983 resultados para PLC-8 characterization
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The influence of some process variables on the productivity of the fractions (liquid yield times fraction percent) obtained from SCFE of a Brazilian mineral coal using isopropanol and ethanol as primary solvents is analyzed using statistical techniques. A full factorial 23 experimental design was adopted to investigate the effects of process variables (temperature, pressure and cosolvent concentration) on the extraction products. The extracts were analyzed by the Preparative Liquid Chromatography-8 fractions method (PLC-8), a reliable, non destructive solvent fractionation method, especially developed for coal-derived liquids. Empirical statistical modeling was carried out in order to reproduce the experimental data. Correlations obtained were always greater than 0.98. Four specific process criteria were used to allow process optimization. Results obtained show that it is not possible to maximize both extract productivity and purity (through the minimization of heavy fraction content) simultaneously by manipulating the mentioned process variables.
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Objective: This paper presents a detailed study of fractal-based methods for texture characterization of mammographic mass lesions and architectural distortion. The purpose of this study is to explore the use of fractal and lacunarity analysis for the characterization and classification of both tumor lesions and normal breast parenchyma in mammography. Materials and methods: We conducted comparative evaluations of five popular fractal dimension estimation methods for the characterization of the texture of mass lesions and architectural distortion. We applied the concept of lacunarity to the description of the spatial distribution of the pixel intensities in mammographic images. These methods were tested with a set of 57 breast masses and 60 normal breast parenchyma (dataset1), and with another set of 19 architectural distortions and 41 normal breast parenchyma (dataset2). Support vector machines (SVM) were used as a pattern classification method for tumor classification. Results: Experimental results showed that the fractal dimension of region of interest (ROIs) depicting mass lesions and architectural distortion was statistically significantly lower than that of normal breast parenchyma for all five methods. Receiver operating characteristic (ROC) analysis showed that fractional Brownian motion (FBM) method generated the highest area under ROC curve (A z = 0.839 for dataset1, 0.828 for dataset2, respectively) among five methods for both datasets. Lacunarity analysis showed that the ROIs depicting mass lesions and architectural distortion had higher lacunarities than those of ROIs depicting normal breast parenchyma. The combination of FBM fractal dimension and lacunarity yielded the highest A z value (0.903 and 0.875, respectively) than those based on single feature alone for both given datasets. The application of the SVM improved the performance of the fractal-based features in differentiating tumor lesions from normal breast parenchyma by generating higher A z value. Conclusion: FBM texture model is the most appropriate model for characterizing mammographic images due to self-affinity assumption of the method being a better approximation. Lacunarity is an effective counterpart measure of the fractal dimension in texture feature extraction in mammographic images. The classification results obtained in this work suggest that the SVM is an effective method with great potential for classification in mammographic image analysis.
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Plants are sessile organisms and have evolved to tolerate a constantly changing environment. After the onset of different stress conditions, calcineurin B-like (CBL) proteins can sense calcium signals and activate CBL-interacting protein kinase (CIPK) proteins, which can phosphorylate downstream proteins to reestablish plant homeostasis. Previous studies in the bioenergy crop sugarcane showed that the ScCIPK8 gene is induced by drought stress and is also related to sucrose content. Here, we have characterized the protein-protein interactions of ScCIPK8 with six CBL proteins (ScCBL1, ScCBL2, ScCBL3, ScCBL6, ScCBL9, and ScCBL10). Yeast two-hybrid assays showed that ScCIPK8 interacts with ScCBL1, ScCBL3, and ScCBL6. Bimolecular fluorescence complementation assays confirmed in planta the interactions that were observed in yeast cells. These findings give insights on the regulatory networks related to sugar accumulation and drought stress responses in sugarcane.
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In this work, Ti(92)B(8) alloy was processed via rapid solidification (splat-cooling) and then heat-treated at 700 degrees C and 1000 degrees C. A careful microstructural characterization indicated that, after rapid solidification, a very fine two-phase microstructure was produced with no significant saturation of B in alpha/beta Ti. There was no indication of amorphous formation in the rapidly solidified splats. Both alpha Ti and TiB were observed in the microstructures of the splats after heat-treatment at 700 degrees C and 1000 degrees C, confirming the stability of the alpha Ti+TiB two-phase region in this temperature range. (C) 2008 Elsevier Inc. All rights reserved.
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Gene therapy approaches using recombinant adeno-associated virus serotype 2 (rAAV2) and serotype 8 (rAAV8) have achieved significant clinical benefits. The generation of rAAV Reference Standard Materials (RSM) is key to providing points of reference for particle titer, vector genome titer, and infectious titer for gene transfer vectors. Following the example of the rAAV2RSM, here we have generated and characterized a novel RSM based on rAAV serotype 8. The rAAV8RSM was produced using transient transfection, and the purification was based on density gradient ultracentrifugation. The rAAV8RSM was distributed for characterization along with standard assay protocols to 16 laboratories worldwide. Mean titers and 95% confidence intervals were determined for capsid particles (mean, 5.50×10(11) pt/ml; CI, 4.26×10(11) to 6.75×10(11) pt/ml), vector genomes (mean, 5.75×10(11) vg/ml; CI, 3.05×10(11) to 1.09×10(12) vg/ml), and infectious units (mean, 1.26×10(9) IU/ml; CI, 6.46×10(8) to 2.51×10(9) IU/ml). Notably, there was a significant degree of variation between institutions for each assay despite the relatively tight correlation of assay results within an institution. This outcome emphasizes the need to use RSMs to calibrate the titers of rAAV vectors in preclinical and clinical studies at a time when the field is maturing rapidly. The rAAV8RSM has been deposited at the American Type Culture Collection (VR-1816) and is available to the scientific community.
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A novel bis(glycinato) copper(II) paradodecatungstate Na-8[{Cu(gly)(2)}(2)]-{H-2(H2W12O42)}] center dot 24H(2)O (1) has been synthesized under hydrothermal conditions. The crystal structure of 1 reveals an infinite one-dimensional chain along the [100] direction and is built from paradodecatungstate (H2W12O42)(10-) clusters joined through [Cu(gly)(2)] moieties. Parallel chains are interlinked by NaO6 octahedra to generate a two-dimensional network.
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Complex fac-[RuCl(3)(NO)(P-N)] (1) was synthesized from the reaction of [RuCl(3)(H(2)O)(2)(NO)] and the P-N ligand, o-[(N,N-dimethylamino)phenyl]diphenylphosphine) in refluxing methanol solution, while complex mer,trans-[RuCl(3)(NO)(P-N)] (2) was obtained by photochemical isomerization of (1) in dichloromethane solution. The third possible isomer mer, cis-[RuCl(3)(NO)(P-N)] (3) was never observed in direct synthesis as well as in photo-or thermal-isomerization reactions. When refluxing a methanol solution of complex (2) a thermally induced isomerization occurs and complex (1) is regenerated. The complexes were characterized by NMR ((31)P{(1)H}, (15)N{1H} and 1H), cyclic voltammetry, FTIR, UV-Vis, elemental analysis and X-ray diffraction structure determination. The (31)P{(1)H} NMR revealed the presence of singlet at 35.6 for (1) and 28.3 ppm for (2). The (1)H NMR spectrum for (1) presented two singlets for the methyl hydrogens at 3.81 and 3.13 ppm, while for (2) was observed only one singlet at 3.29 ppm. FTIR Ru-NO stretching in KBr pellets or CH(2)Cl(2) solution presented 1866 and 1872 cm(-1) for (1) and 1841 and 1860 cm(-1) for (2). Electrochemical analysis revealed a irreversible reduction attributed to Ru(II)-NO(+) -> Ru(II)-NO(0) at -0.81 V and -0.62 V, for (1) and (2), respectively; the process Ru(II) -> Ru(III), as expected, is only observed around 2.0 V, for both complexes. Studies were conducted using (15)NO and both complexes were isolated with (15)N-enriched NO. Upon irradiation, the complex fac-[RuCl(3)(NO)(P-N)] (1) does not exchange (14)NO by (15)NO, while complex mer, trans-[RuCl(3)(NO)(P-N)] (2) does. Complex mer, trans-[RuCl(3)((15)NO)(P-N)] (2`) was obtained by direct reaction of mer, trans-[RuCl(3)(NO)(P-N)] (2) with (15)NO and the complex fac-[RuCl(3)((15)NO)(P-N)] (1`) was obtained by thermal-isomerization of mer, trans-[RuCl(3)((15)NO)(P-N)] (2`). DFT calculation on isomer energies, electronic spectra and electronic configuration were done. For complex (1) the HOMO orbital is essentially Ru (46.6%) and Cl (42.5%), for (2) Ru (57.4%) and Cl (39.0%) while LUMO orbital for (1) is based on NO (52.9%) and is less extent on Ru (38.4%), for (2) NO (58.2%) and Ru (31.5%). (C) 2011 Elsevier B. V. All rights reserved.
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The crystal structure of the title compound, a promising ligand for chelatoterapies in the treatment of Alzheimer`s disease, has been determined by single crystal X-ray diffractometry. The compound crystallized in the monoclinic space group C2/c with Z = 4. The dimeric 8-quinolinol molecule is sited on a crystallographic twofold axis passing through the CH(2) carbon atom that links the symmetry related molecular halves, giving rise to a two-bladed propeller-like conformation. The (1)H and (13)C NMR as well as the IFT-IR and Raman spectra of the compound were also recorded and are briefly discussed. Some comparisons with spectra of related species are made. (C) 2008 Elsevier B.V. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We describe a female patient with developmental delay, dysmorphic features and multiple congenital anomalies who presented a normal G-banded karyotype at the 550-band resolution. Array and multiplex-ligation probe amplification (MLPA) techniques identified an unexpected large unbalanced genomic aberration: a 17.6 Mb deletion of 9p associated to a 14.8 Mb duplication of 20p. The deleted 9p genes, especially CER1 and FREM1, seem to be more relevant to the phenotype than the duplicated 20p genes. This study also shows the relevance of using molecular techniques to make an accurate diagnosis in patients with dysmorphic features and multiple anomalies suggestive of chromosome aberration, even if on G-banding their karyotype appears to be normal. Fluorescence in situ hybridization (FISH) was necessary to identify a masked balanced translocation in the patient's mother, indicating the importance of associating cytogenetic and molecular techniques in clinical genetics, given the implications for patient management and genetic counseling. (C) 2012 Elsevier B.V. All rights reserved.
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A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) from Streptomyces antibioticus has been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space group P222, with unit-cell parameters a = 41.26, b = 51.86, c= 154.78 A. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 A resolution.
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The inducible nitric oxide synthase (iNOS) contains an amino-terminal oxygenase domain, a carboxy-terminal reductase domain, and an intervening calmodulin-binding region. For the synthesis of nitric oxide (NO), iNOS is active as a homodimer. The human iNOS mRNA is subject to alternative splicing, including deletion of exons 8 and 9 that encode amino acids 242–335 of the oxygenase domain. In this study, iNOS8−9− and full-length iNOS (iNOSFL) were cloned from bronchial epithelial cells. Expression of iNOS8−9− in 293 cell line resulted in generation of iNOS8−9− mRNA and protein but did not lead to NO production. In contrast to iNOSFL, iNOS8−9− did not form dimers. Similar to iNOSFL, iNOS8−9− exhibited NADPH-diaphorase activity and contained tightly bound calmodulin, indicating that the reductase and calmodulin-binding domains were functional. To identify sequences in exons 8 and 9 that are critical for dimerization, iNOSFL was used to construct 12 mutants, each with deletion of eight residues in the region encoded by exons 8 and 9. In addition, two “control” iNOS deletion mutants were synthesized, lacking either residues 45–52 of the oxygenase domain or residues 1131–1138 of the reductase domain. Whereas both control deletion mutants generated NO and formed dimers, none of the 12 other mutants formed dimers or generated NO. The region encoded by exons 8 and 9 is critical for iNOS dimer formation and NO production but not for reductase activity. This region could be a potential target for therapeutic interventions aimed at inhibiting iNOS dimerization and hence NO synthesis.