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To explore the vibration transmission characteristics and vibration reduction effects of metro tunnels with different track structures, the regular slab track section, the double-layer nonlinear vibration-damping fastener section and the isolated damping pad section in the Nanchang Metro Line 3 were selected respectively for the field hammer excitation test. Based on the field test results, the vibration transmission characteristics and the vibration reduction effects of metro tunnels with different track structures were analyzed. The results indicated that the vibration reduction effect of the isolated damping pads was best, followed by the double-layer nonlinear vibration-damping fasteners, while that of the regular slab tracks was worst; the double-layer nonlinear vibration-damping fastener section had obvious vibration reduction effect in the frequency range of 80 to 170 Hz, the isolated damping pad section had significant vibration reduction performance above 30 Hz; the vibration of the double-layer nonlinear vibration-damping fastener section and the isolated damping pad section was 5.6 dB and 10 dB less than the regular slab track section, respectively.

The inhibitor of apoptosis-stimulating protein of p53 (iASPP) acts as a key modulator of cellular protection against oxidative stress. In the present work, we assessed the role of iASPP in the regulation of cardiomyocyte injury induced by hypoxia/reoxygenation (H/R). We found that H/R-exposed cardiomyocytes expressed decreased levels of iASPP. The upregulation of iASPP repressed H/R-induced injury by decreasing levels of apoptosis and reactive oxygen species production. The upregulation of iASPP increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation and enhanced Nrf2 activation. The overexpression of Kelch-like ECH-associated protein 1 reversed iASPP-mediated promotion of Nrf2 activation. Nrf2 inhibition abrogated iASPP-mediated cardioprotective effects in H/R-exposed cardiomyocytes. Our work demonstrates that the upregulation of iASPP ameliorates H/R-induced apoptosis and oxidative stress in cardiomyocytes via potentiating Nrf2 signaling via modulation of Keap1.

The conventional manual approach to measurement of aortic pulse wave velocity (PWV) by Doppler ultrasonography is time consuming and operator dependent. Here we report a new semi-automated methodology for more efficient and objective measurement of aortic PWV and results of tests of its clinical feasibility and reproducibility. Carotid-femoral pulse wave velocity (cfPWV) was measured in 50 patients with suspected coronary artery disease (aged 59.2 ± 10.0 y, 36 males) by three independent observers, including two experienced sonographers and one cardiologist without ultrasonographic experience. The cfPWV measured by the semi-automatic method (cfPWVA) was compared with reference values obtained by averaging measurements by two experienced sonographers using the conventional standard manual method (cfPWVM). Measurements of cfPWVA were feasible in all 50 patients and exhibited excellent agreement with averaged cfPWVM from the two experienced sonographers, with an intraclass correlation coefficient (ICC) of 0.915 (95% confidence interval: 0.876-0.942). The inexperienced observer-measured cfPWVA did not differ from the cfPWVM measured by the two experienced sonographers (8.04 ± 1.29 vs. 8.14 ± 1.32 m/s, p > 0.05), with a high consistency by ICC of 0.877 (0.793-0.928). Bland-Altman plots further illustrated the good agreement between the two methods and good intra- and inter-observer reproducibility. Time consumption for cfPWV measurement using the new method was significantly less than that for the manual method (122 ± 35 s vs. 455 ± 105 s, p < 0.0001), saving about 73% of the time. This new semi-automatic methodology for aortic PWV measurement not only has an accuracy similar to that of the conventional standard manual method but is also highly feasible and time saving. It may provide a reliable, simple and reproducible approach to arterial stiffness evaluation in clinical settings.

A 37-year-old man was admitted to our cardiology department with sustained palpitations for 36 hours. He had suffered from paroxysmal palpitations for five years. This had happened one to three times per month, especially in the six months before admission and syncope occurred occasionally. The most useful way to terminate the acute episode of palpitations was a loading dose of propafenone (up to 210 mg). The patient had been diagnosed with dilated cardiomyopathy seven years ago by an ultrasound examination. The onset electrocardiogram (ECG) was a fast and regular rhythm with wide QRS complexes (174 beats/min). During the administration of propafenone, the following ECG was documented (figure 1). What is your diagnosis?