• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.2
• /
• pp.427-436
• /
• 1999

Preservation of the remaining periodontal ligament cells on an avulsed tooth is very important to the successful outcome of replantation. HBSS is recommended as the most suitable storage medium for the avulsed tooth that cannot be replanted immediately. But their availability near the site of an accident is doubtful. The purpose of this in vitro study was to compare periodontal ligament cells stored in different storage media obtained easily on the spot. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. Cells were cultured in ${\alpha}-MEM$ culture medium containing 20% FBS, at $37^{\circ}C$ 100% humidity, in a 5% $CO_2$ incubator. Cells were cultured in 96 well culture plate, $5{\times}10^4$ cells per well with ${\alpha}-MEM$ and incubated for 24 hours. After discarding the medium, those cells were cultured in ${\alpha}-MEM$ contained with 10% FBS, pasteurized milk, sterilized saline, unstimulated saliva and bench-dried state at $25^{\circ}C$ room temperature for 30, 60, 90, 120, 180 minutes respectively. And then each group was measured using MTT assay. The results were as follows. 1. Between the group of each time, there was statistically significant difference. Periodontal ligament cells viability was highest in pasteurized milk and was reduced stepwisely in sterilized saline, unstimulated saliva and bench-dried state(p<0.05). 2. between the time of each group, there was statistically significant difference(p<0.05) but was no statistically significant difference at 90-120 minutes in pasteurized milk and at 60-90 minutes and 120-180 minutes in sterilized saline(p>0.05). In conclusion, HBSS as storage medium of an avulsed tooth is not practical on the spot. Insteadily pasteurized milk can be recommended to maintain the periodontal ligament cells viability.

• The Korean Journal of Nuclear Medicine
• /
• v.35 no.1
• /
• pp.23-32
• /
• 2001

Purpose: Cortical dysplasia (CD) designates a diverse group of malformations resulting from one or more abnormalities in the development of the cerebral cortex. We investigated the findings of interictal SPECT and the diagnostic usefulness of interical and ictal SFECT according to pathological grading (PG) in comparison with MRI. Materials and Methods: This study included 16 patients (M:F=9:7, age: $19.9{\pm}11.8$ yrs) with pathologically proven CD. Tc-99m ECD SPECT was performed in all patients: interictal 11, interictal and ictal 3, ictal 2. MRI were obtained in all patients and image analysis was done blindly as to the result of SPECT. Pathologic findings of CD were classified into grade 1 G1, dyslamination), grade 2 (G2, dysplastic neurons) and grade 3 (G3, balloon cells). We compared SFECT with MRI in lesions-to-lesions and analyzed the result according to PG. Results: In SFECT and MRI. 38 and 27 lesions were visually recognized. In 14 interictal SPECT, variable findings in 35 lesions were demonstrated: 25 were hypoperfusion, 7 hyperperfusion, 2 heterotopic perfusion in the white matter. By comparison between two studios, missed lesions were founded: SPECT were 1 lesion, MRI 12. Review of missed 12 lesions of MRI were followed according to PG: G1 patients were 16.7% (4/19), G2 40.0% (6/15), and G3 50% (2/4). Conclusion: Interictal SFECT in CD showed variable findings such as hypoperfusion, hyperperfusion or heterotopic perfusion. However, for detection of missed CD on MRI, SFECT may help to detect a functional abnormality of the lesion with high PG.

• Korean Journal of Digital Imaging in Medicine
• /
• v.9 no.1
• /
• pp.37-43
• /
• 2007

1. Purpose : This study is to present effective exposure conditions to acquire the best image of simple abdomen in Film Screen (F.S) system and Computed Radiography (C.R) system. 2. Method : In the F.S system, while an exposure condition was fixed as 70kVp, images of a patients simple abdomen were taken under the different mAs exposure conditions. Among these images, the best one was chosen by radiologists and radiological technologists. In the C.R system, the best image of the same patient was acquired with the same method from the F.S system. Both characteristic curves from F.S system and C.R system were analyzed. 3. Results : In the F.S system, the best exposure condition of simple abdomen was 70kVp and 20mAs. In the CR system, with the fixed condition at 70kVp, the image densities of human organs, such as liver, kidney, spleen, psoas muscle, lumbar spine body and iliac crest, were almost same despite different environments (3.2mAs, 8mAs, 12mAs, 16mAs and 20mAs). However, when the exposure conditions were over or under (below) 12mAs, the images between the abdominal wall and the directly exposed part became blurred because the gap of density was decreased. In the C.R system, while the volume of mAs was decreased, an artifact of quantum mottle was increased. 4. Conclusion : This study shows that the exposure condition in the C.R system can be reduced 40% than in the F.S system. This paper concluded that when the exposure conditions are set in CR environment, after the analysis of equipment character, such as image processing system(EDR : Exposure Data Recognition processing), PACS and so on, the high quality of image with maximum information can be acquired with a minimum exposure dose.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.6
• /
• pp.493-501
• /
• 1999

Purpose: We conducted a comparative study to evaluate the diagnostic values of T1-201, Tc-99m MIBI and I-131 scans in the follow-up assessment after ablative I-131 therapy in differentiated thyroid cancer. Materials and Methods: The study population consisted of 20 patients who underwent surgical removal of thyroid cancer and ablative radioactive iodine therapy, and followed by one or mote times of I-131 retreatments (33 cases). In all patients, T1-201, Tc-99m MIBI, diagnostic and therapeutic I-131 scans were performed and the results were analyzed retrospectively. Also serum thyroglobulin levels were measured in all patients. The final diagnosis of recurrent or metastatic thyroid cancer was determined by clinical, biochemical, radiologic and/or biopsy findings. Results: Positive rates (PR) of Tc-99m MIBI, T1-201, diagnostic and therapeutic I-131 scans in detecting malignant thyroid tissue lesions were 70% (19/27), 54% (15/28), 35% (17/48) and 63% (30/48), respectively. The PR in the group of 20 cases (28 lesions) who underwent concomitant T1-201 and I-131 scans were in the order of therapeutic 131 scan 71%, T1-201 scan 54% and diagnostic I-131 scan 36%. There was no statistically significant difference between T1-201 and diagnostic I-131 scans (p>0.05). In the group of 20 cases (27 lesions) who underwent concomitant Tc-99m MIBI and I-131 scans, the PR were in the order of Tc-99m MIBI scan 70%, I-131 therapeutic scan 52% and I-131 diagnostic scan 33%. The PR of Tc-99m MIBI was significantly higher than that of diagnostic I-131 scan (p<0.05). Conclusion: Tc-99m MIBI scan is superior to diagnostic I-131 scan in detecting recurrent or metastatic thyroid cancer following ablation therapy in patients with differentiated thyroid cancer. T1-201 scan did not showed significantly higher positive rate than diagnostic I-131 scan. Instead of diagnostic I-131 scan before the I-131 retreatment, Tc-99m MIBI scan without discontinuing thyroid hormone replacement would be a prudent and effective approach in the management of these patients.

• Clinical and Experimental Pediatrics
• /
• v.49 no.12
• /
• pp.1315-1323
• /
• 2006

Purpose : This study was conducted to compare the efficacy and safety of ibuprofen and indomethacin in the treatment of patent ductus arteriosus (PDA) in preterm infants and to determine whether ibuprofen can be an alternative drug. Methods : A total of 32 preterm infants with symptomatic PDA were enrolled in the study. Twelve infants received intravenous ibuprofen 10 mg/kg, followed by 5 mg/kg after 24 and 48 hours. As a comparative group, twenty premature infants received three doses of indomethacin 0.1-0.2 mg/kg every 12 hours. Results : PDA was closed in 11 of 12 infants of the ibuprofen group (92 percent) and in 18 of 20 infants of the indomethacin group (90 percent). Serum sodium concentration decreased along with time significantly (P<0.0001) and to its lowest level at 48 hours after administration of the third dose (P=0.0011) in both groups, but showed no significant difference between two groups. Serum BUN and creatinine concentrations were not changed significantly before or after treatment in each group and showed no difference between thetwo groups. The amount of urine output did not change along with time significantly in both groups (P=0.0725), and showed no significant difference between two groups. Conclusion : Ibuprofen has similar effects to indomethacin in the rate of PDA closure and complication when compared. It has similar changes in serum sodium level and complications when compared to indomethacin for the treatment of PDA in preterm infants. Therefore, intravenous ibuprofen may be used as an alternative agent in the treatment of symptomatic PDA in preterm infants.

• Journal of Conservation Science
• /
• v.30 no.2
• /
• pp.181-187
• /
• 2014

AThe studies on ceramic preservation have been conducted widely in various institutions such as national/ public museums and research labs as well as the excavation institutions and university museums. Although there are some differences in preservation methodologies and materials used across the institutions, the variation is minimal. Specifically, epoxy resin is mostly used for ceramic restoration for its high cohesiveness, low contraction and high strength although there are some variations in for Ceramic Preservation. The synthetic resin type used according to the type of damage in the ceramic. However, the yellowing or the change of color across the time after the restoration is the weakness of epoxy resin. In this study, we aim to develop a material which minimizes this yellowing of epoxy resin while enhancing its cohesiveness and strength as well as other physical properties. We made the new material to have similar properties with those used widely for the ceramic restoration, such as EPO-TEK301$^{(R)}$, L30$^{(R)}$, XTR-311$^{(R)}$ through comparative experiments. The cohesiveness of the newly developed resin was improved to 2.51(MPa), which is similar level of XTR-311$^{(R)}$ of the 2.30(MPa) but about 2x higher than the other resins EPO-TEK301$^{(R)}$, L30$^{(R)}$ (1.21 and 1.81 (MPa), respectively). Especially, the experiment on yellowing shows that the existing resins show the range of color change at 10~25(${\Delta}E^*ab$), but the new low yellowing epoxy resin has the color change value at 8.3 (${\Delta}E^*ab$), the value lowering the yellowing effect to 1 to 3 times of the existing epoxy resin, thereby solving the issue of generating sense of differences due to change of color or yellowing.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.11 no.1
• /
• pp.30-36
• /
• 2012

Purpose: We compared the clinical and radiological results of meniscectomy with HTO or without HTO for degenerative medial meniscus posterior horn with varus deformity. Materials and Methods: Forty-two patients who had medial meniscus degenerative root tear with varus deformity more than 3 degrees were included for this study. Among them, 30 patients were performed meniscectomy combined with open wedge HTO and 12 patients were performed only meniscectomy without HTO. The mean follow-up period was 52.5 months. The clinical results were evaluated based on symptom improvement, patients' subjective satisfaction for surgery and HSS score. We also compared the osteoarthritic progression between the group on preoperative and at the final follow up radiographs. Results: Symptom improvement was achieved in 83.3% (25 cases) with HTO group and 66.7% (8 cases) without HTO group at final follow up with a significant difference. Patients' satisfaction was achieved in 83.3% (25 cases) with HTO group and 58.3% (7 cases) without HTO group which has a significant difference. The HSS score was improved in both group (90.8: with HTO group, 89.0: without HTO group) at the final follow up without significant difference. WOMAC score was improved in both groups at the final follow up without significant difference. There were no significant differences in the osteoarthritic progression between two groups. Conclusion: The good clinical result for treatment of patient who have medial meniscus degenerative root tear with varus deformity, proximal high tibial osteotomy is considered absolutely necessary. However, the progression of degenerative arthritis, its effect on long term follow up will be needed.

• Journal of the Economic Geographical Society of Korea
• /
• v.18 no.1
• /
• pp.87-102
• /
• 2015

This study attempts to introduce the methodology for accounting real-time population distribution in the urban areas. For the purpose, we utilize the media user's time-space information from the media users' media diaries in the media panel survey databases. We analyze the space-time population rate for each activity space related with everyday urban lifes. Seoul has been selected as a case study area, since space-time information are relatively rich there, and thus the comparisons are available. The space-time population rates have been verified by the comparative analysis with the T-card results. We propose a real time population measurement method by combination of the space-time population rate with geographical data. The real time population of each activity space at each dong in Seoul has been calculated by multiplying the space-time population rates to the numbers of employer of three categories of activity spaces(residential, working, and commercial). By utilizing GIS, we visualize the results of two time points (3AM and 3PM) and then analyze the spacio-temporal characteristics of real time population distribution in Seoul. The Day time population distribution pattern shows strong relationships with the distribution of business and commercial activities, while the night time population distribution pattern can be explained by resident population distribution almost perfectly.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.39 no.6
• /
• pp.57-66
• /
• 2011

This study researched those universities for which fence opening and greening projects are being conducted by Seoul city. The forms of opened fences at 24 universities which have accomplished this project were classified into several types for each type of university, representative cases with many diverse facilities and active users were selected and investigated. The study was carried out using methods of field observations, literature review, and surveys. To maintain the confidentiality of the collected questionnaire analysis, the analysis of each type's usage frequency, overall satisfaction and a regression analysis with space environment and facilities, a one-way ANOVA for was used to validate the difference between types regarding satisfaction with the project. The results of usage type analysis were found to agree with the 3 analysis criteria-- installation location, user characteristics, and usage purpose--which were the legislative concepts. In overall satisfaction with facilities, it appeared that except for Seoul Women's College of Nursing with its rural district neighborhood type park, users were satisfied: with the small urban neighborhood park of Methodist Theological College, Konkuk University's small urban square park, and Sejong University's green space small city park. In general, users appeared to not have satisfaction with such features as fountains / hydroponic facilities, fitness facilities, and square facilities, which should be taken into consideration when pursuing further opening and greening projects. Regarding full satisfaction with the space environment, it was found that users were not satisfied with Seoul Women's College of Nursing's rural district neighborhood-style park, whereas they were satisfied with Methodist Theological College's small urban neighborhood park, Konkuk University's small urban square-style park, and Sejong University's green space small city park. In addition, it was shown that facilities use, convenience and privacy of the four parks were largely unsatisfactory for users, and that the small city parks located at roadsides were unsatisfactory regarding noise level, both of which should be most highly considered when conducting similar projects in the future.

• The Journal of Korean Academy of Prosthodontics
• /
• v.51 no.3
• /
• pp.160-166
• /
• 2013

Purpose: The purpose of this study was to compare the fracture strength of traditional metal-ceramic crowns and full zirconia crowns according to the occlusal thickness. Materials and methods: A mandibular first molar resin tooth was prepared with 1.5 mm occlusal reduction, 1.0 mm rounded shoulder margin and $6^{\circ}$ taperness in the axial wall. Duplicating the resin tooth, 64 metal dies were fabricated. 48 full zirconia crowns were fabricated using Prettau zirconia blanks by ZIRKONZAHN CAD/CAM and classified into six groups according to the occlusal thickness (0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm). 16 metal-ceramic crowns were fabricated and classified into two groups according to the occlusal porcelain thickness (1.0 mm, 1.5 mm). All crowns were cemented on each metal die and mounted in a universal testing machine. The load was directed at the functional cusp of each specimen until catastrophic failure occurred. One-way ANOVA, Tukey multiple comparison test (${\alpha}=.05$) and t-test (${\alpha}=.05$) were used. Results: The results were as follows. 1. The test 1 group (646.48 N) showed the lowest fracture strength (P<.05), and the value of the test 2.3.4.5 groups (866.40 N, 978.82 N, 1196.82 N, 1222.41 N) increased as thickness increased, but no significant difference were found with the groups (P>.05). The value of test 6 group (1781.24 N) was significantly higher than those of the other groups (P<.05). 2. There were no significant differences of the fracture strength of metal ceramic crowns according to occlusal porcelain thickness 1.0 mm (2515.71 N) and 1.5 mm (3473.31 N) (P<.05). Conclusion: Full zirconia crown needs to be 1.0 mm or over in occlusal thickness for the posterior area to have higher fracture strength than maximum bite force.