A Single-phase Buck-boost AC-AC Converter with Three Legs

Zhou, Min,Sun, Yao,Su, Mei,Li, Xing,Liu, Fulin,Liu, Yonglu The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

This paper proposes a single-phase buck-boost AC-AC converter. It consists of three legs with six switching units (each unit is composed of an active switch and a diode) and its input and output ports share a common ground. It can provide buck-boost voltage operation and immune from shoot-through problem. Since only two switching units are involved in the current paths, the conduction losses are low, which improves the system efficiency. The operation principle of the proposed circuit is firstly presented, and then, various operation conditions are introduced to achieve different output voltages with step-changed frequencies. Additionally, the parameters design and comparative analysis of the power losses are also given. Finally, experimental results verify the correctness of the proposed converter.

A Single-phase Buck-boost AC-AC Converter with Three Legs

Min Zhou,Yao Sun,Mei Su,Xing Li,Fulin Liu,Yonglu Liu 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

This paper proposes a single-phase buck-boost AC-AC converter. It consists of three legs with six switching units (each unit is composed of an active switch and a diode) and its input and output ports share a common ground. It can provide buck-boost voltage operation and immune from shoot-through problem. Since only two switching units are involved in the current paths, the conduction losses are low, which improves the system efficiency. The operation principle of the proposed circuit is firstly presented, and then, various operation conditions are introduced to achieve different output voltages with step-changed frequencies. Additionally, the parameters design and comparative analysis of the power losses are also given. Finally, experimental results verify the correctness of the proposed converter.

High-efficiency degradation of quinclorac via peroxymonosulfate activated by N-doped CoFe2O4/Fe0@CEDTA hybrid catalyst

Lezhu Su,Lizhou Ou,Yujiao Wen,Yifan Wang,Weilin Zhao,Zhi Zhou,Mei-e Zhong,YONGFA ZHU,Nan Zhou 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.102 No.-

Exploring catalyst materials which are advancing, recyclable and with high catalytic performances toremove persistent organic pollutants such as Quinclorac (QNC) is important. In this work, a novel Ndopedcarbon support CoFe2O4/Fe0 hybrid catalyst (CFO/Fe@C) was in situ formed by a simple coprecipitationand calcination process. Fine intergrowth crystal CoFe2O4 and Fe0 were uniformly dispersedon the N-doped porous carbon that derived from the raw material Ethylene Diamine Tetraacetic Acid(EDTA), which also provided chelating effect to prevent the agglomeration of the metals. Interestingly,the Fe0 could only be formed with the presence of cobalt, possibly due to the increased reduction propertyresulted from the particle refinement. The as-formed Fe0 could not only activate the peroxymonosulfate(PMS) but also reduce the Co3+, resulting in a synergistic impact to remarkably enhance thedegradation performance. Besides, the N-doped porous carbon can also benefit the degradation of pollutantby strengthening the electron transfer. A good degradation efficiency of QNC was obtained in CFO/Fe@C-PMS system and most of the QNC had been degraded to carbon dioxide, water and other smallmolecular organisms. The removal rate remained over 70% after four reuses and the material could beeasily recovered from the solution due to the good magnetic properties. Therefore, the as-preparedCFO/Fe@C catalyst should be an ideal catalyst for the removal of organic pollutants.

MAGED4 Expression in Glioma and Upregulation in Glioma Cell Lines with 5-Aza-2'-Deoxycytidine Treatment

Zhang, Qing-Mei,Shen, Ning,Xie, Sha,Bi, Shui-Qing,Luo, Bin,Lin, Yong-Da,Fu, Jun,Zhou, Su-Fang,Luo, Guo-Rong,Xie, Xiao-Xun,Xiao, Shao-Wen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Melanoma-associated antigen (MAGE) family genes have been considered as potentially promising targets for anticancer immunotherapy. MAGED4 was originally identified as a glioma-specific antigen. Current knowledge about MAGED4 expression in glioma is only based on mRNA analysis and MAGED4 protein expression has not been elucidated. In the present study, we investigated this point and found that MAGED4 mRNA and protein were absent or very lowly expressed in various normal tissues and glioma cell line SHG44, but overexpressed in glioma cell lines A172,U251,U87-MG as well as glioma tissues, with significant heterogeneity. Furthermore, MAGED4 protein expression was positively correlated with the glioma type and grade. We also found that the expression of MAGED4 inversely correlated with the overall methylation status of the MAGED4 promoter CpG island. Furthermore, when SHG44 and A172 with higher methylation were treated with the DNA demethylating agent 5-aza-2'-deoxycytidine (5-AZA-CdR) reactivation of MAGED4 mRNA was mediated by significant demethylation in SHG44 instead of A172. However, 5-AZA-CdR treatment had no effect on MAGED4 protein in both SHG44 and A172 cells. In conclusion, MAGED4 is frequently and highly expressed in glioma and is partly regulated by DNA methylation. The results suggest that MAGED4 might be a promising target for glioma immunotherapy combined with 5-AZA-CdR to enhance its expression and eliminate intratumor heterogeneity.

Relationship Between Computed Tomography Manifestations of Thymic Epithelial Tumors and the WHO Pathological Classification

Liu, Guo-Bing,Qu, Yan-Juan,Liao, Mei-Yan,Hu, Hui-Juan,Yang, Gui-Fang,Zhou, Su-Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Objective: To explore the relationship between computed tomography (CT) manifestations of thymoma and its WHO pathological classification. Methods: One hundred and five histopathologically confirmed cases were collected for their pathological and CT characteristics and results were statistically compared between different pathological types of thymoma. Results: Tumor size, shape, necrosis or cystic change, capsule integrity, invasion to the adjacent tissue, lymphadenopathy, and the presence of pleural effusion were significantly different between different pathological types of thymomas (P<0.05). Type B2, B3 tumors and thymic carcinomas were greater in size than other types. More than 50% of type B3 tumors and thymic carcinomas had a tumor size greater than 10 cm. The shape of types A, AB, and B1 tumors were mostly round or oval, whereas 75% of type B3 tumors and 85% of thymic carcinomas were irregular in shape. Necrosis or cystic change occurred in 67% of type B3 thymomas and 57% of thymic carcinomas, respectively. The respective figures for capsule destruction were 83% and 100%. Increases in the degree of malignancy were associated with increases in the incidence of surrounding tissue invasion: 33%, 75%, and 81% in type B2, type B3, and thymic carcinomas, respectively. Pleural effusion occurred in 48% of thymic carcinomas, while calcification was observed mostly in type B thymomas. Conclusions: Different pathological types of thymic epithelial tumors have different CT manifestations. Distinctive CT features of thymomas may reflect their pathological types.

Rapid functional screening of effective siRNAs against Plk1 and its growth inhibitory effects in Laryngeal carcinoma cells

( Huan Lan ),( Jiang Zhu ),( Qing Ai ),( Zheng Mei Yang ),( Ying Ji ),( Su Ling Hong ),( Fang Zhou Song ),( You Quan Bu ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.12

Plk 1 is overexpressed in many human malignancies including laryngeal carcinoma. However, its therapeutic potential has been never examined in laryngeal carcinoma. In the present study, a simple cellular morphology-based strategy was firstly proposed for rapidly screening the effective siRNAs against Plk1. Furthermore, we investigated the effects of Plk1 depletion via a novel identified effective siRNA against Plk1, Plk1 siRNA-607, on human laryngeal carcinoma Hep-2 cells. The results indicated that Plk1 siRNA-607 transfection resulted in a significant inhibition in Plk1 expression in cells, and subsequently caused a dramatic mitotic cell cycle arrest followed by massive apoptotic cell death, and eventually resulted in a significant decrease in growth and viability of the laryngeal carcinoma cells. Taken together, our present study not only suggests a simple strategy for rapidly screening effective siRNAs against Plk1 but also implicates that Plk1 may serve as a potential therapeutic target in human laryngeal carcinoma. [BMB reports 2010; 43(12): 818-823]

KLF4 Expression Correlates with the Degree of Differentiation in Colorectal Cancer

( Ruo Lei Hu ),( Yan Zuo ),( Li Zuo ),( Chao Liu ),( Su Mei Zhang ),( Qiang Wu ),( Qing Zhou ),( Shu Yu Gui ),( Wei Wei ),( Yuan Wang ) 대한소화기기능성질환·운동학회 2011 Gut and Liver Vol.5 No.2

Background/Aims: Kruppel-like factor 4 (KLF4) is an epithelial-specifi c transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer. Methods: We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed. Results: The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p<0.05) when compared to normal appearing mucosa. The negative and weak positive staining rates in normal appearing mucosa, adenoma, and carcinoma were 42.5%, 71.4%, and 82.3%, respectively, indicating a decreased degree of KLF4 expression over the course of progressive transformation of normal cells into malignant derivatives. KLF4 protein levels showed no correlation with sex, age, or metastatic state (p>0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression signifi cantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation. Conclusions: Downregulation of KLF4 expression may lead to more poorly differentiated tumors. (Gut Liver 2011;5:154-159)

Melatonin inhibits the Migration of Colon Cancer RKO cells by Down-regulating Myosin Light Chain Kinase Expression through Cross-talk with p38 MAPK

Zou, Duo-Bing,Wei, Xiao,Hu, Ruo-Lei,Yang, Xiao-Ping,Zuo, Li,Zhang, Su-Mei,Zhu, Hua-Qing,Zhou, Qing,Gui, Shu-Yu,Wang, Yuan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.14

Background: Melatonin, which is mainly produced by the pineal gland, has a good inhibitory effect on cell growth of multiple cancer types. However, the underlying molecular mechanisms of anti-tumor activity for colon cancer have not been fully elucidated. In this study, we investigated the effects of melatonin on migration in human colon cancer RKO cells and the potential molecular mechanisms. Materials and Methods: The viability of RKO cells was investigated by MTT assay after treatment with melatonin, SB203580 (p38 inhibitor) and phorbol 12-myristate 13-acetate (PMA, MAPK activator) alone or in combination for 48h. The effects of melatonin, and ML-7, a selective inhibitor of myosin light chain kinase (MLCK), and SB203580, and PMA on the migration of RKO cells were analyzed by in vitro scratch-wound assay. The relative mRNA levels of MLCK was assessed by real-time quantitative RT-PCR. Western blotting analysis was performed to examine the expression of MLCK, phosphorylation of myosin light chain (pMLC) and p38 (pp38). Results: The proliferation and migration of human colon cancer RKO cells were inhibited significantly after treatment with melatonin. The expression levels of MLCK and phosphorylation of MLC of RKO cells were reduced, and real-time quantitative RT-PCR showed that melatonin had significant effects on suppressing the expression of MLCK. Furthermore, the phosphorylation level of p38, which showed the same trend, was also reduced when cells were treated by melatonin. In addition, ML-7 (25umol/l) could down-regulate the phosphorylation of p38. Conclusions: Melatonin could inhibit the proliferation and migration of RKO cells, and further experiments confirmed that p38 MAPK plays an important role in regulating melatonin-induced migration inhibition through down-regulating the expression and activity of MLCK.

Quality improvement effects of electrolyzed water on rice noodles prepared with semidry-milled rice flours

Rui Liu,Zhang-Long Yu,Yuan-Lin Sun,Li-Tao Tong,Li-Ya Liu,Li-Li Wang,Xian-Rong Zhou,Su-Mei Zhou 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.6

To investigate the effects of electrolyzed watertreatment on the qualities of rice noodles prepared withsemidry- milled rice flour, pasting properties and thermalproperties of rice flour, and the cooking and texturalproperties of rice noodles were determined. Higher peakviscosity and lower melting enthalpy were observed inelectrolyzed water (EW) treated rice flour. The hardness,gumminess and chewiness of rice noodle in slightly acidicelectrolyzed water treated rice noodles with availablechlorine concentration (ACC) 20.32 mg/L were increasedsignificantly (p\0.05). The cooking loss decreased significantlyin strong acidic electrolyzed water treated noodleswith ACC 10.09 mg/L treatment (p\0.05). Theresults indicated that EW could promote the gelatinizationof rice flour, and improve the textural qualities of ricenoodles. Therefore EW was appropriate to be used in ricenoodle production.