ABSTRACT
OBJECTIVE: To analyze the effect of multidimensional comprehensive intervention on medication compliance, social function and incidence of major adverse cardiovascular events (MACE) in patients undergoing percutaneous coronary intervention (PCI). METHODS: Ninety-eight patients with coronary heart disease (CHD) who underwent PCI in our hospital were selected and divided into the regular group (n=46, receiving regular nursing intervention) and the comprehensive group (n=52, receiving multidimensional comprehensive nursing intervention) according to the different nursing intervention methods. The medication compliance, social function, quality of life, and incidence of MACE were compared between the two groups. RESULTS: The comprehensive group showed significantly higher rates of taking medication on time, taking medication according to the proper amount, taking medication at the recomended times, no increase or decrease in the amount of medication, and taking medication without interruption than the regular group (P < 0.05). The comprehensive group exhibited significantly higher scores of medication compliance than the regular group (P < 0.05). The Social Disability Screening Schedule (SDSS) scores of both groups during intervention for 8 weeks were lower than those before intervention and after intervention for 2 and 4 weeks (P < 0.05). The SDSS scores of intervention for 2, 4, and 8 weeks in the comprehensive group were significantly lower than that in the regular group (P < 0.05). After intervention, the comprehensive group showed significantly higher scores of physiological function, psychological function, cognitive function, emotional function, role function, and total quality of life than the regular group (P < 0.05). The incidence of MACE in the comprehensive group was significantly lower than that in the regular group (P < 0.05). CONCLUSION: The use of multidimensional comprehensive intervention for patients undergoing PCI can effectively improve patients' medication compliance, social function and quality of life, and reduce the incidence of MACE.
ABSTRACT
In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress-strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress-strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress-strain characteristics of filled rubber.
ABSTRACT
Rubber-based materials are widely used in a variety of industrial applications. In these applications, rubber components withstand various loading conditions over a range of temperatures. It is of great significance to study the mechanical behavior of vulcanized rubber at different temperatures, especially in a range of high temperatures. The temperature dependence of the constitutive behavior of filled rubber is important for the performance of the rubber. However, only a few constitutive models have been reported that investigate the stress-temperature relationship. In this paper, based on an analysis of experimental data, the effects of temperature on the hyperelastic behaviors of both natural rubber and filled rubber, with different mass fractions of carbon black, were studied. The regulation of stress and strain of natural rubber and filled rubber with temperature was revealed. In addition, an eight-chain model that can reasonably characterize the experimental data at different temperatures was proved. An explicit temperature-dependent constitutive model was developed based on the Arruda-Boyce model to describe the stress-strain response of filled rubber in a relatively large temperature range. Meanwhile, it was proved that the model can predict the effect of temperature on the hyperelastic behavior of filled rubber. Finally, the improved Arruda-Boyce model was used to obtain the material parameters and was then successfully applied to finite element analysis (FEA), which showed that the model has high application value. In addition, the model had a simple form and could be conveniently applied in related performance test of actual production or finite element analysis.
