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ABSTRACT The TC4 titanium (Ti) alloy has been widely utilized in various industries such as aerospace and shipbuilding, owing to its numerous advantages. Its exceptional properties have made it a material of choice for applications requiring high performance and reliability. The total weld thickness was 140 mm, and microstructures and high‐cycle fatigue properties were investigated at three different layers within the 140‐mm section. Experimental results show that the overlap area at two weld roots has the highest microhardness and largest nonuniformity of the overall joints, so the area is found to have the poorest high‐cycle fatigue properties. The microstructures in every layer of the weld metal of the joints were analyzed to determine the causes of the poor fatigue properties in the overlapping area at the weld roots. Significant amounts of α′ acicular microstructure are present in the weld metal of joints, while the overlap area at weld roots contains more α′ acicular microstructure with a finer size. Compared with other layers, the weld metal and base metal in Layer 2 (overlap area) have the largest microhardness gradient, where the stress concentration is more serious in the fatigue experimental process. Heat dissipation conditions was a critical factor for the inhomogeneity of microstructure and mechanical properties along the thickness direction of 140‐mm double‐sided electron beam welding joint. Fatigue damage (micropore) is formed at β phases in priority, and fatigue cracks propagate via series connection of micropores, indicative of transgranular ductile cracks. [ABSTRACT FROM AUTHOR]

Reducing cadmium (Cd) accumulation in wheat is an effective way to decrease the potential threats of Cd to human health. The application of lanthanum (La) in agricultural fields is eliciting extensive attention due to its beneficial effects on improving yields and inhibiting Cd accumulation in edible parts of crops. However, the potential mechanism of La-restricted Cd accumulation in crop grains is not entirely understood. Here, we investigated the effects of La and Cd accumulation in wheat grains by implementing application at the shooting and heading stages. Some associated mechanisms were explored. Results showed that La application at the shooting and heading stages considerably promoted the thousand-grain weight. La application at the shooting and heading stages increased Cd accumulation in the first node beneath the panicle (N1) but reduced Cd levels in the other tissues. La application at the heading stage exerted greater effects on Cd storage in N1 while reducing Cd concentrations in the other tissues compared with La application at the shooting stage. La addition substantially decreased the translocation of Cd from the lower nodes to the upper internodes, but increased Cd translocation from the lower internodes to the upper nodes. The expression of TaZIP7 in N1 was downregulated by La treatment. These results suggest that the effective reduction in Cd in wheat grains by La application at the heading stage is probably a consequence of the successful promotion of Cd storage in nodes by downregulating the expression of TaZIP7 during the grain-filling stage, thereby hindering the redirection Cd from nodes to grains. [ABSTRACT FROM AUTHOR]

AIM: To investigate the effects and underlying mechanism of Toona sinensis bark extract (TAE) on the colon mucosal barrier and gut microbiota in mice with ulcerative colitis (UC) induced by dextran sulfate sodium (DSS). METHODS: Sixty C57BL/6J mice were randomly assigned to control, model, and mesalazine (0.2 g/kg) groups, as well as TAE groups (low, medium, and high-doses equal to crude drug concentrations of 2. 3, 4. 6 and 9. 2 g/ kg respectively) . The UC model was induced by drinking of 2. 5% DSS and mean while the drugs were administered for 10 days. The mice were then evaluated in terms of weight, disease activity index (DAI), colon length, spleen index, and pathological changes in the colon tissues. In addition, the level of apoptosis in colon tissues was assessed by terminal de-oxynucleotidyl transferase dUTP nick-end labeling (TUNEL) fluorescence staining, and the expression of related proteins was evaluated by Western blot, levels of inflammatory factors were determined by enzyme-linked immunosorbent assays (ELISA), and the activities of total superoxide dismutase (T-SOD) and catalase (CAT) and malondialdehyde (MDA) content were assessed by biochemical assays. Furthermore, the constitution and diversity of the gut microbiota were investigated by 16S rRNA gene sequencing. RESULTS: Compared with the control group, mice in the model group showed significantly reduced body weights (P<0. 01), and the colon length was shortened significantly (P<0. 05). Marked increases in the DAI and spleen index were observed (P<0. 01), along with severe damage to the colon mucosa (P<0. 01). Mechanistically, the level of intestinal epithelial cell apoptosis was significantly raised ( P<0. 01). The model group showed markedly reduced expression of occludin and claudin-1 (P<0. 01), the level of IL-10, and activities of T-SOD and CAT in the colon tissues (P<0. 01). While the levels of IL-6, IL-1β, TNF-α, and the MDA content were increased significantly (P<0. 05). The abundance and diversity of the gut microbiota were decreased in the model group (P<0. 05). Compared with the model group, all these indicators were ameliorated by the administration of TAE (P<0. 05). The abundance of pathogenic bacteria, including Proteobacteria and Escherichia-Shigella, was decreased remarkably (P<0. 05), while that of probiotics, including Bacteroidota and Muribaculaceae, were increased significantly (P<0. 05). The abundance and diversity of the gut microbiota were increased. CONCLUSION: Taken together, Toona sinensis bark alcohol extract can alleviate damage to the intestinal mucosa by suppressing the apoptosis of intestinal epithelial cell, reducing the inflammatory response, and mitigating oxidative stress. Treatment with TAE could also maintain the homeostasis of the gut microbiota by regulating the abundance, ultimately meliorate the function of intestinal mucosal barrier. [ABSTRACT FROM AUTHOR]