• Journal of Korean Society of Environmental Engineers
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• v.34 no.2
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• pp.109-118
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• 2012

This study achieves results from 22 maternity breast milk samples in total to demonstrate exposure level and risk assessment of PBDEs in Seoul area. PBDEs were detected in all the breast milk samples of the present study, indicating that general population in these Seoul area are widely exposed to these chemicals. Residue levels of total PBDEs (sum PBDEs from tri- to hepta-BDE) ranged of 0.84~13.1 ng/g lipid with an arithmetic mean and median of 3.56 ng/g lipid and 2.6 ng/g lipid, respectively. Global comparison shows that the levels of total PBDEs were relatively similar to those of China, Taiwan and European country (Sweden), and somewhat higher than those in some Asian (Vietnam, Philippines, and Indonesia). In the present study, however, the levels of total PBDEs in human milk are still one to two orders of magnitude lower than those in North America. Contribution rate of each congener appeared to be predominant with BDE-47, followed by BDE-153, BDE-100, BDE-99, BDE-154 and BDE-183. The sum of BDE-47 and BDE-153 accounted for more than 65% of total PBDEs in most samples. From the result of the human risk assessment of infants for total PBDEs and BDE-47 by breast milk feeding, we could find out that the average daily doses and hazard index (95th percentile) were 16.5 ng/kg bw/day and $1.2{\times}10^{-1}$ each other when nursing for 6 months after infants born. However, it was concluded that the infant health hardly had adverse seriously effects under this research condition.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.218-228
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• 2010

Components of dental resin-based restorative materials are reported to leach from the filling materials even after polymerization. Hydroquinone (HQ) is one of the major monomers used in the dental resin and is known as a carcinogen. Thus, carcinogenic risk of HQ leaching from the dental resin becomes a public health concern. The present study attempted to examine the carcinogenic potentials of HQ on the human epithelial cell, which is the target cell origin of the most of oral cancers. Cytotoxicity of HQ was observed above 50${\mu}M$ as measured by LDH assay, indicating a relatively low toxicity of this substance in human epithelial cells. The parameters of neoplastic cellular transformation such as cell saturation density, soft agar colony formation and cell aggregation were analyzed to examine the carcinogenic potential of HQ. The study showed that 2-week exposure of HQ showed the tendency of increase in the saturation density and the significant enhancement of soft agar colony formation at the highest dose, 50 ${\mu}M$ only. It is suggested that HQ has a weak potential of carcinogenicity. When cells were treated with HQ and TPA, a well-known tumor promoter, the parameters of neoplastic cellular transformation was significantly increased. This result indicates that the potential risk of carcinogenicity from HQ is largely dependent upon the presence of promoter. Exposure of 50 ${\mu}M$ HQ increased the time-dependent apoptosis as measured by the ELISA kit. This concentration coincides with a dose of neoplastic transformation, indicating a possible link between apoptosis and HQ-induced cellular transformation. Hydroquinone generated Reactive Oxygen Species (ROS) which was evidenced by the treatment of antioxidants such as trolox and N-acetyl cysteine and the GSH depleting agent, BSO. Antioxidants blocked the generation of ROS and the GSH depleting agent, BSO dramatically increased the ROS production. Since HQ is known to increase ROS production thru activation of transcriptional factor such as c-Myb and Pim-1, it is speculated that ROS generation by HQ plays a role in the activation of oncogene, which may lead to neoplastic transformation. In addition, ROS is involved in the alteration of signal transduction, which regulates the apoptosis in many cellular systems. Thus, ROS-mediated apoptosis may be involved in the HQ-induced carcinogenic processes. Protein kinase C (PKC) is known to play pivotal roles in neoplastic transformation of cells and its high expression is often found in a variety of types of tumors including oral cancer. PKC translocation of PKC-${\alpha}$ was observed following HQ exposure. Altered signaling system may also play a role in the transformation process. Taken together, HQ leached from the dental resin does not pose a significant threat as a cancer causing agent, but its carcinogenic potential can be significantly elevated in the presence of promoter. The mechanism of HQ-induced carcinogenesis involved ROS generation, apoptosis and altered signaling pathway. The present study will provide a valuable data to estimate the potential risk of HQ as a carcinogen and understand mechanism of HQ-induced carcinogenesis in human epithelial cells.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.152-160
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• 2010

The purpose of this study was to investigate the effects of aging process on the immunity in human subjects. In this investigation, nineteen families of three generations (daughters on college age, their mothers, and grandmothers) participated to avoid genetic variation among individuals. Dietary food records, anthropometric measurements and biochemical assessments of serum nutrients were used to evaluate the nutritional status of subjects. The immune parameters of subjects were assessed by the total and differential WBC count. Total B and T lymphocytes, and T cell subsets were quantified by flowcytometer. Serum immunoglobulin G, A, M concentrations were also measured as an index of humoral immunity. The result of this study can be summarized as follows: 1. Along with the aging process, body fat was found to be increased whereas lean body mass and total body water were diminished. Since there were no significant difference in serum vitamin E levels in all age groups, serum retinal concentrations tended to decrease as one gets old. 2. Although total number of T lymphocytes seemed to be unchanged, B lymphocytes and NK cell numbers were increased by aging. The Percentage of CD8 + lymphocytes was lower in the elderly subjects compared with the younger, resulting in higher ratio of CD4 +/CD8 + lymphocytes in the elderly. Serum Ig G and Ig A levels remained unchanged, but IgM levels were significantly decreased as the age processes continue. Taking all together, it could be suggested that the alteration of immune cell population by aging is selective and possibly nonage factors such as nutrition may be attributable to the change of immunity in the elderly. The nutritional status and aging process may selectively affect both the cell-mediated (CD8 +, CD4 + CD8 + ratio, NK cell) and humoral (B lymphocyte, Immunoglobulin M, G) immune parameters in human subjects.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.269-278
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• 2016

In searching for novel agents for skin anti-aging from natural resources, we found that the extract of the fruiting bodies of Ramaria formosa (R. formosa) had significant antioxidant and human neutrophil elastase (HNE) inhibitory activities. R. formosa extract exhibited a considerable DPPH radical scavenging activity with an antioxidant content of 117.0mg/mL (ascorbic acid equivalents) at the concentration of $500{\mu}g/mL$. The capacity of R. formosa extract to scavenge peroxy radicals measured by ORAC assay also showed dose-dependent antioxidant effect with $ORAC_{Roo}$ (trolox equivalents, $1{\mu}M$) values of 0.8, 5.2, and 7.8 at the concentrations of 1, 10, and $20{\mu}g/mL$. The cellular antioxidant capacity of R. formosa extract was investigated by assaying the cellular fluorescence intensity using dichlorodihydrofluorescein (DCF). The cellular oxidative stress induced by AAPH, $Cu^{2+}$ or $H_2O_2$ in HepG2 cells was significantly attenuated by more than 30% at $20{\mu}g/mL$ of R. formosa extract. HNE activity was reduced by treatment with R. formosa extract in a dose-dependent manner, and the $ED_{50}$ value for the ethanol extract of R. formosa was $42.9{\mu}g/mL$. R. formosa extract did not exhibited antimicrobial activity against four microorganisms including Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), Candida albicans (C. albicans), Aspergillus oryzae (A. oryzae). Furthermore, the extract did not affect the inflammatory cytokine production of interleukin-10 and interferon-${\gamma}$ in NK92 cells. From the above results, we found that R. formosa extract has considerable antioxidant and elastase inhibitory effects, and does not stimulate immune cells. These findings suggest that R. formosa extract may be used as a bioactive component in cosmetic composition.

• Journal of dental hygiene science
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• v.15 no.5
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• pp.650-658
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• 2015

The purpose of this study was to determine the effects of dental hygienists' leader-member exchange (LMX) and empowerment on organizational performance, improve human resource management in their organization and their job satisfaction and organizational commitment, and provide basic data that could help improve organizational performance. A survey was conducted in 324 dental hygienists at dental care institutions in Ulsan, Busan, and Daegu from March 2 to 31, 2015 and the following results were obtained: Dental hygienists at dental hospitals had higher levels of LMX than those at dental clinics; those who were at higher positions, who were older, and who were more educated showed higher levels of empowerment. There was significant, positive correlation between LMX and empowerment and job satisfaction and organizational commitment: dental hygienists with better LMX and higher levels of empowerment showed higher levels of job satisfaction and organizational commitment. For dental hygienists, significance (${\beta}=0.325$, p<0.001) exerted the greatest impact on job satisfaction, followed by organizational commitment (${\beta}=0.264$, p<0.001) and competence (${\beta}=0.164$, p<0.01) and LMX (${\beta}=0.321$, p<0.001) had the greatest impact on organizational commitment, followed by job satisfaction (${\beta}=0.275$, p<0.001) and significance (${\beta}=0.210$, p<0.001).To put the results together, dental hygienists in dental care practice had their job satisfaction and organizational commitment affected by LMX and empowerment; therefore, it is necessary to develop diverse education programs with the objective of promoting mutual exchange between a manager of dental hygienists' team and members and improving empowerment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.110-115
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• 2011

Shelf-life of brined baechu cabbage was extended by pasteurization at $65^{\circ}C$ for 30 min. Starters (Leu. citreum and Lab. plantarum) were added to the pasteurized brined cabbage to supply beneficial lactic acid bacteria during kimchi fermentation. Control kimchis made with baechu cabbage without pasteurization and no addition of the starters to the pasteurized cabbage kimchi were also prepared. The fermentation characteristics and health functionalities of DPPH free radical scavenging activities and in vitro anticancer effects in AGS human gastric cancer cells were compared. The pasteurized brined cabbage could not be fermented well and the functionalities were also low; however, the addition of starter(s), especially mixed starters of Leu. citreum and Lab. plantarum to the pasteurized brined cabbage, significantly increased the counts of lactic acid bacteria, hardness (texture) and overall acceptability in sensory evaluation. The free radical scavenging activities and the anticancer effects were also increased. The fermentation patterns of starter added kimchi prepared with pasteurized brined cabbage were similar to those of naturally fermented kimchi. It seemed that growth of lactic acid bacteria during kimchi fermentation contributed to increased taste and health functionality of kimchi.

• Korean Journal of Childcare and Education
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• v.6 no.1
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• pp.157-176
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• 2010

The purpose of this study was to estimate the effect of "The unsafe food program" designed for improving children's biased eating habits coming from defenceless exposure to the instant food, fast food and adulterated food with MSG and artificial additives with analyzing the current condition of children's biased eating habits and preference for the unsafe foods. This program was performed for 5 year old children who was attending the kindergarten run by the author every day for two months. "The unsafe food program" consisted of the surveys on the parents' attitude towards food and health and children's eating habits, and of programs that was designed to attract children's attention to their daily food intake and to provide physical fitness, information about differences between wholesome food and junk food, and junk food's bad impacts on human body for children. In order to see the changes of children's body through this program, two physical examinations was preformed: SH pharmaceutical company's hair test to measure the accumulation level of toxic metal in children's hair and children's nutrition level before starting the program, and Ilsan Health Center's 'INBODY' test to analyze children's body composition such as body weight, skeletal muscle mass, body fat mass, BMI, body fat percentage and so on before and after the program. The results from this program follow as below. First, the unsafe foods were excluded from children's diet after parents came to recognize the negative effects of the unsafe foods. Second, children became highly interested in their daily diet through the course of gathering information by themselves and discussions together while testing and analyzing foods, and children demonstrated more self-restraint on fast food and instant food. Third, children's body constitution turned out to be improved by physical fitness in addition to this program. Fourth, children formed a good habit of eating well-balanced diet consisting of vegetables, staple food and fruits through this program designed to improve children's biased eating habits. From the results of this study it was confirmed that "the unsafe food project" had effects on improving children's eating habits.

• Journal of the Korean Society of Food Culture
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• v.20 no.1
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• pp.113-122
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• 2005

This study was designed to investigates the effects of Korean pueraris radix water extract in Al(Aluminum) administered rats. Forty-eight male Sprague-Dawley rats weighing $100{\pm}10g$ were used for this experiment and divided into following 6 groups; control group, 3% pueraria radix in water extract group, 1000 and 2000ppm Al group, 1000 and 2000ppm Al group with 3% pueraria radix in water extract group. The Al administered rats were given 1000 and 2000 ppm of $Al_2(SO_4)_3$ disoved in the distilled water. The Al content in the rats tissue of Al administered group was lower than in the rats tissue of Al group with 3% pueraria radix in water extract group. Plasma levels of renin and aldosterone activity was increased by Al administration group, compared with 3% pueraria radix in water extract group and Al administred group. Glutamate oxaloacetate transaminase(GOT) and Glutamate pyruvate transaminase(GPT) were increased in Al-administered group and lower in the 3% extracts of pueraria radix in water extract group. Lactate dehydrogenase(LDH) was lower in the 3% extracts of pueraria radix-Al group than in the Al group. This results suggested that pueraria radix in water extract group has a lowering effects on the accumulation of Al and it is belived that the pueraria radix in extracted water group has some protective effects to Al administered in rats, but the mechanism of these effects was obscure.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.583-594
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• 2007

The purpose of this study was to conduct a survey on the senses that preliminary dental hygienists have on employment, who applied for the National Dental Hygienist Examination, so that it could provide a basic reference required for fostering good human resources specializing in oral health with a sense of mission and responsibility as professional. To meet these goals, a self-administered questionnaire survey was conducted for participants in a refresher education meeting for preliminary dental hygienists across three major regions(Seoul, Daejeon and Busan), which was held by the Korean Dental Hygienists Association(KDHA) on Jan. 15, 2006. Total 289 sheets of questionnaire were collected, and 262 sheets except invalid or incomplete ones were used for examination and analysis. As a result, this study came to the following conclusions: First, it was found that 40.4% respondents wanted to be employed in dental clinic or hospital. Most respondents(90.1%) answered that faithfulness is most valued as prerequisite qualification for employment in hospital, and highest percentage of respondents(39.3%) wanted to earn 16 to 17 million Korean won annually. For internship opportunities, 61.9% respondents replied that they could willingly accept the internship, provided that basic pay and switchover to regular employee are all assured. Second, as the results of survey on employment circumstances around respondents, it was found that most respondents(58.3%) were employed in dental clinic or hospital, and highest percentage of respondents(35.0%) earned 15 to 16 million Korean won. Third, it was found that interpersonal relationships among employees had most significant effects(4.81) on selection of employment, which was followed by in-house welfare benefits 1(monthly/annual vacation, resting room, etc; 4.56). For possible influential factors on the selection of employment depending on whether employed or not, it was found that there were Significant differences in pay, welfare benefit 2(seminar, orientation, refresher training opportunities, etc), post-wedding continued employment and merit system between employees and non-employees(pE0.05). Fourth, the survey on respondents' occupational senses of dental hygienist showed that major tasks of dental hygienists were represented by oral disease prevention(92.6%), case management(71.5%), oral health education(66.3%), hospital/clinic management and dental management support(10.4%) and public oral health activities(6.7%) respectively. For job satisfaction, it was found that almost half respondents(48.9%) showed satisfaction at their job and 32.6% felt satisfied at and proud of their job. That is, majority of respondents(81.5%) felt satisfied at their job as dental hygienist. For follow-up requirements to qualify for dental hygienists, it was found that 73.3% felt it necessary to give more investments to self-development, 62.2% respondents considered protection of membership's rights as one of future assignments that KDHA should be more committed to. For future social awareness about dental hygienists as occupation, 69.2% respondents expected that they would be better developed and treated as professional. And desired training courses as a part of qualification for professional dental hygienists were represented by case management(services, manners, etc; 33.3%), implant(28.9%), esthetics(correction, prosthesis, whitening; 18.9%) and so on. For an item on working years, it was noted that 75.9% respondents would keep working as dental hygienists as long as they could.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.197-205
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• 2019

This study was to compare arterial stiffness and hemodynamic responses between male smokers and non-smokers. This study also investigates the influences of smoking before exercise on arterial stiffness and hemodynamic responses. 24 male subjects of age 20-29 without history of cardiorespiratory disease were divided into smokers and non-smokers. Smokers had more than 5 years of smoking experience. In order to evaluate the effects of pre-exercise smoking, smokers were tested twice, once with a cigarette before the exercise and the other once without one. Data was collected from bio-impedance analysis, SphygmoCor XCEL, graded exercise test, and fitness test. Main results of this study are as follows: First, there are differences between smokers and non-smokers in cardiorespiratory and hemodynamic response functions, as shown by maximal oxygen consumption, exercise duration, and heart rate. Second, the although the arterial stiffness between smokers and non-smokers showed statistically significant differences in the speed of the pulse wave velocity and augmentation index, smoker had a faster rate. It shows that smoking behavior has a negative impact on the cardiovascular system. Third, pre-exercise smoking behavior does have an impact on cardiorespiratory and hemodynamic response functions, as shown by exercise duration and heart rate. Lastly, arterial stiffness between smokers and non-smokers showed statistically not significant in the speed of the pulse wave velocity and augmentation index. However, the difference was not statistically significant. Brachial systolic pressure, a component of pulse wave analysis, on the other hand, was significantly dependent on pre-exercise smoking behavior. Subjects who participated in this study are college students in early 20s. Given their relatively short history of smoking, it is possible that their smoking habits are not severe enough to develop into cardiorespiratory or cardiovascular diseases. But Smokers showed lower levels of cardiopulmonary functions, as maximal oxygen consumption and exercise duration than nonsmokers.