954 resultados para thermochemical and structural correlations


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The objective of this work was to estimate the genetic parameters, genotypic and phenotypic correlations, and direct and indirect genetic gains among and within rubber tree (Hevea brasiliensis) progenies. The experiment was set up at the Municipality of Jaú, SP, Brazil. A randomized complete block design was used, with 22 treatments (progenies), 6 replicates, and 10 plants per plot at a spacing of 3x3 m. Three‑year‑old progenies were assessed for girth, rubber yield, and bark thickness by direct and indirect gains and genotypic correlations. The number of latex vessel rings showed the best correlations, correlating positively and significantly with girth and bark thickness. Selection gains among progenies were greater than within progeny for all the variables analyzed. Total gains obtained were high, especially for girth increase and rubber yield, which were 93.38 and 105.95%, respectively. Young progeny selection can maximize the expected genetic gains, reducing the rubber tree selection cycle.

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PURPOSE: To investigate the visual acuity results of eyes with neovascular age-related macular degeneration and refractory fluid despite monthly treatment with ranibizumab, and to investigate differences between refractory subretinal fluid and intraretinal cystic changes. METHODS: Retrospective chart review of consecutive treatment-refractory neovascular age-related macular degeneration, defined as persistent intraretinal or subretinal fluid despite monthly ranibizumab injections during 12 months or more. Data were evaluated for baseline characteristics, type and location of the refractory fluid, mean visual acuity change, number of injections, and the time point of first complete disappearance of all fluid on spectral domain optical coherence tomography. RESULTS: Seventy-six eyes (74 patients, mean age, 76.8 years) were identified. The mean follow-up was 33.6 months (range, 12-73 months). The mean number of injections was 11.4 in the first year and 27.7 over follow-up. The refractory fluid was located subfoveally in 61.8%. In 27 eyes (35.5%), the fluid resolved after a mean of 21.8 months (range, 13-49 months). Mean visual acuity increased by 9.0, 7.9, and 7.9 letters by Month 12, Month 24, and Month 36, respectively. Subgroup analysis revealed a higher risk for fibrosis (odds ratio, 3.30) or atrophy (odds ratio, 3.34) in patients with refractory cysts as compared with refractory subretinal fluid. Furthermore, refractory cysts showed a higher risk for a 10-letter visual acuity loss (P = 0.018). CONCLUSION: Fluid refractory to monthly treatment with ranibizumab for neovascular age-related macular degeneration still allowed for well-maintained visual improvement, even in subfoveal location. Late fluid resolution may occur. However, refractory cysts were associated with poorer anatomical and functional outcome than subretinal fluid.

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The effects of dark-induced stress on the evolution of the soluble metabolites present in senescent soybean (Glycine max L.) nodules were analysed in vitro using C-13- and P-31-NMR spectroscopy. Sucrose and trehalose were the predominant soluble storage carbons. During dark-induced stress, a decline in sugars and some key glycolytic metabolites was observed. Whereas 84% of the sucrose disappeared, only one-half of the trehalose was utilised. This decline coincides with the depletion of Gln, Asn, Ala and with an accumulation of ureides, which reflect a huge reduction of the N-2 fixation. Concomitantly, phosphodiesters and compounds like P-choline, a good marker of membrane phospholipids hydrolysis and cell autophagy, accumulated in the nodules. An autophagic process was confirmed by the decrease in cell fatty acid content. In addition, a slight increase in unsaturated fatty acids (oleic and linoleic acids) was observed, probably as a response to peroxidation reactions. Electron microscopy analysis revealed that, despite membranes dismantling, most of the bacteroids seem to be structurally intact. Taken together, our results show that the carbohydrate starvation induced in soybean by dark stress triggers a profound metabolic and structural rearrangement in the infected cells of soybean nodule which is representative of symbiotic cessation.

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Ample evidence indicates that inhibitory control (IC), a key executive component referring to the ability to suppress cognitive or motor processes, relies on a right-lateralized fronto-basal brain network. However, whether and how IC can be improved with training and the underlying neuroplastic mechanisms remains largely unresolved. We used functional and structural magnetic resonance imaging to measure the effects of 2 weeks of training with a Go/NoGo task specifically designed to improve frontal top-down IC mechanisms. The training-induced behavioral improvements were accompanied by a decrease in neural activity to inhibition trials within the right pars opercularis and triangularis, and in the left pars orbitalis of the inferior frontal gyri. Analyses of changes in brain anatomy induced by the IC training revealed increases in grey matter volume in the right pars orbitalis and modulations of white matter microstructure in the right pars triangularis. The task-specificity of the effects of training was confirmed by an absence of change in neural activity to a control working memory task. Our combined anatomical and functional findings indicate that differential patterns of functional and structural plasticity between and within inferior frontal gyri enhanced the speed of top-down inhibition processes and in turn IC proficiency. The results suggest that training-based interventions might help overcoming the anatomic and functional deficits of inferior frontal gyri manifesting in inhibition-related clinical conditions. More generally, we demonstrate how multimodal neuroimaging investigations of training-induced neuroplasticity enable revealing novel anatomo-functional dissociations within frontal executive brain networks. Hum Brain Mapp 36:2527-2543, 2015. © 2015 Wiley Periodicals, Inc.

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Classical Monte Carlo simulations were carried out on the NPT ensemble at 25°C and 1 atm, aiming to investigate the ability of the TIP4P water model [Jorgensen, Chandrasekhar, Madura, Impey and Klein; J. Chem. Phys., 79 (1983) 926] to reproduce the newest structural picture of liquid water. The results were compared with recent neutron diffraction data [Soper; Bruni and Ricci; J. Chem. Phys., 106 (1997) 247]. The influence of the computational conditions on the thermodynamic and structural results obtained with this model was also analyzed. The findings were compared with the original ones from Jorgensen et al [above-cited reference plus Mol. Phys., 56 (1985) 1381]. It is notice that the thermodynamic results are dependent on the boundary conditions used, whereas the usual radial distribution functions g(O/O(r)) and g(O/H(r)) do not depend on them.

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The synthesis and physico-chemical properties of new 6-acetylamino or 6-benzoyl-amino 2-benzylidene-4-methyl-4H-benzo[1,4]thiazin-3-ones and 6-benzoylamino or 6-nitro 2-benzylidene-4H-benzo[1,4]thiazin-3-ones are described. These benzylidene benzothiazine compounds were prepared by the Knoevenagel condensation with benzaldehydes. The configurations and conformations of benzylidene benzothiazine derivatives were optimised using the semi-empirical method AM1.

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Two food products (powders) were obtained by hot-air drying or lyophilisation methods on the whole guava fruits. The powders were characterised by sensory and thermal analyses (TGA-DSC), infrared spectroscopy (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Thermal, morphological and structural characterisations showed a similar behaviour for the two solids. TGA-DSC and IR showed the presence of pectin as the main constituent of solids. A semi-crystalline profile was evidenced by XRD, and lamellar/spherical morphologies were observed by SEM. Sensory analyses revealed an aroma highly related to guava. These value-added food products are an alternative to process guava and avoid loss during postharvest handling.

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In this Thesis I discuss the exact dynamics of simple non-Markovian systems. I focus on fundamental questions at the core of non-Markovian theory and investigate the dynamics of quantum correlations under non-Markovian decoherence. In the first context I present the connection between two different non-Markovian approaches, and compare two distinct definitions of non-Markovianity. The general aim is to characterize in exemplary cases which part of the environment is responsible for the feedback of information typical of non- Markovian dynamics. I also show how such a feedback of information is not always described by certain types of master equations commonly used to tackle non-Markovian dynamics. In the second context I characterize the dynamics of two qubits in a common non-Markovian reservoir, and introduce a new dynamical effect in a wellknown model, i.e., two qubits under depolarizing channels. In the first model the exact solution of the dynamics is found, and the entanglement behavior is extensively studied. The non-Markovianity of the reservoir and reservoirmediated-interaction between the qubits cause non-trivial dynamical features. The dynamical interplay between different types of correlations is also investigated. In the second model the study of quantum and classical correlations demonstrates the existence of a new effect: the sudden transition between classical and quantum decoherence. This phenomenon involves the complete preservation of the initial quantum correlations for long intervals of time of the order of the relaxation time of the system.

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This work is devoted to the study of the dynamical and structural properties of dendrimers. Different approaches were used: analytical theory, computer simulation results and experimental NMR studies. The theory of the relaxation spectrum of dendrimer macromolecules was developed. Relaxation processes which are manifest in the local orientational mobility of dendrimer macromolecules were established and studied in detail. Theoretical results and conclusions were used for experimental studies of carbosilane dendimers.

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ABSTRACT In Brazil, specifically in São Paulo State, there are guidelines based on the high diversity of tropical forests that instructs the restoration projects in the state (current SMA 32/2014). The main goal of this study was verify the importance and effectiveness of the high diversity of arboreal species originated from a reforestation, and its influence in a woody regenerating composition. We developed a phytosociologic study in a woody regenerating stratum of a nine year old reforestation at a Private Reserve of Natural Heritage (RPPN), in Mogi-Guaçu, São Paulo State. All specimens with height > 30 cm and Diameter at Breast Height (DBH) < 5 cm were evaluated. The woody regenerating diversity was smaller than the overstory diversity and the species composition was similar to the overstory. The Simpson index (1-D) was 0.85, Shannon index (H') was 2.46 and the Pielou index (J') was 0.60. The zoochoric dispersion syndrome was major among the species. Our results suggest that the use of high diversity of native seedlings in a reforestation leads to high diversity of species in woody regeneration stratum, after one decade of planting.