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In the present research, the impacts of Ce additions at various concentrations (0, 1.0, 3.4, and 4.0 wt.%) on the evolution of the microstructure, mechanical properties, and thermal conductivity of as-cast and as-extruded Mg-3Sn alloys were investigated. The findings demonstrate that adding Ce caused the creation of a new ternary MgSnCe phase in the magnesium matrix. Some new Mg17Ce2 phases are generated in the microstructure when Ce levels reach 4%. The thermal conductivity of the Mg-3Sn alloy is significantly improved due to Ce addition, and the Mg-3Sn-3.4Ce alloy exhibits the highest thermal conductivity, up to 133.8 W/(m·K) at 298 K. After extrusion, both the thermal conductivity and mechanical properties are further improved. The thermal conductivity perpendicular to the extrusion direction of Mg-3Sn-3.4Ce alloy could achieve 136.28 W/(m·K), and the tensile and yield strengths reach 264.3 MPa and 227.2 MPa, with an elongation of 7.9%. Adding Ce decreases the dissolved Sn atoms and breaks the eutectic α-Mg and Mg2Sn network organization, leading to a considerable increase in the thermal conductivity of as-cast Mg-3Sn alloys. Weakening the deformed grain texture contributed to the further enhancement of the thermal conductivity after extrusion. [ABSTRACT FROM AUTHOR]

Selective laser sintering technology is not limited by the shape of the parts, and can form parts with complex structures. Selective laser sintering technology is widely used in rapid prototyping manufacturing and new product design and development. It is particularly important to explore the dimensional accuracy of its forming. Aiming at the problem of low dimensional accuracy and shape accuracy of thin-walled shell parts, this paper proposes a method of preprocessing and precompensation based on part features to improve printing accuracy. Taking polystyrene as raw material, under the combination of simulation and experiment, in order to compensate the deformation, the method of adding support and offset margin is used to correct the feature size, which is easy to warp and deform, and the laser parameters are adjusted to improve the heat accumulation in the printing process. By verifying the printing results, the results show that under the same process conditions, the change of the geometric features of the part directly affects the dimensional accuracy of the part. After adding support settings and predeformation compensation to the part features, the printed parts are compared with the 3D model with good detection results, and the actual error can basically be controlled within 0.3 mm. [ABSTRACT FROM AUTHOR]

Objective: To investigate the expression and its significance of tumor necrosis factor-alpha (TNF-alpha) and caspase-3 protein in monocytes adjacent to the invaded Echinococcus multilocularis in liver., Methods: 40 female Kunming mice were randomly divided into experimental group (n=20) and sham operation (control) group (n=20). Mice in experimental group were infected with 20% E. multilocularis suspension (0.1 ml per mouse) through abdominal opening injection in liver and the mice in control group were injected with equal physiological saline. The mice were sacrificed at 6 months post-infection for observing the growth and metastasis of E. multilocularis. Pathological changes were observed by HE staining. The expression of TNF-alpha and caspase-3 protein in hydatid cyst and metastasis tissue were detected by immunohistochemistry staining and the apoptosis of the monocytes was measured by TUNEL., Results: After 6 months post-infection, E. multilocularis were spread over the liver of the mice in experimental group. Metastasis rate of lymph nodes was 45.0% (9/20). Infiltration of monocytes was observed around E. multilocularis in liver and lymph nodes with metastasis by HE staining. Immunohistochemistry showed that the positive expression rate of TNF-alpha and caspase-3 protein in monocytes was 100% and 100%, and 95% and 100% respectively around the cyst in experimental group, while the expression rate was only 5% and 0 respectively in the liver of the control mice (P<0.01). The monocytes showed significant apoptosis by TUNEL in experimental group with a positive expression rate of 100%, with a significant difference between experiment group and the control (P<0.01)., Conclusion: In the process of alveolar Echinococcus infection, the high expression of TNF-alpha protein might be associated with the apoptosis of monocytes, which may inhibit the host immunological function.