Silicon carbide particle reinforced aluminum matrix (SiCp/Al) composites are increasingly used in high−end industries because of their superior comprehensive material properties. However, their advanced properties also create severe challenges for traditional processing technologies. A new hybrid machining method named photocatalytic−assisted jet electrochemical machining (PAJECM) is proposed to improve the machining capability by synchronously removing the metal aluminum matrix and the SiC particles. Comparative experiments were carried out on whether photocatalysis was added. The results show that after photocatalytic−assisted jet electrochemical machining, the height of SiC particles’ extrusion on the surface is significantly reduced. Compared with jet electrochemical machining (JECM) without photocatalysis at the same processing voltage, the surface roughness value is reduced, and the processing quality is improved. In PAJECM, the aluminum matrix is removed by electrochemical anodic dissolution, while the SiC particles generate a SiO2 reaction layer through photocatalysis, and the TiO2 abrasive flow’s mechanical action repeatedly removes the reaction layer. The electrochemical polarization curves and energy diffraction spectroscopy elemental analysis confirmed the material removal mechanism of PAJECM. Based on analyzing the phenomenon of material removal in detail, a qualitative model of the PAJECM material removal mechanism is established. This study provides valuable insights into the material removal mechanism in photocatalytic and jet electrochemical machining composite processes.
Objectives
This study aimed to determine the function of Cx43 in the endothelial-to-mesenchymal transition (EndMT) process of endothelial cells (ECs) and to explore the potential signaling pathways underlying these functions.
Methods
Endothelial cells (ECs) were extracted from rat aorta. ECs was transfected with Cx43 cDNA, Cx43 siRNA and then exposed to 5 or 12 dyne/cm2. Immunofluorescence staining was used to detect the expression of SM22α in ECs, Cx43 and acetylated-α tubulin in ECs. Western Blotting was used to detected the protein expression of α-SMA, CD31, Cx43, H1-caponin, Ift88 and p-smad3 in ECs.
Results
The expression of αSMA, SM22α and Cx43 was significantly increased and CD31 was markedly decreased in ECs treated with laminar shear stress at 5 dyn/cm2. The Cx43 cDNA transfection could induce the expression of SM22α or H1-caponin, and attenuate CD31 expression in the ECs. Also, Cx43 overexpression harms cilia formation in ECs exposed to 5dyn/cm2, accompanied with the regulated Ift88 and smad signaling.
Conclusions
This study found that laminar shear stress at 5 dyn/cm2 would increase the expression of Cx43, and interfere with primary cilia formation by inhibiting the expression of Ift88 in ECs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.