A Parallel Power Quality Conditioner without Harmonic Detection

Yan-jun Zhang,Zhen YANG,Sheng-fei YANG,Rong ZHANG 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A non-harmonic detection Parallel Power Quality Conditioner (PPQC) which can compensate harmonics and reactive power without harmonic and reactive power detection is introduced. By studying the energy exchange process and principle between the AC side and DC side, a DC voltage control method, controlling the magnitude and direction of the current flowing into the DC side, is proposed, to keep the DC voltage stable. The influence of the load active current on the DC voltage is analyzed in detail. A new non- harmonic detection control strategy is proposed with the load active current as a perturbation. The proposed control strategy which avoids complex detection algorithm, and in turn the errors and delay caused by detection algorithm, improves dynamic response speed greatly. Experiment results exhibit excellent harmonic and reactive power compensation performance and dynamic response.

Production and Characterization of Ethanol- and Protease-Tolerant and Xylooligosaccharides-Producing Endoxylanase from Humicola sp Ly01

( Jun Pei Zhou ),( Qian Wu ),( Rui Zhang ),( Yu Ying Yang ),( Xiang Hua Tang ),( Jun Jun Li ),( Jun Mei Ding ),( Yan Yan Dong ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% KH2PO4, and 0.5% peptone; initial pH 7.0; incubation time 72 h; 30℃; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at 60℃ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at 30℃ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 μmol/ml reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

Increased Serotonin Signaling Contributes to the Warburg Effect in Pancreatic Tumor Cells Under Metabolic Stress and Promotes Growth of Pancreatic Tumors in Mice

Jiang, Shu-Heng,Li, Jun,Dong, Fang-Yuan,Yang, Jian-Yu,Liu, De-Jun,Yang, Xiao-Mei,Wang, Ya-Hui,Yang, Min-Wei,Fu, Xue-Liang,Zhang, Xiao-Xin,Li, Qing,Pang, Xiu-Feng,Huo, Yan-Miao,Li, Jiao,Zhang, Jun-Feng Elsevier 2017 Gastroenterology Vol.153 No.1

<P><B>Background & Aims</B></P> <P>Desmoplasia and poor vascularity cause severe metabolic stress in pancreatic ductal adenocarcinomas (PDACs). Serotonin (5-HT) is a neuromodulator with neurotransmitter and neuroendocrine functions that contributes to tumorigenesis. We investigated the role of 5-HT signaling in the growth of pancreatic tumors.</P> <P><B>Methods</B></P> <P>We measured the levels of proteins that regulate 5-HT synthesis, packaging, and degradation in pancreata from Kras<SUP>G12D/+</SUP>/Trp53<SUP>R172H/+</SUP>/Pdx1-Cre (KPC) mice, which develop pancreatic tumors, as well as in PDAC cell lines and a tissue microarray containing 81 human PDAC samples. We also analyzed expression levels of proteins involved in 5-HT synthesis and degradation by immunohistochemical analysis of a tissue microarray containing 311 PDAC specimens, and associated expression levels with patient survival times. 5-HT level in 14 matched PDAC tumor and non-tumor tissues were analyzed by ELISA. PDAC cell lines were incubated with 5-HT and cell survival and apoptosis were measured. We analyzed expression of the 5-HT receptor HTR2B in PDAC cells and effects of receptor agonists and antagonists, as well as HTR2B knockdown with small hairpin RNAs. We determined the effects of 5-HT stimulation on gene expression profiles of BxPC-3 cells. Regulation of glycolysis by 5-HT signaling via HTR2B was assessed by immunofluorescence and immunoprecipitation analyses, as well as by determination of the extracellular acid ratio, glucose consumption, and lactate production. Primary PDACs, with or without exposure to SB204741 (a selective antagonist of HTR2B), were grown as xenograft tumors in mice, and SB204741 was administered to tumor-bearing KPC mice; tumor growth and metabolism were measured by imaging analyses.</P> <P><B>Results</B></P> <P>In immunohistochemical analysis of a tissue microarray of PDAC specimens, increased levels of TPH1 and decreased level of MAOA, which regulate 5-HT synthesis and degradation, correlated with stage and size of PDACs and shorter patient survival time. We found levels of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B–LYN–p85 complex, which increased PI3K–Akt–mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice.</P> <P><B>Conclusions</B></P> <P>Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice.</P>

Systemic Inflammatory Biomarkers, Especially Fibrinogen to Albumin Ratio, Predict Prognosis in Patients with Pancreatic Cancer

Lin Fang,Fei-Hu Yan,Chao Liu,Jing Chen,Dan Wang,Chun-Hui Zhang,Chang-Jie Lou,Jie Lian,Yang Yao,Bo-Jun Wang,Rui-Yang Li,Shu-Ling Han,Yi-Bing Bai,Jia-Ni Yang,Zhi-Wei Li,Yan-Qiao Zhang 대한암학회 2021 Cancer Research and Treatment Vol.53 No.1

Purpose Systemic inflammatory response is a critical factor that promotes the initiation and metastasis of malignancies including pancreatic cancer (PC). This study was designed to determine and compare the prognostic value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and fibrinogen-to-albumin ratio (FAR) in resectable PC and locally advanced or metastatic PC. Materials and Methods Three hundred fifty-three patients with resectable PC and 807 patients with locally advan-ced or metastatic PC were recruited in this study. These patients were classified into a training set (n=758) and a validation set (n=402). Kaplan-Meier survival plots and Cox proportional hazards regression models were used to analyze prognosis. Results Overall survival (OS) was significantly better for patients with resectable PC with low preoperative PLR (p=0.048) and MLR (p=0.027). Low FAR, MLR, NLR (p < 0.001), and PLR (p=0.003) were significantly associated with decreased risk of death for locally advanced or metastatic PC patients. FAR (hazard ratio [HR], 1.522; 95% confidential interval [CI], 1.261 to 1.837; p < 0.001) and MLR (HR, 1.248; 95% CI, 1.017 to 1.532; p=0.034) were independent prognostic factors for locally advanced or metastatic PC. Conclusion The prognostic roles of FAR, MLR, NLR, and PLR in resectable PC and locally advanced or metastatic PC were different. FAR showed the most prognostic power in locally advanced or metastatic PC. Low FAR was positively correlated with OS in locally advanced or metastatic PC, which could be used to predict the prognosis.

Knockdown of HMGN5 Expression by RNA Interference Induces Cell Cycle Arrest in Human Lung Cancer Cells

Chen, Peng,Wang, Xiu-Li,Ma, Zhong-Sen,Xu, Zhong,Jia, Bo,Ren, Jin,Hu, Yu-Xin,Zhang, Qing-Hua,Ma, Tian-Gang,Yan, Bing-Di,Yan, Qing-Zhu,Li, Yan-Lei,Li, Zhen,Yu, Jin-Yan,Gao, Rong,Fan, Na,Li, Bo,Yang, Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

HMGN5 is a typical member of the HMGN (high mobility group nucleosome-binding protein) family which may function as a nucleosomal binding and transcriptional activating protein. Overexpression of HMGN5 has been observed in several human tumors but its role in tumorigenesis has not been fully clarified. To investigate its significance for human lung cancer progression, we successfully constructed a shRNA expression lentiviral vector in which sense and antisense sequences targeting the human HMGN5 were linked with a 9-nucleotide loop. Inhibitory effects of siRNA on endogenous HMGN5 gene expression and protein synthesis were demonstrated via real-time RT-PCR and western blotting. We found HMGN5 silencing to significantly inhibit A549 and H1299 cell proliferation assessed by MTT, BrdU incorporation and colony formation assays. Furthermore, flow cytometry analysis showed that specific knockdown of HMGN5 slowed down the cell cycle at the G0/G1 phase and decreased the populations of A549 and H1299 cells at the S and G2/M phases. Taken together, these results suggest that HMGN5 is directly involved in regulation cell proliferation in A549 and H1299 cells by influencing signaling pathways involved in cell cycle progression. Thus, our finding suggests that targeting HMGN5 may be an effective strategy for human lung cancer treatment.

Applicability Analysis of Microseismic Technology in Tunnel Water Inrush Monitoring

Yan-hao Chen,Shuai Cheng,Li-Ping Li,Jun-yan Yang,Hong-liang Liu,Wen-feng Tu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.7

Water inrush disaster is one of the most serious geological disasters in tunnel construction. There are still some problems in the existing researches, such as the activity information of surrounding rock is difficult to obtain, the mechanism of water inrush disaster is unclear, the correlation between water inrush disaster and microseismic (MS) information is missing, which have caused the water inrush disaster to be passively controlled. Combining with the practical experience of tunnel engineering, the application problems of MS technology in tunnel engineering is summarized, which provides ideas for monitoring of surrounding rock activity. The formation mechanism of water inrush disaster caused by rock mass fracturing and filling medium instability has been revealed. The MS characteristics of the water inrush channel in different water inrush disasters have also been revealed. The MS response characteristics of water inrush and rockburst disasters are compared, which provides guidance for the improvement of MS monitoring technology and the analysis of effective MS information. The compression failure test of limestone under saturated and natural conditions is carried out. The results show that the presence of water weakens the ability of rock to store energy. The acoustic emission (AE) phenomenon is weaker in the process of saturated limestone failure, which increases the difficulty of AE monitoring. The number of AE events of natural limestone and saturated limestone shows a slow increase to a sudden increase in the process stress loading, which can be regarded as an important precursor of rock failure.

Improved photocatalytic performance of Pd-doped ZnO

Jun bo Zhong,Jian zhang Li,Xi yang He,Jun Zeng,Yan Lu,Wei Hu,Kun Lin 한국물리학회 2012 Current Applied Physics Vol.12 No.3

ZnO and Pd-doped ZnO photocatalysts with different molar ratio of Pd/Zn (1/100, 2/100, 3/100 and 4/100) were prepared by a solegel method. The photocatalysts prepared were characterized by BET surface area, X-ray diffraction (XRD), UV/vis diffuse reflectance (DRS) and surface photovoltage spectroscopy (SPS), respectively. The results show that doping Pd into ZnO decreases the BET surface area. The XRD spectra of the Pd-doped ZnO catalysts calcined at 773 K show only the characteristic peaks of wurtzite-type. Doping Pd into ZnO increases the absorbance of ZnO in visible region and enhances the photoinduced charge separation rate. The photocatalytic activity of Pd-doped ZnO photocatalysts for decolorization of methyl orange (MO) solution was evaluated, of all the photocatalysts prepared, the Pddoped ZnO with 3/100 possesses the best photocatalytic activity. The results of further experiments show that increased adsorption ability of light and high separation rate of photoinduced charge carriers all play an important role in promotion of photocatalytic activity of Pd-doped ZnO nanostructure.

Study of the Ultimate Load Capacity of K-Type Tube-Gusset Plate Connections

Yan-Zhong Ju,Jia-Yang Li,De-Hong Wang,Jun-Feng Bai 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2

In order to investigate the ultimate load capacity of K-type tube-gusset plate connections with stiff ened plate, the static tests of fi ve full-scale specimens were conducted in this study. The results indicate that the end stiff ened plate is critical for improving the load capacity of the connections. In addition, the parametric nonlinear fi nite element analysis of the K-type tube-gusset plate specimens was performed with account of such non-dimensional parameters as chord diameter-to-thickness ratio ( γ ), plate width-to-chord diameter ratio ( α ), plate thickness-to-chord thickness ratio ( 1 ), stiff ened plate thickness ( t d ), and nominal-to-yield stress ratio ( η ). The above analysis implies that the ultimate load capacity decreases with the increment of γ and increases with the increment of α and 1 , while it is only slightly aff ected by the stiff ened plate thickness. Compare the results of the fi nite element analysis with assessment by design guides existing. Based on the former results, an equation for estimating the load capacity of K-type tube-stiff ened gusset plate is proposed.

A comparative experimental study on the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films

Yang Gang,Pan Jiahui,Fu Xuecheng,Hu Zhiyu,Wang Ying,Wu Zhimao,Mu Erzhen,Yan Xue-Jun,Lu Ming-Hui 나노기술연구협의회 2018 Nano Convergence Vol.5 No.22

Thermoelectric multilayer thin films used in nanoscale energy conversion have been receiving increasing attention in both academic research and industrial applications. Thermal transport across multilayer interface plays a key role in improving thermoelectric conversion efficiency. In this study, the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films have been measured using time-domain thermoreflectance method. The interface morphology features of multilayer thin film samples were characterized by using scanning and transmission electron microscopes. The effects of interface microstructure on the cross-plane thermal conductivities of the multilayer thin films have been extensively examined and the thermal transfer mechanism has been explored. The results indicated that electron–phonon coupling occurred at the semiconductor/metal interface that strongly affected the cross-plane thermal conductivity. By appropriately optimizing the period thickness of the metal layer, the cross-plane thermal conductivity can be effectively reduced, thereby improving the thermoelectric conversion efficiency. This work presents both experimental and theoretical understanding of the thermal transport properties of Sb2Te3/metal multilayer thin film junctions with important implications for exploring a novel approach to improving the thermoelectric conversion efficiency. Introduction Thermoelectric multilayer thin films used in nanoscale energy conversion have been receiving increasing attention in both academic research and industrial applications. Thermal transport across multilayer interface plays a key role in improving thermoelectric conversion efficiency. In this study, the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films have been measured using time-domain thermoreflectance method. The interface morphology features of multilayer thin film samples were characterized by using scanning and transmission electron microscopes. The effects of interface microstructure on the cross-plane thermal conductivities of the multilayer thin films have been extensively examined and the thermal transfer mechanism has been explored. The results indicated that electron–phonon coupling occurred at the semiconductor/metal interface that strongly affected the cross-plane thermal conductivity. By appropriately optimizing the period thickness of the metal layer, the cross-plane thermal conductivity can be effectively reduced, thereby improving the thermoelectric conversion efficiency. This work presents both experimental and theoretical understanding of the thermal transport properties of Sb2Te3/metal multilayer thin film junctions with important implications for exploring a novel approach to improving the thermoelectric conversion efficiency. Introduction

Engineered biomaterials for development of nucleic acid vaccines

Jun Yang,Yan Li,Shubin Jin,Jing Xu,Paul C Wang,Xing-Jie Liang,Xin Zhang 한국생체재료학회 2015 생체재료학회지 Vol.19 No.1

Nucleic acid vaccines have attracted many attentions since they have presented some superiority over traditional vaccines. However, they could only induce moderate immunogenicity. The route and formulation of nucleic acid vaccines have strong effects on the immune response and efficiency. Numerous biomaterials are used as a tool to enhance the immunogenicity of antigens. They deliver the antigens into the cells through particle- and non-particle-mediated pathway. However, challenges remain due to lack of comprehensive understanding of the actions of these biomaterials as a carrier/adjuvant. Herein, this review focuses on the evolution of biomaterials used for nucleic acid vaccines, discusses the advantages and disadvantages for gene delivery and immunostimulation of variety of structures of the biomaterials, in order to provide new thought on rational design of carrier/adjuvant and better understanding of mechanism of action in both immunostimulatory and delivery methods.