Uncontrolled growth, distant metastasis and chemoresistance are critical characteristics of pancreatic ductal adenocarcinoma (PDAC), and they result in high mortality; however, the mechanisms triggering these effects have not been fully investigated. In this study, we analysed a dataset in the Cancer Genome Atlas (TCGA) and identified PCDH1, a rarely studied transmembrane protein, as a novel prognostic marker in PDAC patients. We demonstrated that PCDH1 expression was upregulated in PDAC tissues, and its expression levels were associated with the depth of tumour invasion and lymph node metastasis. Patients with high PCDH1 levels showed poor overall survival (OS). We also investigated the biological significance of PCDH1 in PDAC cell growth, metastasis, and side population (SP) phenotype acquisition and explored the internal molecular mechanisms of PCDH1 action. Our results demonstrated that PCDH1 enhanced p65 nuclear localization by interacting with KPNB1, a well-characterized nuclear transporter, thereby activating the NF-κB signalling pathway and increasing its functional effects during PDAC progression. Hence, our results indicate that PCDH1 can be used as a negative prognostic marker and may be a potential therapeutic target for PDAC patients.

Drilling is frequently used in machining of carbon fiber reinforced materials. Twist drill is mostly used in drilling composite materials and some other drills with special drill bits are also needed. Drilling induced delamination is considered one of the most serious problems during machining while drilling force plays a decisive role in delamination. This paper presents the analysis of critical thrust force with special drill bit theoretically. The method of simulation to study the critical thrust force is also introduced. In addition, effect of cutting parameters on delamination by comparing experimental results and mathematical model of twist drill is studied.

Drilling procedure is widely used in orthopedic surgery to insert the steel nail to stabilize the bone. However, successful execution of bone drilling requires a high level of dexterity and experience, because the drilling resistance is large and sometimes vibrates violently to even break the slender drill. This paper introduces the study of drill force in different cutting parameters and different bone density. The density of cortical bone is higher than that of cancellous bone, so the drilling force decreases suddenly from the peak and then maintains a stable value. Drilling forces are more related with feed speeds and bone density. Drilling force increases as feed speed increases and bone density increases. Accurate drilling process can be obtained to provide effective surgery training and rehearsal.

Research has been done on machinability of two different kinds of free-cutting steels by using coated cutting tool at the condition of different cutting parameters. Orthogonal tests are adopted in order to compare the cutting performance of the two materials. The cutting force, surface roughness, chip morphology and tool wear are investigated, which reveal the influence of Pb and other composition on machinability. The experiment shows that 1215 has more or less better performance than 12L14. It is of great significance for the development of environmental friendly products.

Lots of hole machining in CFRP(carbon fiber reinforced plastics) are conducted in the astronautic fields, especially a large size hole machining. The purpose of this article is to investigate the optimal cutting parameters and allowance distribution in CFRP 18/32inch hole machining by thoroughly considering the cutting forces and burr length. All tests were run without coolant using different drills, expanding drills and reamers. The damage generated and the cutting forces produced in CFRP composites cutting were observed. Therefore, the optimal allowance distribution in CFRP large size hole machining was obtained, providing compound tools design with theoretical direction.