Development of lattice inversion modified embedded atom method and its applications

Xianbao Duan,Bing Zhou,Rong Chen,Huamin Zhou,YanweiWen,Bin Shan 한국물리학회 2014 Current Applied Physics Vol.14 No.12

The modified embedded atom method (MEAM) has been widely used in describing the physical properties of elemental crystals, alloys and compounds with multiple lattice structures. We report here the development of a reliable procedure to reduce the complexity of the MEAM formalism by removing the many-body screening function. In the proposed formulation, the interatomic pair potential is obtained by applying Chen-M€obius lattice inversion up to fifth nearest neighbors, so that the cohesive energy curve can be reproduced faithfully. The newly developed model (Lattice Inversion MEAM, LI-MEAM), which can be viewed as a direct extension of the embedded atom method (EAM), no longer requires the computation of many-body screen functions and has fewer adjustable parameters than MEAM. As an illustration, we optimized the potential parameters of body centered cubic iron (bcc-Fe). The values of the calculated physical properties agree well with experimental results. We further investigated the sizedependent melting behavior of bcc-Fe nanoparticles (NPs) with particle size ranging from 725-atom (~25 Å) to 22899-atom (~80 Å) using replica exchange molecular dynamics (REMD) simulations. Our simulations show advantages of LI-MEAM in modeling of the melting process and quantitatively reveals that the liquid skin melting (LSM) process of bcc-Fe NPs.

An Electrochemical Sensor Based on Graphene-Polypyrrole Nanocomposite for the Specific Detection of Pb (II)

Rong Rong,Huimin Zhao,Xiao Rong Gan,Shuo Chen,Xie Quan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.1

An electrochemical sensor for the rapid, selective and sensitive detection of Pb2+ was developed using polypyrrole-graphene (PPY-rGO) nanocomposite by electrochemical synthesis. The PPYrGO-modified electrode possessed a large effective area because of unique 3D porous architectures, and it displayed excellent selectivity for the determination of Pb2+. The response of Pb2+ on the nanocomposite-modified electrode was evaluated, and the relevant parameters were optimized by square wave anodic stripping voltammetry (SWASV). The stripping response was highly linear (R2 = 0.987) over a Pb2+ concentration range of 5 X 10-9 mol/L to 7.5 X 10-7 mol/L, with a detection limit of 4.7 X 10-11 mol/L (3σ method). Furthermore, its applicability was validated for the determination of Pb2+ levels using spiked tap water at different concentrations. The polyporous structure, satisfactory reproducibility, long-term stability and simple synthesis endow the PPY-rGO nanocomposite a promising application in the determination of Pb2+.

Oridonin Suppresses Proliferation of Human Ovarian Cancer Cells via Blockage of mTOR Signaling

Xia, Rong,Chen, Sun-Xiao,Qin, Qin,Chen, Yan,Zhang, Wei-Wei,Zhu, Rong-Rong,Deng, An-Mei Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Oridonin, an ent-kaurane diterpenoid compound isolated from the traditional Chinese herb Rabdosia rubescens, has shown various pharmacological and physiological effects such as anti-tumor, anti-bacterial, and anti-inflammatory properties. However, the effect of oridonin on human ovarian cancer cell lines has not been determined. In this study, we demonstrated that oridonin inhibited ovarian cancer cell proliferation, migration and invasion in a dose-dependent manner. Furthermore, we showed oridonin inhibited tumor growth of ovarian cancer cells (SKOV3) in vivo. We then assessed mechanisms and found that oridonin specifically abrogated the phosphorylation/activation of mTOR signaling. In summary, our results indicate that oridonin is a potential inhibitor of ovarian cancer by blocking the mTOR signaling pathway.

Study on Folk Embroidered Shoes in Waterside Villages of Southern Yangtze during the Period of Min Guo in China

( Rong Rong Cui ),( Hui E Liang ),( Dong Sheng Chen ) 한국의류산업학회 2005 Clothing Research Journal Vol.3 No.2

Effects of Using Various Production Methods And Different Molecular Weight Chitosans On Gel Strength And Release Characteristics of Prepared Hydrogels

(Rong Huei Chen) 한국키틴키토산학회 2000 한국키틴키토산학회지 Vol.5 No.3

Effects of Green Operations and Green Innovation on Firm's Environmental Performance

Chen, Rong-Huei Korean Institute of Industrial Engineers 2014 Industrial Engineeering & Management Systems Vol.13 No.2

This study examines how green operations affect firm's environmental performance with green innovation as a mediator in the context of electronic industry. We carry out an empirical study with 141 valid questionnaires collected from high-tech manaufactures in Taiwan. The results show that positive relationships exist among green operations, green innovation and environmental performance (in both operational performance and managerial performance). However, an integration of green operations with green innovation would influence firm's environmental performance more positively than the sole effects of green operations. It suggests that high-tech manufacturers should pay greater attention to green innovative strategies in order to cope with customer demand and, thereby, enhancing customer satisfaction and sustainable operations. This study has contributed to the extant literature by providing valuable academic references and pragmatic guidelines for firms to gain competitive advantages through green operations and green innovation.

Analysis and Design of a New Topology of Soft-Switching Inverters

Rong Chen,Jia-Sheng Zhang 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.1

This paper proposes the power conversion mechanism of a bailer-charge-transfer zero-current-switching (CT-ZCS) circuit. The operation modes are analyzed and researched using state trajectory equations. The topology of CT-ZCS based on soft-switching inverters offers some merits such as: tracking the input reference signal dynamically, bearing load shock and short circuit, multiplying inverter N+1 redundancy parallel, coordinating power balance for easy control, and soft-switching commutation for high efficiency and large capacity. These advantages are distinctive from conventional inverter topologies and are especially demanded in AC drives: new energy generation and grid, distributed generation systems, switching power amplifier, active power filter, and reactive power compensation and so on. Prototype is manufactured and experiment results show the feasibility and dynamic voltage-tracking characteristics of the topology.

Molecular Cloning of Two Genes Encoding Cinnamate 4-Hydroxylase (C4H) from Oilseed Rape (Brassica napus)

Chen, An-He,Chai, You-Rong,Li, Jia-Na,Chen, Li Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.2

Cinnamate 4-hydroxylase (C4H) is a key enzyme of phenylpropanoid pathway, which synthesizes numerous secondary metabolites to participate in development and adaption. Two C4H isoforms, the 2192-bp BnC4H-1 and 2108-bp BnC4H-2, were cloned from oilseed rape (Brassica napus). They both have two introns and a 1518-bp open reading frame encoding a 505-amino-acid polypeptide. BnC4H-1 is 57.73 kDa with an isoelectric point of 9.11, while 57.75 kDa and 9.13 for BnC4H-2. They share only 80.6% identities on nucleotide level but 96.6% identities and 98.4% positives on protein level. Showing highest homologies to Arabidopsis thaliana C4H, they possess a conserved p450 domain and all P450-featured motifs, and are identical to typical C4Hs at substrate-recognition sites and active site residues. They are most probably associated with endoplasmic reticulum by one or both of the N- and C-terminal transmembrane helices. Phosphorylation may be a necessary post-translational modification. Their secondary structures are dominated by alpha helices and random coils. Most helices locate in the central region, while extended strands mainly distribute before and after this region. Southern blot indicated about 9 or more C4H paralogs in B. napus. In hypocotyl, cotyledon, stem, flower, bud, young- and middle-stage seed, they are co-dominantly expressed. In root and old seed, BnC4H-2 is dominant over BnC4H-1, with a reverse trend in leaf and pericarp. Paralogous C4H numbers in Brassicaceae genomes and possible roles of conserved motifs in 5' UTR and the 2nd intron are discussed.

Prognostic Significance of CD44v6/v7 in Acute Promyelocytic Leukemia

Chen, Ping,Huang, Hui-Fang,Lu, Rong,Wu, Yong,Chen, Yuan-Zhong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

CD44v, especially splice variants containing exon v6, has been shown to be related closely to development of different tumors. High levels of CD44v6/v7 have been reported to be associated with invasiveness and metastasis of many malignancies. The objective of this study was to detect expression of CD44v6-containing variants in patients with acute promyelocytic leukemia (APL) and evaluate the potential of CD44v6/v7 for risk stratification. Reverse transcription polymerase chain reaction (RT-PCR) followed by PCR product purification, ligation into T vectors and positive clone sequencing were used to detect CD44 v6-containing variant isoforms in 23 APL patients. Real-time quantitative PCR of the CD44v6/v7 gene was performed in patients with APL and in NB4 cells that were treated with all-trans retinoic acid (ATRA) or arsenic trioxide ($As_2O_3$). Sequencing results identified four isoforms (CD44v6/v7, CD44v6/v8/v10, CD44v6/v8/v9/v10, and CD44v6/v7/v8/v9/v10) in bone marrow mononuclear cells of 23 patients with APL. The level of CD44v6/v7 in high-risk cases was significantly higher than those with low-risk. Higher levels of CD44v6/v7 were found in three patients with central nervous system relapse than in other patients inthe same risk group. Furthermore, in contrast to ATRA, only $As_2O_3$ could significantly down-regulate CD44v6/v7 expression in NB4 cells. Our data suggest that CD44v6/v7 expression may be a prognostic indicator for APL.

Modified Dual-Buck Inverter Based on Resonant Link

Rong Chen,Jia-Sheng Zhang,Wei Liu 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.6

The efficiency and reliability of the dual-buck inverter (DBI) were greatly improved by eliminating the shoot-through problem and optimally designing the freewheeling diode. The traditional DBI suffers from large harmonic components with low output voltage and large capacity output filter inductor. To overcome the aforementioned disadvantages, a modified DBI (MBDI) was proposed by adopting a quasi-resonant link and pulse density modulation (PDM). This paper first introduces the working principle of the MBDI and PDM, and then the selection principle of system parameters is presented. Finally, a mathematical model of the MBDIis built, and an experiment prototype is set up. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the scheme.