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A braking control system is an essential part of urban rail vehicle braking systems. Due to the uncertainty of operational data, direct analysis can affect the authenticity of system reliability. To solve the deviation of system reliability analysis caused by uncertainty, GO Methodology is combined with fuzzy theory to establish the GO graph model of the system according to the characteristics of the braking control system. The membership function of the fuzzy success rate of the system is obtained by using the modified signal flow calculation method combined with the fuzzy number algebraic calculation method, and the system fuzzy success rate with high reliability is selected. The calculated results can provide guidance and suggestions for system maintenance, and they have strong engineering practicability. [ABSTRACT FROM AUTHOR]

Contact fatigue is one of the main causes of the failure of gear transmission systems. Considering the gear separation phenomenon, a contact damage-torsional vibration coupling dynamic model is proposed with nonlinear backlash, time-varying meshing stiffness, contact stress model, and contact damage model based on gear contact geometry, S-N curve, and reliability theory. Using the model established, the numerical simulation is investigated to analyze the degradation process of the gear system under a fixed-speed condition. The research results show that the degradation process of gear contact fatigue has a non-linear relation with rotational speed and rotation cycle. The contact stress shows that there is no obvious gear separation phenomenon at n = 1000 and n = 3000, but there are obvious gear separation phenomena at n = 2000. The remaining useful life of gear teeth changes more violently and the total life is lowest at n = 2000. [ABSTRACT FROM AUTHOR]

Exercise induces the expression of peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α ) in skeletal muscle, which promotes the cleavage of fibronectin type III domain-containing protein 5 (FNDC5) to irisin. To explore the relationship between irisin and its regulators, we analyzed the plasma irisin levels and the muscle levels of FNDC5 and PGC-1α after exercise. Male C57BL/6J mice underwent a treadmill exercise (60% of VO2max) for 30 min or one hour (h), and blood and gastrocnemius samples were collected before exercise (pre-exercise), immediately after exercise, and during 24-h recovery after 1-h exercise. We found that plasma irisin levels were significantly increased during exercise (P < 0.05), while FNDC5 protein levels were not significantly increased. Moreover, PGC-1α mRNA and protein levels were significantly increased during 30-min exercise, but were decreased during 1-h exercise. After 1-h exercise, the irisin levels peaked at 6 h (20.71 ± 0.25 ng/ml) and decreased to pre-exercise levels by 24 h (15.45 ± 0.27 ng/ml). Likewise, PGC-1α mRNA and protein levels were increased at 1 h and maintained at elevated levels for 6 h; thereafter, the expression levels of PGC1-α protein were decreased to pre-exercise levels at 12 h. Thus, the restoration of PGC-1α expression to the pre-exercise levels was followed by the decrease in plasma irisin levels. By contrast, during 24-h recovery, the expression levels of FNDC5 mRNA and protein were maintained at elevated levels. These results suggest that the coordinated expression of FNDC5 and PGC-1α may contribute to the increased levels of plasma irisin after exercise. [ABSTRACT FROM AUTHOR]

People living with HIV or AIDS (PLWHA) experienced severe medical discrimination which is seriously affecting their lives. However, few studies examined the epidemic characteristics of self-perceived medical discrimination from the discrimination objects such as PLWHA. Therefore, we aimed to investigate the epidemiological status and analyze the influential factors of the self-perceived medical discrimination on PLWHA in South China. The self-designed questionnaire was used to investigate the medical discrimination status of the 443 infected persons, who were randomly recruited from the representative AIDS designated hospitals in Guangdong Province in South China. The results showed that 49.0% of PLWHA experienced medical discrimination, and 55.3% received discriminatory treatment, 48.4% experienced refusal of treatment, 36.4% had private information leaked and 12.9% received mandatory test. However, 52.2% patients chose to endure discrimination in silence. Compared with the Asymptomatic HIV-infected patients, AIDS patients perceived more medical discrimination. The Logistic regression analysis indicated that PLWHA self-perceived medical discrimination status was influenced by 4 factors: the voluntary of first medical detection, the route of transmission, the stage of the disease and the familiarity with the HIV/AIDS-related law. Additionally, the two dimensions of the life quality scale were influenced by medical discrimination, namely, overall function and disclosure worry. Ultimately, our study provides a better understanding of the relationship between infection status, quality of life and the medical discrimination they experienced or perceived. It will help health professionals and policy makers to develop tailored behavioral and policy-oriented intervention strategies for PLWHA to tackle different types of medical discrimination in high-risk settings. [ABSTRACT FROM AUTHOR]