The Development of High-Current Power Supply System for Electrolytic Copper Foil

An Luo,Fujun Ma,Qiaopo Xiong,Zhixing He 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

A 6.5 V/50 kA high-frequency switching power supply (HSPS) system composed of 10 power modules is developed to meet the requirements of copper-foil electrolysis. The power module is composed of a two-leg pulse width modulation (PWM) rectifier and a DC/DC converter. The DC/DC converter adopts two full-wave rectifiers in parallel to enhance the output. For the two-leg PWM rectifier, the ripple of the DC-link voltage is derived. A composite control method with a ripple filter is then proposed to effectively improve the performance of the rectifier. To meet the process demand of copper-foil electrolysis, the virtual impedance-based current-sharing control method with load current full feedforward is proposed for n-parallel DC/DC converters. The roles of load current feedforward and virtual impedance are analyzed, and the current-sharing control model of the HSPS system is derived. Virtual impedance is used to adjust the current-sharing impedance without changing the equivalent output impedance, which can effectively reduce current-sharing errors. Finally, simulation and experimental results verify the structure and control method.

Sulphonated Reduced Graphene Oxide: A High Performance Anode Material for Lithium Ion Battery

Haibo Li,Rui Niu,Sen Liang,Yulong Ma,Min Luo,Jin Li,Lijun He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.4

In this work, the sulfonated reduced graphene oxide (SRGO) was synthesized and proposed as an enhanced anode material for lithium ion battery (LIB). The result shows that the SRGO has an improved battery performance (i.e., ~341.7 mAh/g and ~190.6 mAh/g corresponds to SRGO and RGO at the 100th cycle with a current density of 200 mA/g) and superior cycling stability compared with pristine reduced graphene oxide (RGO). These are attributed to the improved specific surface area (448.35 m2 /g) and conductivity (2.5 x 10-4 S/m). Further, the SRGO exhibits good rate capability and excellent energy density at various current densities ranging from 50 mAh/g to 2000 mAh/g, suggesting that SRGO could be a promising anode material for high capacity LIB.

Autophagy induced by H. pylori VacA regulated the survival mechanism of the SGC7901 human gastric cancer cell line

Luo Juan,Bai Luyan,Tao Jun,Wen Yu,Li Mingke,Zhu Yunzhen,Luo Sufeng,Pu Guangyu,Ma Lanqing 한국유전학회 2021 Genes & Genomics Vol.43 No.10

Background Vacuolating cytotoxin (VacA) is an important virulence factor of Helicobacter pylori (H. pylori). It was previously believed that VacA can trigger the cascade of apoptosis on mitochondria to lead to cell apoptosis. Recently, it was found that VacA can induce autophagy. However, the molecular mechanism by which VacA induces autophagy is largely unknown. Objective We aimed to explore the molecular mechanism of autophagy induced by H. pylori in gastric cancer cells and the efect of autophagy on the survival of gastric cancer cells. Methods The autophagy of human gastric cancer cell line SGC7901 was detected by Western blot and RT-PCR in the treatment of VacA protein of H. pylori. The relationship between autophagy and reactive oxygen species (ROS) in the proliferation of gastric cancer cells were studied by gene expression silences (siRNA) and CM-H2DCFDA (DCF) staining. Results The results showed that VacA protein secreted by H. pylori in the supernatant stimulated autophagy in SGC7901 cells. After VacA protein treatment, the mRNA expressions of BECN1, ATG7 and PIK3C3, were up-regulated. ATG7 silencing by siRNA inhibited VacA-induced autophagy. Furthermore, our data demonstrated that VacA protein increased ROS levels. Addition of the antioxidant N-acetyl-l-cysteine (NAC) suppressed the levels of ROS, leading to inhibition of autophagy. Conclusions H. pylori VacA is a key toxin that induces autophagy by increased ROS levels. And our fndings demonstrated that VacA signifcantly inhibited proliferation in SGC7901 cells.

Percutaneous ablation of liver metastases from colorectal cancer: a comparison between the outcomes of ultrasound guidance and CT guidance using propensity score matching

Ma Luo,Sheng Peng,Guang Yang,Letao Lin,Ligong Lu,Jiawen Chen,Fujun Zhang,Fei Gao 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.1

Purpose: The aim of this study was to compare the effectiveness and outcomes of percutaneous ablation guided by ultrasonography (US) and computed tomography (CT) in colorectal liver oligometastases (CLOM). Methods: This study included patients with CLOM treated with percutaneous ablation from January 2008 to January 2021 in this observational study. Only lesions visualized on both CT and US images were further analyzed according to whether patients’ initial ablation treatments utilized US guidance or CT guidance. The Kaplan-Meier method was used to estimate local tumor progression (LTP)–free survival after propensity score matching (PSM). The LTP-free survival and treatment-related outcomes were compared between these two groups. Results: PSM identified 116 patients from each group, with 269 and 238 lesions in the USguided and CT-guided groups, respectively. US-guided ablation had a shorter average procedure time and lower cost than CT-guided ablation (27.54±12.06 minutes vs. 32.70±13.88 minutes, P=0.003; $2,175.13±618.17 vs. $2,455.49±710.25, P=0.002). For patients >60 years of age, the cumulative LTP rate at 1 year was lower in the US-guided group than in the CT-guided group (17.8% vs. 25.1%, P=0.038). For patients with perivascular liver lesions, the cumulative LTP rate at 1 year was lower in the US-guided group (14.4% vs. 28.2%, P=0.040). Conclusion: For patients whose age is >60 years or who have perivascular liver lesions, USguided ablation is better than CT-guided ablation, with a shorter treatment time and lower costs when both ablation methods are feasible for patients.

Improving Nutrient Use Efficiency and Yield of Canola in Eastern Canada

Bao-Luo Ma,D.l. Smith,J.l. Shang,J. Whalen,C. Caldwell,H. Earl,A. Vanasse,P. Scott 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Expression and Regulation of Transcription Factor FoxA2 in Chronic Rhinosinusitis With and Without Nasal Polyps

Qing Luo,Jia Zhang,Hongtian Wang,Fenghong Chen,Xi Luo,Beiping Miao,Xingmei Wu,Renqiang Ma,Xiangqian Luo,Geng Xu,Jianbo Shi,Huabin Li 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.5

Purpose: Chronic rhinosinusitis (CRS) is characterized by the excessive production of mucus. However, the molecular mechanism underlying mucin overproduction in CRS with or without nasal polyps (CRSwNP and CRSsNP, respectively) is poorly understood. This study was conducted to assess the importance of the transcription factor FoxA2 in mucin production and to investigate the targeting of FoxA2 as a potential therapeutic strategy for mucus hypersecretion in CRS patients. Methods: We enrolled 15 CRSwNP patients, 15 CRSsNP patients, and 10 normal controls in this study. The expression levels of FoxA2, MUC5AC, and MUC5B in inflamed and healthy nasal tissues were examined via immunohistochemistry and quantitative reverse transcription-polymerase chain reaction, and the levels of several proinflammatory cytokines in nasal secretions were measured via FlowCytomix analysis. In addition, the expression of MUC5AC and FoxA2 was determined in polyp-derived epithelial cells and NCI-H292 cells after in vitro stimulation. Results: FoxA2 was significantly down-regulated, and MUC5AC and MUC5B were significantly up-regulated in both the CRSwNP and CRSsNP patients compared to the controls (P<0.05), and the protein level of FoxA2 was negatively associated with the IL-6 level in the CRS patients (P<0.05). IL-6 significantly increased MUC5AC expression but inhibited FoxA2 expression in vitro (P<0.05). Transfection with a FoxA2 expression plasmid significantly decreased MUC5AC promoter activity (P<0.05) and inhibited IL-6-induced MUC5AC production (P<0.05). In addition, clarithromycin significantly alleviated IL-6-induced FoxA2 suppression and decreased MUC5AC expression in vitro (P<0.05). Conclusions: Our findings suggest that FoxA2 may be considered a therapeutic target for the modulation of mucus hypersecretion in CRS patients.

Manipulation of microdroplets at a T-junction: Coalescence and scaling law

Rui Ma,Qindan Zhang,Taotao Fu,Chunying Zhu,Kai Wang,Youguang Ma,Guangsheng Luo 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.65 No.-

The manipulation of a droplet at a microfluidic T-junction is achieved via adding reagents into the droplet with the same solution. Three types for droplet coalescence at the T-junction were observed: tail coalescence, slipping coalescence and unsteady coalescence behaviors with a new droplet formation. The final droplet size decreased (increased) with increasing the capillary number when the flow rate of the dispersed (continuous) phase was fixed. The final droplet size increased with increasing the capillary number of the added phase. The correlations for predicting the coalesced droplet size for tail and slipping coalescence were proposed.

The Power Analysis and Its Control of Two-phase Orthogonal Power Supply for the Continuous Casting

Ma, Fujun,Luo, An,Xiong, Qiaopo The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

In order to improve the quality of the billet continuous casting, a two-phase orthogonal power supply (TPOPS) for electromagnetic stirrer is researched, which is composed of three-phase PWM rectifier and three-leg inverter. According to the power analysis of system, the ripple of dc-link voltage is analyzed and its analytical expression is derived. In order to improve the performance of electromagnetic stirring, an integrated control method with feedforward control is proposed for PWM rectifier to suppress the fluctuations of dc-link voltage and provide a stable dc source for inverter. According to the simplified equivalent model, a composite current control method is proposed for inverter. This proposed method can combine the merits of feedforward control with feedback control to effectively improve the dynamic output performance of TPOPS. Finally, a 300kVA prototype of TPOPS is developed, and the results have verified the analysis and control method.

Affinity-Purification of Fibrinogenase with High Proteolytic Activity from Agkistrodon halys (Chinese) Venom

Ma, Biao,Zhan, Ying,Wu, Dan,Jia, Jianping,Xu, Wentao,Luo, Yunbo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

To purify and characterize the fibrinogenase with high proteolytic activity from Agkistrodon halys (Chinese) Venom. Monoclonal antibodies against fibrinogenase were prepared and a novel affinity chromatography equipped with a monoclonal antibody against fibrinogenase was developed and applied for the purification of fibrinogenases. The purified fibrinogenase was identified by fibrinolytic activity assay, and antithrombosis activity assay. HPLC chromatography and SDS-PAGE analysis demonstrated the uniformity and purity of the purified fibrinogenase. In comparison with a conventional A-50 chromatography method, affinity-purified fibrinogenase showed higher activity ($3631\;U\;mg^{-1}$ vs $501\;U\;mg^{-1}$). In addition, the physiological activity of the fibrinogenase both in vitro and ex vivo showed the purified fibrinogenase can specifically degrade $\beta$-, $\gamma$-fibrinogen and has a high anti-thrombotic activity. In conclusion, the purified fibrinogenase by affinity column were shown to be homogeneous and showed a high and specific proteolytic activity against $\beta$-chains of fibrinogen molecules and antithrombosis activity.

The Development of High-Current Power Supply System for Electrolytic Copper Foil

Luo, An,Ma, Fujun,Xiong, Qiaopo,He, Zhixing The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

A 6.5 V/50 kA high-frequency switching power supply (HSPS) system composed of 10 power modules is developed to meet the requirements of copper-foil electrolysis. The power module is composed of a two-leg pulse width modulation (PWM) rectifier and a DC/DC converter. The DC/DC converter adopts two full-wave rectifiers in parallel to enhance the output. For the two-leg PWM rectifier, the ripple of the DC-link voltage is derived. A composite control method with a ripple filter is then proposed to effectively improve the performance of the rectifier. To meet the process demand of copper-foil electrolysis, the virtual impedance-based current-sharing control method with load current full feedforward is proposed for n-parallel DC/DC converters. The roles of load current feedforward and virtual impedance are analyzed, and the current-sharing control model of the HSPS system is derived. Virtual impedance is used to adjust the current-sharing impedance without changing the equivalent output impedance, which can effectively reduce current-sharing errors. Finally, simulation and experimental results verify the structure and control method.