W(110) 표면에 CO의 흡착

이경희,유위량,한현석,부진효,이순보,곽현태 성균관대학교 기초과학연구소 1998 論文集 Vol.49 No.-

The interaction of CO with W(110) surface was investigated through LEED, TDS, and photoelectron spectroscopy using synchrotron radiation under UHV condition. After CO saturation at RT, two desorption states, called α and β , were observed at about 400 and 1150 K in thermal desorption spectra, respectively. The kinetics of 3-CO followed the first order kinetics, indicating the existence of molecular CO on W(110) surface. This is contrary to the previous results. The O 1s BE(binding energy) of CO adsorbed on W(110) surface at room temperature was 529.9 eV. On the other hand, the O 1s BE of β-CO after heating to 900 K was different from that of oxygen adsorbed W(110) surface, suggesting a different adsorption state. According to the UP valence band spectra, we observed two peaks at near -10.7 eV (4σ) and -7.0 eV (5σ+1π), indicating the molecular adsorption of CO at room temperature. Furthermore we could see the 4σ peak at the various photon energy and elevated temperatures. Comparing the energy separation, Δ(4σ-1π) , between 4σ and 1π UP peaks of chemisorbed CO, we found that an increased separation reflects an decreased C-O bond strength. Therefore on the basis of TDS and photoelectron spectroscopy, we could suggest that β state of CO on W(110) may not be dissociated and has an adsorption geometry of lying-down mode.

Breviscapine Ameliorates Fear Extinction and Anxiety in BALB/cJ Mice

Wei Liang(Wei Liang),Jing Huang(Jing Huang),Shuya Yang(Shuya Yang),Peng Huang(Peng Huang),Jun Chen(Jun Chen),Chen Chen(Chen Chen),Qun Yang(Qun Yang),Fengzhan Li(Fengzhan Li) 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.3

Objective In this research, the influence of breviscapine on anxiety, fear elimination, and aggression and the potential mechanism was investigated. Methods Anxiety and locomotion were analyzed by elevated plus maze and open field test in mice. Bussey-Saksida Mouse Touch Screen Chambers were used to perform fear conditioning. Territorial aggression was assessed by resident intruder test. Protein levels were evaluated by Western blot. Breviscapine improved fear-extinction learning in BALB/cJ mice. Results Breviscapine at 20-100 mg/kg increased center cross number, total distance traveled, and velocity in a dose-dependent manner. On the other hand, breviscapine at 20-100 mg/kg decreased the immobility time in open field test. In addition, breviscapine at 20-100 mg/kg increased the ratio of time on the open arm, time on the distal parts of the open arm, and total distance traveled in elevated plus maze. Breviscapine at 100 mg/kg increased the average attack latency and decreased the number of attacks over the last 3 days of resident intruder test. In hippocampus, protein levels of postsynaptic density protein-95 and synaptophysin were elevated by breviscapine at these three doses. Conclusion The administration of breviscapine alleviates fear extinction, anxiety, and aggression, while increases locomotor in a dose-dependent manner, which might be associated with its influence on synaptic function.

Axial compressive behavior of concrete-filled steel tube columns with stiffeners

Wei Liang,Jiangfeng Dong,Qingyuan Wang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.2

In order to reduce the deformation and delay the local buckling of concrete filled steel tube (CFST) columns, strengthening the structures with stiffeners is an effective method. In this paper, a new stiffening method with inclined stiffeners was used to investigate the behaviors of short CFST columns under axial compression. Besides, a three-dimensional nonlinear finite element (FE) model was applied to simulate the mechanical performances, including the total deformation, local buckling, and stress-strain relationship. Revised constitutive models of stiffened steel tube and confined concrete are proposed. A good agreement was achieved between the test and FE results. Furthermore, the calculated results of load capacity by using a simplified method also show a good correlation with experimental data.

Network Intrusion Detection Model With Clustering Ensemble Method

Liang-Wei Chen 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.11

As network techniques have become one of the most significant aspects of our daily lives, network security has been a major concern. One common application is network intrusion detection. From the perspective of data oriented consideration, intrusion detection can be formulated as a clustering task, which aims to differentiate normal and insecurity behaviors and categorize into several groups. In this paper, we employ ensemble clustering method to improve the generalization and robustness of basic clustering. Specifically, we employ fuzzy kernel C-means (FKCM) as basic clustering, which improves the fuzzy C-means (FCM) clustering by introducing kernels from the support vector machines (SVM) to optimize the features of sample data by mapping the sample pattern into a higher dimensional feature space. Then, we formulate the ensemble problem as the optimization of the mutual information among all clusterings and introduce Ant Colony Optimization (ACO) as the solution. Experiments prove the efficiency of our method.

Synthesis, Application, and Recovery of Alkali-Clearable Disperse Dyes Containing Azo Pyridone Structure

Liang Jin,Tao Qian,Ren-Liang Wang,Tao Zhu,Wei-Guo Chen,Hua Jiang,Zhi-Hua Cui 한국섬유공학회 2022 Fibers and polymers Vol.23 No.4

Carboxylic acid ester disperse dyes containing an azo pyridone structure have a high molar extinction coefficient,excellent washing color fastness, and simple synthetic methods. Dyes were readily synthesized through a conventional diazocoupling reaction between the reactant ethyl p-aminobenzoate and a coupling component containing an azo pyridonestructure. Subsequently, the molecular structures of the target products were characterized by FTIR, mass spectrometry,1H NMR, 13C NMR, UV-vis absorption spectroscopy, and elemental analysis. The synthesized dyes were used to dyepoly(ethylene terephthalate) fabric, and their washing and rubbing color fastness properties were tested and compared underdifferent post-treatment methods. Moreover, under the condition of alkali clearing, the relationships among different alkaliconcentrations and clearing effects were studied to determine the optimal alkali clearing process conditions for dyed fabrics,and the minimum alkali consumption required to obtain the best results was determined. It was found that carboxylic esterdisperse dyes containing an azo pyridone structure showed good dyeing performance and alkali-clearable properties onpolyester fibers. In addition, in hydrolyzate recovery, BaCl2 (salting out) can be used instead of acidification to recover thedye hydrolyzate, which has good environmental benefits.

Effects of drying methods on contents of bioactive compounds and antioxidant activities of Angelica dahurica

Wei-Hong Liang,Tung-Wu Chang,Yuh-Chyang Charng 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.4

Baizhi (Angelica dahurica) has been widely used as a traditional Chinese herbal medicine, functional food and cosmetic product ingredient, mostly because of the high furanocoumarin compounds in roots. Because the fresh root is perishable, drying techniques are needed to maintain a higher-quality product. Freeze-drying is the best method but energy-consuming and costly. The aim of this study was to analyze the quality (antioxidant and furanocoumarin content) of Baizhi roots after freeze-drying (the control) and in-the-shade, 40 and 70 C drying. Antioxidant activity was revealed by 2,2-diphenyl-1- picrylhydrazyl and Fe2? chelating assay, and the content of six furanocoumarin compounds, including xanthotoxin, bergapten, oxypeucedanin, imperatorin, phellopterin and isoimperatorin, was analyzed by liquid chromatography. Antioxidant activity was greater in roots with in-the-shade, 40 and 70 C drying than freeze-drying. The furanocoumarin content pattern was similar with 70 C drying and freeze-drying. A. dahurica roots dried at 70 C may be an alternative method for maintaining high quality.

Advantage of LC-MS Metabolomics to Identify Marker Compounds in Two Types of Chinese Dark Tea after Different Post-fermentation Processes

Liang Zhang,Wei-Wei Deng,Xiao-chun Wan 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.2

Chinese dark tea (CDT) was investigated forchemical characteristics using liquid chromatography coupledwith tandem mass spectrometry (LC-MS) metabolomicsanalysis. The LC-MSn method was used for detection ofsecondary metabolites in 10 CDT varieties. Pattern recognitionmethods, including principal component analysis (PCA)and orthogonal projection on latent structure-discriminantanalysis (OPLS-DA), revealed clear differences and classifiedthe CDT varieties into 2 categories. One category isfermented with Aspergillus niger while the other (fu teas)is fermented with Eurotium cristatum. Chemical analysesidentified 25 marker compounds that contribute to theclassification of the 2 CDT types. Flavonoid triglycosidesand catechin derivatives were the distinctive compounds offu teas, based on MS/MS fragmentation analysis. Althoughboth fu teas and dark teas are commonly called CDTs,differences between these two CDT types are significant inthe chemical classification.

Breviscapine Ameliorates Fear Extinction and Anxiety in BALB/cJ Mice

Liang Wei,Huang Jing,Yang Shuya,Huang Peng,Chen Jun,Chen Chen,Yang Qun,Li Fengzhan 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.4

Objective In this research, the influence of breviscapine on anxiety, fear elimination, and aggression and the potential mechanism was investigated.Methods Anxiety and locomotion were analyzed by elevated plus maze and open field test in mice. Bussey-Saksida Mouse Touch Screen Chambers were used to perform fear conditioning. Territorial aggression was assessed by resident intruder test. Protein levels were evaluated by Western blot. Breviscapine improved fear-extinction learning in BALB/cJ mice.Results Breviscapine at 20–100 mg/kg increased center cross number, total distance traveled, and velocity in a dose-dependent manner. On the other hand, breviscapine at 20–100 mg/kg decreased the immobility time in open field test. In addition, breviscapine at 20–100 mg/kg increased the ratio of time on the open arm, time on the distal parts of the open arm, and total distance traveled in elevated plus maze. Breviscapine at 100 mg/kg increased the average attack latency and decreased the number of attacks over the last 3 days of resident intruder test. In hippocampus, protein levels of postsynaptic density protein-95 and synaptophysin were elevated by breviscapine at these three doses.Conclusion The administration of breviscapine alleviates fear extinction, anxiety, and aggression, while increases locomotor in a dose-dependent manner, which might be associated with its influence on synaptic function.

Biotransformation of Panax ginseng extract by rat intestinal microflora

Wei-Wei Dong,Jinhua Zhao,Fei-Liang Zhong,Wen-Jing Zhu,Jun Jiang,Songquan Wu,Deok-Chun Yang,Donghao Li,Lin-Hu Quan 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.4

Background: In general, after Panax ginseng is administered orally, intestinal microbes play a crucial role in its degradation and metabolization process. Studies on the metabolism of P. ginseng by microflora are important for obtaining a better understanding of their biological effects. Methods: In vitro biotransformation of P. ginseng extract by rat intestinal microflora was investigated at 37C for 24 h, and the simultaneous determination of the metabolites and metabolic profile of P. ginseng saponins by rat intestinal microflora was achieved using LCeMS/MS. Results: A total of seven ginsenosides were detected in the P. ginseng extract, including ginsenosides Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd. In the transformed P. ginseng samples, considerable amounts of deglycosylated metabolite compound K and Rh1 were detected. In addition, minimal amounts of deglycosylated metabolites (ginsenosides Rg2, F1, F2, Rg3, and protopanaxatriol-type ginsenosides) and untransformed ginsenosides Re, Rg1, and Rd were detected at 24 h. The results indicated that the primary metabolites are compound K and Rh1, and the protopanaxadiol-type ginsenosides were more easily metabolized than protopanaxatriol-type ginsenosides. Conclusion: This is the first report of the identification and quantification of the metabolism and metabolic profile of P. ginseng extract in rat intestinal microflora using LCeMS/MS. The current study provided new insights for studying the metabolism and active metabolites of P. ginseng.

Esophageal Bolus Domain Pressure and Peristalsis Associated With Experimental Induction of Esophagogastric Junction Outflow Obstruction

( Wei-yi Lei ),( Taher Omari ),( Tso-tsai Liu ),( Ming-wun Wong ),( Jui-sheng Hung ),( Chih-hsun Yi ),( Shu-wei Liang ),( Charles Cock ),( Chien-lin Chen ) 대한소화기기능성질환·운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.1

Background/Aims Intrabolus pressures are important for esophageal bolus transport and may detect obstructed bolus flow. This study measured the effect esophageal outflow obstruction experimentally induce by a leg-lift protocol. Methods Twenty-five gastroesophageal reflux disease patients referred for esophageal manometry and a normal motility diagnosis were included. Supine liquid swallows were tested. Leg-lift protocol generated esophageal outflow obstruction by increasing abdominal pressure. Esophageal pressure topography and intrabolus pressure metrics were calculated. These included, (1) mid-domain bolus distension pressure during esophageal emptying (DPE, mmHg) and (2) ramp pressure (mmHg/sec), generated by compression of the bolus between the peristaltic contraction and esophagogastric junction (EGJ). Results EGJ relaxation pressure was increased by leg-lift from 13 (11-17) to 19 (14-30) mmHg (P < 0.005) and distal contractile integral also increased from 1077 (883-1349) to 1620 (1268-2072) mmHgㆍcmㆍsec (P < 0.001) as a physiological response to obstruction. All bolus pressures were increased by leg lift; DPE increased from 17 (15-20) to 27 (19-32) mmHg (P < 0.001), and ramp pressure increased from 3 (1-4) to 5 (2-9) mmHg/sec (P < 0.05). Conclusion Measuring pressures within the intrabolus domain can quantify changes related to obstruction to outflow and may serve as adjunct measures for confirming a diagnosis EGJ outflow obstruction. (J Neurogastroenterol Motil 2022;28:62-68)