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Objective To study the effects of ropivacaine on the biological behaviour of liver cancer cell line Hep3B and to explore its molecular mechanism. Methods Hep3B cells were divided into the control group, ropivacaine group, si-NC group, si-LINC00853 group, pcDNA-NC group, pcDNA-LINC00853 group,(ropivacaine+pcDNA-NC) group and (ropivacaine +pcDNA-LINC00853) group. Cell Counting Kit(CCK-8), Transwell assays, and RT-qPCR were applied to detect cell proliferation, migration, invasion and LINC00853 expression. Western blot was used to analyze the expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2(MMP2) and MMP9 proteins. Results Compared with the NC group, the proliferation inhibition rate of Hep3B cells in the ropivacaine group was elevated, cell migration and invasion were inhibited. The expression of PCNA, MMP2, MMP9 and LINC00853 was reduced (P＜0.05). Compared with the si-NC group, the proliferation inhibition rate of Hep3B cells in the si-LINC00853 group was elevated, cell migration and invasion were reduced and the expression of PCNA, MMP2, MMP9 protein was decreased (P＜0.05). Compared with the pcDNA-NC group, the proliferation inhibition of Hep3B cells in the pcDNA-LINC00853 group was reduced, cell migration and invasion were increased. The expression of PCNA, MMP2, and MMP9 protein was increased (P＜0.05). Compared with the (ropivacaine+ pcDNA-NC) group, the proliferation inhibitio of Hep3B cells in the (ropivacaine+ pcDNA-LINC00853) group was reduced, cell migration and invasion were increased and the expression of PCNA, MMP2 and MMP9 protein increased (P＜0.05). Conclusions Ropivacaine can inhibit liver cancer cell line Hep3B proliferation, migration and invasion. Its mechanism may be related to the down-regulation of LINC00853 expression.

A negative corona discharge system of a needle-plate electrode suitable for sub-millimeter gaps is established to investigate Trichel pulse characteristics of negative corona discharge, in which an optical acquisition system is especially applied to timely observe a discharging corona. Electrostatics–hydrodynamics coupling simulations of air discharging in 100 μm-gaped needle-plate electrodes are performed to elucidate the micro-physical process of negative corona discharge. The impact ionization coefficient used for simulations and the experimentally recorded images of discharge corona are combined to characterize the active region of secondary electron emission. Dynamical distribution and transport of the charged particles are analyzed from multiphysics simulations to explain the microscopic mechanism for various stages of Trichel pulses. Even though the corona front near the plate electrode maintains a high rate of collision ionization and secondary electron excitation, the needle tip corona has not reached the threshold electric field of electron avalanche required for glow discharge, as manifested by discharge sawtooth waves comprised of corona and glow components. The amplitude and frequency of Trichel pulses increase, respectively, with impact ionization and secondary electron emission, which is evidently dependent on attachment coefficient and anion mobility. A higher attachment coefficient will lead to a significant reduction in amplitude of Trichel pulses. The present study provides a theoretical basis and experimental verification for micrometer discharges, which is the key point of insulation protections in microelectromechanical systems. [ABSTRACT FROM AUTHOR]