A New Direct Power Control Strategy for NPC Three-Level Voltage Source Rectifiers Using a Novel Vector Influence Table Method

Chang-Liang Xia,Zhe Xu,Jia-Xin Zhao 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper proposes a novel direct power control (DPC) strategy for neutral-point-clamped (NPC) three-level rectifiers, to directly control the active power, the reactive power and the neutral point potential of the rectifiers by referring to three pre-calculated vector influence tables and minimizing an objective function. In the three vector influence tables, the influences of different voltage vectors on the active power, the reactive power and the neutral-point potential are shown explicitly. A conceptual description and control algorithm of the proposed controller are presented in this paper. Then, numerical simulations and experiments are carried out to validate the proposed method. Both the simulation and experimental results show that good performances during both the steady-state and transient operating conditions are achieved. As a result, the proposed strategy has been proven to be effective for NPC three-level rectifiers.

A New Direct Power Control Strategy for NPC Three-Level Voltage Source Rectifiers Using a Novel Vector Influence Table Method

Xia, Chang-Liang,Xu, Zhe,Zhao, Jia-Xin The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper proposes a novel direct power control (DPC) strategy for neutral-point-clamped (NPC) three-level rectifiers, to directly control the active power, the reactive power and the neutral point potential of the rectifiers by referring to three pre-calculated vector influence tables and minimizing an objective function. In the three vector influence tables, the influences of different voltage vectors on the active power, the reactive power and the neutral-point potential are shown explicitly. A conceptual description and control algorithm of the proposed controller are presented in this paper. Then, numerical simulations and experiments are carried out to validate the proposed method. Both the simulation and experimental results show that good performances during both the steady-state and transient operating conditions are achieved. As a result, the proposed strategy has been proven to be effective for NPC three-level rectifiers.

CCR6 Is a Predicting Biomarker of Radiosensitivity and Potential Target of Radiosensitization in Rectal Cancer

Hui Chang,Jia-wang Wei,Ya-lan Tao,Pei-rong Ding,Yun-fei Xia,Yuan-hong Gao,Wei-wei Xiao 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Purpose This study aimed to explore the functions and mechanisms of C-C motif chemokine receptor 6 (CCR6), a gene associated with progression and metastasis of colorectal cancer (CRC), in radiosensitivity of rectal cancer (RC). Materials and Methods RNA sequencing and immunohistochemical analysis on CCR6 expression were performed in pretreatment tissues of RC patients exhibiting different therapeutic effects of radiotherapy. Colonogenic survival assay was conducted in different CRC cell lines to assess their radiosensitivity. And the impact of CCR6 expression on radiosensitivity was validated through RNA interference. The DNA damage repair (DDR) abilities of cell lines with different CCR6 expression were evaluated through immunofluorescence-based H2AX quantification. Results The CCR6 mRNA level was higher in patients without pathologic complete remission (pCR) than in those with pCR (fold changed, 2.11; p=0.004). High-level expression of CCR6 protein was more common in the bad responders than in the good responders (76.3% vs. 37.5%, p < 0.001). The CRC cell lines with higher CCR6 expression (LoVo and sw480) appeared to be more radioresistant, compared with the sw620 cell line which had lower CCR6 expression. CCR6 knockdown made the LoVo cells more sensitive to ionizing radiation (sensitization enhancement ratio, 1.738; p < 0.001), and decreased their DDR efficiency. Conclusion CCR6 might affect the RC radiosensitivity through DDR process. These findings supported CCR6 as a predicting biomarker of radiosensitivity and a potential target of radiosensitization for RC patients.

Synthesis and Antibacterial Evaluation of (S,Z)-4-methyl-2-(4-oxo-5-((5-substituted phenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)Pentanoic Acids

Song, Ming-Xia,Deng, Xian-Qing,Wei, Zhi-Yu,Zheng, Chang-Ji,Wu, Yan,An, Chang-Shan,Piao, Hu-Ri Shaheed Beheshti University of Medical Sciences 2015 Iranian journal of pharmaceutical research Vol.14 No.1

<P>The microbial resistance has become a global hazard with the irrational use of antibiotics. Infection of drug-resistant bacteria seriously threatens human health. Currently, there is an urgent need for the development of novel antimicrobial agents with new mechanisms and lower levels of toxicity. In this paper, a series of (<I>S</I><I>,Z</I>)-4-methyl-2-(4-oxo-5-((5-substitutedphenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)pentanoic acids via a Knoevenagel condensation were synthesized and evaluated for their antibacterial activity <I>in</I><I>-</I><I>vitro</I>. The synthesized compounds were characterized by IR, <SUP>1</SUP>H NMR and MS. The antibacterial test<I> in</I><I>-</I><I>vitro</I> showed that all of the synthesized compounds had good antibacterial activity against several Gram-positive bacteria (including multidrug-resistant clinical isolates) with minimum inhibitory concentration (MIC) values in the range of 2–4 µg/mL. Especially compounds 4c, 4d, 4e and 4f were the most potent, with MIC values of 2 µg/mL against four multidrug-resistant Gram-positive bacterial strains.</P>

ppGalNAc T1 as a Potential Novel Marker for Human Bladder Cancer

Ding, Ming-Xia,Wang, Hai-Feng,Wang, Jian-Song,Zhan, Hui,Zuo, Yi-Gang,Yang, De-Lin,Liu, Jing-Yu,Wang, Wei,Ke, Chang-Xing,Yan, Ru-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAc T1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells in vitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9) expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell line with well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigate changes of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessed using [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumors in BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diameters of tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA in bladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expression in EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reduced incorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the empty vector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration (only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth compared with the control groups injected with empty vector transfected control cells. At the end of observation course (40 days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAc T1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused no remarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growth of the bladder cancer EJ cell line.

Arrays of Sealed Silicon Nanotubes As Anodes for Lithium Ion Batteries

Song, Taeseup,Xia, Jianliang,Lee, Jin-Hyon,Lee, Dong Hyun,Kwon, Moon-Seok,Choi, Jae-Man,Wu, Jian,Doo, Seok Kwang,Chang, Hyuk,Park, Won Il,Zang, Dong Sik,Kim, Hansu,Huang, Yonggang,Hwang, Keh-Chih,Roge American Chemical Society 2010 NANO LETTERS Vol.10 No.5

<P>Silicon is a promising candidate for electrodes in lithium ion batteries due to its large theoretical energy density. Poor capacity retention, caused by pulverization of Si during cycling, frustrates its practical application. We have developed a nanostructured form of silicon, consisting of arrays of sealed, tubular geometries that is capable of accommodating large volume changes associated with lithiation in battery applications. Such electrodes exhibit high initial Coulombic efficiencies (i.e., >85%) and stable capacity-retention (>80% after 50 cycles), due to an unusual, underlying mechanics that is dominated by free surfaces. This physics is manifested by a strongly anisotropic expansion in which 400% volumetric increases are accomplished with only relatively small (<35%) changes in the axial dimension. These experimental results and associated theoretical mechanics models demonstrate the extent to which nanoscale engineering of electrode geometry can be used to advantage in the design of rechargeable batteries with highly reversible capacity and long-term cycle stability.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2010/nalefd.2010.10.issue-5/nl100086e/production/images/medium/nl-2010-00086e_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl100086e'>ACS Electronic Supporting Info</A></P>

A nonNMDA antagonist, GYKI 52466 improves microscopic O₂balance in the cortex during focal cerebral ischemia

Chi, Oak Z.,Chang, Qiang,Wang, Guolin,Liu, Xia,Harvey R. Weiss 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Oak Z.Chi,Qiang Chang, Guolin Wang*, Xia Liu, Harvey R. Weiss□.Deprtments of Anesthesai, Departments of Physiology and Biophysics, University of Medicne and Dentisrty of New Jersey,Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA and*Department of Anesthesia, Medical University, Tianjing, People's Republic of China. A non-NMDA antagonist, GYKI 52466 improves microscopic O² balance in the cortex during focal cerebral ischemia. Proceedings of International Symposium on East-West Medicine, Seoul. 172-182, 1999.-This study was performed to test whether GYKI 52466, a non-NMDA receptor antagonist, would improve microregional oxygen supply and consumption balance in the focal cerebral ischemic area. Rats were anesthetized with 1.4% isoflurance. For the GYKI Group (n=8), 19 min before middle cerebral artery (MCA) occlusion, a bolus of 5mg/kg of GYKI 52466 iv was administered and was followed by an infusion of 5mg/kg/hr. For the control Group(n=8), the same volume of the vehicle was administered. One hour after MCA occlusion, regional cerebral blood flow (rCBF) was measured using the 14C-iodoantipyrine autoradiographic technique. Microscopic arterial and venous oxygen saturations were determined using microspectrophotometry. In the cortex contralateral to MCA occlusion, the average rCBF and the average O² consumption were lower in the GYKI Group than in the Control Group (rCBF:GYKI 65.5±24.1, Control 97.7 33.4ml/100g/min;O² consumption: GYKI3.9±1.2, Control 6.2±2.5ml O²/100g/min) without a significant difference in the number of veins with SvO²<50%. In the ischemic cortex, the number of veins with SvO²<50% was significantly smaller in the GYKI Group (21 veins out of 63)than in the Control Group(45 out of 59)without a significant difference in the average rCBF(GYKI44.9±17.7, Control 29.7±10.4) or regional O² consumption between these two groups (GYKI 3.3±1.4,Control 27.7±1.2). Our data demonstrated that GYKI 52466 was effective in improving microscopic O² balance in the focal ischemic cortical area of the brain and it decreased O² consumption in the non-ischemic cortex. [Neurological Research 1999;21:299-304]

The Feasibility of Using Biomarkers Derived from Circulating Tumor DNA Sequencing as Predictive Classifiers in Patients with Small-Cell Lung Cancer

Yu Feng,Yutao Liu,Mingming Yuan,Guilan Dong,Hongxia Zhang,Tongmei Zhang,Lianpeng Chang,Xuefeng Xia,Lifeng Li,Haohua Zhu,Puyuan Xing,Hongyu Wang,Yuankai Shi,Zhijie Wang,Xingsheng Hu 대한암학회 2022 Cancer Research and Treatment Vol.54 No.3

Purpose To investigate the feasibility of biomarkers based on dynamic circulating tumor DNA (ctDNA) to classify small cell lung cancer (SCLC) into different subtypes. Materials and Methods Tumor and longitudinal plasma ctDNA samples were analyzed by next-generation sequencing of 1,021 genes. PyClone was used to infer the molecular tumor burden index (mTBI). Pre-treatment tumor tissues [T1] and serial plasma samples were collected (pre-treatment [B1], after two [B2], six [B3] cycles of chemotherapy and at progression [B4]). Results Overall concordance between T1 and B1 sequencing (n=30) was 66.5%, and 89.5% in the gene of <i>RB1</i>. A classification method was designed according to the changes of <i>RB1</i> mutation, named as subtype Ⅰ (both positive at B1 and B2), subtype Ⅱ (positive at B1 but negative at B2), and subtype Ⅲ (both negative at B1 and B2). The median progressive-free survival for subtype Ⅰ patients (4.5 months [95%CI: 2.6-5.8]) was inferior to subtype Ⅱ (not reached, p<0.0001) and subtype Ⅲ (10.8 months [95%CI: 6.0-14.4], p=0.002). The median overall survival for subtype Ⅰ patients (16.3 months [95%CI: 5.3-22.9]) was inferior to subtype Ⅱ (not reached, p=0.01) and subtype Ⅲ (not reached, p=0.02). Patients with a mTBI dropped to zero at B2 had longer median overall survival (not reached vs. 19.5 months, p=0.01). The changes of mTBI from B4 to B1 were sensitive to predict new metastases, with a sensitivity of 100% and a specificity of 85.7%. Conclusion Monitoring ctDNA based <i>RB1</i> mutation and mTBI provided a feasible tool to predict the prognosis of SCLC.

A Novel Subregion-Based Multidimensional Optimization of Electromagnetic Devices Assisted by Kriging Surrogate Model

Xia, Bin,Ren, Ziyan,Choi, Kyung,Koh, Chang-Seop IEEE 2017 IEEE transactions on magnetics Vol.53 No.6

<P>A novel subregion-based optimization strategy utilizing an adaptive dynamic Taylor Kriging (ADTK) surrogate model is developed for a multidimensional optimal design of electromagnetic devices. In the algorithm, the whole design space is divided into a series of subregion, which has its own local ADTK model with optimal set of basis functions. For all subregions, a global optimal solution is found by using particle swarm optimization with the help of the local ADTK models of the objective and constraint functions. The proposed algorithm improves remarkably the accuracy of the ADTK model by reducing the computational complexity. It also significantly reduces the computational cost especially for an optimal design of large-scale multidimensional problems. Finally, the effectiveness of the proposed method is demonstrated through applications to two benchmark problems: TEAM problems 22 and 25.</P>

A Novel Reliability-Based Optimal Design of Electromagnetic Devices Based on Adaptive Dynamic Taylor Kriging

Xia, Bin,Ren, Ziyan,Koh, Chang Seop IEEE 2017 IEEE transactions on magnetics Vol.53 No.6

<P>This paper proposes an efficient reliability-based optimization algorithm based on adaptive dynamic Taylor Kriging (ADTK). In the ADTK model, the basis functions are optimally selected by the binary particle swarm optimization algorithm and the minimal number of sampling data with a desired fitting error is decided. To evaluate performance of reliability calculation, the Monte Carlo simulation method is employed, where the performance constraint functions are constructed by the ADTK surrogate model. Overall, an electromagnetic application-superconducting magnetic energy storage device (TEAM problem 22) is used to investigate performances of the proposed method.</P>