OcuLarsol(R)의 전방 관류가 각막내피세포에 미치는 영향

이정탁 ( Jeong Tak Lee ),송종석 ( Jong Suk Song ),김효명 ( Hyo Myung Kim ),김기산 ( Ki San Kim ) 대한안과학회 2003 대한안과학회지 Vol.44 No.2

Partial Coherence Interferometry를 이용한 안축장의 측정

이정탁 ( Jeong Tak Lee ) , 송종석 ( Jong Suk Song ) , 김효명 ( Hyo Myung Kim ) 대한안과학회 2003 대한안과학회지 Vol.44 No.4

당귀와 구기자 에탄올 추출물의 피부 미백작용

황성연,이정탁,김영욱,김홍준,Hwang, Sung Yeoun,Lee, Jeong Tak,Kim, Yeong Uk,Kim, Hong Jun 대한한의학방제학회 2013 大韓韓醫學方劑學會誌 Vol.21 No.1

Objective : The purpose of this study was to investigate the synergistic effect of Angelicae gigantis Radix (AG) and Lycii fructus (LF) ethanol extracts on skin-whitening effects. Method : LFAG extracts were prepared by extracting with 80% ethanol. The efficacy of LFAG was judged by measurement of cell viability, tyrosinase activity, melanin production, tyrosinase and microphthalmia-associated transcription factor (MITF) expression in B16F10 murine melanoma cells by lipopolysaccharides (LPS) treatment. Results : Each extract (LF or AG) inhibited the tyrosinase activity in a dose-dependent manner. The co-treatment of LFAG extracts ($25{\mu}g/mL$ LF plus $25{\mu}g/mL$ AG) markedly suppressed the LPS-induced cellular tyrosine activity, melanin production, tyrosinase and MMP-1 expression in B16F10 murine melanoma cells. These suppressive effects were synergistically increased by their combination. Conclusions : With these observations, we suggest that the extracts from Lycii fructus and Angelica gigantis Radix could be potent natural materials for whitening skin.

고밀도 물질에 기인한 CT영상 화질저하 개선을 위한 Iterative MAR 알고리즘 적용의 유용성에 관한 연구

강지원(Ji Won Kang),조인완(In Hwan Jo),김현주(Hyeun Joo Kim),정우준(Woo Joon Jeong),고병근(Byeung Geun Go),이정탁(Jeong Tak Lee),유회성(Hoi Seong Yoo),유병헌(Byeong Heon Yoo) 대한CT영상기술학회 2016 대한CT영상기술학회지 Vol.18 No.2

Purpose: In this research we tried to know the limitation and how much IMAR algorithm useful is in the clinical field by the evaluation of image and ana lysis using image data from phatom research and clinical research which used the Iterative MAR(Metal Artifact Reduction) algorithm from Inc. C that chose the way to get the data through its own HU of the kinds of metal in the human body(Titanium:4.5g/cm³ Around 6500HU, Stainless steel:7.8g/cm³ Around 50000HU, Gold:19.3g/cm³ Over 100000HU). Materials and Methods : We made the phantom with the dense material used in the replacement arthroplasty(L-spine : Titanium, Hip joint : Stainless steel), made of platinum for aneurysm in cerebral vessels and gold for dental filling. Also we used these machines, Somatom Derinition Flash from Inc. 5 and 64-MDCT Discovery 750 HD from Inc. G. we had studied from 1st May to 31st Oct. in 2015 using the image data from the patients to visit the hospital for f/u test. We used Advantage workstation program for alnalysis. We chose the ROI sized 2mm at the same part of Black Streak artifact and White streak artifact to record the average of the CT value after measuring it 20 times. Calculating the attenuation number, using the CT value measured, we calculate the attenuation number for each machines as the percentage to know how much the attenuation decrease, then compared and analyzed that. We got the image data after scan and set the same WW/WL of image data through Advantage Workstation program for research about clinical image. After then two groups, one consists of 2 radiologists and another one consists of 3 radiology technicians, evaluate how much the artifact reduce and the factors deciding the image quality such as resoultion and contrast. Result : As a result of converting attenuation coefficient into a percentage in the phantom research, Black streak artifact and White streak artifact of GDC coil image with MAR algorithm were 94% and 51% but both of them of GDC coil image with IMAR algorithm were 1% and 37%. Both of them decreased by 93% and 14% each. In Titanium, Black streak artifact decreased by 6%, from 17% to 11% and White streak artifact decreased by 19%, from 21% to 2% after using IMAR algorithm instead of MAR. In stainless steel Black streak artifact decreased by 5%, from 7% to 2% and White streak artifact decreased by 27%, from 34% to 7%. According to this phantom research, GDC coil, titanitum, and stainless steel are evaluated ‘adequate’ which had 3points in most of categories. Gold is the only one evaluated ‘good’ which had 4points in most of categories. This is the result of using IMAR algorithm instead of WFBP in the clinical image research, after converting attenuation coefficient into a percentage. Black streak artifact decreased by 17%, from 24% to 7%, and White streak artifact decreased by 7%, from 9% to 2% in plantium(GDC coil). In gold for dental filling, Black streak artifact decreased by 23%, from 33% to 10%, and White streak artifact decreased by 25%, from 30% to 5%. Also in stainless steel, Black streak artifact decreased by 48%, from 52% to4%, and White streak artifact decreased by 45%, from 46% to 1%. According to the evlauation for clinical images, GDC coil, titanium, and Stainless got 4points which meant ‘good’ in most of categories. Gold evaluated ‘adequate’, 3points in most of categories. Condusion : IMAR algorithm is more useful to reduce metal artifact caused by dense material rather than MAR algorithm. Using IMAR algorithm can provide information of various kinds to tissue with less artifact around metal foreign body, so it will be much more helpful for accurate diagnois. 목적 : 본 연구에서 인체에 삽입된 금속의 물질별(Titanium :4.5g/cm³ Around 6500HU, Stainless steel:7.8g/cm³ Around 5000HU, Gold:19.3g/cm³ Over 100000HU)로 고유의 HU(Hounsfield Unit)값을 적용하여 Data를 얻는 방식인 S사의 Iterative MAR(Metal Artifact Reduction) 알고리즘을 팬텀 연구와 임상 연구를 시행하여 획득된 영상데이터를 이용하여 정량적 분석과 임상 영상평가를 통하여 IMAR 알고리즘 유용성과 더불어 제한점을 알아보고자 하였다. 대상 및 방법 : 임상에서 치료목적으로 사용하는 재료 중 정형 외과적 치환술 시 이용하는 고밀도(L-spine: Titanium), (Hip joint: Stainless steel)물질과 머리 혈관 동맥류의 시술을 위해 사용하는 Platinum성분의 고밀도 물질인 GDC coil, 치아 충전재로 사용하는 Gold(Dental filling)를 이용하여 자체 제작한 팬텀과 이를 토대로 적용한 임상연구의 순으로 진행하였다. 연구를 위해 이용한 장비는 S사의 Somatom Definition Flash와 G사의 64-MDCT Discovery 750 HD를 사용하였다. 임상연구는 2015년 5월 1일부터 10월31일까지 5개월간 추적검사를 위해 내원한 환자의 영상데이터를 이용하였다. 정량적 분석은 Advantage workstation 프로그램에서 Black streak artifact와 White streak artifact의 동일한 부위에 직경 2mm의 ROI를 그려 CT value값을 20회 씩 측정 후 평균 CT value값을 기록 하였다. 측정 CT value 값을 이용하여 감약계수로 환산 후 각 장비별 인공물 감소 정도를 백분율로 계산 후 비교 분석 하였다. 임상영상 연구는 스캔 후 획득한 영상 Data를 Advantage Workstation 프로그램을 이용하여 WW/WL을 동일하게 설정 한 후 영상의학과 전문의 2명, 방사선사 3명 등 총 5명의 관찰자가 5점 척도로 인공물의 감소 정도 및 영상의 화질 좌우인자인 해상도 및 대조도 등의 항목을 적용하여 평가하였다, 결과 : 팬텀연구에서 감약계수를 백분율로 환산한 결과 GDC Coil에서 Black streak artifact와 White streak artifact순으로 MAR는 94%, 51%, IMAR는 1%, 37%로 93%, 14% 감소되었다. Gold에서 MAR는 30%, 22%, IMAR는 24%, 16%로 둘 모두 6% 감소되었다. Titanium에서 MAR는 17%, 21%, IMAR는 11%, 2%로 6%, 19% 감소되었다. Stainless steel에서 MAR는 7%, 34%, IMAR는 2%, 7%로 5%, 27% 감소되었다. 팬텀 영상 평가는 GDC coil, Titanium, Stainless steel 모두 Adquate(3점)이 가장 많았고, Gold는 Good(4점)이 가장 많았다. 임상 영상 연구에서는 감쇠계수를 백분율로 환산한 결과 Platinum(GDC Coil)에서 WFBP는 24%, 9%, IMAR는 7%, 2%로 17%, 7% 감소되었다. Gold(Dental filing)는 WFBP 33%, 30%, IMAR 10%, 5%로 23%, 25% 감소되었다. Titanium은 WFBP 93%, 61%, IMAR 35%, 15%로 58%, 46% 감소되었다. Stainless steel은 WFBP 52%, 46%, IMAR 4%, 1%로 48%, 45% 감소되었다. 임상 영상 평가는 GDC Coil, Titanium, Stainless steel 모두 Good(4점), Gold는 Adquate(3점)이 가장 많았다. 결론 : 고밀도 물질에 의한 Metal Artifact를 기존의 MAR Algorithm 보다 IMAR Algorithm을 적용시켰을 때 보다 유용하게 감소시킬 수 있으며. IMAR는 Artifact가 감소된 금속구조물주변의 다양한 조직들의 정보를 제공할 수 있어 영상의학과 판독의와 임상의에게 정확한 진단을 결정하는데 많은 도움을 줄 수 있을 것으로 사료된다.

朝鮮朝 山林文學의 代表作家에 對하여 : 時調를 中心으로

이정탁 安東敎育大學 1975 論文集 Vol.8 No.1

According to poem, Si-jo, we can point out the reprensentative poets of forest school in Choseon Dynasty as following; Lee Hwang, Lee I, Seo Kyung-duk, Sung Hon, Jo Sik, Lee Jung-bo, Yun Sun-do Kweon Hyo-moon, Kim Chun-taek, Kim Kwang-uk, Bak In-ro, Im Ei-jik, Jung Chul, Maeng Sa-sung, Kim Sung-ki, Kim U-kyu, Kim Yu-ki Kim Su-jang, Kwun Ik-yung, Sin Hum, Yoo Sim-yung, Lee Hyun-bo, Jung Do-kyung, kim Su-ryum Cho Myung-ri, Lee Cha-sang, Kim Mun-kun, Kim Yeo-kuii, Ho Suk-kyun, An Min-yung, Kim Woen-te, Lee Myung-han, Yoon Yoo, Kim Jang-saeng, Kim Min-soon, Chang Kyung-sae, Lee Jung-jin, Song Jong-woen, Sung Choong, Kim Tae-suk, Kim Ku. The general points of like these forest poets of the forest school in Choseon Dynasty 1) stand aloof from the miserable learned or party strife and seclude themselves from the society and escape to the forest, 2) deplore the uncertainty of taking office and hide in the forest, 3) are almost learnedmen, writers or neo-Confucians. They had elevated the sensibility of the forest, enhanced their feelings, and had written many emotional poems.

寒山詩 一考

이정탁 安東大學 1991 安東大學 論文集 Vol.13 No.1

요컨대, <한산시>의 성립과정과 그 문학사적 의의는 무엇인가, 더욱 그것이 중국문학사에 있어서 여하한 위상을 지니는가 등에 대해 두서너가지 비견을 정리해 보고저 한다. 첫째, <한산시>는 철인의 시라고 할 수 있다. 둘째, 불교의 철리에 대한 중국인의 수용자세와 <한산시>의 의의에 대해 생각해 보고저 한다. 셋째, 생활탐구의 각도에서 당시를 고찰할 수가 있다.

時調韻律攷

이정탁 安東大學 1985 安東大學 論文集 Vol.7 No.1

The theory for the foot of Sijos is devided to two-the assertion of two foot in terms of phrase and the contention of four foot in terms of chapter. But I think that the foot of Sijos are the latter because clauses in Sijos are preffered to phrase. Every chapter in Pyong-sijos was constituted by four foot. The first chapters and the last chapters in Ut-sijos were retained by four foot at the same time as those in Sasol-sijos were constituted. However, we can find that, the foot in Sijos were varied in the middle chapters.