Identification of Key Genes Related to Immune Infiltration of Cirrhosis via Bioinformatics Analysis

BackgroundAccumulating researches have indicated that cirrhosis is a vital risk factor for morbidity and mortality worldwide. Nevertheless, the underlying immune-related molecular mechanism remains indistinct.MethodsGene expression profiles of GSE89377 and GSE139602 were investigated to identify differentially expressed genes (DEGs) related to cirrhosis. Enrichment analysis for DEGs was explored. CIBERSORT algorithm was used for evaluating DEGs immune infiltration. The String and Cytoscape database were utilized for analyses hub DEGs with a high tight connection, and the association between hub DEGs and immune cells infiltration was analyzed by Spearman method. Finally, the underlying molecular mechanism of the key DEGs was predicted via KEGG pathway analysis.ResultsIn all, 299 DEGs were attained among them 136 and 163 were up and down-regulated respectively. Then Enrichment function of DEGs and CIBERSORT algorithm showed that they are significant in immune and inflammatory responses. Four hub DEGs (ACTB, TAGLN, VIM, SOX9) were identified. Subsequently, the immune infiltration findings indicated that, the hub DEGs highly related immune cells. Finally, KEGGs pathways were predicted related with ACTB. ConclusionsThis study revealed key DEGs may implement inflammatory immune responses with cirrhosis, which could be used as biomarkers or therapeutic targets.

Research on Extended Finite Element Method for Axisymmetric Electrostatic Field Based on Liquid Nitrogen with Bubbles

In this paper, the extended finite element method (XFEM) is first applied to account for the weak discontinuity of the axisymmetric electrostatic field. Firstly, the interface between two materials in an element is described by the level set method. The enrichment function is used to modify the shape function of enrichment elements. Secondly, to illustrate the feature of the enrichment function, the distribution diagrams of enrichment functions in sub-elements are drawn. The 3D field can be simplified to an axisymmetric field, which can reduce the difficulty of calculation. Finally, models with bubbles in liquid nitrogen in the axisymmetric field are used to prove the reliability of XFEM. Compared with the conventional finite element method (CFEM), XFEM costs lower computing resources with almost the same computational accuracy.

Peridynamics boundary condition treatments via the pseudo-layer enrichment method and variable horizon approach

Peridynamics is a nonlocal theory that applies an integral term to represent the material response. Without a spatial differential term involved, peridynamics possesses certain advantages for solving discontinuity-involved problems. However, due to the reduction of stiffness, the deformation near the boundary region by peridynamics has a low accuracy compared to the local elastic deformation. Previous peridynamics boundary condition treatment enriches the stiffness on the boundary region by adding an artificial layer outside the domain boundary. However, this requires the deformation of the pseudo-layer to be pre-determined. In addition, the accuracy of the response on the physical domain depends largely on the accuracy of the pre-determined deformation on the pseudo-layer. Considering the fact that peridynamics reduces to local elasticity as the horizon size goes to zero, and previous researches indicate the potential advantage of boundary enrichment via the horizon varying approach, in this paper, peridynamics with a variable horizon is utilized as an efficient way to reduce the boundary-induced inaccuracy. Firstly, the pseudo-layer boundary condition treatments are discussed by using the symmetrical enrichment function and other extrapolation functions. Then, the variable horizon boundary condition treatment is introduced and a robust improvement of deformation accuracy on the boundary region is observed compared to other boundary condition treatments for both one- and two-dimensional examples. The variable horizon approach requires no additional pseudo-layer and the boundary conditions are applied directly on the physical boundary. Thus, the variable horizon approach is easy to implement and its computational cost is reduced.

A Node Split Method for Crack Growth Problem

A node split method based on Partition-of-unity method and mesh modified has been developed for numerical simulation of crack growth. The crack tip could be represented by the enrichment function based on Partition-of-unity method. The crack besides the tip always locates on the edge of element by moving the nodes around crack, and the continuity of crack could be kept on. For an example of 2D quadrilateral mesh, mesh processing has been presented on different condition. The simulation results indicate that applying the node split method to simulate crack growth problem can achieve relatively good results even for sparse grid.