• Radiation Oncology Journal
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• v.19 no.2
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• pp.95-99
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• 2001

Purpose : To evaluate the effectiveness and tolerance of postoperative external radiotherapy for patients with intracranial meningiomas. Materials and Methods : The records of thirty three patients with intracranial meningiomas who were treated with postoperative external irradiation at our institution between Feb, 1988 and Nov, 1999 were retrospectively analyzed. Median age of patients at diagnosis was 53 years with range of 17 to 68 years. Sites of involvement were parasagital, cerebral convexity, sphenoid ridge, parasellar and tentorium cerebelli. Of 33 evaluated patients, 15 transitional, 10 meningotheliomatous, 4 hemangiopericytic, 3 atypical and 1 malignant meningioma were identified. Four patients underwent biopsy alone and remaining 29 patients underwent total tumor resection. A dose of 50 to 60 Gy was delivered in 28-35 daily fractions over a period of 5 to 7 weeks. Follow-up period ranged from 12 months to 8 years. Results : The actuarial survival rates at 5 and 7 years for entire group of patients were 78% and 67%, respectively. The corresponding disease free survival rates were 73% and 61%, respectively. The overall local control rate at 5 years was 83%. One out of 25 patients in benign group developed local failure, while 4 out of 8 patients in malignant group did local failure (p<0.05). Of 4 patients who underwent biopsy alone, 2 developed local failure. There was no significant difference in 5 year actuarial survival between patients who underwent total tumor resection and those who did biopsy alone. Patients whose age is under 60 showed slightly better survival than those whose age is 60 or older, although this was not statistically significant. There was no documented late complications in any patients. Conclusion : Based on our study, we might conclude that postoperative external beam radiotherapy tends to improve survival of patients with intracranial meningiomas comparing with surgery alone.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.649-652
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• 2012

회전익항공기의 연료셀 내부는 연료보관 및 연료를 엔진으로 공급하기 위한 배관과 구성품들이 배치되어 있다. 특히, 기동헬기는 전장에서 사용되는 헬기로써, 수 km 고도에서 비행하는 고정익기보다 비행고도가 낮기 때문에 피탄될 가능성이 높다. 따라서, 항공기의 생존성을 극대화하기 위해서는 피탄시 유체내부 상승압력에 의한 내부 LRU 가 받는 영향성을 검토하여 설계되어야 함은 주지의 사실이다. 그러나, 내탄시험은 연료셀 자체의 제작비용 및 준비기간이 상당히 소요되고, 실탄사용에 따른 시험수행의 제약 때문에 수치모사를 통한 관련 데이터의 확보가 필요하다. 이를 위해 본 연구에서는 유체-구조 수치모사 프로그램인 Autodyn을 이용하여 회전익항공기 연료셀의 내탄 수치모사를 수행하여, 피탄 후 연료셀 내부에서의 탄 거동을 분석하고 유체내부의 압력과 연료 셀 자체의 등가응력을 평가하였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.12-20
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• 2021

The purpose of this retrospective study was to evaluate the survival rate by comparing Class II restoration using flowable resin composite with stainless steel crown in primary molars. Electronic medical records and radiographs of 1,504 primary molars with proximal caries of 590 patients from June 2015 to August 2019 were analyzed. With the collected data, survival analysis was performed using the Kaplan-Meier method. The 1-year survival rate of flowable resin composite in the primary molar was 98.5%, 3-year survival rate was 87.7%, and mean survival time was 39 months. There was no statistically significant difference between flowable resin composite and stainless steel crown (p = 0.896). Within the limits of this study, Class II restoration using flowable resin composite can be considered a promising option for the treatment of proximal caries in primary molars.

• International Journal of Highway Engineering
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• v.5 no.3 s.17
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• pp.31-42
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• 2003

The KHC Test Road project was initiated on 1991 to develop Korean Pavement Design Guide. It was constructed along the Joongbu Inland Expressway line between Yeoju and Gamgok. It is two-lane wide expressway containing fifteen asphalt and twenty-five Portland cement concrete test pavement sections. Various sensors were installed in the Test Road to evaluate the behavior of test pavement sections under the influence of traffic load and environmental change. The most important issues in the sensor installation are the accurate location and long-term survivability. They are directly influenced by the sensor installation methodology. The methodology for asphalt strain gages is mainly discussed in this paper because it is the second important sensors in the KHC Test Road project. In order to find the best methodology, we evaluated existing methodology from prior experience and several conducted test installations. We have tried mound, block out, and trench cuts since 2000. Among three methods, block out was the most effective one in terms of accurate location, long-term survivability, and material homogeneity. However, this method cannot be applied to the wearing coarse so that the mound method was used as an alternative. The block out method was applied to base and intermediate layers while the mound method was used to the wearing coarse. Three hundred seventy-four asphalt strain gauges were installed on asphalt pavement sections from September 3rd to November 18th in 2002. According to the sensor measurement evaluation, 6.3% of sensor demonstrated over ranged readings for mound method installation and 2.5% did for block out method installation. We lost only two sensors during the installation. It is 99.5% survival and it is excellent survival rate according to other experience.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.653-659
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• 2020

This study was focused on the synthesis of methoxy polyethylene glycol-oleanolic acid ester (mPEG-OA derivative) and investigation of its water solubility and anti-melanogenic effects. mPEG-OA derivative was identified by 1H and 13C NMR and FT-IR spectroscopic measurements. The water solubilities of mPEG-OA derivative and OA were found to be 13 and 0.013 mg/mL and that of mPEG-OA was found to be 1000-fold higher than that of OA. The effects of mPEG-OA derivative and OA on cell viability were measured using B16F10 melanoma cells. The viability of cells treated with mPEG-OA derivative (250 μM) increased 4-fold compared to that of cells treated with OA (62.5 μM). At mPEG-OA derivative and OA concentrations where the cell viability was unaffected, the inhibitory effect of mPEG-OA derivative and OA on the melanogenesis in B16F10 melanoma cells were 36 and 35% at 50 and 10 μM, respectively. The expression level of microphthalmia-associated transcription (MITF) was also reduced in B16F10 melanoma cells treated with mPEG-OA and OA. Overall, mPEG-OA derivative showed excellent water solubility and inhibitory effects of the melanogenesis, which could be used as a potential formulation for use in whitening functional cosmetic material.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.3
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• pp.307-317
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• 2023

Due to increasing demand for aesthetics, zirconia crowns have become a popular choice for treating primary molars. However, there is limited literature available comparing the survival rates of zirconia crowns with those of other restorative materials. The objective of this study was to compare the 36-month survival rates of zirconia crowns and stainless steel crowns for proximal caries, as well as to analyze failure types associated with each crown type. Electronic medical records and radiographs of 1,061 primary molars from 498 patients treated with 2 types of prefabricated crowns at Chosun University Dental Hospital and 2 private dental clinics between 2017 and 2019 were collected and analyzed. The survival rate of zirconia crowns was found to be lower compared to that of stainless steel crowns. Regarding the groups without pulp treatment, the survival rate of stainless steel crowns was significantly higher than that of zirconia crowns. However, in the groups that received pulp therapy, no significant difference in the survival rates was observed between the two preformed crowns. Notably, abnormal root resorption or periapical lesions were identified as the primary cause of restorative failure in stainless steel crowns, whereas loss of restoration was the predominant cause in zirconia crowns. This study holds valuable implications for clinicians when selecting preformed crowns for primary molars.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.325-331
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• 1998

Purpose: We evaluated the importance of redistribution and 24 hour reinjection images in T1-201 SPECT assessment of myocardial viability after acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress-4 hour redistribution-24 hour reinjection T1-201 SPECT in 43 patients with recent AMI (4-16 days). The myocardium was divided into 16 segments and perfusion grade was measured visually with 4 point score from 0 to 3 (absent uptake to normal uptake). A perfusion defect with stress score 2 was considered moderate. A defect was considered severe if the stress score was 0 or 1 (absent uptake or severe perfusion decrease). Moderate defect on stress image were considered viable and segments with severe defect were considered viable if they showed improvement of 1 score or more on redistribution or reinjection images. We compared the results of viability assessment in stress-redistribution and stress-reinjection images. Results: On visual analysis, 344 of 688 segments (50%) had abnormal perfusion. Fifty two (15%) had moderate perfusion defects and 292 (85%) had severe perfusion defects on stress image. Of 292 severe stress defects, 53 were irreversible on redistribution and reversible on reinjection images, and 15 were reversible on redistribution and irreversible on reinjection images. Two hundred twenty four of 292 segments (76.7%) showed concordant results on stress-redistribution and stress-reinjection images. Therefore 24 hour reinjection image changed viability status from necrotic to viable in 53 segments of 292 severe stress defect (18%). However, myocardial viability was underestimated in only 5% (15/292) of severe defects by 24 hour reinjection. Conclusion: The 24 hour reinjection imaging is useful in the assessment of myocardial viability. It is more sensitive than 4 hour redistribution imaging. However, both redistribution and reinjection images are needed since they complement each other.

• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.56-62
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• 2005

Chemical analyses are generally used to assess contaminated soils and to monitor the efficiency of soil remediation. In this study, the ecotoxicological methods was suggested to evaluate soil pollution by using a battery of bioassay. Plant assay and earthworm assay were conducted to evaluate ecotoxicity o soils contaminated by heavy metals (cadmium and copper) and oil (BTEX compounds, toluene). Test plants were Zea may, Triticum aestivum, Cucumis sativus, and Sorghum bicolor. The presence of heavy metals decreased the seedling growth. Cucumis sativus and Sorghum bicolor seemed to be good indicator plants which are sensitive to heavy metal pollution as well as BTEX contamination. An earthworm bioassay was performed to predict the ecotoxicity in toluene-contaminated soils, based on a simple contact method. Perionyx excavatus was adopted as a test earthworm species, and the severity of response increased with increasing toluene concentration. The present study demonstrated that ecotoxicological methods could be a quantitative approach to evaluate contaminated soils.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.138-146
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• 2019

Objectives : This study examined the association between depression and survival time in terminal cancer patients admitted to the palliative care unit. Emotional problems are important for terminal cancer patients in the palliative care unit, and evaluation of patients' depression plays an important role in treatment planning. Methods : From October 2015 to August 2018, we conducted a retrospective study of 291 terminal cancer patients admitted to a palliative care unit at a university hospital and evaluated depression with PHQ-9 at admission. Of the 291 patients, 146 (50.2%) completed PHQ-9 but 145 (49.8%) were not evaluated due to loss of consciousness or rejection. Results : 4-week survival rate in the Kaplan-Meier survival analysis were 45.4% in the non-depressed group (PHQ-9<10) and 18.7% in the depressed group (PHQ-9≥10). According to the severity of depression, in the Cox proportional hazard model, the risk of mortality in moderate, moderately sever and severe group was 2.778, 1.882 and 3.423 times higher than minimal group, respectively. Conclusions : Of the patients with terminal cancer who were admitted to the palliative care unit, the survival time was shorter in the depressed group than in the non-depressed group. Further research is needed to determine if treatment of depression increase the survival in terminal cancer patients.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1260-1265
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• 2003

Purpose : In 1970, the Berlin-Frankfurt-Munster(BFM) group introduced an intensification therapy after remission induction to reduce relapse of acute lymphoblastic leukemia(ALL) in childhood. Delayed intensification(DI) phase has been included for treatment of ALL in our hospital since the mid-1990s. The purpose of this study is to evaluate the outcome with vs. without DI phase and the outcome with two vs. one DI phase for intermediate risk patients. Methods : One hundred and thirty nine children with ALL who were treated at the Department of Pediatrics of Wonju Christian Hospital and Yonsei University Medical Center between March, 1990 and July, 2002 were analysed retrospectively. Results : Thirty-eight patients were treated with a DI phase, and 101 patients were treated without a DI phase. Among the DI patients, seven patients were treated with a double DI phase. Five-year overall survival(OS) in the low, intermediate, and high risk groups were 68%, 66% and 58%, respectively. 5-year OS in DDI, DI, and control were 95%, 86% and 40%, respectively. In the low risk group, 5-year event free survival(EFS) in DI, and control were 94% and 58%, respectively. Conclusion : Delayed intensification improved EFS on childhood ALL in all risk groups.