Objective:To investigate the effect of pulsed electric field (PEF) combined with low temperature plasma (LTP) on mouse liver cancer cell.Methods:H22 mouse liver cancer cells were divided into liver cancer group, PEF treatment group, LTP treatment group, combined group A (first PEF treatment immediately after LTP treatment), combined group B (first LTP treatment immediately after PEF treatment), combined group C (same as combined group A, but 20 minutes interval) and combined group D (same as combined group B, but 20 minutes interval). Cell viability was detected by cell counting, apoptosis was detected by flow cytometry, intracellular reative oxygen species (ROS) was marked by fluorescence and counted. Twenty healthy female Kunming mouse aged 4-6 weeks without specific pathogens were subcutaneous injected with liver cancer cells, and then were randomly divided into model group, PBS control group, PEF experimental group, LTP experimental group and combined group (LTP+ PEF, no interval) ( n=4). Tumor relative volume and tumor inhibition rate were measured. Results:The survival rates were liver cancer cell group (98.3±0.9)%, PEF treatment group (66.8±4.4)%, LTP treatment group (62.1±3.9)%, combined group A (43.7±3.7)%, combined group B (31.0±1.4)%, combined group C (46.8±2.9)%, combined group D (39.0±2.3)%. Compared with liver cancer cell group, the cell survival rate of all treatment groups was decreased, and the cell survival rate of the four combined treatment group was lower than that of PEF treatment group and LTP treatment group, the differences were statistically significant (all P<0.05). The survival rate of combined B group was the lowest. The results of apoptosis detection were consistent with those of cell survival rate. Under fluorescence microscope, the ROS fluorescence of cells in the combined group B was significantly increased, and the ROS fluorescence of cells in the LTP treatment group was more than that in the PEF treatment group, and the percentage of ROS positive cells in the combined group B was higher than that in the LTP treatment group and the PEF treatment group, with statistical significance (all P<0.05). Tumor relative volume and tumor inhibition rate in the combined group were better than those in the PEF and LTP groups, and the differences were statistically significant (all P<0.05). Conclusion:LTP combined with PEF has a better killing effect on H22 cells than PEF or LTP treatment, which is expected to be a new tumor therapy.

Objective    To investigate the feasibility of using magnetic beads to locate small pulmonary nodules. Methods    Twelve rabbits were randomly divided into two groups, 6 in each group. One group underwent thoracotomy after anesthesia and the other group underwent percutaneous puncture under the guidance of X-ray. One and two cylindrical tracer magnets (magnetic beads) with a diameter of 1 mm and a height of 3 mm were injected adjacent to the imaginary pulmonary nodules in left lung in each group. The magnetic beads beside the imaginary nodules were attracted by a pursuit magnet with a diameter of 9 mm and a height of 19 mm. The effectiveness of localization by magnetic beads were determined by attraction between tracer and pursuit magnets. Results    All processes were uneven in 12 rabbits. There was micro hemorrhage and no hematoma in the lung tissue at the injection site of the magnetic beads. When tracked with the pursuit magnets, there was one bead divorce in cases that one bead was injected, but no migration or divorce of the magnetic beads in cases that two magnetic beads were simultaneously injected to localize the small pulmonary nodules. Conclusion    The feasibility of using magnetic beads to locate small pulmonary nodules has been  preliminarily verified.