An Improved Active Damping Method with Capacitor Current Feedback

Yi-Wen Geng,Ya-Wen Qi,Hai-Wei Liu,Fei Guo,Peng-Fei Zheng,Yong-Gang Li,Wen-Ming Dong 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, fs/6). However, the resonance frequency (fr) of an LCL-type filter is usually designed to be less than half the sampling frequency (fs) with the symmetry regular sampling method. Therefore, (fs/6, fs/2) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, fs/6) to (0, fs/2), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, fs/2). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain Kp. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.

An Improved Active Damping Method with Capacitor Current Feedback

Geng, Yi-Wen,Qi, Ya-Wen,Liu, Hai-Wei,Guo, Fei,Zheng, Peng-Fei,Li, Yong-Gang,Dong, Wen-Ming The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, $f_s/6$. However, the resonance frequency ($f_r$) of an LCL-type filter is usually designed to be less than half the sampling frequency ($f_s$) with the symmetry regular sampling method. Therefore, ($f_s/6$, $f_s/2$) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, $f_s/6$ to (0, $f_s/2$), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, $f_s/2$). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain $K_p$. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.

Protective association of Klotho rs495392 gene polymorphism against hepatic steatosis in non-alcoholic fatty liver disease patients

Wen-Yue Liu,Xiaofang Zhang,Gang Li,Liang-Jie Tang,Pei-Wu Zhu,Rafael S. Rios,Kenneth I. Zheng,Hong-Lei Ma,Xiao-Dong Wang,Qiuwei Pan,Robert J. de Knegt,Luca Valenti,Mohsen Ghanbari,Ming-Hua Zheng 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.2

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic dysfunction. Among the multiple factors, genetic variation acts as important modifiers. Klotho, an enzyme encoded by the klotho (KL) gene in human, has been implicated in the pathogenesis of metabolic dysfunctions. However, the impact of variants in KL on NAFLD risk remains poorly understood. The aim of this study was to investigate the impact of KL rs495392 C>A polymorphism on the histological severity of NAFLD. Methods: We evaluated the impact of the KL rs495392 polymorphism on liver histology in 531 Chinese with NAFLD and replicated that in the population-based Rotterdam Study cohort. The interactions between the rs495392, vitamin D, and patatin-like phospholipase domain containing 3 (PNPLA3) rs738409 polymorphism were also analyzed. Results: Carriage of the rs495392 A allele had a protective effect on steatosis severity (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.42–0.89; P=0.010) in Chinese patients. After adjustment for potential confounders, the A allele remained significant with a protective effect (OR, 0.66; 95% CI, 0.45–0.98; P=0.040). The effect on hepatic steatosis was confirmed in the Rotterdam Study cohort. Additional analysis showed the association between serum vitamin D levels and NAFLD specifically in rs495392 A allele carriers, but not in non-carriers. Moreover, we found that the rs495392 A allele attenuated the detrimental impact of PNPLA3 rs738409 G allele on the risk of severe hepatic steatosis. Conclusions: The KL rs495392 polymorphism has a protective effect against hepatic steatosis in patients with NAFLD.

Modification of DC Flashover Voltage at High Altitude on the Basis of Molecular Gas Dynamics

Dong-Ming Liu,Fu-Sheng Guo,Wen-xia Sima 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.2

The effect of altitude on thermal conduction, surface temperature, and thermal radiation of partial arc was investigated on the basis of molecular gas dynamics to facilitate a deep understanding of the pollution surface discharge mechanism. The DC flashover model was consequently modified at high altitude. The validity of the modified DC flashover model proposed in this paper was proven through a comparison with the results of high-altitude simulation experiments and earlier models. Moreover, the modified model was found to be better than the earlier modified models in terms of forecasting the flashover voltage. Findings indicated that both the thermal conduction coefficient and the surface thermodynamics temperature of partial arc had a linear decrease tendency with the altitude increasing from 0 m to 3000 m, both of which dropped by approximately 30% and 3.6%, respectively. Meanwhile, the heat conduction and the heat radiation of partial arc both had a similar linear decrease of approximately 15%. The maximum error of DC pollution flashover voltage between the calculation value according to the modified model and the experimental value was within 6.6%, and the pollution flashover voltage exhibited a parabola downtrend with increasing of pollution.

Crop Production and Environment friendly-agriculture in China

Ming Zhao,Lifeng Fang,Zhiqiang Dong,Xianguo Zhu,Wen Jiang 한국작물학회 2005 한국작물학회 학술발표대회 논문집 Vol.2005 No.-

Apoptosis of Human Burkitt’s Lymphoma Cells Induced by 2-N,NDiethylaminocarbonyloxymethyl-1-diphenylmethyl-4-(3,4,5-trimethoxybenzoyl) piperazine Hydrochloride (PMS-1077)

Wen-di Wang,Xi-ming Xu,Ying Chen,Peng Jiang,Chang-zhi Dong,Qin Wang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12

Piperazine is one of the heterocycles which are associated with diverse pharmacological activities. 2-N,N-Diethylaminocarbonyloxymethyl-1-diphenylmethyl-4-(3,4,5-trimethoxybenzoyl) piperazine hydrochloride (PMS-1077) is a trisubstituted piperazine which contains a trimethoxybenzene ring and a benzhydrylpiperazine fragment, both of which can induce cell proliferation regression by different mechanisms. We have therefore examined the effects of PMS-1077 on Human Burkitt’s lymphoma cells (Raji). The viability of Raji cells was determined by MTT assay and also assessed by trypan blue dye exclusion method. The results demonstrate that PMS-1077 can suppress the proliferation of Raji cells in a dose- and timedependent manner, while inhibit colony formation ability of Raji cells merely in a dose-dependent manner in vitro. Meanwhile, morphological changes were observed using fluorescence microscope. Flow cytometric analysis through PI stains showed that PMS-1077 blocked the growth of Raji cells in the G0/G1 period, and induced apoptosis of Raji cells after 48 h of incubation. Cell apoptosis induced by PMS-1077 was further confirmed by staining with Annexin-V FITC and PI. Preliminary study by molecular docking suggests that PMS-1077 may inhibit tubulin polymerization. More experiments are in progress in our laboratory to reveal the mode of action of PMS-1077 in the induction of apoptosis of Raji cells.

Glycididazole Sodium Combined with Radiochemotherapy for Locally Advanced Nasopharyngeal Carcinoma

Li, Ming-Yi,Liu, Jin-Quan,Chen, Dong-Ping,Qi, Bin,Liang, Yu-Ying,Yin, Wen-Jing Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: To evaluate efficacy and side effects of glycididazole sodium (CMNa) combined with chemotherapy (cisplatin plus 5-FU/folic acid, PLF) and radiotherapy in treating patients with locally advanced nasopharyngeal carcinoma. Materials and Methods: Patients with III~IV stage nasopharyngeal carcinoma (NPC),were randomly divided into treatment group (46 patients) and control group (45 patients). Both groups received radiotherapy concomitant with PLF chemotherapy. The treatment group at the same time cwas given CMNa ($800mg/m^2$ before radiotherapy), by l h intravenous drip, three times a week. Results: When the dose of radiation was over 60 Gy, complete response rates of nasopharyngeal tumor and lymph node metastases in treatment group were significantly higher than in the control group (93.5% vs 77.8%; 89.1% vs 93.5%, p<0.05). Three months after radiotherapy, complete response rate of nasopharynx cancer and lymph node metastases in treatment group was both 97.8%, again higher than in the control group (84.4% and 82.2%) (p<0.05). In the treatment group, 1, 3, 5 year disease-free survival rates were 95.7%, 86.7% and 54.5%; and in control group, the corresponding disease-free survival rates were 93.3%, 66.2% and 38.6%, respectively, the difference being statistically significant (log-rank =5.887, p=0.015). One, 3, 5 year overall survival rates in two groups of patients were 97.8%, 93.5%, 70.4% and 95.5%, 88.07%, 48.4%, respectively, again with a statistically significant difference (log-rank=6.470, p=0.011). Acute toxicity and long-term radiotherapy related toxicity in the two groups did not differ (p>0.05). Conclusions: Glycididazole sodium could improve curative effects without increasing adverse reactions when treating paitents with locally advanced nasopharyngeal carcinoma.

Purification and Characterization of Cathepsin B from the Gut of the Sea Cucumber (Stichopus japonicas)

Li-Ming Sun,Bei-Wei Zhu,Hai-tao Wu,Lei Yu,Da-Yong Zhou,Xiuping Dong,Jing-Feng Yang,Dong-Mei Li,Wen-Xiu Ye,Yoshiyuki Murata 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.4

Cathepsin B from the gut of sea cucumber (Stichopus japonicas) was purified 81-fold with a 3%recovery by ammonium sulfate fractionation and a series chromatography on DEAE Sepharose CL-6B, Sephadex G-75, and TSK-Gel 3000 SWxl. The purified protein appeared as a single band on Native-PAGE but showed 2bands of 23 and 26 kDa on SDS-PAGE. The optimum activity was found at pH 5.5 and 45°C. The enzyme was stable at pH 4.5-6.0 and the thermal stability was up to 50oC. The enzyme was strongly inhibited by E-64, iodoacetic acid, and antipain, demonstrating it is a cysteine protease containing sulfhydryl groups. Cu^2+, Ni^2+, and Zn^2+ could strongly inhibit the enzyme activity. The amino acid sequences of the purified enzyme were acquired by mass spectrometer, which did not show any homology with previously described cathepsins, suggesting it may be a novel member.

MiR-221 promotes trastuzumab-resistance and metastasis in HER2-positive breast cancers by targeting PTEN?

( Xing Ming Ye ),( Wen Dong Bai ),( Hua Yu Zhu ),( Xiao Zhang ),( Ying Chen ),( Lei Wang ),( An Gang Yang ),( Jing Zh Ao ),( Lin Tao Jia ) 생화학분자생물학회 2014 BMB Reports Vol.47 No.5

HER2-overexpressing breast cancers are characterized byfrequent distant metastasis and often develop resistance aftershort-term effective treatment with the monoclonal antibodydrug, trastuzumab. Here, we found that the oncogenic miRNA,miR-221, inhibited apoptosis, induced trastuzumab resistanceand promoted metastasis of HER2-positive breast cancers. Thetumor suppressor PTEN was identified as a miR-221 target;overexpression of PTEN abrogated the aforementionedmiR-221-induced malignant phenotypes of the cells. Thesefindings indicate that miR-221 may promote trastuzumabresistance and metastasis of HER2-positive breast cancers bytargeting PTEN, suggesting its role as a potential biomarker forprogression and poor prognosis, and as a novel target fortrastuzumab-combined treatment of breast cancers.[BMB Reports 2014; 47(5): 268-273]

Beryllium oxide utilized in nuclear reactors: Part I: Application history, thermal properties, mechanical properties, corrosion behavior and fabrication methods

Hou Ming-dong,Zhou Xiang-wen,Liu Bing 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.12

In recent years, beryllium oxide has been widely utilized in multiple compact nuclear reactors as the neutron moderator, the neutron reflector or the matrix material with dispersed nuclear fuels due to its prominent properties. In the past 70 years, beryllium oxide has been studied extensively, but rarely been systematically organized. This article provides a systematic review of the application history, thermal properties, mechanical properties, corrosion behavior and fabrication methods of beryllium oxide. Data from previous literature are extracted and sorted out, and all of these original data are attached as the supplementary material, so that subsequent researchers can utilize this paper as a database for beryllium oxide research in reactor design or simulation analysis, etc. In addition, this review article also attempts to point out the insufficiency of research on beryllium oxide, and the possible key research areas about beryllium oxide in the future.