Toward enhancing the distributed video coder under a multiview video codec framework

Science.gov (United States)

Lee, Shih-Chieh; Chen, Jiann-Jone; Tsai, Yao-Hong; Chen, Chin-Hua

2016-11-01

The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

Nanogap embedded silver gratings for surface plasmon enhanced fluorescence

Science.gov (United States)

Bhatnagar, Kunal

Plasmonic nanostructures have been extensively used in the past few decades for applications in sub-wavelength optics, data storage, optoelectronic circuits, microscopy and bio-photonics. The enhanced electromagnetic field produced at the metal and dielectric interface by the excitation of surface plasmons via incident radiation can be used for signal enhancement in fluorescence and surface enhanced Raman scattering studies. Novel plasmonic structures have shown to provide very efficient and extreme light concentration at the nano-scale in recent years. The enhanced electric field produced within a few hundred nanometers of these surfaces can be used to excite fluorophores in the surrounding environment. Fluorescence based bio-detection and bio-imaging are two of the most important tools in the life sciences and improving the qualities and capabilities of fluorescence based detectors and imaging equipment remains a big challenge for industry manufacturers. We report a novel fabrication technique for producing nano-gap embedded periodic grating substrates on the nanoscale using a store bought HD-DVD and conventional soft lithography procedures. Polymethylsilsesquioxane (PMSSQ) polymer is used as the ink for the micro-contact printing process with PDMS stamps obtained from the inexpensive HD-DVDs as master molds. Fluorescence enhancement factors of up to 118 times were observed with these silver nanostructures in conjugation with Rhodamine-590 fluorescent dye. These substrates are ideal candidates for a robust and inexpensive optical system with applications such as low-level fluorescence based analyte detection, single molecule imaging, and surface enhanced Raman studies. Preliminary results in single molecule experiments have also been obtained by imaging individual 3 nm and 20 nm dye-doped nanoparticles attached to the silver plasmonic gratings using epi-fluorescence microscopy.

Fluorescence enhancement of modified silver nanoparticles.

Science.gov (United States)

Liu, Meicen; Zhang, Zhenglong; Liu, Gaining; Dong, Jun; Sun, Yu; Zheng, Hairong; Li, Guian

2011-11-01

Surface enhanced fluorescence (SEF) effect of acridine orange fluorophore in the proximity of silver nanoparticles (NPs) has been investigated experimentally in the aqueous solution system. It was found that the SEF effect could be influenced by the distribution of the NPs and the separation between the fluorophore molecule and metal surface. The fluorescence enhancement was improved significantly when Ag NPs was capped with 4-Aminothiophenol (PATP) that was acted as an isolating layer between the metal surface and fluorophore molecules. The results suggest that a proper distribution of metallic NPs and proper separation between fluorophore molecule and the particle surface are important for obtaining an optimal SEF effect.

Solvent-dependent fluorescence enhancement and piezochromism of a carbazole-substituted naphthopyran

Energy Technology Data Exchange (ETDEWEB)

Liu, Lihui; Wang, Aixia [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Wang, Guang, E-mail: wangg923@nenu.edu.cn [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Munyentwari, Alexis [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Zhou, Yihan, E-mail: yhzhou@ciac.ac.cn [National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2015-09-15

A novel carbazole-substituted naphthopyran, 3,3-bis-(4-carbazolylphenyl)-[3H]-naphtho[2,1-b]pyran (CzNP) was designed and synthesized. The new compound exhibited normal photochromism in dichloromethane solution and the UV irradiation did not influence its fluorescence. On the contrary, the fluorescence of CzNP in N,N-dimethylformamide (DMF) was intensively enhanced to 29 times after 60 min of the UV irradiation and this enhanced fluorescence can be quenched by addition of triethylamine (TEA). The study of enhanced extent of fluorescence of CzNP in solvents with different polarities and in mixed solvents demonstrated that the enhanced fluorescence is dependent on the polarity of solvents. The larger the polarity of solvent was, the stronger was the fluorescence of CzNP. CzNP also exhibited piezochromic performance and the pressure led to the cleavage of the C–O bond of pyran ring. - Highlights: • A carbazole-substituted photochromic naphthopyran was designed and synthesized. • The fluorescence was enhanced under the existence of DMF and UV irradiation. • The polarity of solvent was the dominating factor to affect the fluorescence. • The new compound also displayed piezochromic performance.

Experimental assessment of fluorescence microscopy signal enhancement by stimulated emission

Science.gov (United States)

Dake, Fumihiro; Yazawa, Hiroki

2017-10-01

The quantity of photons generated during fluorescence microscopy is principally determined by the quantum yield of the fluorescence dyes and the optical power of the excitation beam. However, even though low quantum yields can produce poor images, it is challenging to tune this parameter, while increasing the power of the excitation beam often results in photodamage. Here, we propose the use of stimulated emission (SE) as a means of enhancing both the signal intensity and signal-to-noise ratio during confocal fluorescence microscopy. This work experimentally confirmed that both these factors can be enhanced by SE radiation, through generating a greater number of photons than are associated with the standard fluorescence signal. We also propose the concept of stimulated emission enhancing fluorescence (SEEF) microscopy, which employs both the SE and fluorescence signals, and demonstrate that the intensity of an SEEF signal is greater than those of the individual SE and fluorescence signals.

Plasma characterization using terahertz-wave-enhanced fluorescence

International Nuclear Information System (INIS)

Liu Jingle; Zhang, X.-C.

2010-01-01

We demonstrate that the terahertz-wave-enhanced fluorescence emission from excited atoms or molecules can be employed in the characterization of laser-induced gas plasmas. The electron relaxation time and plasma density were deduced through applying the electron impact excitation/ionization and electron-ion recombination processes to the measured time-dependent enhanced fluorescence. The electron collision dynamics of nitrogen plasma excited at different gas pressures and laser pulse energies have been systematically investigated. This plasma characterization method provides picosecond temporal resolution and enables omnidirectional optical signal collection.

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.

Terahertz-Radiation-Enhanced Emission of Fluorescence from Gas Plasma

International Nuclear Information System (INIS)

Liu Jingle; Zhang, X.-C.

2009-01-01

We report the study of femtosecond laser-induced air plasma fluorescence under the illumination of terahertz (THz) pulses. Semiclassical modeling and experimental verification indicate that time-resolved THz radiation-enhanced emission of fluorescence is dominated by the electron kinetics and the electron-impact excitation of gas molecules or ions. We demonstrate that the temporal waveform of the THz field could be retrieved from the transient enhanced fluorescence, making omnidirectional, coherent detection available for THz time-domain spectroscopy.

Nano-Gap Embedded Plasmonic Gratings for Surface Plasmon Enhanced Fluorescence

Science.gov (United States)

Bhatnagar, Kunal; Bok, Sangho; Korampally, Venumadhav; Gangopadhyay, Shubhra

2012-02-01

Plasmonic nanostructures have been extensively used in the past few decades for applications in sub-wavelength optics, data storage, optoelectronic circuits, microscopy and bio-photonics. The enhanced electromagnetic field produced at the metal/dielectric interface by the excitation of surface plasmons via incident radiation can be used for signal enhancement in fluorescence and surface enhanced Raman scattering studies. Novel plasmonic structures on the sub wavelength scale have been shown to provide very efficient and extreme light concentration at the nano-scale. The enhanced electric field produced within a few hundred nanometers of these structures can be used to excite fluorophores in the surrounding environment. Fluorescence based bio-detection and bio-imaging are two of the most important tools in the life sciences. Improving the qualities and capabilities of fluorescence based detectors and imaging equipment has been a big challenge to the industry manufacturers. We report the novel fabrication of nano-gap embedded periodic grating substrates on the nanoscale using micro-contact printing and polymethylsilsesquioxane (PMSSQ) polymer. Fluorescence enhancement of up to 118 times was observed with these silver nanostructures in conjugation with Rhodamine-590 fluorescent dye. These substrates are ideal candidates for low-level fluorescence detection and single molecule imaging.

Quantitative fluorescence angiography for neurosurgical interventions.

Science.gov (United States)

Weichelt, Claudia; Duscha, Philipp; Steinmeier, Ralf; Meyer, Tobias; Kuß, Julia; Cimalla, Peter; Kirsch, Matthias; Sobottka, Stephan B; Koch, Edmund; Schackert, Gabriele; Morgenstern, Ute

2013-06-01

Present methods for quantitative measurement of cerebral perfusion during neurosurgical operations require additional technology for measurement, data acquisition, and processing. This study used conventional fluorescence video angiography--as an established method to visualize blood flow in brain vessels--enhanced by a quantifying perfusion software tool. For these purposes, the fluorescence dye indocyanine green is given intravenously, and after activation by a near-infrared light source the fluorescence signal is recorded. Video data are analyzed by software algorithms to allow quantification of the blood flow. Additionally, perfusion is measured intraoperatively by a reference system. Furthermore, comparing reference measurements using a flow phantom were performed to verify the quantitative blood flow results of the software and to validate the software algorithm. Analysis of intraoperative video data provides characteristic biological parameters. These parameters were implemented in the special flow phantom for experimental validation of the developed software algorithms. Furthermore, various factors that influence the determination of perfusion parameters were analyzed by means of mathematical simulation. Comparing patient measurement, phantom experiment, and computer simulation under certain conditions (variable frame rate, vessel diameter, etc.), the results of the software algorithms are within the range of parameter accuracy of the reference methods. Therefore, the software algorithm for calculating cortical perfusion parameters from video data presents a helpful intraoperative tool without complex additional measurement technology.

Improving human object recognition performance using video enhancement techniques

Science.gov (United States)

Whitman, Lucy S.; Lewis, Colin; Oakley, John P.

2004-12-01

Atmospheric scattering causes significant degradation in the quality of video images, particularly when imaging over long distances. The principle problem is the reduction in contrast due to scattered light. It is known that when the scattering particles are not too large compared with the imaging wavelength (i.e. Mie scattering) then high spatial resolution information may be contained within a low-contrast image. Unfortunately this information is not easily perceived by a human observer, particularly when using a standard video monitor. A secondary problem is the difficulty of achieving a sharp focus since automatic focus techniques tend to fail in such conditions. Recently several commercial colour video processing systems have become available. These systems use various techniques to improve image quality in low contrast conditions whilst retaining colour content. These systems produce improvements in subjective image quality in some situations, particularly in conditions of haze and light fog. There is also some evidence that video enhancement leads to improved ATR performance when used as a pre-processing stage. Psychological literature indicates that low contrast levels generally lead to a reduction in the performance of human observers in carrying out simple visual tasks. The aim of this paper is to present the results of an empirical study on object recognition in adverse viewing conditions. The chosen visual task was vehicle number plate recognition at long ranges (500 m and beyond). Two different commercial video enhancement systems are evaluated using the same protocol. The results show an increase in effective range with some differences between the different enhancement systems.

Enhanced 3D fluorescence live cell imaging on nanoplasmonic substrate

International Nuclear Information System (INIS)

Gartia, Manas Ranjan; Hsiao, Austin; Logan Liu, G; Sivaguru, Mayandi; Chen Yi

2011-01-01

We have created a randomly distributed nanocone substrate on silicon coated with silver for surface-plasmon-enhanced fluorescence detection and 3D cell imaging. Optical characterization of the nanocone substrate showed it can support several plasmonic modes (in the 300-800 nm wavelength range) that can be coupled to a fluorophore on the surface of the substrate, which gives rise to the enhanced fluorescence. Spectral analysis suggests that a nanocone substrate can create more excitons and shorter lifetime in the model fluorophore Rhodamine 6G (R6G) due to plasmon resonance energy transfer from the nanocone substrate to the nearby fluorophore. We observed three-dimensional fluorescence enhancement on our substrate shown from the confocal fluorescence imaging of chinese hamster ovary (CHO) cells grown on the substrate. The fluorescence intensity from the fluorophores bound on the cell membrane was amplified more than 100-fold as compared to that on a glass substrate. We believe that strong scattering within the nanostructured area coupled with random scattering inside the cell resulted in the observed three-dimensional enhancement in fluorescence with higher photostability on the substrate surface.

Enhanced 3D fluorescence live cell imaging on nanoplasmonic substrate

Energy Technology Data Exchange (ETDEWEB)

Gartia, Manas Ranjan [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana, IL 61801 (United States); Hsiao, Austin; Logan Liu, G [Department of Bioengineering, University of Illinois, Urbana, IL 61801 (United States); Sivaguru, Mayandi [Institute for Genomic Biology, University of Illinois, Urbana, IL 61801 (United States); Chen Yi, E-mail: loganliu@illinois.edu [Department of Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801 (United States)

2011-09-07

We have created a randomly distributed nanocone substrate on silicon coated with silver for surface-plasmon-enhanced fluorescence detection and 3D cell imaging. Optical characterization of the nanocone substrate showed it can support several plasmonic modes (in the 300-800 nm wavelength range) that can be coupled to a fluorophore on the surface of the substrate, which gives rise to the enhanced fluorescence. Spectral analysis suggests that a nanocone substrate can create more excitons and shorter lifetime in the model fluorophore Rhodamine 6G (R6G) due to plasmon resonance energy transfer from the nanocone substrate to the nearby fluorophore. We observed three-dimensional fluorescence enhancement on our substrate shown from the confocal fluorescence imaging of chinese hamster ovary (CHO) cells grown on the substrate. The fluorescence intensity from the fluorophores bound on the cell membrane was amplified more than 100-fold as compared to that on a glass substrate. We believe that strong scattering within the nanostructured area coupled with random scattering inside the cell resulted in the observed three-dimensional enhancement in fluorescence with higher photostability on the substrate surface.

Do enhanced states exist? Boosting cognitive capacities through an action video-game.

Science.gov (United States)

Kozhevnikov, Maria; Li, Yahui; Wong, Sabrina; Obana, Takashi; Amihai, Ido

2018-04-01

This research reports the existence of enhanced cognitive states in which dramatic temporary improvements in temporal and spatial aspects of attention were exhibited by participants who played (but not by those who merely observed) action video-games meeting certain criteria. Specifically, Experiments 1 and 2 demonstrate that the attentional improvements were exhibited only by participants whose skills matched the difficulty level of the video game. Experiment 2 showed that arousal (as reflected by the reduction in parasympathetic activity and increase in sympathetic activity) is a critical physiological condition for enhanced cognitive states and corresponding attentional enhancements. Experiment 3 showed that the cognitive enhancements were transient, and were no longer observed after 30 min of rest following video-gaming. Moreover, the results suggest that the enhancements were specific to tasks requiring visual-spatial focused attention, but not distribution of spatial attention as has been reported to improve significantly and durably as a result of long-term video-game playing. Overall, the results suggest that the observed enhancements cannot be simply due to the activity of video-gaming per se, but might rather represent an enhanced cognitive state resulting from specific conditions (heightened arousal in combination with active engagement and optimal challenge), resonant with what has been described in previous phenomenological literature as "flow" (Csikszentmihalyi, 1975) or "peak experiences" (Maslov, 1962). The findings provide empirical evidence for the existence of the enhanced cognitive states and suggest possibilities for consciously accessing latent resources of our brain to temporarily boost our cognitive capacities upon demand. Copyright © 2018 Elsevier B.V. All rights reserved.

Plasmon-enhanced fluorescence near nonlocal metallic nanospheres

DEFF Research Database (Denmark)

Tserkezis, Christos; Stefanou, N.; Wubs, Martijn

Spontaneous emission and fluorescence of organic molecules are known to strongly depend on the local electromagnetic environment. Plasmonic nanoparticles are widely explored as templates for controlling light-matter interactions, and can be tailored to optimize the fluorescence rate (Ȗem......) and the generalized nonlocal optical response (GNOR) theory [2] shows that a significant decrease in fluorescence enhancement is obtained for emitters close to small metallic nanospheres or thin metallic nanoshells, while the optimum emitter position is also affected. In this respect, our recent work introduces...

Riboflavin enhanced fluorescence of highly reduced graphene oxide

Science.gov (United States)

Iliut, Maria; Gabudean, Ana-Maria; Leordean, Cosmin; Simon, Timea; Teodorescu, Cristian-Mihail; Astilean, Simion

2013-10-01

The improvement of graphene derivates' fluorescence properties is a challenging topic and very few ways were reported up to now. In this Letter we propose an easy method to enhance the fluorescence of highly reduced graphene oxide (rGO) through non-covalent binding to a molecular fluorophore, namely the riboflavin (Rb). While the fluorescence of Rb is quenched, the Rb - decorated rGO exhibits strong blue fluorescence and significantly increased fluorescence lifetime, as compared to its pristine form. The data reported here represent a promising start towards tailoring the optical properties of rGOs, having utmost importance in optical applications.

Highly sensitive C-reactive protein (CRP) assay using metal-enhanced fluorescence (MEF)

International Nuclear Information System (INIS)

Zhang, Yi; Keegan, Gemma L.; Stranik, Ondrej; Brennan-Fournet, Margaret E.; McDonagh, Colette

2015-01-01

Fluorescence has been extensively employed in the area of diagnostic immunoassays. A significant enhancement of fluorescence can be achieved when noble metal nanoparticles are placed in close proximity to fluorophores. This effect, referred to as metal-enhanced fluorescence (MEF), has the potential to produce immunoassays with a high sensitivity and a low limit of detection (LOD). In this study, we investigate the fluorescence enhancement effect of two different nanoparticle systems, large spherical silver nanoparticles (AgNPs) and gold edge-coated triangular silver nanoplates, and both systems were evaluated for MEF. The extinction properties and electric field enhancement of both systems were modeled, and the optimum system, spherical AgNPs, was used in a sandwich immunoassay for human C-reactive protein with a red fluorescent dye label. A significant enhancement in the fluorescence was observed, which corresponded to an LOD improvement of ∼19-fold compared to a control assay without AgNPs

Highly sensitive C-reactive protein (CRP) assay using metal-enhanced fluorescence (MEF)

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yi; Keegan, Gemma L., E-mail: gemmakeegan@gmail.com [Dublin City University, School of Physical Sciences, Biomedical Diagnostics Institute (Ireland); Stranik, Ondrej [Leibniz Institute of Photonic Technology, Department of NanoBiophotonics (Germany); Brennan-Fournet, Margaret E. [CMP-EMSE, MOC, Department of Bioelectronics, Ecole Nationale Superieure des Mines (France); McDonagh, Colette [Dublin City University, School of Physical Sciences, Biomedical Diagnostics Institute (Ireland)

2015-07-15

Fluorescence has been extensively employed in the area of diagnostic immunoassays. A significant enhancement of fluorescence can be achieved when noble metal nanoparticles are placed in close proximity to fluorophores. This effect, referred to as metal-enhanced fluorescence (MEF), has the potential to produce immunoassays with a high sensitivity and a low limit of detection (LOD). In this study, we investigate the fluorescence enhancement effect of two different nanoparticle systems, large spherical silver nanoparticles (AgNPs) and gold edge-coated triangular silver nanoplates, and both systems were evaluated for MEF. The extinction properties and electric field enhancement of both systems were modeled, and the optimum system, spherical AgNPs, was used in a sandwich immunoassay for human C-reactive protein with a red fluorescent dye label. A significant enhancement in the fluorescence was observed, which corresponded to an LOD improvement of ∼19-fold compared to a control assay without AgNPs.

Surface plasmon-enhanced molecular fluorescence induced by gold nanostructures

International Nuclear Information System (INIS)

Teng, Y.; Ueno, K.; Shi, X.; Aoyo, D.; Misawa, H.; Qiu, J.

2012-01-01

The authors report on surface plasmon-enhanced fluorescence of Eosin Y molecules induced by gold nanostructures. Al 2 O 3 films deposited by atomic layer deposition with sub-nanometer resolution were used as the spacer layer to control the distance between molecules and the gold surface. As the thickness of the Al 2 O 3 film increased, the fluorescence intensity first increased and then decreased. The highest enhancement factor is achieved with a 1 nm Al 2 O 3 film. However, the trend for the fluorescence lifetime is the opposite. It first decreased and then increased. The changes in the fluorescence quantum yield were also calculated. The yield shows a similar trend to the fluorescence intensity. The competition between the surface plasmon-induced increase in the radiative decay rate and the gold-induced fluorescence quenching is responsible for the observed phenomenon. In addition, this competition strongly depends on the thickness of the spacer layer between Eosin Y molecules and the gold surface. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Prior video game exposure does not enhance robotic surgical performance.

Science.gov (United States)

Harper, Jonathan D; Kaiser, Stefan; Ebrahimi, Kamyar; Lamberton, Gregory R; Hadley, H Roger; Ruckle, Herbert C; Baldwin, D Duane

2007-10-01

Prior research has demonstrated that counterintuitive laparoscopic surgical skills are enhanced by experience with video games. A similar relation with robotic surgical skills has not been tested. The purpose of this study was to determine whether prior video-game experience enhances the acquisition of robotic surgical skills. A series of 242 preclinical medical students completed a self-reported video-game questionnaire detailing the frequency, duration, and peak playing time. The 10 students with the highest and lowest video-game exposure completed a follow-up questionnaire further quantifying video game, sports, musical instrument, and craft and hobby exposure. Each subject viewed a training video demonstrating the use of the da Vinci surgical robot in tying knots, followed by 3 minutes of proctored practice time. Subjects then tied knots for 5 minutes while an independent blinded observer recorded the number of knots tied, missed knots, frayed sutures, broken sutures, and mechanical errors. The mean playing time for the 10 game players was 15,136 total hours (range 5,840-30,000 hours). Video-game players tied fewer knots than nonplayers (5.8 v 9.0; P = 0.04). Subjects who had played sports for at least 4 years had fewer mechanical errors (P = 0.04), broke fewer sutures (P = 0.01), and committed fewer total errors (P = 0.01). Similarly, those playing musical instruments longer than 5 years missed fewer knots (P = 0.05). In the extremes of video-game experience tested in this study, game playing was inversely correlated with the ability to learn robotic suturing. This study suggests that advanced surgical skills such as robotic suturing may be learned more quickly by athletes and musicians. Prior extensive video-game exposure had a negative impact on robotic performance.

Concentration Dependence of Gold Nanoparticles for Fluorescence Enhancement

Science.gov (United States)

Solomon, Joel; Wittmershaus, Bruce

Noble metal nanoparticles possess a unique property known as surface plasmon resonance in which the conduction electrons oscillate due to incoming light, dramatically increasing their absorption and scattering of light. The oscillating electrons create a varying electric field that can affect nearby molecules. The fluorescence and photostability of fluorophores can be enhanced significantly when they are near plasmonic nanoparticles. This effect is called metal enhanced fluorescence (MEF). MEF from two fluorescence organic dyes, Lucifer Yellow CH and Riboflavin, was measured with different concentrations of 50-nm colloidal gold nanoparticles (Au-NP). The concentration range of Au-NP was varied from 2.5 to 250 pM. To maximize the interaction, the dyes were chosen so their emission spectra had considerable overlap with the absorption spectra of the Au-NP, which is common in MEF studies. If the dye molecules are too close to the surface of Au-NP, fluorescence quenching can occur instead of MEF. To try to observe this difference, silica-coated Au-NP were compared to citrate-based Au-NP; however, fluorescence quenching was observed with both Au-NP. This material is based upon work supported by the National Science Foundation under Grant Number NSF-ECCS-1306157.

Optimizing plasmon-enhanced fluorescence with nonlocal metallic nanospheres

DEFF Research Database (Denmark)

Tserkezis, Christos; Stefanou, Nikolaos; Wubs, Martijn

, through the recent Generalized Nonlocal Optical Response (GNOR) theory, the concurrent contribution of modal shifts and nonradiative losses, together with a reduced emitter excitation rate due to the decreased field intensity, lead always to a strong reduction of fluorescence (see Fig. 1). Finally, we...... identify situations where the common, intuitive recipe of tuning the NP modes to match λem can in fact lead to strong fluorescence quenching, instead of the anticipated enhancement. Our results highlight the necessity for careful modeling and design of plasmon-field-enhancement based applications....

Application of silver nanoparticles in the detection of SYBR Green I by surface enhanced Raman and surface-enhanced fluorescence

Science.gov (United States)

Guo, Wei; Wu, Jian; Wang, Chunyan; Zhang, Tian; Chen, Tao

2018-05-01

Silver nanomaterials have remarkable application in biomedical detection due to their unique surface plasmon resonance (SPR) characteristics. It can be used for surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). Current research elaborates a technique for improvement of SYBR Green I detection obtained from surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF) by silver nanoparticles with the average size about 70 nm. Primarily, SYBR Green I is an important fluorescent dye used in polymerase chain reaction (PCR). It is found that both Raman and fluorescence can be used for detection of this dye. Furthermore, the enhanced efficiency of the Raman and fluorescence by SERS and SEF is observed in this study, the enhancement factor for Raman signals is 3.2 × 103, and the fluorescence intensity bincreased two times by SEF. The quantitative detection of SYBR Green I by SERS and SEF can be achieved. The present work can be used to improve the detection of SYBR Green I by SERS and SEF. It would also be employed for high-sensitive detection of other materials in the future.

Player-Driven Video Analysis to Enhance Reflective Soccer Practice in Talent Development

Science.gov (United States)

Hjort, Anders; Henriksen, Kristoffer; Elbæk, Lars

2018-01-01

In the present article, we investigate the introduction of a cloud-based video analysis platform called Player Universe (PU). Video analysis is not a new performance-enhancing element in sports, but PU is innovative in how it facilitates reflective learning. Video analysis is executed in the PU platform by involving the players in the analysis…

Selective recognition of Pr3+ based on fluorescence enhancement sensor

International Nuclear Information System (INIS)

Ganjali, M.R.; Hosseini, M.; Ghafarloo, A.; Khoobi, M.; Faridbod, F.; Shafiee, A.; Norouzi, P.

2013-01-01

(E)-2-(1-(4-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) hydrazinecarbothioamide (L) has been used to detect trace amounts of praseodymium ion in acetonitrile–water solution (MeCN/H 2 O) by fluorescence spectroscopy. The fluorescent probe undergoes fluorescent emission intensity enhancement upon binding to Pr 3+ ions in MeCN/H 2 O (9/1:v/v) solution. The fluorescence enhancement of L is attributed to a 1:1 complex formation between L and Pr 3+ , which has been utilized as the basis for selective detection of Pr 3+ . The sensor can be applied to the quantification of praseodymium ion with a linear range of 1.6 × 10 −7 to 1.0 × 10 −5 M. The limit of detection was 8.3 × 10 −8 M. The sensor exhibits high selectivity toward praseodymium ions in comparison with common metal ions. The proposed fluorescent sensor was successfully used for determination of Pr 3+ in water samples. - Highlights: • A new fluorescent sensor is introduced as a selective probe for Pr 3+ detection. • Fluorescent intensity of the chemical probe enhances upon binding to Pr 3+ ion. • The sensor can be used for Pr 3+ determination in the range of 1.6 × 10 −7 –1.0 × 10 −5 M

Solvent induced fluorescence enhancement of graphene oxide studied by ultrafast spectroscopy

Science.gov (United States)

Zhao, Litao; Chen, Jinquan; He, Xiaoxiao; Yu, Xiantong; Yan, Shujun; Zhang, Sanjun; Pan, Haifeng; Xu, Jianhua

2018-05-01

Femtosecond transient absorption (TA) spectroscopy combined with picosecond time resolved fluorescence (TRF) were used to reveal the fluorescence kinetics of graphene oxide (GO) in water, ethanol and water-ethanol mixtures. Size-independent fluorescence of GO were observed in water, and pH-dependent fluorescence spectra could be fitted well by a triple emission relaxation with peaks around 440 nm, 500 nm, and 590 nm respectively. The results indicate that polycyclic aromatic hydrocarbons (PAHs) linked by oxygen-containing functional groups dominate GO's fluorescence emission. GO's fluorescence quantum yield was measured to be 2.8% in ethanol but 1.2% in water. The three decay components fluorescence decay, as well as the transient absorption dynamics with an offset, confirmed this solvent induced fluorescence enhancement. GO's Raman spectral signals showed that GO in ethanol has a smaller average size of PAHs than that of GO in water. Therefore, besides other enhancement effects reported in literatures, we proposed that solvents could also change the size of PAHs, resulting in a photoluminescence enhancement. Our experimental data demonstrates that GO's quantum yield could be up to 2.8% in water and 8.4% in ethanol and this observation may help ones to improve GO's photoluminescence efficiency as well as its applications in solution.

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.

Video enhancement of dental radiographic films

International Nuclear Information System (INIS)

Van Dis, M.L.; Beck, F.M.; Miles, D.A.

1989-01-01

A prototype video image display system, a real-time analog enhancer (RAE), was compared to conventional viewing conditions with the use of nonscreen dental films. When medium optical density films were evaluated, there was no significant difference in the number of radiographic details detected. Conventional viewing conditions allowed perception of more details when dark films were evaluated; however, the RAE unit allowed the perception of more details when light films were viewed

Nanoscale control of Ag nanostructures for plasmonic fluorescence enhancement of near-infrared dyes

KAUST Repository

Xie, Fang

2013-05-23

Potential utilization of proteins for early detection and diagnosis of various diseases has drawn considerable interest in the development of protein-based detection techniques. Metal induced fluorescence enhancement offers the possibility of increasing the sensitivity of protein detection in clinical applications. We report the use of tunable plasmonic silver nanostructures for the fluorescence enhancement of a near-infrared (NIR) dye (Alexa Fluor 790). Extensive fluorescence enhancement of ∼2 orders of magnitude is obtained by the nanoscale control of the Ag nanostructure dimensions and interparticle distance. These Ag nanostructures also enhanced fluorescence from a dye with very high quantum yield (7.8 fold for Alexa Fluor 488, quantum efficiency (Qy) = 0.92). A combination of greatly enhanced excitation and an increased radiative decay rate, leading to an associated enhancement of the quantum efficiency leads to the large enhancement. These results show the potential of Ag nanostructures as metal induced fluorescence enhancement (MIFE) substrates for dyes in the NIR "biological window" as well as the visible region. Ag nanostructured arrays fabricated by colloidal lithography thus show great potential for NIR dye-based biosensing applications. [Figure not available: see fulltext.] © 2013 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

Enhancement of the fluorescence of the samarium (III) complex by gadolinium (III)

International Nuclear Information System (INIS)

Yun-Xiang, C.; Zhang-Hua, L.

1988-01-01

The increase in sensitivity and selectivity of reactions in which colored species are formed by the addition of different metal ions is an area of research that has recently been developed. This phenomenon, which is sometimes called cocolaration effect, has been explained by the formation of mixed metal complex. The authors found an analogous phenomenon of reactions forming fluorescent complexes. The complexes of Sm(III)-thenoyltrifluoroacetone (TTA)-phenanthroline (Phen)-Triton-X-100 (TX-100) and Gd(III) (or La(III), Lu(III) and Y(III))-TTA-Phen-TX-100 had practically no fluorescence separately. Instead, a fluorescence-enhancement phenomenon caused by adding Gd or La, Lu and Y ions to the system was observed for the first time. The intensity of the enhanced fluorescence of Sm(III) complex was increased in the following order: La< Y< Lu< Gd. By analogy with cocoloration effect, the authors call this new fluorescence-enhancement phenomenon the co-fluorescence effect. The object of this work was to study the enhancement effect of Gd(III) on the fluorescence of the Sm(III)-TTA-Phen-TX-100 system. The recommended fluorimetric method has been applied to the determination of trace amounts of samarium in ytterbium oxide with satisfactory results. A general reaction mechanism for the system studied was proposed

A distance-dependent metal-enhanced fluorescence sensing platform based on molecular beacon design.

Science.gov (United States)

Zhou, Zhenpeng; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Cheng Zhi; Li, Na

2014-02-15

A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d(6) dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d(-3) dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1 nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design. © 2013 Elsevier B.V. All rights reserved.

Introducing Player-Driven Video Analysis to Enhance Reflective Soccer Practice

DEFF Research Database (Denmark)

Hjort, Anders; Elbæk, Lars; Henriksen, Kristoffer

2017-01-01

. The implementation and evaluation of PU took place in the FC Copenhagen (FCK) School of Excellence. Findings show that PU can improve youth football players’ reflection skills through consistent video analyses and tagging, that coaches are important as role models and providers of feedback, and that the use......In the present study, we investigated the introduction of a cloud-based video analysis platform called Player Universe (PU) in a Danish football club. Video analysis is not a new performance-enhancing element in sport, but PU is innovative in the way players and coaches produce footage and how...... it facilitates reflective learning. Video analysis is executed in the (PU) platform by involving the players in the analysis process, in the sense that they are encouraged to tag game actions in video-documented football matches. Following this, players can get virtual feedback from their coach. The philosophy...

Ns-scaled time-gated fluorescence lifetime imaging for forensic document examination

Science.gov (United States)

Zhong, Xin; Wang, Xinwei; Zhou, Yan

2018-01-01

A method of ns-scaled time-gated fluorescence lifetime imaging (TFLI) is proposed to distinguish different fluorescent substances in forensic document examination. Compared with Video Spectral Comparator (VSC) which can examine fluorescence intensity images only, TFLI can detect questioned documents like falsification or alteration. TFLI system can enhance weak signal by accumulation method. The two fluorescence intensity images of the interval delay time tg are acquired by ICCD and fitted into fluorescence lifetime image. The lifetimes of fluorescence substances are represented by different colors, which make it easy to detect the fluorescent substances and the sequence of handwritings. It proves that TFLI is a powerful tool for forensic document examination. Furthermore, the advantages of TFLI system are ns-scaled precision preservation and powerful capture capability.

Ultrasensitive near-infrared fluorescence-enhanced probe for in vivo nitroreductase imaging.

Science.gov (United States)

Li, Yuhao; Sun, Yun; Li, Jiachang; Su, Qianqian; Yuan, Wei; Dai, Yu; Han, Chunmiao; Wang, Qiuhong; Feng, Wei; Li, Fuyou

2015-05-20

Nitroreductase (NTR) can be overexpressed in hypoxic tumors, thus the selective and efficient detection of NTR is of great importance. To date, although a few optical methods have been reported for the detection of NTR in solution, an effective optical probe for NTR monitoring in vivo is still lacking. Therefore, it is necessary to develop a near-infrared (NIR) fluorescent detection probe for NTR. In this study, five NIR cyanine dyes with fluorescence reporting structure decorated with different nitro aromatic groups, Cy7-1-5, have been designed and explored for possible rapid detection of NTR. Our experimental results presented that only a para-nitro benzoate group modified cyanine probe (Cy7-1) could serve as a rapid NIR fluorescence-enhanced probe for monitoring and bioimaging of NTR. The structure-function relationship has been revealed by theoretical study. The linker connecting the detecting and fluorescence reporting groups and the nitro group position is a key factor for the formation of hydrogen bonds and spatial structure match, inducing the NTR catalytic ability enhancement. The in vitro response and mechanism of the enzyme-catalyzed reduction of Cy7-1 have been investigated through kinetic optical studies and other methods. The results have indicated that an electro-withdrawing group induced electron-transfer process becomes blocked when Cy7-1 is catalytically reduced to Cy7-NH2 by NTR, which is manifested in enhanced fluorescence intensity during the detection process. Confocal fluorescence imaging of hypoxic A549 cells has confirmed the NTR detection ability of Cy7-1 at the cellular level. Importantly, Cy7-1 can detect tumor hypoxia in a murine hypoxic tumor model, showing a rapid and significant enhancement of its NIR fluorescence characteristics suitable for fluorescence bioimaging. This method may potentially be used for tumor hypoxia diagnosis.

Novel room temperature ionic liquid for fluorescence enhancement of Eu3+ and Tb3+

International Nuclear Information System (INIS)

Shyamala Devi, V.; Maji, S.; Viswanathan, K.S.

2011-01-01

The newly prepared ionic liquid, 1-butyl-3-methylimidazolium benzoate, ([bmim][BA]), was found to enhance the fluorescence of Eu 3+ and Tb 3+ . The fluorescence enhancement resulted from a sensitization of the lanthanide fluorescence by the benzoate anion of the ionic liquid, [bmim][BA], and a reduction in the non-radiative channels in the non-aqueous environment provided by the ionic liquid. However, the fluorescence enhancement of the lanthanides in the ionic liquid was limited due to the operation of the inner filter effect, which resulted from the strong absorption of the benzoate. The inner filter effect was minimized by observing the Eu 3+ fluorescence using a front face geometry and also by diluting the lanthanide-[bmim][BA] system, using another ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf 2 N]), as a solvent. In the case of Tb 3+ , the emission from the lanthanide was masked by the strong emission from the ionic liquid in the region 450-580 nm. The long lived Tb 3+ emission was therefore observed using delayed gated detection, where an appropriate delay was used to discriminate against the short lived emission from the ionic liquid. The large fluorescence enhancement due to ligand sensitized fluorescence observed with [bmim][BA] diluted in [bmim][Tf 2 N], leads to nanomolar detection of the lanthanides. This is, to the best of our knowledge, the first report of an ionic liquid being employed for ligand sensitized fluorescence enhancement of lanthanides. - Research highlights: →The use of an ionic liquid to enhance the fluorescence of lanthanides, Eu 3+ and Tb 3+ is discussed in this paper. → This study represents the first report of the use of a tailored ionic liquid for the purposes of fluorescence enhancement. → The fluorescence enhancement is achieved both a process of ligand sensitization, as well as reducing the non-radiative decay channels. → The first point is achieved by the use of an anion capable

Enhancing Cognition with Video Games: A Multiple Game Training Study

OpenAIRE

Oei, Adam C.; Patterson, Michael D.

2013-01-01

Background Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. Methodology/Principal Findings We instructed 5 groups of non-gamer participants to play one game each on a mob...

Underwater video enhancement using multi-camera super-resolution

Science.gov (United States)

Quevedo, E.; Delory, E.; Callicó, G. M.; Tobajas, F.; Sarmiento, R.

2017-12-01

Image spatial resolution is critical in several fields such as medicine, communications or satellite, and underwater applications. While a large variety of techniques for image restoration and enhancement has been proposed in the literature, this paper focuses on a novel Super-Resolution fusion algorithm based on a Multi-Camera environment that permits to enhance the quality of underwater video sequences without significantly increasing computation. In order to compare the quality enhancement, two objective quality metrics have been used: PSNR (Peak Signal-to-Noise Ratio) and the SSIM (Structural SIMilarity) index. Results have shown that the proposed method enhances the objective quality of several underwater sequences, avoiding the appearance of undesirable artifacts, with respect to basic fusion Super-Resolution algorithms.

Local adaptive tone mapping for video enhancement

Science.gov (United States)

Lachine, Vladimir; Dai, Min (.

2015-03-01

As new technologies like High Dynamic Range cameras, AMOLED and high resolution displays emerge on consumer electronics market, it becomes very important to deliver the best picture quality for mobile devices. Tone Mapping (TM) is a popular technique to enhance visual quality. However, the traditional implementation of Tone Mapping procedure is limited by pixel's value to value mapping, and the performance is restricted in terms of local sharpness and colorfulness. To overcome the drawbacks of traditional TM, we propose a spatial-frequency based framework in this paper. In the proposed solution, intensity component of an input video/image signal is split on low pass filtered (LPF) and high pass filtered (HPF) bands. Tone Mapping (TM) function is applied to LPF band to improve the global contrast/brightness, and HPF band is added back afterwards to keep the local contrast. The HPF band may be adjusted by a coring function to avoid noise boosting and signal overshooting. Colorfulness of an original image may be preserved or enhanced by chroma components correction by means of saturation function. Localized content adaptation is further improved by dividing an image to a set of non-overlapped regions and modifying each region individually. The suggested framework allows users to implement a wide range of tone mapping applications with perceptional local sharpness and colorfulness preserved or enhanced. Corresponding hardware circuit may be integrated in camera, video or display pipeline with minimal hardware budget

Video-Enhanced Telemedicine Improves the Care of Acutely Injured Burn Patients in a Rural State.

Science.gov (United States)

Wibbenmeyer, Lucy; Kluesner, Karen; Wu, Hongqian; Eid, Anas; Heard, Jason; Mann, Benjamin; Pauley, Alison; Peek-Asa, Corrine

The acute care of burn patients is critical and can be a daunting experience for emergency personnel because of the scarcity of burn injuries. Telemedicine that incorporates a visual component can provide immediate expertise in the treatment and management of these injuries. The authors sought to evaluate the addition of video telemedicine to our current telephone burn transfer program. During a 2-year period, 282 patients, 59.4% of all burn patients transferred from outside hospitals, were enrolled in the study. In addition to the scripted call with the charge nurse (ChargeRN) and the accepting physician, nine hospitals also transmitted video images of the wounds before transfer as part of a store and forward telemedicine transfer program (77, 27.6%). The accuracy of burn size estimations (BSA burned) and management changes (fluid requirements, transfer mode, and final disposition) were analyzed between the telephones-only sites (T only) and the video-enhanced sites. Referringstaff participating in video-enhanced telemedicine were sent a Google survey assessing their experience the following day. The referring staff (Referringstaff) was correct in their burn assessment 20% of the time. Video assessment improved the ChargeRN BSA burned and resulted in more accurate fluid resuscitation (P = .030), changes in both transportation mode (P = .042), and disposition decisions (P = .20). The majority of the Referringstaff found that video-enhanced telemedicine helped them communicate with the burn staff more effectively (3.4 ± 0.37, scale 1-4). This study reports the successful implementation of video-enhanced telemedicine pilot project in a rural state. Video-enhanced telemedicine using a store and forward process improved burn size estimation and facilitated management changes. Although not quantitatively assessed, the low cost of the system coupled with the changes in transportation and disposition strongly suggests a decrease in healthcare costs associated with

Fluorescence enhancement in large-scale self-assembled gold nanoparticle double arrays

International Nuclear Information System (INIS)

Chekini, M.; Bierwagen, J.; Cunningham, A.; Bürgi, T.; Filter, R.; Rockstuhl, C.

2015-01-01

Localized surface plasmon resonances excited in metallic nanoparticles confine and enhance electromagnetic fields at the nanoscale. This is particularly pronounced in dimers made from two closely spaced nanoparticles. When quantum emitters, such as dyes, are placed in the gap of those dimers, their absorption and emission characteristics can be modified. Both processes have to be considered when aiming to enhance the fluorescence from the quantum emitters. This is particularly challenging for dimers, since the electromagnetic properties and the enhanced fluorescence sensitively depend on the distance between the nanoparticles. Here, we use a layer-by-layer method to precisely control the distances in such systems. We consider a dye layer deposited on top of an array of gold nanoparticles or integrated into a central position of a double array of gold nanoparticles. We study the effect of the spatial arrangement and the average distance on the plasmon-enhanced fluorescence. We found a maximum of a 99-fold increase in the fluorescence intensity of the dye layer sandwiched between two gold nanoparticle arrays. The interaction of the dye layer with the plasmonic system also causes a spectral shift in the emission wavelengths and a shortening of the fluorescence life times. Our work paves the way for large-scale, high throughput, and low-cost self-assembled functionalized plasmonic systems that can be used as efficient light sources

Enhancing cognition with video games: a multiple game training study.

Directory of Open Access Journals (Sweden)

Adam C Oei

Full Text Available Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands.We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch for one hour a day/five days a week over four weeks (20 hours. Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training.Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be attributed to near-transfer effects.

Enhancing Cognition with Video Games: A Multiple Game Training Study

Science.gov (United States)

Oei, Adam C.; Patterson, Michael D.

2013-01-01

Background Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. Methodology/Principal Findings We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch) for one hour a day/five days a week over four weeks (20 hours). Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training. Conclusion/Significance Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be

Enhancing cognition with video games: a multiple game training study.

Science.gov (United States)

Oei, Adam C; Patterson, Michael D

2013-01-01

Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch) for one hour a day/five days a week over four weeks (20 hours). Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training. Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be attributed to near-transfer effects.

Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography

Science.gov (United States)

Pan, Y. T.; Xie, T. Q.; Du, C. W.; Bastacky, S.; Meyers, S.; Zeidel, M. L.

2003-12-01

We report an experimental study of the possibility of enhancing early bladder cancer diagnosis with fluorescence-image-guided endoscopic optical coherence tomography (OCT). After the intravesical instillation of a 10% solution of 5-aminolevulinic acid, simultaneous fluorescence imaging (excitation of 380-420 nm, emission of 620-700 nm) and OCT are performed on rat bladders to identify the photochemical and morphological changes associated with uroepithelial tumorigenesis. The preliminary results of our ex vivo study reveal that both fluorescence and OCT can identify early uroepithelial cancers, and OCT can detect precancerous lesions (e.g., hyperplasia) that fluorescence may miss. This suggests that a cystoscope combining 5-aminolevulinic acid fluorescence and OCT imaging has the potential to enhance the efficiency and sensitivity of early bladder cancer diagnosis.

Nanoscale control of Ag nanostructures for plasmonic fluorescence enhancement of near-infrared dyes

KAUST Repository

Xie, Fang; Pang, Jing S.; Centeno, Anthony; Ryan, Mary P.; Riley, D. Jason; Alford, Neil M.

2013-01-01

of increasing the sensitivity of protein detection in clinical applications. We report the use of tunable plasmonic silver nanostructures for the fluorescence enhancement of a near-infrared (NIR) dye (Alexa Fluor 790). Extensive fluorescence enhancement of ∼2

Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles

Science.gov (United States)

Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D.; Chang, Huan-Cheng; Ye, Jing Yong

2012-01-01

Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs). PMID:22808436

Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles.

Science.gov (United States)

Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D; Chang, Huan-Cheng; Ye, Jing Yong

2012-07-01

Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs).

Platinum plasmonic nanostructure arrays for massively parallel single-molecule detection based on enhanced fluorescence measurements

International Nuclear Information System (INIS)

Saito, Toshiro; Takahashi, Satoshi; Obara, Takayuki; Itabashi, Naoshi; Imai, Kazumichi

2011-01-01

We fabricated platinum bowtie nanostructure arrays producing fluorescence enhancement and evaluated their performance using two-photon photoluminescence and single-molecule fluorescence measurements. A comprehensive selection of suitable materials was explored by electromagnetic simulation and Pt was chosen as the plasmonic material for visible light excitation near 500 nm, which is preferable for multicolor dye-labeling applications like DNA sequencing. The observation of bright photoluminescence (λ = 500-600 nm) from each Pt nanostructure, induced by irradiation at 800 nm with a femtosecond laser pulse, clearly indicates that a highly enhanced local field is created near the Pt nanostructure. The attachment of a single dye molecule was attempted between the Pt triangles of each nanostructure by using selective immobilization chemistry. The fluorescence intensities of the single dye molecule localized on the nanostructures were measured. A highly enhanced fluorescence, which was increased by a factor of 30, was observed. The two-photon photoluminescence intensity and fluorescence intensity showed qualitatively consistent gap size dependence. However, the average fluorescence enhancement factor was rather repressed even in the nanostructure with the smallest gap size compared to the large growth of photoluminescence. The variation of the position of the dye molecule attached to the nanostructure may influence the wide distribution of the fluorescence enhancement factor and cause the rather small average value of the fluorescence enhancement factor.

Synergistic Combination of Unquenching and Plasmonic Fluorescence Enhancement in Fluorogenic Nucleic Acid Hybridization Probes.

Science.gov (United States)

Vietz, Carolin; Lalkens, Birka; Acuna, Guillermo P; Tinnefeld, Philip

2017-10-11

Fluorogenic nucleic acid hybridization probes are widely used for detecting and quantifying nucleic acids. The achieved sensitivity strongly depends on the contrast between a quenched closed form and an unquenched opened form with liberated fluorescence. So far, this contrast was improved by improving the quenching efficiency of the closed form. In this study, we modularly combine these probes with optical antennas used for plasmonic fluorescence enhancement and study the effect of the nanophotonic structure on the fluorescence of the quenched and the opened form. As quenched fluorescent dyes are usually enhanced more by fluorescence enhancement, a detrimental reduction of the contrast between closed and opened form was anticipated. In contrast, we could achieve a surprising increase of the contrast with full additivity of quenching of the dark form and fluorescence enhancement of the bright form. Using single-molecule experiments, we demonstrate that the additivity of the two mechanisms depends on the perfect quenching in the quenched form, and we delineate the rules for new nucleic acid probes for enhanced contrast and absolute brightness. Fluorogenic hybridization probes optimized not only for quenching but also for the brightness of the open form might find application in nucleic acid assays with PCR avoiding detection schemes.

Efficient Enhancement for Spatial Scalable Video Coding Transmission

Directory of Open Access Journals (Sweden)

Mayada Khairy

2017-01-01

Full Text Available Scalable Video Coding (SVC is an international standard technique for video compression. It is an extension of H.264 Advanced Video Coding (AVC. In the encoding of video streams by SVC, it is suitable to employ the macroblock (MB mode because it affords superior coding efficiency. However, the exhaustive mode decision technique that is usually used for SVC increases the computational complexity, resulting in a longer encoding time (ET. Many other algorithms were proposed to solve this problem with imperfection of increasing transmission time (TT across the network. To minimize the ET and TT, this paper introduces four efficient algorithms based on spatial scalability. The algorithms utilize the mode-distribution correlation between the base layer (BL and enhancement layers (ELs and interpolation between the EL frames. The proposed algorithms are of two categories. Those of the first category are based on interlayer residual SVC spatial scalability. They employ two methods, namely, interlayer interpolation (ILIP and the interlayer base mode (ILBM method, and enable ET and TT savings of up to 69.3% and 83.6%, respectively. The algorithms of the second category are based on full-search SVC spatial scalability. They utilize two methods, namely, full interpolation (FIP and the full-base mode (FBM method, and enable ET and TT savings of up to 55.3% and 76.6%, respectively.

Enhanced visual short-term memory in action video game players.

Science.gov (United States)

Blacker, Kara J; Curby, Kim M

2013-08-01

Visual short-term memory (VSTM) is critical for acquiring visual knowledge and shows marked individual variability. Previous work has illustrated a VSTM advantage among action video game players (Boot et al. Acta Psychologica 129:387-398, 2008). A growing body of literature has suggested that action video game playing can bolster visual cognitive abilities in a domain-general manner, including abilities related to visual attention and the speed of processing, providing some potential bases for this VSTM advantage. In the present study, we investigated the VSTM advantage among video game players and assessed whether enhanced processing speed can account for this advantage. Experiment 1, using simple colored stimuli, revealed that action video game players demonstrate a similar VSTM advantage over nongamers, regardless of whether they are given limited or ample time to encode items into memory. Experiment 2, using complex shapes as the stimuli to increase the processing demands of the task, replicated this VSTM advantage, irrespective of encoding duration. These findings are inconsistent with a speed-of-processing account of this advantage. An alternative, attentional account, grounded in the existing literature on the visuo-cognitive consequences of video game play, is discussed.

Fluorescence Enhancement of Fluorescent Unnatural Streptavidin by Binding of a Biotin Analogue with Spacer Tail and Its Application to Biotin Sensing

Directory of Open Access Journals (Sweden)

Xianwei Zhu

2014-01-01

Full Text Available We designed a novel molecular biosensing system for the detection of biotin, an important vitamin by the combination of fluorescent unnatural streptavidin with a commercialized biotin-(AC52-hydrazide. A fluorescent unnatural amino acid, BODIPY-FL-aminophenylalanine (BFLAF, was position-specifically incorporated into Trp120 of streptavidin by four-base codon method. Fluorescence of the Trp120BFLAF mutant streptavidin was enhanced by the addition of biotin-(AC52-hydrazide with the concentration dependent, whereas fluorescence enhancement was not observed at all by the addition of natural biotin. It was considered that the spacer tail of biotin-(AC52-hydrazide may disturb the fluorescence quenching of the Trp120BFLAF by Trp79 and Trp108 of the neighbor subunit. Therefore, biotin sensing was carried out by the competitive binding reaction of biotin-(AC52-hydrazide and natural biotin to the fluorescent mutant streptavidin. The fluorescence intensity decreased by increasing free biotin concentration. The result suggested that molecular biosensor for small ligand could be successfully designed by the pair of fluorescent mutant binding protein and ligand analogue.

Player-Driven Video Analysis to Enhance Reflective Soccer Practice in Talent Development

DEFF Research Database (Denmark)

Hjort, Anders; Henriksen, Kristoffer; Elbæk, Lars

2018-01-01

consistent video analyses and tagging; coaches are important as role models and providers of feedback; and that the use of the platform primarily stimulated deliberate practice activities. PU can be seen as a source of inspiration for soccer players and clubs as to how analytical platforms can motivate......In the present article, we investigate the introduction of a cloud-based video analysis platform called Player Universe (PU). Video analysis is not a new performance-enhancing element in sports, but PU is innovative in how it facilitates reflective learning. Video analysis is executed in the PU...... platform by involving the players in the analysis process, in the sense that they are encouraged to tag game actions in video-documented soccer matches. Following this, players can get virtual feedback from their coach. Findings show that PU can improve youth soccer players' reflection skills through...

Prospective Teachers' Views about Video-Enhanced General Biology Instruction

Science.gov (United States)

Çetin, Gülcan

2014-01-01

The aim of the study is to determine the views of the prospective physics and chemistry teachers about the video-enhanced General Biology instruction. The participants included 19 second-year prospective teachers (10 in Physics and 9 in Chemistry Education) at Necatibey Faculty of Education, Balikesir University, Turkey in the 2011-2012 academic…

The enhanced cyan fluorescent protein: a sensitive pH sensor for fluorescence lifetime imaging.

Science.gov (United States)

Poëa-Guyon, Sandrine; Pasquier, Hélène; Mérola, Fabienne; Morel, Nicolas; Erard, Marie

2013-05-01

pH is an important parameter that affects many functions of live cells, from protein structure or function to several crucial steps of their metabolism. Genetically encoded pH sensors based on pH-sensitive fluorescent proteins have been developed and used to monitor the pH of intracellular compartments. The quantitative analysis of pH variations can be performed either by ratiometric or fluorescence lifetime detection. However, most available genetically encoded pH sensors are based on green and yellow fluorescent proteins and are not compatible with multicolor approaches. Taking advantage of the strong pH sensitivity of enhanced cyan fluorescent protein (ECFP), we demonstrate here its suitability as a sensitive pH sensor using fluorescence lifetime imaging. The intracellular ECFP lifetime undergoes large changes (32 %) in the pH 5 to pH 7 range, which allows accurate pH measurements to better than 0.2 pH units. By fusion of ECFP with the granular chromogranin A, we successfully measured the pH in secretory granules of PC12 cells, and we performed a kinetic analysis of intragranular pH variations in living cells exposed to ammonium chloride.

Novel room temperature ionic liquid for fluorescence enhancement of Eu{sup 3+} and Tb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Shyamala Devi, V.; Maji, S. [Materials Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Viswanathan, K.S., E-mail: vish@igcar.gov.i [Materials Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

2011-04-15

The newly prepared ionic liquid, 1-butyl-3-methylimidazolium benzoate, ([bmim][BA]), was found to enhance the fluorescence of Eu{sup 3+} and Tb{sup 3+}. The fluorescence enhancement resulted from a sensitization of the lanthanide fluorescence by the benzoate anion of the ionic liquid, [bmim][BA], and a reduction in the non-radiative channels in the non-aqueous environment provided by the ionic liquid. However, the fluorescence enhancement of the lanthanides in the ionic liquid was limited due to the operation of the inner filter effect, which resulted from the strong absorption of the benzoate. The inner filter effect was minimized by observing the Eu{sup 3+} fluorescence using a front face geometry and also by diluting the lanthanide-[bmim][BA]system, using another ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf{sub 2}N]), as a solvent. In the case of Tb{sup 3+}, the emission from the lanthanide was masked by the strong emission from the ionic liquid in the region 450-580 nm. The long lived Tb{sup 3+} emission was therefore observed using delayed gated detection, where an appropriate delay was used to discriminate against the short lived emission from the ionic liquid. The large fluorescence enhancement due to ligand sensitized fluorescence observed with [bmim][BA]diluted in [bmim][Tf{sub 2}N], leads to nanomolar detection of the lanthanides. This is, to the best of our knowledge, the first report of an ionic liquid being employed for ligand sensitized fluorescence enhancement of lanthanides. - Research highlights: {yields}The use of an ionic liquid to enhance the fluorescence of lanthanides, Eu{sup 3+} and Tb{sup 3+} is discussed in this paper. {yields} This study represents the first report of the use of a tailored ionic liquid for the purposes of fluorescence enhancement. {yields} The fluorescence enhancement is achieved both a process of ligand sensitization, as well as reducing the non-radiative decay channels. {yields

Detection of DNA hybridization based on SnO2 nanomaterial enhanced fluorescence

International Nuclear Information System (INIS)

Gu Cuiping; Huang Jiarui; Ni Ning; Li Minqiang; Liu Jinhuai

2008-01-01

In this paper, enhanced fluorescence emissions were firstly investigated based on SnO 2 nanomaterial, and its application in the detection of DNA hybridization was also demonstrated. The microarray of SnO 2 nanomaterial was fabricated by the vapour phase transport method catalyzed by patterned Au nanoparticles on a silicon substrate. A probe DNA was immobilized on the substrate with patterned SnO 2 nanomaterial, respectively, by covalent and non-covalent linking schemes. When a fluorophore labelled target DNA was hybridized with a probe DNA on the substrate, fluorescence emissions were only observed on the surface of SnO 2 nanomaterial, which indicated the property of enhancing fluorescence signals from the SnO 2 nanomaterial. By comparing the different fluorescence images from covalent and non-covalent linking schemes, the covalent method was confirmed to be more effective for immobilizing a probe DNA. With the combined use of SnO 2 nanomaterial and the covalent linking scheme, the target DNA could be detected at a very low concentration of 10 fM. And the stability of SnO 2 nanomaterial under the experimental conditions was also compared with silicon nanowires. The findings strongly suggested that SnO 2 nanomaterial could be extensively applied in detections of biological samples with enhancing fluorescence property and high stability

Enhanced-locality fiber-optic two-photon-fluorescence live-brain interrogation

Energy Technology Data Exchange (ETDEWEB)

Fedotov, I. V.; Doronina-Amitonova, L. V. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Kurchatov Institute National Research Center, Moscow (Russian Federation); Sidorov-Biryukov, D. A.; Fedotov, A. B. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Anokhin, K. V. [Kurchatov Institute National Research Center, Moscow (Russian Federation); P.K. Anokhin Institute of Normal Physiology, Russian Academy of Medical Sciences, Moscow (Russian Federation); Kilin, S. Ya. [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus); Sakoda, K. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Zheltikov, A. M. [International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region 1430125 (Russian Federation); Department of Physics and Astronomy, Texas A and M University, College Station, Texas 77843 (United States); Center of Photochemistry, Russian Academy of Sciences, ul. Novatorov 7a, Moscow 117421 (Russian Federation)

2014-02-24

Two-photon excitation is shown to substantially enhance the locality of fiber-based optical interrogation of strongly scattering biotissues. In our experiments, a high-numerical-aperture, large-core-are fiber probe is used to deliver the 200-fs output of a 100-MHz mode-locked ytterbium fiber laser to samples of live mouse brain, induce two-photon fluorescence of nitrogen–vacancy centers in diamond markers in brain sample. Fiber probes with a high numerical aperture and a large core area are shown to enable locality enhancement in fiber-laser–fiber-probe two-photon brain excitation and interrogation without sacrificing the efficiency of fluorescence response collection.

Ensemble of Chaotic and Naive Approaches for Performance Enhancement in Video Encryption

Directory of Open Access Journals (Sweden)

Jeyamala Chandrasekaran

2015-01-01

Full Text Available Owing to the growth of high performance network technologies, multimedia applications over the Internet are increasing exponentially. Applications like video conferencing, video-on-demand, and pay-per-view depend upon encryption algorithms for providing confidentiality. Video communication is characterized by distinct features such as large volume, high redundancy between adjacent frames, video codec compliance, syntax compliance, and application specific requirements. Naive approaches for video encryption encrypt the entire video stream with conventional text based cryptographic algorithms. Although naive approaches are the most secure for video encryption, the computational cost associated with them is very high. This research work aims at enhancing the speed of naive approaches through chaos based S-box design. Chaotic equations are popularly known for randomness, extreme sensitivity to initial conditions, and ergodicity. The proposed methodology employs two-dimensional discrete Henon map for (i generation of dynamic and key-dependent S-box that could be integrated with symmetric algorithms like Blowfish and Data Encryption Standard (DES and (ii generation of one-time keys for simple substitution ciphers. The proposed design is tested for randomness, nonlinearity, avalanche effect, bit independence criterion, and key sensitivity. Experimental results confirm that chaos based S-box design and key generation significantly reduce the computational cost of video encryption with no compromise in security.

Differential tissue expression of enhanced green fluorescent protein in ‘Green mice’

OpenAIRE

Ma, De-Fu; Tezuka, Hideo; Kondo, Tetsuo; Sudo, Katsuko; Niu, Dong-Feng; Nakazawa, Tadao; Kawasaki, Tomonori; Yamane, Tetsu; Nakamura, Nobuki; Katoh, Ryohei

2010-01-01

In order to clarify tissue expression of enhanced green fluorescent protein (EGFP) in ‘green mice’ from a transgenic line having an EGFP cDNA under the control of a chicken beta-actin promoter and cytomegalovirus enhancer, we studied the expression of EGFP in various organs and tissues from these ‘green mice’ by immunohistochemistry with anti- EGFP antibody in conjunction with direct observation for EGFP fluorescence using confocal laser scanning microscopy. On i...

Metal Nanoparticles/Porous Silicon Microcavity Enhanced Surface Plasmon Resonance Fluorescence for the Detection of DNA

Directory of Open Access Journals (Sweden)

Jiajia Wang

2018-02-01

Full Text Available A porous silicon microcavity (PSiMC with resonant peak wavelength of 635 nm was fabricated by electrochemical etching. Metal nanoparticles (NPs/PSiMC enhanced fluorescence substrates were prepared by the electrostatic adherence of Au NPs that were distributed in PSiMC. The Au NPs/PSiMC device was used to characterize the target DNA immobilization and hybridization with its complementary DNA sequences marked with Rhodamine red (RRA. Fluorescence enhancement was observed on the Au NPs/PSiMC device substrate; and the minimum detection concentration of DNA ran up to 10 pM. The surface plasmon resonance (SPR of the MC substrate; which is so well-positioned to improve fluorescence enhancement rather the fluorescence enhancement of the high reflection band of the Bragg reflector; would welcome such a highly sensitive in biosensor.

Metal Nanoparticles/Porous Silicon Microcavity Enhanced Surface Plasmon Resonance Fluorescence for the Detection of DNA.

Science.gov (United States)

Wang, Jiajia; Jia, Zhenhong

2018-02-23

A porous silicon microcavity (PSiMC) with resonant peak wavelength of 635 nm was fabricated by electrochemical etching. Metal nanoparticles (NPs)/PSiMC enhanced fluorescence substrates were prepared by the electrostatic adherence of Au NPs that were distributed in PSiMC. The Au NPs/PSiMC device was used to characterize the target DNA immobilization and hybridization with its complementary DNA sequences marked with Rhodamine red (RRA). Fluorescence enhancement was observed on the Au NPs/PSiMC device substrate; and the minimum detection concentration of DNA ran up to 10 pM. The surface plasmon resonance (SPR) of the MC substrate; which is so well-positioned to improve fluorescence enhancement rather the fluorescence enhancement of the high reflection band of the Bragg reflector; would welcome such a highly sensitive in biosensor.

Enhanced efficiency of a fluorescing nanoparticle with a silver shell

Energy Technology Data Exchange (ETDEWEB)

Choy, Wallace C H; Chen Xuewen [Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road (Hong Kong); He Sailing [Centre for Optical and Electromagnetic Research, Zhejiang University, Zhijingang campus, Hangzhou 310058 (China)], E-mail: chchoy@eee.hku.hk

2009-09-01

Spontaneous emission (SE) rate and the fluorescence efficiency of a bare fluorescing nanoparticle (NP) and the NP with a silver nanoshell are analyzed rigorously by using a classical electromagnetic approach with the consideration of the nonlocal effect of the silver nano-shell. The dependences of the SE rate and the fluorescence efficiency on the core-shell structure are carefully studied and the physical interpretations of the results are addressed. The results show that the SE rate of a bare NP is much slower than that in the infinite medium by almost an order of magnitude and consequently the fluorescence efficiency is usually low. However, by encapsulating the NP with a silver shell, highly efficient fluorescence can be achieved as a result of a large Purcell enhancement and high out-coupling efficiency (OQE) for a well-designed core-shell structure. We also show that a higher SE rate may not offer a larger fluorescence efficiency since the fluorescence efficiency not only depends on the internal quantum yield but also the OQE.

Preparation of Plasmonic Platforms of Silver Wires on Gold Mirrors and Their Application to Surface Enhanced Fluorescence

Science.gov (United States)

2015-01-01

In this report we describe a preparation of silver wires (SWs) on gold mirrors and its application to surface enhanced fluorescence (SEF) using a new methodology. Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms. The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors. Fluorescence enhancement was studied using methyl azadioxatriangulenium chloride (Me-ADOTA·Cl) dye in PVA spin-coated on a clean glass coverslip. New Plasmonic Platforms (PPs) were assembled by placing a mirror with SWs in contact with a glass coverslip spin-coated with a uniform Me-ADOTA·Cl film. It was shown that surface enhanced fluorescence is a real phenomenon, not just an enhancement of the fluorescence signal due to an accumulation of the fluorophore on rough nanostructure surfaces. The average fluorescence enhancement was found to be about 15-fold. The lifetime of Me-ADOTA·Cl dye was significantly reduced (∼4 times) in the presence of SWs. Moreover, fluorescence enhancement and lifetime did not show any dependence on the excitation light polarization. PMID:25296293

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.

Video game training does not enhance cognitive ability: A comprehensive meta-analytic investigation.

Science.gov (United States)

Sala, Giovanni; Tatlidil, K Semir; Gobet, Fernand

2018-02-01

As a result of considerable potential scientific and societal implications, the possibility of enhancing cognitive ability by training has been one of the most influential topics of cognitive psychology in the last two decades. However, substantial research into the psychology of expertise and a recent series of meta-analytic reviews have suggested that various types of cognitive training (e.g., working memory training) benefit performance only in the trained tasks. The lack of skill generalization from one domain to different ones-that is, far transfer-has been documented in various fields of research such as working memory training, music, brain training, and chess. Video game training is another activity that has been claimed by many researchers to foster a broad range of cognitive abilities such as visual processing, attention, spatial ability, and cognitive control. We tested these claims with three random-effects meta-analytic models. The first meta-analysis (k = 310) examined the correlation between video game skill and cognitive ability. The second meta-analysis (k = 315) dealt with the differences between video game players and nonplayers in cognitive ability. The third meta-analysis (k = 359) investigated the effects of video game training on participants' cognitive ability. Small or null overall effect sizes were found in all three models. These outcomes show that overall cognitive ability and video game skill are only weakly related. Importantly, we found no evidence of a causal relationship between playing video games and enhanced cognitive ability. Video game training thus represents no exception to the general difficulty of obtaining far transfer. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Video Enhancement and Dynamic Range Control of HDR Sequences for Automotive Applications

Directory of Open Access Journals (Sweden)

Giovanni Ramponi

2007-01-01

Full Text Available CMOS video cameras with high dynamic range (HDR output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorithms have been proposed in the literature to reduce the dynamic range of still pictures. Anyway, extending the available methods to video is not straightforward, due to the peculiar nature of video data. We propose an algorithm for both reducing the dynamic range of video sequences and enhancing its appearance, thus improving visual quality and reducing temporal artifacts. We also provide an optimized version of our algorithm for a viable hardware implementation on an FPGA. The feasibility of this implementation is demonstrated by means of a case study.

Copper spherical cavity arrays: Fluorescence enhancement in PFO films

Energy Technology Data Exchange (ETDEWEB)

Spada, Edna R., E-mail: edspada@gmail.com [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil); Valente, Gustavo T.; Pereira-da-Silva, Marcelo A. [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil); Sartorelli, Maria L. [Departamento de Física, Universidade Federal de Santa Catarina, Caixa Postal 476, 88040-900, Florianópolis, SC (Brazil); Guimarães, Francisco E.G.; Faria, Roberto M. [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil)

2017-01-15

This manuscript addresses the use of a well-ordered antidot copper nanostructure as a active substrate for surface enhancement fluorescence (SEF). The antidot array was produced by electrodeposition and nanosphere lithography and characterized by microscopy technique, its successful application as SEF-active substrates was verified using polyfluorene (PFO) as a probe layer. Atomic force microscopy (AFM) was used to evaluate the regularity of the metal surface as well PFO coated process and confocal laser fluorescence microscopy (CLSM) to determine the behavior exhibited by the fluorescent layer due to the existence of the nanostructured surface. No accumulation PFO in the cavities was detected and the more intense emission regions coincides with the position of the cavities and is at about one order of magnitude higher.

Silver-graphene oxide based plasmonic spacer for surface plasmon-coupled fluorescence emission enhancements

Science.gov (United States)

Badiya, Pradeep Kumar; Srinivasan, Venkatesh; Sathish Ramamurthy, Sai

2017-06-01

We report the application of single layered graphene oxide (SLGO) and silver decorated SLGO (Ag-SLGO) as plasmonic spacer material for obtaining enhanced fluorescence from a Rhodamine 6G (Rh6G) radiating dipole in a surface plasmon-coupled emission platform. To this end, we have decorated SLGO with biphasic silver nanoparticles using an in situ deposition technique to achieve 112-fold fluorescence enhancements.

Enhancement of the fluorescence intensity of DNA intercalators using nano-imprinted 2-dimensional photonic crystal

International Nuclear Information System (INIS)

Endo, Tatsuro; Ueda, China; Hisamoto, Hideaki; Kajita, Hiroshi; Okuda, Norimichi; Tanaka, Satoru

2013-01-01

We have fabricated polymer-based 2-dimensional photonic crystals that play a key role in enhancing the fluorescence of DNA intercalators. Highly ordered 2-dimensional photonic crystals possessing triangle-shaped and nm-sized hole arrays were fabricated on a 100 μm thick polymer film using nano-imprint lithography. Samples of double-stranded DNAs (sizes: 4361 and 48502 bp; concentration: 1 pM to 10 nM) were adsorbed on the surface of the 2-dimensional photonic crystal by electrostatic interactions and then treated with intercalators. It is found that the fluorescence intensity of the intercalator is enhanced by a factor of up to 10 compared to the enhancement in the absence of the 2-dimensional photonic crystal. Fluorescence intensity increases with increasing length and concentration of the DNAs. If the 2-dimensional photonic crystal is used as a Bragg reflection mirror, the enhancement of fluorescence intensity can be easily observed using a conventional spectrofluorometer. These results suggest that the printed photonic crystal offers a great potential for highly sensitive intercalator-based fluorescent detection of DNAs. (author)

Photochemical products causing fluorescence enhancement for 6H-benzo[cd]pyren-6-one in de-aerated and pre-irradiated solutions

Energy Technology Data Exchange (ETDEWEB)

Yagishita, M., E-mail: yagishita.mayuko@nies.go.jp [Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan); National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-City, Ibaraki 305-8506 (Japan); Nakajima, D. [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-City, Ibaraki 305-8506 (Japan); Ohshima, S. [Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan)

2016-11-15

Polycyclic aromatic ketones emit very weak fluorescence, but their fluorescence is significantly enhanced by about one hundred times after preliminary irradiation of their degassed solution. To investigate the mechanism of such fluorescence enhancement, liquid chromatography/time-of-flight mass spectrometry measurements were performed for degassed methanol, ethanol, and acetonitrile solutions of 6H-benzo[cd]pyren-6-one (naphthanthrone), in which fluorescence enhancement had been induced. As a result, two kinds of photochemical products were identified as the substance causing fluorescence enhancement: they were produced by dehydrogenation and dehydration of adducts of a solvent molecule to naphthanthrone. On the basis of the findings, the mechanism of the fluorescence enhancement of naphthanthrone was discussed. Fluorescence enhancement; 6H-benzo[cd]pyren-6-one; Polycyclic aromatic ketones; Liquid chromatography-mass spectrometry; Photochemical reaction.

Photochemical products causing fluorescence enhancement for 6H-benzo[cd]pyren-6-one in de-aerated and pre-irradiated solutions

International Nuclear Information System (INIS)

Yagishita, M.; Nakajima, D.; Ohshima, S.

2016-01-01

Polycyclic aromatic ketones emit very weak fluorescence, but their fluorescence is significantly enhanced by about one hundred times after preliminary irradiation of their degassed solution. To investigate the mechanism of such fluorescence enhancement, liquid chromatography/time-of-flight mass spectrometry measurements were performed for degassed methanol, ethanol, and acetonitrile solutions of 6H-benzo[cd]pyren-6-one (naphthanthrone), in which fluorescence enhancement had been induced. As a result, two kinds of photochemical products were identified as the substance causing fluorescence enhancement: they were produced by dehydrogenation and dehydration of adducts of a solvent molecule to naphthanthrone. On the basis of the findings, the mechanism of the fluorescence enhancement of naphthanthrone was discussed. Fluorescence enhancement; 6H-benzo[cd]pyren-6-one; Polycyclic aromatic ketones; Liquid chromatography-mass spectrometry; Photochemical reaction

Protein assisted fluorescence enhancement of a dansyl containing fluorescent reagent: detection of Hg+ ion in aqueous medium.

Science.gov (United States)

Srivastava, Priyanka; Shahid, Mohammad; Misra, Arvind

2011-07-21

Intramolecular charge transfer (ICT) based fluorescent reagents containing a dansyl fluorophore have been synthesized and characterized. The reagent 1 and its complex, 1+Hg(2+) in sodium acetate buffer (pH 6.7) revealed considerable fluorescence enhancement (switched-on) in the presence of bovine serum albumin (BSA) with 10 ppb detection sensitivity. (1)H NMR spectral analysis suggests complexation between 1 and Hg(2+) ion involving the N,N-dimethylamino and carboxylic functions.

Comparison of Au and Ag nanoshells' metal-enhanced fluorescence

International Nuclear Information System (INIS)

Liaw, Jiunn-Woei; Chen, Huang-Chih; Kuo, Mao-Kuen

2014-01-01

The average enhancement factors of Au and Ag nanoshells (NSs) were analyzed theoretically to compare their overall performances on metal-enhanced fluorescence. We used the Mie theory and dyadic Green's functions to calculate the excitation rate and apparent quantum yield of NS interacting with a plane wave and a dipole, respectively, and then to obtain the enhancement factor. Moreover, the average enhancement factor (AEF) of NS on the fluorescence of a nearby molecule was obtained by averaging all possible orientations and locations of the molecule with a constant distance from NS. Our results show that the maximum AEF of Au NS occurs at the wavelength of the dipole mode, which is broadband. In contrast, the maximum AEF of Ag NS is at the narrowband quadrupole mode. In addition, the Stokes shift effect on AEF was studied for Au and Ag NSs. - Highlights: • The average enhancement factors of Au and Ag nanoshells were analyzed theoretically. • The maximum AEF of Au NS occurs at the wavelength of the dipole mode. • The maximum AEF of Ag NS is at the narrowband quadrupole mode. • The Stokes shift effect on AEF is discussed for Au and Ag NSs

Video modeling by experts with video feedback to enhance gymnastics skills.

Science.gov (United States)

Boyer, Eva; Miltenberger, Raymond G; Batsche, Catherine; Fogel, Victoria

2009-01-01

The effects of combining video modeling by experts with video feedback were analyzed with 4 female competitive gymnasts (7 to 10 years old) in a multiple baseline design across behaviors. During the intervention, after the gymnast performed a specific gymnastics skill, she viewed a video segment showing an expert gymnast performing the same skill and then viewed a video replay of her own performance of the skill. The results showed that all gymnasts demonstrated improved performance across three gymnastics skills following exposure to the intervention.

Poly(o-phenylenediamine) colloid-quenched fluorescent oligonucleotide as a probe for fluorescence-enhanced nucleic acid detection.

Science.gov (United States)

Tian, Jingqi; Li, Hailong; Luo, Yonglan; Wang, Lei; Zhang, Yingwei; Sun, Xuping

2011-02-01

In this Letter, we demonstrate that chemical oxidation polymerization of o-phenylenediamine (OPD) by potassium bichromate at room temperature results in the formation of submicrometer-scale poly(o-phenylenediamine) (POPD) colloids. Such colloids can absorb and quench dye-labeled single-stranded DNA (ssDNA) very effectively. In the presence of a target, a hybridization event occurs, which produces a double-stranded DNA (dsDNA) that detaches from the POPD surface, leading to recovery of dye fluorescence. With the use of an oligonucleotide (OND) sequence associated with human immunodeficiency virus (HIV) as a model system, we demonstrate the proof of concept that POPD colloid-quenched fluorescent OND can be used as a probe for fluorescence-enhanced nucleic acid detection with selectivity down to single-base mismatch.

Enhancing the control of force in putting by video game training.

Science.gov (United States)

Fery, Y A; Ponserre, S

2001-10-10

Even if golf video games provide no proprioceptive afferences on actual putting movement, they may give sufficient substitutive visual cues to enhance force control in this skill. It was hypothesized that this usefulness requires, however, two conditions: the video game must provide reliable demonstrations of actual putts, and the user must want to use the game to make progress in actual putting. Accordingly, a video game was selected on the basis of its fidelity to the real-world game. It allowed two different methods of adjusting the virtual player's putting force in order to hole a putt: an analogue method that consisted of focusing on the virtual player's movement and a symbolic method that consisted of focusing on the movement of a gauge on a scale representing the virtual player's putting force. The participants had to use one of these methods with either the intention of making progress in actual putting or in a second condition to simply enjoy the game. Results showed a positive transfer of video playing to actual putting skill for the learning group and also, to a lesser degree, for the enjoyment group; but only when they used the symbolic method. Results are discussed in the context of how vision may convey force cues in sports video games.

One-pot synthesis of gold nanoclusters with bright red fluorescence and good biorecognition abilities for visualization fluorescence enhancement detection of E. coli.

Science.gov (United States)

Liu, Jiali; Lu, Lili; Xu, Suying; Wang, Leyu

2015-03-01

A facile one-pot strategy was developed for the synthesis of lysozyme functionalized fluorescence gold nanoclusters (AuNCs). The lysozymes added to reduce Au(3+) ions and stabilize the AuNCs during the synthesis were coated on the AuNCs surface and retained their specific recognition ability for bacteria such as Escherichia coli (E. coli). Based on such ability, these AuNCs were specifically attached onto the surface of E. coli, which resulted in great red fluorescence enhancement. Nevertheless, the bovine serum albumin (BSA) stabilized AuNCs could not recognize E. coli and no fluorescence enhancement was observed. Upon the addition of E. coli, the red fluorescence intensity of lysozyme-AuNCs was enhanced linearly over the range of 2.4×10(4) -6.0×10(6) CFU/mL of E. coli with high sensitivity (LOD=2.0×10(4) CFU/mL, S/N=3). The visualization fluorescence evolution may enable the rapid and real-time detection of bacteria. This study may be extended to other functional proteins such as antibody, enzyme, and peptide functionalized nanoclusters while retaining the bioactivity of coating proteins and find wide applications in the fields of biochemistry and biomedicine. Copyright © 2014 Elsevier B.V. All rights reserved.

[Selected enhancement of different order stokes lines of SRS by using fluorescence of mixed dye solution].

Science.gov (United States)

Zuo, Hao-yi; Gao, Jie; Yang, Jing-guo

2007-03-01

A new method to enhance the intensity of the different orders of Stokes lines of SRS by using mixed dye fluorescence is reported. The Stokes lines from the second-order to the fifth-order of CCl4 were enhanced by the fluorescence of mixed R6G and RB solutions in different proportions of 20:2, 20:13 and 20:40 (R6g:Rb), respectively. It is considered that the Stokes lines from the second-order to the fifth-order are near the fluorescence peaks of the three mixed solutions, and far from the absorption peaks of R6g and Rb, so the enhancement effect dominates the absorption effect; as a result, these stokes lines are enhanced. On the contrary, the first-order stokes line is near the absorption peak of RB and far from the fluorescence peaks of the mixed solutions, which leads to the weakening of this stokes line. It is also reported that the first-order, the second-order and the third-order Stokes lines of benzene were enhanced by the fluorescence of mixed solutions of R6g and DCM with of different proportions. The potential application of this method is forecasted.

Selective recognition of monohydrogen phosphate by fluorescence enhancement of a new cerium complex

International Nuclear Information System (INIS)

Ganjali, Mohammad Reza; Hosseini, Morteza; Memari, Zahra; Faridbod, Farnoush; Norouzi, Parviz; Goldooz, Hassan; Badiei, Alireza

2011-01-01

Highlights: ► Finding a new fluorescent enhancing chemosensor for phosphate ions. ► Synthesis of a new complex (bis(8-hydroxy quinoline-5-solphonate) cerium(III) chloride (Ce(QS) 2 Cl)) as a practical fluorescent probe. ► Analysis of phosphate content in three kinds of fertilizers, mixed fertilizer (N–P–K), triple super phosphate (TSP), and single super phosphate (SSP) (from Zarrin Kood Co., Tehran, Iran). - Abstract: Bis(8-hydroxy quinoline-5-solphonate) cerium(III) chloride (Ce(QS) 2 Cl) (L) was synthesized and then used as a novel fluorescent sensor for anion recognition. Preliminarily study showed that fluorescence of L enhanced selectively in the presence of HPO 4 2− ion. This enhancement is attributed to a 1:1 complex formation between L and HPO 4 2− anion. The association constant of 1:1 complex of L-HPO 4 2− was calculated as 3.0 × 10 6 . Thus, L was utilized as a basis for a selective detection of HPO 4 2− anion in solution. The linear response range of the proposed fluorescent chemo-sensor covers a concentration range of HPO 4 2− from 3.3 × 10 −7 to 5.0 × 10 −6 mol L −1 with a detection limit of 2.5 × 10 −8 mol L −1 . L showed selective and sensitive fluorescence enhancement response toward HPO 4 2− ion in comparison with I 3 − , NO 3 − , CN − , CO 3 2− , Br − , Cl − , F − , H 2 PO 4 − and SO 4 2− ions. It was probably attributed to the higher stability of the inorganic complex between HPO 4 2− ion and L. The method was successfully applied for analysis of phosphate ions in some fertilizers samples.

ONLINE LEARNING: CAN VIDEOS ENHANCE LEARNING?

OpenAIRE

HAJHASHEMI, Karim; ANDERSON, Neil; JACKSON, Cliff; CALTABIANO, Nerina

2015-01-01

Highereducation lecturers integrate different media into their courses. Internet-basededucational video clips have gained prominence, as this media is perceived topromote deeper thought processes, communication and interaction among users,and makeclassroom content more diverse.This paper provides a literature overview of the increasing importance ofonline videos across all modes of instruction. It discusses a quantitative andqualitative research design that was used to assess on-line video pe...

Fluorescence enhancement of samarium complex co-doped with terbium complex in a poly(methyl methacrylate) matrix

International Nuclear Information System (INIS)

Jiu Hongfang; Zhang Lixin; Liu Guode; Fan Tao

2009-01-01

The fluorescence property of Sm(DBM) 3 phen- (DBM-dibenzoylmethide, phen-1,10-phenanthroline) and Tb(DBM) 3 phen-co-doped poly(methyl methacrylate) (PMMA) was investigated. The excitation, emission spectra and fluorescence lifetime of the co-doped samples were examined. In the co-doped samples, the luminescence intensities of Sm 3+ enhance with an increase of the Tb(DBM) 3 phen content and with a decrease of the Sm(DBM) 3 phen content. The reason for the fluorescence enhancement effect in the co-doped polymer is the intermolecular energy transfer. To give a vivid picture for this co-doped system, a model for the fluorescence enhancement of Sm(DBM) 3 phen- and Tb(DBM) 3 phen-co-doped PMMA is presented

Supramodal Enhancement of Auditory Perceptual and Cognitive Learning by Video Game Playing.

Science.gov (United States)

Zhang, Yu-Xuan; Tang, Ding-Lan; Moore, David R; Amitay, Sygal

2017-01-01

Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD) with the popular spatial visual-motor game Tetris played in silence. Tetris play alone did not produce any auditory or cognitive benefits. However, when alternated with FD training it enhanced learning of FD and auditory working memory. The learning-enhancing effects of Tetris play cannot be explained simply by the visual-spatial training involved, as the effects were gone when Tetris play was replaced with another visual-spatial task using Tetris-like stimuli but not incorporated into a game environment. The results indicate that game play enhances learning and transfer of the contiguous auditory experiences, pointing to a promising approach for increasing the efficiency and applicability of rehabilitative training.

Supramodal Enhancement of Auditory Perceptual and Cognitive Learning by Video Game Playing

Directory of Open Access Journals (Sweden)

Yu-Xuan Zhang

2017-06-01

Full Text Available Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD with the popular spatial visual-motor game Tetris played in silence. Tetris play alone did not produce any auditory or cognitive benefits. However, when alternated with FD training it enhanced learning of FD and auditory working memory. The learning-enhancing effects of Tetris play cannot be explained simply by the visual-spatial training involved, as the effects were gone when Tetris play was replaced with another visual-spatial task using Tetris-like stimuli but not incorporated into a game environment. The results indicate that game play enhances learning and transfer of the contiguous auditory experiences, pointing to a promising approach for increasing the efficiency and applicability of rehabilitative training.

Fluorescence Enhancement on Large Area Self-Assembled Plasmonic-3D Photonic Crystals.

Science.gov (United States)

Chen, Guojian; Wang, Dongzhu; Hong, Wei; Sun, Lu; Zhu, Yongxiang; Chen, Xudong

2017-03-01

Discontinuous plasmonic-3D photonic crystal hybrid structures are fabricated in order to evaluate the coupling effect of surface plasmon resonance and the photonic stop band. The nanostructures are prepared by silver sputtering deposition on top of hydrophobic 3D photonic crystals. The localized surface plasmon resonance of the nanostructure has a symbiotic relationship with the 3D photonic stop band, leading to highly tunable characteristics. Fluorescence enhancements of conjugated polymer and quantum dot based on these hybrid structures are studied. The maximum fluorescence enhancement for the conjugated polymer of poly(5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene) potassium salt by a factor of 87 is achieved as compared with that on a glass substrate due to the enhanced near-field from the discontinuous plasmonic structures, strong scattering effects from rough metal surface with photonic stop band, and accelerated decay rates from metal-coupled excited state of the fluorophore. It is demonstrated that the enhancement induced by the hybrid structures has a larger effective distance (optimum thickness ≈130 nm) than conventional plasmonic systems. It is expected that this approach has tremendous potential in the field of sensors, fluorescence-imaging, and optoelectronic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distance-dependent metal enhanced fluorescence by flowerlike silver nanostructures fabricated in liquid crystalline phase

Science.gov (United States)

Zhang, Ying; Yang, Chengliang; Zhang, Guiyang; Peng, Zenghui; Yao, Lishuang; Wang, Qidong; Cao, Zhaoliang; Mu, Quanquan; Xuan, Li

2017-10-01

Flowerlike silver nanostructure substrates were fabricated in liquid crystalline phase and the distance dependent property of metal enhanced fluorescence for such substrate was studied for the first time. The distance between silver nanostructures and fluorophore was controlled by the well-established layer-by-layer (LbL) technique constructing alternate layers of poly (allylamine hydrochloride) (PAH) and poly (sodium 4-styrenesulfonate) (PSS). The Rhodamine 6G (R6G) molecules were electrostatically attached to the outmost negative charged PSS layer. The fluorescence enhancement factor of flowerlike nanostructure substrate increased firstly and then decreased with the distance increasing. The best enhanced fluorescence intensity of 71 fold was obtained at a distance of 5.2 nm from the surface of flowerlike silver nanostructure. The distance for best enhancement effect is an instructive parameter for the applications of such substrates and could be used in the practical MEF applications with the flowerlike nanostructure substrates fabricated in such way which is simple, controllable and cost-effective.

Learning from Errors in Dual Vocational Education: Video-Enhanced Instructional Strategies

Science.gov (United States)

Cattaneo, Alberto A. P.; Boldrini, Elena

2017-01-01

Purpose: Starting from the identification of some theoretically driven instructional principles, this paper presents a set of empirical cases based on strategies to learn from errors. The purpose of this paper is to provide first evidence about the feasibility and the effectiveness for learning of video-enhanced error-based strategies in…

Using the CPU and GPU for real-time video enhancement on a mobile computer

CSIR Research Space (South Africa)

Bachoo, AK

2010-09-01

Full Text Available . In this paper, the current advances in mobile CPU and GPU hardware are used to implement video enhancement algorithms in a new way on a mobile computer. Both the CPU and GPU are used effectively to achieve realtime performance for complex image enhancement...

Time variation of fluorescence lifetime in enhanced cyan fluorescence protein

International Nuclear Information System (INIS)

Lee, Soonhyouk; Kim, Soo Yong; Park, Kyoungsook; Jeong, Jinyoung; Chung, Bong Hyun; Kim, Sok Won

2010-01-01

The lifetime variations of enhanced cyan fluorescence protein (ECFP) in relatively short integration time bins were studied via time-correlated single photon counting (TCSPC) measurement. We observed that minimum photon counts are necessary for the lifetime estimation to achieve a certain range of variance. The conditions to decrease the variance of lifetime were investigated and the channel width of the measurement of TCSPC data was found to be another important factor for the variance of lifetime. Though the lifetime of ECFP is best fit by a double exponential, a mono exponential fit for the same integration time is more stable. The results may be useful in the analysis of photophysical dynamics for ensemble molecules in short measurement time windows.

Bulky Counterions: Enhancing the Two-Photon Excited Fluorescence of Gold Nanoclusters.

Science.gov (United States)

Bertorelle, Franck; Moulin, Christophe; Soleilhac, Antonin; Comby-Zerbino, Clothilde; Dugourd, Philippe; Russier-Antoine, Isabelle; Brevet, Pierre-François; Antoine, Rodolphe

2018-01-19

Increasing fluorescence quantum yields of ligand-protected gold nanoclusters has attracted wide research interest. The strategy consisting in using bulky counterions has been found to dramatically enhance the fluorescence. In this Communication, we push forward this concept to the nonlinear optical regime. We show that by an appropriate choice of bulky counterions and of solvent, a 30-fold increase in two-photon excited fluorescence (TPEF) signal at ≈600 nm for gold nanoclusters can be obtained. This would correspond to a TPEF cross-section in the range of 0.1 to 1 GM. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thousand-fold enhancement of single-molecule fluorescence near a single gold nanorod

NARCIS (Netherlands)

Yuan, H.; Khatua, S.; Zijlstra, P.; Yorulmaz, M.; Orrit, M.

2013-01-01

Single molecules: Large enhancements of single-molecule fluorescence up to 1100 times by using synthesized gold nanorods are reported (see picture). This high enhancement is achieved by selecting a dye with its adsorption and emission close to the surface plasmon resonance of the gold nanorods

Vocabulary Learning through Viewing Video: The Effect of Two Enhancement Techniques

Science.gov (United States)

Montero Perez, Maribel; Peters, Elke; Desmet, Piet

2018-01-01

While most studies on L2 vocabulary learning through input have addressed learners' vocabulary uptake from written text, this study focuses on audio-visual input. In particular, we investigate the effects of enhancing video by (1) adding different types of L2 subtitling (i.e. no captioning, full captioning, keyword captioning, and glossed keyword…

A PDMS-based cylindrical hybrid lens for enhanced fluorescence detection in microfluidic systems.

Science.gov (United States)

Lin, Bor-Shyh; Yang, Yu-Ching; Ho, Chong-Yi; Yang, Han-Yu; Wang, Hsiang-Yu

2014-02-13

Microfluidic systems based on fluorescence detection have been developed and applied for many biological and chemical applications. Because of the tiny amount of sample in the system; the induced fluorescence can be weak. Therefore, most microfluidic systems deploy multiple optical components or sophisticated equipment to enhance the efficiency of fluorescence detection. However, these strategies encounter common issues of complex manufacturing processes and high costs. In this study; a miniature, cylindrical and hybrid lens made of polydimethylsiloxane (PDMS) to improve the fluorescence detection in microfluidic systems is proposed. The hybrid lens integrates a laser focusing lens and a fluorescence collecting lens to achieve dual functions and simplify optical setup. Moreover, PDMS has advantages of low-cost and straightforward fabrication compared with conventional optical components. The performance of the proposed lens is first examined with two fluorescent dyes and the results show that the lens provides satisfactory enhancement for fluorescence detection of Rhodamine 6G and Nile Red. The overall increments in collected fluorescence signal and detection sensitivity are more than 220% of those without lens, and the detection limits of Rhodamine 6G and Nile red are lowered to 0.01 μg/mL and 0.05 μg/mL, respectively. The hybrid lens is further applied to the detection of Nile red-labeled Chlorella vulgaris cells and it increases both signal intensity and detection sensitivity by more than 520%. The proposed hybrid lens also dramatically reduces the variation in detected signal caused by the deviation in incident angle of excitation light.

High-quality substrate for fluorescence enhancement using agarose-coated silica opal film.

Science.gov (United States)

Xu, Ming; Li, Juan; Sun, Liguo; Zhao, Yuanjin; Xie, Zhuoying; Lv, Linli; Zhao, Xiangwei; Xiao, Pengfeng; Hu, Jing; Lv, Mei; Gu, Zhongze

2010-08-01

To improve the sensitivity of fluorescence detection in biochip, a new kind of substrates was developed by agarose coating on silica opal film. In this study, silica opal film was fabricated on glass substrate using the vertical deposition technique. It can provide stronger fluorescence signals and thus improve the detection sensitivity. After coating with agarose, the hybrid film could provide a 3D support for immobilizing sample. Comparing with agarose-coated glass substrate, the agarose-coated opal substrates could selectively enhance particular fluorescence signals with high sensitivity when the stop band of the silica opal film in the agarose-coated opal substrate overlapped the fluorescence emission wavelength. A DNA hybridization experiment demonstrated that fluorescence intensity of special type of agarose-coated opal substrates was about four times that of agarose-coated glass substrate. These results indicate that the optimized agarose-coated opal substrate can be used for improving the sensitivity of fluorescence detection with high quality and selectivity.

Enhanced change detection performance reveals improved strategy use in avid action video game players.

Science.gov (United States)

Clark, Kait; Fleck, Mathias S; Mitroff, Stephen R

2011-01-01

Recent research has shown that avid action video game players (VGPs) outperform non-video game players (NVGPs) on a variety of attentional and perceptual tasks. However, it remains unknown exactly why and how such differences arise; while some prior research has demonstrated that VGPs' improvements stem from enhanced basic perceptual processes, other work indicates that they can stem from enhanced attentional control. The current experiment used a change-detection task to explore whether top-down strategies can contribute to VGPs' improved abilities. Participants viewed alternating presentations of an image and a modified version of the image and were tasked with detecting and localizing the changed element. Consistent with prior claims of enhanced perceptual abilities, VGPs were able to detect the changes while requiring less exposure to the change than NVGPs. Further analyses revealed this improved change detection performance may result from altered strategy use; VGPs employed broader search patterns when scanning scenes for potential changes. These results complement prior demonstrations of VGPs' enhanced bottom-up perceptual benefits by providing new evidence of VGPs' potentially enhanced top-down strategic benefits. Copyright © 2010 Elsevier B.V. All rights reserved.

pH-Responsive Fluorescence Enhancement in Graphene Oxide-Naphthalimide Nanoconjugates: A Fluorescence Turn-On Sensor for Acetylcholine.

Science.gov (United States)

Mangalath, Sreejith; Abraham, Silja; Joseph, Joshy

2017-08-22

A pH-sensitive, fluorescence "turn-on" sensor based on a graphene oxide-naphthalimide (GO-NI) nanoconjugate for the detection of acetylcholine (ACh) by monitoring the enzymatic activity of acetylcholinesterase (AChE) in aqueous solution is reported. These nanoconjugates were synthesized by covalently anchoring picolyl-substituted NI derivatives on the GO/reduced GO surface through a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide coupling strategy, and the morphological and photophysical properties were studied in detail. Synergistic effects of π-π interactions between GO and the NI chromophore, and efficient photoinduced electron- and energy-transfer processes, were responsible for the strong quenching of fluorescence of these nanoconjugates, which were perturbed under acidic pH conditions, leading to significant enhancement of fluorescence emission. This nanoconjugate was successfully employed for the efficient sensing of pH changes caused by the enzymatic activity of AChE, thereby demonstrating its utility as a fluorescence turn-on sensor for ACh in the neurophysiological range. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Augmented video viewing: transforming video consumption into an active experience

OpenAIRE

WIJNANTS, Maarten; Leën, Jeroen; QUAX, Peter; LAMOTTE, Wim

2014-01-01

Traditional video productions fail to cater to the interactivity standards that the current generation of digitally native customers have become accustomed to. This paper therefore advertises the \\activation" of the video consumption process. In particular, it proposes to enhance HTML5 video playback with interactive features in order to transform video viewing into a dynamic pastime. The objective is to enable the authoring of more captivating and rewarding video experiences for end-users. T...

Rate control scheme for consistent video quality in scalable video codec.

Science.gov (United States)

Seo, Chan-Won; Han, Jong-Ki; Nguyen, Truong Q

2011-08-01

Multimedia data delivered to mobile devices over wireless channels or the Internet are complicated by bandwidth fluctuation and the variety of mobile devices. Scalable video coding has been developed as an extension of H.264/AVC to solve this problem. Since scalable video codec provides various scalabilities to adapt the bitstream for the channel conditions and terminal types, scalable codec is one of the useful codecs for wired or wireless multimedia communication systems, such as IPTV and streaming services. In such scalable multimedia communication systems, video quality fluctuation degrades the visual perception significantly. It is important to efficiently use the target bits in order to maintain a consistent video quality or achieve a small distortion variation throughout the whole video sequence. The scheme proposed in this paper provides a useful function to control video quality in applications supporting scalability, whereas conventional schemes have been proposed to control video quality in the H.264 and MPEG-4 systems. The proposed algorithm decides the quantization parameter of the enhancement layer to maintain a consistent video quality throughout the entire sequence. The video quality of the enhancement layer is controlled based on a closed-form formula which utilizes the residual data and quantization error of the base layer. The simulation results show that the proposed algorithm controls the frame quality of the enhancement layer in a simple operation, where the parameter decision algorithm is applied to each frame.

Fluorescence enhancing under UV-NIR simultaneous-excitation in ZnS:Cu,Mn phosphors

Directory of Open Access Journals (Sweden)

L. J. Xie

2012-12-01

Full Text Available The fluorescence properties of a long-lasting phosphor, ZnS:Cu,Mn was studied for the first time under simultaneously excitation of both UV and NIR light. Up to 20% fluorescence enhancement of the phosphor was observed. In the present simultaneously-excitation process, broad-band NIR light was absorbed and converted to visible photons via a single-photon upconversion path. We propose that a novel kind of spectral-conversion material with the unique ability to simultaneously convert both UV and NIR photons can be developed and is promising in the application of enhancing the EQE of solar cells.

Video denoising, deblocking, and enhancement through separable 4-D nonlocal spatiotemporal transforms.

Science.gov (United States)

Maggioni, Matteo; Boracchi, Giacomo; Foi, Alessandro; Egiazarian, Karen

2012-09-01

We propose a powerful video filtering algorithm that exploits temporal and spatial redundancy characterizing natural video sequences. The algorithm implements the paradigm of nonlocal grouping and collaborative filtering, where a higher dimensional transform-domain representation of the observations is leveraged to enforce sparsity, and thus regularize the data: 3-D spatiotemporal volumes are constructed by tracking blocks along trajectories defined by the motion vectors. Mutually similar volumes are then grouped together by stacking them along an additional fourth dimension, thus producing a 4-D structure, termed group, where different types of data correlation exist along the different dimensions: local correlation along the two dimensions of the blocks, temporal correlation along the motion trajectories, and nonlocal spatial correlation (i.e., self-similarity) along the fourth dimension of the group. Collaborative filtering is then realized by transforming each group through a decorrelating 4-D separable transform and then by shrinkage and inverse transformation. In this way, the collaborative filtering provides estimates for each volume stacked in the group, which are then returned and adaptively aggregated to their original positions in the video. The proposed filtering procedure addresses several video processing applications, such as denoising, deblocking, and enhancement of both grayscale and color data. Experimental results prove the effectiveness of our method in terms of both subjective and objective visual quality, and show that it outperforms the state of the art in video denoising.

The new fluorescence enhancement system Eu3+-ARADE-HMTM-AI3+ and its analytical application

International Nuclear Information System (INIS)

Wenwu Quin; Weisheng Liu; Tianlin Yang

2004-01-01

A new bis-Schiff base ligand, N,N -bis-(4-N-aminothiourea-2-amylidene)-4,4 -diaminodiphenyl ether (ARADE), was synthesized. Its complex with Eu 3+ in DMF emits the intrinsic fluorescence of Eu 3+ . The fluorescence intensity of the Eu 3+ -ARADE system was enhanced about 60-fold by the addition of hexamethylene tetramine (NMTM) and potash alum. This is a new fluorescence enhancement phenomenon. The excitation and emission wavelengths are 375 nm and 615 nm, respectively. Under optimal conditions, the fluorescence intensities vary linearly with the concentration of Eu 3+ in the range of 7.8x10 -9 -1.75x10 -5 mol L -1 with a detection limit of 5.2x10 -9 mol L -1 , or with the concentration of Al 3+ in the range of 3.1x10 -7 -9.7x10 -5 mol-L -1 with a detection limit of 2.7x10 -7 mol L -1 . The interferences of some rare earth metals and other inorganic ions were described. This method was applied to the determination of Eu 3+ in high purity yttrium oxide and the analysis of AI 3+ in alloy steel standard samples. The mechanism of fluorescence enhancement was also studied. (author)

Low-complexity JPEG-based progressive video codec for wireless video transmission

DEFF Research Database (Denmark)

Ukhanova, Ann; Forchhammer, Søren

2010-01-01

This paper discusses the question of video codec enhancement for wireless video transmission of high definition video data taking into account constraints on memory and complexity. Starting from parameter adjustment for JPEG2000 compression algorithm used for wireless transmission and achieving...

Video game training enhances cognitive control in older adults.

Science.gov (United States)

Anguera, J A; Boccanfuso, J; Rintoul, J L; Al-Hashimi, O; Faraji, F; Janowich, J; Kong, E; Larraburo, Y; Rolle, C; Johnston, E; Gazzaley, A

2013-09-05

Cognitive control is defined by a set of neural processes that allow us to interact with our complex environment in a goal-directed manner. Humans regularly challenge these control processes when attempting to simultaneously accomplish multiple goals (multitasking), generating interference as the result of fundamental information processing limitations. It is clear that multitasking behaviour has become ubiquitous in today's technologically dense world, and substantial evidence has accrued regarding multitasking difficulties and cognitive control deficits in our ageing population. Here we show that multitasking performance, as assessed with a custom-designed three-dimensional video game (NeuroRacer), exhibits a linear age-related decline from 20 to 79 years of age. By playing an adaptive version of NeuroRacer in multitasking training mode, older adults (60 to 85 years old) reduced multitasking costs compared to both an active control group and a no-contact control group, attaining levels beyond those achieved by untrained 20-year-old participants, with gains persisting for 6 months. Furthermore, age-related deficits in neural signatures of cognitive control, as measured with electroencephalography, were remediated by multitasking training (enhanced midline frontal theta power and frontal-posterior theta coherence). Critically, this training resulted in performance benefits that extended to untrained cognitive control abilities (enhanced sustained attention and working memory), with an increase in midline frontal theta power predicting the training-induced boost in sustained attention and preservation of multitasking improvement 6 months later. These findings highlight the robust plasticity of the prefrontal cognitive control system in the ageing brain, and provide the first evidence, to our knowledge, of how a custom-designed video game can be used to assess cognitive abilities across the lifespan, evaluate underlying neural mechanisms, and serve as a powerful tool

Metal Enhanced Fluorescence on Super-Hydrophobic Clusters of Gold Nanoparticles

KAUST Repository

Battista, Edmondo; Coluccio, Maria Laura; Alabastri, Alessandro; Barberio, Marianna; Causa, Filippo; Netti, Paolo Antonio; Di Fabrizio, Enzo M.; Gentile, Francesco

2016-01-01

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

Metal Enhanced Fluorescence on Super-Hydrophobic Clusters of Gold Nanoparticles

KAUST Repository

Battista, Edmondo

2016-12-15

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

Enhancing visuospatial performance through video game training to increase learning in visuospatial science domains.

Science.gov (United States)

Sanchez, Christopher A

2012-02-01

Although previous research has demonstrated that performance on visuospatial assessments can be enhanced through relevant experience, an unaddressed question is whether such experience also produces a similar increase in target domains (such as science learning) where visuospatial abilities are directly relevant for performance. In the present study, participants completed either spatial or nonspatial training via interaction with video games and were then asked to read and learn about the geologic topic of plate tectonics. Results replicate the benefit of playing appropriate video games in enhancing visuospatial performance and demonstrate that this facilitation also manifests itself in learning science topics that are visuospatial in nature. This novel result suggests that visuospatial training not only can impact performance on measures of spatial functioning, but also can affect performance in content areas in which these abilities are utilized.

Enhancing Security and Privacy in Video Surveillance through Role-Oriented Access Control Mechanism

DEFF Research Database (Denmark)

Mahmood Rajpoot, Qasim

sensitive regions, e.g. faces, from the videos. However, very few research efforts have focused on addressing the security aspects of video surveillance data and on authorizing access to this data. Interestingly, while PETs help protect the privacy of individuals, they may also hinder the usefulness....... Pervasive usage of such systems gives substantial powers to those monitoring the videos and poses a threat to the privacy of anyone observed by the system. Aside from protecting privacy from the outside attackers, it is equally important to protect the privacy of individuals from the inside personnel...... involved in monitoring surveillance data to minimize the chances of misuse of the system, e.g. voyeurism. In this context, several techniques to protect the privacy of individuals, called privacy enhancing techniques (PET) have therefore been proposed in the literature which detect and mask the privacy...

Student-Designed Public Service Announcement (PSA) Videos to Enhance Motivation and Engagement

Science.gov (United States)

Abrams, Kenneth

2012-01-01

Educators often focus on enhancing student motivation and engagement. This article describes an activity with these aims, in which undergraduates (a) learn about theories and research on means of persuasion and (b) in small groups design and record a public service announcement (PSA) video, write a brief paper that outlines the theories used to…

Increased fluorescence of PbS quantum dots in photonic crystals by excitation enhancement

Science.gov (United States)

Barth, Carlo; Roder, Sebastian; Brodoceanu, Daniel; Kraus, Tobias; Hammerschmidt, Martin; Burger, Sven; Becker, Christiane

2017-07-01

We report on the enhanced fluorescence of lead sulfide quantum dots interacting with leaky modes of slab-type silicon photonic crystals. The photonic crystal slabs were fabricated, supporting leaky modes in the near infrared wavelength range. Lead sulfite quantum dots which are resonant in the same spectral range were prepared in a thin layer above the slab. We selectively excited the leaky modes by tuning the wavelength and angle of incidence of the laser source and measured distinct resonances of enhanced fluorescence. By an appropriate experiment design, we ruled out directional light extraction effects and determined the impact of enhanced excitation. Three-dimensional numerical simulations consistently explain the experimental findings by strong near-field enhancements in the vicinity of the photonic crystal surface. Our study provides a basis for systematic tailoring of photonic crystals used in biological applications such as biosensing and single molecule detection, as well as quantum dot solar cells and spectral conversion applications.

Using tablet technology and instructional videos to enhance preclinical dental laboratory learning.

Science.gov (United States)

Gadbury-Amyot, Cynthia C; Purk, John H; Williams, Brian Joseph; Van Ness, Christopher J

2014-02-01

The purpose of this pilot study was to examine if tablet technology with accompanying instructional videos enhanced the teaching and learning outcomes in a preclinical dental laboratory setting. Two procedures deemed most challenging in Operative Dentistry II were chosen for the development of instructional videos. A random sample of thirty students was chosen to participate in the pilot. Comparison of faculty evaluations of the procedures between the experimental (tablet) and control (no tablet) groups resulted in no significant differences; however, there was a trend toward fewer failures in the experimental group. Examination of the ability to accurately self-assess was compared by exploring correlations between faculty and student evaluations. While correlations were stronger in the experimental group, the control group had significant correlations for all three procedures, while the experimental group had significant correlations on only two of the procedures. Students strongly perceived that the tablets and videos helped them perform better and more accurately self-assess their work products. Students did not support requiring that they purchase/obtain a specific brand of technology. As a result of this pilot study, further development of ideal and non-ideal videos are in progress, and the school will be implementing a "Bring Your Own Device" policy with incoming students.

Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles

Science.gov (United States)

Wang, Feng; Huang, Wei; Zhang, Shuai; Liu, Guokui; Li, Kexiang; Tang, Bo

2011-03-01

Ellagic acid (C 14H 6O 8), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0 × 10 -10 to 4.0 × 10 -5 mol L -1; and the detection limits are 3.2 × 10 -10 mol L -1 and 5.9 × 10 -10 mol L -1 excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

Effects of hyperthermia on intracellular CA/sup 2+/ monitored by digitized video image fluorescence microscopy

International Nuclear Information System (INIS)

Asher, C.R.; Mikkelsen, R.B.

1987-01-01

With digitized video image fluorescence microscopy and the fluorescent Ca/sup 2+/ dye, fuca-2, the authors examined heat effects on intracellular free Ca/sup 2+/, [Ca/sup 2/]/sub f/. HT-29 human colon cancer cells grown on coverslip were equilibrated with 2.0 μM fura-2 in RPMI 1540 (20 0 , 15 min), washed three times and incubated at 20 0 for 1 h. Coverslips were mounted in a Dvorok perfusion chamber sitting within a temperature controlled microscope stage. Fluorescence was monitored at 500 nm by epi-illumination at 385 nm, excitation maximum for free dye, and 340 nm, maximum for Ca/sup 2+/ complexed dye, with a computer controlled filter wheel. The emission intensity ratio, I/sub 340//I/sub 385/, which corrects for dye leakage, photo-bleaching and cell thickness was used to calculate [Ca/sup 2+/]/sub f/. Measurements of 200 cells at 37 0 using a bit pad and mouse to select 0.6 x 0.6 μ cytoplasmi areas indicated 3 populations of cells in terms of [Ca/sup 2+/]/sub f/ (70%, 40-60nM; 15% 70-110nM; 15%, 120-200 nM). Heating to 43 0 for 1 h resulted in an overall decrease in [Ca/sup 2+/]/sub f/ with greater than 90% cells within 30-50 nM. Not all cells responded to heat. Post-incubation for 3 h at 37 0 showed the identical cell distribution; at 24 h, cell distribution was that of non-heated cells. The relationship of these results to cell killing and thermotolerance are not understood, but these results indicated the importance of cell heterogeneity in response to heat

Fluorescence Enhancement Factors on Optical Antennas: Enlarging the Experimental Values without Changing the Antenna Design

Directory of Open Access Journals (Sweden)

Jérôme Wenger

2012-01-01

Full Text Available Plasmonic antennas offer promising opportunities to control the emission of quantum objects. As a consequence, the fluorescence enhancement factor is widely used as a figure of merit for a practical antenna realization. However, the fluorescence enhancement factor is not an intrinsic property of the antenna. It critically depends on several parameters, some of which are often disregarded. In this contribution, I explore the influence of the setup collection efficiency, emitter's quantum yield, and excitation intensity. Improperly setting these parameters may significantly alter the enhancement values, leading to potential misinterpretations. The discussion is illustrated by an antenna example of a nanoaperture surrounded by plasmonic corrugations.

Cognitive Enhancement Through Action Video Game Training: Great Expectations Require Greater Evidence

Directory of Open Access Journals (Sweden)

Joseph eBisoglio

2014-02-01

Full Text Available Action video game training may hold promise as a cognitive intervention with the potential to enhance daily functioning and remediate impairments, but this must be more thoroughly evaluated through evidence-based practices. We review current research on the effect of action video game training on visual attention and visuospatial processing, executive functions, and learning and memory. Focusing on studies that utilize strict experimental controls and synthesize behavioral and neurophysiological data, we examine whether there is sufficient evidence to support a causal relationship between action video game training and beneficial changes in cognition. Convergent lines of behavioral and neurophysiological evidence tentatively support the efficacy of training, but the magnitude and specificity of these effects remain obscure. Causal inference is thus far limited by a lack of standardized and well-controlled methodology. Considering future directions, we suggest stringent adherence to evidence based practices and collaboration modeled after clinical trial networks. Finally, we recommend the exploration of more complex causal models, such as indirect causal relationships and interactions that may be masking true effects.

Fluorescence-enhanced gadolinium-doped zinc oxide quantum dots for magnetic resonance and fluorescence imaging.

Science.gov (United States)

Liu, Yanlan; Ai, Kelong; Yuan, Qinghai; Lu, Lehui

2011-02-01

We report here the development of Gd-doped ZnO quantum dots (QDs) as dual modal fluorescence and magnetic resonance imaging nanoprobes. They are fabricated in a simple, versatile and environmentally friendly method, not only decreasing the difficulty and complexity, but also avoiding the increase of particle's size brought about by silica coating procedure in the synthesis of nanoprobes reported previously. These nanoprobes, with exceptionally small size and enhanced fluorescence resulting from the Gd doping, can label successfully the HeLa cells in short time and present no evidence of toxicity or adverse affect on cell growth even at the concentration up to 1 mm. These results show that such nanoprobes have low toxicity, especially in comparison with the traditional PEGylated CdSe/ZnS or CdSe/CdS QDs. In MRI studies, they exert strong positive contrast effect with a large longitudinal relaxivity (r(1)) of water proton of 16 mm(-1) s(-1). Their capability of imaging HeLa cells with MRI implies that they have great potential as MRI contrast agents. Combining the high sensitivity of fluorescence imaging with high spatial resolution of MRI, We expect that the as-prepared Gd-doped Zno QDs can provide a better reliability of the collected data and find promising applications in biological, medical and other fields. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparison of fluorescence-enhancing reagents and optimization of laser fluorimetric technique for the determination of dissolved uranium

International Nuclear Information System (INIS)

Ceren Kuetahyali; Joaquin Cobos; Rondinella, V.V.

2011-01-01

Results from tests aimed at optimizing an instrumental procedure for the direct and fast determination of uranium in solution by laser fluorescence are presented. A comparison of sample fluorescence measured using different fluorescence enhancing reagents was performed: sodium pyrophosphate, orthophosphoric acid, sulphuric acid and a commercially available fluorescence enhancer were tested for the determination of uranium. From the experimental results, 0.01 M Na 4 P 2 O 7 x 10H 2 O showed the best performance. Effects of reagent pH, different matrices, different concentrations of dissolved Th, and sample volume were investigated. Applications of the improved procedure for the determination of uranium in samples arising from UO 2 -based high level nuclear waste dissolution studies are described. (author)

Enhancement of single-molecule fluorescence signals by colloidal silver nanoparticles in studies of protein translation.

Science.gov (United States)

Bharill, Shashank; Chen, Chunlai; Stevens, Benjamin; Kaur, Jaskiran; Smilansky, Zeev; Mandecki, Wlodek; Gryczynski, Ignacy; Gryczynski, Zygmunt; Cooperman, Barry S; Goldman, Yale E

2011-01-25

Metal-enhanced fluorescence (MEF) increased total photon emission of Cy3- and Cy5-labeled ribosomal initiation complexes near 50 nm silver particles 4- and 5.5-fold, respectively. Fluorescence intensity fluctuations above shot noise, at 0.1-5 Hz, were greater on silver particles. Overall signal-to-noise ratio was similar or slightly improved near the particles. Proximity to silver particles did not compromise ribosome function, as measured by codon-dependent binding of fluorescent tRNA, dynamics of fluorescence resonance energy transfer between adjacent tRNAs in the ribosome, and tRNA translocation induced by elongation factor G.

Enhancement of Single Molecule Fluorescence Signals by Colloidal Silver Nanoparticles in Studies of Protein Translation

Science.gov (United States)

Bharill, Shashank; Chen, Chunlai; Stevens, Benjamin; Kaur, Jaskiran; Smilansky, Zeev; Mandecki, Wlodek; Gryczynski, Ignacy; Gryczynski, Zygmunt; Cooperman, Barry S.; Goldman, Yale E.

2011-01-01

Metal enhanced fluorescence (MEF) increased total photon emission of Cy3- and Cy5-labeled ribosomal initiation complexes near 50 nm silver particles 4- and 5.5-fold respectively. Fluorescence intensity fluctuations above shot noise, at 0.1 – 5 Hz, were greater on silver particles. Overall signal to noise ratio was similar or slightly improved near the particles. Proximity to silver particles did not compromise ribosome function, as measured by codon-dependent binding of fluorescent tRNA, dynamics of fluorescence resonance energy transfer between adjacent tRNAs in the ribosome, and tRNA translocation induced by elongation factor G. PMID:21158483

Enzyme-enhanced fluorescence detection of DNA on etched optical fibers.

Science.gov (United States)

Niu, Shu-yan; Li, Quan-yi; Ren, Rui; Zhang, Shu-sheng

2009-05-15

A novel DNA biosensor based on enzyme-enhanced fluorescence detection on etched optical fibers was developed. The hybridization complex of DNA probe and biotinylated target was formed on the etched optical fiber, and was then bound with streptavidin labeled horseradish peroxidase (streptavidin-HRP). The target DNA was quantified through the fluorescent detection of bi-p,p'-4-hydroxyphenylacetic acid (DBDA) generated from the substrate 4-hydroxyphenylacetic acid (p-HPA) under the catalysis of HRP, with a detection limit of 1 pM and a linear range from 1.69 pM to 169 pM. It is facile to regenerate this sensor through surface treatment with concentrated urea solution. It was discovered that the sensor can retain 70% of its original activity after three detection-regeneration cycles.

How nonlocal damping reduces plasmon-enhanced fluorescence in ultranarrow gaps [arXiv

DEFF Research Database (Denmark)

Tserkezis, Christos; Mortensen, N. Asger; Wubs, Martijn

2017-01-01

Nonclassical modifications of plasmon-assisted fluorescence enhancement are theoretically explored by placing dipole emitters at the narrow gaps encountered in canonical plasmonic architectures, namely dimers and trimers of different metallic nanoparticles. Through detailed simulations, in compar...... bounds to the enhancement feasible with ultrasmall plasmonic cavities, thus providing a theoretical description closer to state of the art experiments. [Phys. Rev. B 96, 085413 (2017) doi:10.1103/PhysRevB.96.085413]....

Enhancing the Therapy Experience Using Principles of Video Game Design.

Science.gov (United States)

Folkins, John Wm; Brackenbury, Tim; Krause, Miriam; Haviland, Allison

2016-02-01

This article considers the potential benefits that applying design principles from contemporary video games may have on enhancing therapy experiences. Six principles of video game design are presented, and their relevance for enriching clinical experiences is discussed. The motivational and learning benefits of each design principle have been discussed in the education literature as having positive impacts on student motivation and learning and are related here to aspects of clinical practice. The essential experience principle suggests connecting all aspects of the experience around a central emotion or cognitive connection. The discovery principle promotes indirect learning in focused environments. The risk-taking principle addresses the uncertainties clients face when attempting newly learned skills in novel situations. The generalization principle encourages multiple opportunities for skill transfer. The reward system principle directly relates to the scaffolding of frequent and varied feedback in treatment. Last, the identity principle can assist clients in using their newly learned communication skills to redefine self-perceptions. These principles highlight areas for research and interventions that may be used to reinforce or advance current practice.

High speed fluorescence imaging with compressed ultrafast photography

Science.gov (United States)

Thompson, J. V.; Mason, J. D.; Beier, H. T.; Bixler, J. N.

2017-02-01

Fluorescent lifetime imaging is an optical technique that facilitates imaging molecular interactions and cellular functions. Because the excited lifetime of a fluorophore is sensitive to its local microenvironment,1, 2 measurement of fluorescent lifetimes can be used to accurately detect regional changes in temperature, pH, and ion concentration. However, typical state of the art fluorescent lifetime methods are severely limited when it comes to acquisition time (on the order of seconds to minutes) and video rate imaging. Here we show that compressed ultrafast photography (CUP) can be used in conjunction with fluorescent lifetime imaging to overcome these acquisition rate limitations. Frame rates up to one hundred billion frames per second have been demonstrated with compressed ultrafast photography using a streak camera.3 These rates are achieved by encoding time in the spatial direction with a pseudo-random binary pattern. The time domain information is then reconstructed using a compressed sensing algorithm, resulting in a cube of data (x,y,t) for each readout image. Thus, application of compressed ultrafast photography will allow us to acquire an entire fluorescent lifetime image with a single laser pulse. Using a streak camera with a high-speed CMOS camera, acquisition rates of 100 frames per second can be achieved, which will significantly enhance our ability to quantitatively measure complex biological events with high spatial and temporal resolution. In particular, we will demonstrate the ability of this technique to do single-shot fluorescent lifetime imaging of cells and microspheres.

Soy flour-derived carbon dots: facile preparation, fluorescence enhancement, and sensitive Fe{sup 3+} detection

Energy Technology Data Exchange (ETDEWEB)

Fang, Liyang; Xu, Qian [China University of Petroleum, State Key Laboratory of Heavy Oil Processing (China); Zheng, Xing [Bei Jing Sinen En-Tech Co., Ltd (China); Zhang, Weina; Zheng, Jingtang, E-mail: jtzheng03@163.com; Wu, Mingbo, E-mail: wumb@upc.edu.cn; Wu, Wenting, E-mail: wuwt@upc.edu.cn [China University of Petroleum, State Key Laboratory of Heavy Oil Processing (China)

2016-08-15

Soy flour-derived carbon quantum dots (C-dots) were successfully synthesized via a facile one-step hydrothermal approach. The as-prepared C-dots exhibit an average diameter of 2.5 nm and the crystalline lattices are consistent with graphitic carbons. Meanwhile, they show strong photoluminescence (quantum yield is 7.85 %), good water solubility, and high photostability. Importantly, structural defects of the C-dots were designed to obtain controllable fluorescence, which was achieved by changing the contents of N defects and O defects of C-dots. Our results indicate that N defects can more effectively enhance the fluorescence emission than O defects. As the preparation temperature increases, the N defects are fine-tuned by substituting for partial O defects, reducing nonradiative recombination and enhancing fluorescence intensity, which is further confirmed by surface passivation. Due to its fine photostability, high sensitivity, and good selectivity for Fe{sup 3+}, the as-prepared C-dots were used as fluorescence probes for detection of ferric ion. The detection limitation comes to 0.021 µM.

Plasmonic properties and enhanced fluorescence of gold and dye-doped silica nanoparticle aggregates

Science.gov (United States)

Green, Nathaniel Scott

The development of metal-enhanced fluorescence has prompted a great interest in augmenting the photophysical properties of fluorescent molecules with noble metal nanostructures. Our research efforts, outlined in this dissertation, focus on augmenting properties of fluorophores by conjugation with gold nanostructures. The project goals are split into two separate efforts; the enhancement in brightness of fluorophores and long distance non-radiative energy transfer between fluorophores. We believe that interacting dye-doped silica nanoparticles with gold nanoparticles can facilitate both of these phenomena. Our primary research interest is focused on optimizing brightness, as this goal should open a path to studying the second goal of non-radiative energy transfer. The two major challenges to this are constructing suitable nanomaterials and functionalizing them to promote plasmonically active complexes. The synthesis of dye-doped layered silica nanoparticles allows for control over the discrete location of the dye and a substrate that can be surface functionalized. Controlling the exact location of the dye is important to create a silica spacer, which promotes productive interactions with metal nanostructures. Furthermore, the synthesis of silica nanoparticles allows for various fluorophores to be studied in similar environments (removing solvent and other chemo-sensitive issues). Functionalizing the surface of silica nanoparticles allows control over the degree of silica and gold nanoparticle aggregation in solution. Heteroaggregation in solution is useful for producing well-aggregated clusters of many gold around a single silica nanoparticle. The dye-doped surface functionalized silica nanoparticles can than be mixed efficiently with gold nanomaterials. Aggregating multiple gold nanospheres around a single dye-doped silica nanoparticle can dramatically increase the fluorescent brightness of the sample via metal-enhanced fluorescence due to increase plasmonic

A dual amplification strategy for DNA detection combining bio-barcode assay and metal-enhanced fluorescence modality.

Science.gov (United States)

Zhou, Zhenpeng; Li, Tian; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Chengzhi; Li, Na

2014-11-11

Silver-enhanced fluorescence was coupled with a bio-barcode assay to facilitate a dual amplification assay to demonstrate a non-enzymatic approach for simple and sensitive detection of DNA. In the assay design, magnetic nanoparticles seeded with silver nanoparticles were modified with the capture DNA, and silver nanoparticles were modified with the binding of ssDNA and the fluorescently labeled barcode dsDNA. Upon introduction of the target DNA, a sandwich structure was formed because of the hybridization reaction. By simple magnetic separation, silver-enhanced fluorescence of barcode DNAs could be readily measured without the need of a further step to liberate barcode DNAs from silver nanoparticles, endowing the method with simplicity and high sensitivity with a detection limit of 1 pM.

Nanograting-based plasmon enhancement for total internal reflection fluorescence microscopy of live cells

International Nuclear Information System (INIS)

Kim, Kyujung; Cho, Eun-Jin; Suh, Jin-Suck; Huh, Yong-Min; Kim, Donghyun; Kim, Dong Jun

2009-01-01

We investigated evanescent field enhancement based on subwavelength nanogratings for improved sensitivity in total internal reflection microscopy of live cells. The field enhancement is associated with subwavelength-grating-coupled plasmon excitation. An optimum sample employed a silver grating on a silver film and an SF10 glass substrate. Field intensity was enhanced by approximately 90% when measured by fluorescent excitation of microbeads relative to that on a bare prism as a control, which is in good agreement with numerical results. The subwavelength-grating-mediated field enhancement was also applied to live cell imaging of quantum dots, which confirmed the sensitivity enhancement qualitatively.

Learning Science Through Digital Video: Views on Watching and Creating Videos

Science.gov (United States)

Wade, P.; Courtney, A. R.

2013-12-01

In science, the use of digital video to document phenomena, experiments and demonstrations has rapidly increased during the last decade. The use of digital video for science education also has become common with the wide availability of video over the internet. However, as with using any technology as a teaching tool, some questions should be asked: What science is being learned from watching a YouTube clip of a volcanic eruption or an informational video on hydroelectric power generation? What are student preferences (e.g. multimedia versus traditional mode of delivery) with regard to their learning? This study describes 1) the efficacy of watching digital video in the science classroom to enhance student learning, 2) student preferences of instruction with regard to multimedia versus traditional delivery modes, and 3) the use of creating digital video as a project-based educational strategy to enhance learning. Undergraduate non-science majors were the primary focus group in this study. Students were asked to view video segments and respond to a survey focused on what they learned from the segments. Additionally, they were asked about their preference for instruction (e.g. text only, lecture-PowerPoint style delivery, or multimedia-video). A majority of students indicated that well-made video, accompanied with scientific explanations or demonstration of the phenomena was most useful and preferred over text-only or lecture instruction for learning scientific information while video-only delivery with little or no explanation was deemed not very useful in learning science concepts. The use of student generated video projects as learning vehicles for the creators and other class members as viewers also will be discussed.

Video Encryption and Decryption on Quantum Computers

Science.gov (United States)

Yan, Fei; Iliyasu, Abdullah M.; Venegas-Andraca, Salvador E.; Yang, Huamin

2015-08-01

A method for video encryption and decryption on quantum computers is proposed based on color information transformations on each frame encoding the content of the encoding the content of the video. The proposed method provides a flexible operation to encrypt quantum video by means of the quantum measurement in order to enhance the security of the video. To validate the proposed approach, a tetris tile-matching puzzle game video is utilized in the experimental simulations. The results obtained suggest that the proposed method enhances the security and speed of quantum video encryption and decryption, both properties required for secure transmission and sharing of video content in quantum communication.

Effective Educational Videos: Principles and Guidelines for Maximizing Student Learning from Video Content

Science.gov (United States)

Brame, Cynthia J.

2016-01-01

Educational videos have become an important part of higher education, providing an important content-delivery tool in many flipped, blended, and online classes. Effective use of video as an educational tool is enhanced when instructors consider three elements: how to manage cognitive load of the video; how to maximize student engagement with the video; and how to promote active learning from the video. This essay reviews literature relevant to each of these principles and suggests practical ways instructors can use these principles when using video as an educational tool. PMID:27789532

Enhancing conflict negotiation strategies of adolescents with autism spectrum disorder using video modeling.

Science.gov (United States)

Hochhauser, M; Weiss, P L; Gal, E

2018-01-01

Adolescents with autism spectrum disorder (ASD) have particular difficulty in negotiating conflict. A randomized control trial (RCT) was carried out to determine whether the negotiation strategies of adolescents with ASD would be enhanced via a 6-week intervention based on a video modeling application. Adolescents with ASD, aged 12-18 years, were randomly divided into an intervention group (n = 36) and a non-treatment control group (n = 25). Participants' negotiating strategies prior to and following the intervention were measured using the Five Factor Negotiation Scale (FFNS; Nakkula & Nikitopoulos, 1999) and the ConflicTalk questionnaire (Kimsey & Fuller, 2003). The results suggest that video modeling is an effective intervention for improving and maintaining conflict negotiation strategies of adolescents with ASD.

Laser scanning endoscope via an imaging fiber bundle for fluorescence imaging

Science.gov (United States)

Yeboah, Lorenz D.; Nestler, Dirk; Steiner, Rudolf W.

1994-12-01

Based on a laser scanning endoscope via an imaging fiber bundle, a new approach for a tumor diagnostic system has been developed to assist physicians in the diagnosis before the actual PDT is carried out. Laser induced, spatially resolved fluorescence images of diseased tissue can be compared with images received by video endoscopy using a white light source. The set- up is required to produce a better contrast between infected and healthy tissue and might serve as a constructive diagnostic help for surgeons. The fundamental idea is to scan a low-power laser beam on an imaging fiber bundle and to achieve a spatially resolved projection on the tissue surface. A sufficiently high laser intensity from the diode laser is concentrated on each single spot of the tissue exciting fluorescence when a dye has previously been accumulated. Subsequently, video image of the tissue is recorded and stored. With an image processing unit, video and fluorescence images are overlaid producing a picture of the fluorescence intensity in the environment of the observed tissue.

Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II)

Science.gov (United States)

Zhu, Jian; Chang, Hui; Li, Jian-Jun; Li, Xin; Zhao, Jun-Wu

2018-01-01

The effect of silicon-coated gold nanoparticles with different gold core diameter and silica shell thickness on the fluorescence emission of CdTe quantum dots (QDs) was investigated. For gold nanoparticles with a diameter of 15 nm, silica coating can only results in fluorescence recover of the bare gold nanoparticle-induced quenching of QDs. However, when the size of gold nanoparticle is increased to 60 nm, fluorescence enhancement of the QDs could be obtained by silica coating. Because of the isolation of the silica shell-reduced quenching effect and local electric field effect, the fluorescence of QDs gets intense firstly and then decreases. The maximum fluorescence enhancement takes place as the silica shell has a thickness of 30 nm. This enhanced fluorescence from silicon-coated gold nanoparticles is demonstrated for sensing of Hg2 +. Under optimal conditions, the enhanced fluorescence intensity decreases linearly with the concentration of Hg2 + ranging from 0 to 200 ng/mL. The limit of detection for Hg2 + is 1.25 ng/mL. Interference test and real samples detection indicate that the influence from other metal ions could be neglected, and the Hg2 + could be specifically detected.

DNA abasic site-selective enhancement of sanguinarine fluorescence with a large emission shift.

Directory of Open Access Journals (Sweden)

Fei Wu

Full Text Available Small molecules that can specifically bind to a DNA abasic site (AP site have received much attention due to their importance in DNA lesion identification, drug discovery, and sensor design. Herein, the AP site binding behavior of sanguinarine (SG, a natural alkaloid, was investigated. In aqueous solution, SG has a short-wavelength alkanolamine emission band and a long-wavelength iminium emission band. At pH 8.3, SG experiences a fluorescence quenching for both bands upon binding to fully matched DNAs without the AP site, while the presence of the AP site induces a strong SG binding and the observed fluorescence enhancement for the iminium band are highly dependent on the nucleobases flanking the AP site, while the alkanolamine band is always quenched. The bases opposite the AP site also exert some modifications on the SG's emission behavior. It was found that the observed quenching for DNAs with Gs and Cs flanking the AP site is most likely caused by electron transfer between the AP site-bound excited-state SG and the nearby Gs. However, the flanking As and Ts that are not easily oxidized favor the enhanced emission. This AP site-selective enhancement of SG fluorescence accompanies a band conversion in the dominate emission from the alkanolamine to iminium band thus with a large emission shift of about 170 nm. Absorption spectra, steady-state and transient-state fluorescence, DNA melting, and electrolyte experiments confirm that the AP site binding of SG occurs and the stacking interaction with the nearby base pairs is likely to prevent the converted SG iminium form from contacting with water that is thus emissive when the AP site neighbors are bases other than guanines. We expect that this fluorophore would be developed as a promising AP site binder having a large emission shift.

Effective and efficient learning in the operating theater with intraoperative video-enhanced surgical procedure training

NARCIS (Netherlands)

van Det, M.J.; Meijerink, W.J.; Hoff, C.; Middel, B.; Pierie, J.P.

INtraoperative Video Enhanced Surgical procedure Training (INVEST) is a new training method designed to improve the transition from basic skills training in a skills lab to procedural training in the operating theater. Traditionally, the master-apprentice model (MAM) is used for procedural training

Interacting with target tracking algorithms in a gaze-enhanced motion video analysis system

Science.gov (United States)

Hild, Jutta; Krüger, Wolfgang; Heinze, Norbert; Peinsipp-Byma, Elisabeth; Beyerer, Jürgen

2016-05-01

Motion video analysis is a challenging task, particularly if real-time analysis is required. It is therefore an important issue how to provide suitable assistance for the human operator. Given that the use of customized video analysis systems is more and more established, one supporting measure is to provide system functions which perform subtasks of the analysis. Recent progress in the development of automated image exploitation algorithms allow, e.g., real-time moving target tracking. Another supporting measure is to provide a user interface which strives to reduce the perceptual, cognitive and motor load of the human operator for example by incorporating the operator's visual focus of attention. A gaze-enhanced user interface is able to help here. This work extends prior work on automated target recognition, segmentation, and tracking algorithms as well as about the benefits of a gaze-enhanced user interface for interaction with moving targets. We also propose a prototypical system design aiming to combine both the qualities of the human observer's perception and the automated algorithms in order to improve the overall performance of a real-time video analysis system. In this contribution, we address two novel issues analyzing gaze-based interaction with target tracking algorithms. The first issue extends the gaze-based triggering of a target tracking process, e.g., investigating how to best relaunch in the case of track loss. The second issue addresses the initialization of tracking algorithms without motion segmentation where the operator has to provide the system with the object's image region in order to start the tracking algorithm.

Quantization of bovine serum albumin by fluorescence enhancement effects and corresponding binding of macrocyclic host-protein assembly.

Science.gov (United States)

Bardhan, Munmun; Misra, Tapas; Ganguly, Tapan

2012-01-05

The present paper reports the investigations on the spectroscopic behavior of the binary complexes of the dye aurintricarboxylic acid (ATA) with protein bovine serum albumin (BSA) and 18-crown 6 (CW) (ATA·BSA, ATA·CW) and the ternary complex ATA·CW·BSA by using UV-vis steady state and time resolved fluorescence spectroscopy. The primary aim of the work is to determine the protein (BSA) quantization by fluorescence enhancement method and investigate the 'enhancer' activity of crown ether (CW) on it to increase the resolution. Steady state and time resolved fluorescence measurements demonstrated how fluorescence intensity of ATA could be used for the determination of the protein BSA in aqueous solution. The binding of dye (probe/fluorescent medicinal molecule) with protein and the denaturing effect in the polar environment of acetonitrile of the dye protein complex act as drug binding as well as drug release activity. Apart from its basic research point of view, the present study also possesses significant importance and applications in the field of medicinal chemistry. Copyright © 2011 Elsevier B.V. All rights reserved.

Enhanced solid state emission of quinoline derivatives for fluorescent sensors

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyong-Jun, E-mail: hkim@kongju.ac.kr

2016-08-15

Excited-state intramolecular proton transfer (ESIPT) molecules are of utmost interest in the fields of organic light emitting diode, photo-patterning, chemosensor, proton transfer laser, and photostabilizer. Fine control of the functional substituents as well as the molecular structure of core ESIPT unit is primarily demanded for specific applications. Here, the photophysics of quinoline derivatives of 2-quinolin-2-yl-phenol and 2-(8-chloroquinolin-2-yl)phenol is explored. Straightening the twist between the hydroxyphenyl and the quinoline moieties with the aid of the hydrogen bonding promoted the excited energy to flow through a radiative decay pathway via proton transfer to the nitrogen. Furthermore, close molecular packing of J-aggregates and thus resulted vibration restriction in a dense matter opens an ESIPT corridor and is characterized to show enhanced emission. The mechanism is applied to the selective Cu{sup 2+} or Fe{sup 2+} cation detection and further immunofluorescence labeling using avidin–biotin protein specific binding is demonstrated with the aid of nano self-assembly technique. - Highlights: • New orange fluorescent hydroxyphenylquinoline derivative was synthesized. • Molecular structure planarization induced enhanced fluorescence with large Stokes' shift. • Selective solution phase cation detection and solid state bio-sensing were demonstrated successfully.

Video processing for human perceptual visual quality-oriented video coding.

Science.gov (United States)

Oh, Hyungsuk; Kim, Wonha

2013-04-01

We have developed a video processing method that achieves human perceptual visual quality-oriented video coding. The patterns of moving objects are modeled by considering the limited human capacity for spatial-temporal resolution and the visual sensory memory together, and an online moving pattern classifier is devised by using the Hedge algorithm. The moving pattern classifier is embedded in the existing visual saliency with the purpose of providing a human perceptual video quality saliency model. In order to apply the developed saliency model to video coding, the conventional foveation filtering method is extended. The proposed foveation filter can smooth and enhance the video signals locally, in conformance with the developed saliency model, without causing any artifacts. The performance evaluation results confirm that the proposed video processing method shows reliable improvements in the perceptual quality for various sequences and at various bandwidths, compared to existing saliency-based video coding methods.

Fluorescence imaging to quantify crop residue cover

Science.gov (United States)

Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.

1994-01-01

Crop residues, the portion of the crop left in the field after harvest, can be an important management factor in controlling soil erosion. Methods to quantify residue cover are needed that are rapid, accurate, and objective. Scenes with known amounts of crop residue were illuminated with long wave ultraviolet (UV) radiation and fluorescence images were recorded with an intensified video camera fitted with a 453 to 488 nm band pass filter. A light colored soil and a dark colored soil were used as background for the weathered soybean stems. Residue cover was determined by counting the proportion of the pixels in the image with fluorescence values greater than a threshold. Soil pixels had the lowest gray levels in the images. The values of the soybean residue pixels spanned nearly the full range of the 8-bit video data. Classification accuracies typically were within 3(absolute units) of measured cover values. Video imaging can provide an intuitive understanding of the fraction of the soil covered by residue.

Magnetic-Field Induced Enhancement in the Fluorescence Yield Spectrum of Doubly Excited States in Helium

International Nuclear Information System (INIS)

Stroem, Magnus; Saathe, Conny; Agaaker, Marcus; Soederstroem, Johan; Rubensson, Jan-Erik; Stranges, Stefano; Richter, Robert; Alagia, Michele; Gorczyca, T. W.; Robicheaux, F.

2006-01-01

An influence of static magnetic fields on the fluorescence yield spectrum of He in the vicinity of the N=2 thresholds has been observed. The experimental results are in excellent agreement with predictions based on multichannel quantum defect theory, and it is demonstrated that the Rydberg electron l mixing due to the diamagnetic interaction is essential for the description of the observed fluorescence yield intensity enhancement

Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

KAUST Repository

Aly, Shawkat Mohammede

2014-06-12

Fluorescence enhancement of organic fluorophores shows tremendous potential to improve image contrast in fluorescence-based bioimaging. Here, we present an experimental study of the interaction of two cationic porphyrins, meso-tetrakis(1-methylpyridinium-4-yl)porphyrin chloride (TMPyP) and meso-tetrakis(4-N,N,N-trimethylanilinium)porphyrin chloride (TMAP), with cationic surfactant-stabilized zinc oxide nanoparticles (ZnO NPs) based on several steady-state and time-resolved techniques. We show the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic porphyrins. For TMPyP, we observe a sixfold increase in the fluorescence intensity of TMPyP upon addition of ZnO NPs. Our experimental results indicate that the electrostatic binding of TMPyP with the surface of ZnO NPs increases the symmetry of the porphyrin macrocycle. This electronic communication hinders the rotational relaxation of the meso unit and/or decreases the intramolecular CT character between the cavity and the meso substituent of the porphyrin, resulting in the enhancement of the intensity of the fluorescence. For TMAP, on the other hand, the different type and nature of the positive charge resulting in the development of the CT band arise from the interaction with the surface of ZnO NPs. This observation is confirmed by the femtosecond transient absorption spectroscopy, which provides clear spectroscopic signatures of photoinduced electron transfer from TMAP to ZnO NPs. © 2014 American Chemical Society.

The Synthesis of Wavelength-Controlled CdTe/Hydroxyapatite Composites and Their Fluorescence Enhancement by Bovine Serum Albumin

Directory of Open Access Journals (Sweden)

Li Jin

2016-01-01

Full Text Available For the last ten years, quantum dots modified by biological materials have made it possible to study biochemical processes by means of biomedical imaging. This thesis introduced how the fluorescence CdTe quantum dots/hydroxyapatite composites were synthesized and how their structure, morphology, and fluorescence property were characterized by using TEM, XRD, EDS, UV-vis absorption spectra, and fluorescence spectra. The fluorescence spectra indicated the superb photometric characteristics of CdTe/HA composites. We also found that refluxing temperature and time had prominent effects on fluorescence wavelength and intensity of CdTe/HA composites, so the fluorescence emission wavelength of CdTe/HA composites could be controlled. In addition, the effect of BSA on the fluorescence properties of CdTe/HA composites was studied. The fluorescent emission intensity of CdTe/HA composites was enhanced directly with increasing concentrations of BSA; meanwhile, the fluorescence emission intensity of BSA dramatically decreased, which indicated that a Förster nonradiative energy transfer process occurred through the formation of chemical bonds between BSA and CdTe/HA composites. And the two-dimensional correlation (2D COS was used to analyze the BSA solution before and after the reaction, which indicated that CdTe/HA composites have bound to a site at the surface of the molecule in the first subdomain IA. We also found that there was a linear relationship between the fluorescence intensity enhancement (F/F0 of CdTe/HA composites and the concentration of the bovine serum albumin, which might become a method for quantitative analysis of BSA in a real sample.

Unequal Protection of Video Streaming through Adaptive Modulation with a Trizone Buffer over Bluetooth Enhanced Data Rate

Directory of Open Access Journals (Sweden)

Razavi Rouzbeh

2008-01-01

Full Text Available Abstract Bluetooth enhanced data rate wireless channel can support higher-quality video streams compared to previous versions of Bluetooth. Packet loss when transmitting compressed data has an effect on the delivered video quality that endures over multiple frames. To reduce the impact of radio frequency noise and interference, this paper proposes adaptive modulation based on content type at the video frame level and content importance at the macroblock level. Because the bit rate of protected data is reduced, the paper proposes buffer management to reduce the risk of buffer overflow. A trizone buffer is introduced, with a varying unequal protection policy in each zone. Application of this policy together with adaptive modulation results in up to 4 dB improvement in objective video quality compared to fixed rate scheme for an additive white Gaussian noise channel and around 10 dB for a Gilbert-Elliott channel. The paper also reports a consistent improvement in video quality over a scheme that adapts to channel conditions by varying the data rate without accounting for the video frame packet type or buffer congestion.

Unequal Protection of Video Streaming through Adaptive Modulation with a Trizone Buffer over Bluetooth Enhanced Data Rate

Directory of Open Access Journals (Sweden)

Rouzbeh Razavi

2007-12-01

Full Text Available Bluetooth enhanced data rate wireless channel can support higher-quality video streams compared to previous versions of Bluetooth. Packet loss when transmitting compressed data has an effect on the delivered video quality that endures over multiple frames. To reduce the impact of radio frequency noise and interference, this paper proposes adaptive modulation based on content type at the video frame level and content importance at the macroblock level. Because the bit rate of protected data is reduced, the paper proposes buffer management to reduce the risk of buffer overflow. A trizone buffer is introduced, with a varying unequal protection policy in each zone. Application of this policy together with adaptive modulation results in up to 4 dB improvement in objective video quality compared to fixed rate scheme for an additive white Gaussian noise channel and around 10 dB for a Gilbert-Elliott channel. The paper also reports a consistent improvement in video quality over a scheme that adapts to channel conditions by varying the data rate without accounting for the video frame packet type or buffer congestion.

Adaptive format conversion for scalable video coding

Science.gov (United States)

Wan, Wade K.; Lim, Jae S.

2001-12-01

The enhancement layer in many scalable coding algorithms is composed of residual coding information. There is another type of information that can be transmitted instead of (or in addition to) residual coding. Since the encoder has access to the original sequence, it can utilize adaptive format conversion (AFC) to generate the enhancement layer and transmit the different format conversion methods as enhancement data. This paper investigates the use of adaptive format conversion information as enhancement data in scalable video coding. Experimental results are shown for a wide range of base layer qualities and enhancement bitrates to determine when AFC can improve video scalability. Since the parameters needed for AFC are small compared to residual coding, AFC can provide video scalability at low enhancement layer bitrates that are not possible with residual coding. In addition, AFC can also be used in addition to residual coding to improve video scalability at higher enhancement layer bitrates. Adaptive format conversion has not been studied in detail, but many scalable applications may benefit from it. An example of an application that AFC is well-suited for is the migration path for digital television where AFC can provide immediate video scalability as well as assist future migrations.

Enhanced EGFP Fluorescence Emission in Presence of PEG Aqueous Solutions and PIB1000-PEG6000-PIB1000 Copolymer Vesicles

Directory of Open Access Journals (Sweden)

Noor Muhammad

2013-01-01

Full Text Available An EGFP construct interacting with the PIB1000-PEG6000-PIB1000 vesicles surface reported a ~2-fold fluorescence emission enhancement. Because of the constructs nature with the amphiphilic peptide inserted into the PIB core, EGFP is expected to experience a “pure” PEG environment. To unravel this phenomenon PEG/water solutions at different molecular weights and concentrations were used. Already at ~1 : 10 protein/PEG molar ratio the increase in fluorescence emission is observed reaching a plateau correlating with the PEG molecular weight. Parallel experiments in presence of glycerol aqueous solutions did show a slight fluorescence enhancement however starting at much higher concentrations. Molecular dynamics simulations of EGFP in neat water, glycerol, and PEG aqueous solutions were performed showing that PEG molecules tend to “wrap” the protein creating a microenvironment where the local PEG concentration is higher compared to its bulk concentration. Because the fluorescent emission can be perturbed by the refractive index surrounding the protein, the clustering of PEG molecules induces an enhanced fluorescence emission already at extremely low concentrations. These findings can be important when related to the use of EGFP as reported in molecular biology experiments.

Photostable bipolar fluorescent probe for video tracking plasma membranes related cellular processes.

Science.gov (United States)

Zhang, Xinfu; Wang, Chao; Jin, Liji; Han, Zhuo; Xiao, Yi

2014-08-13

Plasma membranes can sense the stimulations and transmit the signals from extracellular environment and then make further responses through changes in locations, shapes or morphologies. Common fluorescent membrane markers are not well suited for long time tracking due to their shorter retention time inside plasma membranes and/or their lower photostability. To this end, we develop a new bipolar marker, Mem-SQAC, which can stably insert into plasma membranes of different cells and exhibits a long retention time over 30 min. Mem-SQAC also inherits excellent photostability from the BODIPY dye family. Large two-photon absorption cross sections and long wavelength fluorescence emissions further enhance the competitiveness of Mem-SQAC as a membrane marker. By using Mem-SQAC, significant morphological changes of plasma membranes have been monitored during heavy metal poisoning and drug induced apoptosis of MCF-7 cells; the change tendencies are so distinctly different from each other that they can be used as indicators to distinguish different cell injuries. Further on, the complete processes of endocytosis toward Staphylococcus aureus and Escherichia coli by RAW 264.7 cells have been dynamically tracked. It is discovered that plasma membranes take quite different actions in response to the two bacteria, information unavailable in previous research reports.

Highly selective and sensitive detection of Cu2+ with lysine enhancing bovine serum albumin modified-carbon dots fluorescent probe.

Science.gov (United States)

Liu, Jia-Ming; Lin, Li-ping; Wang, Xin-Xing; Lin, Shao-Qin; Cai, Wen-Lian; Zhang, Li-Hong; Zheng, Zhi-Yong

2012-06-07

Based on the ability of lysine (Lys) to enhance the fluorescence intensity of bovine serum albumin modified-carbon dots (CDs-BSA) to decrease surface defects and quench fluorescence of the CDs-BSA-Lys system in the presence of Cu(2+) under conditions of phosphate buffer (PBS, pH = 5.0) at 45 °C for 10 min, a sensitive Lys enhancing CDs-BSA fluorescent probe was designed. The environment-friendly, simple, rapid, selective and sensitive fluorescent probe has been utilized to detect Cu(2+) in hair and tap water samples and it achieved consistent results with those obtained by inductively coupled plasma mass spectroscopy (ICP-MS). The mechanism of the proposed assay for the detection of Cu(2+) is discussed.

Highly Enhanced Fluorescence of CdSeTe Quantum Dots Coated with Polyanilines via In-Situ Polymerization and Cell Imaging Application.

Science.gov (United States)

Xue, Jingjing; Chen, Xinyi; Liu, Shanglin; Zheng, Fenfen; He, Li; Li, Lingling; Zhu, Jun-Jie

2015-09-02

The polyaniline (PAN)-coated CdSeTe quantum dots (QDs) were prepared by in situ polymerization of aniline on the surface of CdSeTe QDs. The PAN-coated CdSeTe QDs has a tremendously enhanced fluorescence (∼40 times) and improved biocompatibility compared to the uncoated CdSeTe QDs. The fluorescence intensity of the PAN-coated CdSeTe QDs can be adjusted by controlling the construction parameters of the PAN shell. The kinetics of the in situ controllable polymerization process was studied by varying the temperature, and the apparent activation energy of polymerization was estimated. With the same method, a series of the PAN derivatives were also tested to coat the CdSeTe QDs in this study. All the QDs showed a significant enhancement of the fluorescence intensity and better biocompatibility. The significantly enhanced fluorescence can provide highly amplified signal for luminescence-based cell imaging.

Enhanced fluorescence of a molecular dipole near metal nanoparticle

International Nuclear Information System (INIS)

Pustovit, Vitaliy N.

2010-01-01

We study theoretically radiative and nonradiative decay of a single molecule near small gold nanoparticle. The local field enhancement leads to an increased radiative decay rate while the energy transfer from molecule to optically inactive electronic states in nanoparticle results in a decrease in the fluorescence quantum efficiency for small molecule-nanoparticle distances. We performed a DFT-TDLDA calculation of both the enhancement and the quenching for small nanometersized gold nanoparticles. We found that in close proximity to the surface, the nonradiative decay rate is dominated by generation of electron-hole pairs out of the Fermi sea resulting in a significantly lower quantum efficiency as compared to that obtained from electromagnetic calculations. For large distances, the efficiency is maximal for molecule polarized normal to the surface, whereas for small distances it is maximal for parallel orientation.

Enhanced fluorescence of a molecular dipole near metal nanoparticle

Energy Technology Data Exchange (ETDEWEB)

Pustovit, Vitaliy N., E-mail: pustovit@ccmsi.u [Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, General Naumov Street 17, 03164 Kyiv-164 (Ukraine)

2010-01-15

We study theoretically radiative and nonradiative decay of a single molecule near small gold nanoparticle. The local field enhancement leads to an increased radiative decay rate while the energy transfer from molecule to optically inactive electronic states in nanoparticle results in a decrease in the fluorescence quantum efficiency for small molecule-nanoparticle distances. We performed a DFT-TDLDA calculation of both the enhancement and the quenching for small nanometersized gold nanoparticles. We found that in close proximity to the surface, the nonradiative decay rate is dominated by generation of electron-hole pairs out of the Fermi sea resulting in a significantly lower quantum efficiency as compared to that obtained from electromagnetic calculations. For large distances, the efficiency is maximal for molecule polarized normal to the surface, whereas for small distances it is maximal for parallel orientation.

Development of P4140 video data wall projector; Video data wall projector

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H.; Inoue, H. [Toshiba Corp., Tokyo (Japan)

1998-12-01

The P4140 is a 3 cathode-ray tube (CRT) video data wall projector for super video graphics array (SVGA) signals. It is used as an image display unit, providing a large screen when several sets are put together. A high-quality picture has been realized by higher resolution and improved color uniformity technology. A new convergence adjustment system has also been developed through the optimal combination of digital and analog technologies. This video data wall installation has been greatly enhanced by the automation of cubes and cube performance settings. The P4140 video data wall projector can be used for displaying not only data but video as well. (author)

Surface-confined fluorescence enhancement of Au nanoclusters anchoring to a two-dimensional ultrathin nanosheet toward bioimaging

Science.gov (United States)

Tian, Rui; Yan, Dongpeng; Li, Chunyang; Xu, Simin; Liang, Ruizheng; Guo, Lingyan; Wei, Min; Evans, David G.; Duan, Xue

2016-05-01

Gold nanoclusters (Au NCs) as ultrasmall fluorescent nanomaterials possess discrete electronic energy and unique physicochemical properties, but suffer from relatively low quantum yield (QY) which severely affects their application in displays and imaging. To solve this conundrum and obtain highly-efficient fluorescent emission, 2D exfoliated layered double hydroxide (ELDH) nanosheets were employed to localize Au NCs with a density as high as 5.44 × 1013 cm-2, by virtue of the surface confinement effect of ELDH. Both experimental studies and computational simulations testify that the excited electrons of Au NCs are strongly confined by MgAl-ELDH nanosheets, which results in a largely promoted QY as well as prolonged fluorescence lifetime (both ~7 times enhancement). In addition, the as-fabricated Au NC/ELDH hybrid material exhibits excellent imaging properties with good stability and biocompatibility in the intracellular environment. Therefore, this work provides a facile strategy to achieve highly luminescent Au NCs via surface-confined emission enhancement imposed by ultrathin inorganic nanosheets, which can be potentially used in bio-imaging and cell labelling.Gold nanoclusters (Au NCs) as ultrasmall fluorescent nanomaterials possess discrete electronic energy and unique physicochemical properties, but suffer from relatively low quantum yield (QY) which severely affects their application in displays and imaging. To solve this conundrum and obtain highly-efficient fluorescent emission, 2D exfoliated layered double hydroxide (ELDH) nanosheets were employed to localize Au NCs with a density as high as 5.44 × 1013 cm-2, by virtue of the surface confinement effect of ELDH. Both experimental studies and computational simulations testify that the excited electrons of Au NCs are strongly confined by MgAl-ELDH nanosheets, which results in a largely promoted QY as well as prolonged fluorescence lifetime (both ~7 times enhancement). In addition, the as-fabricated Au NC

Action video game training for cognitive enhancement

OpenAIRE

Green, C. Shawn; Bavelier, Daphné

2015-01-01

Here we review the literature examining the perceptual, attentional, and cognitive benefits of playing one sub-type of video games known as ‘action video games,’ as well as the mechanistic underpinnings of these behavioral effects. We then outline evidence indicating the potential usefulness of these commercial off-the-shelf games for practical, real-world applications such as rehabilitation or the training of job-related skills. Finally, we discuss potential core characteristics of action vi...

Using Fluorescence Intensity of Enhanced Green Fluorescent Protein to Quantify Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Erin Wilson

2018-05-01

Full Text Available A variety of direct and indirect methods have been used to quantify planktonic and biofilm bacterial cells. Direct counting methods to determine the total number of cells include plate counts, microscopic cell counts, Coulter cell counting, flow cytometry, and fluorescence microscopy. However, indirect methods are often used to supplement direct cell counting, as they are often more convenient, less time-consuming, and require less material, while providing a number that can be related to the direct cell count. Herein, an indirect method is presented that uses fluorescence emission intensity as a proxy marker for studying bacterial accumulation. A clinical strain of Pseudomonas aeruginosa was genetically modified to express a green fluorescent protein (PA14/EGFP. The fluorescence intensity of EGFP in live cells was used as an indirect measure of live cell density, and was compared with the traditional cell counting methods of optical density (OD600 and plate counting (colony-forming units (CFUs. While both OD600 and CFUs are well-established methods, the use of fluorescence spectroscopy to quantify bacteria is less common. This study demonstrates that EGFP intensity is a convenient reporter for bacterial quantification. In addition, we demonstrate the potential for fluorescence spectroscopy to be used to measure the quantity of PA14/EGFP biofilms, which have important human health implications due to their antimicrobial resistance. Therefore, fluorescence spectroscopy could serve as an alternative or complementary quick assay to quantify bacteria in planktonic cultures and biofilms.

Reviews in instructional video

NARCIS (Netherlands)

van der Meij, Hans

2017-01-01

This study investigates the effectiveness of a video tutorial for software training whose construction was based on a combination of insights from multimedia learning and Demonstration-Based Training. In the videos, a model of task performance was enhanced with instructional features that were

Smart detection of microRNAs through fluorescence enhancement on a photonic crystal.

Science.gov (United States)

Pasquardini, L; Potrich, C; Vaghi, V; Lunelli, L; Frascella, F; Descrovi, E; Pirri, C F; Pederzolli, C

2016-04-01

The detection of low abundant biomarkers, such as circulating microRNAs, demands innovative detection methods with increased resolution, sensitivity and specificity. Here, a biofunctional surface was implemented for the selective capture of microRNAs, which were detected through fluorescence enhancement directly on a photonic crystal. To set up the optimal biofunctional surface, epoxy-coated commercially available microscope slides were spotted with specific anti-microRNA probes. The optimal concentration of probe as well as of passivating agent were selected and employed for titrating the microRNA hybridization. Cross-hybridization of different microRNAs was also tested, resulting negligible. Once optimized, the protocol was adapted to the photonic crystal surface, where fluorescent synthetic miR-16 was hybridized and imaged with a dedicated equipment. The photonic crystal consists of a dielectric multilayer patterned with a grating structure. In this way, it is possible to take advantage from both a resonant excitation of fluorophores and an angularly redirection of the emitted radiation. As a result, a significant fluorescence enhancement due to the resonant structure is collected from the patterned photonic crystal with respect to the outer non-structured surface. The dedicated read-out system is compact and based on a wide-field imaging detection, with little or no optical alignment issues, which makes this approach particularly interesting for further development such as for example in microarray-type bioassays. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhancement of hand hygiene compliance among health care workers from a hemodialysis unit using video-monitoring feedback.

Science.gov (United States)

Sánchez-Carrillo, Laura Arelí; Rodríguez-López, Juan Manuel; Galarza-Delgado, Dionisio Ángel; Baena-Trejo, Laura; Padilla-Orozco, Magaly; Mendoza-Flores, Lidia; Camacho-Ortiz, Adrián

2016-08-01

The importance of hand hygiene in the prevention of health care-associated infection is well known. Experience with hand hygiene compliance (HHC) evaluation in hemodialysis units is scarce. This study was a 3-phase, prospective longitudinal intervention study during a 5-month period in a 13-bed hemodialysis unit at a university hospital in Northern Mexico. The unit performs an average of 1,150 hemodialysis procedures per month. Compliance was evaluated by a direct observer and a video assisted observer. Feedback was given to health care workers in the form of educational sessions and confidential reports and video analysis of compliance and noncompliance. A total of 5,402 hand hygiene opportunities were registered; 5,201 during 7,820 minutes of video footage and 201 by direct observation during 1,180 minutes. Lower compliance during the baseline evaluation was observed by video monitoring compared with direct observation (P hand hygiene compliance. Video-assisted monitoring of hand hygiene is an excellent method for the evaluation of HHC in a hemodialysis unit; enhanced HHC can be achieved through a feedback program to the hemodialysis staff that includes video examples and confidential reports. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The Use of Individualized Video Modeling to Enhance Positive Peer Interactions in Three Preschool Children

Science.gov (United States)

Green, Vanessa A.; Prior, Tessa; Smart, Emily; Boelema, Tanya; Drysdale, Heather; Harcourt, Susan; Roche, Laura; Waddington, Hannah

2017-01-01

The study described in this article sought to enhance the social interaction skills of 3 preschool children using video modeling. All children had been assessed as having difficulties in their interactions with peers. Two were above average on internalizing problems and the third was above average on externalizing problems. The study used a…

Memory-cenric video processing

NARCIS (Netherlands)

Beric, A.; Meerbergen, van J.; Haan, de G.; Sethuraman, R.

2008-01-01

This work presents a domain-specific memory subsystem based on a two-level memory hierarchy. It targets the application domain of video post-processing applications including video enhancement and format conversion. These applications are based on motion compensation and/or broad class of content

Fluorescence spectroscopy of gastrointestinal tumors using δ-ALA

Science.gov (United States)

Borisova, E. G.; Vladimirov, B. G.; Angelov, I. G.; Avramov, L. A.

2007-03-01

In the recent study delta-aminolevulinic acid/Protoporphyrin IX (δ-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus and stomach. The δ-ALA is administered per os six hours before measurements at dose 20mg/kg weight. High-power light-emitting diode at 405 nm is used as an excitation source. Special opto-mechanical device is built to use the light guide of standard video-endoscopic system (Olimpus Corp.). Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer (USB4000, OceanOptics Inc.). The fluorescence detected from tumor sites has very complex spectral origins. It consists of autofluorescence, fluorescence from exogenous fluorophores and re-absorption from the chromophores accumulated in the tissue investigated. Mucosa autofluorescence lies at 450-600 nm region. The fluorescence of PpIX is clearly pronounced at the 630-710 nm region. Deep minima in the tumor fluorescence signals are observed in the region 540-575 nm, related to hemoglobin re-absorption. Such high hemoglobin content is an indication of the tumors neovascularisation and it is clearly pronounced in all dysplastic and tumor sites investigated. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of δ-ALA/PpIX only in abnormal sites and gives high contrast when lesion borders are determined from clinicians during video observation in the process of diagnostic procedure. Very good correlation between fluorescence signals and histology examination results of the lesions investigated is achieved.

OPTIMISATION OF BUFFER SIZE FOR ENHANCING QOS OF VIDEO TRAFFIC USING CROSS LAYERED HYBRID TRANSPORT LAYER PROTOCOL APPROACH

Directory of Open Access Journals (Sweden)

S. Matilda

2011-03-01

Full Text Available Video streaming is gaining importance, with the wide popularity of multimedia rich applications in the Internet. Video streams are delay sensitive and require seamless flow for continuous visualization. Properly designed buffers offer a solution to queuing delay. The diagonally opposite QoS metrics associated with video traffic poses an optimization problem, in the design of buffers. This paper is a continuation of our previous work [1] and deals with the design of buffers. It aims at finding the optimum buffer size for enhancing QoS offered to video traffic. Network-centric QoS provisioning approach, along with hybrid transport layer protocol approach is adopted, to arrive at an optimum size which is independent of RTT. In this combinational approach, buffers of routers and end devices are designed to satisfy the various QoS parameters at the transport layer. OPNET Modeler is used to simulate environments for testing the design. Based on the results of simulation it is evident that the hybrid transport layer protocol approach is best suited for transmitting video traffic as it supports the economical design.

Optimization of video capturing and tone mapping in video camera systems

NARCIS (Netherlands)

Cvetkovic, S.D.

2011-01-01

Image enhancement techniques are widely employed in many areas of professional and consumer imaging, machine vision and computational imaging. Image enhancement techniques used in surveillance video cameras are complex systems involving controllable lenses, sensors and advanced signal processing. In

Hot spots based gold nanostar@SiO2@CdSe/ZnS quantum dots complex with strong fluorescence enhancement

Directory of Open Access Journals (Sweden)

Feng Shan

2018-02-01

Full Text Available In this paper, a novel gold nanostar (NS@SiO2@CdSe/ZnS quantum dots (QDs complex with plasmon-enhanced fluorescence synthesized using a step-by-step surface linkage method was presented. The gold NS was synthesized by the seed growth method. The synthesized gold NS with the apexes structure has a hot-spot effect due to the strong electric field distributed at its sharp apexes, which leads to a plasmon resonance enhancement. Because the distance between QDs and metal nanostructures can be precisely controlled by this method, the relationship between enhancement and distance was revealed. The thickness of SiO2 shell was also optimized and the optimum distance of about 21 nm was obtained. The highest fluorescence enhancement of 4.8-fold accompanied by a minimum fluorescence lifetime of 2.3 ns were achieved. This strong enhancement comes from the hot spots distributed at the sharp tip of our constructed nanostructure. Through the finite element method, we calculated the field distribution on the surface of NS and found that gold NS with the sharpest apexes exhibited the highest field enhancement, which matches well with our experiment result. This complex shows tremendous potential applications for liquid-dependent biometric imaging systems.

Hot spots based gold nanostar@SiO2@CdSe/ZnS quantum dots complex with strong fluorescence enhancement

Science.gov (United States)

Shan, Feng; Su, Dan; Li, Wei; Hu, Wei; Zhang, Tong

2018-02-01

In this paper, a novel gold nanostar (NS)@SiO2@CdSe/ZnS quantum dots (QDs) complex with plasmon-enhanced fluorescence synthesized using a step-by-step surface linkage method was presented. The gold NS was synthesized by the seed growth method. The synthesized gold NS with the apexes structure has a hot-spot effect due to the strong electric field distributed at its sharp apexes, which leads to a plasmon resonance enhancement. Because the distance between QDs and metal nanostructures can be precisely controlled by this method, the relationship between enhancement and distance was revealed. The thickness of SiO2 shell was also optimized and the optimum distance of about 21 nm was obtained. The highest fluorescence enhancement of 4.8-fold accompanied by a minimum fluorescence lifetime of 2.3 ns were achieved. This strong enhancement comes from the hot spots distributed at the sharp tip of our constructed nanostructure. Through the finite element method, we calculated the field distribution on the surface of NS and found that gold NS with the sharpest apexes exhibited the highest field enhancement, which matches well with our experiment result. This complex shows tremendous potential applications for liquid-dependent biometric imaging systems.

An improved pyrolysis route to synthesize carbon-coated CdS quantum dots with fluorescence enhancement effect

International Nuclear Information System (INIS)

Zhang Kejie; Liu Xiaoheng

2011-01-01

Well-dispersed carbon-coated CdS (CdS-C) quantum dots were successfully prepared via the improved pyrolysis of bis(1-dodecanethiol)-cadmium(II) under nitrogen atmosphere. This simple method effectively solved the sintered problem resulted from conventional pyrolysis process. The experimental results indicated that most of the as-prepared nanoparticles displayed well-defined core-shell structures. The CdS cores with diameter of ∼5 nm exhibited hexagonal crystal phase, the carbon shells with thickness of ∼2 nm acted as a good dispersion medium to prevent CdS particles from aggregation, and together with CdS effectively formed a monodisperse CdS-Carbon nanocomposite. This composite presented a remarkable fluorescence enhancement effect, which indicated that the prepared nanoparticles might be a promising photoresponsive material or biosensor. This improved pyrolysis method might also offer a facile way to prepare other carbon-coated semiconductor nanostructures. - Graphical abstract: We demonstrated a facile approach to synthesize well-dispersed carbon-coated CdS quantum dots. The as-prepared nanoparticles presented remarkable fluorescence enhancement effect. Highlights: → Carbon-coated CdS quantum dots were synthesized by an one-step pyrolysis method. → Well-dispersed CdS-carbon nanoparticles were obtained by an acid treatment process. → As-prepared nanoparticles presented remarkable fluorescence enhancement effect.

A System to Generate SignWriting for Video Tracks Enhancing Accessibility of Deaf People

Directory of Open Access Journals (Sweden)

Elena Verdú

2017-12-01

Full Text Available Video content has increased much on the Internet during last years. In spite of the efforts of different organizations and governments to increase the accessibility of websites, most multimedia content on the Internet is not accessible. This paper describes a system that contributes to make multimedia content more accessible on the Web, by automatically translating subtitles in oral language to SignWriting, a way of writing Sign Language. This system extends the functionality of a general web platform that can provide accessible web content for different needs. This platform has a core component that automatically converts any web page to a web page compliant with level AA of WAI guidelines. Around this core component, different adapters complete the conversion according to the needs of specific users. One adapter is the Deaf People Accessibility Adapter, which provides accessible web content for the Deaf, based on SignWritting. Functionality of this adapter has been extended with the video subtitle translator system. A first prototype of this system has been tested through different methods including usability and accessibility tests and results show that this tool can enhance the accessibility of video content available on the Web for Deaf people.

Biocompatible fluorescence-enhanced ZrO2-CdTe quantum dot nanocomposite for in vitro cell imaging

Science.gov (United States)

Lu, Zhisong; Zhu, Zhihong; Zheng, Xinting; Qiao, Yan; Guo, Jun; Li, Chang Ming

2011-04-01

With advances of quantum dots (QDs) in bioimaging applications, various materials have been used to coat QDs to reduce their nanotoxicity; however, the coating could introduce new toxic sources and quench the fluorescence in bioimaging applications. In this work, ZrO2, an excellent ceramic material with low extinction coefficient and good biocompatibility, is utilized to coat CdTe QDs for the first time. Experimental results show that ZrO2-QD nanocomposites with the size of ~ 30 nm possess enhanced fluorescence emission, lower nanotoxicity and gradually increased fluorescence under 350 nm light illumination. After functionalization with folic acid, they were applied to label cultured HeLa cells effectively. Therefore, the ZrO2-QD nanocomposites could be promising biocompatible nanomaterials with strong fluorescence emission to replace or complement QDs in biomedical applications.

Biocompatible fluorescence-enhanced ZrO2-CdTe quantum dot nanocomposite for in vitro cell imaging

International Nuclear Information System (INIS)

Lu Zhisong; Zhu Zhihong; Zheng Xinting; Qiao Yan; Li Changming; Guo Jun

2011-01-01

With advances of quantum dots (QDs) in bioimaging applications, various materials have been used to coat QDs to reduce their nanotoxicity; however, the coating could introduce new toxic sources and quench the fluorescence in bioimaging applications. In this work, ZrO 2 , an excellent ceramic material with low extinction coefficient and good biocompatibility, is utilized to coat CdTe QDs for the first time. Experimental results show that ZrO 2 -QD nanocomposites with the size of ∼ 30 nm possess enhanced fluorescence emission, lower nanotoxicity and gradually increased fluorescence under 350 nm light illumination. After functionalization with folic acid, they were applied to label cultured HeLa cells effectively. Therefore, the ZrO 2 -QD nanocomposites could be promising biocompatible nanomaterials with strong fluorescence emission to replace or complement QDs in biomedical applications.

Examination of mechanisms underlying enhanced memory performance in action video game players: a pilot study.

Science.gov (United States)

Li, Xianchun; Cheng, Xiaojun; Li, Jiaying; Pan, Yafeng; Hu, Yi; Ku, Yixuan

2015-01-01

Previous studies have shown enhanced memory performance resulting from extensive action video game playing. The mechanisms underlying the cognitive benefit were investigated in the current study. We presented two types of retro-cues, with variable intervals to memory array (Task 1) or test array (Task 2), during the retention interval in a change detection task. In Task 1, action video game players demonstrated steady performance while non-action video game players showed decreased performance as cues occurred later, indicating their performance difference increased as the cue-to-memory-array intervals became longer. In Task 2, both participant groups increased their performance at similar rates as cues presented later, implying the performance difference in two groups were irrespective of the test-array-to-cue intervals. These findings suggested that memory benefit from game plays is not attributable to the higher ability of overcoming interference from the test array, but to the interactions between the two processes of protection from decay and resistance from interference, or from alternative hypotheses. Implications for future studies were discussed.

Investigating Students' Use and Adoption of "With-Video Assignments": Lessons Learnt for Video-Based Open Educational Resources

Science.gov (United States)

Pappas, Ilias O.; Giannakos, Michail N.; Mikalef, Patrick

2017-01-01

The use of video-based open educational resources is widespread, and includes multiple approaches to implementation. In this paper, the term "with-video assignments" is introduced to portray video learning resources enhanced with assignments. The goal of this study is to examine the factors that influence students' intention to adopt…

Use of Active-Play Video Games to Enhance Aerobic Fitness in Schizophrenia: Feasibility, Safety, and Adherence.

Science.gov (United States)

Kimhy, David; Khan, Samira; Ayanrouh, Lindsey; Chang, Rachel W; Hansen, Marie C; Lister, Amanda; Ballon, Jacob S; Vakhrusheva, Julia; Armstrong, Hilary F; Bartels, Matthew N; Sloan, Richard P

2016-02-01

Active-play video games have been used to enhance aerobic fitness in various clinical populations, but their use among individuals with schizophrenia has been limited. Feasibility, acceptability, safety, and adherence data were obtained for use of aerobic exercise (AE) equipment by 16 individuals with schizophrenia during a 12-week AE program consisting of three one-hour exercise sessions per week. Equipment included exercise video games for Xbox 360 with Kinect motion sensing devices and traditional exercise equipment. Most participants (81%) completed the training, attending an average of 79% of sessions. The proportion of time spent playing Xbox (39%) exceeded time spent on any other type of equipment. When using Xbox, participants played 2.24±1.59 games per session and reported high acceptability and enjoyment ratings, with no adverse events. Measures of feasibility, acceptability, adherence, and safety support the integration of active-play video games into AE training for people with schizophrenia.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm3+-Yb3+ doped optical fiber beyond plasmonics

International Nuclear Information System (INIS)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K.

2015-01-01

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb 3+ ) and Thulium (Tm 3+ ) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb 3+ . Four times enhancement of Yb 3+ emission of 900–1100 nm and Tm 3+ upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs

Fluorescence-enhanced optical imaging in large tissue volumes using a gain-modulated ICCD camera

International Nuclear Information System (INIS)

Godavarty, Anuradha; Eppstein, Margaret J; Zhang, Chaoyang; Theru, Sangeeta; Thompson, Alan B; Gurfinkel, Michael; Sevick-Muraca, Eva M

2003-01-01

A novel image-intensified charge-coupled device (ICCD) imaging system has been developed to perform 3D fluorescence tomographic imaging in the frequency-domain using near-infrared contrast agents. The imager is unique since it (i) employs a large tissue-mimicking phantom, which is shaped and sized to resemble a female breast and part of the extended chest-wall region, and (ii) enables rapid data acquisition in the frequency-domain by using a gain-modulated ICCD camera. Diffusion model predictions are compared to experimental measurements using two different referencing schemes under two different experimental conditions of perfect and imperfect uptake of fluorescent agent into a target. From these experimental measurements, three-dimensional images of fluorescent absorption were reconstructed using a computationally efficient variant of the approximate extended Kalman filter algorithm. The current work represents the first time that 3D fluorescence-enhanced optical tomographic reconstructions have been achieved from experimental measurements of the time-dependent light propagation on a clinically relevant breast-shaped tissue phantom using a gain-modulated ICCD camera

Comparative study of protoporphyrin IX fluorescence image enhancement methods to improve an optical imaging system for oral cancer detection

Science.gov (United States)

Jiang, Ching-Fen; Wang, Chih-Yu; Chiang, Chun-Ping

2011-07-01

Optoelectronics techniques to induce protoporphyrin IX fluorescence with topically applied 5-aminolevulinic acid on the oral mucosa have been developed to noninvasively detect oral cancer. Fluorescence imaging enables wide-area screening for oral premalignancy, but the lack of an adequate fluorescence enhancement method restricts the clinical imaging application of these techniques. This study aimed to develop a reliable fluorescence enhancement method to improve PpIX fluorescence imaging systems for oral cancer detection. Three contrast features, red-green-blue reflectance difference, R/B ratio, and R/G ratio, were developed first based on the optical properties of the fluorescence images. A comparative study was then carried out with one negative control and four biopsy confirmed clinical cases to validate the optimal image processing method for the detection of the distribution of malignancy. The results showed the superiority of the R/G ratio in terms of yielding a better contrast between normal and neoplastic tissue, and this method was less prone to errors in detection. Quantitative comparison with the clinical diagnoses in the four neoplastic cases showed that the regions of premalignancy obtained using the proposed method accorded with the expert's determination, suggesting the potential clinical application of this method for the detection of oral cancer.

Spectrofluorimetric determination of gemifloxacin mesylate and linezolid in pharmaceutical formulations: Application of quinone-based fluorophores and enhanced native fluorescence

Directory of Open Access Journals (Sweden)

Moussa Bahia Abbas

2014-03-01

Full Text Available Quinone-based fluorophores and enhanced native fluorescence techniques were applied for a fast quantitative analysis of gemifloxacin mesylate (GEM and linezolid (LIN in pharmaceutical formulations. For this purpose, three sensitive, accurate and precise spectrofluorimetric methods were developed. GEM, as an n-electron donor, reacts with 7,7,8,8-tetracyanoquinodimethane (method A and 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (method B as п-electron acceptors, forming charge transfer complexes that exhibit high fluorescence intensity at 441 and 390 nm upon excitation at 260 and 339 nm, respectively. Method C depends on measurement of enhanced native fluorescence of LIN in phosphate buffer (pH 5 at 380 nm upon excitation at 260 nm. Experimental factors affecting fluorescence intensity were optimized. Linearity was obtained over concentration ranges 50-500, 10-60 and 20-400 ng mL-1 for methods A, B and C, respectively. The developed methods were validated and successfully applied for determination of the cited drugs in tablets.

Enhanced fluorescence of tetrasulfonated zinc phthalocyanine by graphene quantum dots and its application in molecular sensing/imaging.

Science.gov (United States)

Wang, Jian; Zhang, Yanjun; Ye, Jiqing; Jiang, Zhou

2017-06-01

When excited at 435 nm, tetra-sulfonate zinc phthalocyanine (ZnPcS 4 ) emitted dual fluorescence at 495 and 702 nm. The abnormal fluorescence at 495 nm was experimentally studied and analyzed in detail for the first time. The abnormal fluorescence at 495 nm was deduced to originate from triplet-triplet (T-T) energy transfer of excited phthalocyanine ( 3 *ZnPcS 4 ). Furthermore, graphene quantum dots (GQDs) enhanced the 495 nm fluorescence quantum yield (Q) of ZnPcS 4 . The fluorescence properties of ZnPcS 4 -GQDs conjugate were retained in a cellular environment. Based on the fluorescence of ZnPcS 4 -GQDs conjugate, we designed and prepared an Apt29/thrombin/Apt15 sandwich thrombin sensor with high specificity and affinity. This cost-saving, simple operational sensing strategy can be extended to use in sensing/imaging of other biomolecules. Copyright © 2016 John Wiley & Sons, Ltd.

Talking Video in 'Everyday Life'

DEFF Research Database (Denmark)

McIlvenny, Paul

For better or worse, video technologies have made their way into many domains of social life, for example in the domain of therapeutics. Techniques such as Marte Meo, Video Interaction Guidance (ViG), Video-Enhanced Reflection on Communication, Video Home Training and Video intervention....../prevention (VIP) all promote the use of video as a therapeutic tool. This paper focuses on media therapeutics and the various in situ uses of video technologies in the mass media for therapeutic purposes. Reality TV parenting programmes such as Supernanny, Little Angels, The House of Tiny Tearaways, Honey, We...... observation and instruction (directives) relayed across different spaces; 2) the use of recorded video by participants to visualise, spatialise and localise talk and action that is distant in time and/or space; 3) the translating, stretching and cutting of social experience in and through the situated use...

Differential tissue expression of enhanced green fluorescent protein in 'green mice'.

Science.gov (United States)

Ma, De-Fu; Tezuka, Hideo; Kondo, Tetsuo; Sudo, Katsuko; Niu, Dong-Feng; Nakazawa, Tadao; Kawasaki, Tomonori; Yamane, Tetsu; Nakamura, Nobuki; Katoh, Ryohei

2010-06-01

In order to clarify tissue expression of enhanced green fluorescent protein (EGFP) in 'green mice' from a transgenic line having an EGFP cDNA under the control of a chicken beta-actin promoter and cytomegalovirus enhancer, we studied the expression of EGFP in various organs and tissues from these 'green mice' by immunohistochemistry with anti- EGFP antibody in conjunction with direct observation for EGFP fluorescence using confocal laser scanning microscopy. On immunohistochemical examination and on direct observation by confocal laser scanning microscopy, the level of EGFP expression varied among organs and tissues. EGFP expression was diffusely and strongly observed in the skin, pituitary, thyroid gland, parathyroid gland, heart, gall bladder, pancreas, adrenals and urinary bladder. There was only sporadic and weak expression of EGFP in the epithelium of the trachea, bronchus of the lung, stratified squamous epithelium and gastric glands of the stomach, hepatic bile ducts of the liver, glomeruli and renal tubules of the kidney and endo-metrial glands of the uterus. Furthermore, EGFP was only demonstrated within the goblet and paneth cells in the colon and small intestine, the tall columnar cells in the ductus epididymis, and the leydig cells in the testis. In conclusion, our results show that EGFP is differentially expressed in organs and tissues of 'green mice', which indicates that 'green mice' may prove useful for research involving transplantation and tissue clonality.

Enhancements to the Sentinel Fireball Network Video Software

Science.gov (United States)

Watson, Wayne

2009-05-01

The Sentinel Fireball Network that supports meteor imaging of bright meteors (fireballs) has been in existence for over ten years. Nearly five years ago it moved from gathering meteor data with a camera and VCR video tape to a fisheye lens attached to a hardware device, the Sentinel box, which allowed meteor data to be recorded on a PC operating under real-time Linux. In 2006, that software, sentuser, was made available on Apple, Linux, and Window operating systems using the Python computer language. It provides basic video and management functionality and a small amount of analytic software capability. This paper describes the new and attractive future features of the software, and, additionally, it reviews some of the research and networks from the past and present using video equipment to collect and analyze fireball data that have applicability to sentuser.

Highly thermostable fluorescent proteins

Science.gov (United States)

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

2011-03-22

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

Getting Serious About Games -- Using Video Game-Based Learning to Enhance Nuclear Terrorism Preparedness

Science.gov (United States)

2012-03-01

grant, HH&S provides writers and producers with accurate and timely health content for the scripts that not only enhances the drama , but also educates...the fact that today’s generation came of age in a technology rich environment that changed the way they accept and process information. Consequently...to kill: A call to action against TV, movie and video game violence. New York: Crown Archetype. Hampton, B., Altmire, B., Brunjes, B., Jennings, D. M

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

Using Interactive Video Instruction To Enhance Public Speaking Instruction.

Science.gov (United States)

Cronin, Michael W.; Kennan, William R.

Noting that interactive video instruction (IVI) should not and cannot replace classroom instruction, this paper offers an introduction to interactive video instruction as an innovative technology that can be used to expand pedagogical opportunities in public speaking instruction. The paper: (1) defines the distinctive features of IVI; (2) assesses…

Fluorescence enhancement of DNA-silver nanoclusters from guanine proximity

Energy Technology Data Exchange (ETDEWEB)

Yeh, Hsin-chih [Los Alamos National Laboratory; Sharma, Jaswinder [Los Alamos National Laboratory; Yoo, Hyojong [Los Alamos National Laboratory; Martinez, Jennifer S [Los Alamos National Laboratory

2010-01-01

Oligonucleotide-templated, silver nanoclusters (DNA/Ag NCs) are a versatile set of fluorophores and have already been used for live cell imaging, detection of specific metal ions, and single-nucleotide variation identification. Compared to commonly used organic dyes, these fluorescent nanoclusters have much better photostability and are often a few times brighter. Owing to their small size, simple preparation, and biocompatibility (i.e. made of nontoxic metals), DNA/Ag NCs should find more applications in biological imaging and chemical detection in the years to come. While clearly promising as new fluorophores, DNA/Ag NCs possess a unique and poorly understood dynamic process not shared by organic dyes or photoluminescent nanocrystals - the conversion among different NC species due to silver oxidation/reduction or NC regrouping. While this environmental sensitivity can be viewed as a drawback, in the appropriate context, it can be used as a sensor or reporter. Often reversible, conversions among different NC species have been found to depend upon a number of factors, including time, temperature, oxygen and salt content. In this communication, we report significant fluorescence enhancement of DNA/Ag NCs via interactions with guanine-rich DNA sequences. Moreover, we demonstrated this property can be used for sensitive detection of specific target DNA from a human oncogene (i.e. Braf gene).

Double-labeled donor probe can enhance the signal of fluorescence resonance energy transfer (FRET) in detection of nucleic acid hybridization

Science.gov (United States)

Okamura, Yukio; Kondo, Satoshi; Sase, Ichiro; Suga, Takayuki; Mise, Kazuyuki; Furusawa, Iwao; Kawakami, Shigeki; Watanabe, Yuichiro

2000-01-01

A set of fluorescently-labeled DNA probes that hybridize with the target RNA and produce fluorescence resonance energy transfer (FRET) signals can be utilized for the detection of specific RNA. We have developed probe sets to detect and discriminate single-strand RNA molecules of plant viral genome, and sought a method to improve the FRET signals to handle in vivo applications. Consequently, we found that a double-labeled donor probe labeled with Bodipy dye yielded a remarkable increase in fluorescence intensity compared to a single-labeled donor probe used in an ordinary FRET. This double-labeled donor system can be easily applied to improve various FRET probes since the dependence upon sequence and label position in enhancement is not as strict. Furthermore this method could be applied to other nucleic acid substances, such as oligo RNA and phosphorothioate oligonucleotides (S-oligos) to enhance FRET signal. Although the double-labeled donor probes labeled with a variety of fluorophores had unexpected properties (strange UV-visible absorption spectra, decrease of intensity and decay of donor fluorescence) compared with single-labeled ones, they had no relation to FRET enhancement. This signal amplification mechanism cannot be explained simply based on our current results and knowledge of FRET. Yet it is possible to utilize this double-labeled donor system in various applications of FRET as a simple signal-enhancement method. PMID:11121494

Streaming Video to Enhance Students' Reflection in Dance Education

Science.gov (United States)

Leijen, Ali; Lam, Ineke; Wildschut, Liesbeth; Simons, P. Robert-Jan; Admiraal, Wilfried

2009-01-01

This paper presents an evaluation case study that describes the experiences of 15 students and 2 teachers using a video-based learning environment, DiViDU, to facilitate students' daily reflection activities in a composition course and a ballet course. To support dance students' reflection processes streaming video was applied as follows: video…

Spatially Controlled Fabrication of Brightly Fluorescent Nanodiamond-Array with Enhanced Far-Red Si-V Luminescence

Science.gov (United States)

Singh, Sonal; Thomas, Vinoy; Martyshkin, Dmitry; Kozlovskaya, Veronika; Kharlampieva, Eugenia

2014-01-01

We demonstrate a novel approach to precise pattern fluorescent nanodiamond-arrays with enhanced far-red intense photostable luminescence from silicon-vacancy (Si-V) defect centers. The precision-patterned pre-growth seeding of nanodiamonds is achieved by scanning probe “Dip-Pen” nanolithography technique using electrostatically-driven transfer of nanodiamonds from “inked” cantilevers to a UV-treated hydrophilic SiO2 substrate. The enhanced emission from nanodiamond-dots in the far-red is achieved by incorporating Si-V defect centers in subsequent chemical vapor deposition treatment. The development of a suitable nanodiamond ink, mechanism of ink transport, and effect of humidity, dwell time on nanodiamond patterning are investigated. The precision-patterning of as-printed (pre-CVD) arrays with dot diameter and dot height as small as 735 nm ± 27 nm, 61 nm ± 3 nm, respectively and CVD-treated fluorescent ND-arrays with consistently patterned dots having diameter and height as small as 820 nm ± 20 nm, 245 nm ± 23 nm, respectively using 1 s dwell time and 30% RH is successfully achieved. We anticipate that the far-red intense photostable luminescence (~738 nm) observed from Si-V defect centers integrated in spatially arranged nanodiamonds could be beneficial for the development of the next generation fluorescent based devices and applications. PMID:24394286

Enhancement of allergic skin wheal responses in patients with atopic eczema/dermatitis syndrome by playing video games or by a frequently ringing mobile phone.

Science.gov (United States)

Kimata, H

2003-06-01

Playing video games causes physical and psychological stress, including increased heart rate and blood pressure and aggression-related feelings. Use of mobile phones is very popular in Japan, and frequent ringing is a common and intrusive part of Japanese life. Atopic eczema/dermatitis syndrome is often exacerbated by stress. Stress increases serum IgE levels, skews cytokine pattern towards Th2 type, enhances allergen-induced skin wheal responses, and triggers mast cell degranulation via substance P, vasoactive intestinal peptide and nerve growth factor. (1). In the video game study, normal subjects (n = 25), patients with allergic rhinitis (n = 25) or atopic eczema/dermatitis syndrome (n = 25) played a video game (STREET FIGHTER II) for 2 h. Before and after the study, allergen-induced wheal responses, plasma levels of substance P, vasoactive intestinal peptide and nerve growth factor, and in vitro production of total IgE, antihouse dust mite IgE and cytokines were measured. (2). In the mobile phone study, normal subjects (n = 27), patients with allergic rhinitis (n = 27) or atopic eczema/dermatitis syndrome (n = 27) were exposed to 30 incidences of ringing mobile phones during 30 min. Before and after the study, allergen-induced wheal responses, plasma levels of substance P, vasoactive intestinal peptide and nerve growth factor were measured. Playing video games had no effect on the normal subjects or the patients with allergic rhinitis. In contrast, playing video games significantly enhanced allergen-induced skin wheal responses and increased plasma levels of substance P, vasoactive intestinal peptide and nerve growth factors in the patients with atopic eczema/dermatitis syndrome. Moreover, playing video games enhanced in vitro production of total IgE and anti-house dust mite IgE with concomitant increased production of IL-4, IL-10 and IL-13 and decreased production of IFN-gamma and IL-12 in the patients with atopic eczema/dermatitis syndrome. However, exposure

Dynamic characterization of hydrophobic and hydrophilic solutes in oleic-acid enhanced transdermal delivery using two-photon fluorescence microscopy

Energy Technology Data Exchange (ETDEWEB)

Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Tsung-Hua [Department of Dermatology, Far Eastern Memorial Hospital, New Taipei City, Taiwan (China); Dong, Chen-Yuan, E-mail: cydong@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Center for Optoelectronic Biomedicine, National Taiwan University, Taipei, Taiwan (China)

2014-10-20

In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.

Using Online Interactive Physics-based Video Analysis Exercises to Enhance Learning

Directory of Open Access Journals (Sweden)

Priscilla W. Laws

2017-04-01

Full Text Available As part of our new digital video age, physics students throughout the world can use smart phones, video cameras, computers and tablets to produce and analyze videos of physical phenomena using analysis software such as Logger Pro, Tracker or Coach. For several years, LivePhoto Physics Group members have created short videos of physical phenomena. They have also developed curricular materials that enable students to make predictions and use video analysis software to verify them. In this paper a new LivePhoto Physics project that involves the creation and testing of a series of Interactive Video Vignettes (IVVs will be described. IVVs are short webbased assignments that take less than ten minutes to complete. Each vignette is designed to present a video of a phenomenon, ask for a student’s prediction about it, and then conduct on-line video observations or analyses that allow the user to compare findings with his or her initial prediction. The Vignettes are designed for web delivery as ungraded exercises to supplement textbook reading, or to serve as pre-lecture or pre-laboratory activities that span a number of topics normally introduced in introductory physics courses. A sample Vignette on the topic of Newton’s Third Law will be described, and the outcomes of preliminary research on the impact of Vignettes on student motivation, learning and attitudes will be summarized.

Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

KAUST Repository

Aly, Shawkat Mohammede; Eita, Mohamed Samir; Khan, Jafar Iqbal; Alarousu, Erkki; Mohammed, Omar F.

2014-01-01

the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic

Part Two: Learning Science Through Digital Video: Student Views on Watching and Creating Videos

Science.gov (United States)

Wade, P.; Courtney, A. R.

2014-12-01

The use of digital video for science education has become common with the wide availability of video imagery. This study continues research into aspects of using digital video as a primary teaching tool to enhance student learning in undergraduate science courses. Two survey instruments were administered to undergraduate non-science majors. Survey One focused on: a) What science is being learned from watching science videos such as a "YouTube" clip of a volcanic eruption or an informational video on geologic time and b) What are student preferences with regard to their learning (e.g. using video versus traditional modes of delivery)? Survey Two addressed students' perspectives on the storytelling aspect of the video with respect to: a) sustaining interest, b) providing science information, c) style of video and d) quality of the video. Undergraduate non-science majors were the primary focus group in this study. Students were asked to view video segments and respond to a survey focused on what they learned from the segments. The storytelling aspect of each video was also addressed by students. Students watched 15-20 shorter (3-15 minute science videos) created within the last four years. Initial results of this research support that shorter video segments were preferred and the storytelling quality of each video related to student learning.

Cyclin B1 Destruction Box-Mediated Protein Instability: The Enhanced Sensitivity of Fluorescent-Protein-Based Reporter Gene System

Directory of Open Access Journals (Sweden)

Chao-Hsun Yang

2013-01-01

Full Text Available The periodic expression and destruction of several cyclins are the most important steps for the exact regulation of cell cycle. Cyclins are degraded by the ubiquitin-proteasome system during cell cycle. Besides, a short sequence near the N-terminal of cyclin B called the destruction box (D-box; CDB is also required. Fluorescent-protein-based reporter gene system is insensitive to analysis because of the overly stable fluorescent proteins. Therefore, in this study, we use human CDB fused with both enhanced green fluorescent protein (EGFP at C-terminus and red fluorescent protein (RFP, DsRed at N-terminus in the transfected human melanoma cells to examine the effects of CDB on different fluorescent proteins. Our results indicated that CDB-fused fluorescent protein can be used to examine the slight gene regulations in the reporter gene system and have the potential to be the system for screening of functional compounds in the future.

Curcumin-Based "Enhanced SNAr" Promoted Ultrafast Fluorescent Probe for Thiophenols Detection in Aqueous Solution and in Living Cells.

Science.gov (United States)

Yue, Yongkang; Huo, Fangjun; Zhang, Yongbin; Chao, Jianbin; Martínez-Máñez, Ramón; Yin, Caixia

2016-11-01

We report herein a highly selective and sensitive turn-on fluorescent probe (compound 1) with a fast response time (less than 2 min) for thiophenol detection based on an "enhanced S N Ar" reaction between thiophenols and a sulfonyl-ester moiety covalently attach to curcumin. Reaction of 1 in Hepes-MeOH (1:1, v/v, pH 7.4) in the presence of 4-methylthiophenol (MTP) resulted in a remarkable enhancement of the fluorescence. A linear response in the presence of MTP of the relative fluorescent intensity (F - F 0 ) of 1 at 536 nm in the 0-40 μM MTP concentration range was found. A limit of detection (LOD) for the detection of MTP of 26 nM, based on the definition by IUPAC (C DL = 3 Sb/m), was calculated. Probe 1 was applied to monitor and imaging exogenous MTP in live cells and to the detection of MTP in real water samples.

Automatic tracking of cells for video microscopy in patch clamp experiments.

Science.gov (United States)

Peixoto, Helton M; Munguba, Hermany; Cruz, Rossana M S; Guerreiro, Ana M G; Leao, Richardson N

2014-06-20

Visualisation of neurons labeled with fluorescent proteins or compounds generally require exposure to intense light for a relatively long period of time, often leading to bleaching of the fluorescent probe and photodamage of the tissue. Here we created a technique to drastically shorten light exposure and improve the targeting of fluorescent labeled cells that is specially useful for patch-clamp recordings. We applied image tracking and mask overlay to reduce the time of fluorescence exposure and minimise mistakes when identifying neurons. Neurons are first identified according to visual criteria (e.g. fluorescence protein expression, shape, viability etc.) and a transmission microscopy image Differential Interference Contrast (DIC) or Dodt contrast containing the cell used as a reference for the tracking algorithm. A fluorescence image can also be acquired later to be used as a mask (that can be overlaid on the target during live transmission video). As patch-clamp experiments require translating the microscope stage, we used pattern matching to track reference neurons in order to move the fluorescence mask to match the new position of the objective in relation to the sample. For the image processing we used the Open Source Computer Vision (OpenCV) library, including the Speeded-Up Robust Features (SURF) for tracking cells. The dataset of images (n = 720) was analyzed under normal conditions of acquisition and with influence of noise (defocusing and brightness). We validated the method in dissociated neuronal cultures and fresh brain slices expressing Enhanced Yellow Fluorescent Protein (eYFP) or Tandem Dimer Tomato (tdTomato) proteins, which considerably decreased the exposure to fluorescence excitation, thereby minimising photodamage. We also show that the neuron tracking can be used in differential interference contrast or Dodt contrast microscopy. The techniques of digital image processing used in this work are an important addition to the set of microscopy

Metal-enhanced fluorescence of mixed coumarin dyes by silver and gold nanoparticles: Towards plasmonic thin-film luminescent solar concentrator

Energy Technology Data Exchange (ETDEWEB)

El-Bashir, S.M., E-mail: elbashireg@yahoo.com [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia); Department of Physics Faculty of Science, Benha University (Egypt); Barakat, F.M.; AlSalhi, M.S. [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia)

2013-11-15

Poly(methyl methacrylate) (PMMA) nanocomposite films doped with mixed coumarin dyestuffs and noble metal nanoparticles (60 nm silver and 100 nm gold) were prepared by spin coating technique. The effect of silver and gold nanoparticles on the film properties was studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis absorption and fluorescence spectroscopy measurements. DSC measurements indicated the increase of the glass transition temperature of the films by increasing nanogold concentration, recommending their promising thermal stability towards hot climates. It was found that the fluorescence signals of the mixed coumarin dyes were amplified by 5.4 and 7.15 folds as a result of metal enhanced fluorescence (MEF). The research outcomes offered a potential application of these films in solar energy conversion by plasmonic thin film luminescent solar concentrator (PTLSC). -- Graphical abstract: Plasmonic thin film luminescent solar concentrators. Highlights: • Metal enhanced fluorescence was achieved for mixed coumarin dyes doped in PMMA nanocomposite films. • The amplification of the fluorescence signals is dependent on the concentration of silver and gold nanoparticles. • These films is considered as potential candidates for plasmonic thin film luminescent solar concentrators (PTLSCs)

Fabrication of Au{sub nanoparticle}@mSiO{sub 2}@Y{sub 2}O{sub 3}:Eu nanocomposites with enhanced fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, Huiqin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an, 710069 (China); College of Chemistry & Chemical Engineering, Baoji University of Arts & Sciences, Baoji, 721013 (China); Kang, Jianmiao [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an, 710069 (China); Yang, Jianhui, E-mail: jianhui@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an, 710069 (China); Wu, Biao, E-mail: wubiao@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an, 710069 (China)

2016-07-15

Herein, Au{sub nanoparticle}@mSiO{sub 2}@Y{sub 2}O{sub 3}:Eu nanocomposites are synthesized through layer-by-layer assembly technology. Au{sub nanoparticle}@mSiO{sub 2} core–shell nanospheres were prepared at first in the presence of CTAB in aqueous solution system by the modified one-pot method. A chemical precipitation method and a succeeding calcination process were adopted to the growth of Y{sub 2}O{sub 3}:Eu shells on the surfaces of Au{sub nanoparticle}@mSiO{sub 2} core–shell nanospheres. The structure, morphology and composition of the nanocomposites were confirmed by XRD, TEM and UV–vis absorption spectrum. The prepared Au{sub nanoparticle}@mSiO{sub 2}@Y{sub 2}O{sub 3}:Eu nanocomposites have showed the emission intensity enhances to 6.23 times at 30 nm thickness of the silica spacer between the core of Au nanoparticle and the shell of Y{sub 2}O{sub 3}:Eu. According to the observations of fluorescent lifetime and the modeling of local electric field, the metal-enhanced and quenched fluorescence is closely related with the enhancement of excitation and radiative decay rate and the quenching by NRET comes as a result of competition between the distance-dependent mechanisms. This kind of multifunctional inorganic material will be widely used in electronics, biology and medical drug loading, etc. - Highlights: • Fabrication of Au{sub nanoparticle}@mSiO{sub 2}@Y{sub 2}O{sub 3}:Eu nanocomposites with core-spacer-shell structure. • The controllable fluorescence is achieved by adjusting the spacer thickness of silica. • The fluorescence enhancement is 6.23-fold at an optimal spacer thickness about 30 nm. • The metal-enhanced fluorescence mechanism is proposed.

Crowdsourcing step-by-step information extraction to enhance existing how-to videos

OpenAIRE

Nguyen, Phu Tran; Weir, Sarah; Guo, Philip J.; Miller, Robert C.; Gajos, Krzysztof Z.; Kim, Ju Ho

2014-01-01

Millions of learners today use how-to videos to master new skills in a variety of domains. But browsing such videos is often tedious and inefficient because video player interfaces are not optimized for the unique step-by-step structure of such videos. This research aims to improve the learning experience of existing how-to videos with step-by-step annotations. We first performed a formative study to verify that annotations are actually useful to learners. We created ToolScape, an interac...

Defining the cognitive enhancing properties of video games: Steps Towards Standardization and Translation.

Science.gov (United States)

Goodwin, Shikha Jain; Dziobek, Derek

2016-09-01

Ever since video games were available to the general public, they have intrigued brain researchers for many reasons. There is an enormous amount of diversity in the video game research, ranging from types of video games used, the amount of time spent playing video games, the definition of video gamer versus non-gamer to the results obtained after playing video games. In this paper, our goal is to provide a critical discussion of these issues, along with some steps towards generalization using the discussion of an article published by Clemenson and Stark (2005) as the starting point. The authors used a distinction between 2D versus 3D video games to compare their effects on the learning and memory in humans. The primary hypothesis of the authors is that the exploration of virtual environments while playing video games is a human correlate of environment enrichment. Authors found that video gamers performed better than the non-video gamers, and if non-gamers are trained on playing video gamers, 3D games provide better environment enrichment compared to 2D video games, as indicated by better memory scores. The end goal of standardization in video games is to be able to translate the field so that the results can be used for greater good.

3D video coding: an overview of present and upcoming standards

Science.gov (United States)

Merkle, Philipp; Müller, Karsten; Wiegand, Thomas

2010-07-01

An overview of existing and upcoming 3D video coding standards is given. Various different 3D video formats are available, each with individual pros and cons. The 3D video formats can be separated into two classes: video-only formats (such as stereo and multiview video) and depth-enhanced formats (such as video plus depth and multiview video plus depth). Since all these formats exist of at least two video sequences and possibly additional depth data, efficient compression is essential for the success of 3D video applications and technologies. For the video-only formats the H.264 family of coding standards already provides efficient and widely established compression algorithms: H.264/AVC simulcast, H.264/AVC stereo SEI message, and H.264/MVC. For the depth-enhanced formats standardized coding algorithms are currently being developed. New and specially adapted coding approaches are necessary, as the depth or disparity information included in these formats has significantly different characteristics than video and is not displayed directly, but used for rendering. Motivated by evolving market needs, MPEG has started an activity to develop a generic 3D video standard within the 3DVC ad-hoc group. Key features of the standard are efficient and flexible compression of depth-enhanced 3D video representations and decoupling of content creation and display requirements.

Biocompatible fluorescence-enhanced ZrO{sub 2}-CdTe quantum dot nanocomposite for in vitro cell imaging

Energy Technology Data Exchange (ETDEWEB)

Lu Zhisong; Zhu Zhihong; Zheng Xinting; Qiao Yan; Li Changming [School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457 (Singapore); Guo Jun, E-mail: ecmli@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue, 639798 (Singapore)

2011-04-15

With advances of quantum dots (QDs) in bioimaging applications, various materials have been used to coat QDs to reduce their nanotoxicity; however, the coating could introduce new toxic sources and quench the fluorescence in bioimaging applications. In this work, ZrO{sub 2}, an excellent ceramic material with low extinction coefficient and good biocompatibility, is utilized to coat CdTe QDs for the first time. Experimental results show that ZrO{sub 2}-QD nanocomposites with the size of {approx} 30 nm possess enhanced fluorescence emission, lower nanotoxicity and gradually increased fluorescence under 350 nm light illumination. After functionalization with folic acid, they were applied to label cultured HeLa cells effectively. Therefore, the ZrO{sub 2}-QD nanocomposites could be promising biocompatible nanomaterials with strong fluorescence emission to replace or complement QDs in biomedical applications.

Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

Science.gov (United States)

Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

2014-02-01

The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (P<0.0001). In a nutshell, ozone enhanced the remineralizing potential of nanohydroxyapatite, and laser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

Effective and efficient learning in the operating theater with intraoperative video-enhanced surgical procedure training

OpenAIRE

van Det, M.J.; Meijerink, W.J.; Hoff, C.; Middel, B.; Pierie, J.P.

2013-01-01

INtraoperative Video Enhanced Surgical procedure Training (INVEST) is a new training method designed to improve the transition from basic skills training in a skills lab to procedural training in the operating theater. Traditionally, the master-apprentice model (MAM) is used for procedural training in the operating theater, but this model lacks uniformity and efficiency at the beginning of the learning curve. This study was designed to investigate the effectiveness and efficiency of INVEST co...

Enhanced green fluorescent protein is a nearly ideal long-term expression tracer for hematopoietic stem cells, whereas DsRed-express fluorescent protein is not.

Science.gov (United States)

Tao, Wen; Evans, Barbara-Graham; Yao, Jing; Cooper, Scott; Cornetta, Kenneth; Ballas, Christopher B; Hangoc, Giao; Broxmeyer, Hal E

2007-03-01

Validated gene transfer and expression tracers are essential for elucidating functions of mammalian genes. Here, we have determined the suitability and unintended side effects of enhanced green fluorescent protein (EGFP) and DsRed-Express fluorescent protein as expression tracers in long-term hematopoietic stem cells (HSCs). Retrovirally transduced mouse bone marrow cells expressing either EGFP or DsRed-Express in single or mixed dual-color cell populations were clearly discerned by flow cytometry and fluorescence microscopy. The results from in vivo competitive repopulation assays demonstrated that EGFP-expressing HSCs were maintained nearly throughout the lifespan of the transplanted mice and retained long-term multilineage repopulating potential. All mice assessed at 15 months post-transplantation were EGFP positive, and, on average, 24% total peripheral white blood cells expressed EGFP. Most EGFP-expressing recipient mice lived at least 22 months. In contrast, Discosoma sp. red fluorescent protein (DsRed)-expressing donor cells dramatically declined in transplant-recipient mice over time, particularly in the competitive setting, in which mixed EGFP- and DsRed-expressing cells were cotransplanted. Moreover, under in vitro culture condition favoring preservation of HSCs, purified EGFP-expressing cells grew robustly, whereas DsRed-expressing cells did not. Therefore, EGFP has no detectable deteriorative effects on HSCs, and is nearly an ideal long-term expression tracer for hematopoietic cells; however, DsRed-Express fluorescent protein is not suitable for these cells.

The learning effect of intraoperative video-enhanced surgical procedure training.

Science.gov (United States)

van Det, M J; Meijerink, W J H J; Hoff, C; Middel, L J; Koopal, S A; Pierie, J P E N

2011-07-01

The transition from basic skills training in a skills lab to procedure training in the operating theater using the traditional master-apprentice model (MAM) lacks uniformity and efficiency. When the supervising surgeon performs parts of a procedure, training opportunities are lost. To minimize this intervention by the supervisor and maximize the actual operating time for the trainee, we created a new training method called INtraoperative Video-Enhanced Surgical Training (INVEST). Ten surgical residents were trained in laparoscopic cholecystectomy either by the MAM or with INVEST. Each trainee performed six cholecystectomies that were objectively evaluated on an Objective Structured Assessment of Technical Skills (OSATS) global rating scale. Absolute and relative improvements during the training curriculum were compared between the groups. A questionnaire evaluated the trainee's opinion on this new training method. Skill improvement on the OSATS global rating scale was significantly greater for the trainees in the INVEST curriculum compared to the MAM, with mean absolute improvement 32.6 versus 14.0 points and mean relative improvement 59.1 versus 34.6% (P=0.02). INVEST significantly enhances technical and procedural skill development during the early learning curve for laparoscopic cholecystectomy. Trainees were positive about the content and the idea of the curriculum.

Perceptual learning during action video game playing.

Science.gov (United States)

Green, C Shawn; Li, Renjie; Bavelier, Daphne

2010-04-01

Action video games have been shown to enhance behavioral performance on a wide variety of perceptual tasks, from those that require effective allocation of attentional resources across the visual scene, to those that demand the successful identification of fleetingly presented stimuli. Importantly, these effects have not only been shown in expert action video game players, but a causative link has been established between action video game play and enhanced processing through training studies. Although an account based solely on attention fails to capture the variety of enhancements observed after action game playing, a number of models of perceptual learning are consistent with the observed results, with behavioral modeling favoring the hypothesis that avid video game players are better able to form templates for, or extract the relevant statistics of, the task at hand. This may suggest that the neural site of learning is in areas where information is integrated and actions are selected; yet changes in low-level sensory areas cannot be ruled out. Copyright © 2009 Cognitive Science Society, Inc.

Incorporating user motivations to design for video tagging

NARCIS (Netherlands)

van Velsen, Lex Stefan; Melenhorst, M.S.

2009-01-01

User video tagging can enhance the indexing of large collections of videos, or can provide the basis for personalizing output. However, before the benefits of tagging can be reaped, users must be motivated to provide videos with tags. This article describes a two-stage study that aimed at collecting

Iterative Multiview Side Information for Enhanced Reconstruction in Distributed Video Coding

Directory of Open Access Journals (Sweden)

2009-03-01

Full Text Available Distributed video coding (DVC is a new paradigm for video compression based on the information theoretical results of Slepian and Wolf (SW and Wyner and Ziv (WZ. DVC entails low-complexity encoders as well as separate encoding of correlated video sources. This is particularly attractive for multiview camera systems in video surveillance and camera sensor network applications, where low complexity is required at the encoder. In addition, the separate encoding of the sources implies no communication between the cameras in a practical scenario. This is an advantage since communication is time and power consuming and requires complex networking. In this work, different intercamera estimation techniques for side information (SI generation are explored and compared in terms of estimating quality, complexity, and rate distortion (RD performance. Further, a technique called iterative multiview side information (IMSI is introduced, where the final SI is used in an iterative reconstruction process. The simulation results show that IMSI significantly improves the RD performance for video with significant motion and activity. Furthermore, DVC outperforms AVC/H.264 Intra for video with average and low motion but it is still inferior to the Inter No Motion and Inter Motion modes.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm{sup 3+}-Yb{sup 3+} doped optical fiber beyond plasmonics

Energy Technology Data Exchange (ETDEWEB)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K., E-mail: skbhadra@cgcri.res.in [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India)

2015-12-07

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb{sup 3+}) and Thulium (Tm{sup 3+}) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb{sup 3+}. Four times enhancement of Yb{sup 3+} emission of 900–1100 nm and Tm{sup 3+} upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs.

qF-SSOP: real-time optical property corrected fluorescence imaging

Science.gov (United States)

Valdes, Pablo A.; Angelo, Joseph P.; Choi, Hak Soo; Gioux, Sylvain

2017-01-01

Fluorescence imaging is well suited to provide image guidance during resections in oncologic and vascular surgery. However, the distorting effects of tissue optical properties on the emitted fluorescence are poorly compensated for on even the most advanced fluorescence image guidance systems, leading to subjective and inaccurate estimates of tissue fluorophore concentrations. Here we present a novel fluorescence imaging technique that performs real-time (i.e., video rate) optical property corrected fluorescence imaging. We perform full field of view simultaneous imaging of tissue optical properties using Single Snapshot of Optical Properties (SSOP) and fluorescence detection. The estimated optical properties are used to correct the emitted fluorescence with a quantitative fluorescence model to provide quantitative fluorescence-Single Snapshot of Optical Properties (qF-SSOP) images with less than 5% error. The technique is rigorous, fast, and quantitative, enabling ease of integration into the surgical workflow with the potential to improve molecular guidance intraoperatively. PMID:28856038

Social video content delivery

CERN Document Server

Wang, Zhi; Zhu, Wenwu

2016-01-01

This brief presents new architecture and strategies for distribution of social video content. A primary framework for socially-aware video delivery and a thorough overview of the possible approaches is provided. The book identifies the unique characteristics of socially-aware video access and social content propagation, revealing the design and integration of individual modules that are aimed at enhancing user experience in the social network context. The change in video content generation, propagation, and consumption for online social networks, has significantly challenged the traditional video delivery paradigm. Given the massive amount of user-generated content shared in online social networks, users are now engaged as active participants in the social ecosystem rather than as passive receivers of media content. This revolution is being driven further by the deep penetration of 3G/4G wireless networks and smart mobile devices that are seamlessly integrated with online social networking and media-sharing s...

Frequency division multiplexed multi-color fluorescence microscope system

Science.gov (United States)

Le, Vu Nam; Yang, Huai Dong; Zhang, Si Chun; Zhang, Xin Rong; Jin, Guo Fan

2017-10-01

Grayscale camera can only obtain gray scale image of object, while the multicolor imaging technology can obtain the color information to distinguish the sample structures which have the same shapes but in different colors. In fluorescence microscopy, the current method of multicolor imaging are flawed. Problem of these method is affecting the efficiency of fluorescence imaging, reducing the sampling rate of CCD etc. In this paper, we propose a novel multiple color fluorescence microscopy imaging method which based on the Frequency division multiplexing (FDM) technology, by modulating the excitation lights and demodulating the fluorescence signal in frequency domain. This method uses periodic functions with different frequency to modulate amplitude of each excitation lights, and then combine these beams for illumination in a fluorescence microscopy imaging system. The imaging system will detect a multicolor fluorescence image by a grayscale camera. During the data processing, the signal obtained by each pixel of the camera will be processed with discrete Fourier transform, decomposed by color in the frequency domain and then used inverse discrete Fourier transform. After using this process for signals from all of the pixels, monochrome images of each color on the image plane can be obtained and multicolor image is also acquired. Based on this method, this paper has constructed and set up a two-color fluorescence microscope system with two excitation wavelengths of 488 nm and 639 nm. By using this system to observe the linearly movement of two kinds of fluorescent microspheres, after the data processing, we obtain a two-color fluorescence dynamic video which is consistent with the original image. This experiment shows that the dynamic phenomenon of multicolor fluorescent biological samples can be generally observed by this method. Compared with the current methods, this method can obtain the image signals of each color at the same time, and the color video's frame

In vivo fluorescence enhanced optical tomography reconstruction of lung cancer of non immersed small animals

Science.gov (United States)

Hervé, L.; Koenig, A.; Da Silva, A.; Berger, M.; Boutet, J.; Dinten, J. M.; Peltié, P.; Rizo, P.

2007-02-01

Fluorescence enhanced diffuse optical tomography (fDOT) is envisioned to be useful to collect functional information from small animal models. For oncology applications, cancer-targeted fluorescent markers can be used as a surrogate of the cancer activity. We are developing a continuous wave fDOT bench intended to be integrated in systems dedicated to whole body small animal fluorescence analyses. The focus is currently put on the reconstruction of non immersed small animals imaged by a CCD camera. The reconstruction stage already corrects the tissue heterogeneity artifacts through the computation of an optical heterogeneity map. We will show how this formalism coupled with the determination of the animal boundaries performed by a laser scanner, can be used to manage non contact acquisitions. The time of reconstruction for a 10 × 9 laser source positions, 45 × 40 detector elements and 14 × 11 × 14 mesh voxels is typically 10 minutes on a 3GHz PCs corresponding to the acquisition time allowing the two tasks to be performed in parallel. The system is validated on an in vivo experiment performed on three healthy nude mice and a mouse bearing a lung tumor at 10, 12 and 14 days after implantation allowing the follow up of the disease. The 3D fluorescence reconstructions of this mouse are presented and the total fluorescence amounts are compared.

Video game players show more precise multisensory temporal processing abilities.

Science.gov (United States)

Donohue, Sarah E; Woldorff, Marty G; Mitroff, Stephen R

2010-05-01

Recent research has demonstrated enhanced visual attention and visual perception in individuals with extensive experience playing action video games. These benefits manifest in several realms, but much remains unknown about the ways in which video game experience alters perception and cognition. In the present study, we examined whether video game players' benefits generalize beyond vision to multisensory processing by presenting auditory and visual stimuli within a short temporal window to video game players and non-video game players. Participants performed two discrimination tasks, both of which revealed benefits for video game players: In a simultaneity judgment task, video game players were better able to distinguish whether simple visual and auditory stimuli occurred at the same moment or slightly offset in time, and in a temporal-order judgment task, they revealed an enhanced ability to determine the temporal sequence of multisensory stimuli. These results suggest that people with extensive experience playing video games display benefits that extend beyond the visual modality to also impact multisensory processing.

Semantic web technologies for video surveillance metadata

OpenAIRE

Poppe, Chris; Martens, Gaëtan; De Potter, Pieterjan; Van de Walle, Rik

2012-01-01

Video surveillance systems are growing in size and complexity. Such systems typically consist of integrated modules of different vendors to cope with the increasing demands on network and storage capacity, intelligent video analytics, picture quality, and enhanced visual interfaces. Within a surveillance system, relevant information (like technical details on the video sequences, or analysis results of the monitored environment) is described using metadata standards. However, different module...

Spectral enhancement of leucocrystal violet treated footwear impression evidence in blood.

Science.gov (United States)

Spence, Lindsay; Asmussen, Gary

2003-03-27

The results presented demonstrate the capacity for spectral enhancement to substantially improve the forensic examination of footwear impressions in blood treated with leucocrystal violet (LCV). The UV-Vis absorption spectra were generated of (i) an aqueous solution of leucocrystal violet, (ii) leucocrystal violet in 3% H(2)O(2), (iii) LCV working solution and (iv) whole blood added to LCV working solution. The resultant fluorescence emission spectra were subsequently generated (lambda(ex)=630nm, lambda(em)=661-900nm). The results indicate that the UV-Vis absorption spectra of an unbuffered solution of whole blood with LCV working solution produces a strong absorbance curve with a maxima at 630nm. Subsequent excitation at this wavelength and generation of the emission spectrum in the fluorescence mode indicates that a solution of whole blood added to LCV working solution is an extremely weak fluorophore. Therefore, to enable an adequate and timely enhancement of blood impression evidence treated with LCV utilising either visible fluorescence or infrared luminescence requires (i) selection of the most appropriate excitation wavelength (lambda(ex)) and emission wavelength (lambda(em)) with extremely narrow band pass filters, which in the absence of substrate matrix interference is excitation at 630nm producing the emission maxima at 665nm and (ii) a visual enhancement system such as a CCD colour IR video camera with image integration.

Interactive Video, The Next Step

Science.gov (United States)

Strong, L. R.; Wold-Brennon, R.; Cooper, S. K.; Brinkhuis, D.

2012-12-01

Video has the ingredients to reach us emotionally - with amazing images, enthusiastic interviews, music, and video game-like animations-- and it's emotion that motivates us to learn more about our new interest. However, watching video is usually passive. New web-based technology is expanding and enhancing the video experience, creating opportunities to use video with more direct interaction. This talk will look at an Educaton and Outreach team's experience producing video-centric curriculum using innovative interactive media tools from TED-Ed and FlixMaster. The Consortium for Ocean Leadership's Deep Earth Academy has partnered with the Center for Dark Energy Biosphere Investigations (C-DEBI) to send educators and a video producer aboard three deep sea research expeditions to the Juan de Fuca plate to install and service sub-seafloor observatories. This collaboration between teachers, students, scientists and media producers has proved a productive confluence, providing new ways of understanding both ground-breaking science and the process of science itself - by experimenting with new ways to use multimedia during ocean-going expeditions and developing curriculum and other projects post-cruise.

Real-time video quality monitoring

Science.gov (United States)

Liu, Tao; Narvekar, Niranjan; Wang, Beibei; Ding, Ran; Zou, Dekun; Cash, Glenn; Bhagavathy, Sitaram; Bloom, Jeffrey

2011-12-01

The ITU-T Recommendation G.1070 is a standardized opinion model for video telephony applications that uses video bitrate, frame rate, and packet-loss rate to measure the video quality. However, this model was original designed as an offline quality planning tool. It cannot be directly used for quality monitoring since the above three input parameters are not readily available within a network or at the decoder. And there is a great room for the performance improvement of this quality metric. In this article, we present a real-time video quality monitoring solution based on this Recommendation. We first propose a scheme to efficiently estimate the three parameters from video bitstreams, so that it can be used as a real-time video quality monitoring tool. Furthermore, an enhanced algorithm based on the G.1070 model that provides more accurate quality prediction is proposed. Finally, to use this metric in real-world applications, we present an example emerging application of real-time quality measurement to the management of transmitted videos, especially those delivered to mobile devices.

Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

Science.gov (United States)

Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

2016-05-01

Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

Ultratrace analysis of transuranic actinides by laser-induced fluorescence

Science.gov (United States)

Miller, S.M.

1983-10-31

Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

Combination of panoramic and fluorescence endoscopic images to obtain tumor spatial distribution information useful for bladder cancer detection

Science.gov (United States)

Olijnyk, S.; Hernández Mier, Y.; Blondel, W. C. P. M.; Daul, C.; Wolf, D.; Bourg-Heckly, G.

2007-07-01

Bladder cancer is widely spread. Moreover, carcinoma in situ can be difficult to diagnose as it may be difficult to see, and become invasive in 50 % of case. Non invasive diagnosis methods like photodynamic or autofluorescence endoscopy allow enhancing sensitivity and specificity. Besides, bladder tumors can be multifocal. Multifocality increases the probability of recurrence and infiltration into bladder muscle. Analysis of spatial distribution of tumors could be used to improve diagnosis. We explore the feasibility to combine fluorescence and spatial information on phantoms. We developed a system allowing the acquisition of consecutive images under white light or UV excitation alternatively and automatically along the video sequence. We also developed an automatic image processing algorithm to build a partial panoramic image from a cystoscopic sequence of images. Fluorescence information is extracted from wavelength bandpass filtered images and superimposed over the cartography. Then, spatial distribution measures of fluorescent spots can be computed. This cartography can be positioned on a 3D generic shape of bladder by selecting some reference points. Our first results on phantoms show that it is possible to obtain cartography with fluorescent spots and extract quantitative information of their spatial distribution on a "wide" field of view basis.

Fluorescent screens and image processing for the APS linac test stand

International Nuclear Information System (INIS)

Berg, W.; Ko, K.

1992-01-01

A fluorescent screen was used to monitor relative beam position and spot size of a 56-MeV electron beam in the linac test stand. A chromium doped alumina ceramic screen inserted into the beam was monitored by a video camera. The resulting image was captured using a frame grabber and stored into memory. Reconstruction and analysis of the stored image was performed using PV-WAVE. This paper will discuss the hardware and software implementation of the fluorescent screen and imaging system. Proposed improvements for the APS linac fluorescent screens and image

Spatially controlled fabrication of a bright fluorescent nanodiamond-array with enhanced far-red Si-V luminescence.

Science.gov (United States)

Singh, Sonal; Thomas, Vinoy; Martyshkin, Dmitry; Kozlovskaya, Veronika; Kharlampieva, Eugenia; Catledge, Shane A

2014-01-31

We demonstrate a novel approach to precisely pattern fluorescent nanodiamond-arrays with enhanced far-red intense photostable luminescence from silicon-vacancy (Si-V) defect centers. The precision-patterned pre-growth seeding of nanodiamonds is achieved by a scanning probe 'dip-pen' nanolithography technique using electrostatically driven transfer of nanodiamonds from 'inked' cantilevers to a UV-treated hydrophilic SiO2 substrate. The enhanced emission from nanodiamond dots in the far-red is achieved by incorporating Si-V defect centers in a subsequent chemical vapor deposition treatment. The development of a suitable nanodiamond ink and mechanism of ink transport, and the effect of humidity and dwell time on nanodiamond patterning are investigated. The precision patterning of as-printed (pre-CVD) arrays with dot diameter and dot height as small as 735 nm ± 27 nm and 61 nm ± 3 nm, respectively, and CVD-treated fluorescent ND-arrays with consistently patterned dots having diameter and height as small as 820 nm ± 20 nm and, 245 nm ± 23 nm, respectively, using 1 s dwell time and 30% RH is successfully achieved. We anticipate that the far-red intense photostable luminescence (~738 nm) observed from Si-V defect centers integrated in spatially arranged nanodiamonds could be beneficial for the development of next generation fluorescence-based devices and applications.

Silver nanoparticles enhanced 1.53 µm band fluorescence of Er{sup 3+}/Yb{sup 3+} codoped tellurite glasses

Energy Technology Data Exchange (ETDEWEB)

Qi, Yawei; Zhou, Yaxun, E-mail: zhouyaxun@nbu.edu.cn; Wu, Libo; Yang, Fengjing; Peng, Shengxi; Zheng, Shichao; Yin, Dandan

2014-09-15

The silver nanoparticles (NPs) was introduced into the Er{sup 3+}/Yb{sup 3+} codoped tellurite glasses with composition of TeO{sub 2}–ZnO to improve the 1.53 µm band fluorescence of Er{sup 3+} and the thermal stability of glass host. The UV–Vis–NIR absorption spectra, 1.53 µm band fluorescence spectra and fluorescence decaying curves, the differential scanning calorimeter (DSC) curves, X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images of glass samples were characterized to investigate the effect of silver NPs on the fluorescence properties of Er{sup 3+}, thermal stability and structure behavior of glass host. It is shown that the Er{sup 3+}/Yb{sup 3+} codoped tellurite glass emits intense 1.53 µm band fluorescence with peak wavelength located at about 1532 nm under the 980 nm excitation. The introduction of silver NPs further improves the fluorescence intensity of Er{sup 3+} which is attributed to the enhanced local electric field effect induced by localized surface Plasmon resonance (LSPR) of silver NPs and the possible energy transfer from silver NPs to Er{sup 3+}. An improvement by about 62% of 1.5{sup 3} µm band fluorescence intensity was found in the studied Er{sup 3+}/Yb{sup 3+} codoped tellurite glass containing 0.5 mol% amount of AgNO{sub 3}. In addition, the thermal stability of glass host increases with the introduction of silver NPs while the glass structure maintains the amorphous nature. The present results indicate that the prepared Er{sup 3+}/Yb{sup 3+} codoped tellurite glass with an appropriate amount of silver NPs has good prospect as a gain medium applied for 1.53 µm band broad and high-gain erbium-doped fiber amplifiers (EDFAs). - Highlights: • Tellurite glass with Er{sup 3+}/Yb{sup 3+} and silver NPs was prepared by melt-quenching method. • Silver NPs with average size of 12 nm and Plasmon band at 560 nm was observed. • Addition of silver NPs increased the thermal stability of tellurite glass. �

Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles

OpenAIRE

Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D.; Chang, Huan-Cheng; Ye, Jing Yong

2012-01-01

Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photo...

Quantifying sublethal effects of glyphosate and Roundup® to Daphnia magna using a fluorescence based enzyme activity assay and video tracking

DEFF Research Database (Denmark)

Roslev, Peter; R. Hansen, Lone; Ørsted, Michael

Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum, non-selective herbicide formulations. The toxicity of this herbicide to non-target aquatic organisms such as Daphnia magna is often evaluated using conventional toxicity assays that focus...... on endpoints such as immobility and mortality. In this study, we investigated sublethal effects of glyphosate and Roundup® to D. magna using video tracking for quantifying behavioral changes, and a novel fluorescence based assay for measuring in vivo hydrolytic enzyme activity (FLEA assay). Roundup® exposure...... resulted in concentration-dependent inhibition of alkaline phosphatase activity in D. magna. The inhibition of alkaline phosphatase by Roundup® was temperature-dependent with lowest inhibition at 14 °C and greater inhibition at 20 and 26 °C. Exposure of D. magna to sublethal concentrations of glyphosate...

Video Conferencing for a Virtual Seminar Room

DEFF Research Database (Denmark)

Forchhammer, Søren; Fosgerau, A.; Hansen, Peter Søren K.

2002-01-01

A PC-based video conferencing system for a virtual seminar room is presented. The platform is enhanced with DSPs for audio and video coding and processing. A microphone array is used to facilitate audio based speaker tracking, which is used for adaptive beam-forming and automatic camera...

Learning computer science by watching video games

OpenAIRE

Nagataki, Hiroyuki

2014-01-01

This paper proposes a teaching method that utilizes video games in computer science education. The primary characteristic of this approach is that it utilizes video games as observational materials. The underlying idea is that by observing the computational behavior of a wide variety of video games, learners will easily grasp the fundamental architecture, theory, and technology of computers. The results of a case study conducted indicate that the method enhances the motivation of students for...

Earlier visual N1 latencies in expert video-game players: a temporal basis of enhanced visuospatial performance?

Science.gov (United States)

Latham, Andrew J; Patston, Lucy L M; Westermann, Christine; Kirk, Ian J; Tippett, Lynette J

2013-01-01

Increasing behavioural evidence suggests that expert video game players (VGPs) show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG) recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT) in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years). Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented). IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction.

Earlier visual N1 latencies in expert video-game players: a temporal basis of enhanced visuospatial performance?

Directory of Open Access Journals (Sweden)

Andrew J Latham

Full Text Available Increasing behavioural evidence suggests that expert video game players (VGPs show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years. Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented. IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction.

Video Game Players Show More Precise Multisensory Temporal Processing Abilities

OpenAIRE

Donohue, Sarah E.; Woldorff, Marty G.; Mitroff, Stephen R.

2010-01-01

Recent research has demonstrated enhanced visual attention and visual perception in individuals with extensive experience playing action video games. These benefits manifest in several realms, but much remains unknown about the ways in which video game experience alters perception and cognition. The current study examined whether video game players’ benefits generalize beyond vision to multisensory processing by presenting video game players and non-video game players auditory and visual stim...

Fluorescent Angiography Used to Evaluate the Perfusion Status of Anastomosis in Laparoscopic Anterior Resection.

Science.gov (United States)

Koh, Frederick H; Tan, Ker-Kan

2016-12-01

Anastomotic leakage after gastrointestinal surgery is associated with significant morbidity and mortality.1 Insufficient vascular supply is one cause.2 Recent reports of using intraoperative indocyanine green (ICG) fluorescent angiography to evaluate whether perfusion of the anastomosis is adequate has yielded positive outcomes.3 - 6 The authors describe their use of ICG-enhanced fluorescence angiography in a laparoscopic anterior resection. The patient was an 80-year-old with an upper rectal adenocarcinoma and significant cardiovascular risk factors. Fluorescence angiography with 0.4 mg/kg of ICG was administered intravenously just before the colorectal anastomosis was fashioned. A near-infrared (NIR) laparoscopic camera (KARLSTORZ, GmbH & Co. KG, Tuttlingen, Germany) was used to inspect the anastomosis. For this video, 0.4 mg/kg of ICG also was injected after ligation of the inferior mesenteric artery to demonstrate the appearance of a poorly perfused sigmoid bowel. Just before the staple was fired to fashion the colorectal anastomosis, an intravenous bolus of ICG was administered. Within seconds, vessels on both ends of the anastomosis turned fluorescent blue, indicating adequacy of perfusion. The use of ICG did not significantly lengthen the operative time (285 min) because its effect appeared within seconds after its administration. The patient recovered well and was discharged on postoperative day 5. Another four patients who also underwent intraoperative fluorescent angiography for left-sided colorectal lesions did not experience anastomotic leakage. The study showed that ICG fluorescent angiography is a simple and quick intraoperative tool for evaluating the perfusion of the anastomosis. The authors' experience with ICG fluorescent angiography has shown promising results, with a 0 % anastomotic leak rate.

Multispectral system for medical fluorescence imaging

International Nuclear Information System (INIS)

Andersson, P.S.; Montan, S.; Svanberg, S.

1987-01-01

The principles of a powerful multicolor imaging system for tissue fluorescence diagnostics are discussed. Four individually spectrally filtered images are formed on a matrix detector by means of a split-mirror arrangement. The four images are processed in a computer, pixel by pixel, by means of mathematical operations, leading to an optimized contrast image, which enhances a selected feature. The system is being developed primarily for medical fluorescence imaging, but has wide applications in fluorescence, reflectance, and transmission monitoring related to a wide range of industrial and environmental problems. The system operation is described for the case of linear imaging on a diode array detector. Laser-induced fluorescence is used for cancer tumor and arteriosclerotic plaque demarcation using the contrast enhancement capabilities of this imaging system. Further examples of applications include fluorescing minerals and flames

Video astronomy on the go using video cameras with small telescopes

CERN Document Server

Ashley, Joseph

2017-01-01

Author Joseph Ashley explains video astronomy's many benefits in this comprehensive reference guide for amateurs. Video astronomy offers a wonderful way to see objects in far greater detail than is possible through an eyepiece, and the ability to use the modern, entry-level video camera to image deep space objects is a wonderful development for urban astronomers in particular, as it helps sidestep the issue of light pollution. The author addresses both the positive attributes of these cameras for deep space imaging as well as the limitations, such as amp glow. The equipment needed for imaging as well as how it is configured is identified with hook-up diagrams and photographs. Imaging techniques are discussed together with image processing (stacking and image enhancement). Video astronomy has evolved to offer great results and great ease of use, and both novices and more experienced amateurs can use this book to find the set-up that works best for them. Flexible and portable, they open up a whole new way...

Multisensor data fusion for enhanced respiratory rate estimation in thermal videos.

Science.gov (United States)

Pereira, Carina B; Xinchi Yu; Blazek, Vladimir; Venema, Boudewijn; Leonhardt, Steffen

2016-08-01

Scientific studies have demonstrated that an atypical respiratory rate (RR) is frequently one of the earliest and major indicators of physiological distress. However, it is also described in the literature as "the neglected vital parameter", mainly due to shortcomings of clinical available monitoring techniques, which require attachment of sensors to the patient's body. The current paper introduces a novel approach that uses multisensor data fusion for an enhanced RR estimation in thermal videos. It considers not only the temperature variation around nostrils and mouth, but the upward and downward movement of both shoulders. In order to analyze the performance of our approach, two experiments were carried out on five healthy candidates. While during phase A, the subjects breathed normally, during phase B they simulated different breathing patterns. Thoracic effort was the gold standard elected to validate our algorithm. Our results show an excellent agreement between infrared thermography (IRT) and ground truth. While in phase A a mean correlation of 0.983 and a root-mean-square error of 0.240 bpm (breaths per minute) was obtained, in phase B they hovered around 0.995 and 0.890 bpm, respectively. In sum, IRT may be a promising clinical alternative to conventional sensors. Additionally, multisensor data fusion contributes to an enhancement of RR estimation and robustness.

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....

Finding and Improving the Key-Frames of Long Video Sequences for Face Recognition

DEFF Research Database (Denmark)

Nasrollahi, Kamal; Moeslund, Thomas B.

2010-01-01

Face recognition systems are very sensitive to the quality and resolution of their input face images. This makes such systems unreliable when working with long surveillance video sequences without employing some selection and enhancement algorithms. On the other hand, processing all the frames...... of such video sequences by any enhancement or even face recognition algorithm is demanding. Thus, there is a need for a mechanism to summarize the input video sequence to a set of key-frames and then applying an enhancement algorithm to this subset. This paper presents a system doing exactly this. The system...... uses face quality assessment to select the key-frames and a hybrid super-resolution to enhance the face image quality. The suggested system that employs a linear associator face recognizer to evaluate the enhanced results has been tested on real surveillance video sequences and the experimental results...

Fluorescent scattering by molecules embedded in small particles

International Nuclear Information System (INIS)

1982-01-01

Studies are reported in these areas: double resonance in fluorescent and Raman scattering; surface enhanced Raman scattering; fluorescence by molecules embedded in small particles; fluorescence by a liquid droplet; and fluorescence by conical pits in surfaces

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

Science.gov (United States)

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

2017-02-01

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

Resolution enhancement of low quality videos using a high-resolution frame

NARCIS (Netherlands)

Pham, T.Q.; Van Vliet, L.J.; Schutte, K.

2006-01-01

This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of

Students' and Teachers' Perceptions of Using Video Games to Enhance Science Instruction

Science.gov (United States)

Marino, Matthew T.; Israel, Maya; Beecher, Constance C.; Basham, James D.

2013-10-01

Science education video game research points toward promising, but inconclusive results in both student learning outcomes and attitudes. However, student-level variables other than gender have been largely absent from this research. This study examined how students' reading ability level and disability status are related to their video game-playing behaviors outside of school and their perceptions about the use of science video games during school. Thirty-four teachers and 876 sixth- through ninth-grade students from 14 states participated in the study. All student groups reported that they would prefer to learn science from a video game rather than from traditional text, laboratory-based, or Internet environments. Chi-square analyses indicated a significant association between reading ability level, disability status, and key areas of interest including students' use of video games outside of school, their perceptions of their scientific abilities, and whether they would pursue a career in the sciences. Implications of these findings and areas for future research are identified.

How musical are music video game players?

Science.gov (United States)

Pasinski, Amanda C; Hannon, Erin E; Snyder, Joel S

2016-10-01

Numerous studies have shown that formal musical training is associated with sensory, motor, and cognitive advantages in individuals of various ages. However, the nature of the observed differences between musicians and nonmusicians is poorly understood, and little is known about the listening skills of individuals who engage in alternative types of everyday musical activities. Here, we show that people who have frequently played music video games outperform nonmusicians controls on a battery of music perception tests. These findings reveal that enhanced musical aptitude can be found among individuals who play music video games, raising the possibility that music video games could potentially enhance music perception skills in individuals across a broad spectrum of society who are otherwise unable to invest the time and/or money required to learn a musical instrument.

Spatially controlled fabrication of a bright fluorescent nanodiamond-array with enhanced far-red Si-V luminescence

International Nuclear Information System (INIS)

Singh, Sonal; Thomas, Vinoy; Kharlampieva, Eugenia; Catledge, Shane A; Martyshkin, Dmitry; Kozlovskaya, Veronika

2014-01-01

We demonstrate a novel approach to precisely pattern fluorescent nanodiamond-arrays with enhanced far-red intense photostable luminescence from silicon-vacancy (Si-V) defect centers. The precision-patterned pre-growth seeding of nanodiamonds is achieved by a scanning probe ‘dip-pen’ nanolithography technique using electrostatically driven transfer of nanodiamonds from ‘inked’ cantilevers to a UV-treated hydrophilic SiO 2 substrate. The enhanced emission from nanodiamond dots in the far-red is achieved by incorporating Si-V defect centers in a subsequent chemical vapor deposition treatment. The development of a suitable nanodiamond ink and mechanism of ink transport, and the effect of humidity and dwell time on nanodiamond patterning are investigated. The precision patterning of as-printed (pre-CVD) arrays with dot diameter and dot height as small as 735 nm ± 27 nm and 61 nm ± 3 nm, respectively, and CVD-treated fluorescent ND-arrays with consistently patterned dots having diameter and height as small as 820 nm ± 20 nm and, 245 nm ± 23 nm, respectively, using 1 s dwell time and 30% RH is successfully achieved. We anticipate that the far-red intense photostable luminescence (∼738 nm) observed from Si-V defect centers integrated in spatially arranged nanodiamonds could be beneficial for the development of next generation fluorescence-based devices and applications. (paper)

Determination of Protein by Fluorescence Enhancement of Curcumin in Lanthanum-Curcumin-Sodium Dodecyl Benzene Sulfonate-Protein System

Energy Technology Data Exchange (ETDEWEB)

Wang, Feng [Zaozhuang University, People' s Republic of China; Huang, Wei [Zaozhuang University, People' s Republic of China; Zhang, Yunfeng [Zaozhuang University, People' s Republic of China; Wang, Mingyin [Zaozhuang University, People' s Republic of China; Sun, Lina [Zaozhuang University, People' s Republic of China; Tang, Bo [Shandong University, Jinan, China; Wang, Wei [ORNL

2011-01-01

We found that the fluorescence intensity of the lanthanum (La(3+))-curcumin (CU) complex can be highly enhanced by proteins in the presence of sodium dodecyl benzene sulphonate (SDBS). Based on this finding, a new fluorimetric method for the determination of protein was developed. Under optimized conditions, the enhanced intensities of fluorescence are quantitatively in proportion to the concentrations of proteins in the range 0.0080-20.0 g mL(-1) for bovine serum albumin (BSA) and 0.00080-20.0 g mL(-1) for human serum albumin (HSA) with excitation of 425 nm, and 0.00020-20.0 g mL(-1) for bovine serum albumin (BSA) and 0.00080-20.0 g mL(-1)for human serum albumin (HSA) with excitation of 280 nm, while corresponding qualitative detection limits (S/N 3) are as low as 5.368, 0.573, 0.049, 0.562 g mL(-1), respectively. Study on reaction mechanism reveals that proteins can bind with La(3+), CU and SDBS through self-assembling function with electrostatic attraction, hydrogen bonding, hydrophobic interaction and van der Waals forces, etc. The proteins form a supermolecular association with multilayer structure, in which La(3+)-CU is clamped between BSA and SDBS. The unique high fluorescence enhancement of CU is resulted through synergic effects of favorable hydrophobic microenvironment provided by BSA and SDBS, and efficient intermolecular energy transfer among BSA, SDBS and CU. In energy transfer process, La(3+) plays a crucial role because it not only shortens the distance between SDBS and CU, but also acts as a "bridge" for transferring the energy from BSA to CU.

Conversion of just-continuous metallic films to large particulate substrates for metal-enhanced fluorescence

OpenAIRE

Aslan, Kadir; Malyn, Stuart N.; Zhang, Yongxia; Geddes, Chris D.

2008-01-01

We report the effects of thermally annealing, non-, just-, and thick continuous silver films for their potential applications in metal-enhanced fluorescence, a near-field concept which can alter the free-space absorption and emissive properties of close-proximity fluorophores (excited states). We have chosen to anneal a noncontinuous particulate film 5 nm thick and two thicker continuous films, 15 and 25 nm thick, respectively. Our results show that the annealing of the 25 nm film has little ...

Fingerprint enhancement revisited and the effects of blood enhancement chemicals on subsequent profiler Plus fluorescent short tandem repeat DNA analysis of fresh and aged bloody fingerprints.

Science.gov (United States)

Frégeau, C J; Germain, O; Fourney, R M

2000-03-01

This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S 1358, HumvWA, Hum

Dynamic Video Streaming in Caching-enabled Wireless Mobile Networks

OpenAIRE

Liang, C.; Hu, S.

2017-01-01

Recent advances in software-defined mobile networks (SDMNs), in-network caching, and mobile edge computing (MEC) can have great effects on video services in next generation mobile networks. In this paper, we jointly consider SDMNs, in-network caching, and MEC to enhance the video service in next generation mobile networks. With the objective of maximizing the mean measurement of video quality, an optimization problem is formulated. Due to the coupling of video data rate, computing resource, a...

Fluorescence enhancement effect for the determination of curcumin with yttrium(III)-curcumin-sodium dodecyl benzene sulfonate system

International Nuclear Information System (INIS)

Wang Feng; Huang Wei; Wang Yanwei

2008-01-01

It is found that the fluorescence of curcumin is greatly enhanced by yttrium(III) (Y 3+ ) in the presence of sodium dodecyl benzene sulfonate. Based on this, a sensitive fluorimetric method for the determination of curcumin in aqueous solution is proposed. In the potassium hydrogen phthalate (KHP) buffer, the fluorescence intensity of curcumin is proportional to the concentration of curcumin in the range of 7.37x10 -4 -0.18, 0.18-2.95 μg mL -1 and the detection limit is 0.1583 ng mL -1 . The actual samples are satisfactorily determined. In addition, the interaction mechanism is also studied

Adaptive live multicast video streaming of SVC with UEP FEC

Science.gov (United States)

Lev, Avram; Lasry, Amir; Loants, Maoz; Hadar, Ofer

2014-09-01

Ideally, video streaming systems should provide the best quality video a user's device can handle without compromising on downloading speed. In this article, an improved video transmission system is presented which dynamically enhances the video quality based on a user's current network state and repairs errors from data lost in the video transmission. The system incorporates three main components: Scalable Video Coding (SVC) with three layers, multicast based on Receiver Layered Multicast (RLM) and an UnEqual Forward Error Correction (FEC) algorithm. The SVC provides an efficient method for providing different levels of video quality, stored as enhancement layers. In the presented system, a proportional-integral-derivative (PID) controller was implemented to dynamically adjust the video quality, adding or subtracting quality layers as appropriate. In addition, an FEC algorithm was added to compensate for data lost in transmission. A two dimensional FEC was used. The FEC algorithm came from the Pro MPEG code of practice #3 release 2. Several bit errors scenarios were tested (step function, cosine wave) with different bandwidth size and error values were simulated. The suggested scheme which includes SVC video encoding with 3 layers over IP Multicast with Unequal FEC algorithm was investigated under different channel conditions, variable bandwidths and different bit error rates. The results indicate improvement of the video quality in terms of PSNR over previous transmission schemes.

Determination of fluoxetine in pharmaceutical and biological samples based on the silver nanoparticle enhanced fluorescence of fluoxetine-terbium complex.

Science.gov (United States)

Lotfi, Ali; Manzoori, Jamshid L

2016-11-01

In this study, a simple and sensitive spectrofluorimetric method is presented for the determination of fluoxetine based on the enhancing effect of silver nanoparticles (AgNPs) on the terbium-fluoxetine fluorescence emission. The AgNPs were prepared by a simple reduction method and characterized by UV-Vis spectroscopy and transmission electron microscopy. It was indicated that these AgNPs have a remarkable amplifying effect on the terbium-sensitized fluorescence of fluoxetine. The effects of various parameters such as AgNP and Tb 3+ concentration and the pH of the media were investigated. Under obtained optimal conditions, the fluorescence intensity of the terbium-fluoxetine-AgNP system was enhanced linearly by increasing the concentration of fluoxetine in the range of 0.008 to 19 mg/L. The limit of detection (b + 3s) was 8.3 × 10 -4 mg/L. The interference effects of common species found in real samples were also studied. The method had good linearity, recovery, reproducibility and sensitivity, and was satisfactorily applied for the determination of fluoxetine in tablet formulations, human urine and plasma samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Enhanced speed in fluorescence imaging using beat frequency multiplexing

Science.gov (United States)

Mikami, Hideharu; Kobayashi, Hirofumi; Wang, Yisen; Hamad, Syed; Ozeki, Yasuyuki; Goda, Keisuke

2016-03-01

Fluorescence imaging using radiofrequency-tagged emission (FIRE) is an emerging technique that enables higher imaging speed (namely, temporal resolution) in fluorescence microscopy compared to conventional fluorescence imaging techniques such as confocal microscopy and wide-field microscopy. It works based on the principle that it uses multiple intensity-modulated fields in an interferometric setup as excitation fields and applies frequency-division multiplexing to fluorescence signals. Unfortunately, despite its high potential, FIRE has limited imaging speed due to two practical limitations: signal bandwidth and signal detection efficiency. The signal bandwidth is limited by that of an acousto-optic deflector (AOD) employed in the setup, which is typically 100-200 MHz for the spectral range of fluorescence excitation (400-600 nm). The signal detection efficiency is limited by poor spatial mode-matching between two interfering fields to produce a modulated excitation field. Here we present a method to overcome these limitations and thus to achieve higher imaging speed than the prior version of FIRE. Our method achieves an increase in signal bandwidth by a factor of two and nearly optimal mode matching, which enables the imaging speed limited by the lifetime of the target fluorophore rather than the imaging system itself. The higher bandwidth and better signal detection efficiency work synergistically because higher bandwidth requires higher signal levels to avoid the contribution of shot noise and amplifier noise to the fluorescence signal. Due to its unprecedentedly high-speed performance, our method has a wide variety of applications in cancer detection, drug discovery, and regenerative medicine.

Gold Nanoparticle-Based Detection of Hg(II) in an Aqueous Solution: Fluorescence Quenching and Surface-Enhanced Raman Scattering Study

International Nuclear Information System (INIS)

Ganbold, Erdene Ochir; Park, Jin Ho; Ock, Kwang Su; Joo, Sang Woo

2011-01-01

We studied the detection of the Hg(II) concentration in an aqueous solution using rhodamine dyes on citrate-reduced Au nanoparticles (NPs). The quenching effect from Au NPs was found to decrease as the Hg(II) concentration increased under our experimental conditions. As the fluorescence signals intensified, the surface-enhanced Raman scattering (SERS) intensities reduced on the contrary due to less rhodamine dyes on Au NPs as the Hg(II) concentration increased. The rhodamine 6G (Rh6G) and rhodamine 123 (Rh123) dyes were examined via fluorescence and SERS measurements depending on Hg(II) concentrations. Fast and easy fluorescence detection of an Hg (II) concentration as low as a few ppm could be achieved by naked eye using citrate-reduced Au NPs

Video Chat with Multiple Cameras

OpenAIRE

MacCormick, John

2012-01-01

The dominant paradigm for video chat employs a single camera at each end of the conversation, but some conversations can be greatly enhanced by using multiple cameras at one or both ends. This paper provides the first rigorous investigation of multi-camera video chat, concentrating especially on the ability of users to switch between views at either end of the conversation. A user study of 23 individuals analyzes the advantages and disadvantages of permitting a user to switch between views at...

Resonant Scanning with Large Field of View Reduces Photobleaching and Enhances Fluorescence Yield in STED Microscopy.

Science.gov (United States)

Wu, Yong; Wu, Xundong; Lu, Rong; Zhang, Jin; Toro, Ligia; Stefani, Enrico

2015-10-01

Photobleaching is a major limitation of superresolution Stimulated Depletion Emission (STED) microscopy. Fast scanning has long been considered an effective means to reduce photobleaching in fluorescence microscopy, but a careful quantitative study of this issue is missing. In this paper, we show that the photobleaching rate in STED microscopy can be slowed down and the fluorescence yield be enhanced by scanning with high speed, enabled by using large field of view in a custom-built resonant-scanning STED microscope. The effect of scanning speed on photobleaching and fluorescence yield is more remarkable at higher levels of depletion laser irradiance, and virtually disappears in conventional confocal microscopy. With ≥6 GW∙cm(-2) depletion irradiance, we were able to extend the fluorophore survival time of Atto 647N and Abberior STAR 635P by ~80% with 8-fold wider field of view. We confirm that STED Photobleaching is primarily caused by the depletion light acting upon the excited fluorophores. Experimental data agree with a theoretical model. Our results encourage further increasing the linear scanning speed for photobleaching reduction in STED microscopy.

Fluorescent Endoscopy of Tumors in Upper Part of Gastrointestinal Tract

Science.gov (United States)

Borisova, E.; Vladimirov, B.; Angelov, I.; Avramov, L.

2007-04-01

In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus and stomach. The 5-ALA is administered per os six hours before measurements at dose 20mg/kg weight. High-power light-emitting diode at 405 nm is used as an excitation source. Special opto-mechanical device is built for LED to use the light guide of standard video-endoscopic system (Olimpus Corp.). Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer (USB4000, OceanOptics Inc.). Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

Developing Expertise: Using Video to Hone Teacher Candidates' Classroom Observation Skills

Science.gov (United States)

Cuthrell, Kristen; Steadman, Sharilyn C.; Stapleton, Joy; Hodge, Elizabeth

2016-01-01

This article explores the impact of a video observation model developed for teacher candidates in an early experiences course. Video Grand Rounds (VGR) combines a structured observation protocol, videos, and directed debriefing to enhance teacher candidates' observations skills within nonstructured and field-based observations. A comparative…

Educational Colonoscopy Video Enhances Bowel Preparation Quality and Comprehension in an Inner City Population.

Science.gov (United States)

Pillai, Ajish; Menon, Radha; Oustecky, David; Ahmad, Asyia

2017-07-24

Quality of bowel preparation and patient knowledge remains a major barrier for completing colorectal cancer screening. Few studies have tested unique ways to impact patient understanding centering on interactive computer programs, pictures, and brochures. Two studies explored instructional videos but focused on patient compliance and anxiety as endpoints. Furthermore, excessive video length and content may limit their impact on a broad patient population. No study so far has studied a video's impact on preparation quality and patient understanding of the colonoscopy procedure. We conducted a single blinded prospective study of inner city patients presenting for a first time screening colonoscopy. During their initial visit patients were randomized to watch an instructional colonoscopy video or a video discussing gastroesophageal reflux disease (GERD). All patients watched a 6 minutes long video with the same spokesperson, completed a demographic questionnaire (Supplemental Digital Content 1, http://links.lww.com/JCG/A352) and were enrolled only if screened within 30 days of their visit. On the day of the colonoscopy, patients completed a 14 question quiz of their knowledge. Blinded endoscopist graded patient preparations based on the Ottawa scale. All authors had access to the study data and reviewed and approved the final manuscript. Among the 104 subjects enrolled in the study, 56 were in the colonoscopy video group, 48 were in GERD video group, and 12 were excluded. Overall, 48% were male and 52% female; 90% of patients had less than a high school education, 76% were African American, and 67% used a 4 L split-dose preparation. There were no differences between either video group with regard to any of the above categories. Comparisons between the 2 groups revealed that the colonoscopy video group had significantly better Ottawa bowel preparation score (4.77 vs. 6.85; P=0.01) than the GERD video group. The colonoscopy video group also had less-inadequate repeat

High efficiency video coding (HEVC) algorithms and architectures

CERN Document Server

Budagavi, Madhukar; Sullivan, Gary

2014-01-01

This book provides developers, engineers, researchers and students with detailed knowledge about the High Efficiency Video Coding (HEVC) standard. HEVC is the successor to the widely successful H.264/AVC video compression standard, and it provides around twice as much compression as H.264/AVC for the same level of quality. The applications for HEVC will not only cover the space of the well-known current uses and capabilities of digital video – they will also include the deployment of new services and the delivery of enhanced video quality, such as ultra-high-definition television (UHDTV) and video with higher dynamic range, wider range of representable color, and greater representation precision than what is typically found today. HEVC is the next major generation of video coding design – a flexible, reliable and robust solution that will support the next decade of video applications and ease the burden of video on world-wide network traffic. This book provides a detailed explanation of the various parts ...

Standardized access, display, and retrieval of medical video

Science.gov (United States)

Bellaire, Gunter; Steines, Daniel; Graschew, Georgi; Thiel, Andreas; Bernarding, Johannes; Tolxdorff, Thomas; Schlag, Peter M.

1999-05-01

The system presented here enhances documentation and data- secured, second-opinion facilities by integrating video sequences into DICOM 3.0. We present an implementation for a medical video server extended by a DICOM interface. Security mechanisms conforming with DICOM are integrated to enable secure internet access. Digital video documents of diagnostic and therapeutic procedures should be examined regarding the clip length and size necessary for second opinion and manageable with today's hardware. Image sources relevant for this paper include 3D laparoscope, 3D surgical microscope, 3D open surgery camera, synthetic video, and monoscopic endoscopes, etc. The global DICOM video concept and three special workplaces of distinct applications are described. Additionally, an approach is presented to analyze the motion of the endoscopic camera for future automatic video-cutting. Digital stereoscopic video sequences are especially in demand for surgery . Therefore DSVS are also integrated into the DICOM video concept. Results are presented describing the suitability of stereoscopic display techniques for the operating room.

The impact of video technology on learning: A cooking skills experiment.

Science.gov (United States)

Surgenor, Dawn; Hollywood, Lynsey; Furey, Sinéad; Lavelle, Fiona; McGowan, Laura; Spence, Michelle; Raats, Monique; McCloat, Amanda; Mooney, Elaine; Caraher, Martin; Dean, Moira

2017-07-01

This study examines the role of video technology in the development of cooking skills. The study explored the views of 141 female participants on whether video technology can promote confidence in learning new cooking skills to assist in meal preparation. Prior to each focus group participants took part in a cooking experiment to assess the most effective method of learning for low-skilled cooks across four experimental conditions (recipe card only; recipe card plus video demonstration; recipe card plus video demonstration conducted in segmented stages; and recipe card plus video demonstration whereby participants freely accessed video demonstrations as and when needed). Focus group findings revealed that video technology was perceived to assist learning in the cooking process in the following ways: (1) improved comprehension of the cooking process; (2) real-time reassurance in the cooking process; (3) assisting the acquisition of new cooking skills; and (4) enhancing the enjoyment of the cooking process. These findings display the potential for video technology to promote motivation and confidence as well as enhancing cooking skills among low-skilled individuals wishing to cook from scratch using fresh ingredients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Label-Free Detection of Sequence-Specific DNA Based on Fluorescent Silver Nanoclusters-Assisted Surface Plasmon-Enhanced Energy Transfer.

Science.gov (United States)

Ma, Jin-Liang; Yin, Bin-Cheng; Le, Huynh-Nhu; Ye, Bang-Ce

2015-06-17

We have developed a label-free method for sequence-specific DNA detection based on surface plasmon enhanced energy transfer (SPEET) process between fluorescent DNA/AgNC string and gold nanoparticles (AuNPs). DNA/AgNC string, prepared by a single-stranded DNA template encoded two emitter-nucleation sequences at its termini and an oligo spacer in the middle, was rationally designed to produce bright fluorescence emission. The proposed method takes advantage of two strategies. The first one is the difference in binding properties of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) toward AuNPs. The second one is SPEET process between fluorescent DNA/AgNC string and AuNPs, in which fluorescent DNA/AgNC string can be spontaneously adsorbed onto the surface of AuNPs and correspondingly AuNPs serve as "nanoquencher" to quench the fluorescence of DNA/AgNC string. In the presence of target DNA, the sensing probe hybridized with target DNA to form duplex DNA, leading to a salt-induced AuNP aggregation and subsequently weakened SPEET process between fluorescent DNA/AgNC string and AuNPs. A red-to-blue color change of AuNPs and a concomitant fluorescence increase were clearly observed in the sensing system, which had a concentration dependent manner with specific DNA. The proposed method achieved a detection limit of ∼2.5 nM, offering the following merits of simple design, convenient operation, and low experimental cost because of no chemical modification, organic dye, enzymatic reaction, or separation procedure involved.

Fluorescence quantum yield measurements of fluorescent proteins: a laboratory experiment for a biochemistry or molecular biophysics laboratory course.

Science.gov (United States)

Wall, Kathryn P; Dillon, Rebecca; Knowles, Michelle K

2015-01-01

Fluorescent proteins are commonly used in cell biology to assess where proteins are within a cell as a function of time and provide insight into intracellular protein function. However, the usefulness of a fluorescent protein depends directly on the quantum yield. The quantum yield relates the efficiency at which a fluorescent molecule converts absorbed photons into emitted photons and it is necessary to know for assessing what fluorescent protein is the most appropriate for a particular application. In this work, we have designed an upper-level, biochemistry laboratory experiment where students measure the fluorescence quantum yields of fluorescent proteins relative to a standard organic dye. Four fluorescent protein variants, enhanced cyan fluorescent protein (ECFP), enhanced green fluorescent protein (EGFP), mCitrine, and mCherry, were used, however the methods described are useful for the characterization of any fluorescent protein or could be expanded to fluorescent quantum yield measurements of organic dye molecules. The laboratory is designed as a guided inquiry project and takes two, 4 hr laboratory periods. During the first day students design the experiment by selecting the excitation wavelength, choosing the standard, and determining the concentration needed for the quantum yield experiment that takes place in the second laboratory period. Overall, this laboratory provides students with a guided inquiry learning experience and introduces concepts of fluorescence biophysics into a biochemistry laboratory curriculum. © 2014 The International Union of Biochemistry and Molecular Biology.

Video-rate confocal microscopy for single-molecule imaging in live cells and superresolution fluorescence imaging.

Science.gov (United States)

Lee, Jinwoo; Miyanaga, Yukihiro; Ueda, Masahiro; Hohng, Sungchul

2012-10-17

There is no confocal microscope optimized for single-molecule imaging in live cells and superresolution fluorescence imaging. By combining the swiftness of the line-scanning method and the high sensitivity of wide-field detection, we have developed a, to our knowledge, novel confocal fluorescence microscope with a good optical-sectioning capability (1.0 μm), fast frame rates (fluorescence detection efficiency. Full compatibility of the microscope with conventional cell-imaging techniques allowed us to do single-molecule imaging with a great ease at arbitrary depths of live cells. With the new microscope, we monitored diffusion motion of fluorescently labeled cAMP receptors of Dictyostelium discoideum at both the basal and apical surfaces and obtained superresolution fluorescence images of microtubules of COS-7 cells at depths in the range 0-85 μm from the surface of a coverglass. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Review of the Effectiveness of Video Media in Instruction

Science.gov (United States)

1993-04-01

did beginners . This is consistent with the finding that directing attention to the relevant aspect of the video is more effective, because more...abstract or theoretical concepts with animated flowcharts or diagrams (Riches, 1990). Enhancing Practice. Animation can be used within interactive video and

Enhancing Secondary Science Content Accessibility with Video Games

Science.gov (United States)

Marino, Matthew T.; Becht, Kathleen M.; Vasquez, Eleazar, III; Gallup, Jennifer L.; Basham, James D.; Gallegos, Benjamin

2014-01-01

Mobile devices, including iPads, tablets, and so on, are common in high schools across the country. Unfortunately, many secondary teachers see these devices as distractions rather than tools for scaffolding instruction. This article highlights current research related to the use of video games as a means to increase the cognitive and social…

The Impact of Preservice Teachers' Experiences in a Video-Enhanced Training Program on Their Teaching: A Case Study in Physical Education

Science.gov (United States)

Gaudin, Cyrille; Chaliès, Sébastien; Amathieu, Jérôme

2018-01-01

This case study documents the influence of preservice teachers' experiences in a Video-Enhanced Training Program (VETP) on their teaching. The conceptual framework of this VETP comes from a research program in cultural anthropology based on Wittgenstein's analytical philosophy. Influence was identified during self-confrontation interviews with…

Enhancing maternal sensitivity and infant attachment security with video feedback: an exploratory study in Italy.

Science.gov (United States)

Cassibba, Rosalinda; Castoro, Germana; Costantino, Elisabetta; Sette, Giovanna; Van Ijzendoorn, Marinus H

2015-01-01

This study aims to explore whether a short-term and attachment-based video-feedback intervention, the Video-Feedback Intervention to Promote Positive Parenting With Discussions on the Representational Level (VIPP-R; F. Juffer, M.J. Bakermans-Kranenburg, & M.H. van IJzendoorn, 2008), might be effective in enhancing maternal sensitivity and in promoting infants' attachment security in an Italian sample of dyads with primiparous mothers. Moreover, we explore whether the effectiveness of VIPP-R might be different for parents with insecure attachment representations who might be most in need of preventive intervention, as compared to parents who already have a more balanced and secure state of mind. Thirty-two infants (40% female) and their mothers participated in the study. The sample was divided into an intervention group (n = 16) and a comparison group (n = 16). At 6 and 13 months of age, the Adult Attachment Interview (AAI; M. Main, N. Kaplan, & J. Cassidy, 1985) was administered. Moreover, a 30-min mother-infant play situation was videotaped and coded for maternal sensitivity with the Emotional Availability Scales (Z. Biringen, J. Robinson, & R.N. Emde, 2000). At 13 months of age, the Strange Situation Procedure (M.D.S. Ainsworth, M.D. Blehar, E. Waters, & S. Wall, 1978) was used to assess the security of mother-infant attachment. Results revealed a significant interaction effect between intervention and AAI security for infant attachment security; moreover, main effects of AAI security and intervention for maternal sensitivity were found. The VIPP-R appears effective in enhancing maternal sensitivity and infant attachment security, although only mothers with an insecure attachment representation may benefit from the intervention. © 2014 Michigan Association for Infant Mental Health.

The use of animation video in teaching to enhance the imagination and visualization of student in engineering drawing

Science.gov (United States)

Ismail M., E.; Mahazir I., Irwan; Othman, H.; Amiruddin M., H.; Ariffin, A.

2017-05-01

The rapid development of information technology today has given a new breath toward usage of computer in education. One of the increasingly popular nowadays is a multimedia technology that merges a variety of media such as text, graphics, animation, video and audio controlled by a computer. With this technology, a wide range of multimedia element can be developed to improve the quality of education. For that reason, this study aims to investigate the use of multimedia element based on animated video that was developed for Engineering Drawing subject according to the syllabus of Vocational College of Malaysia. The design for this study was a survey method using a quantitative approach and involved 30 respondents from Industrial Machining students. The instruments used in study is questionnaire with correlation coefficient value (0.83), calculated on Alpha-Cronbach. Data was collected and analyzed descriptive analyzed using SPSS. The study found that multimedia element for animation video was use significant have capable to increase imagination and visualization of student. The implications of this study provide information of use of multimedia element will student effect imagination and visualization. In general, these findings contribute to the formation of multimedia element of materials appropriate to enhance the quality of learning material for engineering drawing.

The Association Between Video Game Play and Cognitive Function: Does Gaming Platform Matter?

Science.gov (United States)

Huang, Vivian; Young, Michaelia; Fiocco, Alexandra J

2017-11-01

Despite consumer growth, few studies have evaluated the cognitive effects of gaming using mobile devices. This study examined the association between video game play platform and cognitive performance. Furthermore, the differential effect of video game genre (action versus nonaction) was explored. Sixty undergraduate students completed a video game experience questionnaire, and we divided them into three groups: mobile video game players (MVGPs), console/computer video game players (CVGPs), and nonvideo game players (NVGPs). Participants completed a cognitive battery to assess executive function, and learning and memory. Controlling for sex and ethnicity, analyses showed that frequent video game play is associated with enhanced executive function, but not learning and memory. MVGPs were significantly more accurate on working memory performances than NVGPs. Both MVGPs and CVGPs were similarly associated with enhanced cognitive function, suggesting that platform does not significantly determine the benefits of frequent video game play. Video game platform was found to differentially associate with preference for action video game genre and motivation for gaming. Exploratory analyses show that sex significantly effects frequent video game play, platform and genre preference, and cognitive function. This study represents a novel exploration of the relationship between mobile video game play and cognition and adds support to the cognitive benefits of frequent video game play.

Resolution enhancement of low-quality videos using a high-resolution frame

Science.gov (United States)

Pham, Tuan Q.; van Vliet, Lucas J.; Schutte, Klamer

2006-01-01

This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of corresponding LR-HR pairs of image patches from the HR still image, high-frequency details are transferred from the HR source to the LR video. The DCT-domain algorithm is much faster than example-based SR in spatial domain 6 because of a reduction in search dimensionality, which is a direct result of the compact and uncorrelated DCT representation. Fast searching techniques like tree-structure vector quantization 16 and coherence search1 are also key to the improved efficiency. Preliminary results on MJPEG sequence show promising result of the DCT-domain SR synthesis approach.

Gold nanoparticle enhanced fluorescence anisotropy for the assay of single nucleotide polymorphisms (SNPs) based on toehold-mediated strand-displacement reaction.

Science.gov (United States)

Wang, Xinyi; Zou, Mingjian; Huang, Hongduan; Ren, Yuqian; Li, Limei; Yang, Xiaoda; Li, Na

2013-03-15

We developed a highly differentiating, homogeneous gold nanoparticle (AuNP) enhanced fluorescence anisotropic method for single nucleotide polymorphism (SNP) detection at nanomolar level using toehold-mediated strand-displacement reaction. The template strand, containing a toehold domain with an allele-specific site, was immobilized on the surface of AuNPs, and the solution fluorescence anisotropy was markedly enhanced when the fluorescein-labeled blocking DNA was attached to the AuNP via hybridization. Strand-displacement by the target ssDNA strand resulted in detachment of fluorescein-labeled DNA from AuNPs, and thus decreased fluorescence anisotropy. The drastic kinetic difference in strand-displacement from toehold design was used to distinguish between the perfectly matched and the single-base mismatched strands. Free energy changes were calculated to elucidate the dependence of the differentiation ability on the mutation site in the toehold region. A solid negative signal change can be obtained for single-base mismatched strand in the dynamic range of the calibration curve, and a more than 10-fold signal difference can still be observed in a mixed solution containing 100 times the single-base mismatched strand, indicating the good specificity of the method. This proposed method can be performed with a standard spectrofluorimeter in a homogeneous and cost-effective manner, and has the potential to be extended to the application of fluorescence anisotropy method of SNP detection. Copyright © 2012 Elsevier B.V. All rights reserved.

Fast-track video-assisted thoracoscopic surgery

DEFF Research Database (Denmark)

Holbek, Bo Laksafoss; Petersen, René Horsleben; Kehlet, Henrik

2016-01-01

Objectives To provide a short overview of fast-track video-assisted thoracoscopic surgery (VATS) and to identify areas requiring further research. Design A literature search was made using key words including: fast-track, enhanced recovery, video-assisted thoracoscopic surgery, robot......-assisted thoracoscopic surgery (RATS), robotic, thoracotomy, single-incision, uniportal, natural orifice transluminal endoscopic surgery (NOTES), chest tube, air-leak, digital drainage, pain management, analgesia, perioperative management, anaesthesia and non-intubated. References from articles were screened for further...

Layer-based buffer aware rate adaptation design for SHVC video streaming

Science.gov (United States)

Gudumasu, Srinivas; Hamza, Ahmed; Asbun, Eduardo; He, Yong; Ye, Yan

2016-09-01

This paper proposes a layer based buffer aware rate adaptation design which is able to avoid abrupt video quality fluctuation, reduce re-buffering latency and improve bandwidth utilization when compared to a conventional simulcast based adaptive streaming system. The proposed adaptation design schedules DASH segment requests based on the estimated bandwidth, dependencies among video layers and layer buffer fullness. Scalable HEVC video coding is the latest state-of-art video coding technique that can alleviate various issues caused by simulcast based adaptive video streaming. With scalable coded video streams, the video is encoded once into a number of layers representing different qualities and/or resolutions: a base layer (BL) and one or more enhancement layers (EL), each incrementally enhancing the quality of the lower layers. Such layer based coding structure allows fine granularity rate adaptation for the video streaming applications. Two video streaming use cases are presented in this paper. The first use case is to stream HD SHVC video over a wireless network where available bandwidth varies, and the performance comparison between proposed layer-based streaming approach and conventional simulcast streaming approach is provided. The second use case is to stream 4K/UHD SHVC video over a hybrid access network that consists of a 5G millimeter wave high-speed wireless link and a conventional wired or WiFi network. The simulation results verify that the proposed layer based rate adaptation approach is able to utilize the bandwidth more efficiently. As a result, a more consistent viewing experience with higher quality video content and minimal video quality fluctuations can be presented to the user.

Implementation of smart phone video plethysmography and dependence on lighting parameters.

Science.gov (United States)

Fletcher, Richard Ribón; Chamberlain, Daniel; Paggi, Nicholas; Deng, Xinyue

2015-08-01

The remote measurement of heart rate (HR) and heart rate variability (HRV) via a digital camera (video plethysmography) has emerged as an area of great interest for biomedical and health applications. While a few implementations of video plethysmography have been demonstrated on smart phones under controlled lighting conditions, it has been challenging to create a general scalable solution due to the large variability in smart phone hardware performance, software architecture, and the variable response to lighting parameters. In this context, we present a selfcontained smart phone implementation of video plethysmography for Android OS, which employs both stochastic and deterministic algorithms, and we use this to study the effect of lighting parameters (illuminance, color spectrum) on the accuracy of the remote HR measurement. Using two different phone models, we present the median HR error for five different video plethysmography algorithms under three different types of lighting (natural sunlight, compact fluorescent, and halogen incandescent) and variations in brightness. For most algorithms, we found the optimum light brightness to be in the range 1000-4000 lux and the optimum lighting types to be compact fluorescent and natural light. Moderate errors were found for most algorithms with some devices under conditions of low-brightness (4000 lux). Our analysis also identified camera frame rate jitter as a major source of variability and error across different phone models, but this can be largely corrected through non-linear resampling. Based on testing with six human subjects, our real-time Android implementation successfully predicted the measured HR with a median error of -0.31 bpm, and an inter-quartile range of 2.1bpm.

Real-Time Fluorescence Detection in Aqueous Systems by Combined and Enhanced Photonic and Surface Effects in Patterned Hollow Sphere Colloidal Photonic Crystals.

Science.gov (United States)

Zhong, Kuo; Wang, Ling; Li, Jiaqi; Van Cleuvenbergen, Stijn; Bartic, Carmen; Song, Kai; Clays, Koen

2017-05-16

Hollow sphere colloidal photonic crystals (HSCPCs) exhibit the ability to maintain a high refractive index contrast after infiltration of water, leading to extremely high-quality photonic band gap effects, even in an aqueous (physiological) environment. Superhydrophilic pinning centers in a superhydrophobic environment can be used to strongly confine and concentrate water-soluble analytes. We report a strategy to realize real-time ultrasensitive fluorescence detection in patterned HSCPCs based on strongly enhanced fluorescence due to the photonic band-edge effect combined with wettability differentiation in the superhydrophobic/superhydrophilic pattern. The orthogonal nature of the two strategies allows for a multiplicative effect, resulting in an increase of two orders of magnitude in fluorescence.

Saturated excitation of Fluorescence to quantify excitation enhancement in aperture antennas

KAUST Repository

Aouani, Heykel

2012-07-23

Fluorescence spectroscopy is widely used to probe the electromagnetic intensity amplification on optical antennas, yet measuring the excitation intensity amplification is a challenge, as the detected fluorescence signal is an intricate combination of excitation and emission. Here, we describe a novel approach to quantify the electromagnetic amplification in aperture antennas by taking advantage of the intrinsic non linear properties of the fluorescence process. Experimental measurements of the fundamental f and second harmonic 2f amplitudes of the fluorescence signal upon excitation modulation are used to quantify the electromagnetic intensity amplification with plasmonic aperture antennas. © 2012 Optical Society of America.

Saturated excitation of Fluorescence to quantify excitation enhancement in aperture antennas

KAUST Repository

Aouani, Heykel; Hostein, Richard; Mahboub, Oussama; Devaux, Eloï se; Rigneault, Hervé ; Ebbesen, Thomas W.; Wenger, Jé rô me

2012-01-01

Fluorescence spectroscopy is widely used to probe the electromagnetic intensity amplification on optical antennas, yet measuring the excitation intensity amplification is a challenge, as the detected fluorescence signal is an intricate combination of excitation and emission. Here, we describe a novel approach to quantify the electromagnetic amplification in aperture antennas by taking advantage of the intrinsic non linear properties of the fluorescence process. Experimental measurements of the fundamental f and second harmonic 2f amplitudes of the fluorescence signal upon excitation modulation are used to quantify the electromagnetic intensity amplification with plasmonic aperture antennas. © 2012 Optical Society of America.

Integrating Usability Evaluation into Model-Driven Video Game Development

OpenAIRE

Fernandez , Adrian; Insfran , Emilio; Abrahão , Silvia; Carsí , José ,; Montero , Emanuel

2012-01-01

Part 3: Short Papers; International audience; The increasing complexity of video game development highlights the need of design and evaluation methods for enhancing quality and reducing time and cost. In this context, Model-Driven Development approaches seem to be very promising since a video game can be obtained by transforming platform-independent models into platform-specific models that can be in turn transformed into code. Although this approach is started to being used for video game de...

Indexed Captioned Searchable Videos: A Learning Companion for STEM Coursework

Science.gov (United States)

Tuna, Tayfun; Subhlok, Jaspal; Barker, Lecia; Shah, Shishir; Johnson, Olin; Hovey, Christopher

2017-02-01

Videos of classroom lectures have proven to be a popular and versatile learning resource. A key shortcoming of the lecture video format is accessing the content of interest hidden in a video. This work meets this challenge with an advanced video framework featuring topical indexing, search, and captioning (ICS videos). Standard optical character recognition (OCR) technology was enhanced with image transformations for extraction of text from video frames to support indexing and search. The images and text on video frames is analyzed to divide lecture videos into topical segments. The ICS video player integrates indexing, search, and captioning in video playback providing instant access to the content of interest. This video framework has been used by more than 70 courses in a variety of STEM disciplines and assessed by more than 4000 students. Results presented from the surveys demonstrate the value of the videos as a learning resource and the role played by videos in a students learning process. Survey results also establish the value of indexing and search features in a video platform for education. This paper reports on the development and evaluation of ICS videos framework and over 5 years of usage experience in several STEM courses.

Enhancing Parent-Child Communication and Parental Self-Esteem With a Video-Feedback Intervention: Outcomes With Prelingual Deaf and Hard-of-Hearing Children.

Science.gov (United States)

Lam-Cassettari, Christa; Wadnerkar-Kamble, Meghana B; James, Deborah M

2015-07-01

Evidence on best practice for optimizing communication with prelingual deaf and hard-of-hearing (DHH) children is lacking. This study examined the effect of a family-focused psychosocial video intervention program on parent-child communication in the context of childhood hearing loss. Fourteen hearing parents with a prelingual DHH child (Mage = 2 years 8 months) completed three sessions of video interaction guidance intervention. Families were assessed in spontaneous free play interactions at pre and postintervention using the Emotional Availability (EA) Scales. The Rosenberg Self-esteem Scale was also used to assess parental report of self-esteem. Compared with nontreatment baselines, increases were shown in the EA subscales: parental sensitivity, parental structuring, parental nonhostility, child responsiveness, and child involvement, and in reported self-esteem at postintervention. Video-feedback enhances communication in families with prelingual DHH children and encourages more connected parent-child interaction. The results raise implications regarding the focus of early intervention strategies for prelingual DHH children. © The Author 2015. Published by Oxford University Press.

Playing Action Video Games Improves Visuomotor Control.

Science.gov (United States)

Li, Li; Chen, Rongrong; Chen, Jing

2016-08-01

Can playing action video games improve visuomotor control? If so, can these games be used in training people to perform daily visuomotor-control tasks, such as driving? We found that action gamers have better lane-keeping and visuomotor-control skills than do non-action gamers. We then trained non-action gamers with action or nonaction video games. After they played a driving or first-person-shooter video game for 5 or 10 hr, their visuomotor control improved significantly. In contrast, non-action gamers showed no such improvement after they played a nonaction video game. Our model-driven analysis revealed that although different action video games have different effects on the sensorimotor system underlying visuomotor control, action gaming in general improves the responsiveness of the sensorimotor system to input error signals. The findings support a causal link between action gaming (for as little as 5 hr) and enhancement in visuomotor control, and suggest that action video games can be beneficial training tools for driving. © The Author(s) 2016.

Video games as a tool to train visual skills.

Science.gov (United States)

Achtman, R L; Green, C S; Bavelier, D

2008-01-01

Adult brain plasticity, although possible, is often difficult to elicit. Training regimens in adults can produce specific improvements on the trained task without leading to general enhancements that would improve quality of life. This paper considers the case of playing action video games as a way to induce widespread enhancement in vision. We review the range of visual skills altered by action video game playing as well as the game components important in promoting visual plasticity. Further, we discuss what these results might mean in terms of rehabilitation for different patient populations.

Enhancing Scalability in On-Demand Video Streaming Services for P2P Systems

Directory of Open Access Journals (Sweden)

R. Arockia Xavier Annie

2012-01-01

Full Text Available Recently, many video applications like video telephony, video conferencing, Video-on-Demand (VoD, and so forth have produced heterogeneous consumers in the Internet. In such a scenario, media servers play vital role when a large number of concurrent requests are sent by heterogeneous users. Moreover, the server and distributed client systems participating in the Internet communication have to provide suitable resources to heterogeneous users to meet their requirements satisfactorily. The challenges in providing suitable resources are to analyze the user service pattern, bandwidth and buffer availability, nature of applications used, and Quality of Service (QoS requirements for the heterogeneous users. Therefore, it is necessary to provide suitable techniques to handle these challenges. In this paper, we propose a framework for peer-to-peer- (P2P- based VoD service in order to provide effective video streaming. It consists of four functional modules, namely, Quality Preserving Multivariate Video Model (QPMVM for efficient server management, tracker for efficient peer management, heuristic-based content distribution, and light weight incentivized sharing mechanism. The first two of these modules are confined to a single entity of the framework while the other two are distributed across entities. Experimental results show that the proposed framework avoids overloading the server, increases the number of clients served, and does not compromise on QoS, irrespective of the fact that the expected framework is slightly reduced.

Non-Cooperative Facial Recognition Video Dataset Collection Plan

Energy Technology Data Exchange (ETDEWEB)

Kimura, Marcia L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Erikson, Rebecca L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lombardo, Nicholas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2013-08-31

The Pacific Northwest National Laboratory (PNNL) will produce a non-cooperative (i.e. not posing for the camera) facial recognition video data set for research purposes to evaluate and enhance facial recognition systems technology. The aggregate data set consists of 1) videos capturing PNNL role players and public volunteers in three key operational settings, 2) photographs of the role players for enrolling in an evaluation database, and 3) ground truth data that documents when the role player is within various camera fields of view. PNNL will deliver the aggregate data set to DHS who may then choose to make it available to other government agencies interested in evaluating and enhancing facial recognition systems. The three operational settings that will be the focus of the video collection effort include: 1) unidirectional crowd flow 2) bi-directional crowd flow, and 3) linear and/or serpentine queues.

Video profile monitor diagnostic system for GTA

International Nuclear Information System (INIS)

Sandoval, D.P.; Garcia, R.C.; Gilpatrick, J.D.; Johnson, K.F.; Shinas, M.A.; Wright, R.; Yuan, V.; Zander, M.E.

1992-01-01

This paper describes a video diagnostic system used to measure the beam profile and position of the Ground Test Accelerator 2.5-MeV H - ion beam as it exits the intermediate matching section. Inelastic collisions between H-ions and residual nitrogen to fluoresce. The resulting light is captured through transport optics by an intensified CCD camera and is digitized. Real-time beam-profile images are displayed and stored for detailed analysis. Analyzed data showing resolutions for both position and profile measurements will also be presented

Efficient fluorescence energy transfer system between CdTe-doped silica nanoparticles and gold nanoparticles for turn-on fluorescence detection of melamine.

Science.gov (United States)

Gao, Feng; Ye, Qingqing; Cui, Peng; Zhang, Lu

2012-05-09

We here report an efficient and enhanced fluorescence energy transfer system between confined quantum dots (QDs) by entrapping CdTe into the mesoporous silica shell (CdTe@SiO₂) as donors and gold nanoparticles (AuNPs) as acceptors. At pH 6.50, the CdTe@SiO₂-AuNPs assemblies coalesce to form larger clusters due to charge neutralization, leading to the fluorescence quenching of CdTe@SiO₂ as a result of energy transfer. As compared with the energy transfer system between unconfined CdTe and AuNPs, the maximum fluorescence quenching efficiency of the proposed system is improved by about 27.0%, and the quenching constant, K(sv), is increased by about 2.4-fold. The enhanced quenching effect largely turns off the fluorescence of CdTe@SiO₂ and provides an optimal "off-state" for sensitive "turn-on" assay. In the present study, upon addition of melamine, the weak fluorescence system of CdTe@SiO₂-AuNPs is enhanced due to the strong interactions between the amino group of melamine and the gold nanoparticles via covalent bond, leading to the release of AuNPs from the surfaces of CdTe@SiO₂; thus, its fluorescence is restored. A "turn-on" fluorimetric method for the detection of melamine is proposed based on the restored fluorescence of the system. Under the optimal conditions, the fluorescence enhanced efficiency shows a linear function against the melamine concentrations ranging from 7.5 × 10⁻⁹ to 3.5 × 10⁻⁷ M (i.e., 1.0-44 ppb). The analytical sensitivity is improved by about 50%, and the detection limit is decreased by 5.0-fold, as compared with the analytical results using the CdTe-AuNPs system. Moreover, the proposed method was successfully applied to the determination of melamine in real samples with excellent recoveries in the range from 97.4 to 104.1%. Such a fluorescence energy transfer system between confined QDs and AuNPs may pave a new way for designing chemo/biosensing.

Processing Decoded Video for LCD-LED Backlight Display

DEFF Research Database (Denmark)

Nadernejad, Ehsan

The quality of digital images and video signal on visual media such as TV screens and LCD displays is affected by two main factors; the display technology and compression standards. Accurate knowledge about the characteristics of display and the video signal can be utilized to develop advanced...... on local LED-LCD backlight. Second, removing the digital video codec artifacts such as blocking and ringing artifacts by post-processing algorithms. A novel algorithm based on image features with optimal balance between visual quality and power consumption was developed. In addition, to remove flickering...... algorithms for signal (image or video) enhancement. One particular application of such algorithms is the case of LCDs with dynamic local backlight. The thesis addressed two main problems; first, designing algorithms that improve the visual quality of perceived image and video and reduce power consumption...

Hybrid compression of video with graphics in DTV communication systems

OpenAIRE

Schaar, van der, M.; With, de, P.H.N.

2000-01-01

Advanced broadcast manipulation of TV sequences and enhanced user interfaces for TV systems have resulted in an increased amount of pre- and post-editing of video sequences, where graphical information is inserted. However, in the current broadcasting chain, there are no provisions for enabling an efficient transmission/storage of these mixed video and graphics signals and, at this emerging stage of DTV systems, introducing new standards is not desired. Nevertheless, in the professional video...

Expression and characterization of insulin growth factor-I-enhanced green fluorescent protein fused protein as a tracer for immunoassay

Energy Technology Data Exchange (ETDEWEB)

Shi Ruina [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Huang Yong [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Wang Dan [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Zhao Meiping [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Li Yuanzong [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)]. E-mail: yzli@pku.edu.cn

2006-09-25

The insulin-like growth factor-I (IGF-I) is an important polypeptide hormone under investigation for body metabolism study and for doping detection. Here, we describe for the first time the expression of a recombinant fusion protein of IGF-I and the enhanced green fluorescent protein (EGFP). The genetic fusion approach enables preparation of conjugates with 1:1 stoichiometry and homogeneous structure. The fused protein (EGFP-IGF-I) was expressed as a soluble protein in cytoplasm of Escherichia coli and its fluorescence and immunoreaction properties were thoroughly characterized. Finally, we demonstrated the utility of the EGFP-IGF-I fusion protein for the fluorescence immunoassay of IGF-1. The linear range of the assay is 1.6 x 10{sup -8} to 2.0 x 10{sup -6} M with a detection limit of 1.6 x 10{sup -8} M. To our knowledge, this is the first time that EGFP has been used as a quantitative label in a fusion protein to develop a quantitative assay for IGF-I. Furthermore, the use of genetically engineered fusion proteins, which combine peptide hormones with fluorescent protein, can lead to a new labeling approach to a number of bioanalytical applications.

Expression and characterization of insulin growth factor-I-enhanced green fluorescent protein fused protein as a tracer for immunoassay

International Nuclear Information System (INIS)

Shi Ruina; Huang Yong; Wang Dan; Zhao Meiping; Li Yuanzong

2006-01-01

The insulin-like growth factor-I (IGF-I) is an important polypeptide hormone under investigation for body metabolism study and for doping detection. Here, we describe for the first time the expression of a recombinant fusion protein of IGF-I and the enhanced green fluorescent protein (EGFP). The genetic fusion approach enables preparation of conjugates with 1:1 stoichiometry and homogeneous structure. The fused protein (EGFP-IGF-I) was expressed as a soluble protein in cytoplasm of Escherichia coli and its fluorescence and immunoreaction properties were thoroughly characterized. Finally, we demonstrated the utility of the EGFP-IGF-I fusion protein for the fluorescence immunoassay of IGF-1. The linear range of the assay is 1.6 x 10 -8 to 2.0 x 10 -6 M with a detection limit of 1.6 x 10 -8 M. To our knowledge, this is the first time that EGFP has been used as a quantitative label in a fusion protein to develop a quantitative assay for IGF-I. Furthermore, the use of genetically engineered fusion proteins, which combine peptide hormones with fluorescent protein, can lead to a new labeling approach to a number of bioanalytical applications

Enhanced 1.32 μm fluorescence and broadband amplifying for O-band optical amplifier in Nd3+-doped tellurite glass

Science.gov (United States)

Zhou, Zi-zhong; Zhou, Ming-han; Su, Xiu-e.; Cheng, Pan; Zhou, Ya-xun

2017-01-01

WO3 oxides with relatively high phonon energy and different concentrations were introduced into the Nd3+-doped tellurite-based glasses of TeO2-ZnO-Na2O to improve the 1.32 μm band fluorescence emission. The absorption spectra, Raman spectra, 1.32 μm band fluorescence spectra and differential scanning calorimeter (DSC) curves were measured, together with the Judd-Ofelt intensity parameters, stimulated emission and gain parameters were calculated to evaluate the effects of WO3 amount on the glass structure and spectroscopic properties of 1.32 μm band fluorescence. It is shown that the introduction of an appropriate amount of WO3 oxide can effectively improve the 1.32 μm band fluorescence intensity through the enhanced multi-phonon relaxation (MPR) processes between the excited levels of Nd3+. The results indicate that the prepared Nd3+-doped tellurite glass with an appropriate amount of WO3 oxide is a potential gain medium applied for the O-band broad and high-gain fiber amplifier.

5-ALA/PpIX fluorescence detection of gastrointestinal neoplasia

Science.gov (United States)

Borisova, Ekaterina G.; Vladimirov, Borislav; Terziev, Ivan; Ivanova, Radina; Avramov, Latchezar

2009-07-01

In the recent study delta-ALA/PpIX is used as fluorescent marker for dysplasia and tumor detection in esophagus, stomach and colon. ALA is administered per os six to eight (depending on the lesion location) hours before measurements at dose 20mg/kg weight. High-power light-emitting diode at 405 nm is used as an excitation source. Special opto-mechanical device is built for the LED to use the light guide of standard video-endoscopic system. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. The fluorescence detected from tumor sites has very complex spectral origins. It consists of autofluorescence, fluorescence from exogenous fluorophores and re-absorption from the chromophores accumulated in the tissue investigated. 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 re-absorption of oxy-hemoglobin in this spectral area. Endogenous and exogenous fluorescence spectra are used to develop simple but effective algorithm, based on dimensionless ratio of the signals at 560 and 635 nm, for differentiation of normal/abnormal gastrointestinal tissues. Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

A set of enhanced green fluorescent protein concatemers for quantitative determination of nuclear localization signal strength.

Science.gov (United States)

Böhm, Jennifer; Thavaraja, Ramya; Giehler, Susanne; Nalaskowski, Marcus M

2017-09-15

Regulated transport of proteins between nucleus and cytoplasm is an important process in the eukaryotic cell. In most cases, active nucleo-cytoplasmic protein transport is mediated by nuclear localization signal (NLS) and/or nuclear export signal (NES) motifs. In this study, we developed a set of vectors expressing enhanced GFP (EGFP) concatemers ranging from 2 to 12 subunits (2xEGFP to 12xEGFP) for analysis of NLS strength. As shown by in gel GFP fluorescence analysis and αGFP Western blotting, EGFP concatemers are expressed as fluorescent full-length proteins in eukaryotic cells. As expected, nuclear localization of concatemeric EGFPs decreases with increasing molecular weight. By oligonucleotide ligation this set of EGFP concatemers can be easily fused to NLS motifs. After determination of intracellular localization of EGFP concatemers alone and fused to different NLS motifs we calculated the size of a hypothetic EGFP concatemer showing a defined distribution of EGFP fluorescence between nucleus and cytoplasm (n/c ratio = 2). Clear differences of the size of the hypothetic EGFP concatemer depending on the fused NLS motif were observed. Therefore, we propose to use the size of this hypothetic concatemer as quantitative indicator for comparing strength of different NLS motifs. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and characterization of enhanced green fluorescent protein and luciferase expressing cell line for non-destructive evaluation of tissue engineering constructs.

NARCIS (Netherlands)

Blum, J.S.; Temenoff, J.S.; Park, H.; Jansen, J.A.; Mikos, A.G.; Barry, M.A.

2004-01-01

This study investigates the utility of genetically modified cells developed for the qualitative and quantitative non-destructive evaluation of cells on biomaterials. The Fisher rat fibroblastic cell line has been genetically modified to stably express the reporter genes enhanced green fluorescence

Kinetics of bacterial fluorescence staining with 3,3'-diethylthiacyanine.

Science.gov (United States)

Thomas, Marlon S; Nuñez, Vicente; Upadhyayula, Srigokul; Zielins, Elizabeth R; Bao, Duoduo; Vasquez, Jacob M; Bahmani, Baharak; Vullev, Valentine I

2010-06-15

For more than a century, colorimetric and fluorescence staining have been the foundation of a broad range of key bioanalytical techniques. The dynamics of such staining processes, however, still remains largely unexplored. We investigated the kinetics of fluorescence staining of two gram-negative and two gram-positive species with 3,3'-diethylthiacyanine (THIA) iodide. An increase in the THIA fluorescence quantum yield, induced by the bacterial dye uptake, was the principal reason for the observed emission enhancement. The fluorescence quantum yield of THIA depended on the media viscosity and not on the media polarity, which suggested that the microenvironment of the dye molecules taken up by the cells was restrictive. The kinetics of fluorescence staining did not manifest a statistically significant dependence neither on the dye concentration, nor on the cell count. In the presence of surfactant additives, however, the fluorescence-enhancement kinetic patterns manifested species specificity with statistically significant discernibility.

Application of robust face recognition in video surveillance systems

Science.gov (United States)

Zhang, De-xin; An, Peng; Zhang, Hao-xiang

2018-03-01

In this paper, we propose a video searching system that utilizes face recognition as searching indexing feature. As the applications of video cameras have great increase in recent years, face recognition makes a perfect fit for searching targeted individuals within the vast amount of video data. However, the performance of such searching depends on the quality of face images recorded in the video signals. Since the surveillance video cameras record videos without fixed postures for the object, face occlusion is very common in everyday video. The proposed system builds a model for occluded faces using fuzzy principal component analysis (FPCA), and reconstructs the human faces with the available information. Experimental results show that the system has very high efficiency in processing the real life videos, and it is very robust to various kinds of face occlusions. Hence it can relieve people reviewers from the front of the monitors and greatly enhances the efficiency as well. The proposed system has been installed and applied in various environments and has already demonstrated its power by helping solving real cases.

Fluorescence spectroscopy for medical and environmental diagnostics

International Nuclear Information System (INIS)

Johansson, Jonas.

1993-09-01

Fluorescence spectroscopy can be used for diagnostics in medical and environmental applications. The many aspects of fluorescence emission are utilized to enhance the accuracy of the diagnosis. A fluorescence detection system, based on nitrogen laser or dye laser excitation and optical multichannel detection, was constructed, and fluorescence spectra from human malignant tumours of various origins, were recorded. Tumour demarcation was observed using exogenous chromophores, as well as the endogenous tissue fluorescence. In particular, δ-amino levulinic acid was found to provide very good tumour demarcation. A multi-colour imaging system capable of simultaneous recording of four fluorescence images at selected wavelengths, was developed. Examples of processed images, based on the four sub-images, are shown for malignant tumours. In addition, data from photodynamic treatment of human malignant tumours are presented. Autofluorescence spectra from excised pieces of human atherosclerotic aorta and atherosclerotic coronary segment were found to be different from those of non-diseased vessels. Furthermore, fluorescence decay curves from atherosclerotic samples were found to differ from those of non-diseased samples. It is concluded that both spectral and temporal information should be utilized to enhance the demarcation. Methods for obtaining fluorescence data free from interference from blood, with applications to in vivo laser angioplasty of atherosclerosis, are discussed. The optical multichannel system and the multi-colour imaging system were integrated with a remote sensing system, originally used for environmental measurements, to obtain fluorescence spectra as well as fluorescence images of plants at a distance of up to 100 m. The fluorescence data from plants subject to environmental stress or senescent plants were found to differ from those obtained from healthy vegetation. 359 refs

Storage, access, and retrieval of endoscopic and laparoscopic video

Science.gov (United States)

Bellaire, Gunter; Steines, Daniel; Graschew, Georgi; Thiel, Andreas; Bernarding, Johannes; Tolxdorff, Thomas; Schlag, Peter M.

1999-05-01

The system presented here enhances documentation and data- secured, second-opinion facilities by integrating video into DICOM3.0. Digital stereoscopic video sequences (DSVS) are especially in demand for surgery (laparoscopy, microsurgery, surgical microscopy, second opinion, virtual reality). Therefore DSVS are also integrated into the DICOM video concept. We present an implementation for a medical video server extended by a DICOM interface. Security mechanisms conforming with DICOM are integrated to enable secure internet access. Digital (stereoscopic) video sequences relevant for surgery should be examined regarding the clip length necessary for diagnosis and documentation and the clip size manageable with today's hardware. Methods for DSVS compression are described, implemented, and tested. Image sources relevant for this paper include, among others, a stereoscopic laparoscope and a monoscopic endoscope. Additionally, an approach is presented to analyze the motion of the endoscopic camera for future automatic video- cutting.

Video games as a tool to train visual skills

Science.gov (United States)

Achtman, R.L.; Green, C.S.; Bavelier, D.

2010-01-01

Purpose Adult brain plasticity, although possible, is often difficult to elicit. Training regimens in adults can produce specific improvements on the trained task without leading to general enhancements that would improve quality of life. This paper considers the case of playing action video games as a way to induce widespread enhancement in vision. Conclusions We review the range of visual skills altered by action video game playing as well as the game components important in promoting visual plasticity. Further, we discuss what these results might mean in terms of rehabilitation for different patient populations. PMID:18997318

Video games and rehabilitation: using design principles to enhance engagement in physical therapy.

Science.gov (United States)

Lohse, Keith; Shirzad, Navid; Verster, Alida; Hodges, Nicola; Van der Loos, H F Machiel

2013-12-01

Patient nonadherence with therapy is a major barrier to rehabilitation. Recovery is often limited and requires prolonged, intensive rehabilitation that is time-consuming, expensive, and difficult. We review evidence for the potential use of video games in rehabilitation with respect to the behavioral, physiological, and motivational effects of gameplay. In this Special Interest article, we offer a method to evaluate effects of video game play on motor learning and their potential to increase patient engagement with therapy, particularly commercial games that can be interfaced with adapted control systems. We take the novel approach of integrating research across game design, motor learning, neurophysiology changes, and rehabilitation science to provide criteria by which therapists can assist patients in choosing games appropriate for rehabilitation. Research suggests that video games are beneficial for cognitive and motor skill learning in both rehabilitation science and experimental studies with healthy subjects. Physiological data suggest that gameplay can induce neuroplastic reorganization that leads to long-term retention and transfer of skill; however, more clinical research in this area is needed. There is interdisciplinary evidence suggesting that key factors in game design, including choice, reward, and goals, lead to increased motivation and engagement. We maintain that video game play could be an effective supplement to traditional therapy. Motion controllers can be used to practice rehabilitation-relevant movements, and well-designed game mechanics can augment patient engagement and motivation in rehabilitation. We recommend future research and development exploring rehabilitation-relevant motions to control games and increase time in therapy through gameplay.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A61) for more insights from the authors.

Rate-distortion optimization for compressive video sampling

Science.gov (United States)

Liu, Ying; Vijayanagar, Krishna R.; Kim, Joohee

2014-05-01

The recently introduced compressed sensing (CS) framework enables low complexity video acquisition via sub- Nyquist rate sampling. In practice, the resulting CS samples are quantized and indexed by finitely many bits (bit-depth) for transmission. In applications where the bit-budget for video transmission is constrained, rate- distortion optimization (RDO) is essential for quality video reconstruction. In this work, we develop a double-level RDO scheme for compressive video sampling, where frame-level RDO is performed by adaptively allocating the fixed bit-budget per frame to each video block based on block-sparsity, and block-level RDO is performed by modelling the block reconstruction peak-signal-to-noise ratio (PSNR) as a quadratic function of quantization bit-depth. The optimal bit-depth and the number of CS samples are then obtained by setting the first derivative of the function to zero. In the experimental studies the model parameters are initialized with a small set of training data, which are then updated with local information in the model testing stage. Simulation results presented herein show that the proposed double-level RDO significantly enhances the reconstruction quality for a bit-budget constrained CS video transmission system.

Fluorescence intensity dependence on the propagation plane inclination

International Nuclear Information System (INIS)

Fernandez, J.E.; Rubio, Marcelo; Sanchez, H. J.

1987-01-01

An experimental confirmation of the fluorescence intensity behaviour with the inclination of the propagation plane (α angle) was carried out. A special angular sample-holder was developed and set up on our X-ray spectrometer. This sample-holder allows different positions of irradiation of the sample modifying the α angle until the maximum angle (α Μ ) is reached in the limit situation. In this work, this maximum angle was 86 deg and the incidence and take off angles were both 45 deg. The sample-holder and the collimation system were carefully lined up. The fluorescent spectra of three National Bureau of Standards (NBS) standard samples were taken for sixteen different α angle positions. The theoretical scheme for both enhanced fluorescent lines and nonenhanced fluorescent lines was confirmed, i.e. the invariance of the primary intensity with the α angle and the decline of the enhanced fluorescence intensities under the same conditions. This experimental confirmation agrees with theoretical prediction: the vanishing of the secondary fluorescence in the extreme case α = π/2. (Author) [es

Using web-based video to enhance physical examination skills in medical students.

Science.gov (United States)

Orientale, Eugene; Kosowicz, Lynn; Alerte, Anton; Pfeiffer, Carol; Harrington, Karen; Palley, Jane; Brown, Stacey; Sapieha-Yanchak, Teresa

2008-01-01

Physical examination (PE) skills among U.S. medical students have been shown to be deficient. This study examines the effect of a Web-based physical examination curriculum on first-year medical student PE skills. Web-based video clips, consisting of instruction in 77 elements of the physical examination, were created using Microsoft Windows Moviemaker software. Medical students' PE skills were evaluated by standardized patients before and after implementation of the Internet-based video. Following implementation of this curriculum, there was a higher level of competency (from 87% in 2002-2003 to 91% in 2004-2005), and poor performances on standardized patient PE exams substantially diminished (from a 14%-22%failure rate in 2002-2003, to 4% in 2004-2005. A significant improvement in first-year medical student performance on the adult PE occurred after implementing Web-based instructional video.

Performance Enhancement of Pharmacokinetic Diffuse Fluorescence Tomography by Use of Adaptive Extended Kalman Filtering.

Science.gov (United States)

Wang, Xin; Wu, Linhui; Yi, Xi; Zhang, Yanqi; Zhang, Limin; Zhao, Huijuan; Gao, Feng

2015-01-01

Due to both the physiological and morphological differences in the vascularization between healthy and diseased tissues, pharmacokinetic diffuse fluorescence tomography (DFT) can provide contrast-enhanced and comprehensive information for tumor diagnosis and staging. In this regime, the extended Kalman filtering (EKF) based method shows numerous advantages including accurate modeling, online estimation of multiparameters, and universal applicability to any optical fluorophore. Nevertheless the performance of the conventional EKF highly hinges on the exact and inaccessible prior knowledge about the initial values. To address the above issues, an adaptive-EKF scheme is proposed based on a two-compartmental model for the enhancement, which utilizes a variable forgetting-factor to compensate the inaccuracy of the initial states and emphasize the effect of the current data. It is demonstrated using two-dimensional simulative investigations on a circular domain that the proposed adaptive-EKF can obtain preferable estimation of the pharmacokinetic-rates to the conventional-EKF and the enhanced-EKF in terms of quantitativeness, noise robustness, and initialization independence. Further three-dimensional numerical experiments on a digital mouse model validate the efficacy of the method as applied in realistic biological systems.

Using Video Game-Based Instruction in an EFL Program: Understanding the Power of Video Games in Education

Directory of Open Access Journals (Sweden)

Héctor Alejandro Galvis Guerrero

2011-09-01

Full Text Available This small-scale action-research study examines the perceptions of four students in a military academy in Colombia undergoing the processof using a mainstream video game in their EFL classes instead of classic forms of instruction. The video game used served to approach EFL by means of language exploratory activities designed according to the context present in the video game and the course linguistic objectives. This study was conducted on the grounds that computer technology offers the possibility of enhancing EFL instruction by means of simulating and augmenting the target language context. The researcher’s belief is that video games offer a learning environment closely related to students’ experiences and preferences. Results from this study suggest that students were more entertained and attentive and demonstrated more engagement and disposition towards their English classes. Students also learned about matters related to the target language and culture, and were not only circumscribed to linguistic ones. Similarly, results from this study shed some light on the importance of offering access to technology to students before they advance to higher education that support video-gaming practices in the classroom.

Hybrid nanostructures of well-organized arrays of colloidal quantum dots and a self-assembled monolayer of gold nanoparticles for enhanced fluorescence

Science.gov (United States)

Liu, Xiaoying; McBride, Sean P.; Jaeger, Heinrich M.; Nealey, Paul F.

2016-07-01

Hybrid nanomaterials comprised of well-organized arrays of colloidal semiconductor quantum dots (QDs) in close proximity to metal nanoparticles (NPs) represent an appealing system for high-performance, spectrum-tunable photon sources with controlled photoluminescence. Experimental realization of such materials requires well-defined QD arrays and precisely controlled QD-metal interspacing. This long-standing challenge is tackled through a strategy that synergistically combines lateral confinement and vertical stacking. Lithographically generated nanoscale patterns with tailored surface chemistry confine the QDs into well-organized arrays with high selectivity through chemical pattern directed assembly, while subsequent coating with a monolayer of close-packed Au NPs introduces the plasmonic component for fluorescence enhancement. The results show uniform fluorescence emission in large-area ordered arrays for the fabricated QD structures and demonstrate five-fold fluorescence amplification for red, yellow, and green QDs in the presence of the Au NP monolayer. Encapsulation of QDs with a silica shell is shown to extend the design space for reliable QD/metal coupling with stronger enhancement of 11 times through the tuning of QD-metal spatial separation. This approach provides new opportunities for designing hybrid nanomaterials with tailored array structures and multiple functionalities for applications such as multiplexed optical coding, color display, and quantum transduction.

Fluorescent genetic barcoding in mammalian cells for enhanced multiplexing capabilities in flow cytometry.

Science.gov (United States)

Smurthwaite, Cameron A; Hilton, Brett J; O'Hanlon, Ryan; Stolp, Zachary D; Hancock, Bryan M; Abbadessa, Darin; Stotland, Aleksandr; Sklar, Larry A; Wolkowicz, Roland

2014-01-01

The discovery of the green fluorescent protein from Aequorea victoria has revolutionized the field of cell and molecular biology. Since its discovery a growing panel of fluorescent proteins, fluorophores and fluorescent-coupled staining methodologies, have expanded the analytical capabilities of flow cytometry. Here, we exploit the power of genetic engineering to barcode individual cells with genes encoding fluorescent proteins. For genetic engineering, we utilize retroviral technology, which allows for the expression of ectopic genetic information in a stable manner in mammalian cells. We have genetically barcoded both adherent and nonadherent cells with different fluorescent proteins. Multiplexing power was increased by combining both the number of distinct fluorescent proteins, and the fluorescence intensity in each channel. Moreover, retroviral expression has proven to be stable for at least a 6-month period, which is critical for applications such as biological screens. We have shown the applicability of fluorescent barcoded multiplexing to cell-based assays that rely themselves on genetic barcoding, or on classical staining protocols. Fluorescent genetic barcoding gives the cell an inherited characteristic that distinguishes it from its counterpart. Once cell lines are developed, no further manipulation or staining is required, decreasing time, nonspecific background associated with staining protocols, and cost. The increasing number of discovered and/or engineered fluorescent proteins with unique absorbance/emission spectra, combined with the growing number of detection devices and lasers, increases multiplexing versatility, making fluorescent genetic barcoding a powerful tool for flow cytometry-based analysis. © 2013 International Society for Advancement of Cytometry.

Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion

International Nuclear Information System (INIS)

Liu Zhengqing; Liu Shaopu; Yin Pengfei; He Youqiu

2012-01-01

Graphical abstract: Glyphosate (Glyp) had been used to modify the surface of CdTe/CdS QDs, resulting in the enhancement of fluorescence intensity. The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu 2+ based on the fluorescence quenching. Highlights: ► Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. ► The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. ► A new fluorescent sensor for copper ion was developed based on the prepared QDs. ► The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu 2+ determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core–shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu 2+ between 2.4 × 10 −2 μg mL −1 and 28 μg mL −1 , with a detection limit of 1.3 × 10 −3 μg mL −1 (3δ). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu 2+ . The fluorescent probe was successfully used for the determination of Cu 2+ in environmental samples. The mechanism of reaction was also discussed.

Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

Science.gov (United States)

Yilmaz, Hasan

2016-03-01

Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

Staff acceptance of video monitoring for coordination: a video system to support perioperative situation awareness.

Science.gov (United States)

Kim, Young Ju; Xiao, Yan; Hu, Peter; Dutton, Richard

2009-08-01

To understand staff acceptance of a remote video monitoring system for operating room (OR) coordination. Improved real-time remote visual access to OR may enhance situational awareness but also raises privacy concerns for patients and staff. Survey. A system was implemented in a six-room surgical suite to display OR monitoring video at an access restricted control desk area. Image quality was manipulated to improve staff acceptance. Two months after installation, interviews and a survey were conducted on staff acceptance of video monitoring. About half of all OR personnel responded (n = 63). Overall levels of concerns were low, with 53% rated no concerns and 42% little concern. Top two reported uses of the video were to see if cases are finished and to see if a room is ready. Viewing the video monitoring system as useful did not reduce levels of concern. Staff in supervisory positions perceived less concern about the system's impact on privacy than did those supervised (p < 0.03). Concerns for patient privacy correlated with concerns for staff privacy and performance monitoring. Technical means such as manipulating image quality helped staff acceptance. Manipulation of image quality resulted overall acceptance of monitoring video, with residual levels of concerns. OR nurses may express staff privacy concern in the form of concerns over patient privacy. This study provided suggestions for technological and implementation strategies of video monitoring for coordination use in OR. Deployment of communication technology and integration of clinical information will likely raise concerns over staff privacy and performance monitoring. The potential gain of increased information access may be offset by negative impact of a sense of loss of autonomy.

Highly fluorescent benzofuran derivatives of the GFP chromophore

DEFF Research Database (Denmark)

Christensen, Mikkel Andreas; Jennum, Karsten Stein; Abrahamsen, Peter Bæch

2012-01-01

Intramolecular cyclization reactions of Green Fluorescent Protein chromophores (GFPc) containing an arylethynyl ortho-substituent at the phenol ring provide new aryl-substituted benzofuran derivatives of the GFPc. Some of these heteroaromatic compounds exhibit significantly enhanced fluorescence...

Games people play: How video games improve probabilistic learning.

Science.gov (United States)

Schenk, Sabrina; Lech, Robert K; Suchan, Boris

2017-09-29

Recent research suggests that video game playing is associated with many cognitive benefits. However, little is known about the neural mechanisms mediating such effects, especially with regard to probabilistic categorization learning, which is a widely unexplored area in gaming research. Therefore, the present study aimed to investigate the neural correlates of probabilistic classification learning in video gamers in comparison to non-gamers. Subjects were scanned in a 3T magnetic resonance imaging (MRI) scanner while performing a modified version of the weather prediction task. Behavioral data yielded evidence for better categorization performance of video gamers, particularly under conditions characterized by stronger uncertainty. Furthermore, a post-experimental questionnaire showed that video gamers had acquired higher declarative knowledge about the card combinations and the related weather outcomes. Functional imaging data revealed for video gamers stronger activation clusters in the hippocampus, the precuneus, the cingulate gyrus and the middle temporal gyrus as well as in occipital visual areas and in areas related to attentional processes. All these areas are connected with each other and represent critical nodes for semantic memory, visual imagery and cognitive control. Apart from this, and in line with previous studies, both groups showed activation in brain areas that are related to attention and executive functions as well as in the basal ganglia and in memory-associated regions of the medial temporal lobe. These results suggest that playing video games might enhance the usage of declarative knowledge as well as hippocampal involvement and enhances overall learning performance during probabilistic learning. In contrast to non-gamers, video gamers showed better categorization performance, independently of the uncertainty of the condition. Copyright © 2017 Elsevier B.V. All rights reserved.

Commercial Video Programs: A Component to Enhance Language Skills.

Science.gov (United States)

Linares, H. A.

After the passage of a resolution by the South Dakota Board of Regents to place greater emphasis on the study of foreign language, Northern State College introduced commercial video programs in Spanish for classroom use. After installing a parabolic antenna and the other necessary equipment, the department selected and edited a series of programs,…

VideoSET: Video Summary Evaluation through Text

OpenAIRE

Yeung, Serena; Fathi, Alireza; Fei-Fei, Li

2014-01-01

In this paper we present VideoSET, a method for Video Summary Evaluation through Text that can evaluate how well a video summary is able to retain the semantic information contained in its original video. We observe that semantics is most easily expressed in words, and develop a text-based approach for the evaluation. Given a video summary, a text representation of the video summary is first generated, and an NLP-based metric is then used to measure its semantic distance to ground-truth text ...

Multi-site and multi-depth in vivo cancer localization enhancement after auto-fluorescence removal

International Nuclear Information System (INIS)

Montcuquet, A.S.; Herve, L.; Navarro, F.; Dinten, J.M.; Mars, J.I.

2011-01-01

Fluorescence imaging in diffusive media locates tumors tagged by injected fluorescent markers in NIR wavelengths. For deep embedded markers, natural auto-fluorescence of tissues comes to be a limiting factor to tumor detection and accurate FDOT reconstructions. A spectroscopic approach coupled with Non-negative Matrix Factorization source separation method is explored to discriminate fluorescence sources according to their fluorescence spectra and remove unwanted auto-fluorescence. We successfully removed auto-fluorescence from acquisitions on living mice with a single subcutaneous tumor or two capillary tubes inserted at different depths. (authors)

Enhancing Students' Speaking Skills through "Kunci Inggris" Videos in Islamic Junior High School

Science.gov (United States)

Erlangga, Rifqi Aulia

2016-01-01

Personal ability of a teacher when integrated with good learning material will make his students get more involved and absorb teaching material better hence improving their foreign language. There are many materials may be used to teach, one of them is videos. The video is expected to trigger students' enthusiasm and improve their motivation. Even…

Intraoperative efficiency of fluorescence imaging by Visually Enhanced Lesion Scope (VELscope) in patients with bisphosphonate related osteonecrosis of the jaw (BRONJ).

Science.gov (United States)

Assaf, Alexandre T; Zrnc, Tomislav A; Riecke, Björn; Wikner, Johannes; Zustin, Jozef; Friedrich, Reinhard E; Heiland, Max; Smeets, Ralf; Gröbe, Alexander

2014-07-01

The purpose of this study was to determine the potential of tissue fluorescence imaging by using Visually Enhanced Lesion Scope (VELscope) for the detection of osteonecrosis of the jaw induced by bisphosphonates (BRONJ). We investigated 20 patients (11 females and 9 males; mean age 74 years, standard deviation ± 6.4 years), over a period of 18 month with the diagnosis of BRONJ in this prospective cohort study. All patients received doxycycline as a fluorescending marker for osseous structures. VELscope has been used intraoperatively using the loss of fluorescence to detect presence of osteonecrosis. Osseous biopsies were taken to confirm definite histopathological diagnosis of BRONJ in each case. Diagnosis of BRONJ was confirmed for every patient. In all patients except one, VELscope was sufficient to differentiate between healthy and necrotic bone by visual fluorescence retention (VFR) and visual fluorescence loss (VFL). 19 cases out of a total of 20 showed no signs of recurrence of BRONJ during follow-up (mean 12 months, range 4-18 months). VELscope examination is a suitable tool to visualize necrotic areas of the bone in patients with bisphosphonate related osteonecrosis of the jaw. Loss of fluorescence in necrotic bone areas is useful intraoperatively as a tool for fluorescence-guided bone resection with relevant clinical interpretation. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Fluorescent properties of novel dendrimer dyes based on thiazole orange

International Nuclear Information System (INIS)

Fei Xuening; Gu Yingchun; Lan Yunquan; Shi Bin

2011-01-01

In this paper, polyamidoamine (PAMAM) dendrimers with active amino group of some generations (G=0.5-2) were prepared from commercial aminoacetaldehyde diethyl acetal by the divergent method. After that, thiazole orange (TO) with -COOH was incorporated with dendrimers of G=1 and 2 to afford novel dendrimer-TO dyes. The fluorescent properties studies showed that the fluorescent intensity of the same concentration of dendrimer-TO (G=2) was higher than that of the dendrimer-TO (G=1), and both of them were much stronger than free TO with -COOH. There was a fluorescent enhancement of the dendrimer dyes compared with free dye. The dendrimer dyes were of well-defined chemical structure,with little aggregation and self-quenching as well as good fluorescence properties of good stability, high intensity and sensitivity, which could be used in labeling cancer cells and further in diagnosis and detection of early-stage tumors. - Highlights: → A kind of dendrimer probe based on TO was designed and synthesized. → Dendrimers showed an obvious fluorescence enhancement compared to free dye. → Dendrimers labeled with BSA also showed fluorescence enhancement. → Dendrimers may be used in diagnosis and detection of early-stage tumors.

Predicting the "usefulness" of 5-ALA-derived tumor fluorescence for fluorescence-guided resections in pediatric brain tumors

DEFF Research Database (Denmark)

Stummer, Walter; Rodrigues, Floriano; Schucht, Philippe

2014-01-01

fluorescence was "useful", i.e., leading to changes in surgical strategy or identification of residual tumor. Recursive partitioning analysis (RPA) was used for defining cohorts with high or low likelihoods for useful fluorescence. RESULTS: Data on 78 patients ..., 25 %) and pilocytic astrocytomas (two of 13; 15 %). RPA of pre-operative factors showed tumors with supratentorial location, strong contrast enhancement and first operation to have a likelihood of useful fluorescence of 64.3 %, as opposed to infratentorial tumors with first surgery (23...

Neural Basis of Enhanced Executive Function in Older Video Game Players: An fMRI Study.

Science.gov (United States)

Wang, Ping; Zhu, Xing-Ting; Qi, Zhigang; Huang, Silin; Li, Hui-Jie

2017-01-01

Video games have been found to have positive influences on executive function in older adults; however, the underlying neural basis of the benefits from video games has been unclear. Adopting a task-based functional magnetic resonance imaging (fMRI) study targeted at the flanker task, the present study aims to explore the neural basis of the improved executive function in older adults with video game experiences. Twenty video game players (VGPs) and twenty non-video game players (NVGPs) of 60 years of age or older participated in the present study, and there are no significant differences in age ( t = 0.62, p = 0.536), gender ratio ( t = 1.29, p = 0.206) and years of education ( t = 1.92, p = 0.062) between VGPs and NVGPs. The results show that older VGPs present significantly better behavioral performance than NVGPs. Older VGPs activate greater than NVGPs in brain regions, mainly in frontal-parietal areas, including the right dorsolateral prefrontal cortex, the left supramarginal gyrus, the right angular gyrus, the right precuneus and the left paracentral lobule. The present study reveals that video game experiences may have positive influences on older adults in behavioral performance and the underlying brain activation. These results imply the potential role that video games can play as an effective tool to improve cognitive ability in older adults.

Neural Basis of Enhanced Executive Function in Older Video Game Players: An fMRI Study

Directory of Open Access Journals (Sweden)

Ping Wang

2017-11-01

Full Text Available Video games have been found to have positive influences on executive function in older adults; however, the underlying neural basis of the benefits from video games has been unclear. Adopting a task-based functional magnetic resonance imaging (fMRI study targeted at the flanker task, the present study aims to explore the neural basis of the improved executive function in older adults with video game experiences. Twenty video game players (VGPs and twenty non-video game players (NVGPs of 60 years of age or older participated in the present study, and there are no significant differences in age (t = 0.62, p = 0.536, gender ratio (t = 1.29, p = 0.206 and years of education (t = 1.92, p = 0.062 between VGPs and NVGPs. The results show that older VGPs present significantly better behavioral performance than NVGPs. Older VGPs activate greater than NVGPs in brain regions, mainly in frontal-parietal areas, including the right dorsolateral prefrontal cortex, the left supramarginal gyrus, the right angular gyrus, the right precuneus and the left paracentral lobule. The present study reveals that video game experiences may have positive influences on older adults in behavioral performance and the underlying brain activation. These results imply the potential role that video games can play as an effective tool to improve cognitive ability in older adults.

Confocal fluorescence techniques in industrial application

Science.gov (United States)

Eggeling, Christian; Gall, Karsten; Palo, Kaupo; Kask, Peet; Brand, Leif

2003-06-01

The FCS+plus family of evaluation tools for confocal fluorescence spectroscopy, which was developed during recent years, offers a comprehensive view to a series of fluorescence properties. Originating in fluorescence correlation spectroscopy (FCS) and using similar experimental equipment, a system of signal processing methods such as fluorescence intensity distribution analysis (FIDA) was created to analyze in detail the fluctuation behavior of fluorescent particles within a small area of detection. Giving simultaneous access to molecular parameters like concentration, translational and rotational diffusion, molecular brightness, and multicolor coincidence, this portfolio was enhanced by more traditional techniques of fluorescence lifetime as well as time-resolved anisotropy determination. The cornerstones of the FCS+plus methodology will be shortly described. The inhibition of a phosphatase enzyme activity gives a comprehensive industrial application that demonstrates FCS+plus' versatility and its potential for pharmaceutical drug discovery.

Do Action Video Games Improve Perception and Cognition?

Directory of Open Access Journals (Sweden)

Walter Richard Boot

2011-09-01

Full Text Available Frequent action video game players often outperform non-gamers on measures of perception and cognition, and some studies find that video game practice enhances those abilities. The possibility that video game training transfers broadly to other aspects of cognition is exciting because training on one task rarely improves performance on others. At first glance, the cumulative evidence suggests a strong relationship between gaming experience and other cognitive abilities, but methodological shortcomings call that conclusion into question. We discuss these pitfalls, identify how existing studies succeed or fail in overcoming them, and provide guidelines for more definitive tests of the effects of gaming on cognition.

Enhancing analysis of cells and proteins by fluorescence imaging on silk-based biomaterials: modulating the autofluorescence of silk.

Science.gov (United States)

Neo, Puay Yong; Tan, Daryl Jian-An; Shi, Pujiang; Toh, Siew Lok; Goh, James Cho-Hong

2015-02-01

emission wavelengths compared with the red emission wavelength. This study has showed that the use of SB is a cost and time effective approach to enhance fluorescence-based imaging analyses of cell-seeded silk biomaterials, which otherwise would have been hindered by the unmodulated autofluorescence signals.

Computer-Aided Video Differential Planimetry

Science.gov (United States)

Tobin, Michael; Djoleto, Ben D.

1984-08-01

THE VIDEO DIFFERENTIAL PLANIMETER (VDP)1 is a re-mote sensing instrument that can measure minute changes in the area of any object seen by an optical scanning system. The composite video waveforms obtained by scanning the object against a contrasting back-ground are amplified and shaped to yield a sequence of constant amplitude pulses whose polarity distinguishes the studied area from its background and whose varying widths reflect the dynamics of the viewed object. These pulses are passed through a relatively long time-constant capacitor-resistor circuit and are then fed into an integrator. The net integration voltage resulting from the most recent sequence of object-background time pulses is recorded and the integrator is returned to zero at the end of each video frame. If the object's area remains constant throughout the following frame, the integrator's summation will also remain constant. However, if the object's area varies, the positive and negative time pulses entering the integrator will change, and the integrator's summation will vary proportionately. The addition of a computer interface and a video recorder enhances the versatility and the resolving power of the VDP by permitting the repeated study and analysis of selected portions of the recorded data, thereby uncovering the major sources of the object's dynamics. Among the medical and biological procedures for which COMPUTER-AIDED VIDEO DIFFERENTIAL PLANIMETRY is suitable are Ophthalmoscopy, Endoscopy, Microscopy, Plethysmography, etc. A recent research study in Ophthalmoscopy2 will be cited to suggest a useful application of Video Differential Planimetry.

Novel fluorescence nanobubbles for contrast-enhanced ultrasound imaging in rabbit VX2 hepatocellular carcinoma model

Science.gov (United States)

Yu, Houqiang; Wang, Wei; He, Xiaoling; Zhou, Qibing; Ding, Mingyue

2017-03-01

Ultrasound contrast agents (UCAs) such as SonoVue or Optison have been used widely in clinic for contrast-enhanced vascular imaging. However, microbubbles UCAs display limitations in tumor-targeted imaging due to the large sizes, nanoscaled UCAs has consequently attracted increasing attentions. In this work, we synthesized nanobubbles (NBs) by ultrasonic cavitation method, then a fluorescent marker of Alexa Fluor 680 was conjugated to the shell in order to observe the localization of NBs in tumor tissue. Measurement of fundamental characteristics showed that the NBs had homogeneous distribution of mean diameter of 267.9 +/- 19.2 nm and polydispersity index of 0.410 +/- 0.056. To assess in vivo tumor-selectivity of NBs, we established the rabbits VX2 hepatocellular carcinoma model though surgical implantation method. After the rabbits were intravenous administered of NBs, contrast-enhanced sonograms was observed in the surrounding of VX2 tumor, which showed there are rich capillaries in the tumor periphery. We additionally investigated the toxic of the NBs by hematoxylin-eosin staining. The results indicated that the NBs is a biocompatible non-toxic lipid system. Furthermore, the VX2 tumors and major organs were analyzed using ex vivo fluorescence imaging to confirm the targeted selectivity of NBs, and the results verified that the NBs were capable of targeting VX2 tumor. Confocal laser scanning microscopy examination showed that the NBs can traverse the VX2 tumor capillaries and target to the hepatocellular carcinoma tumor cells. All these results suggested that the newly prepared NBs have a potential application in molecular imaging and tumor-targeting therapy.

Video gaming enhances psychomotor skills but not visuospatial and perceptual abilities in surgical trainees.

Science.gov (United States)

Kennedy, A M; Boyle, E M; Traynor, O; Walsh, T; Hill, A D K

2011-01-01

There is considerable interest in the identification and assessment of underlying aptitudes or innate abilities that could potentially predict excellence in the technical aspects of operating. However, before the assessment of innate abilities is introduced for high-stakes assessment (such as competitive selection into surgical training programs), it is essential to determine that these abilities are stable and unchanging and are not influenced by other factors, such as the use of video games. The aim of this study was to investigate whether experience playing video games will predict psychomotor performance on a laparoscopic simulator or scores on tests of visuospatial and perceptual abilities, and to examine the correlation, if any, between these innate abilities. Institutional ethical approval was obtained. Thirty-eight undergraduate medical students with no previous surgical experience were recruited. All participants completed a self-reported questionnaire that asked them to detail their video game experience. They then underwent assessment of their psychomotor, visuospatial, and perceptual abilities using previously validated tests. The results were analyzed using independent samples t tests to compare means and linear regression curves for subsequent analysis. Students who played video games for at least 7 hours per week demonstrated significantly better psychomotor skills than students who did not play video games regularly. However, there was no difference on measures of visuospatial and perceptual abilities. There was no correlation between psychomotor tests and visuospatial or perceptual tests. Regular video gaming correlates positively with psychomotor ability, but it does not seem to influence visuospatial or perceptual ability. This study suggests that video game experience might be beneficial to a future career in surgery. It also suggests that relevant surgical skills may be gained usefully outside the operating room in activities that are not

Visible continuum pulses based on enhanced dispersive wave generation for endogenous fluorescence imaging.

Science.gov (United States)

Cui, Quan; Chen, Zhongyun; Liu, Qian; Zhang, Zhihong; Luo, Qingming; Fu, Ling

2017-09-01

In this study, we demonstrate endogenous fluorescence imaging using visible continuum pulses based on 100-fs Ti:sapphire oscillator and a nonlinear photonic crystal fiber. Broadband (500-700 nm) and high-power (150 mW) continuum pulses are generated through enhanced dispersive wave generation by pumping femtosecond pulses at the anomalous dispersion region near zero-dispersion wavelength of high-nonlinear photonic crystal fibers. We also minimize the continuum pulse width by determining the proper fiber length. The visible-wavelength two-photon microscopy produces NADH and tryptophan images of mice tissues simultaneously. Our 500-700 nm continuum pulses support extending nonlinear microscopy to visible wavelength range that is inaccessible to 100-fs Ti:sapphire oscillators and other applications requiring visible laser pulses.

Gaming to see: action video gaming is associated with enhanced processing of masked stimuli.

Science.gov (United States)

Pohl, Carsten; Kunde, Wilfried; Ganz, Thomas; Conzelmann, Annette; Pauli, Paul; Kiesel, Andrea

2014-01-01

Recent research revealed that action video game players outperform non-players in a wide range of attentional, perceptual and cognitive tasks. Here we tested if expertise in action video games is related to differences regarding the potential of shortly presented stimuli to bias behavior. In a response priming paradigm, participants classified four animal pictures functioning as targets as being smaller or larger than a reference frame. Before each target, one of the same four animal pictures was presented as a masked prime to influence participants' responses in a congruent or incongruent way. Masked primes induced congruence effects, that is, faster responses for congruent compared to incongruent conditions, indicating processing of hardly visible primes. Results also suggested that action video game players showed a larger congruence effect than non-players for 20 ms primes, whereas there was no group difference for 60 ms primes. In addition, there was a tendency for action video game players to detect masked primes for some prime durations better than non-players. Thus, action video game expertise may be accompanied by faster and more efficient processing of shortly presented visual stimuli.

Gaming to see: Action Video Gaming is associated with enhanced processing of masked stimuli

Directory of Open Access Journals (Sweden)

Carsten ePohl

2014-02-01

Full Text Available Recent research revealed that action video game players outperform non-players in a wide range of attentional, perceptual and cognitive tasks. Here we tested if expertise in action video games is related to differences regarding the potential of shortly presented stimuli to bias behaviour. In a response priming paradigm, participants classified four animal pictures functioning as targets as being smaller or larger than a reference frame. Before each target, one of the same four animal pictures was presented as a masked prime to influence participants’ responses in a congruent or incongruent way. Masked primes induced congruence effects, that is, faster responses for congruent compared to incongruent conditions, indicating processing of hardly visible primes. Results also suggested that action video game players showed a larger congruence effect than non-players for 20 ms primes, whereas there was no group difference for 60 ms primes. In addition, there was a tendency for action video game players to detect masked primes for some prime durations better than non-players. Thus, action video game expertise may be accompanied by faster and more efficient processing of shortly presented visual stimuli.

Video Analytics for Business Intelligence

CERN Document Server

Porikli, Fatih; Xiang, Tao; Gong, Shaogang

2012-01-01

Closed Circuit TeleVision (CCTV) cameras have been increasingly deployed pervasively in public spaces including retail centres and shopping malls. Intelligent video analytics aims to automatically analyze content of massive amount of public space video data and has been one of the most active areas of computer vision research in the last two decades. Current focus of video analytics research has been largely on detecting alarm events and abnormal behaviours for public safety and security applications. However, increasingly CCTV installations have also been exploited for gathering and analyzing business intelligence information, in order to enhance marketing and operational efficiency. For example, in retail environments, surveillance cameras can be utilised to collect statistical information about shopping behaviour and preference for marketing (e.g., how many people entered a shop; how many females/males or which age groups of people showed interests to a particular product; how long did they stay in the sho...

Automatic enhancement of skin fluorescence localization due to refractive index matching

Science.gov (United States)

Churmakov, Dmitry Y.; Meglinski, Igor V.; Piletsky, Sergey A.; Greenhalgh, Douglas A.

2004-07-01

Fluorescence diagnostic techniques are notable amongst many other optical methods, as they offer high sensitivity and non-invasive measurements of tissue properties. However, a combination of multiple scattering and physical heterogeneity of biological tissues hampers the interpretation of the fluorescence measurements. The analyses of the spatial distribution of endogenous and exogenous fluorophores excitations within tissues and their contribution to the detected signal localization are essential for many applications. We have developed a novel Monte Carlo technique that gives a graphical perception of how the excitation and fluorescence detected signal are localized in tissues. Our model takes into account spatial distribution of fluorophores and their quantum yields. We demonstrate that matching of the refractive indices of ambient medium and topical skin layer improves spatial localization of the detected fluorescence signal within the tissue. This result is consistent with the recent conclusion that administering biocompatible agents results in higher image contrast.

Ag-protein plasmonic architectures for surface plasmon-coupled emission enhancements and Fabry-Perot mode-coupled directional fluorescence emission

Science.gov (United States)

Badiya, Pradeep Kumar; Patnaik, Sai Gourang; Srinivasan, Venkatesh; Reddy, Narendra; Manohar, Chelli Sai; Vedarajan, Raman; Mastumi, Noriyoshi; Belliraj, Siva Kumar; Ramamurthy, Sai Sathish

2017-10-01

We report the use of silver decorated plant proteins as spacer material for augmented surface plasmon-coupled emission (120-fold enhancement) and plasmon-enhanced Raman scattering. We extracted several proteins from different plant sources [Triticum aestivum (TA), Aegle marmelos (AM), Ricinus communis (RC), Jatropha curcas (JC) and Simarouba glauca (SG)] followed by evaluation of their optical properties and simulations to rationalize observed surface plasmon resonance. Since the properties exhibited by protein thin films is currently gaining research interest, we have also carried out simulation studies with Ag-protein biocomposites as spacer materials in metal-dielectric-metal planar microcavity architecture for guided emission of Fabry-Perot mode-coupled fluorescence.

Creating an animation-enhanced video library of hepato-pancreato-biliary and transplantation surgical procedures.

Science.gov (United States)

Fung, Albert; Kelly, Paul; Tait, Gordon; Greig, Paul D; McGilvray, Ian D

2016-01-01

The potential for integrating real-time surgical video and state-of-the art animation techniques has not been widely applied to surgical education. This paper describes the use of new technology for creating videos of liver, pancreas and transplant surgery, annotating them with 3D animations, resulting in a freely-accessible online resource: The Toronto Video Atlas of Liver, Pancreas and Transplant Surgery ( http://tvasurg.ca ). The atlas complements the teaching provided to trainees in the operating room, and the techniques described in this study can be readily adapted by other surgical training programmes.

The design of red-blue 3D video fusion system based on DM642

Science.gov (United States)

Fu, Rongguo; Luo, Hao; Lv, Jin; Feng, Shu; Wei, Yifang; Zhang, Hao

2016-10-01

Aiming at the uncertainty of traditional 3D video capturing including camera focal lengths, distance and angle parameters between two cameras, a red-blue 3D video fusion system based on DM642 hardware processing platform is designed with the parallel optical axis. In view of the brightness reduction of traditional 3D video, the brightness enhancement algorithm based on human visual characteristics is proposed and the luminance component processing method based on YCbCr color space is also proposed. The BIOS real-time operating system is used to improve the real-time performance. The video processing circuit with the core of DM642 enhances the brightness of the images, then converts the video signals of YCbCr to RGB and extracts the R component from one camera, so does the other video and G, B component are extracted synchronously, outputs 3D fusion images finally. The real-time adjustments such as translation and scaling of the two color components are realized through the serial communication between the VC software and BIOS. The system with the method of adding red-blue components reduces the lost of the chrominance components and makes the picture color saturation reduce to more than 95% of the original. Enhancement algorithm after optimization to reduce the amount of data fusion in the processing of video is used to reduce the fusion time and watching effect is improved. Experimental results show that the system can capture images in near distance, output red-blue 3D video and presents the nice experiences to the audience wearing red-blue glasses.

Retail video analytics: an overview and survey

Science.gov (United States)

Connell, Jonathan; Fan, Quanfu; Gabbur, Prasad; Haas, Norman; Pankanti, Sharath; Trinh, Hoang

2013-03-01

Today retail video analytics has gone beyond the traditional domain of security and loss prevention by providing retailers insightful business intelligence such as store traffic statistics and queue data. Such information allows for enhanced customer experience, optimized store performance, reduced operational costs, and ultimately higher profitability. This paper gives an overview of various camera-based applications in retail as well as the state-ofthe- art computer vision techniques behind them. It also presents some of the promising technical directions for exploration in retail video analytics.

For Video Streaming/Delivery: Is HTML5 the Real Fix?

Directory of Open Access Journals (Sweden)

John Millard

2013-10-01

Full Text Available The general movement towards streaming or playing videos on the web has grown exponentially in the last decade. The combination of new streaming technologies and faster Internet connections continue to provide enhanced and robust user experience for video content. For many organizations, adding videos on their websites has transitioned from a “cool” feature to a mission critical service. Some of the benefits in putting videos online include: to engage and convert visitors, to raise awareness or drive interest, to share inspirational stories or recent unique events, etc. Along with the growth in the use and need for video content on the web; delivering videos online also remains a messy activity for developers and web teams. Examples of existing challenges include creating more accessible videos with captions and delivering content (using adaptive streaming for the diverse range of mobile and tablet devices. In this article, we report on the decision-making and early results in using the Kaltura video platform in two popular library platforms: CONTENTdm and DSpace.

Study on silicon oxide coated on silver nanocrystal to enhance fluorescence intensity of rare earth complexes

Energy Technology Data Exchange (ETDEWEB)

Qu, Yan-rong; Lin, Xue-mei; Wang, Ai-ling; Wang, Zhong-xia; Kang, Jie; Chu, Hai-bin, E-mail: binghai99@gmail.com; Zhao, Yong-liang, E-mail: hxzhaoyl@163.com

2014-10-15

Twelve kinds of rare earth complexes were synthesized using halo-benzoic acid as anion ligand and Sm{sup 3+} and Dy{sup 3+} as central ions, respectively. The complexes were characterized by elemental analysis, rare earth coordination titration and electrospray ionization mass spectra, from which the compositions of the complexes were confirmed to be RE(p-FBA){sub 3}·H{sub 2}O, RE(p-ClBA){sub 3}·2H{sub 2}O, RE(p-BrBA){sub 3}·H{sub 2}O, RE(o-FBA){sub 3}·2H{sub 2}O, RE(o-ClBA){sub 3}·H{sub 2}O, RE(o-BrBA){sub 3}·H{sub 2}O (RE=Sm{sup 3+}, Dy{sup 3+}). Besides, IR spectra and UV–visible absorption spectroscopy indicated that the carboxyl oxygen atoms of ligands coordinated to the rare earth ions. Moreover, Ag@SiO{sub 2} core–shell nanoparticles (NPs) were prepared via a modified Stöber method. The average diameters of silver cores were typically between 60 nm and 70 nm, and the thicknesses of the SiO{sub 2} shells were around 10 nm, 15 nm and 25 nm, respectively. The influence of Ag@SiO{sub 2} NPs on the luminescence properties of the rare earth complexes showed that the luminescence intensities of rare earth complexes were enhanced remarkably. As the thickness of SiO{sub 2} shell increases in the range of 10–25 nm, the effect of metal-enhanced fluorescence become obvious. The mechanism of the changes of the fluorescence intensity is also discussed. - Highlights: • Among 10–25 nm, the thicker the shell thickness, the better the fluorescence effect. • The strong the intensity of the pure complexes, the smaller the multiple enhanced. • The intensity of Sm(p-BrBA){sub 3}·H{sub 2}O is the strongest among Sm(p-XBA){sub 3}·nH{sub 2}O complexes. • The intensity of Dy(p-ClBA){sub 3}·2H{sub 2}O is the strongest among Dy(p-XBA){sub 3}·nH{sub 2}O complexes. • When halogen is in o-position, the intensity of RE(o-ClBA){sub 3}·H{sub 2}O is the strongest.

Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion

Energy Technology Data Exchange (ETDEWEB)

Liu Zhengqing; Liu Shaopu; Yin Pengfei [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); He Youqiu, E-mail: heyq@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

2012-10-01

Graphical abstract: Glyphosate (Glyp) had been used to modify the surface of CdTe/CdS QDs, resulting in the enhancement of fluorescence intensity. The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+} based on the fluorescence quenching. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. Black-Right-Pointing-Pointer The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. Black-Right-Pointing-Pointer A new fluorescent sensor for copper ion was developed based on the prepared QDs. Black-Right-Pointing-Pointer The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu{sup 2+} determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core-shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu{sup 2+} between 2.4 Multiplication-Sign 10{sup -2} {mu}g mL{sup -1} and 28 {mu}g mL{sup -1}, with a detection limit of 1.3 Multiplication-Sign 10{sup -3} {mu}g mL{sup -1} (3{delta}). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+}. The fluorescent probe was successfully used for the determination of Cu{sup 2+} in environmental samples. The mechanism of reaction was also discussed.

Fluorescent sensors based on bacterial fusion proteins

International Nuclear Information System (INIS)

Mateu, Batirtze Prats; Pum, Dietmar; Sleytr, Uwe B; Toca-Herrera, José L; Kainz, Birgit

2014-01-01

Fluorescence proteins are widely used as markers for biomedical and technological purposes. Therefore, the aim of this project was to create a fluorescent sensor, based in the green and cyan fluorescent protein, using bacterial S-layers proteins as scaffold for the fluorescent tag. We report the cloning, expression and purification of three S-layer fluorescent proteins: SgsE-EGFP, SgsE-ECFP and SgsE-13aa-ECFP, this last containing a 13-amino acid rigid linker. The pH dependence of the fluorescence intensity of the S-layer fusion proteins, monitored by fluorescence spectroscopy, showed that the ECFP tag was more stable than EGFP. Furthermore, the fluorescent fusion proteins were reassembled on silica particles modified with cationic and anionic polyelectrolytes. Zeta potential measurements confirmed the particle coatings and indicated their colloidal stability. Flow cytometry and fluorescence microscopy showed that the fluorescence of the fusion proteins was pH dependent and sensitive to the underlying polyelectrolyte coating. This might suggest that the fluorescent tag is not completely exposed to the bulk media as an independent moiety. Finally, it was found out that viscosity enhanced the fluorescence intensity of the three fluorescent S-layer proteins. (paper)

Fabrication of Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2@Y_2O_3:Eu nanocomposites with enhanced fluorescence

International Nuclear Information System (INIS)

Li, Huiqin; Kang, Jianmiao; Yang, Jianhui; Wu, Biao

2016-01-01

Herein, Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2@Y_2O_3:Eu nanocomposites are synthesized through layer-by-layer assembly technology. Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2 core–shell nanospheres were prepared at first in the presence of CTAB in aqueous solution system by the modified one-pot method. A chemical precipitation method and a succeeding calcination process were adopted to the growth of Y_2O_3:Eu shells on the surfaces of Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2 core–shell nanospheres. The structure, morphology and composition of the nanocomposites were confirmed by XRD, TEM and UV–vis absorption spectrum. The prepared Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2@Y_2O_3:Eu nanocomposites have showed the emission intensity enhances to 6.23 times at 30 nm thickness of the silica spacer between the core of Au nanoparticle and the shell of Y_2O_3:Eu. According to the observations of fluorescent lifetime and the modeling of local electric field, the metal-enhanced and quenched fluorescence is closely related with the enhancement of excitation and radiative decay rate and the quenching by NRET comes as a result of competition between the distance-dependent mechanisms. This kind of multifunctional inorganic material will be widely used in electronics, biology and medical drug loading, etc. - Highlights: • Fabrication of Au_n_a_n_o_p_a_r_t_i_c_l_e@mSiO_2@Y_2O_3:Eu nanocomposites with core-spacer-shell structure. • The controllable fluorescence is achieved by adjusting the spacer thickness of silica. • The fluorescence enhancement is 6.23-fold at an optimal spacer thickness about 30 nm. • The metal-enhanced fluorescence mechanism is proposed.

Video profile monitor diagnostic system for GTA

International Nuclear Information System (INIS)

Sandovil, D.P.; Garcia, R.C.; Gilpatrick, J.D.; Johnson, K.F.; Shinas, M.A.; Wright, R.; Yuan, V.; Zander, M.E.

1992-01-01

This paper describes a video diagnostic system used to measure the beam profile and position of the Ground Test Accelerator 2.5 MeV H - ion beam as it exits the intermediate matching section. Inelastic collisions between H - ions and residual nitrogen in the vacuum chamber cause the nitrogen to fluoresce. The resulting light is captured through transport optics by an intensified CCD camera and is digitized. Real-time beam profile images are displayed and stored for detailed analysis. Analyzed data showing resolutions for both position and profile measurements will also be presented. (Author) 5 refs., 7 figs

Photonic reagents for concentration measurement of flu-orescent proteins with overlapping spectra

Science.gov (United States)

Goun, Alexei; Bondar, Denys I.; Er, Ali O.; Quine, Zachary; Rabitz, Herschel A.

2016-05-01

By exploiting photonic reagents (i.e., coherent control by shaped laser pulses), we employ Optimal Dynamic Discrimination (ODD) as a novel means for quantitatively characterizing mixtures of fluorescent proteins with a large spectral overlap. To illustrate ODD, we simultaneously measured concentrations of in vitro mixtures of Enhanced Blue Fluorescent Protein (EBFP) and Enhanced Cyan Fluorescent Protein (ECFP). Building on this foundational study, the ultimate goal is to exploit the capabilities of ODD for parallel monitoring of genetic and protein circuits by suppressing the spectral cross-talk among multiple fluorescent reporters.

Hyper-spectral modulation fluorescent imaging using double acousto-optical tunable filter based on TeO2-crystals

International Nuclear Information System (INIS)

Zaytsev, Kirill I; Perchik, Alexey V; Chernomyrdin, Nikita V; Yurchenko, Stanislav O; Kudrin, Konstantin G; Reshetov, Igor V

2015-01-01

We have proposed a method for hyper-spectral fluorescent imaging based on acousto-optical filtering. The object of interest was pumped using ultraviolet radiation of mercury lamp equipped with monochromatic excitation filter with the window of transparency centered at 365 nm. Double TeO 2 -based acousto-optical filter, tunable in range from 430 to 780 nm and having 2 nm bandwidth of spectral transparency, was used in order to detect quasimonochromatic images of object fluorescence. Modulating of ultraviolet pump intensity was used in order to reduce an impact of non-fluorescent background on the sample fluorescent imaging. The technique for signal-to-noise ratio improvement, based on fluorescence intensity estimation via digital processing of modulated video sequence of fluorescent object, was introduced. We have implemented the proposed technique for the test sample studying and we have discussed its possible applications

Learning, attentional control and action video games

Science.gov (United States)

Green, C.S.; Bavelier, D.

2012-01-01

While humans have an incredible capacity to acquire new skills and alter their behavior as a result of experience, enhancements in performance are typically narrowly restricted to the parameters of the training environment, with little evidence of generalization to different, even seemingly highly related, tasks. Such specificity is a major obstacle for the development of many real-world training or rehabilitation paradigms, which necessarily seek to promote more general learning. In contrast to these typical findings, research over the past decade has shown that training on ‘action video games’ produces learning that transfers well beyond the training task. This has led to substantial interest among those interested in rehabilitation, for instance, after stroke or to treat amblyopia, or training for various precision-demanding jobs, for instance, endoscopic surgery or piloting unmanned aerial drones. Although the predominant focus of the field has been on outlining the breadth of possible action-game-related enhancements, recent work has concentrated on uncovering the mechanisms that underlie these changes, an important first step towards the goal of designing and using video games for more definite purposes. Game playing may not convey an immediate advantage on new tasks (increased performance from the very first trial), but rather the true effect of action video game playing may be to enhance the ability to learn new tasks. Such a mechanism may serve as a signature of training regimens that are likely to produce transfer of learning. PMID:22440805

Advantages of video trigger in problem-based learning.

Science.gov (United States)

Chan, Lap Ki; Patil, Nivritti G; Chen, Julie Y; Lam, Jamie C M; Lau, Chak S; Ip, Mary S M

2010-01-01

Traditionally, paper cases are used as 'triggers' to stimulate learning in problem-based learning (PBL). However, video may be a better medium because it preserves the original language, encourages the active extraction of information, avoids depersonalization of patients and allows direct observation of clinical consultations. In short, it exposes the students to the complexity of actual clinical problems. The study aims to find out whether students and facilitators who are accustomed to paper cases would prefer video triggers or paper cases and the reasons for their preference. After students and facilitators had completed a video PBL tutorial, their responses were measured by a structured questionnaire using a modified Likert scale. A total of 257 students (92%) and 26 facilitators (100%) responded. The majority of students and facilitators considered that using video triggers could enhance the students' observational powers and clinical reasoning, help them to integrate different information and better understand the cases and motivate them to learn. They found PBL using video triggers more interesting and preferred it to PBL using paper cases. Video triggers are preferred by both students and facilitators over paper cases in PBL.

Structured student-generated videos for first-year students at a dental school in Malaysia.

Science.gov (United States)

Omar, Hanan; Khan, Saad A; Toh, Chooi G

2013-05-01

Student-generated videos provide an authentic learning experience for students, enhance motivation and engagement, improve communication skills, and improve collaborative learning skills. This article describes the development and implementation of a student-generated video activity as part of a knowledge, observation, simulation, and experience (KOSE) program at the School of Dentistry, International Medical University, Kuala Lumpur, Malaysia. It also reports the students' perceptions of an activity that introduced first-year dental students (n=44) to clinical scenarios involving patients and dental team aiming to improve professional behavior and communication skills. The learning activity was divided into three phases: preparatory phase, video production phase, and video-watching. Students were organized into five groups and were instructed to generate videos addressing given clinical scenarios. Following the activity, students' perceptions were assessed with a questionnaire. The results showed that 86 percent and 88 percent, respectively, of the students agreed that preparation of the activity enhanced their understanding of the role of dentists in provision of health care and the role of enhanced teamwork. In addition, 86 percent and 75 percent, respectively, agreed that the activity improved their communication and project management skills. Overall, the dental students perceived that the student-generated video activity was a positive experience and enabled them to play the major role in driving their learning process.

Enhancing Perceived Quality of Compressed Images and Video with Anisotropic Diffusion and Fuzzy Filtering

DEFF Research Database (Denmark)

Nadernejad, Ehsan; Korhonen, Jari; Forchhammer, Søren

2013-01-01

and subjective results on JPEG compressed images, as well as MJPEG and H.264/AVC compressed video, indicate that the proposed algorithms employing directional and spatial fuzzy filters achieve better artifact reduction than other methods. In particular, robust improvements with H.264/AVC video have been gained...

Target-triggered signal turn-on detection of prostate specific antigen based on metal-enhanced fluorescence of Ag@SiO2@SiO2-RuBpy composite nanoparticles

Science.gov (United States)

Deng, Yun-Liang; Xu, Dang-Dang; Pang, Dai-Wen; Tang, Hong-Wu

2017-02-01

A three-layer core-shell nanostructure consisting of a silver core, a silica spacer, and a fluorescent dye RuBpy-doped outer silica layer was fabricated, and the optimal metal-enhanced fluorescence (MEF) distance was explored through adjusting the thickness of the silica spacer. The results show that the optimal distance is ˜10.4 nm with the maximum fluorescence enhancement factor 2.12. Then a new target-triggered MEF ‘turn-on’ strategy based on the optimized composite nanoparticles was successfully constructed for quantitative detection of prostate specific antigen (PSA), by using RuBpy as the energy donor and BHQ-2 as the acceptor. The hybridization of the complementary DNA of PSA-aptamer immobilized on the surface of the MEF nanoparticles with PSA-aptamer modified with BHQ-2, brought BHQ-2 in close proximity to RuBpy-doped silica shell and resulted in the decrease of fluorescence. In the presence of target PSA molecules, the BHQ-PSA aptamer is dissociated from the surface of the nanoparticles with the fluorescence switched on. Therefore, the assay of PSA was achieved by measuring the varying fluorescence intensity. The results show that PSA can be detected in the range of 1-100 ng ml-1 with a detection limit of 0.20 ng ml-1 (6.1 pM), which is 6.7-fold increase of that using hollow RuBpy-doped silica nanoparticles. Moreover, satisfactory results were obtained when PSA was detected in 1% serum.

Research of real-time video processing system based on 6678 multi-core DSP

Science.gov (United States)

Li, Xiangzhen; Xie, Xiaodan; Yin, Xiaoqiang

2017-10-01

In the information age, the rapid development in the direction of intelligent video processing, complex algorithm proposed the powerful challenge on the performance of the processor. In this article, through the FPGA + TMS320C6678 frame structure, the image to fog, merge into an organic whole, to stabilize the image enhancement, its good real-time, superior performance, break through the traditional function of video processing system is simple, the product defects such as single, solved the video application in security monitoring, video, etc. Can give full play to the video monitoring effectiveness, improve enterprise economic benefits.

The Impact of Recreational Video Game Play on Children's and Adolescents' Cognition

Science.gov (United States)

Blumberg, Fran C.; Altschuler, Elizabeth A.; Almonte, Debby E.; Mileaf, Maxwell I.

2013-01-01

Current empirical findings show linkages between recreational video game play and enhanced cognitive skills, primarily among young adults. However, consideration of this linkage among children and adolescents is sparse. Thus, discussions about facilitating transfer of cognitive skills from video game play to academic tasks among children and…

Video-modelling to improve task completion in a child with autism.

Science.gov (United States)

Rayner, Christopher Stephen

2010-01-01

To evaluate the use of video modelling as an intervention for increasing task completion for individuals with autism who have high support needs. A 12-year-old-boy with autism received video modelling intervention on two routines (unpacking his bag and brushing his teeth). Use of the video modelling intervention led to rapid increases in the percentage of steps performed in the unpacking his bag sequence and these gains generalized to packing his bag prior to departure from school. There was limited success in the use of the video modelling intervention for teaching the participant to brush his teeth. Video modelling can be successfully applied to enhance daily functioning in a classroom environment for students with autism and high support needs.

Identification of bacteria used for microbial enhanced oil recovery process by fluorescence in situ hybridization technique

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, K.; Tanaka, S.; Otsuka, M. [Kansai Research Institute, Kyoto (Japan). Lifescience Lab.; Yonebayashi, H. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

2000-01-01

A fluorescence in situ hybridization (FISH) technique using 16S rRNA-targeted oligonucleotide probes was developed for rapid detection of microorganisms for use in the microbial enhancement of oil recovery (MEOR) process. Two microorganisms, Enterobacter cloacae TRC-322 and Bacillus licheniformis TRC-18-2-a, were selected from a collection of Enterobacter sp. and Bacillus sp. which were screened in previous studies as candidate microorganisms for injection, and were used for this experiment. Oligonucleotide probes, design based on specific sequences in the 16S rRNA gene were labeled with either fluorescein isothiocyanate (FITC), or 6-car-boxy-X-rhodamine (ROX), and were allowed to hybridize with fixed cells of the two microorganisms noted above. The fluorescence signal emitted from each microorganism cells could clearly be detected by an epifluorescence microscope. Moreover, E. cloacae TRC-322 and B, licheniformis TRC-18-2-a, suspended in actual reservoir brine, including inorganic salts, oil and aboriginal cells of the reservoir brine, could be detected directly by this hybridization method, without the need for cultivation and isolation. (author)

See hear: psychological effects of music and music-video during treadmill running.

Science.gov (United States)

Hutchinson, Jasmin C; Karageorghis, Costas I; Jones, Leighton

2015-04-01

There is a paucity of work addressing the distractive, affect-enhancing, and motivational influences of music and video in combination during exercise. We examined the effects of music and music-and-video on a range of psychological and psychophysical variables during treadmill running at intensities above and below ventilatory threshold (VT). Participants (N = 24) exercised at 10 % of maximal capacity below VT and 10 % above under music-only, music-and-video, and control conditions. There was a condition × intensity × time interaction for perceived activation and state motivation, and an intensity × time interaction for state attention, perceived exertion (RPE), and affective valence. The music-and-video condition elicited the highest levels of dissociation, lowest RPE, and most positive affective responses regardless of exercise intensity. Attentional manipulations influence psychological and psychophysical variables at exercise intensities above and below VT, and this effect is enhanced by the combined presentation of auditory and visual stimuli.

Highly selective ratiometric fluorescent detection of Fe{sup 3+} with a polyphenyl derivative

Energy Technology Data Exchange (ETDEWEB)

Li, Zhan-Xian, E-mail: lizx@zzu.edu.cn [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China); Zhou, Wan; Zhang, Li-Feng; Yuan, Rui-Li; Liu, Xing-Jiang; Wei, Liu-He [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China); Yu, Ming-Ming, E-mail: yumm@zzu.edu.cn [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China)

2013-04-15

Compared with other fluorescent probes, ratiometric fluorescence responses are more attractive because the ratio between the two emission intensities can be used to measure the analyte concentration and provide a built-in correction for environmental effects. A highly selective and sensitive ratiometric fluorescent probe for Fe{sup 3+} was synthesized, which exhibits an enhanced fluorescence with a large red-shift in emission from 361 to 455 nm upon addition of Fe{sup 3+}. The red-shift of the emission peak can be ascribed to the reformed orbital, and the increase of emission intensity may be ascribed to the inhibition of the rotation of C–C bonds between each two aromatic rings. -- Graphical abstract: A highly selective and sensitive ratiometric fluorescent probe for Fe{sup 3+} was synthesized, which exhibits an enhanced fluorescence with a large red-shift in emission from 361 to 455 nm upon addition of Fe{sup 3+}. Highlights: ► A ratiometric fluorescent probe for Fe{sup 3+} was synthesized. ► The probe exhibits an enhanced fluorescence with a red-shift upon addition of Fe{sup 3+}. ► Inhibition of the rotation of C–C bonds was possible detection mechanism for Fe{sup 3+}.

Random Linear Network Coding for 5G Mobile Video Delivery

Directory of Open Access Journals (Sweden)

Dejan Vukobratovic

2018-03-01

Full Text Available An exponential increase in mobile video delivery will continue with the demand for higher resolution, multi-view and large-scale multicast video services. Novel fifth generation (5G 3GPP New Radio (NR standard will bring a number of new opportunities for optimizing video delivery across both 5G core and radio access networks. One of the promising approaches for video quality adaptation, throughput enhancement and erasure protection is the use of packet-level random linear network coding (RLNC. In this review paper, we discuss the integration of RLNC into the 5G NR standard, building upon the ideas and opportunities identified in 4G LTE. We explicitly identify and discuss in detail novel 5G NR features that provide support for RLNC-based video delivery in 5G, thus pointing out to the promising avenues for future research.

Feasibility of video codec algorithms for software-only playback

Science.gov (United States)

Rodriguez, Arturo A.; Morse, Ken

1994-05-01

Software-only video codecs can provide good playback performance in desktop computers with a 486 or 68040 CPU running at 33 MHz without special hardware assistance. Typically, playback of compressed video can be categorized into three tasks: the actual decoding of the video stream, color conversion, and the transfer of decoded video data from system RAM to video RAM. By current standards, good playback performance is the decoding and display of video streams of 320 by 240 (or larger) compressed frames at 15 (or greater) frames-per- second. Software-only video codecs have evolved by modifying and tailoring existing compression methodologies to suit video playback in desktop computers. In this paper we examine the characteristics used to evaluate software-only video codec algorithms, namely: image fidelity (i.e., image quality), bandwidth (i.e., compression) ease-of-decoding (i.e., playback performance), memory consumption, compression to decompression asymmetry, scalability, and delay. We discuss the tradeoffs among these variables and the compromises that can be made to achieve low numerical complexity for software-only playback. Frame- differencing approaches are described since software-only video codecs typically employ them to enhance playback performance. To complement other papers that appear in this session of the Proceedings, we review methods derived from binary pattern image coding since these methods are amenable for software-only playback. In particular, we introduce a novel approach called pixel distribution image coding.

Endogenous and exogenous fluorescence of gastrointestinal tumors: initial clinical observations

Science.gov (United States)

Borisova, Ekaterina; Plamenova, Lilia; Keremedchiev, Momchil; Vladimirov, Borislav; Avramov, Latchezar

2013-03-01

The limitations of standard endoscopy for detection and evaluation of cancerous changes in gastrointestinal tract (GIT) are significant challenge and initiate development of new diagnostic modalities. Therefore many spectral and optical techniques are applied recently into the clinical practice for obtaining qualitatively and quantitatively new data from gastrointestinal neoplasia with different level of clinical applicability and diagnostic success. One of the most promising approaches is fluorescence detection using naturally existing fluorescent molecules or added fluorescent markers. Deltaaminolevulinic acid / protoporphyrin IX is applied for exogenous fluorescent tumor detection in the upper part of gastrointestinal tract. The 5-ALA is administered per os six hours before measurements at dose 20mg/kg weight. Highpower light-emitting diode at 405 nm is used as a source and the excitation light is passed through the light-guide of standard video-endoscopic system to obtain 2-D visualization. Both kinds of spectra - autofluorescence signals and protoporphyrin IX signal are recorded and stored using a fiber-optic microspectrometer, as in endoscopy instrumental channel a fiber is applied to return information about fluorescence signals. In such way 1-D detection and 2-D visualization of the lesions' fluorescence are received. The results from in vivo detection show significant differentiation between normal and abnormal tissues in 1-D spectroscopic regime, but only moderate discrimination in 2-D imaging.

Using Video To Promote and To Enhance Active Student Participation in English Literature Classes.

Science.gov (United States)

Finkelstein, Marci

1995-01-01

Video is an effective educational tool in English Literature classes when the teacher is creative in its application. Video has five specific properties which make it an effective instructional device: (1) condensing or expanding an experience; (2) making the invisible visible; (3) taking the viewers where they could not go; (4) eliciting…

Determination of ATP as a fluorescence probe with europium(III)-doxycycline.

Science.gov (United States)

Hou, Faju; Wang, Xiaolei; Jiang, Chongqiu

2005-03-01

A new spectrofluorimetric method has been developed for the determination of adenosine disodium triphosphate (ATP). We studied the interactions between the doxycycline (DC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-visible absorption and fluorescence spectra. Using doxycycline (DC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP could remarkably enhance the fluorescence intensity of the DC-Eu3+ complex at lambda = 612 nm. The enhanced fluorescence intensity of the Eu3+ ion was in proportion to the concentration of ATP. The optimum conditions for the determination of ATP were also investigated. The linear ranges for ATP were 1.00 x 10(-7) - 2.00 x 10(-6) mol L(-1) with detection limits of 4.07 x 10(-8) mol L(-1). This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to the determination of ATP in samples. The mechanism of fluorescence enhancement between the doxycycline (DC)-Eu3+ complex and ATP was also studied.

Content-based video retrieval by example video clip

Science.gov (United States)

Dimitrova, Nevenka; Abdel-Mottaleb, Mohamed

1997-01-01

This paper presents a novel approach for video retrieval from a large archive of MPEG or Motion JPEG compressed video clips. We introduce a retrieval algorithm that takes a video clip as a query and searches the database for clips with similar contents. Video clips are characterized by a sequence of representative frame signatures, which are constructed from DC coefficients and motion information (`DC+M' signatures). The similarity between two video clips is determined by using their respective signatures. This method facilitates retrieval of clips for the purpose of video editing, broadcast news retrieval, or copyright violation detection.

Micellar Enhanced Three-Dimensional Excitation-Emission Matrix Fluorescence for Rapid Determination of Antihypertensives in Human Plasma with Aid of Second-Order Calibration Methods

Directory of Open Access Journals (Sweden)

Hai-Yan Fu

2015-01-01

Full Text Available A highly sensitive three-dimensional excitation-emission fluorescence method was proposed to determine antihypertensives including valsartan and amlodipine besylate in human plasma with the aid of second-order calibration methods based on parallel factor analysis (PARAFAC and alternating trilinear decomposition (ATLD algorithms. Antihypertensives with weak fluorescent can be transformed into a strong fluorescent property by changing microenvironment in samples using micellar enhanced surfactant. Both the adopted algorithms with second-order advantage can improve the resolution and directly attain antihypertensives concentration even in the presence of potential strong intrinsic fluorescence from human plasma. The satisfactory results can be achieved for valsartan and amlodipine besylate in complicated human plasma. Furthermore, some statistical parameters and figures of merit were evaluated to investigate the performance of the proposed method, and the accuracy and precision of the proposed method were also validated by the elliptical joint confidence region (EJCR test and repeatability analysis of intraday and interday assay. The proposed method could not only light a new avenue to directly determine valsartan or amlodipine besylate in human plasma, but also hold great potential to be extended as a promising alternative for more practical applications in the determination of weak fluorescent drugs.

Video Game Learning Dynamics: Actionable Measures of Multidimensional Learning Trajectories

Science.gov (United States)

Reese, Debbie Denise; Tabachnick, Barbara G.; Kosko, Robert E.

2015-01-01

Valid, accessible, reusable methods for instructional video game design and embedded assessment can provide actionable information enhancing individual and collective achievement. Cyberlearning through game-based, metaphor-enhanced learning objects (CyGaMEs) design and embedded assessment quantify player behavior to study knowledge discovery and…

Immersive video

Science.gov (United States)

Moezzi, Saied; Katkere, Arun L.; Jain, Ramesh C.

1996-03-01

Interactive video and television viewers should have the power to control their viewing position. To make this a reality, we introduce the concept of Immersive Video, which employs computer vision and computer graphics technologies to provide remote users a sense of complete immersion when viewing an event. Immersive Video uses multiple videos of an event, captured from different perspectives, to generate a full 3D digital video of that event. That is accomplished by assimilating important information from each video stream into a comprehensive, dynamic, 3D model of the environment. Using this 3D digital video, interactive viewers can then move around the remote environment and observe the events taking place from any desired perspective. Our Immersive Video System currently provides interactive viewing and `walkthrus' of staged karate demonstrations, basketball games, dance performances, and typical campus scenes. In its full realization, Immersive Video will be a paradigm shift in visual communication which will revolutionize television and video media, and become an integral part of future telepresence and virtual reality systems.

Using Video Games to Enhance Motivation States in Online Education: Protocol for a Team-Based Digital Game.

Science.gov (United States)

Janssen, Anna; Shaw, Tim; Goodyear, Peter

2015-09-28

Video and computer games for education have been of interest to researchers for several decades. Over the last half decade, researchers in the health sector have also begun exploring the value of this medium. However, there are still many gaps in the literature regarding the effective use of video and computer games in medical education, particularly in relation to how learners interact with the platform, and how the games can be used to enhance collaboration. The objective of the study is to evaluate a team-based digital game as an educational tool for engaging learners and supporting knowledge consolidation in postgraduate medical education. A mixed methodology will be used in order to establish efficacy and level of motivation provided by a team-based digital game. Second-year medical students will be recruited as participants to complete 3 matches of the game at spaced intervals, in 2 evenly distributed teams. Prior to playing the game, participants will complete an Internet survey to establish baseline data. After playing the game, participants will voluntarily complete a semistructured interview to establish motivation and player engagement. Additionally, metrics collected from the game platform will be analyzed to determine efficacy. The research is in the preliminary stages, but thus far a total of 54 participants have been recruited into the study. Additionally, a content development group has been convened to develop appropriate content for the platform. Video and computer games have been demonstrated to have value for educational purposes. Significantly less research has addressed how the medium can be effectively utilized in the health sector. Preliminary data from this study would suggest there is an interest in games for learning in the medical student body. As such, it is beneficial to undertake further research into how these games teach and engage learners in order to evaluate their role in tertiary and postgraduate medical education in the future.

The effect of nonlocal dielectric response on the surface-enhanced Raman and fluorescence spectra of molecular systems

Science.gov (United States)

Wei, Yong; Pei, Huan; Li, Li; Zhu, Yanying

2018-06-01

We present a theoretical study on the influence of the nonlocal dielectric response on surface-enhanced resonant Raman scattering (SERRS) and fluorescence (SEF) spectra of a model molecule confined in the center of a Ag nanoparticle (NP) dimer. In the simulations, the nonlocal dielectric response caused by the electron–hole pair generation in Ag NPs was computed with the d-parameter theory, and the scattering spectra of a model molecule representing the commonly used fluorescent dye rhodamine 6G (R6G) were obtained by density-matrix calculations. The influence of the separation between Ag NP dimers on the damping rate and scattering spectra with and without the nonlocal response were systematically analyzed. The results show that the nonlocal dielectric response is very sensitive to the gap distance of the NP dimers, and it undergoes much faster decay with the increase of the separation than the radiative and energy transfer rates. The Raman and fluorescence peaks as simulated with the nonlocal dielectric response are relative weaker than that without the nonlocal effect for smaller NP separations because the extra decay rates of the nonlocal effect could reduce both the population of the excited state and the interband coherence between the ground and excited states. Our result also indicates that the nonlocal effect is more prominent on the SEF process than the SERRS process.

Talking Video in 'Everyday Life':Interactional Practices of Localising, Translating and Stretching Conduct in Reality TV Parenting Programmes

OpenAIRE

McIlvenny, Paul

2010-01-01

For better or worse, video technologies have made their way into many domains of social life, for example in the domain of therapeutics. Techniques such as Marte Meo, Video Interaction Guidance (ViG), Video-Enhanced Reflection on Communication, Video Home Training and Video intervention/prevention (VIP) all promote the use of video as a therapeutic tool. This paper focuses on media therapeutics and the various in situ uses of video technologies in the mass media for therapeutic purposes. Real...

Variable disparity-motion estimation based fast three-view video coding

Science.gov (United States)

Bae, Kyung-Hoon; Kim, Seung-Cheol; Hwang, Yong Seok; Kim, Eun-Soo

2009-02-01

In this paper, variable disparity-motion estimation (VDME) based 3-view video coding is proposed. In the encoding, key-frame coding (KFC) based motion estimation and variable disparity estimation (VDE) for effectively fast three-view video encoding are processed. These proposed algorithms enhance the performance of 3-D video encoding/decoding system in terms of accuracy of disparity estimation and computational overhead. From some experiments, stereo sequences of 'Pot Plant' and 'IVO', it is shown that the proposed algorithm's PSNRs is 37.66 and 40.55 dB, and the processing time is 0.139 and 0.124 sec/frame, respectively.

Video demystified

CERN Document Server

Jack, Keith

2004-01-01

This international bestseller and essential reference is the "bible" for digital video engineers and programmers worldwide. This is by far the most informative analog and digital video reference available, includes the hottest new trends and cutting-edge developments in the field. Video Demystified, Fourth Edition is a "one stop" reference guide for the various digital video technologies. The fourth edition is completely updated with all new chapters on MPEG-4, H.264, SDTV/HDTV, ATSC/DVB, and Streaming Video (Video over DSL, Ethernet, etc.), as well as discussions of the latest standards throughout. The accompanying CD-ROM is updated to include a unique set of video test files in the newest formats. *This essential reference is the "bible" for digital video engineers and programmers worldwide *Contains all new chapters on MPEG-4, H.264, SDTV/HDTV, ATSC/DVB, and Streaming Video *Completely revised with all the latest and most up-to-date industry standards.

Mutiple LDPC Decoding using Bitplane Correlation for Transform Domain Wyner-Ziv Video Coding

DEFF Research Database (Denmark)

Luong, Huynh Van; Huang, Xin; Forchhammer, Søren

2011-01-01

Distributed video coding (DVC) is an emerging video coding paradigm for systems which fully or partly exploit the source statistics at the decoder to reduce the computational burden at the encoder. This paper considers a Low Density Parity Check (LDPC) based Transform Domain Wyner-Ziv (TDWZ) video...... codec. To improve the LDPC coding performance in the context of TDWZ, this paper proposes a Wyner-Ziv video codec using bitplane correlation through multiple parallel LDPC decoding. The proposed scheme utilizes inter bitplane correlation to enhance the bitplane decoding performance. Experimental results...

Video pedagogy

OpenAIRE

Länsitie, Janne; Stevenson, Blair; Männistö, Riku; Karjalainen, Tommi; Karjalainen, Asko

2016-01-01

The short film is an introduction to the concept of video pedagogy. The five categories of video pedagogy further elaborate how videos can be used as a part of instruction and learning process. Most pedagogical videos represent more than one category. A video itself doesn’t necessarily define the category – the ways in which the video is used as a part of pedagogical script are more defining factors. What five categories did you find? Did you agree with the categories, or are more...

Learning, attentional control, and action video games.

Science.gov (United States)

Green, C S; Bavelier, D

2012-03-20

While humans have an incredible capacity to acquire new skills and alter their behavior as a result of experience, enhancements in performance are typically narrowly restricted to the parameters of the training environment, with little evidence of generalization to different, even seemingly highly related, tasks. Such specificity is a major obstacle for the development of many real-world training or rehabilitation paradigms, which necessarily seek to promote more general learning. In contrast to these typical findings, research over the past decade has shown that training on 'action video games' produces learning that transfers well beyond the training task. This has led to substantial interest among those interested in rehabilitation, for instance, after stroke or to treat amblyopia, or training for various precision-demanding jobs, for instance, endoscopic surgery or piloting unmanned aerial drones. Although the predominant focus of the field has been on outlining the breadth of possible action-game-related enhancements, recent work has concentrated on uncovering the mechanisms that underlie these changes, an important first step towards the goal of designing and using video games for more definite purposes. Game playing may not convey an immediate advantage on new tasks (increased performance from the very first trial), but rather the true effect of action video game playing may be to enhance the ability to learn new tasks. Such a mechanism may serve as a signature of training regimens that are likely to produce transfer of learning. Copyright © 2012 Elsevier Ltd. All rights reserved.

Scalable Video Coding with Interlayer Signal Decorrelation Techniques

Directory of Open Access Journals (Sweden)

Yang Wenxian

2007-01-01

Full Text Available Scalability is one of the essential requirements in the compression of visual data for present-day multimedia communications and storage. The basic building block for providing the spatial scalability in the scalable video coding (SVC standard is the well-known Laplacian pyramid (LP. An LP achieves the multiscale representation of the video as a base-layer signal at lower resolution together with several enhancement-layer signals at successive higher resolutions. In this paper, we propose to improve the coding performance of the enhancement layers through efficient interlayer decorrelation techniques. We first show that, with nonbiorthogonal upsampling and downsampling filters, the base layer and the enhancement layers are correlated. We investigate two structures to reduce this correlation. The first structure updates the base-layer signal by subtracting from it the low-frequency component of the enhancement layer signal. The second structure modifies the prediction in order that the low-frequency component in the new enhancement layer is diminished. The second structure is integrated in the JSVM 4.0 codec with suitable modifications in the prediction modes. Experimental results with some standard test sequences demonstrate coding gains up to 1 dB for I pictures and up to 0.7 dB for both I and P pictures.

Silole-Based Red Fluorescent Organic Dots for Bright Two-Photon Fluorescence In vitro Cell and In vivo Blood Vessel Imaging.

Science.gov (United States)

Chen, Bin; Feng, Guangxue; He, Bairong; Goh, Chiching; Xu, Shidang; Ramos-Ortiz, Gabriel; Aparicio-Ixta, Laura; Zhou, Jian; Ng, Laiguan; Zhao, Zujin; Liu, Bin; Tang, Ben Zhong

2016-02-10

Robust luminescent dyes with efficient two-photon fluorescence are highly desirable for biological imaging applications, but those suitable for organic dots fabrication are still rare because of aggregation-caused quenching. In this work, a red fluorescent silole, 2,5-bis[5-(dimesitylboranyl)thiophen-2-yl]-1-methyl-1,3,4-triphenylsilole ((MesB)2 DTTPS), is synthesized and characterized. (MesB)2 DTTPS exhibits enhanced fluorescence efficiency in nanoaggregates, indicative of aggregation-enhanced emission (AEE). The organic dots fabricated by encapsulating (MesB)2 DTTPS within lipid-PEG show red fluorescence peaking at 598 nm and a high fluorescence quantum yield of 32%. Upon excitation at 820 nm, the dots show a large two-photon absorption cross section of 3.43 × 10(5) GM, which yields a two-photon action cross section of 1.09 × 10(5) GM. These (MesB)2 DTTPS dots show good biocompatibility and are successfully applied to one-photon and two-photon fluorescence imaging of MCF-7 cells and two-photon in vivo visualization of the blood vascular of mouse muscle in a high-contrast and noninvasive manner. Moreover, the 3D blood vasculature located at the mouse ear skin with a depth of over 100 μm can also be visualized clearly, providing the spatiotemporal information about the whole blood vascular network. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Engineering and Characterization of a Superfolder Green Fluorescent Protein

International Nuclear Information System (INIS)

Pedelacq, J.; Cabantous, S.; Tran, T.; Terwilliger, T.; Waldo, G.

2006-01-01

Existing variants of green fluorescent protein (GFP) often misfold when expressed as fusions with other proteins. We have generated a robustly folded version of GFP, called 'superfolder' GFP, that folds well even when fused to poorly folded polypeptides. Compared to 'folding reporter' GFP, a folding-enhanced GFP containing the 'cycle-3' mutations and the 'enhanced GFP' mutations F64L and S65T, superfolder GFP shows improved tolerance of circular permutation, greater resistance to chemical denaturants and improved folding kinetics. The fluorescence of Escherichia coli cells expressing each of eighteen proteins from Pyrobaculum aerophilum as fusions with superfolder GFP was proportional to total protein expression. In contrast, fluorescence of folding reporter GFP fusion proteins was strongly correlated with the productive folding yield of the passenger protein. X-ray crystallographic structural analyses helped explain the enhanced folding of superfolder GFP relative to folding reporter GFP

Playing a first-person shooter video game induces neuroplastic change.

Science.gov (United States)

Wu, Sijing; Cheng, Cho Kin; Feng, Jing; D'Angelo, Lisa; Alain, Claude; Spence, Ian

2012-06-01

Playing a first-person shooter (FPS) video game alters the neural processes that support spatial selective attention. Our experiment establishes a causal relationship between playing an FPS game and neuroplastic change. Twenty-five participants completed an attentional visual field task while we measured ERPs before and after playing an FPS video game for a cumulative total of 10 hr. Early visual ERPs sensitive to bottom-up attentional processes were little affected by video game playing for only 10 hr. However, participants who played the FPS video game and also showed the greatest improvement on the attentional visual field task displayed increased amplitudes in the later visual ERPs. These potentials are thought to index top-down enhancement of spatial selective attention via increased inhibition of distractors. Individual variations in learning were observed, and these differences show that not all video game players benefit equally, either behaviorally or in terms of neural change.

Solid state video cameras

CERN Document Server

Cristol, Y

2013-01-01

Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.

Influence of fluorescence of Eu(dbm)3phen doped films by gold nanorods

International Nuclear Information System (INIS)

Wang, Qingru; Shi, Qiang; Li, Shuhong; Zhang, Dong; Wang, Wenjun

2016-01-01

The gold nanorods (AuNRs) were precipitated on Eu(dbm) 3 phen doped films by different spin rates. The plasmonic enhancement and quenching effects of gold nanorods on the fluorescence of Eu(dbm) 3 phen were both demonstrated. The enhancement on the fluorescence is sensitive to the distribution of the AuNRs. Both fluorescence enhancement mechanisms, i.e. increase of the intense absorption of ligands and increase of quantum efficiency, promote the 20 fold enhancement, at which the excitation wavelength red-shifts from 362 nm to 372 nm. Higher absorption of ligands in the complex due to the AuNRs caused the bathochromic shift of excitation peak. The quenching factor at 612 nm reached to 0.47.

A Practical Strategy for Teaching a Child with Autism to Attend to and Imitate a Portable Video Model

Science.gov (United States)

Plavnick, Joshua B.

2012-01-01

Video modeling is an effective and efficient methodology for teaching new skills to individuals with autism. New technology may enhance video modeling as smartphones or tablet computers allow for portable video displays. However, the reduced screen size may decrease the likelihood of attending to the video model for some children. The present…

Fast optically sectioned fluorescence HiLo endomicroscopy

Science.gov (United States)

Ford, Tim N.; Lim, Daryl; Mertz, Jerome

2012-02-01

We describe a nonscanning, fiber bundle endomicroscope that performs optically sectioned fluorescence imaging with fast frame rates and real-time processing. Our sectioning technique is based on HiLo imaging, wherein two widefield images are acquired under uniform and structured illumination and numerically processed to reject out-of-focus background. This work is an improvement upon an earlier demonstration of widefield optical sectioning through a flexible fiber bundle. The improved device features lateral and axial resolutions of 2.6 and 17 μm, respectively, a net frame rate of 9.5 Hz obtained by real-time image processing with a graphics processing unit (GPU) and significantly reduced motion artifacts obtained by the use of a double-shutter camera. We demonstrate the performance of our system with optically sectioned images and videos of a fluorescently labeled chorioallantoic membrane (CAM) in the developing G. gallus embryo. HiLo endomicroscopy is a candidate technique for low-cost, high-speed clinical optical biopsies.

Use of a Novel Rover-mounted Fluorescence Imager and Fluorescent Probes to Detect Biological Material in the Atacama Desert in Daylight

Science.gov (United States)

Weinstein, S.; Pane, D.; Warren-Rhodes, K.; Cockell, C.; Ernst, L. A.; Minkley, E.; Fisher, G.; Emani, S.; Wettergreen, D. S.; Wagner, M.

2005-01-01

We have developed an imaging system, the Fluorescence Imager (FI), for detecting fluorescence signals from sparse microorganisms and biofilms during autonomous rover exploration. The fluorescence signals arise both from naturally occurring chromophores, such as chlorophyll of cyanobacteria and lichens, and from fluorescent probes applied to soil and rocks. Daylight imaging has been accomplished by a novel use of a high-powered flashlamp synchronized to a CCD camera. The fluorescent probes are cell permanent stains that have extremely low intrinsic fluorescence (quantum yields less than 0.01) and a large fluorescence enhancement (quantum yields greater than 0.4) when bound to the target. Each probe specifically targets either carbohydrates, proteins, nucleic acids or membrane lipids, the four classes of macromolecules found in terrestrial life. The intent of the probes is to interrogate the environment for surface and endolithic life forms.

Enhanced fluorescence of Tb(III), Dy(III) perchlorate by salicylic acid in bis(benzoylmethyl) sulfoxide complexes and luminescence mechanism

International Nuclear Information System (INIS)

Li Wenxian; Zheng Yushan; Sun Xiaojun; Chai Wenjuan; Ren Tie; Shi Xiaoyan

2010-01-01

Two novel ternary rare earth perchlorate complexes had been synthesized by using bis(benzoylmethyl) sulfoxide as first ligand (L=C 6 H 5 COCH 2 SOCH 2 COC 6 H 5 ), salicylic acid as second ligand (L ' =C 6 H 4 OHCOO - ). The compounds were characterized by elemental analysis, TG-DSC and molar conductivities in DMF solution. The composition was suggested as [REL 5 L'](ClO 4 ) 2 .nH 2 O (RE=Tb, Dy; n=6, 8 ). Based on IR, 1 HNMR and UV spectra, it showed that the first ligand, bis(benzoylmethyl) sulfoxide (L), bonded with Tb(III), Dy(III) ions by the oxygen atom of sulfinyl group. The second ligand, salicylic acid group (L'), not only bonded with RE(III) ions by one oxygen atom of carboxyl group but also bonded with RE(III) ions by oxygen atom of phenolic hydroxyl group. In bis(benzoylmethyl) sulfoxide system, fluorescent spectra of the complexes showed that the luminescence of Tb(III), Dy(III) ions was enhanced by the second ligand salicylic acid. The ternary complexes had stronger fluorescence than the binary ones where only bis(benzoylmethyl) sulfoxide acted as ligand. Phosphorescent spectra of the two ligands indicated that the coordination of salicylic acid resulted in the matching extent increasing between the triplet state of ligand and excited state of the rare earths. The relationship between fluorescence lifetime and fluorescence intensity was also discussed.

Efficient Power Allocation for Video over Superposition Coding

KAUST Repository

Lau, Chun Pong

2013-03-01

In this paper we consider a wireless multimedia system by mapping scalable video coded (SVC) bit stream upon superposition coded (SPC) signals, referred to as (SVC-SPC) architecture. Empirical experiments using a software-defined radio(SDR) emulator are conducted to gain a better understanding of its efficiency, specifically, the impact of the received signal due to different power allocation ratios. Our experimental results show that to maintain high video quality, the power allocated to the base layer should be approximately four times higher than the power allocated to the enhancement layer.

Bring It to the Pitch: Combining Video and Movement Data to Enhance Team Sport Analysis.

Science.gov (United States)

Stein, Manuel; Janetzko, Halldor; Lamprecht, Andreas; Breitkreutz, Thorsten; Zimmermann, Philipp; Goldlucke, Bastian; Schreck, Tobias; Andrienko, Gennady; Grossniklaus, Michael; Keim, Daniel A

2018-01-01

Analysts in professional team sport regularly perform analysis to gain strategic and tactical insights into player and team behavior. Goals of team sport analysis regularly include identification of weaknesses of opposing teams, or assessing performance and improvement potential of a coached team. Current analysis workflows are typically based on the analysis of team videos. Also, analysts can rely on techniques from Information Visualization, to depict e.g., player or ball trajectories. However, video analysis is typically a time-consuming process, where the analyst needs to memorize and annotate scenes. In contrast, visualization typically relies on an abstract data model, often using abstract visual mappings, and is not directly linked to the observed movement context anymore. We propose a visual analytics system that tightly integrates team sport video recordings with abstract visualization of underlying trajectory data. We apply appropriate computer vision techniques to extract trajectory data from video input. Furthermore, we apply advanced trajectory and movement analysis techniques to derive relevant team sport analytic measures for region, event and player analysis in the case of soccer analysis. Our system seamlessly integrates video and visualization modalities, enabling analysts to draw on the advantages of both analysis forms. Several expert studies conducted with team sport analysts indicate the effectiveness of our integrated approach.

Augmenting real-time video with virtual models for enhanced visualization for simulation, teaching, training and guidance

Science.gov (United States)

Potter, Michael; Bensch, Alexander; Dawson-Elli, Alexander; Linte, Cristian A.

2015-03-01

In minimally invasive surgical interventions direct visualization of the target area is often not available. Instead, clinicians rely on images from various sources, along with surgical navigation systems for guidance. These spatial localization and tracking systems function much like the Global Positioning Systems (GPS) that we are all well familiar with. In this work we demonstrate how the video feed from a typical camera, which could mimic a laparoscopic or endoscopic camera used during an interventional procedure, can be used to identify the pose of the camera with respect to the viewed scene and augment the video feed with computer-generated information, such as rendering of internal anatomy not visible beyond the imaged surface, resulting in a simple augmented reality environment. This paper describes the software and hardware environment and methodology for augmenting the real world with virtual models extracted from medical images to provide enhanced visualization beyond the surface view achieved using traditional imaging. Following intrinsic and extrinsic camera calibration, the technique was implemented and demonstrated using a LEGO structure phantom, as well as a 3D-printed patient-specific left atrial phantom. We assessed the quality of the overlay according to fiducial localization, fiducial registration, and target registration errors, as well as the overlay offset error. Using the software extensions we developed in conjunction with common webcams it is possible to achieve tracking accuracy comparable to that seen with significantly more expensive hardware, leading to target registration errors on the order of 2 mm.

Progress in video immersion using Panospheric imaging

Science.gov (United States)

Bogner, Stephen L.; Southwell, David T.; Penzes, Steven G.; Brosinsky, Chris A.; Anderson, Ron; Hanna, Doug M.

1998-09-01

Having demonstrated significant technical and marketplace advantages over other modalities for video immersion, PanosphericTM Imaging (PI) continues to evolve rapidly. This paper reports on progress achieved since AeroSense 97. The first practical field deployment of the technology occurred in June-August 1997 during the NASA-CMU 'Atacama Desert Trek' activity, where the Nomad mobile robot was teleoperated via immersive PanosphericTM imagery from a distance of several thousand kilometers. Research using teleoperated vehicles at DRES has also verified the exceptional utility of the PI technology for achieving high levels of situational awareness, operator confidence, and mission effectiveness. Important performance enhancements have been achieved with the completion of the 4th Generation PI DSP-based array processor system. The system is now able to provide dynamic full video-rate generation of spatial and computational transformations, resulting in a programmable and fully interactive immersive video telepresence. A new multi- CCD camera architecture has been created to exploit the bandwidth of this processor, yielding a well-matched PI system with greatly improved resolution. While the initial commercial application for this technology is expected to be video tele- conferencing, it also appears to have excellent potential for application in the 'Immersive Cockpit' concept. Additional progress is reported in the areas of Long Wave Infrared PI Imaging, Stereo PI concepts, PI based Video-Servoing concepts, PI based Video Navigation concepts, and Foveation concepts (to merge localized high-resolution views with immersive views).

Video microblogging

DEFF Research Database (Denmark)

Bornoe, Nis; Barkhuus, Louise

2010-01-01

Microblogging is a recently popular phenomenon and with the increasing trend for video cameras to be built into mobile phones, a new type of microblogging has entered the arena of electronic communication: video microblogging. In this study we examine video microblogging, which is the broadcasting...... of short videos. A series of semi-structured interviews offers an understanding of why and how video microblogging is used and what the users post and broadcast....

The impact of recreational video game play on children's and adolescents' cognition.

Science.gov (United States)

Blumberg, Fran C; Altschuler, Elizabeth A; Almonte, Debby E; Mileaf, Maxwell I

2013-01-01

Current empirical findings show linkages between recreational video game play and enhanced cognitive skills, primarily among young adults. However, consideration of this linkage among children and adolescents is sparse. Thus, discussions about facilitating transfer of cognitive skills from video game play to academic tasks among children and adolescents remains largely uninformed by research. To inform this discussion, we review available research concerning the cognitive benefits of video game play among children and adolescents and their impressions of video games as learning tools as these impressions may impact their application of cognitive skills used during game play to academic tasks. Copyright © 2013 Wiley Periodicals, Inc., A Wiley Company.

Online videos to promote sun safety: results of a contest

Directory of Open Access Journals (Sweden)

Annelise Lorelei Dawson

2011-06-01

Full Text Available Seventy-percent of Americans search health information online, half of whom access medical content on social media websites.  In spite of this broad usage, the medical community underutilizes social media to distribute preventive health information.  This project aimed to highlight the promise of social media for delivering skin cancer prevention messaging by hosting and quantifying the impact of an online video contest. In 2010 and 2011, we solicited video submissions and searched existing YouTube videos.  Three finalists were selected and ranked. Winners were announced at national dermatology meetings and publicized via a contest website. Afterwards, YouTube view counts were monitored.  No increase in video viewing frequency was observed following the 2010 or 2011 contest.  This contest successfully identified exemplary online sun safety videos; however, increased viewership remains to be seen.  Social media offers a promising outlet for preventive health messaging. Future efforts must explore strategies for enhancing viewership of online content.

Designing Serious Video Games for Health Behavior Change: Current Status and Future Directions

OpenAIRE

Thompson, Debbe

2012-01-01

Serious video games for health are designed to entertain while changing a specific health behavior. This article identifies behavioral principles that can guide the development of serious video games focused on changing a variety of health behaviors, including those attempting to decrease risk of obesity and type 2 diabetes. Guidelines discussed include how to develop video games that provide a solid foundation for behavior change by enhancing a player’s knowledge and skill, ways in which per...

Innovative molecular-based fluorescent nanoparticles for multicolor single particle tracking in cells

International Nuclear Information System (INIS)

Daniel, Jonathan; Blanchard-Desce, Mireille; Godin, Antoine G; Palayret, Matthieu; Lounis, Brahim; Cognet, Laurent

2016-01-01

Based on an original molecular-based design, we present bright and photostable fluorescent organic nanoparticles (FONs) showing excellent colloidal stability in various aqueous environments. Complementary near-infrared emitting and green emitting FONs were prepared using a simple, fast and robust protocol. Both types of FONs could be simultaneously imaged at the single-particle level in solution as well as in biological environments using a monochromatic excitation and a dual-color fluorescence microscope. No evidence of acute cytotoxicity was found upon incubation of live cells with mixed solutions of FONs, and both types of nanoparticles were found internalized in the cells where their motion could be simultaneously tracked at video-rate up to minutes. These fluorescent organic nanoparticles open a novel non-toxic alternative to existing nanoparticles for imaging biological structures, compatible with live-cell experiments and specially fitted for multicolor single particle tracking. (paper)

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.

CameraCast: flexible access to remote video sensors

Science.gov (United States)

Kong, Jiantao; Ganev, Ivan; Schwan, Karsten; Widener, Patrick

2007-01-01

New applications like remote surveillance and online environmental or traffic monitoring are making it increasingly important to provide flexible and protected access to remote video sensor devices. Current systems use application-level codes like web-based solutions to provide such access. This requires adherence to user-level APIs provided by such services, access to remote video information through given application-specific service and server topologies, and that the data being captured and distributed is manipulated by third party service codes. CameraCast is a simple, easily used system-level solution to remote video access. It provides a logical device API so that an application can identically operate on local vs. remote video sensor devices, using its own service and server topologies. In addition, the application can take advantage of API enhancements to protect remote video information, using a capability-based model for differential data protection that offers fine grain control over the information made available to specific codes or machines, thereby limiting their ability to violate privacy or security constraints. Experimental evaluations of CameraCast show that the performance of accessing remote video information approximates that of accesses to local devices, given sufficient networking resources. High performance is also attained when protection restrictions are enforced, due to an efficient kernel-level realization of differential data protection.

Examination of Primary and Secondary School Teachers' Aspects towards Educational Use of Video Sharing Websites

Science.gov (United States)

Usta, Ertugrul; Atun, Handan

2017-01-01

Daily use of video has increased by televisions, but lately people have been using video sharing websites most frequently. This extended use of video sharing websites has emerged a new era for education; teachers and learners can use them to enhance learning in education. Hence, the purpose of this study is to examine primary and secondary school…

DNA-Based Self-Assembly of Fluorescent Nanodiamonds.

Science.gov (United States)

Zhang, Tao; Neumann, Andre; Lindlau, Jessica; Wu, Yuzhou; Pramanik, Goutam; Naydenov, Boris; Jelezko, Fedor; Schüder, Florian; Huber, Sebastian; Huber, Marinus; Stehr, Florian; Högele, Alexander; Weil, Tanja; Liedl, Tim

2015-08-12

As a step toward deterministic and scalable assembly of ordered spin arrays we here demonstrate a bottom-up approach to position fluorescent nanodiamonds (NDs) with nanometer precision on DNA origami structures. We have realized a reliable and broadly applicable surface modification strategy that results in DNA-functionalized and perfectly dispersed NDs that were then self-assembled in predefined geometries. With optical studies we show that the fluorescence properties of the nitrogen-vacancy color centers in NDs are preserved during surface modification and DNA assembly. As this method allows the nanoscale arrangement of fluorescent NDs together with other optically active components in complex geometries, applications based on self-assembled spin lattices or plasmon-enhanced spin sensors as well as improved fluorescent labeling for bioimaging could be envisioned.

Fluorescence enhancement upon G-quadruplex folding: synthesis, structure, and biophysical characterization of a dansyl/cyclodextrin-tagged thrombin binding aptamer.

Science.gov (United States)

De Tito, Stefano; Morvan, François; Meyer, Albert; Vasseur, Jean-Jacques; Cummaro, Annunziata; Petraccone, Luigi; Pagano, Bruno; Novellino, Ettore; Randazzo, Antonio; Giancola, Concetta; Montesarchio, Daniela

2013-11-20

A novel fluorescent thrombin binding aptamer (TBA), conjugated with the environmentally sensitive dansyl probe at the 3'-end and a β-cyclodextrin residue at the 5'-end, has been efficiently synthesized exploiting Cu(I)-catalyzed azide-alkyne cycloaddition procedures. Its conformation and stability in solution have been studied by an integrated approach, combining in-depth NMR, CD, fluorescence, and DSC studies. ITC measurements have allowed us to analyze in detail its interaction with human thrombin. All the collected data show that this bis-conjugated aptamer fully retains its G-quadruplex formation ability and thrombin recognition properties, with the terminal appendages only marginally interfering with the conformational behavior of TBA. Folding of this modified aptamer into the chairlike, antiparallel G-quadruplex structure, promoted by K(+) and/or thrombin binding, typical of TBA, is associated with a net fluorescence enhancement, due to encapsulation of dansyl, attached at the 3'-end, into the apolar cavity of the β-cyclodextrin at the 5'-end. Overall, the structural characterization of this novel, bis-conjugated TBA fully demonstrates its potential as a diagnostic tool for thrombin recognition, also providing a useful basis for the design of suitable aptamer-based devices for theranostic applications, allowing simultaneously both detection and inhibition or modulation of the thrombin activity.

Dashboard Videos

Science.gov (United States)

Gleue, Alan D.; Depcik, Chris; Peltier, Ted

2012-01-01

Last school year, I had a web link emailed to me entitled "A Dashboard Physics Lesson." The link, created and posted by Dale Basier on his "Lab Out Loud" blog, illustrates video of a car's speedometer synchronized with video of the road. These two separate video streams are compiled into one video that students can watch and analyze. After seeing…

Pediatric Obesity: Is There Room for Active Video Games in Prevention or Management?

Science.gov (United States)

Thivel, David; OʼMalley, Grace

2016-01-01

Children and adolescents spend a considerable amount of time engaged in sedentary behaviors that have been shown to favor weight gain and impaired physical fitness. Active video games have been proposed to increase physical activity levels. Although active video games may offer an interesting alternative to reducing sedentary time for children, the present commentary aimed to determine whether there is adequate evidence that compared active video gaming to real-life play and exercise. Given the dearth of data, it is not possible at present to support the use of active video games as substitutes for traditional forms of active play and health-enhancing physical activity. Further research should be encouraged and therapists should not consider active video games exclusively for intervention in children with obesity.

Privacy information management for video surveillance

Science.gov (United States)

Luo, Ying; Cheung, Sen-ching S.

2013-05-01

The widespread deployment of surveillance cameras has raised serious privacy concerns. Many privacy-enhancing schemes have been proposed to automatically redact images of trusted individuals in the surveillance video. To identify these individuals for protection, the most reliable approach is to use biometric signals such as iris patterns as they are immutable and highly discriminative. In this paper, we propose a privacy data management system to be used in a privacy-aware video surveillance system. The privacy status of a subject is anonymously determined based on her iris pattern. For a trusted subject, the surveillance video is redacted and the original imagery is considered to be the privacy information. Our proposed system allows a subject to access her privacy information via the same biometric signal for privacy status determination. Two secure protocols, one for privacy information encryption and the other for privacy information retrieval are proposed. Error control coding is used to cope with the variability in iris patterns and efficient implementation is achieved using surrogate data records. Experimental results on a public iris biometric database demonstrate the validity of our framework.