• Analytical Science and Technology
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• v.8 no.4
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• pp.807-814
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• 1995

Accurate measurements of ozone precursors are required to understand the process and extent of ozone formation in rural and urban areas. Nonmethane hydrocarbons (NMHCs) have been identified as important ozone precursors. Identification and quantification of NMHCs are difficult because of the large number present and the wide molecular weight range encountered in typical air samples. A major plan of the research team of the Climate and Air Quality Taiwan Station (CATs) was the measurement of atmospheric nonmethane hydrocarbons. An analytical method has been development for the analysis of the individual nonmethane hydrocarbons in ambient air at ppb (v) and subppb(v) levels. The whole ambient air samples were collected in canisters and analyzed by GC-FID with $Al_2O_3$/KCl PLOT column. Our targeted for quantitative analysis 43 compounds that may be substantial contributors to ozone formation. The retention indices and molar response factors of some commercially available $C_2{\sim}C_{10}$ hydrocarbons were determined and used to identify and quantify air samples. A quality assurance program was instituted to ensure that good measurements were made by participating in the International Nonmethane Hydrocarbon Intercomparison Experiments (NOMHICE).

• Journal of Korea Entertainment Industry Association
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• v.14 no.2
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• pp.195-203
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• 2020

Purpose: This study was a descriptive study to investigate on the effect of calling, self-efficacy, workplace bullying on retention intention among nurses in small and medium-sized hospitals. Methods: The research subjects were 224 nurses selected through convenient sampling from among those who have worked six months or longer in seven small and medium-sized hospitals located in G City. The data were collected using a structured questionnaire from July 17 to 30, 2018. The data was analyzed by descriptive statics, a t-test, ANOVA, Scheffé test, Pearson's correlation coefficient, and a stepwise multiple regression using SPSS/WIN 22.0 program. As a measuring tool, Calling was the Calling & Vocational Questionnaire (CVQ) developed by Dik, Eldrige and Steger (2008). Self-efficacy was developed by Sherer et al. (1982) and modified by Jeong Ae-soon (2007). Workplace bullying was developed by Einarsen, Raknes and Matthiesen (1994) in the Norwegian Negative Behavioral Experience Questionnaire (NAQ), and by Nam Woong et al. (2010). The retention intention was to use NRI (Nurses' Retention Index) developed by Cowin (2002) as a tool for Kim Min-jung (2006). Results: Factors affecting nurses' retention were analyzed. The analysis showed that retention intention was positively affected by self-efficacy (β=.24, p<.001), sense of calling (β=.23, p<.001) and annual wage (β=.21, p=.001) and negatively affected by workplace bullying (β=-.16, p=.008) on a statistically significant level, with an explanatory power of 28.6%.

• The Journal of the Korean dental association
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• v.22 no.11 s.186
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• pp.953-960
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• 1984

The author applied the attachment fixation overdenture on the patient whose residual alveolar ridge height was poor to increase mechanical denture retention, and observed the periodontal condition of the abutment roots after insertion of attachment fixation overdenture. The author obtained the conclusions as follows; 1. Attachment fixation overdenture showed better mechanical retention than conventional overdenture did, but it resulted unfavorable crown-root ratio. 2. Within one year after insertion, there were not significant changes in periodontal health, which was indicated by plaque index, gingival index, pocket depth, tooth mobility gingival hyperplasia and alveolar bone change. 3. Mild periodontal thickening was observed. 4. This study emphasized the importance of adequate follow-up care and home care instructions.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.283-288
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• 1995

Rapid gas chromatographic profiling method was applied to saliva from healthy subjects for the analysis of free organic acids. Saliva samples were first saturated with NaHCO$_{3}$ and extracted with diethyl ether. The aqueous phase was solid-phase extracted using Chromosorb P as the adsorbent and diethyl ether as the eluent after the acidification and NaCl saturation, followed by triethylamine treatment. The resulting tiiethylammonium salts of acids were directly converted into stable tert.-butyl-dimethylsflyl derivatives, with subsequent analysis by dual-capiuary column gas chromatography and gas chromatograpy -mass spectrometry. From the ten saliva samples studied, twenty eight free organic acids including various fatty acids, hydroxy acids, dicarboxylic acids, md aromatic acids were tentatively identified. Among the acids identified , the concentration of lactic acid was highest for five saliva samples while $\alpha$-hydroxyisocaproic acid was most abundant for me sample, and succinic acid and glycolic acid for two samples. respectively. When the GC profiles were simplified to the corresponding acid retention index spectra of bar graphical form, they presented characteristic patterns for each individual.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.211-218
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• 2006

This work deals with 24 substances composed of nitrogen-containing heterocycles. The relationships between the chromatographic retention factor (k) and those physicochemical properties which are relevant in quantitative structure-properties relationship (QSPR) studies, such as the polarizability $(\alpha)$, molar refractivity (MR), lipophilicity (logP), dipole moment $(\mu)$, total energy $(E_{tot})$, heat of formation $(\Delta H_f)$, molecular surface area $(S_M)$, and binding energy $(E_b)$, were investigated. The accuracy of the simple linear regressions between the chromatographic retention and the descriptors for all of the compounds was satisfactory (correlation coefficient, $0.8 \leq r \leq 1.0$). The QSPR models of these nitrogen-containing heterocyclic compounds could be predicted with a multiple linear regression equation having the statistical index, r = 1.000. This work demonstrated the successful application of the multiple linear approaches through the development of accurate predictive equations for retention factors in liquid chromatography.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.3
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• pp.223-230
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• 2014

Purpose: The purpose of this study was to evaluate the improvement and posttreatment stability of patients treated with extraction of lower incisors. Materials and Methods: The total of 20 patients with extracted lower incisors were analyzed by means of diagnostic models and panoramic x-rays at the time of initial, final and after 2 years of retention period of the treatment. Irregularity index, overjet, overbite, tooth size-arch length discrepancy (TSALD), intercanine width, intermolar width and American Board of Orthodontics cast/radiographic evaluation (ABO-CRE) were analyzed. Statistical analysis was performed using Wilcoxon signed-rank test. Results: After treatment, irregularity index showed significant decrease (P = 0.000). TSALD showed significant increase (P = 0.028). During retention period, irregularity index showed significant increase (P = 0.001). For ABO-CRE, total score showed significant decrease after treatment (P = 0.000) and showed average decreased which was not significant result (P = 0.053). Conclusion: Through evaluation of stability of extraction of lower incisors by means of diagnostic models and panoramic x-rays, it can be concluded that lower incisor extraction treatment had been stable for 2 years after treatment.

• Journal of Korean Medicine for Obesity Research
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• v.11 no.1
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• pp.25-34
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• 2011

Objectives The purpose of this study was to examine the characteristics of diagnostic pattern questionnaire associated with Body Mass Index in premenopausal women. Methods We studied 41 patients visiting Gangdong Kyung Hee University Hospital from 1st April 2011 to 25th May 2011. The subjects were categorized in two groups, overweight & obesity group (n=12) and low weight & normal group (n=29). We studied the difference of diagnostic pattern questionnaire scores between two groups by Independent samples T-test and correlation between diagnostic pattern questionnaire scores of overweight & obesity group by Pearson's correlation coefficient test using SPSS for windows (version 13.0). Results Blood stasis, retention of undigested food, cold pattern scores of overweight & obesity group were non-significantly higher than low weight & normal group. Heat pattern score of overweight & obesity group was significantly higher than low weight & normal group. Cold-heat, phlegm-cold, blood stasis-cold, phlegm-blood stasis, phlegm-retention of undigested food significantly showed positive correlation coefficient in overweight & obesity group. Conclusions The results suggest that obese women tend to show heat pattern. It seems to be that multiple factors such as phlegm, blood stasis, retention of undigested food are causative of obesity.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.749-754
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• 1989

The essential oil was prepared by a gas co-distillation method from flavedo of Poncirus trifoliata and was analyzed by GC/ retention index (RI) and GC/MS. The essential oil prepared by a gas co-distillation gave a whole fragrance of Poncirus trifoliata. The identification of the flavor components was performed by multi-dimensional analysis using GC/RI and GC/MS. GC/RI and GC/MS were complementary to each other. In applying GC/RI for identification, it was more effective when two columns of different polarities were used. Thirty volatile flavor constituents were identified in Poncirus trifoliata. Limonene, myrcene, ${\beta}-caryophyllene,\;trans-{\beta}-ocimene$, ${\beta}-pinene$, 3-thujene and 7-geranyloxycoumarin were the major constituents and cis-3-hexenyl acetate, n-hexyl acetate, 2-methyl acetophenone, elixene and elemicine had not been reported earlier as citrus components.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.562-568
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• 1989

The essential oils from ripe fruit peel and leaf of Zanthoxylum piperitum DC were extracted by gas co-distillation method and analyzed by gas chromatography/mass spectrometry (GC/ MS) and retention index matching. The experimental results revealed the presence of over 100 volatile components. Major components were 1,8-cineol (25.47%), limonene (11.91%), geranyl acetate (9.01%), myrcene (6.15%) in fruit peel and citronellal (23.11%), 1,8-cineol (18.38%), citronellol (6.04%) in leaf. Among the components identified were the following; in fruit peel, ${\alpha}-pinene$ and 13 hydrocarbons, linalool and 8 alcohols, citronellal and 3 aldehydes, carvone and 2 kotones, methyl salicylate and 7 esters, and 1,8-cineol and oxides, and in leaf, ${\alpha}-pinene$ and 7 hydrocarbons, linalool and 7 alcohols, citronellyl acetate and 5 esters, citronellal and 1 aldehyde, carvone, and 1,8-cineol and 1 oxide.

• The Journal of Internal Korean Medicine
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• v.40 no.3
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• pp.390-408
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• 2019

Objectives: Several pattern diagnosis questionnaires have been developed to objectify the process of pattern diagnosis in Korean medicine. In this context, this study aimed to develop a food retention questionnaire for functional dyspepsia (FRQ-FD) by modifying the previously developed food retention questionnaire (FRQ) and to verify its reliability and validity. Furthermore, this study aimed to identify the optimal cut-off value of the FRQ-FD for standardization and use in clinical situations. Methods: To develop the FRQ-FD, we extracted the major symptoms of food retention pattern for functional dyspepsia from Chinese/Korean medicine textbooks and requested an importance survey from experts using the Delphi method. The first draft of the FRQ-FD was composed of 25 questions comprising 8 questions from the textbooks and the Delphi method and 17 questions from the FRQ already developed in 2013. To analyze its reliability, validity, and optimal cut-off value, 60 subjects were enrolled in this study from June 25 to August 13, 2018. Thirty patients were diagnosed as both functional dyspepsia and food retention pattern, and 30 healthy participants were not. All participants were requested to fill up the FRQ-FD, Stomach Qi Deficiency Questionnaire (SQDQ), Scale for Stomach Qi Deficiency pattern (SSQD), visual analog scale (VAS) for dyspepsia, Nepean Dyspepsia Index-Korean version (NDI-K), and functional dyspepsia-related quality of life (FD-QoL). Results: No statistically significant differences were found in sex distribution, age, and body mass index between the patient group and the control group. As five questions affected the reliability negatively and three questions affected the clinical validity negatively, we decided to exclude the eight questions upon further investigation. The Cronbach's ${\alpha}$ coefficient of the revised FRQ-FD (17 items) was 0.899, and its clinical validity was verified. Construct validity was analyzed by factor analysis and produced five factors. Statistically significant positive correlations were found between the revised FRQ-FD and the other dyspepsia scales, namely, SQDQ, SSQD, VAS, NDI-K, and FD-QoL. VAS and NDI-K especially had strong positive correlations with FRQ-FD. Conclusions: The FRQ-FD developed in this study can provide fundamental reliability and validity for a pattern diagnosis questionnaire. FRQ-FD can help to diagnose food retention pattern in functional dyspepsia patients. Further studies are required to inspect several statistical factors.