Evaluating the efficacy of secondary transurethral resection of the bladder for high-grade Ta tumors

이경채,정승환,유상현,구자현 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.1

Purpose: The need for secondary transurethral resection of the bladder (re-TURB) in patients with high-grade Ta tumors has not been assessed. This study aimed to compare the outcomes of patients with high-grade Ta tumors who did and did not undergo re-TURB. Materials and Methods: This study used data from the Seoul National University Prospectively Enrolled Registry for Urothelial Cancer–Transurethral Bladder Tumor Resection (SUPER-UC-TURB). Patients with high-grade Ta tumors who underwent TURB between March 2016 and December 2019 were included. Following the initial TURB, if the pathology results showed a tumor grade higher than high-grade Ta, re-TURB was performed according to the surgeon’s recommendation. The recurrence-free survival rate was assessed by Kaplan–Meier analysis and Cox regression analysis between patients who did and did not undergo re-TURB. Results: In total, 187 patients with high-grade Ta who underwent initial TURB were included, of whom 115 underwent re-TURB and 72 did not. Patients in the re-TURB group had a significantly higher 2-year recurrence-free survival rate than did those in the no re-TURB group (81.3% vs. 60.1%; p=0.005). Whether patients underwent re-TURB was a significant predictor of the risk of bladder cancer recurrence in both the univariate (HR, 0.52; 95% CI, 0.27–0.98; p=0.044) and multivariate (HR, 0.41; 95% CI, 0.19–0.97; p=0.041) analysis. Conclusions: The risk for bladder cancer recurrence was increased, and the 2-year recurrence-free survival was significantly decreased, in patients with high-grade Ta tumors who did not undergo re-TURB. Thus, re-TURB is beneficial in patients with high-grade Ta bladder cancer.

스테레오 비젼에 의한 생체표면 3차원 복원의 최적화 연구

이경채,이언석,Lee, Kyungchai,Lee, Onseok 대한전기학회 2017 전기학회논문지 Vol.66 No.1

Unlike regular images, there is no ground truth for bio surface images. Result of biosurface imaging is not only significantly affected by the environment and the condition of the bio surface, it requires more detailed expression than regular images. Therefore, unlike algorithms tested on regular images, studies on bio surface images requires a highly precise optimization process. We aim to optimize the graph cut algorithm, known to be the most outstanding among the stereo visions, by considering baseline, lambda, and disparity range. Optimal results were in the range of 1~10 for lambda. The disparity ranged from -30 to -50, indicating an optimal value in a slightly higher range. Furthermore, we verified the tested optimization data using SIFT.

보육시설 평가인증제에 관한 보육시설 종사자들의 인식 연구

이경채 한국보육학회 2004 한국보육학회지 Vol.4 No.1

The purpose of this study is to examine opinions of teachers working for a field of chile-care facilities and directors who are the chiefs of facilities, in order to arrange for a firm stand of more effective evaluation certification system, by reflecting opinions being derived from a job site, together with more effective enforcement of Evaluation Certification System of Day Care Center. The main starting point of this study is not to have attained a survey of opinions of teacher for Day Care Center who are actually being in a filed, about the evaluation certification system of Day Care Center, and the second is to allow the smooth enforcement to be attained if "Evaluation Certification System of Day Care Center" is tried to be carried out on the basis of the national policy. This study targeted directors and teachers for the national, public, and private Children"s Homes located in Gyeonggido area, and widely distributed to collect this questionnaire for about three weeks from March 10 to 29 of 2003. It used total 208 sheets for the final statistical processing. It used SPSSWIN 10.0 that is the statistical program, aiming at the statistical processing. As a result of studying, it was shown that teacher at a field related to child care were wholly feeling keenly the necessity for evaluation certification system of Day Care Center, and concerning about problems to be caused by the enforcement method and the operation process for the system. In other words, it was shown to wholly agree with a point of a system necessary for the truly qualitative development, while worrying about whether it will remain in a formality, leading to only overweight of duties, due to the evaluation for evaluation and the system for system. It is thought that more effective qualitative enhancement in Day Care Center will be able to be promoted, in case of discussing what is called the evaluation certification system of Day Care Center, amid mutually harmonious relationship through the institutional and legal device of the national dimension, based on efforts and responsibilities of specialists and teacher in a filed for Day Care Center.

스테레오 비젼에 의한 생체표면 3차원 복원의 최적화 연구

이경채(Kyungchai Lee),이언석(Onseok Lee) 대한전기학회 2017 전기학회논문지 Vol.66 No.2

Unlike regular images, there is no ground truth for bio surface images. Result of biosurface imaging is not only significantly affected by the environment and the condition of the bio surface, it requires more detailed expression than regular images. Therefore, unlike algorithms tested on regular images, studies on bio surface images requires a highly precise optimization process. We aim to optimize the graph cut algorithm, known to be the most outstanding among the stereo visions, by considering baseline, lambda, and disparity range. Optimal results were in the range of 1~10 for lambda. The disparity ranged from -30 to -50, indicating an optimal value in a slightly higher range. Furthermore, we verified the tested optimization data using SIFT.

간내담석의 화학적 용해에 대한 체외 실험적 연구

이경효,김영구,이종범,심형진,광병국,김건상,주상신,채수경,박현미 대한영상의학회 1995 대한영상의학회지 Vol.33 No.6

Purpose : The in vitro dissolution of intrahepatic stones was evaluated using the various solvent mixtures.Materials and Methods : Sixty four intrahepatic stones from 16 patients were used. Four kinds of solvent mixtures(No.1 = basic buffer + EDTA, No.2 = 1 + Sulfobetain-12, No.3 = 3 + N-acetylcysteine, No.4 = 3 + urea) were used.Dissolution rates were determined by measuring the weight loss of stones after 6, 12, 24, 48 hours incubationperiods, respectively. Results : The highest dissolution rates in dissolving intrahepatic stones were achievedwith No.4 solvent mixture(1% W/V EDTA/80mM, Sulfobetain-12/1M, urea, pH 9.5). Conclusion : Intrahepatic stonescould be largely dissolved up to about 70% of their initial weight after 48 hours incubation period in vitro.

에타놀, 고온 생리 식염수 및 고농도 식염수를 백서 간에 주입 후 조직학적 변화

채수경,이종범,이경효,주상신,이화연,임상준,송인섭,이용철,박언섭 대한영상의학회 1997 대한영상의학회지 Vol.36 No.2

Purpose : The purpose of this study was to evaluate the degree of liver injury after injection of ethanol, hot normal saline and hot hypertonic saline into normal rat liver. Materials and Methods : Sixty white rats weighing 200-300g were used. There were three groups (ethanol, hot normal saline, and hot hypertonic saline), and these were divided into subgroups (5 rats in each) according to amount of injected material and duration. Under ether anesthesia, each drug (ethanol -0.05ml, 0.1ml, 0.2ml ; hot normal saline -0.1ml, 0.2ml, 0.4ml ; hot hypertonic saline -0.1ml, 0.2ml, 0.4ml) was introduced directly into the liver. Pathologic specimens were obtained 7 and 14 days after injection. Results : With regard to histologic change after 7 days, the ethanol group showed less tissue damage such as coagulation necrosis and inflammatory infiltration-than the hot saline group. There was however, no significant difference among the three groups in tissue damage at 14 days. Nor was there any significant histologic difference between the different saline concentration groups. Conclusion : Histologically, there was no significant difference among the three groups in tissue damage at 14 days, and it is suggested that this is due to irreversible change in damaged tissue. Tissue damage was caused mainly by the high temperature of saline rather than by high osmolarity.

레티노산 함유 폴리락탄산 나노입자의 제조 및 약물 방출

채지만,이경만,김인숙,이용복,신상철,오인준 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.5

To develop an intravenous delivery system of all-trans retinoic acid (ATRA) for the cancer therapy, poly(L-lactic acid) nanoparticles were prepared and characterized. Emulsification-solvent evaporation method was chosen to prepare submicron sized nanoparticles. Spherical nanoparticles less than 200 nm in diameter with narrow size distribution were pre-pared, and the entrapment efficiency of drug was more than 95%. The endothermic peak at 183°C and X-ray crystallographic peak of ATRA appeared in the nanoparticle system, suggesting the inhibition of crystallization of ATRA by polymer adsorption during the precipitation process. ATRA was released at 37℃ for 60 days and the release rate was dependent on the concentration of drug incorporated in the nanoparticles. While ATRA was unstable in the light, it was very stable at 4℃. These results suggest the usefulness of PLA nanoparticles as a sustained and prolonged release carrier for ATRA.

심전도 신호 처리를 위한 기저함수 추출에 관한 연구

李秉采(Byung-Chae Lee),鄭基森(Kee-Sam Jeong),尹亨老(Hyung-Ro Yoon),李景中(Kyoung-Joung Lee),朴光里(Kwang-Li Park),李田(Jeon Lee) 대한전기학회 2004 전기학회논문지 D Vol.53 No.4

KR-30816이 심근 세포에서 활동 전위 및 ATP-Sensitive potassium Channel에 미치는 효과

이경석,고재기,곽용근,채수완 대한순환기학회 1994 Korean Circulation Journal Vol.24 No.6

볼트 미끄럼을 고려한 칼럼-트리 형식 철골모멘트 접합부의 회전성능평가

이경구,채봉수,김선웅 한국방재학회 2015 한국방재학회논문집 Vol.15 No.1

In this paper, the rotation capacity of a column-tree type steel moment connection is analytically investigated with the consideration ofbolt-slip effects. To this end, nine specimens with the column-tree type steel moment connection were precisely modeled and materialand geometric nonlinear finite element analyses considering the bolt-slip, which the span-to-depth ratio and the beam depth are variablesin this study, were conducted. Its chord yield rotation capacity is larger than welded steel moment connection and its bearingforce redistribution occurs by the bolt-slip. As the span-to-depth ratio is getting larger, the flexural resisting capacity in the beginningpoint of the bolt-slip is decreased while the magnitude of the stiffness reduction and the yield rotation capacity is increased. Therefore,it can be found that a governing factor to determine the rotation capacity of the column-tree type steel moment connection is thespan-to-depth ratio. As a result, in order to achieve the reasonable seismic performance evaluation of the Korean existing column-treetype steel moment connection, the moment-rotation relationship considering the bolt-slip should be applied to. 본 연구에서는 비선형 유한요소해석을 통해 볼트 미끄럼을 고려한 칼럼-트리형식 철골모멘트 접합부의 회전성능평가을 평가하였다. 이를 위해 칼럼-트리형식 접합부 상세를 정밀하게 모델링하고 보경간 대 보춤 비 및 보 사이즈를 변수로 하여 볼트 미끄럼을 고려한 재료 및 기하학적 비선형 유한요소해석을 수행하였다. 볼트 미끄럼의 발생으로 인해 접합부의 항복회전각이 커지며, 접합부의 내력재분배가 발생함을 확인하였다. 보경간 대 보춤 비가 커질수록 강성저감 및 항복회전각은 커지고, 볼트 미끄럼이 발생하는 시점에서의 휨저항력은 낮아짐을 확인하였다. 따라서 칼럼-트리형식 접합부의 회전성능을 결정하는 지배요소는 보경간 대 보춤 비임을 알 수 있었다. 결론적으로, 국내 기존 철골모멘트골조의 합리적인 내진성능평가를 위해서는 볼트 미끄럼을 반영한 모멘트-회전각 관계를 적용하여야한다.