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      • SCOPUSKCI등재

        대장직장 종양에 대한 내시경 점막하 절제술의 연대순 임상 결과와 학습 곡선

        이상민 ( Sang Min Lee ),김은수 ( Eun Soo Kim ),박경식 ( Kyung Sik Park ),조광범 ( Kwang Bum Cho ),김동춘 ( Dong Choon Kim ),강유진 ( Yu Jin Kang ),이유진 ( Yoo Jin Lee ),이정민 ( Jung Min Lee ),최은성 ( Eun Sung Choi ),최재혁 ( Ja 대한소화기학회 2014 대한소화기학회지 Vol.64 No.4

        Background/Aims: Endoscopic submucosal dissection (ESD) is an effective procedure for en-bloc curative resection of the colorectal tumor. As it requires high technical skills and experience in therapeutic endoscopy, it is important to understand learning curve of ESD technique. The aim of this study was to retrospectively describe the clinical results of ESD and to evaluate learning curve for the ESD of colorectal tumors. Methods: A total of 90 patients with 90 colorectal neoplasms, who had undergone ESD at a tertiary referral hospital from July 2009 to December 2012, were enrolled. The ESD was performed by a single endoscopist. All ESD cases were divided into three periods: first, cases 1-30; second, cases 31-60; and third, cases 61-90. Results: The en-bloc resection rates in third period (100%) was significantly higher than that of the first (93.3%) and second period (80%) (p=0.025). The perforation rate in third period (0%) also significantly decreased compared with that of the first (13.3%) and second period (20%) (p=0.032). To calibrate the difference of tumor size among periods, proficiency was calculated, as the procedure time per specimen area (min/cm2). The proficiency in third period (4.3) was significantly shorter than that of the first (16.8) and second period (10.2) (p=0.004). Conclusions: The learning curve of colorectal ESD in our study shows that at least 60 cases of ESD have to be conducted to acquire sufficient skill of degree without perforation. (Korean J Gastroenterol 2014;64:198-205)

      • KCI등재

        소동물 폐종양의 정량적 개선을 위한 내부 움직임 평가

        유정우,우상근,이용진,김경민,김진수,이교철,박상준,유란지,강주현,지영훈,정용현,김병일,임상무,Yu, Jung-Woo,Woo, Sang-Keun,Lee, Yong-Jin,Kim, Kyeong-Min,Kim, Jin-Su,Lee, Kyo-Chul,Park, Sang-Jun,Yu, Ran-Ji,Kang, Joo-Hyun,Ji, Young-Hoon,Chung, Y 한국의학물리학회 2011 의학물리 Vol.22 No.3

        이 연구에서는 폐종양의 정량적 개선을 위하여 분자체를 이용하여 내부 움직임을 측정하고 평가된 데이터를 기반으로 소동물 PET 영상내의 폐종양을 국소화하고자 하였다. 소동물 폐 영역의 내부 움직임은 방사성물질을 흡착한 분자체를 이용하여 소동물 폐 영역에 부착함으로써 구현하였다. 폐 영역의 내부 움직임 표적으로 사용된 분자체는 약 37 kBq의 Cu-64를 흡착시켜 폐종양을 모사하였다. 소동물 PET 영상은 Siemens Inveon 스캐너를 이용하여 획득하였으며 외부 움직임 데이터는 트리거 생성 장치인 BioVet을 이용하였다. SD-Rat PET 영상은 $^{18}F$-FDG 37 MBq/0.2 mL을 미정맥으로 주사하고 60분 후 20분간 데이터를 획득하였다. 리스트모드 데이터의 각 선응답은 외부 트리거 장치에 의해 획득된 트리거신호를 이용하여 2 bin에서 16 bin으로 사이노그램을 획득하였다. 획득된 사이노그램 데이터는 OSEM 2D 알고리즘을 이용하여 4회의 반복으로 재구성하였다. 종양의 정량적 분석을 위한 PET 영상은 종양을 묘사한 분자체 영역에 관심영역을 설정하고 계수와 SNR 그리고 FWHM을 이용하여 평가하였다. 움직임 표적으로 사용된 분자체의 크기는 $1.59{\times}2.50mm$이었으며, 기준 영상으로 획득한 체외 분자체 수직 및 수평 FWHM은 $2.91{\times}1.43mm$이었다. 정적영상과 4 bin 그리고 8 bin 영상에서의 수직 FWHM은 각각 3.90 mm, 3.74 mm, 3.16 mm이었으며 수평 FWHM은 각각 2.21 mm, 2.06 mm, 1.60 mm이었다. 정적영상, 4 bin, 8 bin, 12 bin 그리고 16 bin의 계수 값은 각각 4.10, 4.83, 5.59, 5.38, 5.31이었다. 정적영상, 4 bin, 8 bin, 12 bin 그리고 16 bin의 SNR은 4.18, 4.05, 4.22, 3.89, 3.58이었다. FWHM은 게이트 수의 증가에 따라 계속 향상됨을 확인하였다. 그러나 계수 값과 SNR은 게이트 수의 증가에 따라 계속 향상되지 않고 특정 bin 수에서 가장 높은 값을 보여 소동물 폐 영역에서의 종양 영상화시 SNR의 손실을 최소화하면서 향상된 계수 값을 얻을 수 있는 게이트 수를 획득하였다. 내부 움직임 측정은 최적화된 종양 국소화 영상을 획득할 수 있으며 외부 움직임 모니터링 시스템을 사용하지 않고 장기별 움직임 예측 모델링을 위한 유용한 방법이 될 것으로 기대된다. The purpose of this study was to estimate internal motion using molecular sieve for quantitative improvement of lung tumor and to localize lung tumor in the small animal PET image by evaluated data. Internal motion has been demonstrated in small animal lung region by molecular sieve contained radioactive substance. Molecular sieve for internal lung motion target was contained approximately 37 kBq Cu-64. The small animal PET images were obtained from Siemens Inveon scanner using external trigger system (BioVet). SD-Rat PET images were obtained at 60 min post injection of FDG 37 MBq/0.2 mL via tail vein for 20 min. Each line of response in the list-mode data was converted to sinogram gated frames (2~16 bin) by trigger signal obtained from BioVet. The sinogram data was reconstructed using OSEM 2D with 4 iterations. PET images were evaluated with count, SNR, FWHM from ROI drawn in the target region for quantitative tumor analysis. The size of molecular sieve motion target was $1.59{\times}2.50mm$. The reference motion target FWHM of vertical and horizontal was 2.91 mm and 1.43 mm, respectively. The vertical FWHM of static, 4 bin and 8 bin was 3.90 mm, 3.74 mm, and 3.16 mm, respectively. The horizontal FWHM of static, 4 bin and 8 bin was 2.21 mm, 2.06 mm, and 1.60 mm, respectively. Count of static, 4 bin, 8 bin, 12 bin and 16 bin was 4.10, 4.83, 5.59, 5.38, and 5.31, respectively. The SNR of static, 4 bin, 8 bin, 12 bin and 16 bin was 4.18, 4.05, 4.22, 3.89, and 3.58, respectively. The FWHM were improved in accordance with gate number increase. The count and SNR were not proportionately improve with gate number, but shown the highest value in specific bin number. We measured the optimal gate number what minimize the SNR loss and gain improved count when imaging lung tumor in small animal. The internal motion estimation provide localized tumor image and will be a useful method for organ motion prediction modeling without external motion monitoring system.

      • 질의문 키워드의 가중치 부여 방법을 이용한 정답 문서 순위화 시스템

        강유환,안영민,서영훈 충북대학교 컴퓨터정보통신 연구소 2005 컴퓨터정보통신연구 Vol.13 No.1

        본 논문에서는 자연어로 된 질의문에 대한 키워드 추출 및 가중치 부여 방법을 이용하여 정답 문서를 상위로 순위화하는 방법을 제안한다. 정답 문서를 상위로 순위화하기 위해 자연어 질의문과 정답 문서에서 나타나는 키워드의 특성을 분석하고, 색인어로써 중요한 역할을 할 수 있는 키워드를 다양한 형태로 추출한 후, 추출된 키워드에 차별화된 가중치를 부여한다. 끝으로 문서에 나타난 키워드의 출현 횟수와 문서 가중치를 이용하여 문서를 순위화한다. 실험에서는 20개의 질의문에 대해 상위 5위 안에 들어 있는 정답 문서의 수를 측정하였다. 실험결과 상위 5위 안에 들어 있는 정답 문서의 평균 개수는 3.05개로 키워드의 출현횟수와 키워드의 근접상을 이용한 방법보다 높은 성능 향상을 보였다. This paper describes a method of weighting keywords in the question that is written in a natural language for ranking answer documents. We extract keywords from the question using characteristic of question and keywords that are used in answer documents. And we assign differentiated weight to each keyword. Finally, we rank documents in order that answer documents can be ranked in high position using frequency of keywords and weight of documents. In experiment, we tested the number of answer documents that are ranked in top 5 for 20 questions. Experimental results show that the average number of answer documents that are ranked in top 5 was 3.05 and the accuracy of the proposed method was improved comparing with the existing method using frequency and proximity of keywords.

      • KCI등재

        지연성 운동장애와 양성, 음성 정신분열병 환자에서의 인지기능 장애

        유범희,김지혜,배주미,이강욱,우종민,김승태 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

        저자들은 정신분열병 환자에서 양성, 음성 증후군에 따라 각각 특징적으로 어떤 인지기능의 장애를 보이는지 알아보며, 또 지연성 운동장애의 존재 여부가 인지기능에 어떤 영향을 미치는지 조사해보고자 지연성 운동장애 환자 31명과 대조군 32명에게 PANSS 검사를 시행하였고, 인지기능 검사로는 KWIS 검사와 Grooved Pegboard test, Trail making test A/B, Wisconsin card sorting test, Wecshler memory scale을 시행하였다. 그 결과 다음과 같은 성적을 얻었다. 1) KWIS 지능검사상 이해 소검사에서 양성 증후군 환자들이 음성 증후군에 비해 우수한 수행도를 보였으며 빠진 곳 찾기 소검사에서는 지연성 운동장애가 없는 집단이 있는 집단에 비해 우수한 수행도를 보였다. 2) Trail making test A형에서 양성 정신분열병 환자 집단이 음성 정신분열병 환자 집단에 비해 전반적으로 빠르고 효율적인 수행을 보였다. 3) 그밖의 다른 인지기능 검사상에서는 양성, 음성 정신분열병과 지연성 운동장애 유무에 따른 검사 결과의 차이는 보이지 않았다. 결론적으로 음성 증후군 환자들의 경우 양성 증후군에 환자들에 비해 실행 기능과 같은 전두엽 기능의 장애와 기억 능력의 저하가 좀더 분명하게 나타나 음성 증상과 인지기능 장애 사이에 통계적으로 의미있는 상관관계가 있는 것으로 나타났다. 반면 지연성 운동장애의 경우는 음성 증후군과 함께 나타날 때만 현실 검증력, 주의력의 저하가 두드러져서 지연성 운동장애 자체만으로 인지기능의 장애가 유발된다고 보기는 어려웠다. Objective : The goal of this study was to examine cognitive dysfunctions in positive and negative schizophrenic patients and investigate the effect of tardive dyskinesia on cognitive dysfunctions in them. Methods : Thirty two schizophrenic patients with tardive dyskinesia and thirty two schizophrenic patients without tardive dyskinesia as a control group were selected from psychiatric inpatients at a lunatic asylum and the cognitive dysfunctions of these patients were assessed with some neuropsychological tests including KWIS test, Grooved Pegboard test, Trail making test A and B, Wisconsin card sorting test, and Wechsler memory scale test. From these patients, we classified eighteen schizophrenic patients as a positive syndrome group and twenty five patients as a negative syndrome group with positive and negative syndrome scale and compared the results of neuropsychological tests between these two groups. Results : Patients without tardive dyskinesia showed better performances than those with tardive dyskinesia on picture completion subtest of KWIS. Positive schizophrenic patients showed better performances than negative schizophrenic patients on comprehension subtest of KWIS and trail making test A. Conclusion : Negative schizophrenic patients showed frontal lobe dysfunction and more memory impairment than positive schizophrenic patients. In conclusion, negative syndrome of schizophrenia is significantly associated with cognitive dysfunctions although tardive dyskinesia is not.

      • KCI등재후보

        Immunohistochemical study on the expression of calcium binding proteins (calbindin-D28k, calretinin, and parvalbumin) in the cerebral cortex and in the hippocampal region of nNOS knock-out(−/−) mice

        Yu Jin Cho,Jae Chul Lee,Bong Gu Kang1,2,Jaeyeol An,Hyeon Suk Song1,2,Onju Son,Do-Hyun Nam,Choong Ik Cha,Kyeung Min Joo 대한해부학회 2011 Anatomy & Cell Biology Vol.44 No.2

        Nitric oxide (NO) modulates the activities of various channels and receptors to participate in the regulation of neuronal intracellular Ca2+ levels. Ca2+ binding protein (CaBP) expression may also be altered by NO. Accordingly, we examined expression changes in calbindin-D28k, calretinin, and parvalbumin in the cerebral cortex and hippocampal region of neuronal NO synthase knockout(−/−) (nNOS−/−) mice using immunohistochemistry. For the first time, we demonstrate that the expression of CaBPs is specifically altered in the cerebral cortex and hippocampal region of nNOS−/− mice and that their expression changed according to neuronal type. As changes in CaBP expression can influence temporal and spatial intracellular Ca2+ levels, it appears that NO may be involved in various functions, such as modulating neuronal Ca2+ homeostasis, regulating synaptic transmission, and neuroprotection, by influencing the expression of CaBPs. Therefore, these results suggest another mechanism by which NO participates in the regulation of neuronal Ca2+ homeostasis. However, the exact mechanisms of this regulation and its functional significance require further investigation.

      • CMOS 전압표준을 이용한 온도보상 전류표준 회로

        양한유,홍국태,정강민 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.2

        본 연구는 외부조건의 영향을 적게 받고 일정한 전류를 발생시켜 주는 CMOS 전류표준 회로를 설계하였다. 이 회로에서 기존에 통상 사용되어 왔던 PTAT 전압원 대신에 특히 온도변화에 독립적인 구조로서 부동전압원에 CMOS 전압표준을 사용한 구조를 제시하였다. 이로서 회로의 정확성, 간결성을 향상시킬수 있다. 시뮬레이션을 통하여 회로의 작동을 검증하고 성능을 토의 하였다. In this work, a CMOS current reference circuit is designed, which is independent of variations of external parametters. A circuit configuration using CMOS voltage reference is suggested and it is shown that this circuit is less sensitive, especially to the temperature variations, compared to the PTAT voltage source. Through simulations, the operation of the circuit is verified and its performance is discussed.

      • KCI등재

        Hop Extract Produces Antinociception by Acting on Opioid System in Mice

        박수현,심윤범,Yu-Jung Kang,김성수,Chea-Ha Kim,Su-jin Kim,Jee-Young Seo,Su-Min Lim,서홍원 대한약리학회 2012 The Korean Journal of Physiology & Pharmacology Vol.16 No.3

        In the present study, the antinociceptive profiles of hop extract were characterized in ICR mice. Hop extract administered orally (from 25 to 100 mg/kg) showed an antinociceptive effect in a dose- dependent manner as measured in the acetic acid-induced writhing test. Antinociceptive action of hop extract was maintained at least for 60 min. Moreover, cumulative response time of nociceptive behaviors induced with intraplantar formalin injection was reduced by hop extract treatment during the 2nd phases. Furthermore, the cumulative nociceptive response time for intrathecal injection of substance P (0.7 μg) or glutamate (20 μg) was diminished by hop extract. Intraperitoneal pretreatment with naloxone (an opioid receptor antagonist) attenuated antinociceptive effect induced by hop extract in the writhing test. However, methysergide (a 5-HT serotonergic receptor antagonist) or yohimbine (an α2-adrenergic receptor antagonist) did not affect antinociception induced by hop extract in the writhing test. Our results suggest that hop extract shows an antinociceptive property in various pain models. Furthermore, the antinociceptive effect of hop extract may be mediated by opioidergic receptors, but not serotonergic and α2-adrenergic receptors.

      • KCI등재

        남성화 암쥐의 모리스 수중 미로 수행력 : 성에 따른 공간기억력과 테스토르테론 효과의 차이

        신성현,박제민,정우영,박문일,서유나,김성곤,강철중 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.5

        Objectives : It is widely accepted that gonadal steroids are involved in organization and activation of sexual dimorphism in the brain areas related with spatial leaming. This study aimed to test the following hypothesis : 1) spatial memory is affected by sex, 2) this difference is related with brain differentiation by exposure to testosterone in the neonatal period, and/or 3) the sexual difference of spatial memory is the result of the interaction between organization of sexual dimorphism in the brain and the circulating testosterone after growing up. Methods : Testosterone enanthate 100 ㎍, ('androgenized') orvehicle ('control') was randomly administered to 28 female and 25 male rat pups within 24 hour of birth. The escape latencies (EL) in Morris water maze were measured in 15 and 16 week of age with vehicle ('baseline') and with 10 μmol/kg of testosterone ('with testosterone'), respectively. Each session Consis-ted of 10 trials, and means of the last 5 trials were analyzed. Results : The baseline EL of the males were significantly shorter than females regardless ofneonatal exposure to testosterone. With testosterone, EL of the androgenized females were significantly shorter than control females and comparable to those of males. Conclusion : Neonatal exposure to testosterone in female rats may develop a tesosterone-dependent male-like spatial leaming system.

      • ^(7)Li, ^(87)Rb과 ^(27)Al NMR을 이용한 (K_(1-x)Li_(x))_(2)SnCl_(6), (K_(1-x)Rb_(x))_(2)SnCl_(6)와 K_(2)SnCl_(6):Al^(3+)의 상전이 근처에서의 결정 동력학 연구

        김복수,김영훈,강재필,백아영,차유정,김민경,서용문,송승기 명지대학교 자연과학연구소 2004 자연과학논문집 Vol.23 No.-

        K_(2)SnCl_(6)는 antifluoride계에 속하는 결정으로서 K_(2)SnCl_(6)에 Li^(+)를 첨가하여 ^(7)Li 핵자기공명(NMR)을 측정하여 동형(isomorphic) 혼합결정(K_(1-x)Rb_(x))_(2)SnCl_(6)와 비동형(nonisomorphic) 혼합결정 K_(2)SnCl_(6):Al^(3+)에서의 핵자기공명(NMR), ^(87)Rb NMR과 ^(27)Al NMR의 측정값과 비교하였다. Rb^(+) 이온은 K_(2)SnCl_(6)의 K^(+)이온을 대신해 동형 결정을 이루며, Al^(3+)이온은 Sn^(4+)이온을 대치하면서 비동형 결정을 이루는데 Li^(+)이온 또한 K^(+)이온을 대신하는 동형 혼합결정과 유사한 결과 값을 얻을 수 있었다. 이 연구 결과는 종래의 Cl-NQR 연구 결과와 비교함으로서 K_(2)SnCl_(6)의 동력학적 특성과 구조 상전이 근처에서의 임계현상을 새로운 관점에서 볼 수 있는 가능성을 보여주었다. ^(7)Li, ^(87)Rb and ^(27)Al NMR have been investigated in the isomorphic and nonisomorphic impurity doped crystals (K_(1-x)Li_(x))_(2)SnCl_(6), (K_(1-x)Rb_(x))_(2)SnCl_(6) and K_(2)SnCl_(6):Al^(3+) as a supplementary to the previous Cl NQR studies in these crystals. The results yielded that the features of NMR spectra for both types of crystals are roughly in line with the systematic trends shown in the Cl NQR in these crystals, though the outstanding characteristics exhibited in the Cl NQR become in the case of the NMR of the doped impurities in crystals somewhat weakend. This is due to the degradation of the role of the local field from the main hamiltonian in NQR to the subsidiary in NMR. Each NMR result of the iso/nonisomorphic crystals has been analyzed in terms of the 'impurity induced dynamic lattice defects' for K_(2)SnCl_(6):Al^(3+) and the 'static primary impurity effects' for (K_(1-x)Rb_(x))_(2)SnCl_(6) and (K_(1-x)Li_(x))_(2)SnCl_(6) respectlvely.

      • KCI등재

        계면활성제 함유 인지질 나노입자의 초가변성 연구

        신지영,오유경,강민정,권경애,김종국 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.3

        This study was aimed to formulated various phospholipid nanoparticles composed of different surfactants and to evaluate the deformability of the phospholipid vesicles as candidates of useful ultradeformable nanoparticles. In vitro deformability of the hospholipid nanoparticles was studied using an extruder under a certain pressure. The sizes of phospholipid nanoparticles, passed volumes, and concentrations of the phospholipids in suspensions before and after extrusion were measured. The deformability indexes were estimated by using passed volumes, sizes of phospholipid nanoparticles and concentrations of phospholipids. Conventionl liposomes, placed under a certain pressure of an extruder, showed no passed volume indicating little deformability. Similar to conventional liposomes, phospholipid nanoparticles containing surpactants such as sodium taurcholate, Myrj 45, or Myrj 53 showed little deformability. In contrast, phospholipid nanoparticles composed of Tween 20, triton X-100, or sodium deoxycholate showed higher deformability indexes than others. Taken together, the deformability of phospholipid nanoparticles could be significantly affected by the type of surfactants. Moreover, these results suggest that the deformability of phospholipid nanoparticles could be modulated by surfactants.

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