125 resultados para Light sensitive materials
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Background and Objectives We have undertaken the first clinical trial involving the administration of alpha-GalactosylCeramine (alpha-GalCer)-pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects. Materials and Methods Subjects (n = 4) with metastatic malignancy received two infusions of alpha-GalCer-pulsed DCs intravenously, and two infusions intradermally. The percentages of Valpha24 Vbeta11 NKT cells in peripheral blood (PB) were determined by three-colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full-blood counts. Results No serious treatment related adverse events were observed during the study period. Administration of alpha-GalCer-pulsed DCs in vivo can significantly (P < 0.03) increase PB Valpha24(+) Vbeta11(+) NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h. Conclusions Administration of alpha-GalCer-pulsed DCs is well tolerated, modulates PB Valpha24(+) Vbeta11(+) NKT cells and may have a role in the therapy of malignancies sensitive to activities of Valpha24(+) Vbeta11(+) NKT cells, or for autoimmune diseases.
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A technique based on laser light diffraction is shown to be successful in collecting on-line experimental data. Time series of floc size distributions (FSD) under different shear rates (G) and calcium additions were collected. The steady state mass mean diameter decreased with increasing shear rate G and increased when calcium additions exceeded 8 mg/l. A so-called population balance model (PBM) was used to describe the experimental data, This kind of model describes both aggregation and breakage through birth and death terms. A discretised PBM was used since analytical solutions of the integro-partial differential equations are non-existing. Despite the complexity of the model, only 2 parameters need to be estimated: the aggregation rate and the breakage rate. The model seems, however, to lack flexibility. Also, the description of the floc size distribution (FSD) in time is not accurate.
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Purinergic stimulation of airway epithelial cells induces Cl- secretion and modulates Na+ absorption by an unknown mechanism. To gain insight into this mechanism, we used a perfused micro-Ussing chamber to assess transepithelial voltage (V-te) and amiloride-sensitive short-circuit current (Isc-Amil) in mouse trachea. Exposure to apical ATP or UTP (each 100 mumol/l) caused a large initial increase in lumen negative V-te and I-sc corresponding to a transient Cl- secretion, while basolateral application of ATP/UTP induced only a small secretory response. Luminal, but not basolateral, application of nucleotides was followed by a sustained and reversible inhibition of Isc-Amil that was independent of extracellular Ca2+ or activation of protein kinase C and was not induced by carbachol (100 mumol/l) or the Ca2+ ionophore ionomycin (1 mumol/l). Removal of extracellular Cl- or exposure to 200 muM DIDS reduced UTP-mediated inhibition of Isc-Amil Substantially. The phospholipase inhibitor U73122 (10 mumol/l) and pertussis toxin (PTX 200 ng/ml) both attenuated UTP-induced Cl- secretion and inhibition of Isc-Amil. Taken together, these data imply a contribution of Cl- conductance and PTX-sensitive G proteins to nucleotide-dependent inhibition of the amiloride-sensitive Na+ current in the mouse trachea.
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Aquaporin 1 (AQP1; also known as CHIP, a channel-forming integral membrane protein of 28 kDa) is the first protein to be shown to function as a water channel and has been recently shown to be present in the rat retina. We previously showed (Kim et al. [1998] Neurosci Lett 244:52-54) that AQP1-like immunoreactivity is present in a certain population of amacrine cells in the rat retina. This study was conducted to characterize these cells in more detail, With immunocytochemistry using specific antisera against AQP1, whole-mount preparations and 50-mum-thick vibratome sections were examined by light and electron microscopy. These cells were a class of amacrine cells, which had symmetric bistratified dendritic trees ramified in stratum 2 and in the border of strata 3 and 4 of the inner plexiform layer (IPL). Their dendritic field diameters ranged from 90 to 230 mum. Double labeling with antisera against AQP1 and gamma-aminobutyric acid or glycine demonstrated that these AQP1-like-immunoreactive amacrine cells were immunoreactive for glycine. Their most frequent synaptic input was from other amacrine cell processes in both sublaminae a and b of the IPL, followed by a few cone bipolar cells. Their primary targets were other amacrine cells and ganglion cells in both sublaminae a and b of the IPL. In addition, synaptic output Onto bipolar cells was rarely observed in sublamina b of the IPL. Thus, the AQP1 antibody labels a class of glycinergic amacrine cells with small to medium-sized dendritic fields in the rat retina. (C) 2002 Wiley-Liss, Inc.
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Acclimation of gas exchange to temperature and light was determined in 18-month-old plants of humid coastal (Gympie) and dry inland ( Hungry Hills) provenances of Eucalyptus cloeziana F. Muell., and in those of a dry inland provenance of Eucalyptus argophloia Blakely. Plants were acclimated at day/night temperatures of 18/13, 23/18, 28/23 and 33/ 28 degreesC in controlled-temperature glasshouses for 4 months. Light and temperature response curves were measured at the beginning and end of the acclimation period. There were no significant differences in the shape and quantum-yield parameters among provenances at 23, 28 and 33 degreesC day temperatures. Quantum yield [mumol CO2 mumol(- 1) photosynthetic photon flux density (PPFD)] ranged from 0.04 to 0.06 and the light response shape parameter ranged from 0.53 to 0.78. Similarly, no consistent trends in the rate of dark respiration for plants of each provenance were identified at the four growth temperatures. Average values of dark respiration for the plants of the three provenances ranged from 0.61 to 1.86 mumol m(-2) s(-1). The optimum temperatures for net photosynthesis increased from 23 to 32 degreesC for the humid- and from 25 to 33 degreesC for the dry-provenance E. cloeziana and from 21 to 33 degreesC for E. argophloia as daytime temperature of the growth environment increased from 18 to 33 degreesC. These results have implications in predicting survival and productivity of E. cloeziana and E. argophloia in areas outside their natural distribution.
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This study evaluated the suitability of written materials for stroke survivors and their carers. Twenty stroke survivors and 14 carers were interviewed about the stroke information they had received and their perceptions of the content and presentation of materials of increasing reading difficulty. The mean readability level of materials (grade 9) was higher than participants’ mean reading ability (grade 7–8). Satisfaction with materials decreased as the content became more difficult to read. Seventy-five percent reported that their information needs were not met in hospital. More stroke survivors with aphasia wanted support from health professionals to read and understand written information, and identified simple language, large font size, color, and diagrams to complement the text as being important features of written materials. Simple materials that meet clients’ information needs and design preferences may optimally inform them about stroke.
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Low-temperature anneals (1200 degreesC for 40 h) of 8 mol% yttria-stabilised zirconia, prior to the samples being sintered at 1500 degreesC, had the effect of improving the ionic conductivity of the specimens. The presence Of SiO2 in the specimens was shown to be detrimental, however. Irrespective of the SiO2 content, this type of heat treatment also leads to improvements in conductivity. Extensive microstructural analysis provided indication of the mechanism of this phenomenon. This included selective formation of zircon, relief of sintering strain leading to the formation of coherent grain boundaries and segregation effects. (C) 2002 Elsevier Science B.V All rights reserved.
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The toadfishes Tetractenos hamiltoni and Torquigener pleurogramma (Tetraodontidae) possess occlusable yellow corneas. We examine the light transmission and location of the yellow/orange pigment throughout the cornea, the temporal properties of pigment migration and the ultrastructure of the pigmented processes during light- and dark-adaptation. Each species was dark-adapted during the day and light-adapted during the night and then exposed to either sun illumination or darkness for different lengths of time (0-70 min). Movement of corneal pigment could be induced in both species regardless of time of day or night. The pigment was able to migrate in a dorsal or ventral direction and changed from minimal to maximal pigmentation within 60 min. Three types of transmission curves were found with varying degrees of transmission in the 400-500 nm waveband, indicating that the pigment distribution is not uniform across the cornea; some areas of the cornea transmit near UV light, while others absorb blue light. The gradual change of the transmission characteristics in different areas of the cornea indicates the presence of different concentrations of a single type of pigment. Ultrastructural examination of the corneas showed that the layer containing the pigment is situated within the scleral cornea either surrounding (T. pleurogramma) or abutting (T. hamiltoni) an iridescent layer. Long sheet-like processes or chromatophores extending centrally from dorsal and ventral reservoirs are filled with pigment during the light-adapted state but empty in the dark-adapted state.
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The large eyes and well-developed visual system of billfishes suggest that vision is an important sense for the detection and interception of prey and lures. Investigations of visual abilities in these large pelagic fishes are difficult, however anatomical studies of billfish eyes and retinas allow prediction of a number of visual capabilities. From the density of ganglion cells in the blue marlin (Makaira nigricans) retina, visual acuities of less than 10 cycles per degree were derived, a surprisingly low visual resolution given the absolute size of the marlin eye. Cone photoreceptors, on the other hand, were present in high densities, resulting in a presumed summation of cones to ganglion cells at a ratio of 40:1, even in the area of best vision. The optical sensitivity of the marlin eye was high owing to the large dimensions of the cone photoreceptors. These results indicate that the marlin eye is specifically adapted to cope with the low light levels encountered during diving. Since the marlin is likely to use its vision at depth, it is suggested that this line of research could help estimate the limits of vertical distribution based on light level.
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Chlorophyll fluorescence measurements have a wide range of applications from basic understanding of photosynthesis functioning to plant environmental stress responses and direct assessments of plant health. The measured signal is the fluorescence intensity (expressed in relative units) and the most meaningful data are derived from the time dependent increase in fluorescence intensity achieved upon application of continuous bright light to a previously dark adapted sample. The fluorescence response changes over time and is termed the Kautsky curve or chlorophyll fluorescence transient. Recently, Strasser and Strasser (1995) formulated a group of fluorescence parameters, called the JIP-test, that quantify the stepwise flow of energy through Photosystem II, using input data from the fluorescence transient. The purpose of this study was to establish relationships between the biochemical reactions occurring in PS II and specific JIP-test parameters. This was approached using isolated systems that facilitated the addition of modifying agents, a PS II electron transport inhibitor, an electron acceptor and an uncoupler, whose effects on PS II activity are well documented in the literature. The alteration to PS II activity caused by each of these compounds could then be monitored through the JIP-test parameters and compared and contrasted with the literature. The known alteration in PS II activity of Chenopodium album atrazine resistant and sensitive biotypes was also used to gauge the effectiveness and sensitivity of the JIP-test. The information gained from the in vitro study was successfully applied to an in situ study. This is the first in a series of four papers. It shows that the trapping parameters of the JIP-test were most affected by illumination and that the reduction in trapping had a run-on effect to inhibit electron transport. When irradiance exposure proceeded to photoinhibition, the electron transport probability parameter was greatly reduced and dissipation significantly increased. These results illustrate the advantage of monitoring a number of fluorescence parameters over the use of just one, which is often the case when the F-V/F-M ratio is used.
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Background: Provision of health information to people with aphasia is inadequate. Current practice in providing printed health education materials to people with aphasia does not routinely take into consideration their language and associated reading difficulties. Aims: This study aimed to investigate if people with aphasia can comprehend health information contained in printed health education materials and if the application of aphasia-friendly principles is effective in assisting them to comprehend health information. It was hypothesised that participants with aphasia would comprehend significantly more information from aphasia-friendly materials than from existing materials. Other aims included investigating if the effectiveness of the aphasia-friendly principles is related to aphasia severity, if people with aphasia are more confident in responding to health information questions after they have read the aphasia-friendly material, if they prefer to read the aphasia-friendly brochures, and if they prefer to read the brochure type that resulted in the greatest increase in their knowledge. Methods & Procedures: Twelve participants with mild to moderately severe aphasia were matched according to their reading abilities. A pre and post experimental design was employed with repeated measures ANOVA (p
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This paper presents a large amplitude vibration analysis of pre-stressed functionally graded material (FGM) laminated plates that are composed of a shear deformable functionally graded layer and two surface-mounted piezoelectric actuator layers. Nonlinear governing equations of motion are derived within the context of Reddy's higher-order shear deformation plate theory to account for transverse shear strain and rotary inertia. Due to the bending and stretching coupling effect, a nonlinear static problem is solved first to determine the initial stress state and pre-vibration deformations of the plate that is subjected to uniform temperature change, in-plane forces and applied actuator voltage. By adding an incremental dynamic state to the pre-vibration state, the differential equations that govern the nonlinear vibration behavior of pre-stressed FGM laminated plates are derived. A semi-analytical method that is based on one-dimensional differential quadrature and Galerkin technique is proposed to predict the large amplitude vibration behavior of the laminated rectangular plates with two opposite clamped edges. Linear vibration frequencies and nonlinear normalized frequencies are presented in both tabular and graphical forms, showing that the normalized frequency of the FGM laminated plate is very sensitive to vibration amplitude, out-of-plane boundary support, temperature change, in-plane compression and the side-to-thickness ratio. The CSCF and CFCF plates even change the inherent hard-spring characteristic to soft-spring behavior at large vibration amplitudes. (C) 2003 Elsevier B.V. All rights reserved.
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Conventional kinesin is a microtubule-based molecular motor involved in the transport of membranous and non-membranous cargoes. The kinesin holoenzyme exists as a heterotetramer, consisting of two heavy chain and two light chain subunits. It is thought that one function of the light chains is to interact with the cargo. Alternative splicing of kinesin light chain pre-mRNA has been observed in lower organisms, although evidence for alternative splicing of the human gene has not been reported. We have identified 19 variants of the human KNS2 gene (KLC1) that are generated by alternative splicing of downstream exons, but calculate that KNS2 has the potential to produce 285919 spliceforms. Corresponding spliceforms of the mouse KLC1 gene were also identified. The alternative exons are all located 3' of exon 12 and the novel spliceforms produce both alternative carboxy termini and alternative 3' untranslated regions. The observation of multiple light chain isoforms is consistent with their proposed role in specific cargo attachment.