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For the full-automatic welding joint of X52 line steel, the welding process parameters were adjusted and optimized while fully considering the mutual influence of double torch and the influence of construction environment. Mechanical tests such as tensile test, bending test, nick break test, and hardness test were conducted to verify the reliability of the welding process, forming a welding process evaluation; At the same time, the problems encountered in on-site welding were analyzed and solved, and the key points for optimizing the welding process parameters of dual torch automatic welding were summarized, forming a full-automatic welding technology with copper backing for X52 pipeline steel. By conducting metallurgical analysis and hardness test on the weld seam, the distribution of the microstructure of the weld metal was analyzed from a microscopic perspective. The positive correlation between the hardness distribution of the X52 pipeline steel weld seam, heat affected zone, and base metal and the content of pearlite in the corresponding metallographic structure was obtained, further verifying the consistency of the metallographic structure of the weld metal and heat affected zone under the welding process conditions. The results indicated that the full-automatic welding process for copper liners could be applied to the welding of large diameter steel pipe, and the use of this process could significantly improved welding quality and efficiency. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid arthritis (RA) is a multifactorial systemic autoimmune disease characterized by ongoing synovial inflammation, leading to the degradation of cartilage. Cuproptosis, as a newly characterized form of cell death, may influence RA progression by regulating immune cells and chondrocytes. This study sets out to identify the hub cuproptosis‐related gene (CRG) associated with the pathogenesis of RA. Methods: A series of bioinformatic analyses were performed to evaluate the expression score of CRGs and the immune infiltration landscape between RA and normal samples. The hub gene was screened through the correlation analysis of CRGs, and the interaction network between the hub gene and transcription factors (TFs) was constructed. Finally, the hub gene was validated through quantitative real‐time polymerase chain reaction (qRT‐PCR) of patient samples and cell experiments. Results: Drolipoamide S‐acetyltransferase (DLAT) was screened as the hub gene. Correlation analysis between the hub gene and immune microenvironment demonstrated that DLAT had the highest correlation with T follicular helper cells. Eight pairs of DLAT–TF interaction networks were constructed. Single‐cell sequencing showed that CRGs were highly expressed in RA chondrocytes, and chondrocytes could be classified into three different subsets. qRT‐PCR was used to validate the above results. Dlat knockdown in immortalized human chondrocytes led to significantly improved mitochondrial membrane potentials and reduced levels of intracellular reactive oxygen species (ROS), mitochondrial ROS and apoptosis. Conclusions: This study rudimentarily demonstrates the correlation between CRGs and immune cell infiltration in RA. The biomarker DLAT may provide comprehensive insights into the pathogenesis and drug targets of RA. [ABSTRACT FROM AUTHOR]