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Aluminum has a certain chemical activity， and easily forms a dense oxide film after the reaction with oxygen which can effectively prevent the sample from further deep oxidation， playing good oxygen-blocking protection， commonly used as cathodic protection material.By introducing aluminum into iron-based alloy coatings， the corrosion resistance of these coatings can be enhanced.In this research， different particle sizes of aluminum powder were incorporated into plasma cladded iron-based coatings to investigate the influence of particle size on the microstructure， morphology and corrosion resistance of the coatings.The underlying mechanisms affecting the corrosion resistance of the clad layers were also analyzed.Results showed that the iron-based clad layer had good metallurgical bonding with the substrate and the clad layer did not produce obvious cracks and pores.As the particle size of the aluminum powder (100～200 mesh， 200～300 mesh， 300～400 mesh， 400～500 mesh) decreased， the size of the black AlN phase within the overlay also reduced， resulting in a more uniform distribution.All overlays displayed pronounced passivation behavior in a 3.5%NaCl solution.The self-corrosion potentials were－0.665，－0.706，－0.752 and－0.822 V， which were higher than that of the substrate (－0.883 V)， and the self-corrosion current densities were 2.454×10－6， 6.313×10－6， 7.979×10－6 and 9.710×10－6 A/cm2， which were lower than that of the substrate 3.323×10－5 A/cm2.As the particle size of aluminum powder increased， the corrosion resistance of the clad layer gradually increased， and the best corrosion resistance of the clad layer was obtained when the particle size of aluminum powder was 100～200 mesh， and the corrosion resistance of the clad layer was better than the base material.

A biphasic hyperbaric injector based on BLDC is designed for alternate and mixed injection of contrast medium and normal saline in the process of contrast medium injection in hospital. The driver hardware and algorithm are optimized especially for high-pressure and high-speed injection requirements. The interface APP is designed with parameter-input and real-time pressure-plotting of injector's ports as two main functions. The whole device can realize the preset function and has high stability after testing.

Objective: To study the changes of CD4(+);CD25(+);CD127(low); regulatory T cells (Tregs) and transforming growth factor beta 1 (TGF-β1) mRNA in peripheral blood mononuclear cells (PBMCs) in drug addicts during natural drug withdrawal, and explore the effects of addictive drugs on their Tregs., Methods: Peripheral blood was collected from 40 drug addicts with 6-month natural withdrawal, 40 cases with 18-month natural withdrawal and 30 healthy controls. Then the Tregs were counted by flow cytometry and TGF-β1 mRNA expression in PBMCs was detected by RT-PCR., Results: Compared with the controls, Tregs and TGF-β1 mRNA expression in PBMCs increased significantly in the group with one 18-month natural withdrawal, but no significant difference was found in the group with 6-month natural withdrawal., Conclusion: Addictive drugs have a long-term effect on the Tregs in drug addicts, and the abnormal Tregs may result in the immune dysfunction in drug addicts.

Objective: To explore if vasculogenic mimicry (VM) exists in bi-directional differentiation malignant tumor., Methods: New sections were made from 158 paraffin sections of bi-directional malignant tumors, including malignant melanoma (n = 60), synoviosarcoma (n = 39), rhabdomyosarcoma (n = 29), malignant mesothelioma (n = 26), and epithelioid sarcoma (n = 4). The representative points in the paraffin sections were labeled and two tissue microarrays were made, one including 60 cases of malignant melanoma, and the other including the other tumors. Immunohistochemical staining of platelet-endothelial cell adhesion molecule (CD31 antigen) and periodic acid Schiff (PAS) staining were conducted. Microscopy was made and the areas of vessel-like channels consisted of CD31 antigen-positive tumor cells and of PAS positive material were calculated., Results: PAS positive material or CD31 positive material were observed in these bi-directional tumor cells. In the tumors vessel-like channels could be found, made of PAS positive material lined with CD31 negative tumor cells and red blood cells inside the channel, or made of tumor cells with CD31 positive material. The area of the former vessel-like channels was significantly smaller than that of the latter (P < 0.01). VM was found in 16 of the 39 cases of the highly malignant synoviosarcoma and acinar type rhabdomyosarcoma, a ratio higher than that among the cases of synoviosarcoma and acinar type rhabdomyosarcoma with lower malignancy (5/29) (P < 0.05)., Conclusion: VM exists in bi-directional differentiation malignant tumors.