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Aim: In this study, we investigated the effect of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio on restenosis status in patients undergoing carotid angioplasty stenting (CAS). Methodology & results: Clinical imageology and receiver operating characteristic analysis were utilized to study the prognostic significance of NLRs/platelet-to-lymphocyte ratios and their correlation with survival. NLR of restenosis (+) patients was evidently increased after the CAS procedures, while the NLR of restenosis (-) patients before the CAS procedures being the lowest. Area under the curve of pre-CAS NLR or/and post-CAS NLR were all evidently higher than 50%. Also, restenosis incidence was the highest in patients with both high pre-CAS and high post-CAS values. Conclusion: Therefore, NLR can be utilized as an independent prognostic indicator to predict the incidence of restenosis after CAS procedures.

The pre-charged capacitor method, used in the active current injection circuit breaker in DC system, is an effective approach to realize the current injection. However, in practical applications, the performances of post-arc among different opening speed are still unknown, which have been an obstacle that blocks the design of MV DCCB. To solve this problem, high resolution measuring equipment was used to investigate the performances of vacuum circuit breaker in post-arc period. The experimental results show that the peak value of the post-arc current can be up to 6A and the post-arc current decays to zero within 10μs after current-zero. Besides, with the increase of opening speed, the fluctuation of post-arc charge increases continuously, while the average remains basically unchanged.

Carbon dioxide (CO2) is a promising alternative to sulfur hexafluoride for high-voltage circuit breaker applications. It is important to have a detailed understanding of CO2 arc properties. In this paper, radial temperature distribution of the free burning direct current arc in pure CO2 was investigated. Optical emission spectrometry was applied under different pressures (0.5 atm, 1 atm, and 1.5 atm) and at different axial positions (1 mm, 2 mm, 3 mm above the cathode). Assuming local thermodynamic equilibrium, the Fowler–Milne method was adopted for O I 715.67 nm and O I 777.19 nm in the periphery of the arc, and the single-line method was adopted for C II 657.81 nm near the center of the arc. Radial temperature profiles obtained by these two methods were combined at the position where normal temperature was assigned. The results indicate that near the center of the arc, higher pressure would lead to lower temperature; as the distance from the cathode to the position measured increases, the maximum temperature in the arc center would decrease. In addition, the temperature would decrease more sharply toward the periphery if the central temperature of the arc is higher.