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Increased Diffusion (increased + diffusion)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

White matter diffusion is higher in Binswanger disease than in idiopathic normal pressure hydrocephalus

ACTA NEUROLOGICA SCANDINAVICA, Issue 4 2009
M. Tullberg
Objectives,,, To explore diagnostic differences in periventricular white matter (PWM) and deep white matter (DWM) diffusion patterns in patients diagnosed with Binswanger disease (BD) and in patients diagnosed with probable idiopathic normal pressure hydrocephalus (INPH) using diffusion-weighted imaging (DWI). Materials and methods,,, Apparent diffusion coefficient (ADC) values were calculated in the PWM and DWM in patients with INPH (n = 14) and BD (n = 9) and in controls (n = 10) using an spin echo echo planar imaging single-shot diffusion sequence and region of interest (ROI) analysis. Results,,, Patients with BD had higher ADC values than patients with INPH in the PWM and DWM in the frontal and occipital regions (P < 0.05) and higher values than controls in the frontal PWM and DWM (P < 0.01). After shunt surgery, ADC values were reduced in the frontal PWM in patients with INPH (P < 0.05). Conclusions,,, Increased diffusion in the PWM and DWM in patients with BD may reflect irreversible breakdown of axonal integrity caused by the subcortical ischaemic vascular disease. By contrast, the normal white matter diffusion in patients with INPH indicates structurally intact axons, compatible with the reversibility of this disorder. DWI may be an important non-invasive diagnostic tool for differentiating between INPH and BD and identifying shunt responders and reversible brain damage in patients with INPH. However, the overlap between patients with INPH and BD in this study restricts the predictive value of the method. [source]

Nitric Oxide Plays a Crucial Role in the Development/Progression of Nonalcoholic Steatohepatitis in the Choline-Deficient, l-Amino Acid-Defined Diet-Fed Rat Model

ALCOHOLISM, Issue 2010
Koji Fujita
Background:, The pathogenesis of nonalcoholic steatohepatitis (NASH) is still unclear. Recently, the 2-hit hypothesis was proposed, in which nitric oxide production, representing oxidative stress, was proposed as a very important candidate for the second hit. Methods:, The total study period was 10 weeks. A total of 20 rats were randomly divided into 2 groups. Group 1 was administered the Choline-Deficient, l-Amino Acid-Defined diet to produce a NASH model, and Group 2 as control received the Choline-Sufficient, l-Amino Acid-defined diet. The blood and tissue concentrations of nitrate + nitrite were measured using the Griess reagent and the expression levels of inducible nitric oxide synthase (iNOS) proteins and mRNA was determined by Western blotting. Results:, In regard to nitric oxide (NO) and NO metabolites, there were significant differences in the blood (especially portal venous blood) as well as tissue (liver and visceral fat) concentrations between the 2 animal groups; the amounts of NO metabolites in the tissues were much higher in the NASH models. The level of nitrotyrosine was much markedly higher in the NASH models than in the controls. In regard to the tissue expression of iNOS a significant difference between the 2 groups was found in the visceral fat, especially in the mesenterium. Conclusions:, Based on these results, we hypothesize that the iNOS expression and NO levels in the visceral fat increase, with increased diffusion of NO and its metabolites into the liver, resulting in increased nitrotyrosine formation in the liver; this, in turn, induces inflammation, apoptosis, and fibrosis in the liver, which are one of the characteristic features of NASH. [source]

Arendt, Augustine And Evil

THE HEYTHROP JOURNAL, Issue 2 2000
David Grumett
The publication of Hannah Arendt's doctoral these Love and Saint Augustine forces reappraisal of the view that Arendt's concept of evil originates in her experience of totalitarianism and coverage of the Eichmann trial. Augustine's account of the original nature of evil in the contexts of ontology, society and divine providence in fact provides the basis for Arendt's analysis of the banality of evil in the individual, the social, and the political spheres. Augustine's internal and external mental triads moreover contribute to Arendt's own thinking-willing-judging triad and allow a clearer understanding of its dynamics. The fact that Arendt's analysis derives much of its power from her appropriation of Augustinian theological concepts suggests a need for the increased diffusion of theological concepts in political thought. [source]

Using a piecewise linear bottom to fit the bed variation in a laterally averaged, z -co-ordinate hydrodynamic model

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2004
XinJian Chen
Abstract In developing a 3D or laterally averaged 2D model for free-surface flows using the finite difference method, the water depth is generally discretized either with the z -co-ordinate (z -levels) or a transformed co-ordinate (e.g. the so-called , -co-ordinate or , -levels). In a z -level model, the water depth is discretized without any transformation, while in a , -level model, the water depth is discretized after a so-called , -transformation that converts the water column to a unit, so that the free surface will be 0 (or 1) and the bottom will be -1 (or 0) in the stretched co-ordinate system. Both discretization methods have their own advantages and drawbacks. It is generally not conclusive that one discretization method always works better than the other. The biggest problem for the z -level model normally stems from the fact that it cannot fit the topography properly, while a , -level model does not have this kind of a topography-fitting problem. To solve the topography-fitting problem in a laterally averaged, 2D model using z -levels, a piecewise linear bottom is proposed in this paper. Since the resulting computational cells are not necessarily rectangular looking at the x,z plane, flux-based finite difference equations are used in the model to solve the governing equations. In addition to the piecewise linear bottom, the model can also be run with full cells or partial cells (both full cell and partial cell options yield a staircase bottom that does not fit the real bottom topography). Two frictionless wave cases were chosen to evaluate the responses of the model to different treatments of the topography. One wave case is a boundary value problem, while the other is an initial value problem. To verify that the piecewise linear bottom does not cause increased diffusions for areas with steep bottom slopes, a barotropic case in a symmetric triangular basin was tested. The model was also applied to a real estuary using various topography treatments. The model results demonstrate that fitting the topography is important for the initial value problem. For the boundary value problem, topography-fitting may not be very critical if the vertical spacing is appropriate. Copyright © 2004 John Wiley & Sons, Ltd. [source]