Simulation and optimization of giant radial tire vulcanization process

AbstractThe process of curing a pneumatic tire as one of the most important working procedures, directly identify the quality of tire, because the physical and mechanical properties of rubber in the state of overcure or undercure are significantly decreased. The finite element analysis (FEA) method was introduced to evaluate the tire's state of cure (SOC) in this paper, and the optimization of cure conditions of giant radial tire was also referred to ensure that tire constituents achieved the proper SOC and improved the quality of tire. Results indicated that when the cure time was cut down 35 minutes by optimization process, most part of tire compound is appropriate cured. So that the energy cost was remarkable cut down and the productivity was rising in evidence

MiR-143-5p inhibits proliferation, invasion, and epithelial to mesenchymal transition of colorectal cancer cells by downregulation of HMGA2

Purpose: To investigate the regulatory effect and molecular mechanism of miR-143-5p in colorectal cancer (CRC) progression. Methods: Expression of miR-143-5p in CRC cell lines SW620 and HCT116 was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Stable miR-143-5p overexpression was mediated by lentivirus. The effects of miR-143-5p on proliferation, migration, invasion, and epithelial- mesenchymal transition (EMT) of SW620 and HCT116 cells were assessed by colony formation assay, CCK-8, Transwell assay, wound healing assay, and western blot. Target prediction was performed for miR-143-5p, and a dual luciferase assay was used to verify the targeting relationship. Results: Compared to CRC cells transfected with negative controls, cell proliferation, migration and invasion, and EMT were inhibited in miR-143-5p-overexpressing cells. Expression of HMGA2 (high- mobility Group AT-Hook 2), a target gene of miR-143-5p, was repressed by miR-143-5p. Rescue experiments confirmed that upregulation of HMGA2 due to mIR-143-5p overexpression reversed inhibition of CRC cell proliferation, invasion and EMT. Conclusion: MiR-143-5p inhibits the malignant progression of CRC by regulating HMGA2 expression and is expected to provide new therapeutic approaches for clinical treatment of CRC

Knowledge, attitude, and practice of healthcare workers on early gastrointestinal cancer in China

ObjectiveGastrointestinal cancer is the leading cause of cancer-related death in China, and its early screening is largely recommended by healthcare workers. This study investigated the knowledge, attitudes, and practice (KAP) of healthcare workers on early gastrointestinal cancer (EGC).MethodsThis cross-sectional study was conducted on healthcare workers who volunteered to participate from 30 hospitals in China between September and December 2022. A self-administered questionnaire including 37 questions was developed.ResultsA total of 545 completed questionnaires were finally obtained. Healthcare workers had moderate knowledge level [9.22 ± 1.80 (65.88±12.89%), total score: 14], positive attitude [21.84 ± 2.67 (91.01 ± 11.14%), total score: 24], and excellent practice level [19.07 ± 4.43 (79.47 ± 18.44%), total score: 24] on EGC. Pearson's correlation analysis suggested that knowledge score was positively correlated with attitude (r = 0.264, P < 0.001) and practice score (r = 0.140, P = 0.001), and higher attitude score was significantly correlated with higher practice score (r = 0.380, P < 0.001), which were supported and reinforced by structural equation modeling. In addition, subgroup analysis showed that knowledge scores might be influenced by sex, age, education, type of hospital, type of occupation, professional title, and years of working (all P < 0.05); attitude scores might be influenced by years of working (P < 0.05); and practice scores were statistically distinct among groups of different sex, department, and years of working (all P < 0.05).ConclusionHealthcare workers have moderate knowledge level, positive attitude, and excellent practice levels on EGC. Good knowledge and positive attitude might be correlated with excellent practice. KAP level might be influenced by sociodemographic characteristics

Recent Progress in Flexible Pressure Sensor Arrays

Flexible pressure sensors that can maintain their pressure sensing ability with arbitrary deformation play an essential role in a wide range of applications, such as aerospace, prosthetics, robotics, healthcare, human–machine interfaces, and electronic skin. Flexible pressure sensors with diverse conversion principles and structural designs have been extensively studied. At present, with the development of 5G and the Internet of Things, there is a huge demand for flexible pressure sensor arrays with high resolution and sensitivity. Herein, we present a brief description of the present flexible pressure sensor arrays with different transduction mechanisms from design to fabrication. Next, we discuss the latest progress of flexible pressure sensor arrays for applications in human–machine interfaces, healthcare, and aerospace. These arrays can monitor the spatial pressure and map the trajectory with high resolution and rapid response beyond human perception. Finally, the outlook of the future and the existing problems of pressure sensor arrays are presented

Effect of Geometric Error on Friction Behavior of Cylinder Seals

The tribological characteristics of the cylinder directly affect the operation accuracy of the pneumatic servo system. However, the geometric error has a significant effect on its tribological behavior and the related research is insufficient. Thus, the dynamic friction process of rubber seals has been investigated considering the influence of geometric errors. Firstly, based on the self-made friction test platform, the friction force of the rubber seals was studied and the influence law of geometric error on the contact area of the rubber seal ring was revealed. Secondly, the numerical model of the friction and contact of the rubber seals for the cylinder segment was developed by using the finite element simulation method and the influence laws of machining errors, such as roundness and straightness on the friction characteristics, were revealed. Finally, synergy effects of roundness and straightness in the friction behavior of rubber seals considering geometric errors was investigated, which lays a foundation for the accurate prediction of cylinder dynamic mechanical properties

Bioinspired Spinosum Capacitive Pressure Sensor Based on CNT/PDMS Nanocomposites for Broad Range and High Sensitivity

Flexible pressure sensors have garnered much attention recently owing to their prospective applications in fields such as structural health monitoring. Capacitive pressure sensors have been extensively researched due to their exceptional features, such as a simple structure, strong repeatability, minimal loss and temperature independence. Inspired by the skin epidermis, we report a high-sensitivity flexible capacitive pressure sensor with a broad detection range comprising a bioinspired spinosum dielectric layer. Using an abrasive paper template, the bioinspired spinosum was fabricated using carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites. It was observed that nanocomposites comprising 1 wt% CNTs had excellent sensing properties. These capacitive pressure sensors allowed them to function at a wider pressure range (~500 kPa) while maintaining sensitivity (0.25 kPa−1) in the range of 0–50 kPa, a quick response time of approximately 20 ms and a high stability even after 10,000 loading–unloading cycles. Finally, a capacitive pressure sensor array was created to detect the deformation of tires, which provides a fresh approach to achieving intelligent tires

Experiment and Simulation Research on the Fatigue Wear of Aircraft Tire Tread Rubber

The road surface and the tread pattern structures directly affect the wear performance of aircraft tire, especially for lateral sliding conditions. In this paper, wear tests of tread block with different draft angles and root radiuses, different interfaces, and different slip angles were carried out, and combined with the simulation, the effects of tread groove structure and slip angle on the wear mechanism were analyzed. Results indicated that the influences of draft angle were greater than the root radius; the wear geometry of the tread block decreased when the draft angle increased in the range of 0° to 15°, but for the root radius, the wear geometry of each sample was similar to a strip shape. A considerable material loss occurred at the front edge when the slip angle increased, and the slip angle was larger in the range of 0° to 45°. Combined with the simulation and wear test, fatigue wear and abrasive wear of the slide surface are dominant factors when considering the effects of tread groove structure and slip angle, and both front edges of the tread blocks roll up repeatedly; the coefficient decreases with the increase in load when the cement concrete pavement interface is dry, but for a wet interface, the coefficient decreases softly