Pathogenic mechanisms and potential therapeutic targets for Parkinson disease revealed by bioinformatic analysis of necroptosis and immune cell infiltration.

Parkinson disease (PD) is an age-dependent neurodegenerative disease with very high prevalence by age 80 years. Necroptosis is a newly identified form of programmed cell death implicated in neurodegenerative diseases, but has not yet been conclusively associated with PD. This study examined the contributions of necroptosis to PD using bioinformatics analysis. Datasets GSE26927, GSE49036, and GSE54536 from the gene expression omnibus database were analyzed for differentially expressed genes (DEGs). These DEGs were then subjected to gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis to identify associated functions and signaling mechanisms. Necroptosis-related differentially expressed genes (NRDEGs) were then identified by the overlap of DEGs and the necroptosis gene set hsa04217. The STRING database and Cytoscape software were then used to build and visualize a protein-protein interaction network and identify hubs and key functional modules among NRDEGs. In addition, immune cell type abundance was analyzed based on DEGs using ImmuCellAI. The identified DEGs, KEGG pathway enrichment terms, and protein-protein interaction network structures of NRDEGs were validated using an independent dataset (GSE54536). The necroptosis pathway was significantly enriched and activated in PD samples. Thirteen NRDEGs were identified in the GSE26927 and GSE49036 datasets, including receptor interacting serine/threonine kinase 1, CASP8 and FADD like apoptosis regulator, TNFRSF1A associated via death domain, and interleukin 1 beta, of which 6 were validated in the GSE54536 dataset. According to gene ontology and KEGG analyses, these NRDEGs are involved in necroptosis-related processes, apoptosis, B cell receptor signaling pathways, and NOD-like receptor signaling pathways. Analysis of DEGs also revealed significant increases in CD8 + T cell and Tex cell infiltration and significant decreases in B cell and T gamma delta cell infiltration within the PD brain. Necroptosis pathways are active in PD and associated with immune cell infiltration. The factors controlling necroptotic signaling and immune infiltration identified in this study may be valuable diagnostic markers and therapeutic targets for PD.

An effective, green and mild deproteinization method for polysaccharides of Ruditapes philippinarum by attapulgite-based silk fibroin composite aerogel.

A large amount of protein impurity severely restricts the application of polysaccharides of Ruditapes philippinarum (PRP) in food and medicine. Moreover, the traditional Sevag deproteinization method always involves organic reagents. The purpose of this paper was to develop an effective, green and mild deproteinization method from PRP by attapulgite-based silk fibroin composite aerogel (ASA). Firstly, ASA was synthesized and applied to remove protein from PRP. Secondly, the deproteinization parameters were optimized with selectivity coefficient as index as follows: dose of ASA 1% and pH 7.0. Under these conditions, deproteinization ratio (Dr%), polysaccharide recovery ratio (Rr%) and selectivity coefficient (Kc) reached 79.44 ± 1.87%, 95.81 ± 2.95% and 18.95 ± 1.55, respectively. Next, the feasibility of ASA method was evaluated. As a result, ASA method not only achieved higher deproteinization efficiency in less time compared with Sevag method, but also retained structure and antioxidant activity of polysaccharides. ASA was also proven with recycling ability and could be reused more than five times. Furthermore, it was found that protein adsorption on ASA was better fitted by pseudo second-order kinetic and Freundlich model. Taking together, the data implied that ASA method would be promising of deproteinization from PRP suitable for polysaccharides processing.

Effect of Surface Ultrasonic Rolling Treatment on Rolling Contact Fatigue Life of D2 Wheel Steel.

A GPM-30 fatigue machine was used to investigate the influence of surface ultrasonic rolling (SURT) on the rolling contact fatigue (RCF) life of D2 wheel steel. The experimental results present that the RCF life of the grinding processing sample is 4.1 × 105 cycles. During the RCF process, the flaking of the fine grain layer and high surface roughness of the grinding processing sample cause the production of RCF cracks. When the samples are treated by SURT with 0.2 MPa and 0.4 MPa, the RCF life is 9.2 × 105 cycles and 9.6 × 105 cycles, respectively. After SURT, the surface roughness of the samples is reduced, and a certain thickness of gradient-plastic-deformation layer and a residual-compressive-stress layer are produced. These factors lead to the improvement of the RCF property. However, when the static pressure increases to 0.6 MPa during SURT, the RCF life of the sample is reduced during RCF testing. The micro-cracks, which are formed during SURT, become the crack source and cause the formation of RCF cracks, decreasing of the RCF life.