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Results 301 - 350 of 828
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Tymecki Łukasz - - 2011
Integration of two light emitting diodes allows construction of a fluorometric paired emitter detector diode (FPEDD)--a compact optoelectronic device useful as a complete flow-through fluorescence detector.
Helander Michael G - - 2010
A fluorinated phenoxy boron subphthalocyanine (BsubPc) is shown to function as a fluorescent dopant emitter in small molecule organic light emitting diodes (OLEDs). Narrow electroluminescence (EL) emission with a full width at half-maximum of ∼30 nm was observed regardless of the host used, indicating that this narrow EL is intrinsic ...
Gruszecki Wieslaw I - - 2011
Excitation of the major photosynthetic antenna complex of plants, LHCII, with blue light (470nm) provides an advantage to plants, as it gives rise to chlorophyll a fluorescence lifetimes shorter than with excitation with red light (635nm). This difference is particularly pronounced in fluorescence emission wavelengths longer than 715nm. Illumination of ...
Branchini Bruce R - - 2010
Bioluminescence and bioluminescence resonance energy transfer (BRET) are two naturally occurring light emission phenomena that have been adapted to a wide variety of important research applications including in vivo imaging and enzyme assays. The luciferase enzyme from the North American firefly, which produces yellow-green light, is a key component of ...
Sinha Sujeet Kumar - - 2010
The neural encoding of speech sound begins in the auditory nerve and travels to the auditory brainstem. Non speech stimuli such as click or tone bursts stimulus are used to check the auditory neural integrity routinely. Recently Speech evoked Auditory Brainstem measures (ABR) are being used as a tool to ...
Iriel Analía - - 2010
Flower fluorescence has been previously proposed as a potential visual signal to attract pollinators. In this work, this point was addressed by quantitatively measuring the fluorescence quantum yield (Φ(f)) for flowers of Bellis perennis (white, yellow, pink, and purple), Ornithogalum thyrsoides (petals and ovaries), Limonium sinuatum (white and yellow), Lampranthus ...
Buck James W - - 2010
The effects of light on urediniospore germination and germ tube elongation was studied with eight species of rust fungi that infect ornamental plants or row crops. Exposure of six species of fungi to cool white fluorescent light at 400 or 600 micromol s(-1) m(-2) for 24 h significantly reduced germination ...
Morishita Masatoshi - - 2010
We studied the sliding friction between an adhesive gel sheet and a glass substrate. In this system, the probability distribution of the force drop obeys a power law similar to that found in earthquakes and granular systems. We observed the motion of the slip regions at the frictional interfaces and ...
Jochum Florian D - - 2010
In this communication, the synthesis and characterization of thermo- and light responsive block copolymers is reported. PEO-b-PNIPAM polymers with azobenzene moieties were prepared and analyzed by turbidimetry, fluorescence, NMR and DLS measurements. A temperature controlled reversible formation as well as a light induced disruption and reformation of micellar structures in ...
Zorn Matthias - - 2010
ZnO nanorods were functionalized with new block copolymers containing a hole transporting moiety in one block and a dye and an anchor system in the second block. After functionalization, the ZnO nanorods are well dispersible in organic media and the fluorescence of the dye is quenched. Kelvin probe force microscopy ...
Asztalos Emese - - 2010
The induction (sudden dark-to-light transition) of fluorescence of photosynthetic bacteria has proved to be sensitive tool for early detection of mercury (Hg(2+)) contamination of the culture medium. The major characteristics of the induction (dark, variable and maximum fluorescence levels together with rise time) offer an easier, faster and more informative ...
Lin Shi-Wei - - 2010
A simple method is proposed for modulating the excitation light used for multi-color fluorescence detection in a single capillary electrophoresis (CE) channel. In the proposed approach, a low-cost commercial liquid crystal device (LCD) projector with digitally-modulated LCD switches is used to provide the illumination light source and the fluorescence emitted ...
Matsumi Yutaka - - 2010
We report on the development of a low-cost and compact instrument for quantifying atmospheric NO(2) concentrations by detecting NO(2) fluorescence using a commercial light-emitting diode around 435nm as a fluorescence excitation light source. The minimum detectable limit of the NO(2) instrument developed has been estimated to be 9.8 parts per ...
Matsumi Yutaka - - 2010
We report on the development of a low-cost and compact instrument for quantifying atmospheric NO(2) concentrations by detecting NO(2) fluorescence using a commercial light-emitting diode around 435 nm as a fluorescence excitation light source. The minimum detectable limit of the NO(2) instrument developed has been estimated to be 9.8 parts ...
Vardapetyan H R - - 2010
In the present work the hypericin interaction with hemoglobin was studied by absorption and fluorescence spectroscopy both under incubation in dark and visible light exposure. An absorption reduction in Soret band of hemoglobin (407 nm) was revealed under the photodynamic influence and incubation in dark with hypericin that had hypericin ...
Febvay Sébastien S Department of Cardiology, Howard Hughes Medical Institute, Manton Center for Orphan Disease, Children's Hospital Boston, Boston, Massachusetts 02115, - - 2010
Nanoparticle (NP)-mediated drug delivery typically relies on cargo release to occur passively or in response to environmental stimuli. Here we present a delivery method based on light-activated disruption of intracellular vesicles after internalization of biofunctionalized mesoporous silica nanoparticles loaded with cargo. This method combines the power of targeted delivery with ...
Goel Atul - - 2010
A novel series of thermally stable yellow light emitting fluoranthenes with an amine donor and a nitrile acceptor was prepared from a ketene-S,S-acetal under mild conditions without using an organometal catalyst. The organic light emitting device of yellow fluoranthene 10b exhibited substantially low turn-on voltage (2.6 V) and maximum brightness ...
Ozawa Mio - - 2010
AIM: Current recommendations for illumination in the NICU state that procedure light should be controlled with a rheostat to protect infants from high illumination. However, overhead fluorescent lights without a dimmer switch are still used in Japan. The aim of this study was to assess the effects of three different ...
Gotoh Eiji - - 2010
The mechanism of post-illumination chlorophyll fluorescence transient (PIFT) was investigated in Arabidopsis. PIFT was detected in the wild type after illumination with low light. In the fba3-2 (fructose-1,6-bisphosphate aldolase) mutant, in which PIFT is enhanced, strong light also induced PIFT. PIFT was suppressed not only in the triose phosphate/phosphate translocator ...
Keirstead Amy E - - 2010
A molecular "hexad" in which five bis(phenylethynyl)anthracene (BPEA) fluorophores and a dithienylethene photochrome are organized by a central hexaphenylbenzene unit has been prepared. Singlet-singlet energy transfer among the BPEA units occurs on the 0.4 and 60 ps time scales, and when the dithienylethene is in the open form, the BPEA ...
Kolarik Andrew J - - 2010
The spectral resolution of the binaural system was measured using a tone-detection task in a binaural analog of the notched-noise technique. Three listeners performed 2-interval, 2-alternative, forced choice tasks with a 500-ms out-of-phase signal within 500 ms of broadband masking noise consisting of an "outer" band of either interaurally uncorrelated ...
Quercioli Valentina - - 2010
New probes for kinetic intracellular measurements in the millisecond range are desirable to monitor protein biochemical dynamics essential for catalysis, allosteric regulation, and signaling. Good candidates to this aim are the photoswitchable mutants of the green fluorescent protein, whose anionic fluorescence, primed by blue light, is markedly enhanced under an ...
Stehfest Katja - - 2010
Channelrhodopsins (ChRs) of green algae such as Chlamydomonas are used as neuroscience tools to specifically depolarize cells with light. A crude model of the ChR2 photocycle has been recently established, but details of the photoreactions are widely unknown. Here, we present the photoreactions of a slow-cycling ChR2 mutant (step function ...
Vohra Varun - - 2010
Nanosized zeolite L crystals containing about 550 strongly luminescent acceptor molecules have been modified by grafting a conjugated oligomer on their external surface. The 25 nm sized crystals have consequently been embedded in polymeric nanofibers obtained by electrospinning. The fluorescent molecule grafted on the external surface allows addressing the guests ...
Strasser Reto J - - 2010
A new instrument (M-PEA), which measures simultaneously kinetics of prompt fluorescence (PF), delayed fluorescence (DF) and modulated light reflection at 820nm (MR), was used to screen dark-adapted leaves of the resurrection plant Haberlea rhodopensis during their progressive drying, down to 1% relative water content (RWC), and after their re-watering. This ...
Rehberg Markus - - 2010
In conventional fluorescence or confocal microscopy, emitted light is generated not only in the focal plane but also above and below. The situation is different in multiphoton-induced fluorescence and multiphoton-induced higher harmonic generation. Here, restriction of signal generation to a single focal point permits that all emitted photons can contribute ...
Tian Yu - - 2010
Phycobiliprotein fluorescent labels are playing an increasingly important role in bioanalysis. They are also being used more and more frequently as light-harvesting materials for energy research. It is therefore critical to study the working conditions of these fluorescent dyes. Allophycocyanin (APC) belongs to a group of phycobiliproteins and features red ...
Reck-Peterson Samara L - - 2010
When performing analysis using total internal reflection fluorescence microscopy (TIRFM), fluorescence intensity depends linearly on excitation intensity, until the dye spends most of its time in the excited state (i.e., saturation is reached). How much light is seen by the dyes in the sample depends not only on the amount ...
L? Xiaodan - - 2010
White light emitting semiconductor nanocrystals (NCs) have been successfully synthesized from 8-hydroxyquinoline-5-sulfonic acid (HQS) decorated manganese doped ZnS NCs through fine tuning the surface-coordination emission and dopant emission of the NC host. The HQS functionalized manganese doped ZnS NCs (QS-ZnS:Mn), with a cubic crystal structure, have the same diameter of ...
Lee Hsien-Ming HM Department of Chemistry, Division of Medicinal Chemistry and Natural Products, University of North Carolina, Chapel Hill, North Carolina 27599, - - 2010
Light-regulatable compounds are finding increasing utility as spatial and temporal probes of biological behavior. An independent measure of successful light-induced structural change is possible when alteration (e.g., activation, deactivation, etc.) of the bioprobe can be directly linked to a fluorescent readout. We have identified a series of photolabile fluorescently quenched ...
Jensen James S - - 2010
Resveratrol and resveratrol glucoside (piceid) were evaluated in a preformulation stability study. An HPLC assay was used for the analysis of stressed/reference samples. Samples of solid, crystalline material were held under the following conditions: 40 degrees C/75% RH (both open and protected), ambient fluorescent light (open), 70 degrees C (open), ...
Wang Jiwei - - 2010
A new multiphoton upconversion process for rare earth oxide powders is reported, using infrared laser diodes. In vacuum, multiphoton excitation produces intense upconversion emission in the visible spectral range, and Tm(2)O(3) or Yb(2)O(3) achieves pure white upconversion using 808 or 975 nm excitation, respectively.
Iriel Analia - - 2010
A quantitative evaluation of the light emerging from intact petals of Rhododendron indicum flowers of different colours was performed. Reflectance and fluorescence emission were analyzed in detail. The fluorescence quantum yield of petals was determined on entire flowers. The obtained values varied from 7.6 x 10(-5) to 6.3 x 10(-4) ...
Nilkens Manuela - - 2010
The induction and relaxation of non-photochemical quenching (NPQ) under steady-state conditions, i.e. during up to 90min of illumination at saturating light intensities, was studied in Arabidopsis thaliana. Besides the well-characterized fast qE and the very slow qI component of NPQ, the analysis of the NPQ dynamics identified a zeaxanthin (Zx) ...
Motoyoshi Isamu - - 2010
The present study analyzes the effect of local pairwise orientation relations on the perception of textural structure. We have employed a new class of stochastic stimuli comprised of paired Gabor patches with a particular orientation difference (θ) and relative angular position (ϕ). We measured the threshold proportion of signal pairs ...
Pitts Michael A MA Department of Neurosciences, University of California San Diego, La Jolla, CA 92093-0608, USA. - - 2010
Anatomically "early" visual areas including striate cortex (V1) are known to play a role in the resolution of binocular rivalry. However, the time course of such activity and its relationship with subjective perception are unclear. The present study used an intermittent stimulation design to measure event-related potentials (ERPs) associated with ...
Pircher M - - 2010
In this study we use our previously introduced scanning laser ophthalmoscope (SLO) / transverse scanning optical coherence tomography (TS-OCT) instrument to investigate long term changes in cone photoreceptors. The instrument is capable to provide 3D information of the human cone photoreceptors with negligible eye motion artifacts due to an implemented ...
Bakos József - - 2010
Starting in 2009, certain types of incandescent light bulbs will be withdrawn from the market in the European Union and elsewhere. However, compact fluorescent lamps that are among the candidates to replace them produce intermediate frequency electric fields (EFs) much higher than any other device or appliance previously available to ...
Kuhn Walter - - 2010
The presence of acid-fast bacilli (AFB) in laboratories has traditionally been demonstrated using the fluorochrome method, which requires a fluorescent microscope or the Ziehl-Neelsen (ZN) method employing light microscopy. Low sensitivity of the ZN method and high costs of fluoroscopy make the need for a more effective means of diagnosis ...
Ferreira Zandoná A A Department of Preventive and Community Dentistry, Indiana University School of Dentistry, Indianapolis, IN, USA. - - 2010
The purpose of this study was to combine a standardized visually based system, the International Caries Detection and Assessment System (ICDAS), with a sensitive fluorescence-based system, quantitative light-induced fluorescence (QLF), to determine the ability to monitor caries lesion progression. This combination (QLF-I) has the potential to increase the sensitivity of ...
Xiao Bei - - 2010
Cortical responses to spatially discrete patches of achromatic luminance contrast can be altered by the presence of high-contrast, spatially remote "surrounds" and this achromatic "surround suppression" has been the subject of much recent research. However, the nature of long-range contrast normalization in chromatic signals has been less studied. Here we ...
Khuu Sieu K - - 2010
When a number of visual elements are presented briefly one after the other at two separate locations, mislocalization occurs with elements perceived "jumping" evenly across the space between locations. This is the visual saltation illusion. We investigated whether saltation occurs in three-dimensional (3D) space. In separate experiments, observers judged the ...
Lard Mercy - - 2010
A major problem when studying behavior and migration of small organisms is that many of the questions addressed for larger animals are not possible to formulate due to constraints on tracking smaller animals. In aquatic ecosystems, this problem is particularly problematic for zoo- and phytoplankton, since tracking devices are too ...
Mayinger B - - 2010
BACKGROUND AND STUDY AIMS: To compare the rate of detection of colorectal neoplastic lesions using the selective photosensitizer precursor hexaminolevulinate (HAL) combined with a new fluorescence video endoscope system against that of standard white light endoscopy, and secondarily, to evaluate the safety profile of HAL-induced fluorescence colonoscopy. PATIENTS AND METHODS: ...
Hampson Karen M - - 2010
Dynamic correction of monochromatic aberrations of the eye is known to affect the accommodation response to a step change in stimulus vergence. We used an adaptive optics system to determine how the temporal location of the correction affects the response. The system consists of a Shack-Hartmann sensor sampling at 20 ...
Dickinson J Edwin - - 2010
Adaptation to prevailing stimuli is a ubiquitous property of the visual system that optimizes its dynamic range. The perceived difference in orientation of successively presented lines of similar orientation is exaggerated and the perceived shape of an object is influenced by previously experienced shapes. Change in perceived shape is assumed ...
Freiberger Manuel - - 2010
Fluorescence tomography excites a fluorophore inside a sample by light sources on the surface. From boundary measurements of the fluorescent light, the distribution of the fluorophore is reconstructed. The optode placement determines the quality of the reconstructions in terms of, e.g., resolution and contrast-to-noise ratio. We address the adaptation of ...
Akimoto Takuo - - 2010
Fluorescence enhancement from a multilayered substrate fabricated with Ag and Al(2)O(3) was investigated using fluorescein, rhodamine B, Cy3, and Cy5 as fluorophores. The change in the fluorescence enhancement with Al(2)O(3) had two peaks and one valley in the range from 0 to 300 nm of Al(2)O(3) thickness, and such peaks ...
Colyer Ryan A - - 2010
We present a novel approach to high-throughput Fluorescence Correlation Spectroscopy (FCS) which enables us to obtain one order of magnitude improvement in acquisition time. Our approach utilizes a liquid crystal on silicon spatial light modulator to generate dynamically adjustable focal spots, and uses an eight-pixel monolithic single-photon avalanche photodiode array. ...
Lambrev Petar H - - 2010
Using novel specially designed instrumentation, fluorescence emission spectra were recorded from Arabidopsis (Arabidopsis thaliana) leaves during the induction period of dark to high-light adaptation in order to follow the spectral changes associated with the formation of nonphotochemical quenching. In addition to an overall decrease of photosystem II fluorescence (quenching) across ...
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