Gastric adenocarcinoma and Helicobacter pylori: Correlation with p53 mutation and p27 immunoexpression

Introduction: Helicobacter pylori infection is an established risk factor for gastric cancer development, but the exact underlying mechanism still remains obscure. The inactivation of tumor suppressor genes such as p53 and p27(KIP1) is a hypothesized mechanism, although there is no consensus regarding the influence of H. pylori cagA(+) in the development of these genetic alterations. Goals: To verify the relationship among H. pylori infection, p53 mutations and p27(Kip1) Protein (p27) expression in gastric adenocarcinomas (GA) seventy-four tissues were assayed by PCR for H. pylori and cagA presence. Mutational analysis of p53 gene was performed by single-strand conformation polymorphism (SSCP). Seventy tissues were analyzed by an immunohistochemical method for p27 expression. Results: From the samples examined, 95% (70/74) were H. pylori positive, 63% cagA(+). Altered p53 electrophoretic mobility was found in 72% of cases and significantly more frequent in the presence of cagA. Considerable reduction in p27 expression (19%) was found with a tendency for association between cagA(+) and p27(-), although the results were not statistically significant. Concomitant alterations of both suppressor genes were detected in 60% of cases. In the cases cagA(+), 66.7% of them had these concomitant alterations. Conclusions: The data suggest that H. pylori cagA(+) contributes to p53 alteration and indicate that concomitant gene inactivation, with reduced p27 expression, may be a mechanism in which H. pylori can promote the development and progression of gastric cancer. (C) 2010 Elsevier Ltd. All rights reserved.

Characterization of Si : O : C : H films fabricated using electron emission enhanced chemical vapour deposition

Silicon-based polymers and oxides may be formed when vapours of oxygen-containing organosilicone compounds are exposed to energetic electrons drawn from a hot filament by a bias potential applied to a second electrode in a controlled atmosphere in a vacuum chamber. As little deposition occurs in the absence of the bias potential, electron impact fragmentation is the key mechanism in film fabrication using electron-emission enhanced chemical vapour deposition (EEECVD). The feasibility of depositing amorphous hydrogenated carbon films also containing silicon from plasmas of tetramethylsilane or hexamethyldisiloxane has already been shown. In this work, we report the deposition of diverse films from plasmas of tetraethoxysilane (TEOS)-argon mixtures and the characterization of the materials obtained. The effects of changes in the substrate holder bias (Vs) and of the proportion of TEOS in the mixture (XT) on the chemical structure of the films are examined by infrared-reflection absorption spectroscopy (IRRAS) at near-normal and oblique incidence using unpolarised and p-polarised, light, respectively. The latter is particularly useful in detecting vibrational modes not observed when using conventional near-normal incidence. Elemental analyses of the film were carried out by X-ray photoelectron spectroscopy (XPS), which was also useful in complementary structural investigations. In addition, the dependencies of the deposition rate on Vs and XT are presented. (c) 2007 Elsevier B.V. All rights reserved.

Structure, ferroelectric/magnetoelectric properties and leakage current density of (Bi0.85Nd0.15)FeO3 thin films

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On the meaning of the minimal Wess-Zumino term

The physical meaning of the recently proposed minimal Wess-Zumino (MWZ) term is discussed. It is shown that the only relativistically acceptable MWZ corresponds to a gauged Floreanini-Jackiw chiral boson. This leads to the conclusion that the very mechanism in action is that of closing families like it happens in the standard model, and not that of the WZ term, in the spirit of Faddeev-Shatashvilli.

Relations between two-dimensional models from dimensional reduction

In this work we explore the consequences of dimensional reduction of the 3D Maxwell-Chern-Simons and some related models. A connection between topological mass generation in 3D and mass generation according to the Schwinger mechanism in 2D is obtained. In addition, a series of relationships is established by resorting to dimensional reduction and duality interpolating transformations. Non-Abelian generalizations are also pointed out.

Sintering and mass transport features of (Sn,Ti)O2 polycrystalline ceramics

Different (Sn,Ti)O2 compositions were sintered at 1450 °C for 2 h with the purpose of investigating their sintering and mass transport properties. Highly dense ceramics were obtained and their structural properties studied by X-ray diffraction and scanning electron microscopy. The changes in lattice parameters were analyzed by the Rietveld method and two mass transport mechanisms were observed during sintering in different temperature ranges, evidenced by the linear shrinkage rate as a function of temperature. The effect of the concentration of TiO2 on mass transport and densiffication during sintering was analyzed by considering the intrinsic defects. System densiffication was attributed to a mass transport mechanism in the SnO2 matrix, caused by the presence of TiO2, which formed a solid solution phase. The change in the mass transport mechanism was attributed to chemical bonding between SnO2 and TiO2, which improves ionic difusion as the concentration of TiO2 increased in (Sn,Ti)O2 compositions. © 2002 Elsevier Science Ltd. All rights reserved.

Quintessential inflation and non-oscillatory reheating model

A numerical study of the non-oscillatory reheating mechanism in a quintessential inflation context shows that high reheating temperature can be achieved compared with the usual reheating mechanism in which particles are produced gravitationally. We find that even for a very small coupling between the inflaton field and a massless scalar field, the non-oscillatory reheating production of particles dominates over the gravitational production mechanism. © 2004 Published by Elsevier B.V.

Traffic flow breakdown prediction using feature reduction through Rough-Neuro fuzzy Networks

The prediction of the traffic behavior could help to make decision about the routing process, as well as enables gains on effectiveness and productivity on the physical distribution. This need motivated the search for technological improvements in the Routing performance in metropolitan areas. The purpose of this paper is to present computational evidences that Artificial Neural Network ANN could be use to predict the traffic behavior in a metropolitan area such So Paulo (around 16 million inhabitants). The proposed methodology involves the application of Rough-Fuzzy Sets to define inference morphology for insertion of the behavior of Dynamic Routing into a structured rule basis, without human expert aid. The dynamics of the traffic parameters are described through membership functions. Rough Sets Theory identifies the attributes that are important, and suggest Fuzzy relations to be inserted on a Rough Neuro Fuzzy Network (RNFN) type Multilayer Perceptron (MLP) and type Radial Basis Function (RBF), in order to get an optimal surface response. To measure the performance of the proposed RNFN, the responses of the unreduced rule basis are compared with the reduced rule one. The results show that by making use of the Feature Reduction through RNFN, it is possible to reduce the need for human expert in the construction of the Fuzzy inference mechanism in such flow process like traffic breakdown. © 2011 IEEE.

A psicologia do ego de ernst kris e seu legado para a psicanálise da arte

This article intends to discuss the importance of the ego-psychology towards the psychoanalytical interpretation of the aesthetic experience. Its focus is based on the Ernst Kris original work, therefore it intends to present certain basis of his aesthetical thinking. In this case, however, it will suggest one certain reading which emphasizes the problem of sublimation as a drive destination-and not as a defense mechanism-in within this relationship between art and psychoanalysis; hence, it brings out a phenomenon that crosses the psychoanalytical thinking since its first conception.

Awaking the vacuum with spheroidal shells

It has been shown that well-behaved spacetimes may induce the vacuum fluctuations of some nonminimally coupled free scalar fields to go through a phase of exponential growth. Here, we discuss this mechanism in the context of spheroidal thin shells emphasizing the consequences of deviations from spherical symmetry. © 2013 American Physical Society.

Structure and kinetics of formation of APTS/GPTS-derived organic/inorganic hybrids

The structure and the kinetics of formation of APTS/GPTS-derived organic/inorganic hybrids were studied in situ by small-angle-X-ray scattering. The data were interpreted in terms of a process of primary particles formation and growth of mass-fractal clusters. At the very early stage, the population of the nonfractal primary particles (D = 3) increases with time. As the mass-fractal clusters appear (D < 3) as a result of the aggregation process, the radius of gyration, Rg, of the clusters increases on average. At advanced stages of aggregation, the clusters grow in a mechanism in which the number of particles per clusters increases while the number of clusters diminishes with time, in such a way that the correlation volume of the clusters, Vc, fulfills the relationship Vc â̂ R g D, in agreement with a mass-fractal character of the clusters. These results supporting a cluster-cluster aggregation process, together with the typically very low value found for the mass-fractal dimension D, are in favor of a diffusion-controlled cluster aggregation mechanism. © 2013 American Chemical Society.

Participação da ORF XAC3629 na regulação do operon de resistência a cobre copAB em Xanthomonas citri subsp. citri

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CD95 (FAS) e CD178 (FASL) induzem apoptose em células CD4+ E CD8+ do sangue periférico e esplênicas em cães naturalmente infectados por Leishmania spp: Kathlenn Liezbeth Oliveira Silva. -

Pós-graduação em Ciência Animal - FMVA

Infecção pela Leishmania chagasi: papel dos receptores Toll-like 2 e 4 alterações genotóxicas em camundongos BALB/c

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mecanismos sulcadores de semeadora-adubadora na cultura do milho (Zea mays L.) no sistema de plantio direto

Pós-graduação em Agronomia (Energia na Agricultura) - FCA