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High-pressure pure waterjet (WJ) technology is widely used in the hole drilling process for carbon fiber–reinforced polymers (CFRP) laminates because of its high processing efficiency and zero heat affected zones. However, the phenomena of the delamination zone and poor roundness pose significant challenges to the hole processing of CFRP laminates. In this study, the numerical and experimental investigation of a high-pressure pure WJ CFRP laminate drilling process are conducted, to improve the quality of the pure WJ drilling process. A comprehensive coupled fluid–solid numerical model based on the smoothed particle hydrodynamics method is developed to simulate the pure WJ drilling process of CFRP laminates and determine mechanism of the material removal. Thereafter, extensive pure WJ drilling experiments are conducted on two stacking sequence CFRP laminates to obtain a hole with remarkable roundness. The simulation results illustrate that during the WJ drilling of CFRP laminates, the material removal process and damage zones of each inter-laminate interface are mainly extended along the fiber direction (the direction of longitudinal Young's modulus). Water-wedging action is observed to play an important role in the damage of inter-laminate interface and propagation of peel-up and push-down delamination. Furthermore, the experimental results show that an increase in the WJ pressure contributes to the reduced hole taper and surface roughness of sidewalls. Holes with diameters below 2 mm are successfully drilled, and a roundness error of 0.05 mm is obtained for the [0/45/–45/90]2s CFRP laminate, which is 1/6 of that of the [0]16 laminate. [ABSTRACT FROM AUTHOR]

Intensified sanitation practices amid the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak might result in the increased release of chloramine disinfectants into surface water, significantly promoting the formation of nitrosamine disinfection by-products (DBPs) in drinking water. Unfortunately, these nitrosamine DBPs exhibit significant genotoxic, carcinogenic, and mutagenic properties, whereas chlorinating disinfectants remain in global practice. The current review provides valuable insights into the occurrence, identification, contamination status, exposure limits, and toxicity of the new unregulated disinfection by-products (nitrosamine DBPs) in drinking water. As a result, concentrations of nitrosamine DBPs far exceed allowable limits in drinking water, and prolonged exposure has the potential to cause metabolic disorders, a critical step in tumor initiation and progression. Importantly, based on recent research, we have concluded the role of nitrosamines DBPs in different metabolic pathways. Remarkably, nitrosamine DBPs can induce chronic inflammation and initiate tumors by activating sphingolipid and polyunsaturated fatty acid metabolism. Regarding amino acid and nucleotide metabolism, nitrosamine DBPs can inhibit tryptophan metabolism and de novo nucleotide synthesis. Moreover, inhibition of de novo nucleotide synthesis fails to repair DNA damage induced by nitrosamines. Additionally, the accumulation of lactate induced by nitrosamine DBPs may act as a pivotal signaling molecule in communication within the tumor microenvironment. However, with the advancement of tumor metabolomics, understanding the role of nitrosamine DBPs in causing cancer by inducing metabolic abnormalities significantly lags behind, and specific mechanisms of toxic effects are not clearly defined. Urgently, further studies exploring this promising area are needed. [ABSTRACT FROM AUTHOR]

The pure waterjet (WJ) drilling process of carbon-fiber-reinforced polymer (CFRP) laminates causes damage, such as tears and delamination, leading to poor-quality hole-wall. Ultrasonic-vibration-assisted technology can improve the quality of hole walls and repair such damage, particularly the delamination of CFRP laminates. In this study, we conducted a numerical and experimental investigation of a high-pressure pure WJ drilling process of CFRP laminates performed using ultrasonic vibration to improve the delamination phenomena of the pure WJ drilling process. An explicit dynamic model using the smoothed particle hydrodynamics method was employed to simulate the ultrasonic-vibration-assisted WJ drilling of CFRP laminates and ascertain the optimal drilling performance. Thereafter, WJ drilling experiments were conducted to verify the numerical simulation. The results illustrate that the employment of ultrasonic vibration significantly increased the material removal rate by approximately 20%. Moreover, the water-wedging action that induces the propagation of delamination was weakened with an increase in the amplitude of the ultrasonic vibration. The hole-wall quality was optimal with the following drilling parameters: amplitude, 10 μm; frequency, 20 kHz; and WJ velocity, 900 m/s. The delamination zone length was only 0.19 mm and was reduced by 85.6% compared with the values obtained using non-assisted WJ drilling. [ABSTRACT FROM AUTHOR]

Abrasive waterjet (AWJ) cutting technology has notable advantages such as high cutting efficiency and cost-effectiveness, particularly for machining difficult-to-process metal matrix composites such as SiCp/Al. However, the uncontrollable kerf shape, cutting depth, and surface quality render AWJ grooving on SiCp/Al substrate challenging. In this study, a novel method for grooving on SiCp/Al substrate using AWJ, with the aim of enhancing the quality of AWJ machining processes, is proposed. First, a predictive model based on the improved model of erosion by the impact of solid particle is established for the geometry of groove kerf profiles. Second, a comprehensive analysis is performed to investigate the influence of process parameters on the quality of grooves using the waterjet cutting mechanism, thereby identifying the optimal process parameters for achieving superior results. Finally, the proposed predictive model of the kerf depth is used to predict the groove depth in multi-pass waterjet cutting. The results reveal that the combination of machining parameters comprising 100 MPa, 500 mm/min, and two waterjet passes achieves a desirable kerf shape, lowest roughness value of 5.11 μm, and flattest bottom profile. Additionally, these parameters achieve a high material removal rate of up to 1326.17 mm3/min. The predicted depth results agree well with the five multi-pass experimental results, and the average difference between the predicted model and the experimental results is 5.24%. This study can provide crucial guidelines for the AWJ grooving process of SiCp/Al substrates. [ABSTRACT FROM AUTHOR]

N-Nitrosamine disinfection by-products (NAs-DBPs) have been well proven for its role in esophageal carcinogenesis. However, the role of intratumoral microorganisms in esophageal squamous cell carcinoma (ESCC) has not yet been well explored in the context of exposure to NAs-DBPs. Here, the multi-omics integration reveals F. periodonticum ( Fp ) as "facilitators" is highly enriched in cancer tissues and promotes the epithelial mesenchymal transition (EMT)-like subtype formation of ESCC. We demonstrate that Fp potently drives de novo synthesis of fatty acids, migration, invasion and EMT phenotype through its unique FadAL adhesin. However, N-nitrosomethylbenzylamine upregulates the transcription level of FadAL. Mechanistically, co-immunoprecipitation coupled to mass spectrometry shows that FadAL interacts with FLOT1. Furthermore, FLOT1 activates PI3K-AKT/FASN signaling pathway, leading to triglyceride and palmitic acid (PA) accumulation. Innovatively, the results from the acyl-biotin exchange demonstrate that FadAL-mediated PA accumulation enhances Wnt3A palmitoylation on a conserved cysteine residue, Cys-77, and promotes Wnt3A membrane localization and the translocation of β-catenin into the nucleus, further activating Wnt3A/β-catenin axis and inducing EMT phenotype. We therefore propose a "microbiota-cancer cell subpopulation" interaction model in the highly heterogeneous tumor microenvironment. This study unveils a mechanism by which Fp can drive ESCC and identifies FadAL as a potential diagnostic and therapeutic target for ESCC.

The pure waterjet (WJ) drilling process of carbon-fiber-reinforced polymer (CFRP) laminates causes damage, such as tears and delamination, leading to poor-quality hole-wall. Ultrasonic-vibration-assisted technology can improve the quality of hole walls and repair such damage, particularly the delamination of CFRP laminates. In this study, we conducted a numerical and experimental investigation of a high-pressure pure WJ drilling process of CFRP laminates performed using ultrasonic vibration to improve the delamination phenomena of the pure WJ drilling process. An explicit dynamic model using the smoothed particle hydrodynamics method was employed to simulate the ultrasonic-vibration-assisted WJ drilling of CFRP laminates and ascertain the optimal drilling performance. Thereafter, WJ drilling experiments were conducted to verify the numerical simulation. The results illustrate that the employment of ultrasonic vibration significantly increased the material removal rate by approximately 20%. Moreover, the water-wedging action that induces the propagation of delamination was weakened with an increase in the amplitude of the ultrasonic vibration. The hole-wall quality was optimal with the following drilling parameters: amplitude, 10 μm; frequency, 20 kHz; and WJ velocity, 900 m/s. The delamination zone length was only 0.19 mm and was reduced by 85.6% compared with the values obtained using non-assisted WJ drilling.