• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.71-79
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• 1998

Objectives : This study was to evaluate sleep patterns and daytime sleepiness resulting from rotating shiftwork. The authors, also, tried to find out the relationship between the severity of daytime sleepiness and personality factors. Methods : The subjects consisted of 41 female rotating shiftwork nurses and the control group consisted of 39 female day timeworkers. All of them completed the Sleep questionnaire of Korea University Sleep Disorder Clinic, the Epworth Sleepiness Scale(ESS), the 16 Personality Factors(16PF), the Beck Depression Inventory(BDI) and the State Trait Anxiety Inventory(STAI). Multiple regression analysis of 16PF of the rotating shiftwork nurses was done to find out possible predictors of the severity of daytime sleepiness. Results : The mean duration of deprived sleep due to rotating shiftwork was $64.26\;{\pm}\;14.54\;min$. The frequency of sleep difficulty($1.24\;{\pm}\;1.17\;day/week$ vs $0.67\;{\pm}\;1.31\;day/week$, p < 0.05), time needed to fall asleep($103.05\;{\pm}\;73.48\;min$. vs $70.00\;{\pm}\;60.08\;min$, p < 0.05), sleep duration when having some difficulties in sleep ($204.25\;{\pm}\;79.90\;min$. vs $280.44\;{\pm}\;111.59\;min$., p < 0.001), recent changes in energy($x^2\;=\;4.16$, p < 0.05), worrying about sleep($x^2\;=\;11.08$, p < 0.05), and taking naps($x^2\;=\;4.98$, p < 0.05) showed significant differences between rotating shiftworkers and normal controls. The ESS socre of shiftworkers ($8.68\;{\pm}\;3.04$) was greater than that of normal controls ($6.86\;{\pm}\;3.04$)(p < 0.01). Personality factors such as C factor($R^2\;=0.283$), I factor($R^2\;=0.358$) and G factor($R^2\;=0.470$) were related with the severity of the daytime sleepiness(p < 0.001). Conclusions : The rotating shiftwork nurses had more difficulties in sleep such as having difficulties in falling asleep and in maintaining sleep, and showed lowered energy, decreased senses of well-being and so on. The rotating shiftwork nurses experienced more severe daytime sleepiness than controls did. Personality factors, such as C factor, I factor, and G factor of 16PF were suggested to be useful for predicting the severity of daytime sleepiness resulting from rotating shiftwork.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.177-184
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• 2004

Objectives : This study investigated the hypothesis that increasing light-curing time would leave the oxygen-inhibited layer (OIL) of the adhesive thinner, and in turn, result in lower shear bond strength (SBS) than those obtained by the routine curing procedures. Methods：120 human extracted posterior teeth were randomly divided into three groups for bonding with three adhesives：All Bond 2/sup (R)/, One Step/sup (R)/, and Adper Prompt/sup (R)/. They were subsequently divided into four subgourps with different light-curing time (10, 20, 30 and 60s). The assigned adhesives were applied on superficial occlusal dentin according to the manufacturer's instructions and cured with one of the four curing times. Composite resin cylinder, 2.35㎜ in diameter, were built on the cured adhesive and light-cured for 40s. SBS were measured after 24h from the bonding using a universal testing machine (crosshead speed 1.0 ㎜/min). The relative thickness of the OIL and the degree of conversion (DC) were determined from the adhesive on a slide glass using FT-NIR in an absorbance mode. Data were analysed with One-way ANOVA and Duncan's multiple test (p〈0.05), Results：With increasing cure time, although there were no significant difference in th SBS of One-step and Adper Prompt (p〉0.05), those of All Bond 2 decreased significantly (p〈0.05). The relative thicknesses of the OIL on each adhesive were not affected by the cure time (p〉0.05). Although the DC of All-Bond 2 were statistically not different with increasing cure time (p〉0.05), those of One-Step and Adper Prompt showed an increasing trends with increasing cure time (p〈0.05). Conclusions：Increasing light-curing time did not affect on the relative thickness of the OIL of the adhesives, and in turn, on the SBS to dentin.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.343-355
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• 2007

The objectives of this study was to evaluate the durability of 4 resin cements by means of microtensile bond strength test combined with thermocycling method and fractographic FE-SEM analysis. Experimental groups were prepared according to thermocycling (0, 1,000, 5,000) and the kind of resin cements, those were Variolink II, Multilink, Panavia F 2.0, Rely X Unicem. Flat dentin surfaces were created on mid-coronal dentin of extracted third molars. Then fresh dentin surface was grounded with 320-grit silicon carbide abrasive papers to create uniform smear layers. Indirect composite block (Tescera, Bisco Inc., Schaumburg, IL, USA) was fabricated ($12\;{\times}\;12\;{\times}\;6\;mm^3$). It's surface for bonding to tooth was grounded with silicon carbide abrasive papers from 180- to 600-grit serially, then sandblasted witk $20\;-\;50\;{\mu}m$ alumina oxide. According to each manufacturer's instruction, dentin surface was treated and indirect composite block was luted on it using each resin cement. For Rely X Unicem, dentin surface was not treated. The bonded tooth-resin block were stored in distilled water at $37^{\circ}C$ for 24 hours. After thermocycling, the bonded tooth-resin block was sectioned occluso-gingivally to 1.0 mm thick serial slabs using all Isomet slow-speed saw (Isomet, Buehler Ltd, Lake Bluff, IL, USA). These sectioned slabs were further sectioned to $1.0\;{\times}\;1.0\;mm^2$ composite-dentin beams. The specimens were tested with universal testing machine (EZ-Test, Shimadzu, Japan) at a crosshead speed of 1.0 mm/min with maximum load of 500 N. The data was analyzed using one-way ANOVA and Duncan's multiple comparison test at $p\;{\leq}\;0.05$ level. Within the limited results, we conclude as follows; 1. The bond strength of Variolink II was evaluated the highest among experimental groups and was significantly decreased after 1,000 thermocycling (p < 0.05). 2. The bond strength of Multilink was more affected by thermocycling than the other experimental groups and significantly decreased after 1,000 thermocycling (p < 0.05). 3. Panavia F 2.0 and Rely X Unicem showed the gradually decreased tendency of microtensile bond strength according to thermocycling but there was no significant difference (p > 0.05). 4. Adhesive based-resin cements showed lower bond strength with or without thermocycling than composite based-resin cements. 5. Variolink II & Multilink showed high bond strength and mixed failure, which was occurred with a thin layer of luting resin cement before thermocycling and gradually increased adhesive failure along the dentin surface after thermocycling. The bonding performance of resin cement can be affected by application procedure and chemical composition. Composite based-resin cement showed higher bond strength and durability than adhesive based-resin cement.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.795-807
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• 1995

This study was carried out from 1993 to 1994 in the small industries in Incheon. The objectives of this study was in order to estimate the quitting rate, to identify its relating factors and to propose effective quitting management policy in the small industries. The results were as follows ; 1. The quitting rate of 266 study workers was 42.1%(112 workers). 2. Age, working duration, position, marrital status were significant difference between the quitting group and the non - quitting group. In the quitting group, mean age was young, working duration was short, general employees and unmarried workers were many compared with the non - quitting group. 3. In the industry characteristics, total assets, total assets, sales per person, establishment duration and occupational health and safely status were significant difference between the quitting group and the non - quitting group. In the quitting group, total assets, total sales and sales per person were little, establishment duration of company was short and occupational health and safety status were poor compared with the non - quitting group. 4. In the quitting group, worker's response to employer's disposal about health and safety was more passive and the relation to employer with employee was significantly poor compared with the non - quitting group. 5. Multiple logistic regression analysis of quitting against family income per person, working duration, relation to employer with employee, occupational health and safety status in industry, worker's response to employer's disposal about health and safety and sales per person was done. Working duration, occupational health and safety status, worker's response to employer'1 disposal about health and safety were significant explainatory variables for quitting. Above results showed that the quitting rate was high and it was significant difference between the quitting group and non : quitting group according to characteristics of workers and of industries. Especially, it suggested that working duration, occupational health and safety status and worker's response to employer's disposal about health and safety were significant quitting factor. Therefore, it should be reflected in the quitting management and the policy of steady employment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.1
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• pp.1-32
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• 2003

Objectives: This study was carried out to analyze and understand the trends of research papers published In the Journal of Oriental Medical Surgery？phthalmology & Otolaryngology Society(JOMSOOS). Methods: We studied the 308 research papers that had been published in JOMSOOS from 1988 Vol. 1. No. 1. to 2002 Vol. 15. No. 2. Our study was developed through the four stages in order to analyze the papers; 1) we analyzed all the papers overall to classify them into three categories; original article. review article and case report. 2) we classified the original articles in terms of methodology. 3) we also analyzed the case reports according to the sort of disease each paper dealt with. 4) we had another statistical approach to each paper to figure out the distribution of diagnoses in detail. Results: We have got the following outcomes from our analysis of the papers in terms of the four stages. 1. Overall Analysis. 1) Classification of 308 research papers between 1988 and 2002: 137 original articles(44.48$\%$), 111 review articles(36.04$\%$), 56 case reports(18.18$\%$). 2) Used language: Korean(99.03$\%$). English(0.97$\%$). 3) The Number of Authors: 2 persons(42.86$\%$). 3 persons(29.87$\%$), 1 person(14.61$\%$). 2. Original Article Analysis 1) Classification of 137 original articles in terms of methodology: 90 experimental studies(65.69$\%$)46 descriptive studies(33.58$\%$), 1 analytic study(0.73$\%$). 2) Classification of the original articles according to the use of statistical methods: No statistical methods(36.42$\%$), Descriptive methods only(1.99$\%$), Not defined(23.18$\%$), t-test(24.50$\%$), ANOVA(3.97$\%$), Multiple comparison(2.65$\%$), Non-parametric test(2.65$\%$), Other methods(1.32$\%$). 3) Classification of 46 descriptive articles in terms of diseases: otorhinolaryngology(43.48$\%$), dermatology(23.91$\%$), ophthalmology(13.04$\%$), facial palsy(13.04$\%$). 4) Classification of descriptive articles in terms of the number of patients: the highest was 'more than 26 but less than 50 persons'(19 articles - 41.30$\%$). 5) Classification of descriptive articles in terms of the period for patients observation: the highest was the time 'more than 9 but less than 12 months(34.78$\%$)' Out of the 34.78$\%$, the number of articles with the patients observed for more than 12 months was 13(28.26$\%$). 3. Case Report Analysis 1) Classification of 56 case reports in terms of the sort of disease: dermatology(44.64$\%$), ophthalmology(19.64$\%$), otorhinolaryngology(14.29$\%$), facial palsy(8.93$\%$). 2) Classification in terms of the number of patients: 1 person(50$\%$), 3 persons(16.07$\%$), 2 persons(14.29$\%$). 4. Diagnosis Distribution of Each Disease. 1) Studies regarding ophthalmology : the percentage of 'strabismus' cases was the highest(33.33$\%$). 2) Studies regarding otorhinolaryngology : nasal inflammation(34.48$\%$), tinnitus(20.69$\%$). 3) Studies regarding dermatology: the percentage of 'allergic skin disease' was the highest(33.33$\%$). Conclusions: We analyzed the trends of research papers that have been published in JOMSOOS in detail. We came to understand the trends of the research through this study. However, we acknowledge that we only adopted the quantitative method out of various possible analysis methods. For further studies, we strongly urge to adopt the qualitative methods as well.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.191-199
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• 2016

Objectives : Despite the increased popularity of highly caffeinated beverages, there is little research examining psychiatric adverse effects. The purpose of this study was to investigate the relationships among pattern of highly caffeinated beverage intake and depressive symptom, suicidal ideation, suicidal plan, suicidal attempt in Korean adolescents. Methods : The data was obtained from the 2014 Korean Youth's Risk Behavior Web-based Study by Korea Centers for Disease Control & Prevention. All participants conducted web-based questionnaire survey. Chisquare test and multiple logistic regression analysis were performed to determine the association among highly caffeinated beverage intake pattern, depressive symptom, suicidal ideation, suicidal plan and suicidal attempt adjusting for differences in age, gender, academic achievement, socioeconomic status. Results : A total of 71,638 participants were enrolled in this study. Depressive symptom, suicidal ideation, suicidal plan and suicidal attempt were significantly more frequent in the group with presence of highly caffeinated beverage intake within 1 week than in non-drinker group(p<0.01). Highly caffeinated beverage intake was significantly associated with suicidal attempt(OR=1.99 ; 95% CI, 1.77-2.22). In addition, depressive symptom, suicidal ideation, suicidal plan and suicidal attempt were significantly more common in the group with heavy-drinker who exceed recommended daily intake dose of caffeine than in the group with light-drinker(p<0.01). Heavy drinking of caffeinated beverage was significantly associated with suicidal attempt(OR=4.05 ; 95% CI, 3.02-5.43). Conclusions : We found that highly caffeinated beverage intake was related to more frequent depressive symptom, suicidal ideation, plan, attempt in adolescents. Also, caffeine intake which exceed recommended daily intake dose identified the predictor of suicidal attempt. Our result suggested that clinicians need to be aware of the possible psychiatric adverse effects of highly caffeinated beverage in vulnerable population including young adolescents.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.1
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• pp.47-56
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• 2015

Objectives:The aim of this study is to investigate any differences between non-medical and medical college students for : 1) a level and the nature of perceived stress, 2) a level of life satisfaction, and 3) the related factors affecting to life satisfaction. Methods:We measured self-reported questionnaires of stress, satisfaction with life, health behavior including happiness, alcohol use, nicotine dependency and depressive symptoms in 1,714(863 non-medical and 851 medical) college students. Results:Non-medical college students had significantly higher total stress scores than medical college students(${\chi}^2$=7.66, p<.001). In non-medical college students, employment problem score was significantly higher than medical college students(t=4.07, p<.001). In medical college students, the scores of academic achievement (t=-3.81, p<.001), change of social life(t=-2.03, p<.05), death(t=-2.05, p<.05) or sickness(t=-2.60, p<.05) of friends were significantly higher than non-medical college students. And non-medical college students showed significantly lower life satisfaction scores than medical college students(${\chi}^2$=-19.05, p<.001). We also found that life satisfaction were significantly related to happiness in non-medical college students(${\beta}$=.410, $R^2$=.325, p<.001) and depressive symptoms in medical college students(${\beta}$=-.435, $R^2$=.326, p<.001) by stepwise multiple regression analysis. Conclusions:In this study, a level and the nature of perceived stress, a level of life satisfaction, and the related factors affecting to life satisfaction showed definitely differences between non-medical and medical college students. We suggest with our findings that specified mental health promotion program need for the college student's mental health management.

• Korean Journal of Community Nutrition
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• v.24 no.3
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• pp.232-244
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• 2019

Objectives: This study evaluated the nutritional status and prevalence of metabolic syndrome of the people who participated in the KNHANES according to the number of household members. They were assessed by using information from the 2013~2014 Korea National Health and Nutrition Examination Survey (KNHANES). Methods: A total of 6,088 persons aged 19 years and over participated in 2013~2014 KNHANES, and they were classified into three groups according to the number of household members (single-person, two-person, three-person & over). The dietary behavior, nutritional status, health-related factors and the prevalence of metabolic syndrome of the subjects were investigated with using information from the survey questionnaires of KNHANES. The nutrient intake data of the subjects were obtained by the 24-hour recall method and this was analyzed for evaluating the nutrition adequacy ratio and the index of nutritional quality. The prevalence of metabolic syndrome among the subjects, and according to the study groups, was estimated using the blood and physical measurement data of the subjects. Results: As for EQ-5D index available for all the health states generated by the EQ-5D descriptive system, the single-person household member was the lowest among all the household types. The index of nutrition quality for protein, crude fiber, calcium, phosphorus, potassium, riboflavin and vitamin C in the single-person household was lower than that of the two-person or the three-person and over households (p<0.001). The mean adequacy ratio of single-person households was significantly decreased compared with that of the other types of households (p<0.001). The prevalence of metabolic syndrome was higher in the single-person households than that in the multiple-person households (p<0.001). Conclusions: These results showed that dietary behaviors, nutrition status and health status might be influenced by the number of household members. The results from this study would be useful for improving Korean people's dietary life and health status by implementing evidence-based, specialized intervention for the members of diverse types of households.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.102-111
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• 2018

Objectives : This study aimed to investigate the relationship between personality characteristics of medical students at their admission and the level of depression, anxiety, and resilience at their third year. Methods : Self-reported questionnaires were conducted to the students at the beginning of the first year and the third year. When the students in their first year, they performed the personality assessment inventory, the Beck depression inventory, and the Beck anxiety inventory. When they were in the third year, the students answered the composite Scale of morningness and Conner-Davidson resilience scale-10 in addition to the BDI and BAI. Multiple linear regression analyses were performed to identify predictors of the level of depression, anxiety, and resilience. Results : Of the subscales of depression in the PAI, the physiological depression (${\beta}=-0.285$, p=0.049) associated with increase in the depression from the first to the third year. Among the anxiety-related disorder subscale in the PAI phobia (${\beta}=0.119$, p=0.022) and traumatic stress (${\beta}=0.375$, p=0.007) associated with the level of depression at third grade. Somatization (${\beta}=0.631$, p<0.001) in the PAI associated with the level of anxiety at third year. The anxiety (${\beta}=-0.531$, p<0.001) in the PAI was positive associated with the resilience at third grade. Conclusions : This study showed that certain personality characteristics at admission had significant relationships with the level of depression, anxiety, and resilience at the third grade medical students.

• Journal of Rhinology
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• v.25 no.2
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• pp.91-98
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• 2018

Background and Objectives: The present study evaluated the results of skin prick test using 55 allergens at 20 centers in the Republic of Korea in 2006, 2010, and 2014-2015. The aim was to assess changes in the positive rate of allergens according to temporal, regional, and environmental factors. Materials and Method: In total, 20 hospitals were selected based on the population distribution in the Republic of Korea. A skin prick test panel comprising 55 aeroallergens was distributed to 18 hospitals for this prospective study. The 2006 and 2010 skin prick test results were collected and analyzed retrospectively from 20 hospitals, while the 2014/2015 skin prick test results (from June 2014 to May 2015) were collected prospectively from 18 hospitals. Results: A total of 14,897 SPT test results were analyzed: 4,319 in 2006, 7,431 in 2010, and 1,852 in 2014/2015. The overall rate of skin prick test positivity to more than two allergens was significantly higher in males than females. The positive rates of alder pollens and birch, oak and ragweed pollen positivity were increased in older patients. Several positive rates were increased according to the temperature in spring. The positive rates for beech pollen, birch pollen, hazel pollen, oak pollen, Tyrophagus putrescentiae, mugwort, cat, Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae were significantly increased, while those of Cult rye pollen and dandelion were significantly decreased over the three test periods. The overall positive rate for allergens in Jeju province varied significantly from Seoul and other cities. Conclusion: Change in the positive rate of multiple aeroallergens was evaluated in the Republic of Korea over time. Our findings can be used to recommend aeroallergens suitable for inclusion in skin prick test panels in the Republic of Korea and will facilitate further investigation of changes in the patterns of allergic diseases.