이중구조 촉매전극을 이용한 알칼리 연료전지에 관한 연구

노용우,이태희,설용건,장의종,김경림 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.1

An experimental low-temperature low-pressure hydrogen-oxygen alkali fuel cell was constructed and its performance was tested for various operating conditions. Hydrogen was used for fuel and oxygen was used for oxidant and KOH solution was used for electrolyte. Both electrodes for hydrogen and oxygen were prepared by the same method and the materials used were carbonyl nickel and ammonium bicarbonate. Experimental results show that maximum current density of 8.91 mA/㎠ was obtained at 40℃ wt% KOH solution and optimum power was 1.74 mW/㎠ at 6.43 mA/㎠ current density.

Decoration of 1,3,5-triazine backbone structure with dibenzofuran and triphenylsilyl blocking groups for high stability n-type host in deep blue phosphorescent organic light-emitting diodes

Eui Gun Lee,양창윤,정원재,이준엽 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.95 No.-

The development of the triazine derivatives as the n-type (electron transport type) host for long devicelifetime in deep blue phosphorescent organic light-emitting diodes (PhOLEDs) was studied bysynthesizing two hosts with dibenzofuran and triphenylsily blocking groups. The triazine core waslocated at the center of the molecule and the triphenylsilyl group behaved as the blocking group of theplanar core. The dibenzofuran was also attached to the triazine core for electron transport and high tripletenergy. Two hosts with different number of dibenzofuran and tripheynylsilyl units were synthesized andthe number of triphenylsilyl group was critical to the device lifetime results. The two hosts showed highexternal quantum efficiency over 20%, but the device lifetime was doubled by introducing twotriphenylsilyl units instead of one triphenylsilyl group. A device lifetime of 2200 h at 100 cd/m2 wasachieved using the new host. It was revealed that enlarging the intermolecular distance by inserting twobulky groups in the hosts had positive effects on increasing the device lifetime.

Topoisomerase Ⅱ-mediated DNA Cleavage on the Cruciform Structurre formed within the 5' Upstream Region of the Human β-Globin Gene

Lee, Gun Eui,Kim, Jun Hyun,Chung, In Kwon Korean Society of Molecular Biology 1998 Molecules and cells Vol.8 No.4

Common and rare variants in the exons and regulatory regions of osteoporosis-related genes improve osteoporotic fracture risk prediction.

Lee, Seung Hun,Kang, Moo Il,Ahn, Seong Hee,Lim, Kyeong-Hye,Lee, Gun Eui,Shin, Eun-Soon,Lee, Jong-Eun,Kim, Beom-Jun,Cho, Eun-Hee,Kim, Sang-Wook,Kim, Tae-Ho,Kim, Hyun-Ju,Yoon, Kun-Ho,Lee, Won Chul,Kim, Issued for the Endocrine Society by the Williams W 2014 The Journal of clinical endocrinology & metabolism Vol.99 No.11

<P>Osteoporotic fracture risk is highly heritable, but genome-wide association studies have explained only a small proportion of the heritability to date. Genetic data may improve prediction of fracture risk in osteopenic subjects and assist early intervention and management.</P>

매체와 정보유형에 따른 정보확산 차이에 대한 연구

이상근(Sang-Gun Lee),김진화(Jin-Hwa Kim),백헌(Heon Baek),이의방(Eui-Bang Lee) 한국지능정보시스템학회 2013 지능정보연구 Vol.19 No.4

본 연구는 매체에 따른 정보확산차이와, 정보유형을 근접성의 정도로 분류하여 정보확산차이를 보고자 하였다. 이는 기존의 전통매체인 종이신문이나 TV, 라디오와 같이 일방적으로 전달되는 매체의 정보확산과는 달리, 온라인 뉴스나 소셜네트워크서비스와 같이 쌍방향적 소통이 가능한 매체 특성으로 인한 정보확산은 차이가 있을 것이라 판단하였다. 따라서 본 연구에서는 개인이 직접 기사를 올리고 다른 사람들과 공유할 수 있는 블로그(Blog) 매체와 온라인 뉴스(News) 매체에 따른 정보확산차이를 비교해 보고자 하였다. 또한 심리적, 지리적 근접성에 따른 정보확산차이를 보고자 정보의 유형을 세분화 하였다. 이는 수용자가 정보의 근접성이 높고 낮음의 차이 정도에 따라 정보유형에 따른 가치평가의 기준이 다를 것이라 보았다. 정보유형은 연예, 시사(국제), 제품으로 선정하였고, 세부내용은 연예와 관련된 ‘싸이 젠틀맨’, 시사와 관련된 ‘중국 쓰촨성 지진’, 제품과 관련된 ‘갤럭시 S4’를 선택하였다. 본 연구의 분석방법은 Bass 확산모형을 이용하여 증명하고자 하였다. Bass 확산모형은 혁신효과(Innovation effect)와 모방효과(Imitation effect)로 나눠서 측정한다. 혁신효과는 서비스 초기에 영향을 미치는 변수로 추정가능하며, 모방효과는 서비스 초기 단계 이후에 영향을 미치는 변수로 구전의 영향을 받는다고 볼 수 있다. 본 연구 결과 첫째, 매체에 따른 정보확산 흐름은 비슷하게 나타났다. 비록 두 매체의 특성에 차이점이 있을지라도, 뉴스가치 중 하나인 근접성에 따른 정보확산은 비슷한 형태를 보인다고 할 수 있다. 두 번째, 근접성에 기반한 정보유형별 정보확산에는 차이가 있었다. 수용자 입장에서 관련성이 높은 제품과 연예는 모방효과가 높게 나타났으며, 시사의 경우는 모방효과보다 혁신효과가 높게 나타났다. 이는 제품관련 정보나 연예관련 정보와 같이 개인에게 심리적으로나 지리적으로 근접성이 높은 정보는, 국제 재해와 관련된 시사정보와 같이 근접성이 낮은 정보에 비해서, 개인의 모방효과가 활발히 진행된다고 볼 수 있다. 연구결과를 통해 매체와 정보유형에 따라 정보확산 흐름변화를 고찰하여 실무에 활용한다면 도움이 될 것이라 본다. 하지만, 정보유형을 각각 하나의 기사만을 택하여 보았기 때문에 이 결과를 통한 정보확산 차이라고 규정짓기에는 sample size가 너무 작아 일반화에 어려움이 있다. 향후 연구에서는 소셜미디어 종류를 블로그 뿐 만 아니라 다양한 소셜미디어를 추가하여 비교해 볼 필요가 있을 것이다. 또한 정보의 유형을 근접성 측면뿐 만 아니라 다른 측면도 고려해 봐야 할 것이다.

Comparative Genomic Analysis of Staphylococcus aureus FORC_001 and S. aureus MRSA252 Reveals the Characteristics of Antibiotic Resistance and Virulence Factors for Human Infection

( Sooyeon Lim ),( Dong Hoon Lee ),( Woori Kwak ),( Hakdong Shin ),( Hye Jin Ku ),( Jong Eun Lee ),( Gun Eui Lee ),( Heebal Kim ),( Sang Ho Choi ),( Sangryeol Ryu ),( Ju Hoon Lee ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.1

Staphylococcus aureus is an important foodborne pathogen that causes diverse diseases ranging from minor infections to life-threatening conditions in humans and animals. To further understand its pathogenesis, the genome of the strain S. aureus FORC_001 was isolated from a contaminated food. Its genome consists of 2,886,017 bp double-stranded DNA with a GC content of 32.8%. It is predicted to contain 2,728 open reading frames, 57 tRNAs, and 6 rRNA operons, including 1 additional 5S rRNA gene. Comparative phylogenetic tree analysis of 40 complete S. aureus genome sequences using average nucleotide identity (ANI) revealed that strain FORC_001 belonged to Group I. The closest phylogenetic match was S. aureus MRSA252, according to a whole-genome ANI (99.87%), suggesting that they might share a common ancestor. Comparative genome analysis of FORC_001 and MRSA252 revealed two non-homologous regions: Regions I and II. The presence of various antibiotic resistance genes, including the SCCmec cluster in Region I of MRSA252, suggests that this strain might have acquired the SCCmec cluster to adapt to specific environments containing methicillin. Region II of both genomes contains prophage regions but their DNA sequence identity is very low, suggesting that the prophages might differ. This is the first report of the complete genome sequence of S. aureus isolated from a real foodborne outbreak in South Korea. This report would be helpful to extend our understanding about the genome, general characteristics, and virulence factors of S. aureus for further studies of pathogenesis, rapid detection, and epidemiological investigation in foodborne outbreak.

Optimization to detect TP53 mutations in circulating cell-free tumor DNA from patients with serous epithelial ovarian cancer

( Yu Ran Park ),( Yong-man Kim ),( Shin Wha Lee ),( Ha Young Lee ),( Gun Eui Lee ),( Jong-eun Lee ),( Young-tak Kim ) 대한산부인과학회 2018 Obstetrics & Gynecology Science Vol.61 No.3

Objective Circulating cell-free tumor DNA (cfDNA) is the DNA released by apoptotic and necrotic cells of the primary tumor into the blood during the period of tumor development. The cfDNA reflects the genetic and epigenetic alterations of the original tumor. TP53 mutations are a defining feature of high-grade serous ovarian carcinoma. We optimized the methods for detecting TP53 mutations in cfDNA from blood samples. We confirmed the correlation of TP53 mutation in primary ovarian cancer tissue and it in cfDNA using digital polymerase chain reaction (dPCR). Methods We found 12 frequent mutation sites in TP53 using The Cancer Genome Atlas and Catalogue of Somatic Mutations in Cancer data and manufactured 12 primers. The mutations in tissues were evaluated in fresh-frozen tissue (FFT) and formalin-fixed paraffin-embedded tissue (FFPET). We performed a prospective analysis of serial plasma samples collected from 4 patients before debulking surgery. We extracted cfDNA and calculated its concentration in blood. dPCR was used to analyze TP53 mutations in cfDNA, and we compared TP53 mutations in ovarian cancer tissue with those in cfDNA. Results Ten primers out of 12 detected the presence of TP53 mutations in FFT, FFPET, and cfDNA. In FFT and FFPET tissue, there were no significant differences. The average cfDNA concentration was 2.12±0.59 ng/mL. We also confirmed that mutations of cfDNA and those of FFT were all in R282W site. Conclusion This study developed detection methods for TP53 mutations in cfDNA in ovarian cancer patients using dPCR. The results demonstrated that there are the same TP53 mutations in both ovarian cancer tissue and cfDNA.

High-resolution Impedance Manometry Criteria in the Sitting Position Indicative of Incomplete Bolus Clearance

( Eui Ju Park ),( Joon Seong Lee ),( Tae Hee Lee ),( Gene Hyun Bok ),( Su Jin Hong ),( Hyun Gun Kim ),( Seong Ran Jeon ),( Jin Oh Kim ) 대한소화기기능성질환·운동학회 2014 Journal of Neurogastroenterology and Motility (JNM Vol.20 No.4

Background/Aims We used high-resolution impedance manometry (HRIM) to determine the length of breaks on the isobaric contour which would predict incomplete bolus clearance in patients in the sitting position. Methods In total, 651 swallows in 71 patients with esophageal symptoms were studied using a solid-state HRIM system in the sitting position. Each swallow was classified as complete or incomplete bolus clearance by impedance criteria and peristaltic integrity was evaluated using 20- and 30-mmHg pressure topography isobaric contours. Correlations between the lengths of the breaks for 20- and 30-mmHg were analyzed. Results Complete bolus clearance was observed in 83.3% (542/651) of swallows. Breaks of 3 and 7 cm or less were associated with a bolus clearance of 96.8% on the 20-mmHg and 94.7% on the 30-mmHg isobaric contour, respectively (P < 0.001). The areas under the ROC curves for the 20 and 30 mmHg isobaric contours were 0.900 and 0.950, respectively. The sensitivity and specificity for complete bolus clearance were 75.6% and 89.3% for breaks 3 cm or less on the 20-mmHg isobaric contour and 87.9% and 78.7% for breaks 7 cm or less on the 30-mmHg contour (P < 0.001). Conclusions Breaks of < 3 cm in the 20-mmHg isobaric contour or < 7 cm in the 30-mmHg isobaric contour were associated with com - plete bolus clearance. The threshold for breaks in the sitting position was greater than previous reports using the supine position and longer breaks predicted incomplete bolus clearance.

Terahertz band gaps induced by metal grooves inside parallel-plate waveguides.

Lee, Eui Su,So, Jin-Kyu,Park, Gun-Sik,Kim, Daisik,Kee, Chul-Sik,Jeon, Tae-In Optical Society of America 2012 Optics express Vol.20 No.6

<P>We report experimental and finite-difference time-domain simulation studies on terahertz (THz) characteristics of band gaps by using metal grooves which are located inside the flare parallel-plate waveguide. The vertically localized standing-wave cavity mode (SWCM) between the upper waveguide surface and groove bottom, and the horizontally localized SWCM between two groove side walls (groove cavity) are observed. The E field intensity of the horizontally localized SWCM in grooves is very strongly enchanced which is three order higher than that of the input THz. The 4 band gaps except the Bragg band gap are caused by the pi radian delay (out of phase) between the reflected THz field by grooves and the propagated THz field through the air gap. The measurement and simulation results agree well. (C) 2012 Optical Society of America</P>

Clinical significance of single-port laparoscopic splenectomy

Eui Soo Han,Young Kyoung You,Dong Goo Kim,Jun Suh Lee,Eun Young Kim,Soo Ho Lee,Tae Ho Hong,Gun Hyung Na 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.89 No.2

Purpose: Single-port laparoscopic splenectomy has been performed sporadically. The aim of this study is to assess our experience with single-port laparoscopic splenectomy compared to conventional multiport laparoscopic surgery for the usual treatment modality for various kinds of splenic disease. Methods: Between October 2008 to February 2014, 29 patients underwent single-port laparoscopic splenectomy and 32 patients received multiport laparoscopic splenectomy. We retrospectively analyzed the clinical outcomes of single-port group and multiport group. Results: The body mass index and disease profiles of the both groups were similar. The operative times of single-port and multiport group were 113.6 ± 39.9 and 95.9 ± 38.9 minutes, respectively (P = 0.946). The operative blood loss of the two groups were 295.8 ± 301.3 and 322.5 ± 254.5 mL (P = 0.582). Postoperative retrieved splenic weight of the single-port and multiport groups were 283.9 ± 300.7 and 362.3 ± 471.8 g, respectively (P = 0.261). One single-port partial splenectomy and 6 multiport partial splenectomies were performed in this study. There was one intraoperative gastric wall injury. It occurred in single-port group, which was successfully managed during the operation. Each case was converted to laparotomy in both groups due to bleeding. There was one mortality case in the multiport laparoscopic splenectomy group, which was not related to the splenectomy. Mean hospital stay of the single-port and multiport group was 5.8 ± 2.5 and 7.3 ± 5.2 days respectively (P = 0.140). Conclusion: Single-port laparoscopic splenectomy seems to be a feasible approach for various kinds of splenic disease compared to multiport laparoscopic surgery.