• Journal of dental hygiene science
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• v.3 no.1
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• pp.45-50
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• 2003

In order to develop the program of oral hygiene education for elementary school senior-students, a questionnaire survey of elementary fourth, fifth and sixth students who are under continual control program of oral hygiene. (1) For tooth brushing time, after dinner is more than before. 73.7% of respondents brushed the teeth twice or more a day. (2) 62.1% of respondents took the cariogenic food twice or more a day. (3) 90.1% of respondents had visited a dental clinic. (4) Concerning fear for dental treatment, only 14.4% had a feeling of fear. (5) Regarding the experience with a preventive treatment, 39.7% had an experience with pit and fissure sealing, and 24.2% had an experience with the application of fluorides. (6) 46.2% of respondents had a preference for the fluoride mouth rinsing program, and 38.4% wanted that program to keep going on. As to the reason to favor the fluoride mouth rinsing program, 38.2% preferred it because of prevention of dental caries, and 43.0%, the largest percentage, didn't favor it because they found it too much trouble to do. (7) Comparing with the research result in 2000, we proved positively the educational effect of brushing frequency, positive understanding and preference to water school fluoridation program, and got the negative data of experience of visiting to oral clinic and preventive treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.561-570
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• 2008

This study aimed to determine the effects of freeze-dried onion powder (OP) which contains rich in quercetin (22 mg/10 g) on hyperlipidemic participants. Fourteen participants (total cholesterol level in plasma $270.8{\pm}21.4mg/dL$) $40{\sim}59$ years of age who were diagnosed as hyperlipidemia by a physician at Fatima Hospital in Changwon took part in this study for 12 weeks. We investigated the anthropometric data and dietary habit by using questionnaires. Also, blood samples were collected from the patients in fasting before and after this 12 weeks intervention study. 78.6% of the patients showed interest in health diet management and weight control; however, they also showed some problems in their dietary habit (meal irregularity, food choice, calorie nutrient balance, high fat and cholesterol etc.) and life style (smoking, eating out, alcohol intake) that could have adverse effect on hyperlipidemic therapy. Most participants (85.7%) thought that OP was good for their health. The total cholesterol and LDL-cholesterol significantly decreased with OP intake. The HDL-cholesterol increased and the Atherogenic index (AI) significantly decreased. Regarding the correlations of dietary habit and life style with anthropometric and biochemical factors, the alcohol intake level was significantly correlated with the frequency of eating out and body mass index (BMI). Exercise level showed positive correlation with HDL-cholesterol and negative correlation with atherogenic index (AI). These results suggest that the intake of polyphenol rich onion may decrease the risk of hyperlipidemia by reducing cholesterol level. We consider these hypolipidemic effects of OP as a possible functional food. However, further research such as a well designed longterm clinical study with experimental and placebo groups is needed.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.220-229
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• 2009

Strain improvement and morphology investigation in bioreactor cultures were undertaken in suspended cultures of Phellinus linteus mycelia for mass production of protein-bound polysaccharides(soluble ${\beta}$-D-glucan), a powerful immuno-stimulating agent. Phellineus sp. screened for this research was identified as Phellinus linteues through ITS rDNA sequencing method and blast search, demonstrating 99.7% similarity to other Phellinus linteus strains. Intensive strain improvement program was carried out by obtaining large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because large numbers of protoplasts ($1{\times}10^5{\sim}10^6\;protoplasts/ml$) formed using the banding filtration method with the cell wall-disrupting enzymes could be regenerated in relatively high regeneration frequency($10^{-2}{\sim}10^{-3}$) in the newly developed regeneration medium. It was demonstrated that the strains showing high performances in the protoplast regeneration and solid growth medium were able to produce 5.8~6.4%(w/w) of ${\beta}$-D-glucan and 13~15 g/L of biomass in stable manners in suspended shake-flask cultures of P. linteus mycelia. In addition, cell mass increase was observed to be the most important in order to enhance ${\beta}$-D-glucan productivity during the course of strain improvement program, since the amount of ${\beta}$-D-glucan extracted from the cell wall of P. linteus mycelia was almost constant on the unit biomass basis. Therefore we fully investigated the fungal cell morphology, generally known as one of the key factors affecting cell growth extent in the bioreactor cultures of mycelial fungal cells. It was found that, in order to obtain as high cell mass as possible in the final production bioreactor cultures, the producing cells should be proliferated in condensed filamentous forms in the growth cultures, and optimum amounts of these filamentous cells should be transferred as active inoculums to the production bioreactor. In this case, ideal morphologies consisting of compacted pellets less than 0.5mm in diameter were successfully induced in the production cultures, resulting in shorter period of lag phase, 1.5 fold higher specific cell growth rate and 3.3 fold increase in the final biomass production as compared to the parallel bioreactor cultures of different morphological forms. It was concluded that not only the high-yielding but also the good morphological characteristics led to the significantly higher biomass production and ${\beta}$-D-glucan productivity in the final production cultures.

• Journal of Aquaculture
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• v.9 no.2
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• pp.141-149
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• 1996

Effects of $17{\alpha}$-methyltestosterone ($17{\alpha}-MT$) in rearing water on sex reversal of Nile tilapia (Oreochromis niloticus) were investigated and optimum conditions as initial treatment time, concentrations and treatment durations of hormone were evaluated in this study. For the study of the optimum initial treatment time, 0 to 20-day-old fry were treated by immersion in a 500 ppb solution of $17{\alpha}-MT$. Desirable results were obtained at 12-day-old fish as $86.4\%$ of male induction rates and this frequency was obviously higher than the other age groups. Twelve-day-old fry were immersed in $17{\alpha}-MT$ solutions at concentrations of $0\~2,000$ ppb for 24 hours for the study of dose dependent relationship between sex ratios and concentrations of $17{\alpha}-MT$, Male induction rates of all treated groups were higher than $80\%$, $X^2$ values against the sex ratio of control group indicate that sex reversal has taken place effectively in all experimental groups (P<0.001). Futhermore, 500 ppb treated groups showed highest male incidence of $86.4\%$. Effects of 5 different durations (0, 12, 18, 24 and 30 hours) treated with 1,000 ppb of $17{\alpha}-MT$ were also evaluated. Male induction rate from 0 to 24 hours treated group was increased with treatment durations. However, male incidence of 30-hour treated group ($84.0\%$) was sligthly decreased compare to the 24-hour treated group ($85.2\%$). It is concluded that immersion treatment using $17{\alpha}-MT$ on O. niloticus is possible on sex reversal at low concentration of 500 ppb and short treatment durations within 24 hours with 12-old-day fry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1592-1599
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• 2013

Despite numerous studies regarding overweight or obese children, only a limited number of studies have investigated the effect of underweight. The purpose of this study is to investigate the determinants of underweight among school-aged children. A total of 493 students (86 underweight and 407 normal weight students) aged 11 to 13 years were included in our study. Socio-demographic characteristics, eating habits, health information, self-perception of weight, weight-control efforts and birth-related information were collected by using survey questionnaires for children and parents. Dietary information was obtained by two 24-hour food records, which were completed by both children and their parents. The prevalence of underweight was significantly higher in girls than boys, and the frequency of medical treatment and flu symptoms were higher in underweight children than normal ones. Overall, girls tended to overestimate their own weight; this misclassification was greater among underweight girls. Birthweight was positively correlated with current weight (P<0.05) and height (P<0.01) in girls, but these correlations were not seen in boys. In conclusion, underweight girls had inappropriate self-perception of weight, and underweight in girls may be related with birthweight and inadequate dietary intakes. Therefore, it is important to build a well-designed framework that integrates efforts of home, school, and community to maintain a healthy weight with balanced diet and exercise throughout the lifetime.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.95-101
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• 1998

The changes of electroencephalogram(EEG) in patients with dementia of Alzheimer's type are most commonly studied by analyzing power or magnitude in traditionally defined frequency bands. However because of the absence of an identified metric which quantifies the complex amount of information, there are many limitations in using such a linear method. According to the chaos theory, irregular signals of EEG can be also resulted from low dimensional deterministic chaos. Chaotic nonlinear dynamics in the EEG can be studied by calculating the largest Lyapunov exponent($L_1$). The authors have analyzed EEG epochs from three patients with dementia of Alzheimer's type and three matched control subjects. The largest $L_1$ is calculated from EEG epochs consisting of 16,384 data points per channel in 15 channels. The results showed that patients with dementia of Alzheimer's type had significantly lower $L_1$ than non-demented controls on 8 channels. Topographic analysis showed that the $L_1$ were significantly lower in patients with Alzheimer's disease on all the frontal, temporal, central, and occipital head regions. These results show that brains of patients with dementia of Alzheimer's type have a decreased chaotic quality of electrophysiological behavior. We conclude that the nonlinear analysis such as calculating the $L_1$ can be a promising tool for detecting relative changes in the complexity of brain dynamics.

• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.421-426
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• 2012

The purpose of this study was to investigate the knowledge of dental hygiene students of the quality assurance of dental radiation such quality assurance and related educational experiences in an effort to accelerate the preparation of a curriculum for systematic quality-assurance. The subjects in this study were 453 dental hygiene students who participated in dental radiography courses. Varied statistical analyses such as frequency analyses, reliability, chi-square, and independent samples t-tests were conducted on the data collected, using SPSS 12.0. Scheffe test was also used after one-way ANOVA as post-hoc tests. Results showed that (a) the students' acknowledge level of Radiographic Quality Assurance was $7.71{\pm}1.7$ out of 12 on average. The more theory and practical classes students took, the higher points they got (p<0.001); (b) Most of the students experienced 1-3 lessons out of 13 in practical training and 26.3% of students did not take any practical lesson. ;(c)Students who did not take any practical training got 7.20 points out of 13, students who took 1-3 lessons got 7.84 points out of 13, students who took 4-5 lessons got 7.87 points out of 13, and students who took more than 6 lessons got 8.14 points out of 13 on average. The more practical classes they took the higher acknowledge level they were. Therefore it needs to provide adequate practical lessons to them.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.129-137
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• 2008

Purpose : Human metapneumovirus (hMPV) was recently discovered in children with respiratory tract infection. The aim of this study was to determine the frequency and the clinical manifestation of hMPV infection in Korean children. Methods : From January to December, 2005, we collected throat swabs from 1,098 children who were hospitalized for acute respiratory illness at the Department of Pediatrics, Kwang-Ju Christian Hospital. hMPV was detected by performing reverse transcriptase-polymerase chain reaction (RT-PCR). The medical records of the patients with positive results were retrospectively reviewed. Results : We detected hMPV in 25 (2.2%) of the 1,098 hospitalized children. The mean age of the hMPV infected children was 2.3 years, and 84% of the illnesses occurred between April and June. The most common diagnoses were pneumonia (60%) and bronchiolitis (20 %). The clinical manifestations included cough, fever, coryza, rale, wheezing and injected throats. Peribronchial infiltration and consolidation were the common chest X-ray findings. Four (16%) of 25 patients with hMPV infection had exacerbation of asthma. Coinfection with other respiratory viruses was found in six children (24%). Conclusion : hMPV is the cause of an important proportion of acute respiratory tract infection in Korean children. Additional studies are required to define the epidemiology and the extent of disease caused by hMPV and to determine future development of this illness in Korean children.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.51-64
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• 2002

This study was aimed to provide the basic data for the development of effective educational program by reflecting the opinions of the visiting health service workers. The subjects were 144 visiting health service workers in Gwangju and Jeollanam-do area who responded the mail questionnaire. The data were collected from June to July, 2001 using questionnaire composed of the education need, knowledge by subjective appraisal, and experience of education. The major findings of this study were as follows: 1. The number of respondents who received at least one education within recent three years were 43(29.9%) at the central level, 57(39.6%) at the provincial level and 53(36.8%) at the district level. The satisfaction with education was higher at the central level than at the provincial and district level. 2. Knowledges by subjective appraisal on the 'chronic degenerative diseases management' and 'health promotion' was relatively high. while that of 'rehabilitation' was low. 3. The knowledge by subjective appraisal of visiting health service was related with experience of education and license status. The knowledge was higher in registered nurses than in nurse aids. The curricula related to increased level of knowledge of visting health service workers were 'elderly health care', 'rehabilitation' and 'psychiatric-mental health nursing' educations at the central level 'continuing education for the community health practioners' and 'psychiatric-mental health education' at the provincial level and 'elderly health care', 'rehabilitation' 'psychiatric-mental health' and 'acute diseases control' educations at the district level. 4. The respondents preferred elderly health management as the contents of education, officer group education as the method of education, province(30.4%) as the main body of education, exercise and practice as the form of education, 2-3 times per year as the frequency of education, and 3-5days as the period of education. The findings of this study could suggest that future education program should be planned to increae the knowledge level of visiting health service workers by reflecting their educational need.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.13-19
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• 2013

This study evaluated the change of color and the microhardness according to time-out using the office bleaching with in vitro test after bleaching one time 1 day per week, total three times, for the control group and three times per 1day for the experimental group. $L^*$ was increased in both groups. Group 1 showed a significant increase statistically between before and after tooth whitening (p<0.05). Group 2 showed a significant increase statistically between before and after tooth whitening (p<0.05). ${\Delta}E^*$ was huge in both groups. In group 1, it was great in terms of statistical significance between 1 day and 7 days after tooth whitening (p<0.05). In group 2, it was the greatest between before and 1 day after tooth whitening and was significant statistically as well (p<0.05). Vickers hardness number (VHN) decreased in both groups. In group 1, VHN decreased over time and the difference was significant statistically (p<0.05). In group 2, VHN decreased over time and the difference was significant statistically (p<0.05). Percentage microhardness loss was great in both groups. In group 1, it was the greatest between 1 day and 7 days after the treatment, and it was significant statistically (p<0.05). In group 2, it was the greatest between before and 1 day after the treatment, and it was significant statistically (p<0.05). Put together, the more frequent tooth whitening a day is, the longer the period of tooth whitening when applying the same frequency, the greater color change was, however the microhardness decreased, in regard to the results over time using 15% hydrogen peroxide tooth whitening product for professionals.