Application of Novel Down-sampling Method in Retinal Vessel Segmentation / 中国医疗器械杂志

Accurate segmentation of retinal blood vessels is of great significance for diagnosing, preventing and detecting eye diseases. In recent years, the U-Net network and its various variants have reached advanced level in the field of medical image segmentation. Most of these networks choose to use simple max pooling to down-sample the intermediate feature layer of the image, which is easy to lose part of the information, so this study proposes a simple and effective new down-sampling method Pixel Fusion-pooling (PF-pooling), which can well fuse the adjacent pixel information of the image. The down-sampling method proposed in this study is a lightweight general module that can be effectively integrated into various network architectures based on convolutional operations. The experimental results on the DRIVE and STARE datasets show that the F1-score index of the U-Net model using PF-pooling on the STARE dataset improved by 1.98%. The accuracy rate is increased by 0.2%, and the sensitivity is increased by 3.88%. And the generalization of the proposed module is verified by replacing different algorithm models. The results show that PF-pooling has achieved performance improvement in both Dense-UNet and Res-UNet models, and has good universality.

Ubiquitin C-terminal hydrolase 37 promotes the proliferation of colon cancer cells by de-ubiquitinating MIF / 实用医学杂志

Objective To explore the expression and cilinical significance of UCH37 in colon cancer, and detect the effects and underlying mechanism of UCH37 on cell proliferation and cell apoptosis of colon cancer cell lines. Methods Expressions of UCH37 were analyzed by immunohistochemistry in colon cancer patients. Spearman′s rank test was conducted to analyze the clinical relevance of UCH37 in colon cancer. QPCR was conducted to detect the expression of UPS39 in colon cancer cell lines and NCM460 cells.CCK-8,flow cytometry, co-immunoprecipitation were conducted to detect the effects of UCH37 on cell proliferation,cell apoptosis. And ubiquitinated level of MIF. Results Compare to adjacent tissues,immunohistochemistry and chi square analysis revealed that the positive rate of UCH37 was upregulated in colon cancer tissues.Spearman rank correlation showed that positive UCH37 expression was significantly associated with TNM stage and cell differentiation of colon cancer patients. CCK-8 results showed cell proliferation in colon cancer cells transfected with UCH37 NC was promoted and cell apoptosis in colon cancer cells transfected with UCH37 NC was inhibited compared with cells transfected UCH37 siRNAs;furthermore,compared to cells transfected lentiviral vector carrying pLenti6.3.cell proliferation in colon cancer cells transfected with lentiviral vector carrying UCH37 was promoted and cell apoptosis in colon can-cer cells transfected with lentiviral vector carrying UCH37 was inhibited.Co-IP showed MIF could be deubiquitinat-ed by UCH37 in colon cancer cells. Conclusion UCH37 expression is upregulated in colon cancer,and UCH37 could promote cell proliferation of colon cancer cells by deubiquitinating MIF.