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Results 401 - 450 of 828
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Hui K N - - 2008
An innovative spectral conversion scheme for light emitting diodes using fluorescent microspheres has been demonstrated. An optimally mixed proportion of green and red fluorescent microspheres were coated onto a high-extraction-efficiency GaN micro-LED with emission centred at 470 nm. The microspheres self-assemble into ordered hexagonally arrays, forming regular and uniform coating ...
Jeon Byeong Wook - - 2008
ROP small G proteins function as molecular switches in diverse signaling processes. Here, we investigated signals that activate ROP2 in guard cells. In guard cells of Vicia faba expressing Arabidopsis thaliana constitutively active (CA) ROP2 fused to red fluorescent protein (RFP-CA-ROP2), fluorescence localized exclusively at the plasma membrane, whereas a ...
Filanoski Brian - - 2008
A novel optical signal element based on homogeneous bioluminescence resonance energy transfer (BRET) was developed for biomolecular detection. A fluorescent dye and alkaline phosphatase (AP) conjugate was used as a reporter and light-generation element for imaging detection platforms that use a CCD camera or CMOS chip-based devices. In the presence ...
Liu Xiaohan X Graduate school of Science and Technology, Niigata University, Niigata-shi, 950-2181, Japan. - - 2008
A VLC (Visible Light Communication) system using fluorescent lights has been developed for indoor guidance of the visually impaired. While it is relatively straightforward to provide generalized location information for a blind user, precise location information is much more difficult to determine. We propose that the effective data reception range ...
Baleizão Carlos - - 2008
This report reviews the thermally activated delayed fluorescence (TADF) displayed by fullerenes. From the analysis of the steady-state data, time-resolved data, or by a combination of both, it is possible to determine several important photophysical parameters of fullerenes. Herein we also cover the development of temperature and oxygen sensors based ...
García-González Martín J MJ Unidad de Coronarias, Servicio de Cardiología, Hospital Universitario de Canarias, La Laguna, Santa Cruz de Tenerife, - - 2008
Activation of the cellmediated immune system plays an important role in atherogenesis and in triggering the development of acute coronary syndrome. Neopterin, a biomarker of cellmediated immune system activity, is also a well-known biomarker of coronary artery disease. It is known that the occurrence of coronary heart disease events is ...
Ogasawara Shinzi - - 2008
We have developed a set of photochromic nucleobases (PCNs), which reversibly change the photochemical and physical properties such as fluorescence intensity upon cis-trans photoisomerization by the external light stimuli. PCNs showed very rapid and efficient reversible photoisomerization by illumination at specific wavelength. In addition, photoisomerization can be iteratively performed by ...
Michiels Nico K - - 2008
At depths below 10 m, reefs are dominated by blue-green light because seawater selectively absorbs the longer, 'red' wavelengths beyond 600 nm from the downwelling sunlight. Consequently, the visual pigments of many reef fish are matched to shorter wavelengths, which are transmitted better by water. Combining the typically poor long-wavelength ...
Wang Yue-Ting - - 2007
Laser flash photolysis of the quinol ester 2b in O2-saturated aqueous phosphate buffer at pH 7.1 with excitation at 266 nm generates a transient intermediate with lambda(max) 460 nm that decays in a first-order manner with an aqueous solution lifetime of (170 +/- 10) ns at 22 degrees C. This ...
Farkas Eszter E Division of Pharmacology, School of Life Sciences, University of Bradford, Bradford, - - 2008
Perilesion depolarisations, whether transient anoxic depolarisation (AD) or spreading depression (SD), occur in stroke models and in patients with acute brain ischaemia, but their contribution to lesion progression remains unclear. As these phenomena correspond to waves of cellular depolarisation, we have developed a technique for their live imaging with a ...
Aitken Colin Echeverría - - 2008
The application of single-molecule fluorescence techniques to complex biological systems places demands on the performance of single fluorophores. We present an enzymatic oxygen scavenging system for improved dye stability in single-molecule experiments. We compared the previously described protocatechuic acid/protocatechuate-3,4-dioxygenase system to the currently employed glucose oxidase/catalase system. Under standardized conditions, ...
Hashizume Midori - - 2007
Cloudy apple juice has been found to develop off-flavors during storage in daylight. The development of off-flavors and volatile compounds was monitored in reconstituted juice prepared from 'Golden Delicious' and 'Fuji' apple concentrates stored in glass bottles under fluorescent light (3000 lx, 8 degrees C). A strong metallic off-flavor was ...
Mandon J - - 2007
An infrared high-brightness light source based on supercontinuum generation through a SF6 photonic crystal fiber seeded by a Cr(4+):YAG femtosecond oscillator is developed for high resolution multiplex spectroscopy in the 1.5 μm region. Moreover, a multiplex high resolution approach based on a Cr(4+):YAG frequency comb enables to probe large spectral ...
Kumar Duvvuri Prasanna - - 2007
Exposure of algae or plants to irradiance from above the light saturation point of photosynthesis is known as high light stress. This high light stress induces various responses including photoinhibition of the photosynthetic apparatus. The degree of photoinhibition could be clearly determined by measuring the parameters such as absorption and ...
Deheyn Dimitri D - - 2007
Freshly collected samples of luminous mycelium of a terrestrial fungus from Panama were investigated for their bioluminescence characteristics. Taxonomic identification of fungal species could not be determined because of the lack of fruiting bodies. Fluorescence excited by 380 nm illumination had an emission spectrum with a main peak at 480 ...
Biermann T W - - 2007
Samples of blue and red cotton fibres were examined using light and fluorescence microscopy as well as UV/VIS microspectrophotometry and fluorescence microspectroscopy. The degree of fluorescence and spectral variation was recorded. Particular attention was paid to the recurrence of certain spectral patterns. The importance of spectral information in the UV ...
Ando Yoriko - - 2007
We have developed a bio/chemiluminescence spectrometer with a cooled charge-coupled-device (CCD) detector to obtain a quantitative luminescence spectrum as the absolute number of all emitted photons at each wavelength. The integrated area of the spectrum divided by the number of reacted substrate molecules gives the quantum yield. Calibration of the ...
Marwani Hadi M - - 2007
This study introduces a newly developed frequency segmentation and recombination method for frequency-domain fluorescence lifetime measurements to address the effects of changing fractional contributions over time and minimize the effects of photobleaching within multi-component systems. Frequency segmentation and recombination experiments were evaluated using a two component system consisting of fluorescein ...
Takenaka Manami - - 2007
It is generally assumed that light has no effect on the physiology of oocytes, zygotes, or early embryos. Therefore, little or no attention has been paid to lighting conditions during the handling of these cells in vitro. Here we show that cool white fluorescent light, rich in short-wavelength visible light ...
O'Riordan Katie - - 2007
An objective was to explore the photodynamic activity of two cationic photosensitizers (PS) (benzo[a]phenothiazinium chloride and benzo[a]phenoselenazinium chloride) against Mycobacterium bovis BCG both in vitro and in a murine model of BCG-granuloma. The hypothesis being tested in this study was that cationic molecules could best interact with the negatively charged ...
Wang Long L College of Materials Science and Engineering, Chengdu 610064, Sichuan Province, - - 2007
To investigate the apoptotic effect of photoexcited titanium dioxide (TiO(2)) nanoparticles in the presence of visible light on human hepatoma cell line (Bel 7402) and to study the underlying mechanism. Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium ...
Iwai Masakazu - - 2007
Mechanisms for countering environmental stress are essential to photosynthetic organisms. Alteration of the photosynthetic apparatus, a mechanism for balancing the flux of light energy and carbon fixation, can be characterized by fluorescence properties. In this study, we have established a simple protocol to determine the extent of energy-dependent quenching (qE) ...
Ye Jing Yong - - 2007
We have developed a new detection mechanism for ultrabroadband multicolor fluorescence detection using an ultrafast supercontinuum white light source without spectral filtering to simultaneously excite different fluorophores. A nonlinear photonic crystal fiber was utilized in conjunction with a femtosecond laser to generate the supercontinuum. A time-resolved detector was tested to ...
Fouqueray Manuela - - 2007
In order to investigate the dynamics of the acclimation of marine diatoms to ultraviolet radiation (UVR), Amphora coffeaeformis, Odontella aurita and Skeletonema costatum were exposed for 5 h per day to a combination of UVA and UVB (UVBR/UVAR ratio 4.5%) with a total UVR daily dose of 110 kJ m(-2), ...
Ellis-Davies Graham C R GC Department of Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA. - - 2007
Caged compounds are light-sensitive probes that functionally encapsulate biomolecules in an inactive form. Irradiation liberates the trapped molecule, permitting targeted perturbation of a biological process. Uncaging technology and fluorescence microscopy are 'optically orthogonal': the former allows control, and the latter, observation of cellular function. Used in conjunction with other technologies ...
Cabrales Pedro - - 2007
The possibility of a plasma oxygen diffusion barrier implies a significant resistance to oxygen diffusion and the existence of capillary erythrocyte-associated transients of oxygen. This effect was analyzed by measuring intracapillary blood and tissue pO(2) in the hamster chamber window model using a noninvasive intravital microscopy palladium porphyrin phosphorescence decay ...
Bhagat Ali Asgar S - - 2007
In this paper, we introduce a new and simple method of patterning polydimethylsiloxane (PDMS) directly using benzophenone as a photoinitiator. The photodefinable PDMS mixture (photoPDMS) is positive-acting and only sensitive to light below 365 nm, permitting processing under normal ambient light. Features of the order of 100 microm, which are ...
Ryderfors Linus - - 2007
Theoretical expressions are derived that relate the two-photon excited fluorescence depolarisation experiments to the molecular symmetry and the rotational motions of fluorescent molecules. Diffusive rotational motions in liquid solvents are considered, as well as the influence of fast unresolved motions (e.g. librations). The results obtained are compared with one-photon excited ...
Cordón Gabriela B - - 2007
Emission fluorescence spectra were obtained for the adaxial and abaxial faces of dicotyledonous (Ficus benjamina L., Ficus elastica, Gardenia jasminoides and Hedera helix) and monocotyledonous leaves (Gladiolus spp. and Dracaena cincta bicolor). After correction by light-re-absorption processes, using a previously published physical model, the adaxial faces of dicotyledons showed a ...
Fukuda Takeshi - - 2007
We have demonstrated a short fluorescence lifetime of the substituted phenyl/vinyl compound, 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (DSB). The fluorescence lifetime of the 0.5 mol.% DSB-doped 4,4'-bis(9-carbazolyl)biphenyl film is 1.2 ns, which is desirable for organic light-emitting diode (OLED) light sources for optical interconnect applications. We have also examined frequency dependences on the electroluminescence ...
Caorsi V - - 2007
In the last decade, fluorescence resonance energy transfer (FRET) has become a useful technique for studying intermolecular interactions applied to the analysis of biological systems. Although FRET measurements may be very helpful in the comprehension of different cellular processes, it can be difficult to obtain quantitative results, hence the necessity ...
Henderson J Nathan - - 2007
Fluorescent protein (FP) variants that can be reversibly converted between fluorescent and nonfluorescent states have proven to be a catalyst for innovation in the field of fluorescence microscopy. However, the structural basis of the process remains poorly understood. High-resolution structures of a FP derived from Clavularia in both the fluorescent ...
Schmidt Oliver - - 2007
A chip-size spectrometer is realized by combining a linear variable band-pass filter with a CMOS camera. The filter converts the spectral information of the incident light into a spatially dependent signal that is analyzed by the camera. A fluidic platform is integrated onto the spectrometer for analyzing the fluorescence from ...
Lu Joann J - - 2007
Capillary array electrophoresis (CAE) is an important high throughput analytical technique. Laser-induced fluorescence (LIF) has been the dominant detection method for CAE owing to its low limit of detection (LOD) and wide linear dynamic range (LDR). Linear LIF scanners were first used in CAE because linear motions of an objective ...
Cannone F - - 2007
An organic dye, SAMSA, bound to gold nanoparticles, displays random photoactivated fluorescence blinking whose rate depends on the size of the nanoparticles. We report experiments indicating that (1) the dye emission wavelength is red-shifted (10-30 nm) by applying an external low voltage (1-10 V) and that (2) the fluorescence emission ...
Dewez David - - 2007
Rapid chlorophyll fluorescence transient induced by saturating flash (3000 micromol of photons m-2 s-1) was investigated when Lemna gibba had been exposed to light (100 micromol of photons m-2 s-1) causing the Kautsky effect or in low light intensity unable to trigger PSII photochemistry. Measurements were made by using, simultaneously, ...
Wilson Adjélé - - 2007
In response to iron deficiency, cyanobacteria synthesize the iron stress-induced chlorophyll binding protein IsiA. This protein protects cyanobacterial cells against iron stress. It has been proposed that the protective role of IsiA is related to a blue light-induced nonphotochemical fluorescence quenching (NPQ) mechanism. In iron-replete cyanobacterial cell cultures, strong blue ...
Yasuda Keiji - - 2007
The ultrasonic reactor with dual frequency was used and the effect of frequency on the fluorescence intensity of terephthalate ion was experimentally investigated in the frequency range from 176 to 635 kHz. The sonochemical reaction fields were visualized by using sonochemical luminescence of luminol solution. Compared with the fluorescence intensity ...
Liu Zheng-Chun - - 2007
We report herein the light-directed synthesis of peptide nucleic acids (PNAs) microarray using PNA monomers protected by photolabile protecting groups and a maskless technique that uses a digital micromirror array system to form virtual masks. An ultraviolet image from the virtual mask was cast onto the active surface of a ...
Tu Chuqiao C Department of Biomedical Engineering, University of California, Davis, CA 95616, - - 2007
The contrast agent which tethers a spiropyran group to a Gd-DO3A moiety has higher relaxivity and fluorescence intensity in the dark; the relaxivity and fluorescence intensity decrease after irradiation with visible light.
Levitan Edwin S - - 2007
Recently, it has become possible to directly detect changes in neuropeptide vesicle dynamics in nerve terminals in vivo and to measure the release of neuropeptides induced experimentally or evoked by normal behavior. These results were obtained with the use of transgenic fruit flies that express a neuropeptide tagged with green ...
Carr Herman - - 2007
The photosynthetic response to a sudden and prolonged high irradiance exposure and following recovery at low irradiance were studied with the aim of investigating the ability to withstand and adapt to high irradiance without prior high light adaptation. When thalli of Ulva fasciata, accustomed to a low irradiance (80 micromol ...
Rappaport Fabrice - - 2007
In photosynthetic chains, the kinetics of fluorescence yield depends on the photochemical rates at the level of both Photosystem I and II and thus on the absorption cross section of the photosynthetic units as well as on the coupling between light harvesting complexes and photosynthetic traps. A new set-up is ...
Zimmermann Hartmut F - - 2006
The turbidity of a microbial suspension sample is routinely determined by measuring the optical density (often referred to as the "absorbance"). This method requires a dilution step at moderate and high cell densities in order to ensure that measurements fall within the region where biomass concentration is linearly correlated to ...
Serôdio João - - 2006
Rapid light-response curves (RLC) of variable chlorophyll fluorescence were measured on estuarine benthic microalgae with the purpose of characterising its response to changes in ambient light, and of investigating the relationship to steady-state light-response curves (LC). The response of RLCs to changes in ambient light (E, defined as the irradiance ...
Anthony R M - - 2006
We describe the simple adaptation of a standard fluorescent microscope for illumination using a 'Royal Blue' Luxeon light emitting diode (LED) and demonstrate that this form of illumination is suitable for the detection of auramine O stained Mycobacterium spp. The low cost, low power consumption, safety and reliability of LEDs ...
Yao Bo - - 2006
An integrated and simplified microfluidic device using a 250 microm x 1-4 cm of organic light emitting diode (OLED) array as a two-dimensional light source for single-channel and multichannel whole-column imaging detection was developed. This fluorescence detection system was used for isoelectric focusing (IEF) of R-phycoerythrin in a microchip. The ...
Wu Fei - - 2006
In this article, we report a new type of fluorescence confocal microscope: frequency division multiplexed multichannel fluorescence confocal microscope, in which we encode the spatial location information into the frequency domain. In this microscope, the exciting laser beam is first split into multiple beams and each beam is modulated at ...
Barták Milos - - 2006
This study aims to assess the photoprotective potential of desiccation-induced curling in the light-susceptible old forest lichen Lobaria pulmonaria by using chlorophyll fluorescence imaging. Naturally curled thalli showed less photoinhibition-induced limitations in primary processes of photosynthesis than artificially flattened specimens during exposures to 450 micromol m-2 s-1 in the laboratory ...
Floryszak-Wieczorek J - - 2006
Huge advances achieved recently in elucidating the role of NO in plants have been made possible by the application of NO donors. However, the application of NO to plants in various forms and doses should be subjected to detailed verification criteria. Not all metabolic responses induced by NO donors are ...
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