhinina, A.; Vdovin, Yu

    2010-11-01

    This work is devoted to the optimization of fluorescence dental calculus diagnostics in optical spectrum. The optimal wavelengths for fluorescence excitation and registration are determined. Two spectral ranges 620 - 645 nm and 340 - 370 nm are the most convenient for supra- and subgingival calculus determination. The simple implementation of differential method free from the necessity of spectrometer using was investigated. Calculus detection reliability in the case of simple implementation is higher than in the case of spectra analysis at optimal wavelengths. The use of modulated excitation light and narrowband detection of informative signal allows us to decrease essentially its diagnostic intensity even in comparison with intensity of the low level laser dental therapy.

  9. The structure of an expert system to diagnose and supply a corrective procedure for nuclear power plant malfunctions

    International Nuclear Information System (INIS)

    Hajek, B.K.; Stasenko, J.E.; Hashemi, S.; Bhatnagar, R.; Punch, W.F. III; Yamada, N.

    1987-01-01

    During the past two years, two prototype knowledge based systems have been developed at the Ohio State University. These systems were the result of collaboration between the Nuclear Engineering Program and the Laboratory for Artificial Intelligence Research (LAIR). The first system uses hierarchical classification to diagnose malfunctions of the coolant system in a General Electric Boiling Water Reactor (BWR). The second system provides a plan of action, through a process of dynamic procedure management, to stabilize the plant once an abnormal transient has occurred. The objective of this paper is to discuss the structure that has been designed to integrate the two systems. The combined system will be capable of informing plant personnel about the nature of malfunctions, and of supplying to the operator the most direct corrective procedure available. Two important features of the integrated system are faulty sensor detection, based on malfunction context and unlike sensor data, and procedure management based on the initial state of the plant. Since the two knowledge based systems were developed separately, the integration has required a separate component currently under development, the Plant Status Monitoring System (PSMS). The task of PSMS is to monitor plant parameters in order to detect an abnormal condition developing within the plant. Based on the nature of the event, PSMS is capable of directing control to either the procedure management or diagnosis component. The integrated system plays only an advisory role, and any suggested action would be executed by the plant personnel

  10. Bir1 Deletion Causes Malfunction of the Spindle Assembly Checkpoint and Apoptosis in Yeast

    International Nuclear Information System (INIS)

    Ren, Qun; Liou, Liang-Chun; Gao, Qiuqiang; Bao, Xiaoming; Zhang, Zhaojie

    2012-01-01

    Cell division in yeast is a highly regulated and well studied event. Various checkpoints are placed throughout the cell cycle to ensure faithful segregation of sister chromatids. Unexpected events, such as DNA damage or oxidative stress, cause the activation of checkpoint(s) and cell cycle arrest. Malfunction of the checkpoints may induce cell death. We previously showed that under oxidative stress, the budding yeast cohesin Mcd1, a homolog of human Rad21, was cleaved by the caspase-like protease Esp1. The cleaved Mcd1 C-terminal fragment was then translocated to mitochondria, causing apoptotic cell death. In the present study, we demonstrated that Bir1 plays an important role in spindle assembly checkpoint and cell death. Similar to H 2 O 2 treatment, deletion of BIR1 using a BIR1-degron strain caused degradation of the securin Pds1, which binds and inactivates Esp1 until metaphase-anaphase transition in a normal cell cycle. BIR1 deletion caused an increase level of ROS and mis-location of Bub1, a major protein for spindle assembly checkpoint. In wild type, Bub1 was located at the kinetochores, but was primarily in the cytoplasm in bir1 deletion strain. When BIR1 was deleted, addition of nocodazole was unable to retain the Bub1 localization on kinetochores, further suggesting that Bir1 is required to activate and maintain the spindle assembly checkpoint. Our study suggests that the BIR1 function in cell cycle regulation works in concert with its anti-apoptosis function.

  11. Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study.

    Science.gov (United States)

    Riva-Cambrin, Jay; Kestle, John R W; Holubkov, Richard; Butler, Jerry; Kulkarni, Abhaya V; Drake, James; Whitehead, William E; Wellons, John C; Shannon, Chevis N; Tamber, Mandeep S; Limbrick, David D; Rozzelle, Curtis; Browd, Samuel R; Simon, Tamara D

    2016-04-01

    OBJECT The rate of CSF shunt failure remains unacceptably high. The Hydrocephalus Clinical Research Network (HCRN) conducted a comprehensive prospective observational study of hydrocephalus management, the aim of which was to isolate specific risk factors for shunt failure. METHODS The study followed all first-time shunt insertions in children younger than 19 years at 6 HCRN centers. The HCRN Investigator Committee selected, a priori, 21 variables to be examined, including clinical, radiographic, and shunt design variables. Shunt failure was defined as shunt revision, subsequent endoscopic third ventriculostomy, or shunt infection. Important a priori-defined risk factors as well as those significant in univariate analyses were then tested for independence using multivariate Cox proportional hazard modeling. RESULTS A total of 1036 children underwent initial CSF shunt placement between April 2008 and December 2011. Of these, 344 patients experienced shunt failure, including 265 malfunctions and 79 infections. The mean and median length of follow-up for the entire cohort was 400 days and 264 days, respectively. The Cox model found that age younger than 6 months at first shunt placement (HR 1.6 [95% CI 1.1-2.1]), a cardiac comorbidity (HR 1.4 [95% CI 1.0-2.1]), and endoscopic placement (HR 1.9 [95% CI 1.2-2.9]) were independently associated with reduced shunt survival. The following had no independent associations with shunt survival: etiology, payer, center, valve design, valve programmability, the use of ultrasound or stereotactic guidance, and surgeon experience and volume. CONCLUSIONS This is the largest prospective study reported on children with CSF shunts for hydrocephalus. It confirms that a young age and the use of the endoscope are risk factors for first shunt failure and that valve type has no impact. A new risk factor-an existing cardiac comorbidity-was also associated with shunt failure.

  12. Development of ultrasound-assisted fluorescence imaging of indocyanine green.

    Science.gov (United States)

    Morikawa, Hiroyasu; Toyota, Shin; Wada, Kenji; Uchida-Kobayashi, Sawako; Kawada, Norifumi; Horinaka, Hiromichi

    2017-01-01

    Indocyanine green (ICG) accumulation in hepatocellular carcinoma means tumors can be located by fluorescence. However, because of light scattering, it is difficult to detect ICG fluorescence from outside the body. We propose a new fluorescence imaging method that detects changes in the intensity of ICG fluorescence by ultrasound-induced temperature changes. ICG fluorescence intensity decreases as the temperature rises. Therefore, it should theoretically be possible to detect tissue distribution of ICG using ultrasound to heat tissue, moving the point of ultrasound transmission, and monitoring changes in fluorescence intensity. A new probe was adapted for clinical application. It consisted of excitation light from a laser, fluorescence sensing through a light pipe, and heating by ultrasound. We applied the probe to bovine liver to image the accumulation of ICG. ICG emits fluorescence (820 nm) upon light irradiation (783 nm). With a rise in temperature, the fluorescence intensity of ICG decreased by 0.85 %/°C. The distribution of fluorescent ICG was detected using an ultrasonic warming method in a new integrated probe. Modulating fluorescence by changing the temperature using ultrasound can determine where ICG accumulates at a depth, highlighting its potential as a means to locate hepatocellular carcinoma.

  13. Compact Fluorescent Lights, Mercury, and the Landfill

    Science.gov (United States)

    2009-09-01

    danger is for women of childbearing age, pregnant women, nursing mothers, and young children. The exposure of unborn and young children can harm the...acceptable exposure limits for women of childbearing years and those who are pregnant or nursing . In USEPA’s 1997 Mercury Study Report to Congress, it was...known to be contaminated at higher levels, such as shark , swordfish, tilefish, and king mackerel. USEPA also hosts a web-based compilation of fish

  14. An optical method for reducing green fluorescence from urine during fluorescence-guided cystoscopy

    DEFF Research Database (Denmark)

    Lindvold, Lars René; Hermann, Gregers G

    2016-01-01

    Photodynamic diagnosis (PDD) of bladder tumour tissue significantly improves endoscopic diagnosis and treatment of bladder cancer in rigid cystoscopes in the operating theatre and thus reduces tumour recurrence. PDD comprises the use of blue light, which unfortunately excites green fluorescence...... this light source also is useful for exciting autofluorescence in healthy bladder mucosa. This autofluorescence then provides a contrast to the sensitized fluorescence (PDD) of tumours in the bladder....

  15. A fluorescence switch based on a controllable photochromic naphthopyran group

    International Nuclear Information System (INIS)

    Chen Lizhen; Wang Guang; Zhao Xiancai

    2011-01-01

    A fluorescence switch based on photoisomerization of naphthopyran (NP) has been designed by employing 2-(pyridin-2-yl)-benzimidazole (BPI) and the naphthopyran containing two pyran rings (NP) as fluorescent dye and photochromic compound, respectively. The fluorescence switch of benzimidazole derivative can be modulated either by controlling the irradiation time of UV light or by adjusting the amount ratio of fluorescent benzimidazole derivative to photochromic naphthopyran in both solution and polymethyl methacrylate (PMMA) film. The experimental results indicated that the decrease of fluorescence intensity of benzimidazole derivative is attributed to the interaction of benzimidazole with naphthopyran. - Highlights: → Naphthopyran was first used to fabricate fluorescence switch with benzimidazole derivative. → Fluorescence intensity can be modulated by controlling the UV irradiation time. → Fluorescence intensity can be adjusted by changing the ratio of benzimidazole derivative to naphthopyran. → Decrease of fluorescence intensity is attributed to the interaction of benzimidazole derivative and naphthopyran.

  16. New photo-convertible reactions of blue-fluorescent calf α-crystallin

    International Nuclear Information System (INIS)

    Fujimori, E.

    1979-01-01

    Both native blue fluorescent α-crystalline from calf lenses and UV (300 nm)-irradiated blue-fluorescent α-crystalline, when further irradiated with 365 nm-UV light, produce photo-products capable of emitting a new fluorescence at 455 nm. Illumination of the photo-products with 420 nm visible light regenerates the original fluorescence at 420-425 nm. In addition, another fluorescence at 400 nm has also been found in UV (300 nm)-irradiated blue-fluorescent α-crystallin, when exposed to 365 nm-UV light. (author)

  17. Adoption of Light-Emitting Diodes in Common Lighting Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Mary [Navigant Consulting, Suwanee, GA (United States); Chwastyk, Dan [Navigant Consulting, Suwanee, GA (United States)

    2013-05-01

    Report estimating LED energy savings in nine applications where LEDs compete with traditional lighting sources such as incandescent, halogen, high-pressure sodium, and certain types of fluorescent. The analysis includes indoor lamp, indoor luminaire, and outdoor luminaire applications.

  18. Adoption of Light-Emitting Diodes in Common Lighting Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Mary [Navigant, Chicago, IL (United States); Stober, Kelsey [Navigant, Chicago, IL (United States)

    2015-07-01

    Report estimating LED energy savings between 2012 and 2014 in 10 applications where LEDs competed with traditional lighting sources such as incandescent, halogen, high-pressure sodium, and fluorescent. The analysis includes indoor lamp, indoor luminaire, and outdoor luminaire applications.

  19. Red and Green Fluorescence from Oral Biofilms.

    Science.gov (United States)

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

    2016-01-01

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

  20. Red and Green Fluorescence from Oral Biofilms.

    Directory of Open Access Journals (Sweden)

    Catherine M C Volgenant

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

  1. Accurate study of FosPeg® distribution in a mouse model using fluorescence imaging technique and fluorescence white monte carlo simulations

    DEFF Research Database (Denmark)

    Xie, Haiyan; Liu, Haichun; Svenmarker, Pontus

    2010-01-01

    Fluorescence imaging is used for quantitative in vivo assessment of drug concentration. Light attenuation in tissue is compensated for through Monte-Carlo simulations. The intrinsic fluorescence intensity, directly proportional to the drug concentration, could be obtained....

  2. Data collection on component malfunctions and failures of JET ICRH system

    International Nuclear Information System (INIS)

    Pinna, T.; Cambi, G.

    2007-01-01

    The objective of the activity was to collect and analyse data coming out from operating experiences gained in the Joint European Torus (JET) for the Ion Cyclotron Resonance Heating (ICRH) system in order to enrich the data collection on failures of components used in fusion facilities. Alarms/Failures and malfunctions occurred in the years of operations from March 1996 to November 2005, including information on failure modes and, where possible, causes of the failures, have been identified. Beyond information on failures and alarms events, also data related to crowbar events have been collected. About 3400 events classified as alarms or failures related to specific components or sub-systems were identified by analysing the 25 hand-written logbooks made available by the ICRH operation staff. Information about the JET pulses in which the ICRH system was operated has been extracted from the tick sheets covering the whole considered time interval. 20 hand written tick sheets cover the period from March 1996 to middle May 2003, while tick sheets recorded as excel files cover the period from May 2003 to November 2005. By analysing the tick sheets it results that the ICRH was operated during about 12000 plasma pulses. Main statistical values, such as rates of alarms/failures and corresponding standard errors and confidence intervals, have been estimated. Failure rates of systems and components have been evaluated both with regard to the ICRH operation pulses and operating days (days in which at least one ICRH module was requested to operate). Failure probabilities on demand have been evaluated with regard to number of pulses operated. Some of the results are the following: - The highest number of alarms/failures (1243) appears to be related to Erratic /No-output of the Instrumentation and Control (I and C) apparatus, followed by faults (829) of the Tetrode circuits, by faults (466) of the High Voltage Power Supply system and by faults (428) of the Tuning elements. - The

  3. Molecules for Fluorescence Detection of Specific Chemicals

    Science.gov (United States)

    Fedor, Steve

    2008-01-01

    A family of fluorescent dye molecules has been developed for use in on-off fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These compounds are amenable to fixation on or in a variety of substrates for use in fluorescence-based detection devices: they can be chemically modified to anchor them to porous or non-porous solid supports or can be incorporated into polymer films. Potential applications for these compounds include detection of chemical warfare agents, sensing of acidity or alkalinity, and fluorescent tagging of proteins in pharmaceutical research and development. These molecules could also be exploited for use as two-photon materials for photodynamic therapy in the treatment of certain cancers and other diseases. A molecule in this family consists of a fluorescent core (such as an anthracene or pyrene) attached to two end groups that, when the dye is excited by absorption of light, transfer an electron to the core, thereby quenching the fluorescence. The end groups can be engineered so that they react chemically with certain analytes. Upon reaction, electrons on the end groups are no longer available for transfer to the core and, consequently, the fluorescence from the core is no longer quenched. The chemoselectivity of these molecules can be changed by changing the end groups. For example, aniline end groups afford a capability for sensing acids or acid halides (including those contained in chemical warfare agents). Pyridine or bipyridyl end groups would enable sensing of metal ions. Other chemicals that can be selectively detected through suitable choice of end groups include glucose and proteins. Moreover, the fluorescent cores can be changed to alter light-absorption and -emission characteristics: anthracene cores fluoresce at wavelengths around 500 nm, whereas perylene cores absorb and emit at

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

    Directory of Open Access Journals (Sweden)

    Gregor P. C. Drummen

    2012-11-01

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

  5. Led induced chlorophyll fluorescence transient imager for measurements of health and stress status of whole plants

    NARCIS (Netherlands)

    Jalink, H.; Schoor, van der R.

    2011-01-01

    We have developed LED (light emitting diode) induced fluorescence transient imaging instrumentation to image the plant health/stress status by calculation of two images: Fv/Fm (variable fluorescence over saturation level of fluorescence) and the time response, tTR, of the fluorescence time curve.

  6. Office lighting systems: Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Dagnino, U. (ENEL, Milan (Italy))

    1990-09-01

    Relative to office lighting systems, in particular, those making use of tubular fluorescent lamps, currently available on the international market, this paper tries to develop lighting system, design optimization criteria. The comparative assessment of the various design possibilities considers operating cost, energy consumption, and occupational comfort/safety aspects such as lighting level uniformity and equilibrium, reduction of glare and reflection, natural/artificial lighting balance, programmed switching, computerized control systems for multi-use requirements in large areas, programmed maintenance for greater efficiency and reliability.

  7. Transient analysis of variable-speed wind turbines at wind speed disturbances and a pitch control malfunction

    International Nuclear Information System (INIS)

    Melicio, R.; Mendes, V.M.F.; Catalao, J.P.S.

    2011-01-01

    As wind power generation undergoes rapid growth, new technical challenges emerge: dynamic stability and power quality. The influence of wind speed disturbances and a pitch control malfunction on the quality of the energy injected into the electric grid is studied for variable-speed wind turbines with different power-electronic converter topologies. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with permanent magnet synchronous generators. The performance of disturbance attenuation and system robustness is ascertained. Simulation results are presented and conclusions are duly drawn.

  8. Transient analysis of variable-speed wind turbines at wind speed disturbances and a pitch control malfunction

    Energy Technology Data Exchange (ETDEWEB)

    Melicio, R. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal); Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Center for Innovation in Electrical and Energy Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

    2011-04-15

    As wind power generation undergoes rapid growth, new technical challenges emerge: dynamic stability and power quality. The influence of wind speed disturbances and a pitch control malfunction on the quality of the energy injected into the electric grid is studied for variable-speed wind turbines with different power-electronic converter topologies. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with permanent magnet synchronous generators. The performance of disturbance attenuation and system robustness is ascertained. Simulation results are presented and conclusions are duly drawn. (author)

  9. Malfunctioning and infected tunneled infusion catheters: over-the-wire catheter exchange versus catheter removal and replacement.

    Science.gov (United States)

    Guttmann, David M; Trerotola, Scott O; Clark, Timothy W; Dagli, Mandeep; Shlansky-Goldberg, Richard D; Itkin, Maxim; Soulen, Michael C; Mondschein, Jeffrey I; Stavropoulos, S William

    2011-05-01

    To compare the safety and effectiveness of over-the-wire catheter exchange (catheter-exchange) with catheter removal and replacement (removal-replacement) at a new site for infected or malfunctioning tunneled infusion catheters. Using a quality assurance database, 61 patients with tunneled infusion catheters placed during the period July 2001 to June 2009 were included in this study. Patients receiving hemodialysis catheters were excluded. Catheter-exchange was performed in 25 patients, and same-day removal-replacement was performed in 36 patients. Data collected included demographic information, indication for initial catheter placement and replacement, dwell time for the new catheter, and ultimate fate of the new device. Statistical comparisons between the two cohorts were analyzed using the Kaplan-Meier technique and Fisher exact test. Catheters exchanged over the wire remained functional without infection for a median of 102 days (range, 2-570 days), whereas catheters removed and replaced were functional for a median 238 days (range, 1-292 days, P = .12). After catheter replacement, there were 11 instances of subsequent infection in the catheter-exchange group and 7 instances in the removal-replacement cohort, accounting for infection rates of 4.4 and 2.3 per 1,000 catheter days (P = .049). Patients in the catheter-exchange group had 3.2 greater odds of infection compared with patients in the removal-replacement group. Five malfunction events occurred in each group, accounting for 2.0 and 1.7 malfunctions per 1,000 catheter days in the catheter-exchange and removal-replacement groups (P = .73). Catheter-exchange of tunneled infusion catheters results in a higher infection rate compared with removal-replacement at a new site. The rate of catheter malfunction is not significantly different between the two groups. Catheter-exchange is an alternative for patients with tunneled infusion catheters who have limited venous access, but this technique should not be

  10. Analysis of licensee event reports related to nuclear generating station onsite electrical system malfunctions, 1976-1978

    International Nuclear Information System (INIS)

    Bickel, J.H.; Abbott, E.C.

    1981-07-01

    This report summarizes the evaluation requested by the ACRS of 1177 LERS, submitted over a three year period, which related to onsite electrical system malfunctions. The evaluation was carried out for the purposes of identifying specific failure modes and consequences, evaluating the assumptions used in WASH-1400 on the reliability of electrical equipment, and identifying specific sequences which are significant to plant safety. The analysis performed provides a more specific identification of onsite electrical system failure modes, sequences, and consequences than was established in WASH-1400

  11. Photoswitchable non-fluorescent thermochromic dye-nanoparticle hybrid probes

    OpenAIRE

    Harrington, Walter N.; Haji, Mwafaq R.; Galanzha, Ekaterina I.; Nedosekin, Dmitry A.; Nima, Zeid A.; Watanabe, Fumiya; Ghosh, Anindya; Biris, Alexandru S.; Zharov, Vladimir P.

    2016-01-01

    Photoswitchable fluorescent proteins with controllable light?dark states and spectral shifts in emission in response to light have led to breakthroughs in the study of cell biology. Nevertheless, conventional photoswitching is not applicable for weakly fluorescent proteins and requires UV light with low depth penetration in bio-tissue. Here we introduce a novel concept of photoswitchable hybrid probes consisting of thermochromic dye and absorbing nanoparticles, in which temperature-sensitive ...

  12. Reproducibility and Reliability of Repeated Quantitative Fluorescence Angiography

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Knudsen, Kristine Bach Korsholm; Ambrus, Rikard

    2017-01-01

    INTRODUCTION: When using fluorescence angiography (FA) in perioperative perfusion assessment, repeated measures with re-injections of fluorescent dye (ICG) may be required. However, repeated injections may cause saturation of dye in the tissue, exceeding the limit of fluorescence intensity...... that the camera can detect. As the emission of fluorescence is dependent of the excitatory light intensity, reduction of this may solve the problem. The aim of the present study was to investigate the reproducibility and reliability of repeated quantitative FA during a reduction of excitatory light....

  13. Análise dos transientes da fluorescência da clorofila a de plantas jovens de Carapa guianensis e de Dipteryx odorata submetidas a dois ambientes de luz Analysis of chlorophyll a fluorescence transients of young plants of Carapa guianensis and Dipteryx odorata submitted to two light environments

    Directory of Open Access Journals (Sweden)

    José Francisco de Carvalho Gonçalves

    2010-03-01

    odorata (Aublet Willd exposed to two light environments (shade and sunlight. The experiment was carried in Manaus-AM, Brazil (3º8'S, 59º52'W. Analysis of chlorophyll a fluorescence transients were obtained in intact and healthy leaves between 10:00 to 12:00 am. The curve OJIP indicated that the species high irradiance exposed presented photoinhibition after 45 days of experiment. Andiroba and cumaru plants exposed to sunlight exhibited low values of TRo/ABS (7.17 and 20.4%, respectively, ETo/TRo (14.5 and 27.2%, respectively and ETo/ABS (20.6 and 42.2%, respectively and high values of DIo/ABS (26.9 and 43.0%, respectively, compared with plants exposed to the shadow with 45 days of experiment. As for phenomenological flux, most of the parameters, low values were observed for both exposed species in the sunlight. Andiroba and cumaru plants exposed in the sunlight exhibited low values of PIABS (63.3 and 78.7%, respectively compared with exposed plants to the shadow at the end of the experiment. Although the species have suffered with the stress for high irradiance andiroba specie presented better performance than cumaru being indicated for use in production planting or degraded area restoration.

  14. A study on a portable fluorescence imaging system

    Science.gov (United States)

    Chang, Han-Chao; Wu, Wen-Hong; Chang, Chun-Li; Huang, Kuo-Cheng; Chang, Chung-Hsing; Chiu, Shang-Chen

    2011-09-01

    The fluorescent reaction is that an organism or dye, excited by UV light (200-405 nm), emits a specific frequency of light; the light is usually a visible or near infrared light (405-900 nm). During the UV light irradiation, the photosensitive agent will be induced to start the photochemical reaction. In addition, the fluorescence image can be used for fluorescence diagnosis and then photodynamic therapy can be given to dental diseases and skin cancer, which has become a useful tool to provide scientific evidence in many biomedical researches. However, most of the methods on acquiring fluorescence biology traces are still stay in primitive stage, catching by naked eyes and researcher's subjective judgment. This article presents a portable camera to obtain the fluorescence image and to make up a deficit from observer competence and subjective judgment. Furthermore, the portable camera offers the 375nm UV-LED exciting light source for user to record fluorescence image and makes the recorded image become persuasive scientific evidence. In addition, when the raising the rate between signal and noise, the signal processing module will not only amplify the fluorescence signal up to 70 %, but also decrease the noise significantly from environmental light on bill and nude mouse testing.

  15. The development of the phosphors for the lighting

    OpenAIRE

    Komeno, Akira; 米野, 憲

    2006-01-01

    Phosphor materials emit various colors of lights after absorption of excitation energy such as X ray, ultraviolet light and visible light. Phosphors are important materials for displays and lighting. The roles of fluorescent lamps and displays for use as light source and color signboards have become increasingly important in daily life. In white fluorescent lamps, ultraviolet (UV: 254nm) irradiation from mercury vapor is converted into visible light by several kinds of phosphors. A salient co...

  16. Use of astronomy filters in fluorescence microscopy.

    Science.gov (United States)

    Piper, Jörg

    2012-02-01

    Monochrome astronomy filters are well suited for use as excitation or suppression filters in fluorescence microscopy. Because of their particular optical design, such filters can be combined with standard halogen light sources for excitation in many fluorescent probes. In this "low energy excitation," photobleaching (fading) or other irritations of native specimens are avoided. Photomicrographs can be taken from living motile fluorescent specimens also with a flash so that fluorescence images can be created free from indistinctness caused by movement. Special filter cubes or dichroic mirrors are not needed for our method. By use of suitable astronomy filters, fluorescence microscopy can be carried out with standard laboratory microscopes equipped with condensers for bright-field (BF) and dark-field (DF) illumination in transmitted light. In BF excitation, the background brightness can be modulated in tiny steps up to dark or black. Moreover, standard industry microscopes fitted with a vertical illuminator for examinations of opaque probes in DF or BF illumination based on incident light (wafer inspections, for instance) can also be used for excitation in epi-illumination when adequate astronomy filters are inserted as excitatory and suppression filters in the illuminating and imaging light path. In all variants, transmission bands can be modulated by transmission shift.

  17. Online Vibration Monitoring of a Water Pump Machine to Detect Its Malfunction Components Based on Artificial Neural Network

    Science.gov (United States)

    Rahmawati, P.; Prajitno, P.

    2018-04-01

    Vibration monitoring is a measurement instrument used to identify, predict, and prevent failures in machine instruments[6]. This is very needed in the industrial applications, cause any problem with the equipment or plant translates into economical loss and they are mostly monitored component off-line[2]. In this research, a system has been developed to detect the malfunction of the components of Shimizu PS-128BT water pump machine, such as capacitor, bearing and impeller by online measurements. The malfunction components are detected by taking vibration data using a Micro-Electro-Mechanical System(MEMS)-based accelerometer that are acquired by using Raspberry Pi microcomputer and then the data are converted into the form of Relative Power Ratio(RPR). In this form the signal acquired from different components conditions have different patterns. The collected RPR used as the base of classification process for recognizing the damage components of the water pump that are conducted by Artificial Neural Network(ANN). Finally, the damage test result will be sent via text message using GSM module that are connected to Raspberry Pi microcomputer. The results, with several measurement readings, with each reading in 10 minutes duration for each different component conditions, all cases yield 100% of accuracies while in the case of defective capacitor yields 90% of accuracy.

  18. Bimodal spectroscopy in elastic scattering and spatially resolved auto-fluorescence: instrumentation, light-tissues interaction modeling and application to ex vivo and in vivo biological tissues characterization for cancers detection

    International Nuclear Information System (INIS)

    Pery, Emilie

    2007-01-01

    This research activity aims at developing and validating a multimodal spectroscopy method in elastic scattering and auto-fluorescence to characterize biological tissues in vitro and in vivo. It is articulated in four axes. At first, instrumentation is considered with the development, the engineering and the experimental characterization of a fibers bimodal, multi-points spectrometry system allowing the acquisition of spectra in vivo (variable distances, fast acquisition). Secondly, the optical properties of tissues are modelled with the development and the experimental validation on phantoms of a photons propagation simulation algorithm in turbid media and multi-fluorescent. Thirdly, an experimental study has been conducted ex vivo on fresh and cryo-preserved arterial rings. It confirms the complementarity of spectroscopic measurements in elastic scattering and auto-fluorescence, and validates the method of multi-modality spectroscopy and the simulation of photons propagation algorithm. Results have well proved a correlation between rheological and optical properties. Finally, one second experimental study in vivo related to a pre-clinical tumoral model of bladder has been carried out. It highlights a significant difference in diffuse reflectance and/or auto-fluorescence and/or intrinsic fluorescence between healthy, inflammatory and tumoral tissues, on the basis of specific wavelength. The results of not supervised classification show that the combination of various spectroscopic approaches increases the reliability of the diagnosis. (author) [fr

  19. Spectroscopic investigation of Indium Bromide for lighting purposes

    NARCIS (Netherlands)

    Mulders, H.C.J.; Kroesen, G.M.W.; Haverlag, M.; Haverlag, M.; Kroesen, G.M.W.; Tagushi, T.

    2010-01-01

    Laser Induced Fluorescence was used to study the radiative properties of InBr for lighting purposes. Results include the temperature dependence of the fluorescence decay time, spectroscopic constants and rotational temperature determination from a LIF spectrum.

  20. Reviews in fluorescence 2010

    CERN Document Server

    Geddes, Chris D

    2011-01-01

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

  1. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

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

  2. An optical method for reducing green fluorescence from urine during fluorescence-guided cystoscopy

    Science.gov (United States)

    Lindvold, Lars R.; Hermann, Gregers G.

    2016-12-01

    Photodynamic diagnosis (PDD) of bladder tumour tissue significantly improves endoscopic diagnosis and treatment of bladder cancer in rigid cystoscopes in the operating theatre and thus reduces tumour recurrence. PDD comprises the use of blue light, which unfortunately excites green fluorescence from urine. As this green fluorescence confounds the desired red fluorescence of the PDD, methods for avoiding this situation particularly in cystoscopy using flexible cystoscopes are desirable. In this paper we demonstrate how a tailor made high power LED light source at 525 nm can be used for fluorescence assisted tumour detection using both a flexible and rigid cystoscope used in the outpatient department (OPD) and operating room (OR) respectively. It is demonstrated both in vitro and in vivo how this light source can significantly reduce the green fluorescence problem with urine. At the same time this light source also is useful for exciting autofluorescence in healthy bladder mucosa. This autofluorescence then provides a contrast to the sensitized fluorescence (PDD) of tumours in the bladder.

  3. Synthesis and characterization of photoswitchable fluorescent silica nanoparticles.

    Science.gov (United States)

    Fölling, Jonas; Polyakova, Svetlana; Belov, Vladimir; van Blaaderen, Alfons; Bossi, Mariano L; Hell, Stefan W

    2008-01-01

    We have designed and synthesized a new functional (amino reactive) highly efficient fluorescent molecular switch (FMS) with a photochromic diarylethene and a rhodamine fluorescent dye. The reactive group in this FMS -N-hydroxysuccinimide ester- allows selective labeling of amino containing molecules or other materials. In ethanolic solutions, the compound displays a large fluorescent quantum yield of 52 % and a large fluorescence modulation ratio (94 %) between two states that may be interconverted with red and near-UV light. Silica nanoparticles incorporating the new FMS were prepared and characterized, and their spectroscopic and switching properties were also studied. The dye retained its properties after the incorporation into the silica, thereby allowing light-induced reversible high modulation of the fluorescence signal of a single particle for up to 60 cycles, before undergoing irreversible photobleaching. Some applications of these particles in fluorescence microscopy are also demonstrated. In particular, subdiffraction images of nanoparticles were obtained, in the focal plane of a confocal microscope.

  4. Reviews in fluorescence 2008

    CERN Document Server

    Geddes, Chris D

    2010-01-01

    This volume serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence spectroscopy. It summarizes the year's progress in fluorescence and its applications as well as includes authoritative analytical reviews.

  5. Connecting active to passive fluorescence with photosynthesis: a method for evaluating remote sensing measurements of Chl fluorescence.

    Science.gov (United States)

    Magney, Troy S; Frankenberg, Christian; Fisher, Joshua B; Sun, Ying; North, Gretchen B; Davis, Thomas S; Kornfeld, Ari; Siebke, Katharina

    2017-09-01

    Recent advances in the retrieval of Chl fluorescence from space using passive methods (solar-induced Chl fluorescence, SIF) promise improved mapping of plant photosynthesis globally. However, unresolved issues related to the spatial, spectral, and temporal dynamics of vegetation fluorescence complicate our ability to interpret SIF measurements. We developed an instrument to measure leaf-level gas exchange simultaneously with pulse-amplitude modulation (PAM) and spectrally resolved fluorescence over the same field of view - allowing us to investigate the relationships between active and passive fluorescence with photosynthesis. Strongly correlated, slope-dependent relationships were observed between measured spectra across all wavelengths (F λ , 670-850 nm) and PAM fluorescence parameters under a range of actinic light intensities (steady-state fluorescence yields, F t ) and saturation pulses (maximal fluorescence yields, F m ). Our results suggest that this method can accurately reproduce the full Chl emission spectra - capturing the spectral dynamics associated with changes in the yields of fluorescence, photochemical (ΦPSII), and nonphotochemical quenching (NPQ). We discuss how this method may establish a link between photosynthetic capacity and the mechanistic drivers of wavelength-specific fluorescence emission during changes in environmental conditions (light, temperature, humidity). Our emphasis is on future research directions linking spectral fluorescence to photosynthesis, ΦPSII, and NPQ. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. Fluorescence detection of dental calculus

    International Nuclear Information System (INIS)

    Gonchukov, S; Sukhinina, A; Vdovin, Yu; Biryukova, T

    2010-01-01

    This work is devoted to the optimization of fluorescence dental calculus diagnostics in optical spectrum. The optimal wavelengths for fluorescence excitation and registration are determined. Two spectral ranges 620 – 645 nm and 340 – 370 nm are the most convenient for supra- and subgingival calculus determination. The simple implementation of differential method free from the necessity of spectrometer using was investigated. Calculus detection reliability in the case of simple implementation is higher than in the case of spectra analysis at optimal wavelengths. The use of modulated excitation light and narrowband detection of informative signal allows us to decrease essentially its diagnostic intensity even in comparison with intensity of the low level laser dental therapy

  7. Multi Spectral Fluorescence Imager (MSFI)

    Science.gov (United States)

    Caron, Allison

    2016-01-01

    Genetic transformation with in vivo reporter genes for fluorescent proteins can be performed on a variety of organisms to address fundamental biological questions. Model organisms that may utilize an ISS imager include unicellular organisms (Saccharomyces cerevisiae), plants (Arabidopsis thaliana), and invertebrates (Caenorhabditis elegans). The multispectral fluorescence imager (MSFI) will have the capability to accommodate 10 cm x 10 cm Petri plates, various sized multi-well culture plates, and other custom culture containers. Features will include programmable temperature and light cycles, ethylene scrubbing (less than 25 ppb), CO2 control (between 400 ppm and ISS-ambient levels in units of 100 ppm) and sufficient airflow to prevent condensation that would interfere with imaging.

  8. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  9. Optimization of fluorescent proteins

    NARCIS (Netherlands)

    Bindels, D.S.; Goedhart, J.; Hink, M.A.; van Weeren, L.; Joosen, L.; Gadella (jr.), T.W.J.; Engelborghs, Y.; Visser, A.J.W.G.

    2014-01-01

    Nowadays, fluorescent protein (FP) variants have been engineered to fluoresce in all different colors; to display photoswitchable, or photochromic, behavior; or to show yet other beneficial properties that enable or enhance a still growing set of new fluorescence spectroscopy and microcopy

  10. Plasmon enhanced silver quantum cluster fluorescence for biochemical applications

    DEFF Research Database (Denmark)

    Bernard, S.; Kutter, J.P.; Mogensen, Klaus Bo

    2014-01-01

    Fluorescence microscopy of individual silver quantum clusters on the surface of silver nanoparticles reveals strong photoactivated emission under blue light excitation [1-4]. In this work, silver nanoparticles are produced by annealing silver thin films deposited on a glass substrate and silver q...... purposes. It was found, that in presence of a strong nucleophile (such as CN-), silver quantum clusters are dissolved into non-fluorescing AgCN complexes, resulting in a fast and observable decrease of the fluorescent signal....

  11. Dual fluorescence of single LH2 antenna nanorings

    International Nuclear Information System (INIS)

    Freiberg, A.; Raetsep, M.; Timpmann, K.; Trinkunas, G.

    2004-01-01

    A dual nature of fluorescence from LH2 pigment-protein complexes, which is a part of the light harvesting system of purple bacteria, is confirmed by fluorescence-lifetime dependence on recording wavelength and spectrally selective spectroscopy. An analysis based on the Holstein molecular crystal model, modified by allowing diagonal disorder, suggests coexistence of large- and small-radius self-trapped excitons, which serve as the origin of the dual fluorescence

  12. Digital communication through intermolecular fluorescence modulation.

    Science.gov (United States)

    Raymo, F M; Giordani, S

    2001-06-14

    [see reaction]. Ultraminiaturized processors incorporating molecular components can be developed only after devising efficient strategies to communicate signals at the molecular level. We have demonstrated that a three-state molecular switch responds to ultraviolet light, visible light, and H+, attenuating the emission intensity of a fluorescent probe. Intermolecular communication is responsible for the transduction of three input signals into a single optical output. The behavior of the communicating ensemble of molecules corresponds to that of a logic circuit incorporating seven gates.

  13. Diversity and Ecological Correlates of Red Fluorescence in Marine Fishes

    Directory of Open Access Journals (Sweden)

    Nils Anthes

    2016-11-01

    Full Text Available Marine environments at depths below -10 to -25 m are almost devoid of ambient red sunlight because water quickly attenuates long wavelengths. This stenospectral light environment presents unique opportunities for organisms that can transform ambient blue-green light into red light by fluorescence. Numerous marine fish species display intricate patterns of fluorescence. Because color vision is a key component of fish sensory ecology, several putative visual functions of red fluorescence have been proposed but are difficult to test experimentally. Here, we follow a comparative approach to assess the consistency between the phylogenetic distribution of red fluorescence with its presumed functions. We collected and analyzed the largest data set of red fluorescence in fishes to date, consisting of confirmed cases in 272 primarily diurnal fish species from 49 out of 90 surveyed fish families and 12 out of 21 surveyed fish orders, contrasted to 393 fish species with confirmed absence of red fluorescence. Based on a priori hypotheses on adaptive function, we compare the prevalence of red fluorescence among pre-defined sets of species based on ecological or biological characteristics while controlling for shared ancestry. When comparing between species, we find no evidence that red fluorescence is more prevalent in deep-water species, contrasting with our recent finding that fluorescence brightness increases with depth within species. There is also no evidence for a role in group-driven communication. Phylogenetic patterns are consistent, however, with three other predictions. First, fluorescence with a rather patchy distribution across the body occurred significantly more often among sit-and-wait predators or otherwise sedentary fish than in more mobile species, consistent with background matching for camouflage. Second, small, predatory fishes tended to show red fluorescent irides disproportionally often consistent with a proposed function in prey

  14. Wide-field fluorescent microscopy and fluorescent imaging flow cytometry on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Ozcan, Aydogan

    2013-04-11

    Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. - 10 μm over a very large field-of-view of - 81 mm(2). This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

  15. Eosin-related fluorescence of acidophil pituitary cells

    OpenAIRE

    Friedman, H.; Friedman, I.V.C.; Mello, C.V.

    1988-01-01

    The examination of haematoxylin and eosin stained sections of normal and neoplastic pituitary glands under ultraviolet light illumination discloses fluorescence of acidophil cells. The distinction between prolactin and growth hormone-producing cells is not possible. Such fluorescence depends on previous eosin staining.

  16. Ultrafast Proton Shuttling in Psammocora Cyan Fluorescent Protein

    NARCIS (Netherlands)

    Kennis, J.T.M.; van Stokkum, I.H.M.; Peterson, D.S.; Pandit, A.; Wachter, R.M.

    2013-01-01

    Cyan, green, yellow, and red fluorescent proteins (FPs) homologous to green fluorescent protein (GFP) are used extensively as model systems to study fundamental processes in photobiology, such as the capture of light energy by protein-embedded chromophores, color tuning by the protein matrix, energy

  17. Collisional and radiative processes in fluorescent lamps

    International Nuclear Information System (INIS)

    Lister, Graeme G.

    2003-01-01

    Since electrode life is the major limiting factor in operating fluorescent lamps, many lighting companies have introduced 'electrodeless' fluorescent lamps, using inductively coupled discharges. These lamps often operate at much higher power loadings than standard lamps and numerical models have not been successful in reproducing experimental measurements in the parameter ranges of interest. A comprehensive research program was undertaken to study the fundamental physical processes of these discharges, co-funded by the Electric Power Research Institute (EPRI) and OSRAM SYLVANIA under the name of ALITE. The program included experiments and modeling of radiation transport, computations of electron-atom and atom-atom cross sections and the first comprehensive power balance studies of a highly loaded fluorescent lamp. Results from the program and their importance to the understanding of the physics of fluorescent lamps are discussed, with particular emphasis on the important collisional and radiative processes. Comparisons between results of experimental measurements and numerical models are presented

  18. Laser-induced fluorescence imaging of bacteria

    Science.gov (United States)

    Hilton, Peter J.

    1998-12-01

    This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

  19. Study of improving signal-noise ratio for fluorescence channel

    Science.gov (United States)

    Wang, Guoqing; Li, Xin; Lou, Yue; Chen, Dong; Zhao, Xin; Wang, Ran; Yan, Debao; Zhao, Qi

    2017-10-01

    Laser-induced fluorescence(LIFS), which is one of most effective discrimination methods to identify the material at the molecular level by inducing fluorescence spectrum, has been popularized for its fast and accurate probe's results. According to the research, violet laser or ultraviolet laser is always used as excitation light source. While, There is no atmospheric window for violet laser and ultraviolet laser, causing laser attenuation along its propagation path. What's worse, as the laser reaching sample, part of the light is reflected. That is, excitation laser really react on sample to produce fluorescence is very poor, leading to weak fluorescence mingled with the background light collected by LIFS' processing unit, when it used outdoor. In order to spread LIFS to remote probing under the complex background, study of improving signal-noise ratio for fluorescence channel is a meaningful work. Enhancing the fluorescence intensity and inhibiting background light both can improve fluorescence' signal-noise ratio. In this article, three different approaches of inhibiting background light are discussed to improve the signal-noise ratio of LIFS. The first method is increasing fluorescence excitation area in the proportion of LIFS' collecting field by expanding laser beam, if the collecting filed is fixed. The second one is changing field angle base to accommodate laser divergence angle. The third one is setting a very narrow gating circuit to control acquisition circuit, which is shortly open only when fluorescence arriving. At some level, these methods all can reduce the background light. But after discussion, the third one is best with adding gating acquisition circuit to acquisition circuit instead of changing light path, which is effective and economic.

  20. Construction of a bimolecular fluorescence complementation (BiFC ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-08-02

    Aug 2, 2012 ... Accepted 8 June, 2012. Protein–protein interactions are essential for signal transduction in cells. ... BiFC is a novel technology that is used for identifying .... occasional fluorescence was observed, it was very weak ... Light field.

  1. Measuring and sorting cell populations expressing isospectral fluorescent proteins with different fluorescence lifetimes.

    Directory of Open Access Journals (Sweden)

    Bryan Sands

    Full Text Available Study of signal transduction in live cells benefits from the ability to visualize and quantify light emitted by fluorescent proteins (XFPs fused to different signaling proteins. However, because cell signaling proteins are often present in small numbers, and because the XFPs themselves are poor fluorophores, the amount of emitted light, and the observable signal in these studies, is often small. An XFP's fluorescence lifetime contains additional information about the immediate environment of the fluorophore that can augment the information from its weak light signal. Here, we constructed and expressed in Saccharomyces cerevisiae variants of Teal Fluorescent Protein (TFP and Citrine that were isospectral but had shorter fluorescence lifetimes, ∼ 1.5 ns vs ∼ 3 ns. We modified microscopic and flow cytometric instruments to measure fluorescence lifetimes in live cells. We developed digital hardware and a measure of lifetime called a "pseudophasor" that we could compute quickly enough to permit sorting by lifetime in flow. We used these abilities to sort mixtures of cells expressing TFP and the short-lifetime TFP variant into subpopulations that were respectively 97% and 94% pure. This work demonstrates the feasibility of using information about fluorescence lifetime to help quantify cell signaling in living cells at the high throughput provided by flow cytometry. Moreover, it demonstrates the feasibility of isolating and recovering subpopulations of cells with different XFP lifetimes for subsequent experimentation.

  2. Fluorescent compounds for plastic scintillation applications

    International Nuclear Information System (INIS)

    Pla-Dalmau, A.; Bross, A.D.

    1994-04-01

    Several 2-(2'-hydroxyphenyl)benzothiazole, -benzoxazole, and -benzimidazole derivatives have been prepared. Transmittance, fluorescence, light yield, and decay time characteristics of these compounds have been studied in a polystyrene matrix and evaluated for use in plastic scintillation detectors. Radiation damage studies utilizing a 60 C source have also been performed

  3. Dynamic fluorescence imaging with molecular agents for cancer detection

    Science.gov (United States)

    Kwon, Sun Kuk

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

  4. Multispectral fluorescence imaging techniques for nondestructive food safety inspection

    Science.gov (United States)

    Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

    2004-03-01

    The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

  5. The camera of the Pierre Auger Observatory Fluorescence Detector

    CERN Document Server

    Ambrosio, M; Bracci, F; Facal, P; Fonte, R; Gallo, G; Kemp, E; Matthiae, Giorgio; Nicotra, D; Privitera, P; Raia, G; Tusi, E; Vitali, G

    2002-01-01

    The Fluorescence Detector of the Pierre Auger Observatory is a set of telescopes which measure the fluorescence light emitted by atmospheric nitrogen stimulated by the cosmic-ray showers. The Camera is an array of photomultipliers positioned on the telescope focal surface. We describe the main features of the camera: the hexagonal pixels geometry on the spherical focal surface; the light collectors which complement the photomultipliers; the photomultipliers test.

  6. The camera of the Pierre Auger Observatory Fluorescence Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, M.; Aramo, C.; Bracci, F.; Facal, P.; Fonte, R.; Gallo, G.; Kemp, E. E-mail: kemp@roma2.infn.it; Matthiae, G.; Nicotra, D.; Privitera, P.; Raia, G.; Tusi, E.; Vitali, G

    2002-02-01

    The Fluorescence Detector of the Pierre Auger Observatory is a set of telescopes which measure the fluorescence light emitted by atmospheric nitrogen stimulated by the cosmic-ray showers. The Camera is an array of photomultipliers positioned on the telescope focal surface. We describe the main features of the camera: the hexagonal pixels geometry on the spherical focal surface; the light collectors which complement the photomultipliers; the photomultipliers test.

  7. The camera of the Pierre Auger Observatory Fluorescence Detector

    International Nuclear Information System (INIS)

    Ambrosio, M.; Aramo, C.; Bracci, F.; Facal, P.; Fonte, R.; Gallo, G.; Kemp, E.; Matthiae, G.; Nicotra, D.; Privitera, P.; Raia, G.; Tusi, E.; Vitali, G.

    2002-01-01

    The Fluorescence Detector of the Pierre Auger Observatory is a set of telescopes which measure the fluorescence light emitted by atmospheric nitrogen stimulated by the cosmic-ray showers. The Camera is an array of photomultipliers positioned on the telescope focal surface. We describe the main features of the camera: the hexagonal pixels geometry on the spherical focal surface; the light collectors which complement the photomultipliers; the photomultipliers test

  8. An electronically tunable ultrafast laser source applied to fluorescence imaging and fluorescence lifetime imaging microscopy

    International Nuclear Information System (INIS)

    Dunsby, C; Lanigan, P M P; McGinty, J; Elson, D S; Requejo-Isidro, J; Munro, I; Galletly, N; McCann, F; Treanor, B; Oenfelt, B; Davis, D M; Neil, M A A; French, P M W

    2004-01-01

    Fluorescence imaging is used widely in microscopy and macroscopic imaging applications for fields ranging from biomedicine to materials science. A critical component for any fluorescence imaging system is the excitation source. Traditionally, wide-field systems use filtered thermal or arc-generated white light sources, while point scanning confocal microscope systems require spatially coherent (point-like) laser sources. Unfortunately, the limited range of visible wavelengths available from conventional laser sources constrains the design and usefulness of fluorescent probes in confocal microscopy. A 'hands-off' laser-like source, electronically tunable across the visible spectrum, would be invaluable for fluorescence imaging and provide new opportunities, e.g. automated excitation fingerprinting and in situ measurement of excitation cross-sections. Yet more information can be obtained using fluorescence lifetime imaging (FLIM), which requires that the light source be pulsed or rapidly modulated. We show how a white light continuum, generated by injecting femtosecond optical radiation into a micro-structured optical fibre, coupled with a simple prism-based tunable filter arrangement, can fulfil all these roles as a continuously electronically tunable (435-1150 nm) visible ultrafast light source in confocal, wide-field and FLIM systems

  9. Heat transfer assembly for a fluorescent lamp and fixture

    Science.gov (United States)

    Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

    1992-12-29

    In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

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

    Science.gov (United States)

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

    2011-06-01

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

  11. Mitochondrial Malfunctioning, Proteasome Arrest and Apoptosis in Cancer Cells by Focused Intracellular Generation of Oxygen Radicals

    Directory of Open Access Journals (Sweden)

    Ilaria Postiglione

    2015-08-01

    Full Text Available Photofrin/photodynamic therapy (PDT at sub-lethal doses induced a transient stall in proteasome activity in surviving A549 (p53+/+ and H1299 (p53−/− cells as indicated by the time-dependent decline/recovery of chymotrypsin-like activity. Indeed, within 3 h of incubation, Photofrin invaded the cytoplasm and localized preferentially within the mitochondria. Its light activation determined a decrease in mitochondrial membrane potential and a reversible arrest in proteasomal activity. A similar result is obtained by treating cells with Antimycin and Rotenone, indicating, as a common denominator of this effect, the ATP decrease. Both inhibitors, however, were more toxic to cells as the recovery of proteasomal activity was incomplete. We evaluated whether combining PDT (which is a treatment for killing tumor cells, per se, and inducing proteasome arrest in the surviving ones with Bortezomib doses capable of sustaining the stall would protract the arrest with sufficient time to induce apoptosis in remaining cells. The evaluation of the mitochondrial membrane depolarization, residual proteasome and mitochondrial enzymatic activities, colony-forming capabilities, and changes in protein expression profiles in A549 and H1299 cells under a combined therapeutic regimen gave results consistent with our hypothesis.

  12. The predictive value of the radionuclide fistulogram (RnF) and its perioperative evaluation in arterio-venous fistulae (AVf) malfunction

    Energy Technology Data Exchange (ETDEWEB)

    Seo, I.S.; Sy, W.M.; Heneghan, W.; Manoli, A.

    1985-05-01

    The predictive value of the RnF in AVf malfunction was determined in 56 hemodialysis patients (77 studies). Two second dynamic images (qualitative) and concurrent 64 x 64 byte mode acquisition with .5 sec/frame for 1 min. (quantitative) were obtained following the administration of 15-20 mCi of Tc99m compounds (MDP or Tc04) into or near the AVf. Fourteen patients with clinical suspicion of AVf malfunction were referred for RnF. Eleven (78.6%) were abnormal and 3 were normal, based on previously established qualitative (collaterals, back flow and/or stenosis) and quantitative (S/sub 1//S/sub 2/<10%) criteria. Confirmatory contrast fistulogram (CnF) and surgical repair were done in 8/11. In three with normal studies, one had soft tissue abscesses near the venous orifice, another was attributed to malposition of needles at hemodialysis and no cause was apparent in the third. In 42 clinically unsuspected patients who were referred for other studies (bone scintigraphy and MUGA), nine (21.9%) had abnormal findings. Within three months, surgical repairs were made in four after CnF's confirmed AVf malfunction. The remaining five later developed signs of malfunction. 9 of 12 patients with surgical repairs had post surgical studies: 5 were normal while 2 remained abnormal even after a second surgical attempt; 2 had no follow up studies but were clinically asymptomatic. RnF is a simple benign imaging procedure with a high predictive value in documenting AVf malfunction in both symptomatic (78.9%) and in otherwise clinically unsuspected (21.9%) patients. Excellent clinical correlation in patients with surgical repairs is achieved.

  13. Effects of read-out light sources and ambient light on radiochromic film

    International Nuclear Information System (INIS)

    Butson, Martin J.; Yu, Peter K.N.; Metcalfe, Peter E.

    1998-01-01

    Both read-out light sources and ambient light sources can produce a marked effect on coloration of radiochromic film. Fluorescent, helium neon laser, light emitting diode (LED) and incandescent read-out light sources produce an equivalent dose coloration of 660 cGy h -1 , 4.3 cGy h -1 , 1.7 cGy h -1 and 2.6 cGy h -1 respectively. Direct sunlight, fluorescent light and incandescent ambient light produce an equivalent dose coloration of 30 cGy h -1 , 18 cGy h -1 and 0 cGy h -1 respectively. Continuously on, fluorescent light sources should not be used for film optical density evaluation and minimal exposure to any light source will increase the accuracy of results. (author)

  14. Advanced lighting guidelines: 1993. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Eley, C.; Tolen, T.M. [Eley Associates, San Francisco, CA (United States); Benya, J.R. [Luminae Souter Lighting Design, San Francisco, CA (United States); Rubinstein, F.; Verderber, R. [Lawrence Berkeley Lab., CA (United States)

    1993-12-31

    The 1993 Advanced Lighting Guidelines document consists of twelve guidelines that provide an overview of specific lighting technologies and design application techniques utilizing energy-efficient lighting practice. Lighting Design Practice assesses energy-efficient lighting strategies, discusses lighting issues, and explains how to obtain quality lighting design and consulting services. Luminaires and Lighting Systems surveys luminaire equipment designed to take advantage of advanced technology lamp products and includes performance tables that allow for accurate estimation of luminaire light output and power input. The additional ten guidelines -- Computer-Aided Lighting Design, Energy-Efficient Fluorescent Ballasts, Full-Size Fluorescent Lamps, Compact Fluorescent Lamps, Tungsten-Halogen Lamps, Metal Halide and HPS Lamps, Daylighting and Lumen Maintenance, Occupant Sensors, Time Scheduling Systems, and Retrofit Control Technologies -- each provide a product technology overview, discuss current products on the lighting equipment market, and provide application techniques. This document is intended for use by electric utility personnel involved in lighting programs, lighting designers, electrical engineers, architects, lighting manufacturers` representatives, and other lighting professionals.

  15. Fluorescent optical liquid-level sensor

    International Nuclear Information System (INIS)

    Weiss, Jonathan D.

    2000-01-01

    An optical method of detecting a liquid level is presented that uses fluorescence radiation generated in an impurity-doped glass or plastic slab. In operation, the slab is inserted into the liquid and pump light is coupled into it so that the light is guided by the slab-air interface above the liquid and escapes into the liquid just below its surface. Since the fluorescence is generated only in that section of the slab above the liquid, the fluorescence power will monotonically decrease with increasing liquid level. Thus, a relationship can be established between any signal proportional to it and the liquid level. Because optical fibers link the pump source and the detector of fluorescence radiation to the sensor, no electrical connections are needed in or near the liquid. Their absence vastly decreases the hazard associated with placing a liquid-level sensor in a potentially explosive environment. A laboratory prototype, consisting of a methyl styrene slab doped with an organic dye, has been built and successfully tested in water. Its response to liquid level when pumped by a tunable argon-ion laser at 476, 488, and 496 nm, and by a blue LED, is presented and shown to be consistent with theory. The fluorescence spectra, optical efficiency, temperature, and other effects are also presented and discussed. (c) 2000 Society of Photo-Optical Instrumentation Engineers

  16. Upconverting fluorescent nanoparticles for biodetection and photoactivation

    Science.gov (United States)

    Huang, Kai; Li, WenKai; Jayakumar, Muthu Kumara Gnanasammandhan; Zhang, Yong

    2013-03-01

    Fluorophores including fluorescent dyes/proteins and quantum dots (QDs) are used for fluorescence-based imaging and detection. These are based on `downconversion fluorescence' and have several drawbacks: photobleaching, autofluorescence, short tissue penetration depth and tissue photo-damage. Upconversion fluorescent nanoparticles (UCNs) emit detectable photons of higher energy in the short wavelength range upon irradiation with near-infrared (NIR) light based on a process termed `upconversion'. UCNs show absolute photostability, negligible autofluorescence, high penetration depth and minimum photodamage to biological tissues. Lanthanide doped nanocrystals with nearinfrared NIR-to-NIR and/or NIR-to-VIS and/or NIR-to-UV upconversion fluorescence emission have been synthesized. The nanocrystals with small size and tunable multi-color emission have been developed. The emission can be tuned by doping different upconverting lanthanide ions into the nanocrystals. The nanocrystals with core-shell structure have also been prepared to tune the emission color. The surfaces of these nanocrystals have been modified to render them water dispersible and biocompatible. They can be used for ultrasensitive interference-free biodetection because most biomolecules do not have upconversion properties. UCNs are also useful for light based therapy with enhanced efficiency, for example, photoactivation.

  17. 76 FR 70547 - Energy Conservation Program: Energy Conservation Standards for Fluorescent Lamp Ballasts

    Science.gov (United States)

    2011-11-14

    ... the term ``fluorescent lamp,'' which EPCA defines as ``a low pressure mercury electric-discharge... discharge into light,'' and as including the four enumerated types of fluorescent lamps for which EPCA... Conservation Program: Energy Conservation Standards for Fluorescent Lamp Ballasts; Final Rule #0;#0;Federal...

  18. A simple optical fiber device for quantitative fluorescence microscopy of single living cells

    NARCIS (Netherlands)

    van Graft, M.; van Graft, Marja; Oosterhuis, B.; Oosterhuis, Bernard; van der Werf, Kees; de Grooth, B.G.; Greve, Jan

    1993-01-01

    simple and relatively inexpensive system is described for obtaining quantitative fluorescence measurements on single living cells loaded with a fluorescent probe to study cell physiological processes. The light emitted from the fluorescent cells is captured by and transported through an optical

  19. Satellite-detected fluorescence reveals global physiology of ocean phytoplankton

    Directory of Open Access Journals (Sweden)

    M. J. Behrenfeld

    2009-05-01

    Full Text Available Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.

  20. Fluorescence spectral properties of stomach tissues with pathology

    Science.gov (United States)

    Giraev, K. M.; Ashurbekov, N. A.; Lahina, M. A.

    2012-05-01

    Steady-state fluorescence and diffuse reflection spectra are measured for in vivo normal and pathological (chronic atrophic and ulcerating defects, malignant neoplasms) stomach mucous lining tissues. The degree of distortion of the fluorescence spectra is estimated taking light scattering and absorption into account. A combination of Gauss and Lorentz functions is used to decompose the fluorescence spectra. Potential groups of fluorophores are determined and indices are introduced to characterize the dynamics of their contributions to the resultant spectra as pathologies develop. Reabsorption is found to quench the fluorescence of structural proteins by as much as a factor of 3, while scattering of the light can increase the fluorescence intensity of flavin and prophyrin groups by as much as a factor of 2.