MiR-196b-5p regulates the proliferation of drug-resistant hepatocellular carcinoma cell lines by activating NFκB/ABCB1 signaling pathway

Purpose: To explore the molecular function of miR-196b-5p in hepatocellular carcinoma (HCC).Methods: MiR-196b-5p expression levels in HCC tissue samples were assessed by qRT-PCR. MiR-196b-5p was knocked-down or over-expressed in HepG2 cells by transfecting the cells with plasmids expressing either a miR-196b-5p inhibitor or mimic, respectively, while cell proliferation was  assessed by MTT assay. The interaction of miR-196b-5p with target molecules was confirmed using luciferase reporter assay. Cell cycle was investigated by flow cytometry, while NFκBIA expression was assessed by western blotting.Results: MiR-196b-5p was over-expressed in HCC, and miR-196b-5p expression levels in patients with HCC were related to tumor grade. MiR-196b-5p over-expression promoted cell proliferation and colony formation and suppressed cell cycle arrest and apoptosis. The results of luciferase reporter assay showed that miR-196b-5p reduced NFκBIA expression in HepG2 cells by binding to a response element in the 3′ UTR of NFκBIA. Further investigation showed that NFκBIA interacts with NFκB1 and reduces the concentration of NFκB1 in HepG2 cells. The promoter of ATP-binding cassette sub-family B member 1 (ABCB1) was also targeted and bound by NFκB1, which altered the expression of ABCB1 in HepG2 cells.Conclusion: MiR-196b-5p regulates cell proliferation in drug-resistant HCC cell lines via activation of the NFκB/ABCB1 signaling pathway. Keywords: Hepatocellular carcinoma, miR-196b-5p, NFκBIA, NFκB1, ABCB

Optimization of Multi-zone Cooling System of Complex Pipe Network Based on Particle Swarm and Genetic Algorithm

The cooling pipe network system of the power plant has the characteristics of multiple users, multiple working conditions, and complex topological structure. The division of water supply to the pipe network can simplify the topological structure of the pipe network, facilitate flow regulation, and adapt to the requirements of multiple working conditions. District water supply can be divided into districts according to flow, pressure and structure. The user allocation of pipe network water supply system is a typical combined optimization problem. When the system is relatively complex and the number of users is huge, conventional enumeration methods, dynamic programming and other methods are often unable to solve such problems. The combined algorithm of particle swarm algorithm and genetic algorithm can obtain approximate solutions to such problems. By using a combination of particle swarm algorithm and genetic algorithm to analyze and determine the distribution of pipe network user traffic, it is possible to avoid the waste of energy in the distribution of pipe network users based on experience. The combined algorithm proposed in this paper has high stability, can change the number of partitions to adjust user allocation according to actual needs, and has strong versatility. For the case described in this article, when the number of partitions is 2, compared to the cases where the number of partitions is 3 and 4, the flow rate and pressure drop of each partition are not much different, which can better meet the reliability and maintainability requirement

Numerical Simulation on Two-Phase Ejector with Non-Condensable Gas

The two-phase ejector is a simple and compact pressure boosting device and widely used in ejector steam-generator water feeding systems and core emergency cooling systems. The direct contact condensation of water and steam is the key process of a two-phase ejector. Usually, the high-temperature and high-pressure steam will inevitably induce non-condensable gases. The existence of non-condensable gases will reduce the condensation heat transfer rate between steam and water, and harm the equipment. This study carried out 3D numerical simulations of a two-phase ejector based on an inhomogeneous multiphase model. The steam inlet pressure and the non-condensable gas mass fraction rang in 0.6–2.9 MPa and 1–10%, respectively. The heat and mass transfer characteristics were analyzed under different conditions. The results show that the heat transfer coefficient and plume penetration length increased with the steam inlet pressure. Non-condensable gas prevents direct contact condensation between the steam and water. The non-condensable gas mass fraction rises from 1% to 10%, the heat transfer between steam and water deteriorates, and leads to a lower heat transfer coefficient

Design Improvement of Four-Strand Continuous-Casting Tundish Using Physical and Numerical Simulation

The flow pattern is vital for the metallurgical performance of continuous casting tundishes. The purpose of this study was to design and optimize the flow characteristics inside a four-strand tundish. Numerical simulations and water model experiments were validated and utilized to investigate the flow behavior. The effect of different flow rates in the original tundish was evaluated; two modified retaining walls and a new ladle shroud were designed for optimization. The molten steel inside the original tundish tends to be more active as the flow rate increases from 3.8 L/min to 6.2 L/min, which results in a reduction in dead volume from 36.47% to 17.59% and better consistency between different outlets. The dead volume and outlet consistency inside the tundish are improved significantly when the modified walls are applied. The proper design of the diversion hole further enhances the plug volume from 6.39% to 13.44% of the tundish by forming an upstream circular flow in the casting zone. In addition, the new trumpet ladle shroud demonstrates an advantage in increasing the response time from 152.5 s to 167.5 s and alleviating the turbulence in the pouring zone, which is beneficial for clean steel production

CFD Simulation on Pressure Profile for Direct Contact Condensation of Steam Jet in a Narrow Pipe

In the published experimental results, it has been observed that when high-speed steam spurt into the subcooled waterflow, the total pressure along the axial direction at trailing edge of the steam plume shows a pressure-lift. To reveal the mechanism behind this phenomenon, this study utilizes a particle model to investigate the pressure profile of steam jet condensation in subcooled water flow in a narrow pipe. A numerical model based on the Eulerian–Eulerian multiphase model has been developed to accurately simulate the characteristics of pressure profile along the axial direction. The model’s validity is established by comparing the steam plume shape and temperature profiles with the experimental data. By analyzing the total pressure profile of the axis and the contours of gas volume fraction, it is found that there exists a pressure-lift phenomenon at trailing edge of the steam plume. The dynamic pressure of the water also shows a pressure-lift at this position, so it can be inferred that the dynamic pressure of the water is the main factor of the total pressure-lift