Electronic and Optical Properties of Noble Metal Oxides M2O (M = Cu, Ag and Au): First-principles Study

Fei Pei,Song Wu,Gang Wang,Ming Xu,Liang-Yao Chen,Yu Jia,Song-You Wang 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

In this work, first-principles calculations for the structural, electronic, and optical properties of noble metal oxides M2O (M = Cu, Ag, Au) with the cuprite structure are performed by using a plane wave pseudopotential method in the framework of density functional theory (DFT) and the generalized gradient approximation (GGA). The structural, electronic, and optical properties are investigated and discussed. For Cu2O and Ag2O, good agreement was achieved between calculated and experimental results. Within the same framework, Au2O is predicted to be a semiconductor. In comparison with the copper and the silver oxides, the gold oxide has less ionic bonding between Au and O, and the intra-atomic hybridization is expected to be more evident as the depletion of the Au 5d shell appears to be more profound than it is for the Cu 3d and the Ag 4d shells. In this work, first-principles calculations for the structural, electronic, and optical properties of noble metal oxides M2O (M = Cu, Ag, Au) with the cuprite structure are performed by using a plane wave pseudopotential method in the framework of density functional theory (DFT) and the generalized gradient approximation (GGA). The structural, electronic, and optical properties are investigated and discussed. For Cu2O and Ag2O, good agreement was achieved between calculated and experimental results. Within the same framework, Au2O is predicted to be a semiconductor. In comparison with the copper and the silver oxides, the gold oxide has less ionic bonding between Au and O, and the intra-atomic hybridization is expected to be more evident as the depletion of the Au 5d shell appears to be more profound than it is for the Cu 3d and the Ag 4d shells.

물류ㆍ유통업체 온라인 쇼핑몰의 서비스공정성이 몰입 및 브랜드충성도에 미치는 연구

페페(Pei Fei),김철중(Kim Chul Jung) 한국물류학회 2017 물류학회지 Vol.27 No.2

본 연구의 목적은 물류ㆍ유통기업의 온라인 쇼핑몰의 이용자를 대상으로 서비스 공정성(분배 공정성, 절차 공정성, 상호작용 공정성)이 몰입과 브랜드 충성도에 미치는 영향을 분석하였다. 또한 이러한 요인들이 몰입을 매개로 브랜드충성도에 미치는 영향을 조사하고, 물류ㆍ유통기업의 온라인 쇼핑몰이 마케팅전략 수립에 의미 있는 시사점을 조사해보고자 한다. 조사를 위한 연구변수들은 문헌연구를 통해 기존 마케팅 연구에서 많이 적용되어 검증된 변수들을 선정하였다. 표본추출은 물류ㆍ유통기업의 온라인 쇼핑몰의 이용자를 대상으로 하였다. 연구모형은 변수간의 인과관계에 대하여 공분산 구조방정식모델(CB-SEM: Covariance Based Structural Equation Modeling)로 실증분석이 이루어졌다. 연구결과, 첫째, 서비스 공정성과 몰입의 관계 연구에 대한 결과를 살펴보면 분배 공정성이 몰입에 유의한 역방향 영향을 미치는 결과로 나타났고, 절차 공정성이 몰입에 유의한 영향을 미치지 못하는 것으로 나타났다. 그리고 상호작용공정성이 몰입에 유의한 영향을 미치는 것으로 나타났다. 둘째, 몰입과 브랜드 충성도의 관계에 대한 연구 결과를 조사해보면 몰입이 브랜드충성도에 유의한 영향을 미치는 것으로 나타났다. 셋째, 서비스공정성과 브랜드충성도의 관계에 대한 연구결과를 조사해보면, 분배공정성과 상호작용공정성이 브랜드충성도에 유의한 영향을 미치는 것으로 나타났다. 절차 공정성이 브랜드 충성도에 유의한 역방향 영향을 미치는 것으로 나타났다. 넷째, 물류ㆍ유통기업 온라인 쇼핑몰의 서비스 공정성(분배 공정성, 절차 공정성, 상호작용 공정성)이 브랜드 충성도에 미치는 영향에 있어 몰입의 매개적 역할을 분석하였다. 조사결과 매개역할이 있는 것으로 조사되었다. 본 연구는 물류ㆍ유통기업의 온라인 쇼핑몰의 몰입과 브랜드 충성도 관계를 분석했으며 몰입의 매개역할의 중요성을 발견한 것이 본 논문의 의미라 할 수 있다. The study is to analyze the influence of service justice(distributive justice, procedural justice, interactional justice) on the commitment and brand loyalty for users of online shopping mall of logistics and distribution companies. The purpose of this study is to investigate the influence of these factors on brand loyalty through immersion and to examine meaningful implications for marketing strategy of online shopping mall of logistics and distribution companies. The research variables for the survey were selected as the variables that were widely applied and validated in the existing marketing research through the literature review. Sampling was conducted for users of online shopping malls of logistics and distribution companies. The research model was empirically analyzed by Covariance Based Structural Equation Modeling (CB-SEM) on causality between variables. As a results, this study are as follows: First, the research on the relationship between service justice and commitment show that commitment has a significant positive(+) effect on the distributive justice, and procedural justice has no effect on commitment. interactional justice have a significant positive (+) effect on commitment. Second, when we research on the relationship between commitment and brand loyalty, it shows that commitment has a significant positive(+) effect on brand loyalty. Third, research on the relationship between service justice and brand loyalty showed that distributive justice and interactional justice had a significant positive (+) effect on brand loyalty. Brand loyalty has a positive (+) effect on procedural justice. Fourth, the influence of service justice (distributive justice, procedural justice, interactional justice) on brand loyalty through out the mediation effect of commitment of online shopping malls in distribution and logistics companies show that commitment has mediation effect between the service justice and brand loyalty. This study analyzed the relationship between shopping mall and brand loyalty of logistics and distribution companies, and the importance of the mediation effect of commitment is found in the meaning of this paper.

Identification of novel rheumatoid arthritis-associated MiRNA-204-5p from plasma exosomes

Wu Long-Fei,Zhang Qin,Mo Xing-Bo,Lin Jun,Wu Yang-Lin,Lu Xin,He Pei,Wu Jian,Guo Yu-Fan,Wang Ming-Jun,Ren Wen-Yan,Deng Hong-Wen,Lei Shu-Feng,Deng Fei-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Rheumatoid arthritis (RA) is an autoimmune disease characterized by infiltration of immune cells in the synovium. However, the crosstalk of immune cells and synovial fibroblasts is still largely unknown. Here, global miRNA screening in plasma exosomes was carried out with a custom microarray (RA patients vs. healthy controls = 9:9). A total of 14 exosomal miRNAs were abnormally expressed in the RA patients. Then, downregulated expression of exosomal miR-204-5p was confirmed in both the replication (RA patients vs. healthy controls = 30:30) and validation groups (RA patients vs. healthy controls = 56:60). Similar to the findings obtained in humans, a decreased abundance of exosomal miR-204-5p was observed in mice with collagen-induced arthritis (CIA). Furthermore, Spearman correlation analysis indicated that plasma exosomal miR-204-5p expression was inversely correlated with disease parameters of RA patients, such as rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein. In vitro, our data showed that human T lymphocytes released exosomes containing large amounts of miR-204-5p, which can be transferred into synovial fibroblasts, inhibiting cell proliferation. Overexpression of miR-204-5p in synovial fibroblasts suppressed synovial fibroblast activation by targeting genes related to cell proliferation and invasion. In vivo assays found that administration of lentiviruses expressing miR-204-5p markedly alleviated the disease progression of the mice with CIA. Collectively, this study identified a novel RA-associated plasma exosomal miRNA-204-5p that mediates the communication between immune cells and synovial fibroblasts and can be used as a potential biomarker for RA diagnosis and treatment.

Large Second-Order Nonlinearity from a Dip-Coated Pure Dye (4-(2-(3,3-Dicyanomethylene-5,5-Dimethyl-1-Cyclohexylidene) Vinyl)Phenyl(1-Naphthyl)Phenylamine) Thin Film

Pei Yang,Huiying Fu,Liying Liu,Liyong Ji,Lei Xu,Fei Xiao 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.5I

We found that the pure dye 4-(2-(3,3-dicyanomethylene-5,5-dimethyl-1-cyclohexylidene)vinyl) phenyl(1-naphthyl)phenylamine can form a solid-state thin film up to 31 nm in thickness by simple dip-coating. After electric poling, the molecular film was very well oriented along the poling field’s direction (ordering parameter = 0.36). The poled film gave a large resonant second-harmonic generation (SHG) signal ((2) = 591 pm/V when using 1064-nm laser light as the fundamental light) and non-resonant SHG ((2) = 232 pm/V when using 800-nm laser light as the fundamental light). The results show that such molecules can find applications in nonlinear photonic integrated circuits.

The effect of chitosan (CS) coagulation bath on structure and performance of polylactic acid (PLA) microfiltration membrane

Fei Liu,Bing-Bing Li,De Sun,Fenggang Li,Xinyue Pei 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.5

Membrane hydrophilicity is a crucial factor in evaluating ultrafiltration processes. In this paper, chitosan(CS) was selected for the hydrophilic modification of the polylactic acid (PLA) membrane, and PLACS membranes wereprepared for the densification of the yeast solution. By non-solvent phase inversion method (NIPS), the PLACS microfiltrationmembranes were prepared by using chitosan (CS) acetic acid solution as the coagulation bath and glutaraldehydeas the crosslinking agent. PLACS membranes were characterized by water contact angle, porosity, pore sizedistribution, mechanical properties, ATR-FTIR, SEM, TGA and the ultrafiltration experiment. The viscosity of coagulationbath solution can severely influence the exchange rate of the solvent and the non-solvent as well during phaseinversion; therefore, it can regulate the precipitation kinetics and membrane morphology. The results showed that chitosan(CS) was presented as granular on the pore surfaces of the PLACS membranes. When chitosan (CS) contentincreased, gel rate became smaller and membrane forming process was prolonged; the porosity and pore size of thePLACS were increased compared to the polylactic acid (PLA) membrane, pure water flux increased from 90.31 L·m2·h1to 120.14 L·m2·h1, and yeast rejection rate increased from 75% to more than 90%.

Effects of Exogenous Elicitors on Triterpenoids Accumulation and Expression of Farnesyl Diphosphate Synthase Gene in Inonotus obliquus

Pei Lin,Zheng-Fei Yan,Chang-Tian Li 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.4

Exogenous elicitors can influence accumulation of triterpenoids by regulating FPS (farnesyl pyrophosphate synthase) in Inonotus obliquus, such as birch bark (BB), birch rhizosphere soil (BS), Frankia alni (FA), and Rhizobium indigoferae (RI). Among them, the highest yield of biomass (15.6 mg/mL) could be detected by treatment with RI at 2 μg/mL for 10 d, about 2.1-fold of the control. Results showed the significant effect of elicitors on accumulation of triterpenoids by regulating FPS expression level. RI stimulated mycelium to achieve the highest accumulation of triterpenoids about 48.2 mg/g, which was about over 4-fold of the control (9.5 mg/g). Its effect on FPS expression level was greater than that of others, which was about over 10-fold of the control. However, accumulation of triterpenoids and FPS expression level were clearly down-regulated under treatment with BS. In addition, two endogenous factors (H2O2 and NO) in I. obliquus could affect accumulation of triterpenoids by regulating FPS expression level. Effect of RI on H2O2 and NO contents were higher than that of others, about 3.5-fold of the control. The minimum value of H2O2 content was detected by treatment with BS for 10 d, which was about 0.5-fold of the control. RI that assist with CAT (catalase) and SNP (sodium nitroprusside dehydrate) could stimulate triterpenoid contents to achieve highest accumulation, which was about 5.5-fold of the control. Fluctuation of H2O2 and NO content seems to play a pivotal role in accumulation of triterpenoids by regulating FPS expression level.

An Enhancement of Antibacterial Activity and Synergistic Effect of Biosynthesized Silver Nanoparticles by Eurotium cristatum with Various Antibiotics

Pei Lin,Fu-Qing Wang,Chang-Tian Li,Zheng-Fei Yan 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.3

In this study, biosynthesis of silver nanoparticles (AgNPs) by using Eurotium cristatum, isolated from Fuzhuan brick-tea and its antibacterial activity has been demonstrated. AgNPs were characterized at 425 nm as maximum absorbance peak by ultraviolet-visible spectrophotometry. The images of transmission electron microscopy revealed that AgNPs are spherical shape with at 15-20 nm in size. The X-ray diffraction pattern corresponding to planes (111), (200), (220), (311), and (222) demonstrated the crystalline nature of AgNPs. Fourier transform infrared spectrum showed that functional groups involved in reduction of silver ions to metal nanoparticles. For antibacterial application, AgNPs showed antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Candida albicans, and Bacillus subtilis. It also acted synergistically with various antibiotics to inhibit growth of pathogenic strains, which produced an effect greater than the sum of their individual effects. For neomycin with no resistance to C. albicans, it combined with AgNPs, which had significant synergistic effect against C. albicans, with maximum inhibitory zone at 20.9 mm, which was 2.5-fold greater than that of AgNPs alone (8.2 mm). Other antibiotics combined with AgNPs also existed similar synergistic effect. Therefore, AgNPssynthesized by E. cristatum could enhance antibacterial activity in combination with antibiotics against pathogenic strains through synergistic effects. It might provide a new strategy for treatment of resistant bacteria.

Paracoccus hibiscisoli sp. nov., isolated from the rhizosphere of Mugunghwa (Hibiscus syriacus)

Lin, Pei,Yan, Zheng-Fei,Won, Kyung-Hwa,Yang, Jung-Eun,Li, Chang-Tian,Kook, MooChang,Wang, Qi-Jun,Yi, Tae-Hoo Microbiology Society 2017 International journal of systematic and evolutiona Vol.67 No.7

Camelliibacillus cellulosilyticus gen. nov., sp. nov., a cellulose-degrading bacterium isolated from tea

Lin, Pei,Yan, Zheng-Fei,Yi, Tae-Hoo Microbiology Society 2018 International journal of systematic and evolutiona Vol.68 No.6

A Simple Isocratic HPLC Method for the Simultaneous Determination of Sinensetin, Eupatorin, and 30-hydroxy-5,6,7,4'-tetramethoxyflavone in Orthosiphon stamineus Extracts

Mun Fei Yam,Elsnoussi Ali Hussin Mohamed,Lee Fung Ang,Li Pei,Yusrida Darwis,Roziahanim Mahmud,Mohd. Zaini Asmawi,Rusliza Basir,Mariam Ahmad,유혜현,김동현,정혜진 사단법인약침학회 2012 Journal of Acupuncture & Meridian Studies Vol.5 No.4

Orthosiphon stamineus extracts contain three flavonoids (3’-hydroxy-5, 6, 7, 4’-tetramethoxyflavone, sinensetin, and eupatorin) as bioactive substances. Previous reported high performance liquid chromatography- ultraviolet (HPLC-UV) methods for the determination of these flavonoids have several disadvantages, including unsatisfactory separation times and not being well validated according to International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) standard guidelines. A rapid, specific reversed-phase HPLC method with isocratic elution of acetonitrile: isopropyl alcohol: 20 mM phosphate buffer (NaH2-PO4) (30:15:55, v/v) (pH 3.5) at a flow-rate of 1 ml/minute, a column temperature of 25_C, and ultraviolet (UV) detection at 340 nm was developed. The method was validated and applied for quantification of different types of O stamineus extracts and fractions. The method allowed simultaneous determination of 3’-hydroxy-5,6,7,4’- tetramethoxyflavone, sinensetin, and eupatorin in the concentration range of 0.03052 e250 mg/ml. The limits of detection and quantification, respectively, were 0.0076 and 0.061 mg/ml for 3’-hydroxy-5,6,7,4’-tetramethoxyflavone, 0.0153 and 0.122 mg/ml for sinensetin and 0.0305 and 0.122 mg/ml for eupatorin. The percent relative standard deviation (% RSD) values for intraday were 0.048e0.368, 0.025e0.135, and 0.05e0.476 for 3’-hydroxy-5,6,7,4’-tetramethoxyflavone, sinensetin, and eupatorin, respectively, and those for intraday precision were 0.333e1.688, 0.722e1.055, and 0.548e1.819, respectively. The accuracy for intraday were 91.25%e103.38%, 94.32%e109.56%, and 92.85%e109.70% for 30-hydroxy-5,6,7,40-tetramethoxyflavone, sinensetin, and eupatorin, respectively, and those for interday accuracy were 97.49%e103.92%, 103.58% e104.57%, and 103.9%e105.33%, respectively. The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of O stamineus extract containing the three flavonoids as the principle components in the extract.