48 resultados para Sugawara, Michizane, 845-903.
Resumo:
Extra virgin olive oil is rich in phenolic compounds which are believed to exert beneficial effects against many pathological processes, including the development of colon cancer. We show that one of the major polyphenolic constituents of extra virgin olive oil, hydroxytyrosol (HT), exerts strong anti-proliferative effects against human colon adenocarcinoma cells via its ability to induce a cell cycle block in G2/M. These antiproliferative effects were preceded by a strong inhibition of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and a downstream reduction of cyclin D I expression, rather than by inhibition of p38 activity and cyclooxygenase-2 (COX-2) expression. These findings are of particular relevance due to the high colonic concentration of HT compared to the other olive oil polyphenols and may help explain the inverse link between colon cancer and olive oil consumption.
Resumo:
A whey salts mixture was used as a partial substitute for sodium chloride to provide a modified Na:K ratio (1:3.4) in the manufacture of white salted cheese using ultrafiltration. Reduction of chymosin addition from 20 to 8 mu L kg(-1) of cheese was also investigated. Variation of salt and chymosin levels did not result in any significant differences in composition and physicochemical properties. The rates of proteolysis in terms of water-soluble nitrogen (WSN) and nitrogen soluble in 12% trichloroacetic acid (TCA-SN) were affected by chymosin levels but not by salt treatment. Urea-PAGE electrophoretic analysis of caseins from the cheeses manufactured using three levels of chymosin and two salt types showed that the hydrolysis of alpha(s1)-casein was higher than for beta-caseins but the differences between the cheeses were not significant (P > 0.05). The chymosin level did not have a significant effect (P > 0.05) on hardness and fracturability, suggesting that any variation in hardness due to the initial hydrolysis was being confounded by other variables. Cheeses including the whey salts product were harder and more fracturable (P < 0.01) than the cheese treated with NaCl only. Both hardness and fracturability values decreased (P < 0.05) over the maturation period. The scores for bitterness were low; neither the effects of salt nor chymosin levels were significant (P > 0.05). (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
Water-soluble cationic copolymers and hydrogels were synthesized by radical copolymerization of [2-(methacryloyloxy)ethyl]trimetilylammonium chloride (MADQUAT) and 2-hydroxyethylacrylate (HEA). The kinetics of copolymerization has been studied and the reactivity ratios were determined. It was found that MADQUAT exhibits higher reactivity in copolymerization. The complexation between linear MADQUAT-HEA and linear poly(acrylic acid) (PAA) has been studied in aqueous solutions at different pH. It results in the formation of insoluble polyelectrolyte complexes, whose composition and stability to aggregate depends on MADQUAT content in copolymers and pH. The hydrogels were synthesized by three-dimensional radical copolymerization of MADQUAT and HEA in the presence of a crosslinker. The effects of the feed mixture composition on yield and swelling properties of the hydrogels were studied. The interactions of these hydrogels with linear PAA result in formation of gel-polyelectrolyte complexes and contraction of the samples. It was found that the contraction depends on copolymer composition, PAA molecular weight, and solution pH. (c) 2006 Wiley Periodicals, Inc.
Resumo:
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.
Resumo:
2-[Methyl(2-methylphenyl)amino]ethanol undergoes an ortho-alkyllithiation reaction with n-butyllithium to lead to a new mixed benzyllithium−lithium alkoxide. This organolithium species reacts with PPh2Cl, with selective P−C bond formation, to afford the ligand 2-[methyl(2-((diphenylphosphino)methyl)phenyl)amino]ethanol L1. The coordination of the ligand L1 to copper(I) leads to the complex [Cu(L1)2](BF4), whose structure has been determined by an X-ray diffraction study. In the solid state, one of the ligands acts as a monodentate phosphine while the other adopts a tridentate P,N,O coordination mode. A variable-temperature 31P NMR study demonstrated the existence of an equilibrium between the two modes in solution, with a coalescence temperature of ca. 0 °C, indicating a double-hemilabile behavior for the nitrogen and the oxygen functions. L1 reacts with [Pd(Me)(Cl)(COD)] to give a dinuclear complex in which the ligand appears to behave as a bridging anionic P,O ligand. Such a complex could serve as a model for a key intermediate in the proposed mechanism for the homogeneous catalysis of the methoxycarbonylation of propyne by certain palladium(II) complexes containing P,N ligands. L1 can undergo a second ortho-alkylmetalation reaction with n-butyllithium which, after addition of PPh2Cl, provides the new ligand 2-{methyl[2-(bis(diphenylphosphino)methyl)phenyl]amino}ethanol (L2) in high yield.
Resumo:
d(ACGTACGT), C78H84N30O32P7.20H2O, Mr (DNA) = 2170, tetragonal, P43212 (No 96), a = 42.845 (1), b = 42.845(1), c = 24.804 (1) Å, V = 45532.5 (2) Å3, z = 8,(MoK) = 0.71069 Å,µ(MoK) = 0.10 mm-1, T = 295 K, R = 0.18 for 1994 unique reflections between 5.0 and 1.9 Å resolution. The self-complementary octanucleotide d(ACGTACGT)2 has been crystallized and its structure determined to a resolution of 1.9 Å. The asymmetric unit consists of a single strand of octamer with 20 water molecules. It is only the second example of an octanucleotide having terminal A·T base pairs whose structure has been determined by X-ray crystallography. The sequence adopts the modified A-type conformation found for all octanucleotide duplexes studied to date with the helix bent by approximately 15° and an average tilt angle of 0°. Unusually the data collection was carried out using a 3 kW molybdenum sealed-tube source. The conformational details are discussed in comparison with other closely related sequences.
Resumo:
The Seille Valley in eastern France was home to one of Europe’s largest Iron Age salt industries. Sedimentology, palynology and geochronology have been integrated within ongoing archaeological investigations to reconstruct the Holocene palaeoenvironmental history of the Seille Valley and to elucidate the human–environment relationship of salt production. A sedimentary model of the valley has been constructed from a borehole survey of the floodplain and pollen analyses have been undertaken to reconstruct the vegetation history. Alluvial records have been successfully dated using optically stimulated luminescence and radiocarbon techniques, thereby providing a robust chronological framework. The results have provided an insight into the development of favourable conditions for salt production and there is evidence in the sedimentary record to suggest that salt production may have taken place during the mid-to-late Bronze Age. The latter has yet to be identified in the archaeological record and targeted excavation is therefore underway to test this finding. The development of the Iron Age industry had a major impact on the hydrological regime of the valley and its sedimentological history, with evidence for accelerated alluviation arising from floodplain erosion at salt production sites and modification of the local fluvial regime due to briquetage accumulation on the floodplain. This research provides an important insight into the environmental implications of early industrial activities, in addition to advancing knowledge about the Holocene palaeoenvironmental and social history of this previously poorly studied region of France.
Resumo:
Aggression in young people has been associated with a bias towards attributing hostile intent to others; however, little is known about the origin of biased social information processing. The current study explored the potential role of peer contagion in the emergence of hostile attribution in adolescents. 134 adolescents were assigned to one of two manipulated ‘chat-room’ conditions, where they believed they were communicating with online peers (e-confederates) who endorsed either hostile or benign intent attributions. Adolescents showed increased hostile attributions following exposure to hostile e-confederates and reduced hostility in the benign condition. Further analyses demonstrated that social anxiety was associated with a reduced tendency to take on hostile peer attitudes. Neither gender nor levels of aggression influenced individual susceptibility to peer influence, but aggressive adolescents reported greater affinity with hostile e-confederates.
Assessing and understanding the impact of stratospheric dynamics and variability on the earth system
Resumo:
Advances in weather and climate research have demonstrated the role of the stratosphere in the Earth system across a wide range of temporal and spatial scales. Stratospheric ozone loss has been identified as a key driver of Southern Hemisphere tropospheric circulation trends, affecting ocean currents and carbon uptake, sea ice, and possibly even the Antarctic ice sheets. Stratospheric variability has also been shown to affect short term and seasonal forecasts, connecting the tropics and midlatitudes and guiding storm track dynamics. The two-way interactions between the stratosphere and the Earth system have motivated the World Climate Research Programme's (WCRP) Stratospheric Processes and Their Role in Climate (SPARC) DynVar activity to investigate the impact of stratospheric dynamics and variability on climate. This assessment will be made possible by two new multi-model datasets. First, roughly 10 models with a well resolved stratosphere are participating in the Coupled Model Intercomparison Project 5 (CMIP5), providing the first multi-model ensemble of climate simulations coupled from the stratopause to the sea floor. Second, the Stratosphere Historical Forecasting Project (SHFP) of WCRP's Climate Variability and predictability (CLIVAR) program is forming a multi-model set of seasonal hindcasts with stratosphere resolving models, revealing the impact of both stratospheric initial conditions and dynamics on intraseasonal prediction. The CMIP5 and SHFP model-data sets will offer an unprecedented opportunity to understand the role of the stratosphere in the natural and forced variability of the Earth system and to determine whether incorporating knowledge of the middle atmosphere improves seasonal forecasts and climate projections. Capsule New modeling efforts will provide unprecedented opportunities to harness our knowledge of the stratosphere to improve weather and climate prediction.
Resumo:
An Escherichia coli oligonucleotide microarray based on three sequenced genomes was validated for comparative genomic microarray hybridization and used to study the diversity of E. coli O157 isolates from human infections and food and animal sources. Among 26 test strains, 24 (including both Shiga toxin [Stx]-positive and -negative strains) were found to be related to the two sequenced E. coli O157:117 strains, EDL933 and Sakai. However, these strains showed much greater genetic diversity than those reported previously, and most of them could not be categorized as either lineage I or H. Some genes were found more often in isolates from human than from nonhuman sources; e.g., ECs1202 and ECs2976, associated with stx2AB and stx1AB, were in all isolates from human sources but in only 40% of those from nonhuman sources. Some (but not all) lineage I-specific or -dominant genes were also more frequently associated with isolates from human. The results suggested that it might be more effective to concentrate our efforts on finding markers that are directly related to infection rather than those specific to certain lineages. In addition, two Stx-negative O157 cattle isolates (one confirmed to be 117) were significantly different from other Stx-positive and -negative E. coli O157:117 strains and were more similar to MG1655 in their gene content. This work demonstrates that not all E. coli O157:117 strains belong to the same clonal group, and those that were similar to E. coli K-12 might be less virulent.
Resumo:
In this paper we consider the Brownian motion with jump boundary and present a new proof of a recent result of Li, Leung and Rakesh concerning the exact convergence rate in the one-dimensional case. Our methods are dierent and mainly probabilistic relying on coupling methods adapted to the special situation under investigation. Moreover we answer a question raised by Ben-Ari and Pinsky concerning the dependence of the spectral gap from the jump distribution in a multi-dimensional setting.
Resumo:
Revealing the evolution of well-organized social behavior requires understanding a mechanism by which collective behavior is produced. A well-organized group may be produced by two possible mechanisms, namely, a central control and a distributed control. In the second case, local interactions between interchangeable components function at the bottom of the collective behavior. We focused on a simple behavior of an individual ant and analyzed the interactions between a pair of ants. In an experimental set-up, we placed the workers in a hemisphere without a nest, food, and a queen, and recorded their trajectories. The temporal pattern of velocity of each ant was obtained. From this bottom-up approach, we found the characteristic behavior of a single worker and a pair of workers as follows: (1) Activity of each individual has a rhythmic component. (2) Interactions between a pair of individuals result in two types of coupling, namely the anti-phase and the in-phase coupling. The direct physical contacts between the pair of workers might cause a phase shift of the rhythmic components in individual ants. We also build up a simple model based on the coupled oscillators toward the understanding of the whole colony behavior.