• Title/Summary/Keyword: Yeon Ju Hwan

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Characterization of ptsHI Operon from Leuconostoc mesenteroides SY1, a Strain Isolated from Kimchi

  • Park Jae-Yong;Jeong Seon-Ju;Chun Ji-Yeon;Lee Jong-Hoon;Chung Dae-Kyun;Kim Jeong-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.16 no.6
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    • pp.988-992
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    • 2006
  • The ptsHI operon from Leuconostoc mesenteroides ssp. mesenteroides SY1 (L. mesenteroides SY1), a strain isolated from kimchi, was cloned and characterized. The ptsH open reading frame (ORF) was 273 bp in size, which can encode a protein of 90 amino acid residues with a molecular weight of 9,212 Da. The pfsI ORF was 1,719 bp in size, which was capable of encoding a protein of 572 amino acids with a molecular mass of 62,549 Da. ptsH and pfsI genes were transcribed as a single transcript of 2.0 kb in size regardless of carbon sources, supporting the operon structure. Although the deduced amino acid sequences of the HPr and EI were highly homologous with those of other Gram-positive bacteria, an additional amino acid (glutamine at the $3^{rd}$ amino acid) was present in HPr from L. mesenteroides SY1. Phosphorylation sites of HPr included the histidine residue ($16^{th}$) and serine residue ($47^{th}$). Mutant HPrs, in which each phosphorylation site was mutated into alanine, were obtained, and phosphorylation with HPr and mutated HPrs showed that HPr was phosphorylated at the serine residue ($47^{th}$) by HPr kinaseiphosphorylase (HPr K/P).

A Study on Algorithm of Emotion Analysis using EEG and HRV (뇌전도와 심박변이를 이용한 감성 분석 알고리즘에 대한 연구)

  • Chon, Ki-Hwan;Oh, Ju-Young;Park, Sun-Hee;Jeong, Yeon-Man;Yang, Dong-Il
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.10
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    • pp.105-112
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    • 2010
  • In this paper, the bio-signals, such as EEG, ECG were measured with a sensor and their characters were drawn out and analyzed. With results from the analysis, four emotion of rest, concentration, tension and depression were inferred. In order to assess one's emotion, the characteristic vectors were drawn out by applying various ways, including the frequency analysis of the bio-signals like the measured EEG and HRV. RBFN, a neural network of the complex structure of unsupervised and supervised learning, was applied to classify and infer the deducted information. Through experiments, the system suggested in this thesis showed better capability to classify and infer than other systems using a different neural network. As follow-up research tasks, the recognizance rate of the measured bio-signals should be improved. Also, the technology which can be applied to the wired or wireless sensor measuring the bio-signals more easily and to wearable computing should be developed.

K+ Ion Catalysis in Nucleophilic Displacement Reaction of Y-Substituted-Phenyl Picolinates with Potassium Ethoxide: Effect of Substituent Y on Reactivity and Transition State Structure

  • Im, Hyun-Ju;Lee, Jieun;Kim, Mi-Yeon;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1749-1753
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    • 2014
  • Pseudo-first-order rate constants ($k_{obsd}$) have been measured spectrophotometrically for the nucleophilic substitution reaction of Y-substituted-phenyl picolinates (7a-f) with potassium ethoxide (EtOK) in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. The plot of $k_{obsd}$ vs. [EtOK] curves upward while the plot of $k_{obsd}/[EtO^-]_{eq}$ vs. $[EtO^-]_{eq}$ is linear with a positive intercept in all cases. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOK}$ (i.e., the second-order rate constants for the reactions with the dissociated $EtO^-$ ion and ion-paired EtOK, respectively) has revealed that the ion-paired EtOK is more reactive than the dissociated $EtO^-$. The ${\sigma}^{\circ}$ constants result in a much better Hammett correlation than ${\sigma}^-$ constants, indicating that the reaction proceeds through a stepwise mechanism in which departure of the leaving group occurs after the rate-determining step (RDS). $K^+$ ion catalyzes the reaction by increasing the electrophilicity of the reaction center through formation of a cyclic transition state (TS). The catalytic effect decreases as the substituent Y becomes a stronger electron-withdrawing group (EWG). Development of a positive charge on the N atom of the picolinyl moiety through resonance interactions is responsible for the decreasing $K^+$ ion catalysis.

Alkali Metal Ion Catalysis in Nucleophilic Substitution Reactions of 5-Nitro-8-quinolyl Benzoate with Alkali Metal Ethoxides in Anhydrous Ethanol: Unusually High Na+ Ion Selectivity

  • Um, Ik-Hwan;Lee, Seung-Eun;Hong, Yeon-Ju;Park, Jee-Eun
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.117-121
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    • 2008
  • Pseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for nucleophilic substitution reactions of 5-nitro-8-quinolyl benzoate (5) with alkali metal ethoxides, EtO?M+ (M+ = Li+, Na+ and K+) in anhydrous ethanol (EtOH) at 25.0 0.1 C. The plots of kobsd vs. [EtO?M+] exhibit upward curvatures, while the corresponding plots for the reactions of 5 with EtO?Na+ and EtO?K+ in the presence of complexing agents, 15-crown-5-ether and 18-crown-6-ether are linear with rate retardation. The reactions of 5 with EtO?Na+ and EtO?Li+ result in significant rate enhancements on additions of Na+ClO4, indicating that the M+ ions behave as a catalyst. The dissociated EtO and ion-paired EtOM+ have been proposed to react with 5. The second-order rate constants for the reactions with EtO (kEtO) and EtOM+ (kEtOM+) have been calculated from ion-pairing treatments. The kEtO and kEtOM+ values decrease in the order kEtONa+ > kEtOK+ > kEtOLi+ > kEtO, indicating that ion-paired EtOM+ species are more reactive than the dissociated EtO ion, and Na+ ion exhibits the largest catalytic effect. The M+ ions in this study form stronger complex with the transition state than with the ground state. Coordination of the M+ ions with the O and N atoms in the leaving group of 5 has been suggested to be responsible for the catalytic effect shown by the alkali metal ions in this study.

Fabrication and Ion Irradiation Characteristics of SiC-Based Ceramics for Advanced Nuclear Energy Systems (차세대 원자력 시스템용 탄화규소계 세라믹스의 제조와 이온조사 특성 평가)

  • Kim, Weon-Ju;Kang, Seok-Min;Park, Kyeong-Hwan;Kohyama Akira;Ryu, Woo-Seog;Park, Ji-Yeon
    • Journal of the Korean Ceramic Society
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    • v.42 no.8 s.279
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    • pp.575-581
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    • 2005
  • SiC-based ceramics are considered as candidate materials for the advanced nuclear energy systems such as the generation IV reactors and the fusion reactors due to their excellent high-temperature strength and irradiation resistance. The advanced nuclear energy systems and their main components adopting ceramic composites were briefly reviewed. A novel fabrication method of $SiC_f/SiC$ composites by introducing SiC whiskers was also described. In addition, the charged-particle irradiation ($Si^{2+}$ and $H^{+}$ ion) into CVD SiC was carried out to simulate the severe environments of the advanced nuclear reactors. SiC whiskers grown in the fiber preform increased the matrix infiltration rate by more than $60\%$ compared to the conventional CVI process. The highly crystalline and pure SiC showed little degradation in hardness and elastic modulus up to a damage level of 10 dpa at $1000^{\circ}C$.

Properties of Cheonggukjang Fermented with Bacillus Strains with High Fibrinolytic Activities

  • Jeong, Woo-Ju;Lee, Ae-Ran;Chun, Ji-Yeon;Cha, Jae-Ho;Song, Young-Sun;Kim, Jeong-Hwan
    • Preventive Nutrition and Food Science
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    • v.14 no.3
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    • pp.252-259
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    • 2009
  • We previously isolated Bacillus strains with high fibrinolytic activities (FAs) from cheonggukjang prepared by traditional ways. To test their potential as starters for cheonggukjang, soybean was fermented for 72 hr at $37^{\circ}C$ with each isolate and a control lab strain: B. subtilis CH3-25 (BS3-25), B. amyloliquefaciens CH51 (BA51), B. amyloliquefaciens CH86-1 (BA86-1), and B. subtilis 168 (BS168, control, lab strain). Viable cell numbers of all cheonggukjang samples rapidly increased and reached about $10^9$ CFU/g after 6 hr. During 72 hr, the initial pH of 6.3 rapidly increased to 8.1$\sim$8.2 for cheonggukjang fermented with BS3-25 or BA86-1, and 7.3 for those with BA51 or BS168. FAs and protease activities (acid, neutral, and alkaline) rapidly increased in cheonggukjang fermented with BS3-25, BA51, or BA86-1 during the first 12 hr. On the other hand, those of cheonggukjang fermented with BS168 slightly increased during the first 36 hr. There were significant changes in acid and neutral protease activities in cheonggukjang fermented with BA51 or BA86-1 during the 24 hr. Rapid increases of $\beta$-glucosidase activity corresponded well with rapid increases of $\alpha$-amylase and $\alpha$-galactosidase activities in addition to increases in antioxidant activities and the TPCs (total phenolic contents). The highest increase in the TPCs was observed in cheonggukjang fermented with BA86-1 while the least was that fermented with BS168.

A Comparative Study between Urban and Rural Area Stroke Patients Admitted to Korean Medical Hospitals (한방병원에 입원한 도심지와 농촌지역 중풍 환자 비교 연구)

  • Ko, Seung-woo;Kim, Young-ji;Kong, Kyung-hwan;Sung, Hyun-kyung;Lee, Ju-ah;Choi, Ji-ae;Ha, Ye-jin;Go, Ho-yeon
    • The Journal of Internal Korean Medicine
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    • v.37 no.1
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    • pp.1-7
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    • 2016
  • Objectives: This study aimed to investigate the sociodemographic factors of stroke patients.Methods: Patients were hospitalized at Korean medical hospitals with cerebral hemorrhage and infarction and then discharged between September 2013 and August 2014. We investigated the patients’ general character and risk factors, then the patients were classified according to the regions where they reside.Results: The results indicated that having hypertension and diabetes mellitus as an underlying disease was more common in stroke patients from the country. No other statistical significance was noted among the indexes of any other results.Conclusions: Based on these results, hypertension, and diabetes mellitus were more important risk factors in patients from the country than they were for city residents. Further large-scale studies are needed to generalize the findings of this study.

Comparison Characteristic on Psychological Status between Genuine and Pseudo Halitosis (진성구취 및 가성구취 환자군의 심리적 특성차이에 대한 연구)

  • Jang, Seung-Won;Kim, Jin-Sung;Kang, Kyung;Kim, Ju-Yeon;Son, Ji-Yeong;Baek, Seung-Hwan;Choi, Jane;Ryu, Bong-Ha
    • The Journal of Internal Korean Medicine
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    • v.34 no.4
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    • pp.405-411
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    • 2013
  • Objectives : This study was designed to investigate the difference between genuine and pseudo halitosis about qi stagnation and stress. Methods : We recruited 63 halitosis patients who visited the halitosis clinic in the Kyung Hee University Korean Medicine Hospital from June 2012 to August 2013. We classified the halitosis patients into two groups, genuine and pseudo halitosis based on organoleptic assesment (OLT) score and evaluated the severity of self-reported halitosis using visual analog scale (VAS), amount of sulfide compounds using Halimeter, qi stagnation level using qi stagnation questionnaire and stress levels using heart rate variability (HRV) parameters. Results : Comparing the genuine halitosis group and the pseudo halitosis group, there was no significant difference in VAS of halitosis but significant difference in halimeter score. Distribution of qi stagnation and non-qi stagnation groups was significantly different between genuine and pseudo halitosis. Compared to the genuine halitosis group, the pseudo halitosis group showed a significant higher value of low frequency/high frequency ratio (LF/HF ratio). Conclusions : The result of this study suggest that there is significant difference about qi stagnation and stress level between genuine halitosis and pseudo halitosis patients, so when approaching pseudo halitosis patients, we should consider their psychological and emotional status.

Metal Ion Catalysis in Nucleophilic Substitution Reaction of 4-Nitrophenyl Picolinate with Alkali Metal Ethoxides in Anhydrous Ethanol

  • Hong, Yeon-Ju;Kim, Song-I;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2483-2487
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    • 2010
  • Pseudo-first-order rate constants ($k_{obsd}$) were measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl picolinate (6) with alkali metal ethoxides (EtOM, $M^+\;=\;K^+$, $Na^+$ and $Li^+$) in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. The plot of $k_{obsd}$ vs. [EtOM] exhibits upward curvature regardless of the nature of $M^+$ ions. However, the plot for the reaction of 6 with EtOK is linear with significantly decreased $k_{obsd}$ values when 18-crown-6-ether (18C6, a complexing agent for $K^+$ ion) is added in the reaction medium. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOM}$ (i.e., the second-order rate constant for the reaction with dissociated $EtO^-$ and ion-paired EtOM, respectively) has revealed that ion-paired EtOM is 3~17 times more reactive than dissociated $EtO^-$. The reaction has been proposed to proceed through a 5-membered cyclic transition state, in which $M^+$ ion increases the electrophilicity of the reaction site. Interestingly, $Na^+$ ion exhibits the largest catalytic effect. The presence of a nitrogen atom in the pyridine moiety of 6 has been suggested to be responsible for the high $Na^+$ ion selectivity.

A Comparative Study between fathers and mothers on the Parenting Efficacy, Knowledge of Infant-care and Sensitivity (아버지와 어머니의 부모 효능감, 양육지식 및 민감성의 비교 연구 - 영아기 자녀를 둔 부모를 대상으로 -)

  • Yee, Young-Hwan;Oh, Mi-Yeon
    • Korean Journal of Human Ecology
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    • v.9 no.3
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    • pp.47-62
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    • 2006
  • The purpose of this study is comparing parenting efficacy, knowledge of infant-care and sensitivity, The subjects of this study were 100 parents having 12-24 monthes old child in the city of Jeonju, Korea. Parenting efficacy was developed by Shin, Suk-Jae(1997) and consisting of 16 questions. The knowledge of infant-care was assessed using Knowledge of Child Development Inventory(KCDI) by Yoon Hyung Ju, which was modified by pedology Professor and 3 graduate school students in master's or doctorate courses. In addition, by using a tool made by Gwon, Mi-Gyeong(1998) centering on the literatures on infant cue in Barnard's NCAST program, the parents' sensitivity of infant cue is investigated. The statistical analysis of the collected data is done with SPSS 10.0, and frequency, percentage, average, standard deviation, t/F test and Pearson's correlation are also used. The results of this study were as following: First, mother's parenting efficacy was higher than father's. There were significant differences in parenting efficacy by eudcational level of mothers. Second, knowledge of infant-care was higher in mothers than fathers. Areas that mothers have knowledge of infant-care in the order of the lowest areas are emotional development, sociality development, physical development and cognitive development. Third, mothers reaction to infant cue is more sensitive and positive than father's. Fourth, There were positive correlations with father's parenting efficacy and knowledge of infant-care on emotional development, and paternal parenting uneasiness has negative correlations with his sociality development and emotional development.Meanwhile, There were positive correlations with mother's parenting efficacy and knowledge of infant-care on emotional development. Maternal parenting efficacy has negative correlations with her knowledge of infant-care on emotional development.

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