• Journal of Digestive Cancer Research
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• 제5권1호
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• pp.50-54
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• 2017

Pancreatic neuroendocrine tumors are rare pancreatic neoplasms comprising 1-2% of all pancreatic tumors and typically present high attenuating mass on arterial and venous phase images, due to their rich capillary network. A 70-year-old South Korean female visited our hospital presenting with jaundice and dark urine color. She had received an operation for treatment of small bowel perforation seven years ago. On physical examination, icteric sclera was observed but otherwise unremarkable. Laboratory tests were abnormal liver function test and suspected obstructive jaundice. Computed tomography revealed 4 cm sized cystic mass lesion with homogeneous low attenuation in the head of pancreas and distal common bile duct was compressed by the mass. During review of past medical records, we found that the mass was observed and measured about 1.7 cm seven years ago. To resolve obstructive jaundice, pylorus preserving pancreaticoduodenectomy was performed and diagnosed with well differentiated pancreatic neuroendocrine carcinoma with intermediate grade.

• Korean Chemical Engineering Research
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• 제62권3호
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• pp.201-213
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• 2024

세포는 40억년전에 처음 탄생하였으며, 오랜 기간동안 진화하며 발전해온 우수한 시스템이다. 상향식 합성생물학(bottom-up synthetic biology)은 40억년전으로 돌아가 세포를 기초부터 다시 설계하는 접근법으로 "인공세포(artificial cell)"를 개발하는 연구분야이다. 이렇게 개발된 인공세포는 비록 완벽한 세포는 아니지만 세포의 중요한 특징들을 보유한 인공적인 세포 유사(cell mimicry) 시스템이다. 인공세포를 설계함으로써 이 분야의 연구자들은 기존의 세포생물학과는 다른 접근법으로 세포의 체계와 근원을 탐구하고, 나아가서 살아있는 세포의 이용을 대체하고자 하는 목표를 가진다. 본 총설에서는 최근 활발히 연구되고 있는 캡슐 및 생물촉매 기반의 인공세포에 대한 개념 및 이 분야의 최신 연구들을 소개하고자 한다.

• 대한화학회지
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• 제58권3호
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• pp.277-282
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• 2014

2013년 국내에서 시판된 7개의 이부프로펜과 11개의 덱시부프로펜의 광학순도를 키랄 HPLC로 조사하였다. Chiralcel OD-H 칼럼과 LUX-Cellulose-1 칼럼을 키랄 정지상으로 사용하였고, hexane:isopropanol:acetic acid가 100:1:0.1로 혼합된 용액을 전개용매로 사용하여 흐름속도 1.0 mL/min에서 분석하였다. 각 시료를 최소 3회 이상 분석하여 얻은 평균값을 각각 계산하여 데이터로 이용하였고, 이들의 상대표준편차 평균값도 0.19%로 아주 작게 나타나 실험의 정밀도가 높음을 확인하였다. 실험에 사용된 11개 덱시부프로펜의 광학순도 평균값은 처음 판매가 허가된 2004년의 평균값인 99.2%에 비해 낮아졌지만 2010년의 평균값인 95.6% 보다는 높은 97.5%를 보였다. 그리고 실험에 이용된 모든 이부프로펜 두 거울상 이성질체의 조성비는 2010년 조사값(44:56)과는 달리 거의 50:50으로 얻어졌다.

• Advances in pediatric surgery
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• 제13권1호
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• pp.45-51
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• 2007

Appendicitis is the most common surgical emergency in childhood and the technologic advances of modern medicine have affected the diagnosis and treatment of appendicitis. This study is to evaluate the differences in diagnosis and treatment of appendicitis between present and 10 year ago. The authors retrospectively reviewed the medical records of patients who underwent appendectomy under the diagnosis of the acute appendicitis from July 1993 to June 1995 (Group A, n = 78) and from July 2003 to June 2005 (Group B, n = 105). There are no differences between group A and B in mean age ($8.5{\pm}3.6$ vs. $9.3{\pm}3.1$ year), duration of symptoms ($3.0{\pm}3.2$ vs. $2.6{\pm}3.8$ days), and postoperative hospital stay ($6.6{\pm}4.8$ vs. $5.8{\pm}3.6$ days). Preoperative abdominal ultrasonogram and/or computed tomogram was performed in 7 patients (9.0 %) of group A and in 51 patients (58.5 %) of group B. Thirty-six patients (34.3 %) of group B underwent laparoscopic appendectomy, but none in group A. Incidence of a histologically normal appendix decreased from 15.8 % in group A to 4.8 % in group B (p =0.018). This study suggests that utilization of abdominal ultrasonogram or computed tomogram in preoperative evaluation become more popular and surgical treatment of acute appendicitis become more minimally invasive. The rate of negative appendectomy was also reduced compared with 10 year ago.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.20-20
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.97-97
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Clinical and Experimental Pediatrics
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• 제50권10호
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• pp.954-958
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• 2007

목 적 : 본원에서 출생한 미숙아들을 대상으로 하여 이들 미숙아들 중에서 부당 경량아 출생과 관련이 있는 요인들에 대해 알아보고자 본 연구를 시행하였다. 방 법 : 2000년 1월부터 2006년 8월까지 출생한 재태 연령 26주 이상 35주 이하의 미숙아 1,010명을 대상으로 하였으며 이들과 이들의 모체의 의무기록을 후향적으로 조사하여 재태 연령, 출생 체중, 성별, 출생 순위, 산모의 나이 및 이전 유산 횟수 등에 관한 자료들을 수집하였고 부당 경량아 출생과 관련이 있는 요인들을 비교 분석하였다. 결 과 : 본 연구에서 미숙아들 중에서 여아에서 남아보다 부당 경량아 출생이 더 많은 것으로 나타났으며(P=0.042) 또한 산모의 나이가 20세 미만이거나 35세 이상인 경우에 부당 경량아 출생이 더 많은 것으로 나타났다(P=0.041). 미숙아의 출생 순위나 산모의 이전 유산 경력은 부당 경량아 출생과 통계학적인 관련성이 없는 것으로 나타났다(P=0.228, P=0.129). 결 론 : 출생 체중과 미숙아의 생존율과의 관련성을 생각해 보면 산모의 나이가 미숙아의 생존율과 관련이 있는 것으로 생각된다. 10대 임신을 줄이고 산모가 고령이 되기 전에 출산을 할 수 있도록 여러 사회적, 정책적인 뒷받침이 이루어진다면 미숙아들의 생존율을 높이고 더 나아가 건강한 정상 신생아 분만에도 큰 도움이 되리라 생각된다.

• 자원환경지질
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• 제47권1호
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• pp.17-27
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• 2014

ESR 연대를 이용하여, 울산광역시 울주군 삼남면 일대에 발달하는 양산단층대의 시간-공간적 활동 형태에 대해 연구하였다. 연구지역에서 일부 단층비지대는 기 형성된 단층비지 옆에 새로운 단층비지가 단층활동 형태 I에 의해 첨가되어 있다. 이럴 경우 각각의 단층비지에서 얻은 ESR 연대로부터 여러 번의 단층활동 시기를 해석하였다. 단층비 지대에서 일부분은 단층활동 형태 III에 의해 단층비지대 전체가 재 활동 하였다. 이와 같은 단층비지대는 이전의 활동 정보는 모두 지워지고 마지막 활동 시기만 기록되어 있다. 연구지역에서 양산단층대의 제4기 단층운동은 주기성을 가지며 활동기와 휴식기로 구분된다. ESR 연대 및 트렌치 조사 자료에 의하면, 연구지역에서 양산단층대의 단층활동은 이동하는 경향을 나타낸다. 약 75~85만 년 전을 기준으로 이전에는 서쪽분절로부터 북쪽분절까지, 약 75~85만년 전에는 동쪽분절로부터 북쪽분절까지 활동하였으며, 약 63~66만 년 전 및 48~54만 년 전에는 북쪽분절만 활동하였으며, 약 34만 년 전 이후에는 서쪽분절로부터 북쪽분절까지 다시 활동하였다.

• 한국직업건강간호학회지
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• 제4권호
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• pp.84-101
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• 1995

The periodic health examination have been shown the important role on early detection, early treatment and prevention of disease. Until now, there have been many studies that showed the effectiveness of the periodic health examination on the early detection and early treatment of disease to some extent. But there are few studies about primary prevention before health problem arise. In this case-control study, 29 newly detected hypertensive cases, 31 liver disease cases and 65 controls which are all available for 6-year data in the periodic health examination of a occupational field were compared to investigate the significant increase trend of health status between the groups. The results will be used for the occupational health nurses to provide appropriate primary prevention to the employees. The hypertensive and liver disease cases were divided observation-needed group and treatment-needed group. The data on systolic blood pressure, diastolic blood pressure, Body Mass Index and Broca Index in hypertensive cases and SGOT, SGPT, Body Mass Index and Broca Index in liver disease cases were analyzed by t-test and ANOVA. The specific findings are summarized as follows. 1. In the comparison between the hypertensive cases and controls, SBP and DBP of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2-3 years ago showing increase over 140/90mmHg of blood pressure in the hypertensive cases before they are categorized as hypertensive cases. In the observation-needed group and the treatment-needed group, the trend of the blood pressure for 6 years were significantly higher than the one of the controls. 2. In the comparison between the liver disease cases and controls, SGOT and SGPT of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2 years ago showing increase within upper normal limit of SGOT and 5 years ago of SGPT in the liver disease cases before they are categorized as liver disease cases. In the observation-needed group and the treatment-needed group, the trend of the liver enzyme for 6 years were significantly higher than the one of the controls. With these results, the author proposed that intervention for the primary prevention such as continuous follow-up, health education and weight control to the population who has over 140/90mmHg of blood pressure and upper normal limit of AST and ALT.

• 한국구조물진단유지관리공학회 논문집
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• 제15권6호
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• pp.118-126
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• 2011

본 연구의 목적은 전단경간비에 따른 합성지하벽의 거동을 실험적으로 연구하고 유한요소해석 프로그램인 ADINA를 활용하여 합성지하벽 (Composite Basement Wall, CBW)의 비선형 거동의 예측이다. 특히 각 층 바닥 부근과 같이 콘크리트가 압축응력상태일 때의 합성벽의 거동을 연구하였다. 특히 강재와 콘크리트가 접촉되는 부분의 모델링 방법에 따른 해석방법의 적합성을 검토하고자 하였다. 콘크리트 벽체부분이 압축응력상태에 있는 합성지하벽의 거동을 이해하기 위하여 합성지하벽에 대한 실험을 실시하고 ADINA 프로그램을 이용하여 유한요소해석을 실시하였다. 해석의 편의를 위하여, 철근은 별도의 독립 요소로 모델링하지 않고, 콘크리트에 등분포되어 콘크리트와 함께 거동하는 것으로 하고 모든 요소는 소성거동을 표현하기 위하여 이선형 모델로 하였다. 강재와 콘크리트의 접촉면과 관련해서는 접촉면의 연결조건에 따라, AGO, SEGO-T 그리고 SEGO-NT로 모델링하여 해석을 실시한 뒤 각 조건에 따른 응력흐름과 집중정도를 관찰하고 그 결과를 실험결과와 비교하였다. 연구결과, 합성지하벽은 전단경간비가 비록 1에 가깝더라도, 강재의 소성변형에 의해 충분히 연성적인 거동을 보이는 것으로 나타났으며, 이와 같은 거동을 묘사하기 위하여 ADINA 프로그램을 이용하여 콘크리트와 강재 및 스터드볼트의 비선형특성을 고려하고 접촉면 요소로서 강재와 콘크리트의 접합면을 모델링하여 해석한 결과 접촉면연결과 모든 절점공유 옵션을 사용한 모델을 적용할 경우, 실험결과와 근사한 예측이 가능한 것으로 나타났다.