• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.63-70
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• 1984

The terrestrial UV flux rapidly increased in late spring, as measured by the chemical actinometry at two elevations (near sea level and 1,100m above sea level) on Jeju Island. More intense UV fluxes were observed at higher altitudes. Any harmful effects of solar UV-B on the growth of soybean were not detected in UV-B-exclusion experiment. To ascertain the effect of UV radiation on vegetative growth, intact (㏖ wt 124000) and large (${\sim}120000$) phytochromes were irradiated with UV-B radiation. In intact phytochrome, the Pfr form accounts for 60% of the total phytochrome under stationary state conditions, whereas it accounts for 50% in large phytochrome. Calculated quantum yields for the forward and the backward phototransformations of phytochrome by UV were ${\phi}r=0.016$ and ${\phi}fr=0.010$ in intact phytochrome, and ${\phi}r={\phi}fr=0.012$ in large phytochrome, respectively.

• Journal of Life Science
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• v.24 no.7
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• pp.757-761
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• 2014

Olive flounder (Paralichthys olivaceus) is an important aquaculture fish species in Jeju Island, South Korea. Due to the intensification of flounder fish farming, huge amounts of chemical antibiotics are used against several fish diseases. This has many harmful side effects on fish, as well as human consumers. Hence, an alternative to chemical antibiotic agents is needed for disease control. In this study, three strains of rhizobacteria (BRH433-2, TRH415-2, and THJ609-3) were isolated from the rhizosphere of plants. Assays of their antibacterial activity against fish pathogens, such as S. iniae, S. parauberis, V. anguillarum, and E. tarda, were performed with untreated broth culture (without cell separation), supernatant, and precipitated pellets separated by centrifugation. Among these, the cell suspension prepared from the precipitated pellet showed significant antimicrobial activity when compared with that of the untreated broth culture and centrifugal supernatant. These results indicate that the three isolated rhizobacterial strains exhibit antibacterial activity. Analysis of the 16S rDNA sequences of the BRH-433-2, THJ609-3, and TRH415-2 strains showed the highest similarity to Burkholderia gladioli (99.5%), Pseudomonas baetica (97.7%), and P. koreensis and P. baetica (98.4%), respectively. We suggest that the strains hold promise in disease management of fish.

• Korean Journal of Health Education and Promotion
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• v.1 no.1
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• pp.37-56
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• 1983

It is well known that smoking habit is hazardous to health, especially for juvenile. The present study on smoking behavior of high school students in Seoul has two major objectives. The first objective is to find out the smoking behavior of high school students in Seoul. Toward this objective, individual's smoking experience has been examined as ever smoking and never smoking. The second objective is to determine the variables associated with their smoking behavior at the individual, family and school environment levels. For the data collection, the survey was carried out for the four high schools in Seoul from September 15 through October 15, 1982. The major findings are summarized as follows: 1. Smoking behavior of the students 1) Out of 1,278 respondents, 30.2% of them were found to be current smokers and 29.3% of them were former smokers. This implies that around 60% of school students in Seoul have experienced smoking. 2) A significant differences in the current smoking rates between two types of the school students were shown as 19.3% for day-time school and 42% for night-time school. 3) In terms of the current smoking behavior, the students who don't live with parents were higher in smoking rate than those of the living with parents. 2. Attitudes and knowledge about smoking 1) Attitudes of students toward smoking in high school days were shown that around 17% of them agreed with it and around 64% of them disagreed with it. 2) Around 99% of the respondents answered that their smoking is harmful for health. A source of the information about negative effects of smoking on health was 'Radio and TV' (23.9%) as the most influential, 'school teacher' (20.9%), 'Newspaper' (18.2%) and so on. 3. Behavioral analysis for the current smokers 1) The factors affected for motivation in the first smoking were 'curiosity' (59.7%), 'temptation of friend' (19.7%), 'resistance feeling, (7.1%), 'merely interest and pleasure' (6%) respectively. 2) The time of the first smoking was 'third grade of Junior-high school' (31.5%) as highest, 'first grade of Senior-high school' (23.7%) and 'second grade of Junior-high school' (14.7%). 3) An average daily number of cigarettes consuming of current smokers was seven cigarettes. 4. Family and school-mates influences on individual's smoking behavior 1) The data revealed a significant relationship between student's smoking and their parent's smoking behavior. Around 75% of the students whom both parents are smoking have experienced cigarette smoking. It was found that the individual's smoking behavior was influenced by his sibling. Around 65% of the students whom brothers are smoking have experienced cigarette smoking. 2) The 'Smoking-Index' of friendship network or a group explained individual's smoking behavior in the group. The result of dyad analysis of smoking behavior in the friendship network showed that a high score of 'Smoking-Index' tended to be explained an adoption of smoking behavior at the individual level in the group. on the other hand, a low score of 'Smoking-Index' explained non-smoking behavior in the group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1009-1016
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• 2014

This study investigated the probiotic and functional characteristics of Mukeunji starter, Lactobacillus curvatus ML17, isolated from Mukeunji. Lb. curvatus ML17 was confirmed as a safe microorganism due to its non-hemolytic activity and non-production of harmful ${\beta}$-glucuronidase and ${\beta}$-glucosidase. Tolerance to artificial gastric and bile juice of Lb. curvatus ML17 was investigated. After incubation in artificial gastric and bile juice, the number of surviving cells was $1.38{\times}10^8$ CFU/mL. According to the results of adhesion assay, this strain also exhibited good adhesion to Caco-2 cells. Lb. curvatus ML17 showed good antimicrobial activity against food borne pathogens, especially Micrococcus luteus, Bacillus cereus, Salmonella enterica subsp. enterica, and Pseudomonas aeruginosa. Cell-free extract of Lb. curvatus ML17 exhibited high levels of DPPH scavenging capacity and inhibitory effects on growth of AGS human gastric adenocarcinoma cells and HT-29 human colon carcinoma cells. These results suggest that Lb. curvatus ML17 has potential for application in functional foods.

• Child Health Nursing Research
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• v.20 no.2
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• pp.113-122
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• 2014

Purpose: Purposes of this study were to identify the level of parental fever phobia and to investigate the relationship between level of parental concern about fever and related variables. Methods: Participants were 151 parents of children who visited a pediatric outpatient clinic. A selfreported structured questionnaire was used for data collection and data were analyzed using descriptive statistics and ${\chi}^2$-test. Results: Almost half of participants defined a minimum temperature for fever as $37.8^{\circ}C$ and a minimum temperature for high fever as $38.9^{\circ}C$. About 75% of participants identified harmful effects of fever as seizure and brain damage, were 'very worried' about fever, measured their child's temperature every hour or less, provided tepid massage and woke children to give antipyretics during febrile illness. There were significant relationships between level of parental concerns about fever and prior experience of febrile seizures, and/or being parents of a single child. Conclusion: Results indicate that fever phobia is prevalent among parents. Further studies are needed to develop and evaluate childhood fever management educational programs for parents. Considering health care providers as a primary information resource about fever management, health care providers should play a vital role to reduce parental unrealistic concerns about fever.

• Restorative Dentistry and Endodontics
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• v.31 no.5
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• pp.359-370
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• 2006

The objective of this study was to investigate the effect of excessive occlusal loading on stress distribution on four type of cervical lesion, using a three dimensional finite element analysis (3D FEA). The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. Four different lesion configurations representative of the various types observed clinically for teeth were studied. A static point load of 500N was applied to the buccal and lingual cusp (Load A and B). The principal stresses in lesion apex, and vertical sectioned margin of cervical wall were analyzed. The results were as follows 1. The patterns of stress distribution were similar but the magnitude was different in four types of lesion 2. The peak stress was observed at mesial corner and also stresses concentrated at lesion apex. 3. The compressive stress under load A and the tensile stress under load B were dominant stress. 4. Under the load, lesion can be increased and harmful to tooth structure unless restored.

• Journal of dental hygiene science
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• v.18 no.4
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• pp.265-270
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• 2018

The purpose of this study was to investigate the chemical properties of some commercially available mouthwashes and to ascertain whether the mouthwashes accelerated mineral loss in dental enamel. Five commercially available mouthwashes were selected from the three largest malls in Korea: Perio Total 7 Aqua Cool Mint Strong $Fresh^{TM}$ (PS; LG Household & Health Care Ltd.), Garglin $Original^{TM}$ (Dong-A Pharmaceutical Co., Ltd.), Garglin $Zero^{TM}$ (Dong-A Pharmaceutical Co., Ltd.), Listerine Naturals $Citrus^{TM}$ (LC; IDS Manufacturing Ltd.), and Listerine Cool $Mint^{TM}$ (LM; IDS Manufacturing Ltd.). The composition, pH, and titratable acidity of the mouthwashes were investigated. Six bovine teeth specimens were prepared for each mouthwash group. Each of the six specimens was individually immersed in 30 ml aliquots of mouthwash for 1 minute, 30 minutes, 90 minutes, and 120 minutes, and the samples were placed in a $36.5^{\circ}C$ stirred incubator. The degree of mineral loss (${\Delta}F$) of the tooth surface area exposed to mouthwash, compared with normal teeth, was analyzed by quantitative light-induced fluorescence-digital. The difference in ${\Delta}F$ among mouthwash groups was examined by the Kruskal-Wallis H test (${\alpha}=0.05$). The contents of mouthwashes differed between Listerine and other products, and the pH ranged from 4.09 to 6.75. The titratable acidity of PS was the lowest at 0.63 ml and highest at 9.25 ml for LM. Minor mineral loss was observed when dental specimens were immersed in the Listerine products (LC and LM) for more than 90 minutes, but the degree of mineral loss for Listerine products was not statistically significantly different from that for groups without mineral loss. In conclusion, all five commercially available mouthwashes showed no harmful effects on tooth enamel.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.194-200
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• 1992

In order to use organic resource like a compost 44 samples of paper mill sludge were collected from each paper manufacturer. Some metal and PCBs(polychlorinated biphenyls) contents in/on sludge were investigated and metal contents of soil treated with kraft and paper board sludge were checked in contrast io the non-treated soil. The staple results were the same as followings. 1. Average contents of Pb in sludge ranged 14.5-25.7 ppm, and Al, Cd, Cu, Fe, Zn were similar concentration to unpolluted soil. Also, Cr and Hg were not detected from any sludge sample. 2. PCBs contents in sludge of kraft, paper board and news print paper were determined. Less than 10 ppb of $PCB_s$ contents were detected from kraft and paper board sludges, but a little more was found in sludge of news print paper. 3. Some metal contents in sludge treated soil were much similar to non-treated soil and the concentration also were ranged under the average of unpolluted natural soil. 4. From these results paper mill sludge seemed to be no harmful effects to soil.

• Korean Journal of Social Welfare
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• v.53
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• pp.7-29
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• 2003

This study estimates the effect of economic loss including parental job loss and income loss on adolescents' educational attainment before and after family income and poverty are controlled for. Results from this study show that both parental job loss and income loss are negatively associated with the number of schooling years completed by adolescents and the probability that adolescents would enter a college. The negative relationship between economic loss and adolescents' educational attainment persists after income levels are controlled for. Income levels also have a statistically significant effect on adolescents' educational attainment. Among the various measures of income levels, poverty has an especially larger effect. Although the results are not consistent across estimated models, the effects of parental job loss and income loss are as large as that of poverty. Results for the models separately estimated by the sex of adolescents show that female adolescents are more negatively affected by both economic toss and income levels. There is little evidence that male adolescents are negatively affected by economic loss. Yet, male adolescents are negatively affected by income levels including poverty. Findings from this study suggest that societal support for families experiencing economic loss should be improved to avoid the harmful effect of the loss on adolescents' educational attainment. More targeted efforts should be made to financially support families facing both economic loss and poverty.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.2
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• pp.212-234
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• 1999

Dental restorative materials must have the physical properties to withstand wear and corrosion. Base metal alloys possess better mechanical properties and lower price than the gold alloys. For these reasons such alloys have largely replaced the precious metal alloys. One aspect to con-sider is the release of metal substances to oral environment. The release of elements from dental alloys is a continuing concern because the elements may have the potentially harmful biological effects on local tissues. The purpose of this study was to minimize metal release on the nonprecious metal surfaces by ion beam assisted deposition(IBAD) of titanium nitride (TiN) Ni-Cr-Be alloys with and without TiN coatings were secured in an wear test machine opposing ruby ball to determine their relative resistance to wear with loom, 200m, 300m and 400m sliding distance. And the corrosion behavior of the Ni-Cr-Be alloys with and without TiN coatings and 3 dental noble alloys have been studied. Potentiodynamic curves were used to analyse the corrosion characteristics of the alloys. The measurement of the released Ni and Cr ions was conducted by analysis of the electrolyte solution with atomic absorption spectroscopy. The results were as follows : 1. The critical sliding distance that wore down TiN coatings of $2.5{\mu}m$ thickness in this study condition was 300m. 2. Ion beam assisted deposition of TiN showed a good surface modification with respect to the properties of wear and corrosion resistance. 3. X-ray diffraction showed that the strongest peak of TiN is TiN(111) in the coatings. 4. The release of Ni and Cr ions from alloys measured by means of atomic absorption spectroscopy was reduced by ion beam assisted deposition of TiN.