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• CircPRDM5 was down-regulated in the serum of AMI patients and also in hypoxic-treated cells. • CircPRDM5 can make up for the lack of a long cTnT time window and help to identify recurrent infarction. • CircPRDM5 may be related to the degree of vascular stenosis in AMI patients, and can be used as a diagnostic biomarker for AMI. Circular RNA (CircRNA) is known to play an important role in cardiovascular diseases, but its use as a biomarker of acute myocardial infarction (AMI) has not been studied. This study explores the feasibility of circPRDM5 as a novel biomarker of AMI. CircPRDM5 was screened by bioinformatics, the correct circPRDM5 primers were tested by agarose gel electrophoresis (AGE) and Sanger sequencing, and the expression level of serum circPRDM5 was detected by Quantitative Reverse Transcription-Polymerase Chain Reaction. (qRT-PCR), and the diagnostic value of circPRDM5 was analyzed by the receiver operating characteristic (ROC) curve. The expression of circPRDM5 in serum of AMI patients was significantly decreased compared with that of healthy control group and angina group (P < 0.001). The area under ROC curve of serum circPRDM5 was 0.862 [95 % CI, 0.814–0.909]. The combined diagnosis of serum circPRDM5, cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB) could improve the sensitivity of diagnosing AMI. The expression level of serum circPRDM5 increased after percutaneous coronary intervention (PCI). CircPRDM5 can be used as a novel biomarker for AMI, and its combination with cTnT and CK-MB can improve diagnostic value. [ABSTRACT FROM AUTHOR]

Alumina (Al 2 O 3 ) ceramics were metallized by magnetron sputtering Ti/Mo bilayer films on the surface with a subsequent high temperature sintering and were brazed to Kovar alloy (Fe-Ni-Co) using Ag-Cu eutectic alloy. The Ti/Mo metallization film and the brazing seam microstructures were investigated and the correlation between the Al 2 O 3 /Kovar joining strength and the microstructures of the brazing seam was discussed. The results show that the joining strength is related to the thickness of the Ti/Mo adhension layer which depends on the holding time during brazing. The mutual diffusion of the elements at the interface firstly increases the thickness of the adhension layer as the holding time increases and the Mo film acts as a barrier layer to block the diffusion of Ti atoms into the seam. The optimal brazing joining strength of 72.6±5.0 MPa could be achieved at a brazing temperature of 810 °C for 14 min However, if the holding time is further prolonged, Mo atoms will diffuse into the (Ni, Cu) solid solution, resulting in the diffusion of Ti atoms and the adhension layer becoming indistinguishable. Therefore, the intermetallic Ni 3 Ti forms in the seam and the titanium oxide changes from TiO to Ti 2 O 3 or Ti 3 O 5 , which leads to the joint strength decreasing. [ABSTRACT FROM AUTHOR]