12 research outputs found

    A novel semi-active suspension design based on decoupling skyhook control

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    A semi-active suspension design based on the traditional method of skyhook control is not capable of effectively controlling the attitude of the vehicle. However, an innovative approach called decoupling skyhook control allows the attitude of the vehicle body and its vibration characteristics to be effectively controlled. In this paper, a new decoupling skyhook controller for semi-active suspension is presented. Vehicle body motions in the three directions of vertical, pitch, and roll have been adopted to develop three skyhook controllers and directly control the vehicle body attitude. Furthermore, three orientation skyhook control forces are converted into actual damping forces of four adjustable dampers through the input decoupling transformation. The simulation results show that the developed controller is more effective than the traditional skyhook control in improving ride comfort

    A novel semi-active suspension design based on decoupling skyhook control

    Get PDF
    A semi-active suspension design based on the traditional method of skyhook control is not capable of effectively controlling the attitude of the vehicle. However, an innovative approach called decoupling skyhook control allows the attitude of the vehicle body and its vibration characteristics to be effectively controlled. In this paper, a new decoupling skyhook controller for semi-active suspension is presented. Vehicle body motions in the three directions of vertical, pitch, and roll have been adopted to develop three skyhook controllers and directly control the vehicle body attitude. Furthermore, three orientation skyhook control forces are converted into actual damping forces of four adjustable dampers through the input decoupling transformation. The simulation results show that the developed controller is more effective than the traditional skyhook control in improving ride comfort

    A novel semi-active suspension design based on decoupling skyhook control

    Get PDF
    A semi-active suspension design based on the traditional method of skyhook control is not capable of effectively controlling the attitude of the vehicle. However, an innovative approach called decoupling skyhook control allows the attitude of the vehicle body and its vibration characteristics to be effectively controlled. In this paper, a new decoupling skyhook controller for semi-active suspension is presented. Vehicle body motions in the three directions of vertical, pitch, and roll have been adopted to develop three skyhook controllers and directly control the vehicle body attitude. Furthermore, three orientation skyhook control forces are converted into actual damping forces of four adjustable dampers through the input decoupling transformation. The simulation results show that the developed controller is more effective than the traditional skyhook control in improving ride comfort

    Neuroprotective Effect of Ulinastatin on Spinal Cord Ischemia-Reperfusion Injury in Rabbits

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    Ulinastatin (UTI), a trypsin inhibitor, is isolated and purified from human urine and has been shown to exert protective effect on myocardial ischemia reperfusion injury in patients. The present study was aimed at investigating the effect of ulinastatin on neurologic functions after spinal cord ischemia reperfusion injury and the underlying mechanism. The spinal cord IR model was achieved by occluding the aorta just caudal to the left renal artery with a bulldog clamp. The drugs were administered immediately after the clamp was removed. The animals were terminated 48 hours after reperfusion. Neuronal function was evaluated with the Tarlov Scoring System. Spinal cord segments between L2 and L5 were harvested for pathological and biochemical analysis. Ulinastatin administration significantly improved postischemic neurologic function with concomitant reduction of apoptotic cell death. In addition, ulinastatin treatment increased SOD activity and decreased MDA content in the spinal cord tissue. Also, ulinastatin treatment suppressed the protein expressions of Bax and caspase-3 but enhanced Bcl-2 protein expression. These results suggest that ulinastatin significantly attenuates spinal cord ischemia-reperfusion injury and improves postischemic neuronal function and that this protection might be attributable to its antioxidant and antiapoptotic properties

    Different Effects of Pro‐Inflammatory Factors and Hyperosmotic Stress on Corneal Epithelial Stem/Progenitor Cells and Wound Healing in Mice

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    Abstract Chronic inflammation and severe dry eye are two important adverse factors for the successful transplant of cultured limbal stem cells. The aim of this study was to investigate the effects of inflammation and hyperosmotic stress (a key pathological factor in dry eye) on corneal epithelial stem cells (CESCs) and corneal epithelial wound healing. We observed that the CESCs exhibited significant morphological changes when treated with interleukin‐1 beta (IL‐1ÎČ), tumor necrosis factor alpha (TNF‐α), or hyperosmotic stress. Colony‐forming efficiency or colony‐forming size was decreased with the increasing concentrations of IL‐1ÎČ, TNF‐α, or hyperosmotic stress, which was exacerbated when treated simultaneously with pro‐inflammatory factors and hyperosmotic stress. However, the colony‐forming capacity of CESCs recovered more easily from pro‐inflammatory factor treatment than from hyperosmotic stress treatment. Moreover, when compared with pro‐inflammatory factors treatment, hyperosmotic stress treatment caused a more significant increase of apoptotic and necrotic cell numbers and cell cycle arrest in the G2/M phase. Furthermore, the normal ability of corneal epithelial wound healing in the mice model was suppressed by both pro‐inflammatory factors and hyperosmotic stress treatment, and especially severely by hyperosmotic stress treatment. In addition, inflammation combined with hyperosmotic stress treatment induced more serious epithelial repair delays and apoptosis in corneal epithelium. Elevated levels of inflammatory factors were found in hyperosmotic stress‐treated cells and mice corneas, which persisted even during the recovery period. The results suggested that pro‐inflammatory factors cause transient inhibition, while hyperosmotic stress causes severe apoptosis and necrosis, persistent cell cycle arrest of CESCs, and severe corneal wound healing delay. Stem Cells Translational Medicine 2019;8:46–5

    An Ultrasensitive Diagnostic Biochip Based on Biomimetic Periodic Nanostructure-Assisted Rolling Circle Amplification

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    Developing portable and sensitive devices for point of care detection of low abundance bioactive molecules is highly valuable in early diagnosis of disease. Herein, an ultrasensitive photonic crystals-assisted rolling circle amplification (PCs-RCA) biochip was constructed and further applied to circulating microRNAs (miRNAs) detection in serum. The biochip integrated the optical signal enhancement capability of biomimetic PCs surface with the thousand-fold signal amplification feature of RCA. The biomimetic PCs displayed periodic dielectric nanostructure and significantly enhanced the signal intensity of RCA reaction, leading to efficient improvement of detection sensitivity. A limit of detection (LOD) as low as 0.7 aM was obtained on the PCs-RCA biochip, and the LOD was 7 orders of magnitude lower than that of standard RCA. Moreover, the PCs-RCA biochip could discriminate a single base variation in miRNAs. Accurate quantification of ultralow-abundance circulating miRNAs in clinical serum samples was further achieved with the PCs-RCA biochip, and patients with the nonsmall cell lung carcinoma were successfully distinguished from healthy donors. The PCs-RCA biochip can detect bioactive molecules with ultrahigh sensitivity and good specificity, making it valuable in clinical disease diagnosis and health assessment
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