Search

Graded polycrystalline copper materials have been expected in the field of scientific research and engineering in recent years because the core of the material has enough toughness and a sufficient surface strength. However, the plastic deformation mechanism, gradient grain generation mechanism and material strengthening principle of polycrystalline copper are still not well understood. Therefore, it is urgent to further analyze the plastic deformation of polycrystalline copper. In this study, the micron scale plastic deformation behavior of polycrystalline copper is simulated based on the crystal plasticity finite element method. The simulation analysis is carried out from the aspects of grain size, grain shape, crystal orientation type and quantity, loading mode and so on. The effects of the above parameters on the Mises stress nephogram and stress-strain curve of polycrystalline copper were analyzed. At the end of the article, the EBSD orientation distribution information of graded polycrystalline copper grains obtained in the cutting process is analyzed comprehensively and the formation mechanism of graded polycrystalline copper is explained by combining the simulation results.

Background: Colorectal cancer (CRC) is a prevalent malignancy of the digestive tract. A new prognostic scoring model for colon adenocarcinoma (COAD) is developed in this study based on the genes involved in tumor cell-mediated killing of T cells (GSTTKs), accurately stratifying COAD patients, thus improving the current status of personalized treatment. Method: The GEO and TCGA databases served as the sources of the data for the COAD cohort. This study identified GSTTKs-related genes in COAD through single-factor Cox analysis. These genes were used to categorize COAD patients into several subtypes via unsupervised clustering analysis. The biological pathways and tumor microenvironments of different subgroups were compared. We performed intersection analysis between different subtypes to obtain intersection genes. Single-factor Cox regression analysis and Lasso-Cox analysis were conducted to establish clinical prognostic models. Two methods are used to assess the accuracy of model predictions: ROC and Kaplan-Meier analysis. Next, the prediction model was further validated in the validation cohort. Differential immune cell infiltration between various risk categories was identified via single sample gene set enrichment analysis (ssGSEA). The COAD model's gene expression was validated via single-cell data analysis and experiments. Result: We established two distinct GSTTKs-related subtypes. Biological processes and immune cell tumor invasion differed significantly between various subtypes. Clinical prognostic models were created using five GSTTKs-related genes. The model's risk score independently served as a prognostic factor. COAD patients were classified as low- or high-risk depending on their risk scores. Patients in the low-risk category recorded a greater chance of surviving. The outcomes from the validation cohort match those from the training set. Risk scores and several tumor-infiltrating immune cells were strongly correlated, according to ssGSEA. Single-cell data illustrated that the model's genes were linked to several immune cells. The experimental results demonstrated a significant increase in the expression of HOXC6 in colon cancer tissue. Conclusion: Our research findings established a new gene signature for COAD. This gene signature helps to accurately stratify the risk of COAD patients and improve the current status of individualized care.

There are studies on titanium gypsum (TG) as a cement retarder, cementing material, or the production of lightweight wall materials and roadbed materials, but the application of TG is still limited, the utilization of TG is in the stage of exploration. This work studied the possibility of recycling TG as raw materials for the preparation of cement-based (Sulphate Aluminate Cement and Ordinary Portland Cement) self-leveling mortars. The effects of TG on mechanical strength, fluidity, shrinkage, and wear resistance were carried out. With the help of XRD, TG-DTG, and SEM, the microstructural characteristics were investigated to determine the mechanism of TG. It was concluded that the 1 d compressive and flexural strength reached 9.6 MPa and 3.5 MPa, respectively, and the 28 d compressive and flexural strength reached 4.3 MPa and 17.9 MPa, respectively, when the mass ratio of Sulphate Aluminate Cement (SAC) and Ordinary Portland Cement (OPC) was 7:3, the TG content was 45 %. TG could significantly improve the shrinkage of the mortars to 0.10 %, which was far better than the standard requirements of 0.15 %, but reduce the wear resistance to some extent. The primary component of calcium sulfate dihydrate (CaSO4·2H2O) in TG can further react with the aluminum phase in cement to grow more ettringite, which can make the microstructure denser, thereby improving the strength and the deformation of the cement-based self-leveling mortars.