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백서의 척수허혈시 허혈시간에 따른 신경손상과 유전자발현의 변화에 관한 연구
권재영,박상인,류지흠 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.38 No.5
Background: Spinal cord ischemia initiates a deleterious cascade of biochemical events that ultimately result in an increased intracellular calcium concentration. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. For the further study of preventing neurological injury after spinal ischemia, the proper animal model is necessary. In this study we compared spinal ischemia time on neurologic and histopathologic outcome, and inflammatory gene expression in transient spinal ischemia. Methods : Rats were anesthetized with halothane, and divided into 4 groups: 12.5 minutes of spinal ischemia (Group 1), 15 minutes of spinal ischemia (Group 2), 17.5 minutes of spinal ischemia (Group 3), and 20 minutes of spinal ischemia (Group 4). Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. After spinal ischemia neurologic scores were assessed after 1, 3, 6, and 24 hours. After 24 hours, rats were euthanized and spinal cords were removed for histopathologic assessment and an assay of TNF- a and IL-1 mRNA. Results : The neurologic scores worsened according to the ischemia time. The histopathologic scores correlated well with the neurologic scores. The TNF- a and IL-1 mRNA expression results of group 2 were larger than those of group 1. There were no significant differences between group 2, group 3, and group 4. Conclusions: Inflammatory gene expressions are increased during transient spinal ischemia. After 15 minutes of ischemia, no further increase of mRNA expression was shown. The 15 minutes of spinal ischemia was sufficient for the spinal ischemic study in rats. (Korean J Anesthesiol 2000; 38: 904~ 909)
권재영,김시내,박은지,송종우,Kwon, Jaeyoung,Kim, Sinae,Park, Eungee,Song, Jongwoo 한국통계학회 2015 응용통계연구 Vol.28 No.5
우리나라는 세계적으로 배달음식 문화가 가장 많이 발달한 나라 중에 하나로 최근에는 일인가구의 증가와 배달앱 시장의 발달과 함께 그 성장 속도 또한 눈부시게 증가하고 있다. 따라서 배달음식 이용에 큰 영향을 미칠 것으로 예상되는 날씨와 날짜별 변수를 고려하여 시간대별 배달음식 이용건수를 예측함으로써 소비자와 생산자 모두에게 이익을 주는 예측모형을 찾고자 한다. 본 연구의 목적은 다양한 데이터마이닝 기법을 이용하여 2014년도 배달음식 통화건수를 예측하는데 있다. 예측에 사용되는 회귀 모형은 선형회귀모형, 랜덤 포레스트, 그래디언트 부스팅, 서포트 벡터 기계, 신경망, 로지스틱 회귀모형으로 총 6가지이다. 고려되는 배달음식 업종은 총 4가지(족발/보쌈정식, 중국음식, 치킨, 피자)로 크게 두 가지 방법을 이용하여 각 업종별 배달음식 이용건수를 예측하였다. 첫 번째 방법은 총 이용건수와 각 업종별 배달음식 이용비율을 곱하여 각 업종별 배달음식 이용건수를 예측하는 것이고, 두 번째 방법은 각 업종별 모형을 세워 각 업종별 배달음식 이용건수를 예측하는 방법이다. 최종적으로 선택된 모형은 방법 1에서는 신경망 모형과 선형회귀모형이며, 방법 2에서는 신경망 모형이었다. 방법 2보다는 방법 1로 구한 결과가 더 예측력이 좋은 것으로 나타났다. Food delivery services are well developed in the Republic of Korea, The increase of one person households and the success of app applications influence delivery services these days. We consider a prediction model for the food delivery service based on weather and dates to predict the number of food delivery services in 2014 using various data mining techniques. We use linear regression, random forest, gradient boosting, support vector machines, neural networks, and logistic regression to find the best prediction model. There are four categories of food delivery services and we consider two methods. For the first method, we estimate the total number of delivery services and the posterior probabilities of each delivery service. For the second method, we use different models for each category and combine them to estimate the total number of delivery services. The neural network and linear regression model perform best in the first method, this is followed by the neural network which is the best for the second method. The result shows that we can estimate the number of deliveries accurately based on dates and weather information.
소아의 중심정맥 카테터 삽관 위치에 따른 적절한 카테터 깊이
권재영 부산대학교 병원 암연구소 2008 부산대병원학술지 Vol.- No.24
Purpose: In pediatric patients, several studies have been undertaken to establish central venous catheter (CVC) tip optimal depth. Assessments of catheter tip position using chest radiography may be misleading, whereas transesophageal echocardiography (TEE) has been shown to accurately monitor catheter tip placement at the superior vena cava-right atrial (SVC-RA) junction. The aim of this study was to issue a guideline for ideal catheter insertion depth, from the right or left subclavian vein using TEE to confirm the position of the catheter tip. Subject and Methods: 178 pediatric patients undergoing surgery for congenital heart disease were studied. Positions of catheter tips were confirmed to be at the SVC-RA junction by TEE. Distance from the skin puncture site to the SVC-RA junction, weight, and age were recorded. Results: Distances measured were found to be highly correlated with patient weight. Catheter length was 3.941+ 0.179x weight using left subclavian vein, and 3.286 + 0.178x weight using right subclavian vein. Conclusion: The model proposed for the insertion of the evc tip in pediatric patients could be used to prevent inadvertent catheter tip placement into the atrium.
권재영,이효민 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.2
Excess tannin in drinks can lead to unpleasant astringent taste, pinking or browning, as well as a decreasein clarity. While protein precipitation method in which various proteins and synthetic polymers are added to inducetannin-protein complexation, followed by separation via sedimentation, is widely used for tannin removal, sedimentationtime can take up to few days. In this work, we present poly(ethylene glycol) (PEG)-based microgels embedded withmagnetic nanoparticles (MNP) as fining agents for effective adsorption and removal of tannins, using tannic acid (TA)as the model tannin. The PEG microgel with high surface area enables the tannins to effectively adsorb through hydrogen-bonding, and the incorporated MNP enables facile recovery of TA adsorbed microgel via magnetic decantation. We also demonstrate that the PEG microgel is reusable and the TA adsorbed can be also valorized into ellagic acid(EA) by simple base treatment of the TA adsorbed microgels.