The leukoaraiosis is more prevalent in the large artery atherosclerosis stroke subtype among Korean patients with ischemic stroke

<p>Abstract</p> <p>Background</p> <p>Several studies have suggested that the specific stroke subtype may influence the presence of leukoaraiosis in patients with ischemic stroke. We investigated the association between stroke subtype and leukoaraiosis in Korean patients with ischemic stroke by MRI.</p> <p>Methods</p> <p>There were 594 patients included in this study that were classified as large artery disease, lacune and cardioembolic stroke. For large-artery disease, the analysis focused on the intracranial or extracranial location of the stenosis, and the multiplicity of the stenotic lesions. Leukoaraiosis grading was performed according to the Atherosclerosis Risk in Communities Study.</p> <p>Results</p> <p>There was a significant association between leukoaraiosis and the stroke subtypes; the large-artery-disease group had a higher prevalence of leukoaraiosis than did the other groups (55.4% in the large-artery-disease group, 30.3% in the lacunar group and 14.3% in the cardioembolic group, P = 0.016 by chi-square test). On the multivariate linear regression analysis, age, the presence of hypertension, previous stroke and stroke subtype were independently associated with the presence of leukoaraiosis. In the sub analysis of the large-artery-disease group, the leukoaraiosis had a tendency to be more prevalent in the mixed and intracranial stenosis group than did the extracranial stenosis group (45.5% in the mixed group, 40.3% in the intracranial group and 26.9% in the extracranial group, P = 0.08 by chi-square test).</p> <p>Conclusion</p> <p>The association of leukoaraiosis with large-artery disease in this study might be due to the relatively high prevalence of intracranial occlusive lesions in Korean stroke patients compared to other ethnic groups.</p

Wave instabilities in the presence of non vanishing background in nonlinear Schrodinger systems

We investigate wave collapse ruled by the generalized nonlinear Schroedinger (NLS) equation in 1+1 dimensions, for localized excitations with non-zero background, establishing through virial identities a new criterion for blow-up. When collapse is arrested, a semiclassical approach allows us to show that the system can favor the formation of dispersive shock waves. The general findings are illustrated with a model of interest to both classical and quantum physics (cubic-quintic NLS equation), demonstrating a radically novel scenario of instability, where solitons identify a marginal condition between blow-up and occurrence of shock waves, triggered by arbitrarily small mass perturbations of different sign

Circulating FGF21 Levels Are Progressively Increased from the Early to End Stages of Chronic Kidney Diseases and Are Associated with Renal Function in Chinese

Fibroblast growth factor 21 (FGF21) is a hepatic hormone involved in the regulation of lipid and carbohydrate metabolism. This study aims to test the hypothesis that elevated FGF21 concentrations are associated with the change of renal function and the presence of left ventricular hypertrophy (LVH) in the different stages of chronic kidney disease (CKD) progression.0.05).Plasma FGF21 levels are significantly increased with the development of early- to end-stage CKD and are independently associated with renal function and adverse lipid profiles in Chinese population. Understanding whether increased FGF21 is associated with myocardial hypertrophy in CKD requires further study

Relationship between Exercise Capacity and Brain Size in Mammals

A great deal of experimental research supports strong associations between exercise, cognition, neurogenesis and neuroprotection in mammals. Much of this work has focused on neurogenesis in individual subjects in a limited number of species. However, no study to date has examined the relationship between exercise and neurobiology across a wide range of mammalian taxa. It is possible that exercise and neurobiology are related across evolutionary time. To test this hypothesis, this study examines the association between exercise and brain size across a wide range of mammals.Controlling for associations with body size, we examined the correlation between brain size and a proxy for exercise frequency and capacity, maximum metabolic rate (MMR; ml O(2) min(-1)). We collected brain sizes and MMRs from the literature and calculated residuals from the least-squares regression line describing the relationship between body mass and each variable of interest. We then analyzed the correlation between residual brain size and residual MMR both before and after controlling for phylogeny using phylogenetic independent contrasts. We found a significant positive correlation between maximum metabolic rate and brain size across a wide range of taxa.These results suggest a novel hypothesis that links brain size to the evolution of locomotor behaviors in a wide variety of mammalian species. In the end, we suggest that some portion of brain size in nonhuman mammals may have evolved in conjunction with increases in exercise capacity rather than solely in response to selection related to cognitive abilities

soliton interactions

We show that the spatial coherence of a partially incoherent light beam can be greatly enhanced through an energy-conserving interaction with an incoherent or a coherent dark spatial soliton. Computer simulations show that during this process a portion of the incoherent beam is trapped within the dark notch of the dark soliton, thus forming a sharp intensity spike. In this region the correlation length dramatically increases by at least 2 orders of magnitude. (C) 2000 Optical Society of America

noninstantaneous Kerr media

We investigate the coherence characteristics of multimode incoherent spatial solitons in noninstantaneous Kerr-like nonlinear media. Other properties of these incoherent solitons are also discussed as a function of their modal composition. [S1063-651X(99)04001-5]

Gray spatial solitons in biased photorefractive media

We provide a detailed analysis of gray spatial optical solitons in biased photorefractive media. The properties associated with these solitons, such as their transverse velocity, spatial width, and phase profile, are obtained as functions of their normalized intensity and degree of "grayness." By employing the stability criterion based on the renormalized field momentum, we investigate the stability regions of gray spatial photorefractive solitons. The process of the soliton Y splitting arising from an initially even field depression is quasi-analytically described by use of a Hamiltonian formalism. (C) 2001 Optical Society of America

Bright spatial solitons on a partially incoherent background

We present the first observation of incoherent antidark spatial solitons in noninstantaneous nonlinear media. This new class of soliton states involves bright solitons on a partially incoherent background of infinite extent. In the case where the nonlinearity is of the Kerr type, their existence is demonstrated analytically by means of an exact solution. Computer simulations and experiments indicate that these incoherent antidark solitons can propagate in a stable fashion provided that the spatial coherence of their background is reduced below the incoherent modulation instability threshold