Search

Si3N4 ceramic has the advantages of high hardness, high strength, corrosion resistance, and high-temperature resistance and is widely used in aerospace and other fields. As a hard and brittle material, it is prone to problems such as difficult control of processing surface quality and low processing efficiency. In order to explore the influence of the interaction between abrasive grains on the surface processing quality and processing efficiency of Si3N4 ceramic in rotary ultrasonic grinding, the multigrain grinding simulation is carried out to explore the removal mechanism of Si3N4 ceramic material under multigrain coupling. The multi-abrasive scratch test was carried out to verify the simulation. The results show that as the number of abrasive particles increases, the machining forces in both simulations and experiments increase. Meanwhile, the average grinding force per individual abrasive particle decreases. The maximum stress generated by grinding increases first and then decreases as the number of abrasive particles increases. As the number of abrasive particles increases, the depth of surface cracks and the average depth of scratches caused by grinding first decrease and then increase. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction and necrotic apoptosis, pivotal in therapeutic strategies for multiple diseases, lack comprehensive understanding in the context of renal clear cell carcinoma (ccRCC). This study explores their potential as valuable tools for ccRCC prediction, prevention, and personalized medical care. Transcriptomic and clinical datasets were acquired from the Cancer Genome Atlas (TCGA) repository. Mitochondrial and necrosis-associated gene sets were sourced from MitoCarta3.0 and the KEGG Pathway databases, respectively. Six necrosis-related mitochondrial genes (nc-MTGs) with prognostic significance were analyzed and screened, and a prognostic model was constructed. The accuracy of the model was verified using external data (E-MTAB-1980). TISCH was used to explore nc-MTGs at the cellular level. Finally, the expression level of BH3 interacting domain death agonist (BID) in ccRCC cell line was detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and the effect of BID down-regulation on tumor cell migration was verified by transwell assays and wound-healing experiments. We established and validated a prognostic model for clear cell renal cell carcinoma (ccRCC) utilizing six necrosis-related mitochondrial genes (nc-MTGs), affirming its efficacy in evaluating tumor progression. RT-PCR results showed that BID expression was up-regulated in ccRCC tissues compared with controls and exhibited oncogenic effects. In vitro cell function experiments showed that BID may be an important factor affecting the migration of ccRCC. Our study is the first to elucidate the biological functions and prognostic significance of mitochondrial molecules related to necroptosis, providing a new way to evaluate mitochondrial therapeutics in patients with ccRCC. [ABSTRACT FROM AUTHOR]

The increasing demand for energy is leading to global depletion of fossil fuels and growing environmental pressures, which are issues that need to be addressed. Machine tools are basic energy-consuming equipment in manufacturing systems. However, existing theoretical models ignore tool wear as well as workpiece material properties. This makes it difficult to further improve the accuracy of the model. Therefore, this study begins with the point of view of energy dissipation in the metal material removal process. A milling power model for computer numerical control (CNC) machines, considering tool wear and workpiece material properties during machining, is established. At the same time, milling is taken as the research object. A multi-objective cutting parameter optimization model is established to ensure the surface quality of the workpiece. In addition, the cutting energy consumption is taken into account in the developed models. Based on the multi-objective manta ray foraging optimization algorithm (MOMRFO), the Pareto-optimal solution set under multiple cutting conditions is solved. Finally, the experimental results of optimized parameters are compared with empirical parameters. The average prediction accuracy of the proposed energy consumption prediction model is above 91%. The experiments show that machining quality improves by optimizing the cutting parameters, with SEC, MRR, and Ra increasing by more than 44%, 53%, and 38%, respectively. The goals of reducing energy consumption and increasing productivity are achieved. [ABSTRACT FROM AUTHOR]

Hot-pressed Si3N4 ceramic is a kind of high-performance ceramic material, which is widely used in national defense, aerospace, and other professional fields. Aiming at the problem of poor surface quality of Si3N4 ceramic material, the paper carried out a simulation study on the removal mechanism of Si3N4 ceramic by rotary ultrasonic grinding. The study provides a theoretical basis for improving the surface quality and processing efficiency of hot-pressed Si3N4 ceramics. Combined with dynamic simulation software to complete single abrasive and double abrasive rotary ultrasonic grinding simulation. Material removal and surface crack propagation in single and double abrasive grains rotary ultrasonic grinding of Si3N4 ceramic were analyzed by crack propagation theory. The grinding force of Si3N4 ceramics with different ultrasonic amplitude and grinding depth and the local stress change at the time of crack generation with different ultrasonic amplitude were compared and analyzed. Complete single abrasive and double abrasive rotary ultrasonic scratch test. The grinding force and surface crack generation obtained by rotary ultrasonic scratch test and rotary ultrasonic grinding simulation were analyzed. The maximum error of the simulation results of single-grain and double-grain rotary ultrasonic grinding is 12.8% and 14.7% respectively. The surface crack of the scratch test workpiece is consistent with the simulation results. [ABSTRACT FROM AUTHOR]

Nanosensors based on flexible polymers have emerged as powerful tools for next generation smart devices in the recent years. Here, we report a facile protocol to fabricate an immunosensor supported by a thermally resistant flexible polymer substrate (polyarylene ether nitrile, PEN). The immunosensor is a localized surface plasmon resonance (LSPR) optical sensor for in-vitro protein detection based on anti-body coated gold-silver bimetallic nanoparticles (Au-Ag NPs) immobilized on a PEN substrate. Plasmonic spectroscopy and morphological characterization show that the Au-Ag NPs essentially exhibit a more uniform size distribution and higher quality factors than those from single-component Au NPs. Furthermore, it should be noted that the robust PEN substrate in this nanosensor acts a flexible substrate to support Au-Ag NPs and immobilize the nanoparticles via quick thermal annealing at 290 °C. Thanks to these merits, a prostate-specific antigen (PSA) concentration as low as 1 ng/mL can be specifically discriminated via the prepared PEN/Au-Au NPs, which confirms that the protocol reported in this work can be readily adapted for the construction of various flexible immunosensors for different applications. [ABSTRACT FROM AUTHOR]

Objective: To investigate the significance of monitoring procalcitonin (PCT) when applying antibiotics to trichlorethylene (TCE)-induced dermatitis., Methods: One hundred and two patients who were hospitalized and recovered from TCE-induced dermatitis in our hospital from 2006 to 2013 were enrolled as subjects. Based on whether the PCT level was monitored or not, we divided patients into regular group and PCT group. For the regular group, we applied antibiotic treatment and determined the course of treatment based on clinical symptoms, laboratory test results, medical imaging results, and bacterial culture. For the PCT group, in addition to the above treatments, antibiotic treatment was applied when the PCT level was not lower than 0.25 ng/ml and stopped when the PCT level was lower than 0.25 ng/ml. The distribution of bacterial infection sites, type of bacteria, type of antibiotics, average period of hospitalization, and course of antibiotic treatment were compared between the two groups., Results: There were no significant differences in the distribution of bacterial infection sites, type of bacteria, type of antibiotics, and average period of hospitalization between the two groups (P > 0.05). The course of antibiotic treatment for the PCT group was significantly shorter than that for the regular group (25.37 ± 11.66 vs 20.58 ± 7.53 d, P < 0.05)., Conclusion: Under similar conditions of bacterial infection, antibiotic treatment of TCE-induced dermatitis based on the serum PCT level can significantly shorten the course of treatment and avoid the abuse of antibiotics.