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In this study, to address the low efficiency for conventional ultrasonic-assisted drilling (UAD) of carbon fiber-reinforced plastic and titanium alloy (CFRP/Ti) stacks, feasibility experiments of non-separation UAD, in which continuous cutting between the tool and the workpiece occurs at a high feed rate, are carried out. The experimental results indicate that, compared to conventional separation UAD, the non-separation UAD effectively reduces the cutting forces by 24.2% and 1.9% for CFRP stage and 22.1% and 2.6% for the Ti stage at the feed rates of 50 and 70 µm/r, respectively. Furthermore, the non-separation UAD significantly improves hole quality, including higher hole diameter accuracy, lower hole surface roughness, and less hole damage. In addition, the non-separation UAD can decrease adhesive tool wear. This study demonstrates that, compared to conventional drilling (CD), the non-separation UAD can effectively improve drilling quality and tool life while maintaining high efficiency.

At present, the aviation industry puts forward higher requirements for high-performance milling technology of carbon fiber reinforced plastic (CFRP). This paper proposed a sharpening milling CFRP strategy by combining of ultrasonic vibration and optimized tool structure of fluted burr tools. The sharpening cutting mechanisms of the ultrasonic vibration and tool structure were analyzed theoretically first. Next, the milling performance of optimized fluted burr tool was verified compared with conventional helical end mill and the results showed the optimized tool structure had positive effects on damage suppression and surface roughness. On this basis, Ultrasonic vibration-assisted milling (UVM) with the optimized fluted burr tool was applied to further improve the machined surface quality of T800 CFRP. The verification experimental results showed that, compared to conventional milling, both the cutting force and cutting temperature were significantly reduced in UVM, with a maximum decrement of 39.7% and 15.7% respectively. Besides, the surface defects were significantly suppressed and the surface roughness was reduced by 11.4%–37.6% in UVM. The results of this paper suggested that the combination of UVM and optimized fluted burr tool was an efficient and low damages milling strategy for CFRP.

ABSTRACTDepletion of T regulatory cells (Tregs) in the tumor microenvironment is a promising cancer immunotherapy strategy. Current approaches for depleting Tregs are limited by lack of specificity and concurrent depletion of anti-tumor effector T cells. The transcription factor forkhead box p3 (Foxp3) plays a central role in the development and function of Tregs and is an ideal target in Tregs, but Foxp3 is an intracellular, undruggable protein to date. We have generated a T cell receptor mimic antibody, “Foxp3-#32,” recognizing a Foxp3-derived epitope in the context of HLA-A*02:01. The mAb Foxp3-#32 selectively recognizes CD4 + CD25 + CD127lowand Foxp3 + Tregs also expressing HLA-A*02:01 and depletes these cells via antibody-mediated cellular cytotoxicity. Foxp3-#32 mAb depleted Tregs in xenografts of PBMCs from a healthy donor and ascites fluid from a cancer patient. A TCRm mAb targeting intracellular Foxp3 epitope represents an approach to deplete Tregs.