32 research outputs found

    Controlled nucleation of topological defects in the stripe domain patterns of Lateral multilayers with Perpendicular Magnetic Anisotropy: competition between magnetostatic, exchange and misfit interactions

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    Magnetic lateral multilayers have been fabricated on weak perpendicular magnetic anisotropy amorphous Nd-Co films in order to perform a systematic study on the conditions for controlled nucleation of topological defects within their magnetic stripe domain pattern. A lateral thickness modulation of period ww is defined on the nanostructured samples that, in turn, induces a lateral modulation of both magnetic stripe domain periods λ\lambda and average in-plane magnetization component MinplaneM_{inplane}. Depending on lateral multilayer period and in-plane applied field, thin and thick regions switch independently during in-plane magnetization reversal and domain walls are created within the in-plane magnetization configuration coupled to variable angle grain boundaries and disclinations within the magnetic stripe domain patterns. This process is mainly driven by the competition between rotatable anisotropy (that couples the magnetic stripe pattern to in-plane magnetization) and in-plane shape anisotropy induced by the periodic thickness modulation. However, as the structural period ww becomes comparable to magnetic stripe period λ\lambda, the nucleation of topological defects at the interfaces between thin and thick regions is hindered by a size effect and stripe domains in the different thickness regions become strongly coupled.Comment: 10 pages, 7 figures, submitted to Physical Review

    [Bladder transitional cell carcinoma rating, systematization of grading and value of DNA ploidy]

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    <p>TCCs are an heterogenous group of tumors with an uncertain biologic behaviour, especially intermediate grade (G2). Histologic grade and pathologic stage have revealed only partially useful on predicting the outcome.<br>Search and statement of objective and cuantitative parameters able to define prognostic subgroups to TCCs.<br>We studied consecutive 106 patients with TCC in order to: 1) Identify every variable with independent predictive value in classifying cases of TCC in a three (1,2,3) or two (high/low) grades systems. 2) Make a correlation between DNA ploidy obtained by image analysis and DNA ploidy and S-phase obtained by flow cytometry.<br>Every variable used to define the histologic grade showed significative correlation with both gradation systems. In multivariate analysis, the presence of superficial cells and the mitotic counts revealed us the most valuable variables in predicting the histologic grade. DNA-ploidy (both obtained by static an flow cytometry) correlated well with grade, stage, growth pattern and necrosis, whereas S-phase did so with grade, mitotic index and DNA ploidy. Image cytometry showed similars results to those of flow cytometry and also was able to detect aneuploidy when an situ carcinoma or dysplasia were present in the adyacent mucosa.</p

    Distinct contributions of TNF receptor 1 and 2 to TNF-induced glomerular inflammation in mice

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    TNF is an important mediator of glomerulonephritis. The two TNF-receptors TNFR1 and TNFR2 contribute differently to glomerular inflammation in vivo, but specific mechanisms of TNFR-mediated inflammatory responses in glomeruli are unknown. We investigated their expression and function in murine kidneys, isolated glomeruli ex vivo, and glomerular cells in vitro. In normal kidney TNFR1 and TNFR2 were preferentially expressed in glomeruli. Expression of both TNFRs and TNF-induced upregulation of TNFR2 mRNA was confirmed in murine glomerular endothelial and mesangial cell lines. In vivo, TNF exposure rapidly induced glomerular accumulation of leukocytes. To examine TNFR-specific inflammatory responses in intrinsic glomerular cells but not infiltrating leukocytes we performed microarray gene expression profiling on intact glomeruli isolated from wildtype and Tnfr-deficient mice following exposure to soluble TNF ex vivo. Most TNF-induced effects were exclusively mediated by TNFR1, including induced glomerular expression of adhesion molecules, chemokines, complement factors and pro-apoptotic molecules. However, TNFR2 contributed to TNFR1-dependent mRNA expression of inflammatory mediators in glomeruli when exposed to low TNF concentrations. Chemokine secretion was absent in TNF-stimulated Tnfr1-deficient glomeruli, but also significantly decreased in glomeruli lacking TNFR2. In vivo, TNF-induced glomerular leukocyte infiltration was abrogated in Tnfr1-deficient mice, whereas Tnfr2-deficiency decreased mononuclear phagocytes infiltrates, but not neutrophils. These data demonstrate that activation of intrinsic glomerular cells by soluble TNF requires TNFR1, whereas TNFR2 is not essential, but augments TNFR1-dependent effects. Previously described TNFR2-dependent glomerular inflammation may therefore require TNFR2 activation by membrane-bound, but not soluble TNF
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