Correlation of oxidative stress and vascular endothelial dysfunction with hippocampal perfusion in atrial fibrillation patients with cognitive impairment.

Objectives: To evaluate the correlation of oxidative stress and vascular endothelial dysfunction with hippocampal perfusion in patients with atrial fibrillation and cognitive impairment. Methods: In total, 41 atrial fibrillation patients with cognitive impairment were compared to 45 atrial fibrillation patients without cognitive impairment. Oxidative stress, vascular endothelial dysfunction, hippocampal perfusion, and cognitive function were measured. Results: Serum level of oxidized low-density lipoprotein was significantly higher in the atrial fibrillation + cognitive impairment group than in the atrial fibrillation group. Serum levels of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were significantly higher, and nitric oxide was lower, in the atrial fibrillation + cognitive impairment group than in the atrial fibrillation group. The regional cerebral blood volume, mean transit time, and time to peak were significantly higher in the atrial fibrillation + cognitive impairment group than in the atrial fibrillation group. Moreover, regional cerebral blood flow was significantly lower in the atrial fibrillation + cognitive impairment group than in the atrial fibrillation group. Age, left atrial diameter, and regional cerebral blood volume were negatively correlated with the cognitive function score in the atrial fibrillation + cognitive impairment group. Serum levels of oxidized low-density lipoprotein, regional cerebral blood volume, regional cerebral blood flow, mean transit time, and time to peak were significantly correlated with cognitive impairment in atrial fibrillation patients after multivariate logistic regression analysis. Conclusion: Hippocampal perfusion and oxidative stress were significantly correlated with cognitive impairment in atrial fibrillation patients.

The Correlation of Inflammation, Oxidative Stress, and Hippocampal Perfusion in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) is closely related to abnormal cerebral blood flow. Inflammation and oxidative stress have always been important factors in the pathophysiology of AF. It remains unknown whether inflammation and oxidative stress are correlated to hippocampal perfusion in patients with AF.Sixty-three patients with AF with normal hippocampal blood perfusion (NHBP) were compared to 71 patients with AF with abnormal hippocampal blood perfusion (AHBP) using a case-control study design. The serum levels of inflammation and oxidative stress were measured. The hippocampal perfusion was detected. (1) The serum levels of high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and oxidized low-density lipoprotein (ox-LDL) were statistically higher in the AHBP group than in the NHBP group. In the AHBP subgroup analysis, the serum levels of hs-CRP and IL-6 were statistically higher in patients with persistent AF than those with paroxysmal AF. (2) The relative cerebral blood volume (rCBV), mean transit time (MTT), and the time-to-peak (TTP) were statistically higher in the AHBP group than in the NHBP group. Moreover, cerebral blood flow (rCBF) was statistically lower in the AHBP group than in the NHBP group. (3) relative cerebral blood volume (rCBV), rCBF, MTT, and TTP were passively associated with serum hs-CRP and IL-6; rCBV, rCBF, and MTT were positively associated with ox-LDL. The serum levels of hs-CRP, IL-6, and ox-LDL were associated with AHBP in patients with AF after multivariate logistic regression analysis.Oxidative stress and inflammatory biomarkers were increased in patients with AF with AHBP, in which the serum levels of hs-CRP and IL-6 in the persistent AF group were statistically higher than those in the paroxysmal AF group. The serum levels of hs-CRP, IL-6, and ox-LDL were associated with AHBP in patients with AF.

Microscopic Interface and Multiscale Failure Analysis of Proposed Molecular Chain Polymers Based on Aifantis Strain Gradient Theory.

A study on the microscopic morphology of real-world polymer blends and its mechanism of change showed that the microscopic morphology of equiproportional mixtures gradually changed from a dense body structure to a network structure with the addition of the total polymer concentration up to 20%; the microscopic morphology of mixtures with different proportions was characterized by the most uniform network structure of equiproportional mixtures when the total polymer concentration was 20%. The polymer acts as a defoamer in the mixed system. In this paper, the relationship between the microscopic morphology of each mixture and the physicochemical behavior of the two polymer chains in the mixed system was investigated on the basis of the Aifantis strain gradient theory. Molecular polymer microscopic interface and multiscale failure analysis are proposed. It is shown that for the dihedral angle distribution of four consecutive coarse-grained particles, the peaks obtained from all atomic-scale simulation data are reproduced in the coarse-grained model simulations. The deviation is within 2.5% in most places, except for the local area where the deviation exceeds 5%. Therefore, we have achieved good results for large-scale failures.