916 resultados para electrical conductivity of poly(p-phenylene sulfide)
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BACKGROUND: An understanding of the mechanisms responsible for the development and maintenance of allergic inflammation and their clinical implications is needed to develop specific and successful treatment for allergy. OBJECTIVES: To characterize in vitro T-cell responses to Der p 2, one of the major allergens of house dust mite (HDM), and investigate potential correlations between clinical and laboratory parameters. METHODS: Forty-two patients monosensitized to HDM and 10 age-matched, healthy children were studied. Dendritic cells pulsed with Der p 2 were used to stimulate autologous CD14(-) cells. Der p 2-specific T-cell activation markers, proliferation, and cytokine production profiles were examined. RESULTS: Der p 2-specific T-cell activation markers, proliferation, and T(H)2 cytokine production were significantly higher in HDM patients compared with healthy controls. Moreover, a significant correlation between proliferation and T(H)2 cytokine production was observed. Within the allergic group, skin reaction to HDM was significantly stronger in patients with a Der p 2-specific T-cell response. Levels of HDM-specific IgE directly correlated with interleukin 5 and interleukin 13 levels and with skin prick test results and, ultimately, with the patient's family history of allergy. Furthermore, the presence of atopic march correlated with T-cell proliferation. CONCLUSION: We found that, in HDM patients, Der p 2-specific T(H)2 responses, promoted by autologous dendritic cells in vitro, correlate with clinical parameters.
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Lime and gypsum influence nutrient availability and uptake, as well as the content of organic acids in the aerial plant parts. These changes, quantified by plant analysis of soluble nutrients, may potentiate the effect of soil amendment, ensuring the sustainability of the no-tillage system. In this sense the effect of lime and gypsum surface application on the content of water-soluble nutrients in peanut and oat residues was evaluated. The experiment was conducted on an Oxisol in Botucatu (SP) in the growing seasons 2004/2005 and 2005/2006. It was arranged in a randomized block design in split plots with four replications, where lime rates represented the plots and presence or absence of gypsum application the subplots. Peanut was grown in summer and white oat in the winter in the entire experimental area. Gypsum applied to peanut increased soluble Ca only in the first season, due to the short period between product application and determination of soluble nutrient contents in the plant extract. Liming of peanut and oat increased soluble Ca, Mg, K contents, did not alter Cu content and reduced Zn, Mn and Fe contents in both years of cultivation. Gypsum on the other hand reduced the electrical conductivity of peanut (2004/2005 and 2005/2006) and white oat (2004/2005).
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The primary sensory neurons in mouse dorsal root ganglia consist of diversified subpopulations which express distinct phenotypic characteristics such as substance P or calbindin D-28k. To determine whether neuronal phenotypes are altered or not in in vitro cultures carried out in a defined synthetic medium, dissociated dorsal root ganglion cells from newborn mice were grown in the alpha-modified minimum essential medium either supplemented with 10% fetal calf serum or serum-free. About 80% of the neurons survived after 5 days of culture in both media, but only 35% or 65% were rescued after 12 days in serum-free or fetal calf serum supplemented medium, respectively. The neuronal subpopulations expressing substance P or calbindin D-28k displayed similar morphological properties in both media and a higher resistance to culture conditions than the whole neuronal cell population, especially in serum-free medium. It is therefore concluded that a defined synthetic medium offers reproducible conditions to culture dorsal root ganglion cells for at least 5 days, stimulates the expression of substance P and enriches preferentially neuronal phenotypes expressing substance P or calbindin D-28k, for a longer period of culture.
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An instrument designed to measure thermal conductivity of consolidated rocks, dry or saturated, using a transient method is presented. The instrument measures relative values of the thermal conductivity, and it needs calibration to obtain absolute values. The device can be used as heat pulse line source and as continuous heat line source. Two parameters to determine thermal conductivity are proposed: TMAX, in heat pulse line source, and SLOPE, in continuous heat line source. Its performance is better, and the operation simpler, in heat pulse line-source mode with a measuring time of 170 s and a reproducibility better than 2.5%. The sample preparation is very simple on both modes. The performance has been tested with a set of ten rocks with thermal conductivity values between 1.4 and 5.2 W m¿1 K¿1 which covers the usual range for consolidated rocks.
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Oxygen content is a very important factor influencing the electrical properties of YBa2Cu3Oy. In this work the electrical properties of laser deposited YBa2Cu3Oy thin films on LaAlO3(100), in the whole range 6 y 7, are studied. An electrical network model, which randomly assigns oxygen contents and R(T) characteristics to the different elements in the circuit according to an arbitrary distribution, is used to analyze several features in the measured R(T) characteristics as a function of oxygen homogeneity. The model takes into account both short-range and long-range oxygen inhomogeneities. Good agreement between estimated oxygen contents from x-ray diffraction data in our samples and the average oxygen contents used to reproduce their R(T) characteristics is found. The model points out that oxygen homogeneity is very important in order to get the best and reproducible properties, and for conduction and superconductivity analysis through the shape or derivatives of R(T) characteristics.
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The Mehlich-1 (M-1) extractant and Monocalcium Phosphate in acetic acid (MCPa) have mechanisms for extraction of available P and S in acidity and in ligand exchange, whether of the sulfate of the extractant by the phosphate of the soil, or of the phosphate of the extractant by the sulfate of the soil. In clayey soils, with greater P adsorption capacity, or lower remaining P (Rem-P) value, which corresponds to soils with greater Phosphate Buffer Capacity (PBC), more buffered for acidity, the initially low pH of the extractants increases over their time of contact with the soil in the direction of the pH of the soil; and the sulfate of the M-1 or the phosphate of the MCPa is adsorbed by adsorption sites occupied by these anions or not. This situation makes the extractant lose its extraction capacity, a phenomenon known as loss of extraction capacity or consumption of the extractant, the object of this study. Twenty soil samples were chosen so as to cover the range of Rem-P (0 to 60 mg L-1). Rem-P was used as a measure of the PBC. The P and S contents available from the soil samples through M-1 and MCPa, and the contents of other nutrients and of organic matter were determined. For determination of loss of extraction capacity, after the rest period, the pH and the P and S contents were measured in both the extracts-soils. Although significant, the loss of extraction capacity of the acidity of the M-1 and MCPa extractants with reduction in the Rem-P value did not have a very expressive effect. A “linear plateau” model was observed for the M-1 for discontinuous loss of extraction capacity of the P content in accordance with reduction in the concentration of the Rem-P or increase in the PBC, suggesting that a discontinuous model should also be adopted for interpretation of available P of soils with different Rem-P values. In contrast, a continuous linear response was observed between the P variables in the extract-soil and Rem-P for the MCPa extractor, which shows increasing loss of extraction capacity of this extractor with an increase in the PBC of the soil, indicating the validity of the linear relationship between the available S of the soil and the PBC, estimated by Rem-P, as currently adopted.
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Kasvualustana käytetyn heikosti maatuneen rahkaturpeen lämmönjohtavuus
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BACKGROUND: The P-type II ATPase gene family encodes proteins with an important role in adaptation of the cell to variation in external K+, Ca2+ and Na2+ concentrations. The presence of P-type II gene subfamilies that are specific for certain kingdoms has been reported but was sometimes contradicted by discovery of previously unknown homologous sequences in newly sequenced genomes. Members of this gene family have been sampled in all of the fungal phyla except the arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), which are known to play a key-role in terrestrial ecosystems and to be genetically highly variable within populations. Here we used highly degenerate primers on AMF genomic DNA to increase the sampling of fungal P-Type II ATPases and to test previous predictions about their evolution. In parallel, homologous sequences of the P-type II ATPases have been used to determine the nature and amount of polymorphism that is present at these loci among isolates of Glomus intraradices harvested from the same field. RESULTS: In this study, four P-type II ATPase sub-families have been isolated from three AMF species. We show that, contrary to previous predictions, P-type IIC ATPases are present in all basal fungal taxa. Additionally, P-Type IIE ATPases should no longer be considered as exclusive to the Ascomycota and the Basidiomycota, since we also demonstrate their presence in the Zygomycota. Finally, a comparison of homologous sequences encoding P-type IID ATPases showed unexpectedly that indel mutations among coding regions, as well as specific gene duplications occur among AMF individuals within the same field. CONCLUSION: On the basis of these results we suggest that the diversification of P-Type IIC and E ATPases followed the diversification of the extant fungal phyla with independent events of gene gains and losses. Consistent with recent findings on the human genome, but at a much smaller geographic scale, we provided evidence that structural genomic changes, such as exonic indel mutations and gene duplications are less rare than previously thought and that these also occur within fungal populations.
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In freshwater planarians, the protein TCEN49 has been linked to the regional specification of the central body region, which includes the pharynx.
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Intrusion of deicing materials and surface water into concrete bridge decks is a main contributor in deck reinforcing steel corrosion and concrete delamination. Salt, spread on bridge decks to melt ice, dissolves in water and permeates voids in the concrete deck. When the chloride content of the concrete in contact with reinforcing steel reaches a high enough concentration, the steel oxidizes. In Iowa, the method used to reduce bridge deck chloride penetration is the application of a low slump dense concrete overlay after the completion of all Class A and Class B floor repairs. A possible alternative to the use of dense concrete overlays, developed by Poly-Carb, Inc., is the MARK-163 FLEXOGRID Overlay System. FLEXOGRID is a two component system of epoxy and urethane which is applied on a bridge deck to a minimum thickness of ¼ inch. An aggregate mixture of silica quartz and aluminum oxide is broadcast onto the epoxy at a prescribed rate to provide deck protection and superior friction properties. The material is mixed on site and applied to the deck in a series of lifts (usually two) until the desired overlay thickness has been attained.
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In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies. In thin-film transistors this effect leads to a higher threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the fieldeffect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies.
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Lappeenrannan teknillisen korkeakoulun sähkötekniikan osasto muutti 1.8.2005 sähkötekniikan tutkinnon kaksiportaiseksi ja vastaamaan näin Bologna-prosessia ja Suomen yliopistolainsäädäntöä. Tutkinnonuudistuksen myötä osasto haluaa varmistaa sähkötekniikan tutkintojen laadun ja vertailtavuuden sekä parantaa opiskelijoidensekä henkilökunnan liikkuvuutta. Tutkintojen laatu ja vertailtavuus osoitetaan sähkötekniikan osaston benchmark-projektilla, jossa kerätään tietoja maisteri- ja tohtorintutkintoa tarjoavista eurooppalaisista yliopistoista. Diplomityö käsittää BM-projektin kolmannen vaiheen suunnittelun ja toteutuksen sisältäen teoriaa benchmark-projekteille tyypillisistä toimintatavoista. Hyväksi havaitut menetelmiä, kuten kyselyt ja matriisit, on tässä työssä otettu soveltuvin osin sähkötekniikan osaston BM-projektin työkaluiksi. Diplomityössä analysoidaan työkalujen avulla BM-kumppaneilta kerättyjä tietoja sekä esitetään ratkaisuja, miten sähkötekniikan osastolla voidaan jatkaa parhaiden toimintatapojen löytämistä.
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INTRODUCTION: In this study we investigated differences in the spatial recruitment of motor units (MUs) in the quadriceps when electrical stimulation is applied over the quadriceps belly versus the femoral nerve. METHODS: M-waves and mechanical twitches were evoked using over-the-quadriceps and femoral nerve stimulation of gradually increasing intensity from 22 young, healthy subjects. Spatial recruitment was investigated using recruitment curves of M-waves recorded from the vastus medialis (VM) and vastus lateralis (VL) and of twitches recorded from the quadriceps. RESULTS: At maximal stimulation intensity (Imax), no differences were found between nerve and over-the-quadriceps stimulation. At submaximal intensities, VL M-wave amplitude was higher for over-the-quadriceps stimulation at 40% Imax, and peak twitch force was greater for nerve stimulation at 60% and 80% Imax. CONCLUSIONS: For the VM, MU spatial recruitment during nerve and over-the-quadriceps stimulation of increasing intensity occurred in a similar manner, whereas significant differences were observed for the VL. Muscle Nerve, 2013.