• Restorative Dentistry and Endodontics
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• v.31 no.5
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• pp.398-408
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• 2006

The purpose of this study was to verify the usefulness of MTT analysis as a tool of measurement of the periodontal ligament cell viability from the extracted rat molar. A total of 80 Sprague-Dawley white female rat of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted under Ketamine anesthesia. Twenty-four teeth of each group (divided as five groups depending upon the time-lapse after extraction such as Immediate, 10, 20, 40 and 60 minutes) were immersed in $200{\mu}l$ of MTT solution (0.5 mg/ml) and processed for optical density measurements. Another 10 teeth of each group were treated as same as above and sectioned at $10{\mu}m$ for microscopic examination. All measurements values were divided by the value of hematoxylin-eosin staining which represented the volume of each corresponding samples. Immediate and 10 minute groups showed highest MTT values followed by 20, 40, and 60 minutes consecutively. Statistical significance (p<0.05) existed between all groups except in immediate versus 10 minute groups and 40 versus 60 minutes. Histological findings also showed similar findings with MTT results in crystal shape and crystal numbers between the experimental groups. These data indicate that in vivo MTT analysis nay be of value for evaluation of the periodontal ligament cell viability without time- consuming cell culturing processes.

• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.522-529
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• 2007

The purpose of this study was to compare the apical leakage of the root canal filled with the System B and the EndoTwinn(the combined application of heat and ultrasonic vibration). Sixty extracted premolars with straight root were cleaned and shaped to size 35. Group SB was obturated using System B and Group ET was filled with EndoTwinn. A size 35 of 0.06 tapered gutta-percha and Adseal were used and the plugger which could be introduced to 4 mm short of working length was selected in the obturation procedure. As the positive control, Group PC was not filled. In Group SB, ET and PC, all external surfaces of each tooth were coated with nail varnish leaving only 1 mm area around the apical foramen. In the negative control of Group NSB and Group NET, all of external tooth surface including apical foramen was coated with the nail varnish. The specimens were immersed in methylene blue dye solution for 2 days. Then the specimens were sectioned at each 1 mm from apex to 5 mm level. The final score of one specimen was given by summing up of the points at all levels. The dye leakage of Group ET was significantly less than that observed in Group SB (p < 0.05). And the frequency of gutta-percha pulling out from root canal when the plugger was removed was more often with the System B than with EndoTwinn but there was no significant difference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.729-733
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• 2005

This study was conducted to sanitize fried-frozen cheese ball by gamma irradiation. Total aerobic bacteria and yeasts and molds counts were 4.4 and 2.8 log CFU/g in non-irradiated sample, respectively. Microorganisms were decreased with increase of irradiation dose $(D_{10}=1.25\;kGy)$, and were not detected in samples irradiated at 3 kGy or more $(<10^2\;CFU/g)$. $D_{10}$ value for Escherichia coli (KCTC 1682) was 0.25 kGy. TBA (2-thiobarbituric acid) values were increased as irradiation dose was increased, but there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less (p<0.05). The results of sensory evaluation showed that there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less, the sensory scores were decreased with irradiation at 5 kGy or more (p<0.05). These results indicated that gamma irradiation at 3 kGy was considered to be an effective treatment to ensure the microbiological safety of fried-frozen cheese balls without any sensorial change, even though further studies should be investigated to reduce detrimental effects induced by irradiation.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1417-1423
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• 2011

For evaluating the effect of various organic fertilizer ratios on the Spiraea${\times}$bumalda 'Gold Mound' growth, a container green wall system experiment was conducted in a greenhouse at Konkuk university. The experimental planting grounds were prepared with different organic fertilizer ratios ($A_1L_0$, $A_8L_1$, $A_4L_1$ $A_2L_1$ and $A_1L_1$) and with drought tolerance and an ornamental value Spiraea${\times}$bumalda 'Gold Mound' was planted. The change in soil moisture contents, plant height, number of branches, number of dead leafs, number of leaf, number of shoots, length of node, length of leaf, width of leaf, root-collar caliper, chlorophyll contents and survival rate were investigated from April to Jun 2010. 1. The result of soil moisture contents was analyzed with weight unit in the container green wall system during the dry summer season. The soil moisture contents were significantly enhanced in the container green wall system in increasing order as the amount of fertilizer level increased $A_1L_1$ > $A_2L_1$ > $A_4L_1$ > $A_8L_1$ > $A_1L_0$. 2. Compared to the control treatment (amended soil with 100% + organic fertilizer 0%) application, the highest plant growth was observed in the treatment of $A_2L_1$(amended soil with 67% + organic fertilizer 13%) application. However, the differences between the organic fertilizer ratio treatments of $A_1L_1$, $A_4L_1$, $A_8L_1$, and the $A_1L_0$ organic fertilizer application were mostly not significant. 3. The survival rate increased with the increasing application of organic fertilizer, but in the control treatment (amended soil with 100% + organic fertilizer 0%) application all the plants died. Experimental results from the presented study clearly demonstrated that the organic fertilizer improved the survival rate more than the Spiraea${\times}$bumalda 'Gold Mound' growth at different levels of organic fertilizers. This strain can be utilized as a plant growth application in living wall systems during the dry summer season. Therefore, Spiraea${\times}$bumalda 'Gold Mound' is expected to be a highly valuable shrub for the green wall system if it should be considered in integration with stormwater retention or as a soil conditioner for increasing soil water contents in planting ground.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.51-61
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• 2001

Cleft lip and/or palate (CLP) is one of the most common congenital craniofacial anomalies and occurs more frequently in Asian people. Dental abnormalities in number, size, shape, and eruption of teeth are frequently associated with CLP. The purposes of this study were to investigate the effects of CLP on number, size, shape and eruption of teeth and to provide basic clinical data for diagnosis and treatment of the CLP patients. With the orthodontic and cleft charts, diagnostic models, orthopantomograms and intraoral x-ray films from 241 CLP patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital, we evaluated the frequency of congenital missing teeth, supernumerary teeth, Impacted teeth, and microdontia. The results were as fellows ; 1. Frequency of congenital missing was relatively high up to $56.8\%$. Congenital missing occurred frequently in the maxillary lateral incisor and the maxillary second premolar. Among the CLP types, frequencies of congenital missing in cleft lip and Palate group and cleft lip and alveolus group were higher than those of cleft lip group and cleft palate group. And bilateral cleft showed higher frequencies than unilateral ones. 2. Supernumerary tooth was shown in $11.2\%$ of CLP patients. It occurred frequently in the area between the maxillary lateral Incisors and the maxillary canine. Among the CLP types, cleft lip group showed relatively most highest frequency. 3. Impaction was shown in $18.3\%$ of CLP patients. It occurred most frequently In the maxillary lateral incisor and the maxillary canine than other teeth. Among the CLP types, cleft lip group and cleft lip and palate group showed most highest frequencies. 4. Microdontia was shown in $15.8\%$ of CLP patients. It occurred the most frequently In the maxillary lateral incisors and maxillary canines. Among the CLP types, cleft lip and alveolus group and cleft lip and palate group showed relatively higher frequencies. There was no microdontia in cleft palate group.

• The korean journal of orthodontics
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• v.34 no.2 s.103
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• pp.165-175
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• 2004

Information on the limits of treatment could allow for more rational treatment Planning and better results after treatment. From this point of view, this article has attempted to discuss the limits of orthodontic tooth movement. A relatively wider range of tooth movement is expected after Class III surgical-orthodontics than after conventional orthodontic treatment in general. The purposes of this Paper were: first, to evaluate the reliability of teeth position measuring gauge; and second, to elucidate the limits of orthodontic tooth movement. Dental casts of fifty-fine subjects were analyzed by using Set-up model checker (InVisitec Co., Korea) before and aster the Class III surgical-orthodontic treatment. The changes of maxillary and mandibular dental arch widths were also measured from the canines to the second molars. To test the inter-examiner reliability, randomly selected casts were measured by another examiner. Descriptive statistics and paired t tests were used to explain the tooth movement during treatment. The results showed a relatively good reliability of measuring instruments and a very diverse range of tooth movement. Collective changes by the orthodontic tooth movement evaluated in Class III surgical-orthodontics allowed for a suggestive interpretation of specific treatment patterns. Arch width changes during the inter-arch coordination were mainly the result of tipping in both buccal segments. Based on the results of this study, the possibility of a change in dentition as a result of orthodontic treatment should be understood in order to launch a well-organized plan of treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.43-52
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• 2006

Topical fluoride application for children is a widely peformed procedure in the field of pediatric dentistry to prevent dental caries. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials as it roughens the surface of the restorative materials. The aim of this study was to evaluate the surface changes in composite resins to topical fluoride. Composite resins(Z $250^{(R)}$, Ultraseal $XT^{(R)}$ Filtek $flow^{(R)}$ $Revolution^{(R)}$, $Denfil^{(R)}$) in topical fluoride agents were immersed and their surface roughness, weight loss and SEM were evaluated. The results were as follows : 1. The 4 minutes-immersion groups showed more roughened surface than 1 minute-immersion groups and the control groups showed the smoothest surface among all the materials, and there was statistically significant difference except the revolution between the groups. 2. There was no significant difference between the 1 minute-immersion groups and 4 minutes-immersion groups in weight loss. 3. The experimental group treated with topical fluoride gel showed the generally mere roughened surface than control group in the SEM findings.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.517-524
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• 1999

Background : Airway inflammation and hyperresponsiveness are recognized as major characteristics of bronchial asthma. Airway inflammation has usually been assessed by invasive methods, e.g. BAL or bronchial biopsy, but recent studies proposed induced sputum as another reliable and non-invasive tool to investigate airway inflammation in asthmatic patients. Thus, the relationship between airway inflammation assessed by induced sputum and airway hyperresponsiveness was investigated in asthmatic patient. Method : Airway responsiveness was determined by the concentration that caused a 20% decrease in $FEV_1$($PC_{20}$) after inhaling incremental concentrations of methacholine. The numbers of inflammatory cells and the concentration of eosinophilic cationic protein(ECP) were assessed in induced sputum obtained by inhalation of hypertonic saline(3%). Result: We analyzed sputum induced in 15 stable asthmatic patients. The differential cell count(%) of macrophages, neutrophils, eosinophils and lymphocytes in induced sputum were $39.1{\pm}27.0%$, $29.6{\pm}21.0%$, $28.8{\pm}18.8%$, $1.3{\pm}3.1%$ respectively. The mean value of baseline FEV1(predicted) and ECP were $76.3{\pm}30.3%$ and $1,101{\pm}833{\mu}g/L$ respectively. The geometric mean value of $PC_{20}$ was 0.56 mg/mL. The relationships between the sputum eosinophil and ECP in induced sputum, and between sputum eosinophil and degree of airway responsiveness($PC_{20}$) were found to be significantly correlated (r=0.81, p<0.05 and r=-0.78, p<0.05, respectively). Sputum neutrophils and $PC_{20}$ were not correlated to each other (r=0.11, p=0.69) and a significant negative correlation was found between ECP and baseline $FEV_1$(predicted)(r=-0.62, p<0.05). Conclusion : The results of this study suggest that an induced sputum via a inhalation of hypertonic saline is useful to determine a patient's status of airway inflammation, and airway inflammation is one of the major causal factors in the development of bronchial hyperresponsiveness in asthmatic patients.

• Journal of Korean Home Economics Education Association
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• v.18 no.3 s.41
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• pp.81-95
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• 2006

The purpose of this study was to evaluate appropriateness of clothing & textiles as educational contents in practical arts or technology home economics in the 7th curriculum. The factors of appropriateness were the amounts of learning, the degrees of understanding, interest and requirement on the educational content recognized by elementary, middle and high school students. The data collected from evaluation sheets were analyzed by frequency analysis, t-test, crossing analysis using SPSSWIN 12.0 program. Results were as follows; First. more than 50% of elementary, middle and high school students were recognized the amounts of tearing of clothing & textiles proper. But boy students of middle school recognized 'making clothes' in practice course too heavy. Second. It were from easy to difficult that the degrees of understanding on the educational contents of clothing & textiles recognized by elementary school students. Elementary school students understood both 'making cushion' and 'sewing machine theory and practice' difficult. Middle school students understood 'basic sewing for repairing clothes' and 'making clothes' difficult whereas high school students thought 'making pillow' and 'making bag' difficult. All students understood practice courses hard. Third, the degrees of interest showed from 'interest' level to 'not interest' level in case of elementary school students whereas 'interest' level in middle school students and 'common' in high school students. Fourth, the requirements of elementary, middle and high school students were in 'necessary' level to 'common' level. Editional contents such as 'learning sewing machine', 'making cushions'. 'making clothes', and 'making pillow-cover and bag' were low in the degrees of requirement. The correlationship between the amount of learning and the each level of understand, interest and requirement of students was indirect. On the other hand, Among the level of understand, interest and requirement were direct in case of high school students.

• Journal of Korean Home Economics Education Association
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• v.19 no.2
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• pp.1-12
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• 2007

This study analyzed the recognition and utilization regarding teacher's guidebook for middle school technology-home economics class in the 7th Educational Curriculum. The data were collected via e-mail to teachers teaching home economics in middle schools. These e-mail addresses were acquired from middle school web pages registered on the Educational Board. The 355 data were analyzed using the SPSS program. The results were as follows: First, teachers recognized highly the necessity of teacher's guidebook. However, as the actual guidebook was not adequately helpful, the overall degree of satisfaction was relatively low. Teachers utilizing guidebook had more positive recognition on teacher's guidebook than teachers who did not. And teachers majored in technology education thought teacher's guidebook more helpful compared with teachers majored in home economics education. Second, teachers referenced teacher's guidebook mostly for field practice guidance. Third, teachers who did not utilize teacher's guidebook used other reference materials such as Internet Web sites and audiovisual materials. They were most commonly used for the reason that the contents were ample and easy to access. Fourth, the followings were suggested to improve teacher's guidebook. The provision of learning contents that can be practically used in class, the various samples of teaching-learning method, the specified methods of planning and criteria for performance assessment, the adequate supplementations regarding textbook contents, and the improvement of the outward layout format of the guidebook.