Potential Therapeutic Efficacy of Curcumin in Liver Cancer

Dai, Xin-Zheng,Yin, Hai-Tao,Sun, Ling-Fei,Hu, Xiang,Zhou, Chong,Zhou, Yun,Zhang, Wei,Huang, Xin-En,Li, Xiang-Cheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Purpose: Liver cancer, one of the most common cancers in China, is reported to feature relatively high morbidity and mortality. Curcumin (Cum) is considered as a drug possessing anti-angiogenic, anti-inflammation and anti-oxidation effect. Previous research has demonstrated antitumor effects in a series of cancers. Materials and Methods: In this study the in vitro cytotoxicity of Cum was measured by MTT assay and pro-apoptotic effects were assessed by DAPI staining and measurement of caspase-3 activity. In vivo anti-hepatoma efficacy of Cum was assessed with HepG2 xenografts. Results: It is found that Cum dose-dependently inhibited cell growth in HepG2 cells with activation of apoptosis. Moreover, Cum delayed the growth of liver cancer in a dose-dependent manner in nude mice. Conclusions: Cum might be a promising phytomedicine in cancer therapy and further efforts are needed to explore this therapeutic strategy.

Chk2 Regulates Cell Cycle Progression during Mouse Oocyte Maturation and Early Embryo Development

Dai, Xiao-Xin,Duan, Xing,Liu, Hong-Lin,Cui, Xiang-Shun,Kim, Nam-Hyung,Sun, Shao-Chen Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.2

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-metaphase I (Pro-MI), and localized to spindle poles at metaphase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibition. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at centromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromosome misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein ${\gamma}$-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

Uncertainty Modeling and Robust Control for LCL Resonant Inductive Power Transfer System

Xin Dai,Yang Zou,Yue Sun 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5

The LCL resonant inductive power transfer (IPT) system is increasingly used because of its harmonic filtering capabilities, high efficiency at light load, and unity power factor feature. However, the modeling and controller design of this system become extremely difficult because of parameter uncertainty, high-order property, and switching nonlinear property. This paper proposes a frequency and load uncertainty modeling method for the LCL resonant IPT system. By using the linear fractional transformation method, we detach the uncertain part from the system model. A robust control structure with weighting functions is introduced, and a control method using structured singular values is used to enhance the system performance of perturbation rejection and reference tracking. Analysis of the controller performance is provided. The simulation and experimental results verify the robust control method and analysis results. The control method not only guarantees system stability but also improves performance under perturbation.

Flow analysis of the baffle structure of a scrubber for small marine engines

Dai Xin,Kweon-Ha Park 한국마린엔지니어링학회 2018 한국마린엔지니어링학회지 Vol.42 No.5

Stability Analysis and Incipient Fault Tolerant Control for Multiple-output Wireless Power Transfer Systems

Xin Dai,Xingxing Hua,Shaoxin Sun,Yue Sun 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper investigates the incipient fault diagnosis problem of the multiple-output wireless power transfer system (MWPTS). And the MWPTS described in this paper has nonlinearity and high-order characteristics. Firstly, based on the Kirchhoff theorem and the interconnect system modeling method, a more realistic dynamics model of MWPTS with incipient faults, parameter uncertainty, and time delay is established. The proposed modeling method dramatically reduces the order of MWPTS. Then, a novel observer-based control strategy is proposed to estimate incipient faults while keeping the system stable even if MWPTS are affected by time delay and parameter uncertainty. Finally, the simulation result verified the availability of the incipient fault-tolerant method.

Uncertainty Modeling and Robust Control for LCL Resonant Inductive Power Transfer System

Dai, Xin,Zou, Yang,Sun, Yue The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5

The LCL resonant inductive power transfer (IPT) system is increasingly used because of its harmonic filtering capabilities, high efficiency at light load, and unity power factor feature. However, the modeling and controller design of this system become extremely difficult because of parameter uncertainty, high-order property, and switching nonlinear property. This paper proposes a frequency and load uncertainty modeling method for the LCL resonant IPT system. By using the linear fractional transformation method, we detach the uncertain part from the system model. A robust control structure with weighting functions is introduced, and a control method using structured singular values is used to enhance the system performance of perturbation rejection and reference tracking. Analysis of the controller performance is provided. The simulation and experimental results verify the robust control method and analysis results. The control method not only guarantees system stability but also improves performance under perturbation.

Analytical Solution of Magnetic Field in Permanent-Magnet Eddy-Current Couplings by Considering the Effects of Slots and Iron-Core Protrusions

Xin Dai,Qinghua Liang,Chao Ren,Jiayong Cao,Jinqiu Mo,Shigang Wang 한국자기학회 2015 Journal of Magnetics Vol.20 No.3

In this study, we propose an analytical model for studying magnetic fields in radial-flux permanent-magnet eddy-current couplings by considering the effects of slots and iron-core protrusions on the eddy currents. We focus on the analytical prediction of the air-gap field by considering the influence of eddy currents induced in conducting bars. In the proposed model, the permanent magnet region is treated as the source of a timevarying magnetic field and the moving-conductor eddy current problem is solved based on the resolution of time-harmonic Helmholtz equations. The spatial harmonics in the air gap and in slots, as well as the time harmonics are all considered in the analytical calculation. Based on the proposed field model, the electromagnetic torque is computed by using the Maxwell stress tensor method. Nonlinear finite element analysis is performed to validate the analytical model. The proposed model can be used for permanent-magnet eddy-current couplings with any slot?pole combination.

Percutaneous Radiofrequency Ablation Guided by Contrast-enhanced Ultrasound in Treatment of Metastatic Hepatocellular Carcinoma after Liver Transplantation

Dai, Xin,Zhao, Hong-Qiang,Liu, Run-Hao,Xu, Chang-Tao,Zheng, Fang,Yu, Li-Bao,Li, Wei-Min Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

This study evaluated the advantages and applications of contrast-enhanced ultrasound (CEUS)-supported percutaneous radiofrequency ablation (RFA) in the treatment of metastatic hepatocellular carcinoma after liver transplantation, based on clinical details. CEUS-supported percutaneous RFA was adopted to treat 12 patients with hepatic metastatic carcinomas after liver transplantation. The diameters of the metastatic carcinomas varied from 1 cm to 5 cm, and the foci were discovered after 3 months to 12 months. Each focus was diagnosed and localised by CEUS for RFA once or twice. Curative effects were evaluated by CEUS or contrast-enhanced CT after the treatment. The re-examination results at 2 weeks post-treatment showed that the foci of 11 patients were ablated completely, whereas one patient with the largest focus required retreatment by RFA because of a partial residue. No local recurrence was found one month later in the re-examination. CEUS-supported percutaneous RFA in the treatment of hepatic metastatic carcinoma after liver transplantation has the advantages of accurate localisation, good efficacy, easy operation, and minimal invasion without any complications. Therefore, it can be recommended as the preferred therapy for hepatic metastatic carcinoma after liver transplantation.

Effects of number and location of nozzles on flow characteristics in vertical scrubber

Dai Xin,김종호,Yongcheng Liang,박권하 한국마린엔지니어링학회 2019 한국마린엔지니어링학회지 Vol.43 No.2

The allowable emission limit of sulfur oxides from ships was reduced to 0.1% in emission control areas and will be reduced to 0.5% in other areas from 2020. Many technologies have been developed for satisfying sulfur oxide emission limits. A wet scrubber device is being developed as the preferred technology. In this study, a small vertical wet scrubber was examined for high-speed small engines. The effects of the number and location of nozzles on cleaning water distribution and flow distance were investigated. Regarding the nozzle location, the cleaning water distributions and flow distances in the scrubber were better with horizontal nozzles than with vertical nozzles. Regarding the number of nozzles in the scrubber, six yielded the best results.

Chk2 Regulates Cell Cycle Progression during Mouse Oocyte Maturation and Early Embryo Development

Xiao-Xin Dai,Xing Duan,Honglin Liu,최향순,Nam-Hyung Kim,Shao-Chen Sun 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.2

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-meta-phase I (Pro-MI), and localized to spindle poles at meta-phase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibi-tion. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at cen-tromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromo-some misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein γ-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.