• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1547-1550
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• 2012

Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of benzyl 2-pyridyl carbonate $\mathbf{3}$ and $t$-butyl 2-pyridyl carbonate $\mathbf{3}$ with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Substrate $\mathbf{4}$ is much less reactive than $\mathbf{3}$ and the steric hindrance exerted by the bulky $t$-Bu group in $\mathbf{4}$ has been attributed to its decreased reactivity. The Br${\o}$nsted-type plots for the reactions of $\mathbf{3}$ and $\mathbf{4}$ are linear with ${\beta}_{nuc}=0.57$ and 0.45, respectively. Thus, the reactions have been concluded to proceed through a concerted mechanism, although the current reactions were expected to proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate $T^{\pm}$. It has been proposed that the rate of leaving-group expulsion is accelerated by the intramolecular H-bonding interaction in $T^{\pm}$ and the "push" provided by the RO group through the resonance interaction. Thus, the enhanced nucleofugality forces the reactions to proceed through a concerted mechanism. The reactivity-selectivity principle (RSP) is not applicable to the current reaction systems, since the reaction of the less reactive $\mathbf{4}$ results in a smaller ${\beta}_{nuc}$ than that of the more reactive $\mathbf{3}$. Steric hindrance exerted by the bulky $t$-Bu group in $\mathbf{4}$ has been suggested to be responsible for the failure of the RSP.

• The Journal of Korean Academic Society of Nursing Education
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• v.23 no.4
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• pp.389-397
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• 2017

Purpose: This study was conducted to examine awareness of biomedical ethics, and to identify affecting factors of the awareness of biomedical ethics in nursing students. Methods: The subjects consisted of 266 nursing students their third and fourth years of study. The data were collected from October to December, 2015 by self-report using questionnaires. Data analysis was performed using SPSS/WIN 18.0, descriptive statistics, t-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, and multiple regression analysis. Results: The mean score of the awareness of biomedical ethics was $2.81{\pm}0.22$, perception of death was $3.15{\pm}0.36$, and knowledge of brain death, organ donation, and organ transplant was $12.12{\pm}3.02$. The prediction factors of awareness of biomedical ethics were gender (${\beta}=.29$, p<.001), participation in religious activity (${\beta}=.23$, p=.015), and perception of death (${\beta}=.20$, p=.016). The explanation power was 17.1%. Conclusion: These results showed that education about biomedical ethics is necessary for nursing students, and the development of biomedical ethics educational programs should reflect affecting factors.

• BMB Reports
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• v.39 no.1
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• pp.22-25
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• 2006

The gene encoding MPB83 from Mycobacterium bovis Vallee111 chromosomal DNA was amplified by using polymerase chain reaction (PCR) technique, and the PCR product was approximately 600bp DNA segment. Using T-A cloning technique, the PCR product was cloned into pGEM-T vector and the cloning plasmid pGEM-T-83 was constructed successfully. pGEM-T-83 and pET28a(+) were digested by BamHI and EcoRI double enzymes. The purified MPB83 gene was subcloned into the expression vector pET28a(+), and the prokaryotic expression vector pET28a-83 was constructed. Plasmid containing pET28a-83 was transformed into competence Escherichia coli BL21 (DE3). The bacterium was induced by isopropyl-$\beta$-D-thiogalactopyranoside (IPTG) and its lysates were loaded directly onto sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), approximately 26 kDa exogenous protein was observed on the SDS-PAGE. The protein was analyzed using Western-blotting. The results indicated that the protein was of antigenic activity of M. bovis. The results were expected to lay foundation for further studies on the subunit vaccine and DNA vaccine of MPB83 gene in their prevention against bovine tuberculosis.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.179-186
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• 2009

The chemical composition of essential oil from the perennial herbaceous plants (Houttuynia cordata, Filipendula glaberrima, Peucedanum japonicum, and Ainsliaea acerifolia) was determined by GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents identified were $\alpha$-phellandrene (18.97%), $\gamma$-terpinene (12.32%), decanal (8.72%), 1-decanol (10.92%), decanoic acid (12.12%), and 2-undecanone (12.32%) from H. cordata, farnesol (2.83%), l-$\alpha$-terpineol (2.72%), benzenmethanol (2.03%), (Z)-3-hexen-1-ol (4.32%), and T-muurolol (2.07%) from F. glaberrima, $\alpha$-phellandrene (14.25%), endobornyl acetate (3.84%), heptanal (47.52%), octanal (2.65%), (E,E)-2,4-decadienal (2.75%), and octanoic acid (4.52%) from P. japonicum, and geyrene (9.74%), $\beta$-cubebene (11.15%), berkheyaradulen (22.32%), $\beta$-elemene (6.21%), (-)-A-selinene (4.85%), benzaldehyde (4.52%), and benzenacetaldehyde (3.40%) from A. acerifolia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.61-70
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• 2017

The aim of this study was to investigate the influence of stress coping style, relationship ability, and self-esteem on smartphone addiction in nursing students and to provide data for the development of intervention programs for smartphone addiction. The data were collected from 169 nursing students and analyzed with t-test, ANOVA and multiple regression by using SPSS 21.0 program. The smartphone addiction risk was shown to be 32%. Significant risk factors for smartphone addiction were problem focused coping style ( =-3.278, p=.031), hopeful prediction ( =.117, p=.044), circles presence ( =2.744 p=.019), motive for smartphone usage ( =-1.122 p=.003), and average daily using time ( =2.975 p=.000). These factors explained 43.6% of the variance in smartphone addiction. In conclusion, the results from this study suggest the need for the development of an intervention program for smartphone addiction, with consideration to the factors affecting smartphone addiction outlined in this study

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.723-730
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• 2011

To search for the new development of industrial application of woody plants, the chemical composition of the volatile constituents from woody plants (Evodia daniellii, Clerodendron trichotomum, Prunus padus, and Zanthoxylum ailanthoides) was determined by GC and GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents were t-ocimene from the leaves of E. daniellii, linalool from the leaves of C. trichotomum, benzaldehyde from the leaves and twigs of P. padus, ${\beta}$-thujene from the leaves of Z. ailanthoides, and 2-undecanone from the stems of Z. ailanthoides. These results suggested that the major volatile constituents of woody plants could be a useful lead compound in the development of functional materials for industrial application.

• Korean Journal of Occupational Health Nursing
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• v.28 no.4
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• pp.253-261
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• 2019

Purpose: This study aimed to identify the influence of job stress, compassion satisfaction, and resilience on depression of nurses. Methods: One hundred seventy six nurses working at one tertiary hospital in one metropolitan city were included. The data collection was conducted from September 1st to October 1st, 2018, using a structured, self-reported questionnaire. The collected data were analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression. Results: The $M{\pm}SD$ age of 170 subjects was $29.62{\pm}5.59$. Depression had significant negative correlations with compassion satisfaction (r=-.50, p<.001) and resilience (r=-.56, p<.001), and a positive correlation with job stress (r=.42, p<.001). In the multiple regression analysis, marital status (${\beta}=-.15$, p=.015), job stress (${\beta}=-.00$, p<.001) and resilience (${\beta}=-5.47$, p<.001) had a significant effect on depression. The explanatory power of the subject's marital status, leisure life, job stress, compassion satisfaction, and resilience on depression was 44.1% (F=27.62, p<.001). Conclusion: The study results showed that single status, low job stress, high resilience may decrease depression of nurses. Reducing job stress and improving resilience of nurses will virtually contribute to reduce their depression that can influence on not only nurses' health status but also their performance and qualitative caring for patients.

• Journal of Korean society of Dental Hygiene
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• v.19 no.3
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• pp.351-362
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• 2019

Objectives: The study aimed to analyze the factors affecting the maturity of dental biofilm, which was assessed with quantitative light-induced fluorescence-digital(QLF-D), in a sample of Korean older adults. Methods: This cross-sectional study included 67 participants, aged 65 years and older. All participants completed a questionnaire and tests to measure their manual dexterity and handgrip strength, which are parameters that indicate hand function abilities. To evaluate dental biofilm maturity, 804 surfaces of six index teeth were imaged using QLF-D and then quantified as ${\Delta}R$ values. All data were collected from May 25, 2017 to April 30, 2018. The independent t-test, one-way analysis of variance, and step-wise multiple linear regression were performed to analyze the factors associated with the maturity of dental biofilm (${\Delta}R$). Results: The multivariate linear regression analysis revealed that the factor most strongly related to dental biofilm maturity(${\Delta}R$) was manual dexterity (${\beta}=-0.326$), followed by handgrip strength (${\beta}=-0.303$) and use of interdental cleaning devices (${\beta}=-0.283$) (p<0.05). Conclusions: Manual dexterity, handgrip strength, and use of interdental cleaning devices are factors that can predict dental biofilm maturity in adults aged 65 years or older. Therefore, the hand function of a patient should be evaluated first, before assessing the oral hygiene status of the patient or providing him/her with oral health education, and the dental hygienist should provide differentiated oral hygiene care depending on the patient's hand function ability. Finally, dental hygienists should help older adults to recognize the importance of auxiliary oral hygiene devices such as interdental brushes and keep motivating them to use the devices more frequently.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.86-93
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• 2008

The chemical composition of the volatile constituents from the leaves and stems of endemic Acanthopanax koreanum and A. chiisanensis collected from Mt. Deokyu was determined by GC and GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents identified were ${\delta}-3-carene$ (31.34%), l-limonene (17.01 %), ${\beta}-elemene$(4.53%), trans-p-menth-2-ene-1,8-diol(3.13%), 1,8-cineole (4.73%), 1-dodecen-3-yne (2.64%) and (Z)-3,7-dimethyl-1,3,6-octatriene (3.21%) in A. koreanum, and ${\delta}-3-carene$ (14.78%), limonene (7.24%), t-ocimene (7.22%), ${\alpha}-terpinolene$ (8.76%), ${\gamma}-elemene$ (4.32%), ${\beta}-selinene$ (7.72%), veridifloral (3.25%) and dodecane (2.44%) in A. chiisanensis.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.62-70
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• 2013

The aim of this study was to analyze factors related to xerostomia in adults aged 30 years and over. The data were analyzed using the t-test, one-way ANOVA and multiple linear regression analysis in the SPSS version 12.0 program. The results were as follow. 1. The respondents who were older than 51 years old, unemployed and had less than 3 million won of average monthly income were more aware of xerostomia (p<0.05). 2. The respondents who answered poor and moderate for their general and oral health and the group with duplicate medication and comorbidity were more aware of xerostomia (p<0.05). 3. The respondents that had problems in chewing, communication, ordinary activities and complained of pain discomfort and suffered from anxiety depression were more aware of xerostomia (p<0.001). 4. The respondents that answered frequent dryness on their skin, eyes, lips, and nasal mucosa were more aware of xerostomia (p<0.001). 5. Xerostomia showed highest correlation with quality of life ($\beta$=0.436) followed by the number of medications ($\beta$=0.239), sense of entire body dryness ($\beta$=0.200), feeling of hopelessness ($\beta$=0.160) and number of oral mucosa disease symptoms ($\beta$=0.099) (p<0.05). According to the results of the study, xerostomia may cause deterioration in quality of life. Thus, it is advised to improve the patient management system among dental professions to prevent various complications caused by xerostomia and conduct regular health education on the cause and management method of xerostomia.