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This paper proposes a control method for improving the dynamic characteristic of battery chargers for personal mobility devices (PMDs) using sliding mode control (SMC). Various types of PMDs have batteries with distinct voltages. Therefore, research on battery chargers for PMDs that can be applied to various types of PMD with distinct voltages has been actively pursued. In battery chargers for PMDs, the output voltage can usually be controlled by a proportional-integral (PI) controller. However, increasing the PI controller gain is necessary to enhance the dynamic characteristic of the output voltage. It results in an overshoot that adversely affects the stability of the battery charger. Therefore, in this paper, a control method using sliding mode control (SMC) is presented for improving the dynamic characteristic without overshoot in the output voltage of battery chargers for PMDs. The validity of the proposed control method is verified by the simulation and experimental results. [ABSTRACT FROM AUTHOR]

Purpose: Anticancer chemotherapy usually involves the administration of several anticancer drugs that differ in their action mechanisms. Here, we aimed to test whether the combination of omacetaxine mepesuccinate (OMT) and doxorubicin (DOX) could show synergism, and whether the liposomal co-delivery of these two drugs could enhance their antitumor effects in cervical carcinoma model. Method: OMT-loaded liposomes (OL) were prepared by loading the drug in the lipid bilayers. OL were then electrostatically complexed with DOX, yielding double-loaded liposomes (DOL). DOX-loaded liposomes (DL) were formulated by electrostatic interaction with negatively charged empty liposomes (EL). The combination index (CI) values were calculated to evaluate the synergism of two drugs. In vitro antitumor effects against HeLa cells were measured using CCK-8, calcein staining, and crystal violet staining. In vivo antitumor effects of various liposomes were tested using HeLa cell-bearing mice. Results: Combination of DOX and OMT had ratio-dependent synergistic activities, with very strong synergism observed at a molar ratio of 4:1 (DOX:OMT). The sizes of EL, DL, OL, and DOL did not significantly differ, but the zeta potentials of DL and DOL were slightly higher than those of OL and EL. In vitro, DOL showed higher antitumor activity than OL, DL or EL in cervical carcinoma HeLa cells. In vivo, unlike other liposomes, DOL reduced the tumor growths by 98.6% and 97.3% relative to the untreated control on day 15 and 25 after the cessation of treatment, respectively. Conclusions: These results suggest that liposomal co-delivery of DOX and OMT could synergistically potentiate antitumor effects. [ABSTRACT FROM AUTHOR]