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Small cutting thicknesses are commonly employed to minimize surface damage during the CFRP finishing process. However, reducing cutting thickness is not always beneficial to surface quality and the cutting process, particularly in cases involving tool wear. In this paper, the influence of cutting thicknesses on CFRP material removal behavior is studied, considering different stages of tool wear, through finite element simulations and orthogonal cutting experiments. The results show that tool wear exerts a more pronounced impact on the chip formation mechanism at smaller cutting thicknesses. When the fiber cutting angle θ = 0°, machining quality is minimally influenced by the cutting thickness but is primarily affected by tool wear. When θ = 45°/90°, it becomes challenging to form cutting chips when using worn tools at small cutting thicknesses (≤10 μm), but appropriately increasing the cutting thickness is conducive to fiber removal and enhancing machining quality. When θ = 135°, the chip formation mechanism remains relatively unchanged with tool wear, but the increase in cutting thickness results in a substantial rise in subsurface damage. This research illuminates the complex relationship between cutting thickness, tool wear and machining quality of CFRP, offering valuable insights for the CFRP cutting process.

Objective: Ephedrine hydrochloride (EH) is a major component from Ephedra sinica STAPF, which is used as a traditional Chinese herbal medicine. This study was designed to investigate the effect of EH on water metabolism and further explore the relevant signaling pathway of body fluid regulation in “lung governing regulation of water passage” using a rabbit model of mechanical ventilation. The molecular mechanism of the EH effect in the kidney was also investigated. Methods: Rabbits were randomly divided into a control group, model group, EH group, and dexmedetomidine hydrochloride (DH) group. Urine volume was measured by the intubation method and pathologic changes in lung and renal tissue were measured by hematoxylin and eosin staining. Nitric oxide (NO) production in lung, serum, and kidney were analyzed using chemical methods. An ELISA was used to analyze angiotensin II (Ang II), antidiuretic hormone (ADH), prostaglandin E2 (PGE2), atrial natriuretic peptide (ANP), and endothelin-1 (ET-1) levels in the lung, serum, and kidney. Aquaporin-1 (AQP1) and aquaporin-2 (AQP2) mRNA and protein expression in the kidney was determined using qRT-PCR and immunohistochemistry. Results: EH significantly inhibited the decrease in the total urine volume in the third and fourth stages, and displayed significant regulatory effects on NO, Ang II, ADH, PGE2, ANP, and ET-1 in serum, lung, and renal tissues compared with the model group. In the kidney, AQP1 and AQP2 mRNA and protein expression in the EH group were remarkably down-regulated compared with the model group. Conclusion: EH exerted a regulatory effect on water metabolism by diffusing the lung and increased urine volume in the rabbit model, which was consistent with the decrease in kidney AQP1 and AQP2 expression levels that led to an increase in urine volume. EH could assist with DH to exert a protective effect on the clinical application of mechanical ventilation. Keywords: Mechanical ventilation, Ephedrine hydrochloride, Dexmedetomidine hydrochloride, Humoral regulation

Objective: To explore biological mechanisms underlying the traditional Chinese medicine theory of “lung governing the regulation of water passage” by observing effects of mechanical ventilation on urine volume and related bioactive substances. Methods: A total of 16 male rabbits were randomly divided into control and lung expansion model groups (n = 8 per group), which were examined during the following four respiratory intervention stages (10 minutes each): (1) free breathing without any respiratory intervention; (2) lung expansion induced by mechanical ventilator; (3) free breathing without ventilator intervention; (4) cutting of bilateral sympathetic, vagus, and depressor nerves with mechanical ventilation. Data for breathing rate, blood pressure, and urine drops were recorded with a Medlab data acquisition system. Levels of nitric oxide (NO), antidiuretic hormone (ADH), endothelin 1 (ET-1), angiotensin II (AngII), prostaglandin E2 (PGE2), and atrial natriuretic peptide (ANP) were detected in lung tissue, kidney tissue, and serum by enzyme-linked immunosorbent assay. Protein expression of aquaporins 1 and 2 (AQP1 and AQP2) was detected in kidney tissue by immunohistochemistry, while Aqp1 mRNA and Aqp2 mRNA levels in kidney tissue were detected by real-time quantitative polymerase chain reaction. Histopathological changes in lung and kidney tissues were examined by hematoxylin and eosin staining. Results: Compared with the control group, number of urine drops during the second and fourth stages is significantly decreased in the model group (P