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Branchini B R - - 1989
In the course of investigations on the possible involvement of the CIEEL (chemically initiated electron-exchange luminescence) mechanism in firefly bioluminescence, we have synthesized two novel firefly luciferin substrate analogues. D-Naphthylluciferin and D-quinolylluciferin were prepared by condensing D-cysteine with 2-cyano-6-hydroxynaphthalene and 2-cyano-6-hydroxyquinoline, respectively. These analogues are the first examples of bioluminescent ...
Larcher W - - 1989
In chilling-sensitive plants (Glycine max, Saintpaulia ionantha, Saccharum officinarum) a sudden reversible drop in chlorophyll fluorescence occurs during photosynthetic induction immediately following saturating light pulses at low temperatures in the range 4 to 8 degrees C. A comparison of two soybean cultivars of different chilling sensitivities revealed that this phenomenon, ...
Bright F V - - 1989
The rotational dynamics of a phenytoin fluoroimmunoassay system is investigated by using multifrequency phase and modulation fluorescence spectroscopy. Results indicated that the fluorescein label on this relatively small hapten undergoes significant (greater than 45%) local motion even when bound to the phenytoin antibody. We attribute this local motion to unhindered ...
Schoenwolf G C - - 1989
Shaping and bending of the neural plate are cardinal events of neurulation. These processes are initiated in avian embryos shortly after the onset of gastrulation and concluded concomitantly with the completion of gastrulation. The epiblast undergoes extensive morphogenetic movements during gastrulation and neurulation, but the directions, distances, rates, mechanisms and ...
Robertson A S - - 1989
Office lighting has been suggested as one of the possible factors in producing 'building sickness'. Health questionnaires were completed by 106 out of 109 (97%) workers in six randomly sampled multi-occupied offices in each of two buildings, one air-conditioned and one naturally ventilated. There was a significantly higher prevalence of ...
Lakowicz J R - - 1988
We describe the principles, instrumentation and applications of frequency-domain fluorescence spectroscopy. This method is useful for the resolution of multi-exponential decays and complex anisotropy decays on the picosecond timescale. The present instrumentation allows measurements to 2 GHz, which has been used to measure rotational correlation times as short as 7 ...
Elbaum D J - - 1988
After 4 hours of exposure to incandescent light, 80% of 0.05% topical isotretinoin and 60% of 0.05% topical tretinoin preparations remained in their original form. In contrast, after 2 hours of exposure to fluorescent light only 25% of topical tretinoin and possibly 60% of topical isotretinoin remained in their original ...
Thayer S A - - 1988
Fluorescent indicator molecules, such as fura-2, are useful probes for studying the concentrations of ions in single cells. A key feature of these fluorescent dyes is the shift in their excitation spectra upon binding the ion, thus making alternate excitation from two wavelengths desirable. In this report we describe an ...
Eggert P - - 1988
The efficacy of various irradiation regimens in phototherapy of neonatal hyperbilirubinaemia was analysed. One hundred and one newborns were assigned to three groups at random. The best results were achieved when six special blue fluorescent lamps were used and the sides of the incubator were draped with white cloth to ...
Moan J - - 1988
Fluorescence and absorption spectra of light-exposed cells containing the tumour-localizing porphyrin preparation Photofrin II (PII) have been studied. Light exposure results in spectral changes that may be due to a photoinduced modification of the porphyrins without breakage of the porphyrin macrocycle and/or to a photoinduced displacement of the porphyrins in ...
Bose S - - 1988
The effects of light treatment (2000 micromole photons per square meter per second) for varying periods (up to 60 minutes) on chlorophyll fluorescence characteristics and light-limited rates of O(2) evolution were examined in two Porphyra species. Brief light exposures (5-60 seconds) produced a large decrease in variable fluorescence which was ...
Li Q - - 1988
The lack of detectable variable fluorescence from guard cell chloroplasts in both the albino and green portions of variegated leaves of St. Augustine grass (Stenotaphrum secundatum var variegatum A.S. Hitchc.) is reported. Fluorescence was measured either with a highly sensitive, modified fluorescence microscope which was capable of recording fluorescence induction ...
Scheuerlein R - - 1988
A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated ...
Wendler J - - 1987
Decay-associated fluorescence spectra of the green alga Scenedesmus obliquus have been measured by single-photon timing with picosecond resolution in various states of light adaptation. The data have been analyzed by applying a global data analysis procedure. The amplitudes of the decay-associated spectra allow a determination of the relative antenna sizes ...
Szmacinski H - - 1987
We used frequency-domain fluorometry to demonstrate the presence of an associated decay of fluorescence anisotropy. In such systems the individual correlation times are associated with distinct emitting species, each with its own characteristic lifetime and rotational correlation times. We obtained an associated system using 1-anilino-8-naphthalenesulfonic acid (ANS) in the presence ...
Steinkamp J A - - 1987
A modular detector for measuring multicolor fluorescence from cells illuminated by single or multiple lasers has been developed for flow cytometers. Motion picture projector, camera, and CCTV/video lenses were evaluated for use in the detector by comparing their physical characteristics, image quality, and light collection efficiencies. A 25-mm focal length ...
Demmig B - - 1987
Comparative studies of chlorophyll a fluorescence, measured with a pulse amplitude modulated fluorometer, and of the pigment composition of leaves, suggest a specific role of zeaxanthin, a carotenoid formed in the xanthophyll cycle, in protecting the photosynthetic apparatus against the adverse effects of excessive light. This conclusion is based on ...
Krones M J - - 1987
This paper describes a closed-loop control system for controlling the irradiance and spectral quality generated by fluorescent lamps in a controlled environment chamber. The 400 to 800 nm irradiance and the ratio of the red waveband (600 to 700 nm) to the far-red waveband (700 to 800 nm) were independently ...
Swatland H J - - 1987
The autofluorescence of tendon, epimysium and endomysium at the myotendon junction of the deep digital flexor in the bovine forelimb was measured with a fluorescence microscope and with a bifurcated light guide composed of quartz optical fibres. Data were adjusted for spectral variation in the radiance of the halogen illuminator ...
Wells B D - - 1987
The intensity and anisotropy decays of Wye base fluorescence from yeast tRNA(Phe) were determined by frequency-domain fluorometry. The intensity decay is at least a double exponential in the presence and absence of Mg2+, but the multi-exponential character of the decay is more pronounced in the absence of Mg2+. The anisotropy ...
Lakowicz J R - - 1987
We describe a general method to correct for contaminant fluorescence when using the technique of frequency-domain fluorometry. The method can be applied regardless of the origin of the background signal, from scattered light, impurity fluorescence, or both. The procedure requires measurement of the frequency-dependent phase and modulation of the background ...
Fernö A A Department of Fisheries Biology, University of Bergen, P.O. Box 1839, N-5011 Bergen, - - 1986
The development of aggression between territorial fish has mainly been studied in laboratory experiments using only visual contact. In this study, comparisons of the aggressive behaviour were made between conditions of unlimited and only visual contact. Fighting between two territorial cichlids in direct contact decreased over time in a way ...
Longeon A - - 1986
A solid-phase luminescent immunoassay (LIA), based on the light emission produced as a result of the oxidation of Pholas dactylus luciferin by horseradish peroxidase (HRP) in the presence of molecular oxygen, was developed for human chorionic gonadotropin (hCG). The light emitted in the presence of diethyldithiocarbamate permitted the detection of ...
Owens T G - - 1986
The distribution of excitation energy between photosystems I and II (PSI and PSII) was investigated in the marine diatom Phaeodactylum tricornutum (Bohlin) using light-induced changes in fluorescence yield and rate of modulated O(2) evolution. The intensity dependence of the fast fluorescence rise in dark adapted cells (+/-DCMU) suggests that light ...
Lakowicz J R - - 1986
We report the first anisotropy decays of protein fluorescence obtained using a frequency-domain fluorometer. The ultraviolet light source (300 nm) was a ring dye laser equipped with an intracavity frequency doubler, pumped by an argon ion laser. The data, measured at modulation frequencies from 2 to 200 MHz, reveal the ...
Marwaha R K - - 1986
The long-term stability of histamine in sterile bronchoprovocation solutions stored under different conditions was studied. Histamine solutions (2 and 8 mg/mL) were stored in specially adapted translucent and black plastic bottles and kept in a cool place (12 degrees C) and exposed to fluorescent light (500 foot-candles intensity). Multiple aliquots ...
Mauzerall D C - - 1985
The fluorescence lifetime of oxygen-forming photosynthetic systems as a function of closed traps has been studied by several groups using light and poisons (usually 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)) to fix the closed trap state during the experiment. These measurements have now been carried out using light alone, by means of pump and ...
English D R - - 1985
A population-based case-control study of cutaneous malignant melanoma occurring during 1980-81 was conducted in Perth, Western Australia. Three hundred and thirty-seven cases and 349 matched controls were reinterviewed in 1983 with regard to their fluorescent light exposure. The incidence rate of all melanomas was not associated with rate of exposure ...
Sivak M N - - 1985
Light scattering, which can be taken as an indicator of the transthylakoid proton gradient, and the 518-nm rise, which can be regarded as a measure of the transthylakoid membrane potential, have been followed during oscillations in chlorophyll a fluorescence, which are known to be associated with corresponding changes in photosynthetic ...
Chen J F - - 1985
Various light sources, including ultraviolet light, mercury, germicidal, fluorescent, and incandescent lamps, were studied for their ability to induce sister chromatid differentiation (SCD) in rat bone marrow cells. The light sources were used along with Hoechst 33258 and Giemsa stains for SCD induction. When those lamps which emit significant amounts ...
Melø T B - - 1985
The fluorescence spectra of colonies of Propionibacterium acnes were studied under various experimental conditions. The spectra contained peaks at 580 nm and 620 nm. These bands were due to two different components; the 580 nm component was likely to be a metalloporphyrin, and there are indications that the 620 nm ...
Harber L C - - 1985
The most frequently used source of indoor lighting is the fluorescent tube. Although there are major variations in phosphors, the majority of these lamps are safe, efficient, and economical illuminators. These fluorescent light sources are currently our primary source of visible light; however, they emit small amounts of ultraviolet A ...
White G L - - 1985
To determine the effect of artificially produced light on the direct mutagenicity of 2-aminofluorene, that arylamine was irradiated with either sun, cool-white, black, blue, or yellow fluorescent light or held in the dark prior to assaying for mutagenicity using Salmonella typhimurium strain TA98. The effectiveness of these exposures in potentiating ...
Sundström F - - 1985
Fluorescence spectra of dentine and enamel illuminated with laser light of wavelengths of 337, 488, 515 and 633 nm respectively were recorded. The fluorescence obtained by illumination with UV laser light at 337 nm had a peak at about 400 nm in dentine as well as enamel. Compared to intact ...
Mosier M A - - 1985
A variety of mechanical (intensity of the light source, the width and the angle of the exciting source) and physiological factors (retinal pigmentation, vitreous fluorescence) and many systemic factors affect the results of vitreous fluorophotometry. These factors are discussed with respect to identifying those that are inconsequential and those that ...
van Best J A - - 1985
A simple quantitative and reproducible method for evaluating lens transmission (lambda = 490 and 530 nm) is described. It is based on the measurement of autofluorescence in the anterior and the posterior part of the lens by means of a fluorophotometer, assuming an about equal fluorescence quantum efficiency in both ...
Lahav N - - 1985
Dehydration-induced luminescence (DIL), the emission of light from a clay paste upon dehydration, was characterized experimentally for a colloidal kaolinite. The relationship between total photon count of the emitted light and film thickness is linear up to a thickness of 30 micrometers. The photon emission was obtained over a critical ...
Wegener W A - - 1984
Although fluorescence photobleaching recovery (FPR) experiments are usually interpreted in terms of the translational motions of a fluorescently labeled species, rotational motions can also modulate recovery through the cosine-squared laws for dipolar absorption and emission processes. In a complex interacting system, translational and rotational contributions may both be simultaneously present. ...
Uhl R - - 1984
A wide variety of biologically relevant chemical intermediates have been identified and characterised by their spectral properties. When rapid kinetics, i.e. rapid changes in these spectral properties are studied, the equipment designed for these studies (flash photolysis-, T-jump apparatus) usually allows only the registration of intensity changes of the monitoring ...
Whitley R D - - 1984
Numerous investigations of light induced avian buphthalmia using incandescent light have not defined an etiology. Chickens raised from 2 weeks of age in continuous fluorescent light developed shallow anterior chambers and buphthalmos within the first month of treatment. Chickens raised in continuous fluorescent light developed ocular enlargement similar to that ...
Finan M C - - 1984
Direct immunofluorescence microscopy was positive in 88% of forty-one skin biopsy specimens from thirty-four patients with the clinical diagnosis of erythema multiforme. The most common finding, present in 67% of positive specimens, was the cytoid body, or fluorescent keratinocyte, which stained most often with IgM (homogeneously) or with C3 (speckled). ...
Wachsmuth E D - - 1984
A fully automatic analysis system based on television image analysis was developed to measure simultaneously three parameters in individual nuclei of microscopic autoradiographs prepared from mouse jejunal crypt cell squashes and ascites tumor cell smears: size, Feulgen fluorescence and reflection from silver grains. A dark light camera with an image ...
Eysel U T - - 1984
Single neurons in the cat visual system respond distinctly to the temporal information present in light from fluorescent tubes driven by 50 or 60 Hz alternating current. Despite the resulting flicker frequencies of 100 or 120 Hz all retinal and most thalamic neurons show strong phase locking of the neuronal ...
Masters B R - - 1984
Ultraviolet light can result in corneal, lenticular and retinal damage; however it can also be used (at much lower intensities) to measure the light induced alteration of cellular respiration and function. Mitochondrial function can be measured by noninvasive redox fluorometry which measures the intrinsic mitochondrial fluorescence of the reduced pyridine ...
Creekmore S P - - 1983
Tissue culture experiments were done to evaluate the possibility of modifying the response curves of phenylalanine mustard (LPAM) and actinomycin D on L1210 cells, using moderately toxic levels of photodynamic injury provided by light and hematoporphyrin (HP). Cells were grown and treated in Roswell Park Memorial Institute Medium 1630 containing ...
Cotrufo R - - 1983
An easy-to-assemble apparatus for the laser-light excitation of fluorofores in polyacrylamide gels is described. The assemblage is made up of a continuous-wave ion-argon laser with adjustable power output, a beam diffuser, appropriate filters to block excitation light, and a photographic camera. With this setup a minimum 20-fold increase of sensitivity ...
Martin L - - 1983
A 50-year-old woman with systemic lupus erythematosus (SLE) developed a severe rash on her back and shoulders after exposure to fluorescent light while she was a hospital inpatient. Even small amounts of ultraviolet irradiation, such as that emitted by a domestic fluorescent tube, may be harmful to some patients with ...
Stanger J D - - 1983
Mouse epididymal spermatozoa exposed to fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) immediately following dilution or after a 2-hour incubation period under fertilization conditions, were assessed by fluorescence microscopy for albumin adsorption. Motile spermatozoa exhibited light fluorescence in the midpiece and tail but not in the head. In contrast the majority ...
Cannell M B - - 1983
Bioluminescent indicators have found many uses in, for example, the detection of ATP and free calcium levels. However, such probes often emit only very low levels of light and it is important to optimize the efficiency of the system used to detect this light. We describe some of the problems ...
Mann J L - - 1983
Many pathogenic fungi have been found to autofluoresce in routine hematoxylin and eosin sections when exposed to ultraviolet light. These fungi include Blastomyces, Cryptococcus, Candida, Aspergillus, Coccidioides, and occasionally, Histoplasma. No autofluorescence was observed with Mucor. Examinations of other inflammatory processes, including those producing a granulomatous response, have not revealed ...
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