Solar Cells: Amorphous Zinc Stannate (Zn₂SnO₄) Nanofibers Networks as Photoelectrodes for Organic Dye‐Sensitized Solar Cells (Adv. Funct. Mater. 25/2013)

Choi, Seung‐,Hoon,Hwang, Daesub,Kim, Dong‐,Young,Kervella, Yann,Maldivi, Pascale,Jang, Sung‐,Yeon,Demadrille, Renaud,Kim, Il‐,Doo WILEY‐VCH Verlag 2013 Advanced Functional Materials Vol.23 No.25

<P>Highly porous amorphous Zn<SUB>2</SUB>SnO<SUB>4</SUB> electrodes are prepared using electrospinning techniques and combined with organic or ruthenium dyes to fabricate dye‐sensitized solar cells. As reported by Sung‐Yeon Jang, Renaud Demadrille, Il‐Doo Kim, and co‐workers on page 3146, the devices based on 3‐μm‐thick electrodes and the organic dyes demonstrate significantly improved performances compared to those using the ruthenium complex. Using this approach, solar cells with power conversion efficiencies up to 3.7% are obtained. </P>

압축성 코드에서 예조건화 코드로의 이진

한상훈(Sang-Hoon Han),김명호(Myeong-Ho Kim),최정열(Jeong-Yeol Choi) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.3

이차원 범프 유동에 대한 다양한 예조건화 행렬의 수렴 특성을 살펴 Choi와 Merkle의 예조건화 행렬을 선택하여, 압축성 및 예조건화 Roe의 Riemann 해법의 수치 소산항을 수학적으로 비교하였다. 이 결과 코드의 구조는 동일하게 유지한 채, 고유치의 작은 수정만으로 압축성 해법을 예조건화 해법으로 이전할 수 있는 방법을 알 수 있었다. 아울러 점성 유동 영역에서의 안정성 및 정확성을 향상시키기 위하여 von Neumann 안정 조건 및 점성 자코비안을 고려하였으며, 개발된 코드는 표준 검증 문제에 적용하여 검증을 수행하였다. Comprehensive mathematical comparison of numerical dissipation vector was made for a compressible and the preconditioned version Roe's Riemann solvers. Choi and Merkle type preconditioning method was selected from the investigation of the convergence characteristics of the various preconditioning methods for the flows over a two-dimensional bump. The investigation suggests a way of migration from a compressible code to a preconditioning code with a minor changes in Eigenvalues while maintaining the same code structure. Von Neumann stability condition and viscous Jacobian were considered additionally to improve the stability and accuracy for the viscous flow analysis. The developed code was validated through the applications to the standard validation problems.

최씨 훅을 이용한 복강경 버찌씨 수술

김영혜 ( Young Hye Kim ),박준선 ( Jun Seon Park ),최상준 ( Sang Joon Choi ),송창훈 ( Chang Hoon Song ),한세준 ( Sei Jun Han ),정혁 ( Hyuk Jung ) 대한산부인과학회 2006 Obstetrics & Gynecology Science Vol.49 No.6

목적: 버찌씨 수술은 복압성 요실금 수술에 효과적인 수술로 여겨져 왔다. 요실금의 원인이 내인성 요도 괄약근의 결손소견 없이 요도의 과운동성으로 인한 경우 버찌씨 수술이 일반적으로 추천되어진다. 본 연구에서는 복강경 버찌씨 수술에서 최씨 훅의 유용성에 대해 알아보고자 하였다. 연구방법: 2000년 10월부터 2005년 3월까지 본원에서 복강경 버찌씨 수술을 시행받은 47명의 환자를 대상으로 하였다. 27명은 고전적 복강경 버찌씨 수술을 시행하였고 20명은 내골반 근막을 Cooper 인대를 부착하는데 유용한 본원에서 고안한 최씨 훅을 이용하여 복강경 버찌씨 수술을 시행하였다. 결과: 고전적 복강경 버찌씨 수술을 시행한 군과 최씨 훅을 이용한 복강경 버찌씨 수술을 시행한 군의 평균 나이, 분만력, 폐경률, BMI는 두 군간에 통계학적으로 유의한 차이를 보이지 않았다 (p>0.05). 수술 시간은 고전적 복강경 버찌씨 수술은 90.52±15.32분, 최씨 훅을 이용한 복강경 버찌씨 수술은 38.50±10.14분으로 최씨 훅을 이용한 경우 수술시간이 통계적으로 유의하게 짧았다 (p<0.05). 두 군간에 재발률 및 합병증 발생은 통계적 유의성을 보이지 않았다 (p>0.05). 결론: 본 연구에서 본원에서 고안한 최씨 훅을 이용하여 복강경 버찌씨 수술을 시행한 결과 수술 시간을 단축시킬 수 있었으며 수술 효과는 기존 방법과 동일하게 관찰되었다. 이에 최씨 훅은 복강경 버찌씨 수술에서 사용할 때 집도자의 봉합 과정을 단순화시켜 수술 시간을 단축시키므로 복강경 버찌씨 수술에 용이한 기구이다. Objective: Burch operation has been effective method for the treatment of stress incontinence. Burch operation is a well-accepted procedure for treating stress urinary incontinence secondary to urethral hypermobility without intrinsic sphincter deficiency and is the reference standard with which other procedures are compared. This study is to evaluate the effectiveness of the Choi`s hook in laparoscopic Burch operation. Methods: This study included 47 patients who had undergone laparoscopic Burch operation from October 2000 through March 2005. Of these 47 patients, 27 patients underwent traditional laparoscopic Burch operation (Group 1) and 20 patients underwent laparoscopic Burch operation with Choi`s Hook on anchoring the endopelvic fascia to the Cooper`s ligament (Group 2). Results: The mean age of patients of Group 1 was 55.6±9.37 years of age and that of Group 2 was 56.0±5.93 years of age. There is no difference in the mean age of patients (P>0.05). The mean operating time was 90.5±15.32 minutes for Group 1 and 38.5±10.14 minute for Group 2. The mean operating time was shorter in Group 2 than Group 1 (P<0.05). There was no difference in recurrence rate and complication rate between Group 1 and Group 2 (P>0.05). Conclusion: We performed laparoscopic Burch operation with the Choi`s Hook on anchoring the endopelvic fascia to the Cooper`s ligament. When we compared traditional laparoscopic Burch operation with laparoscopic Burch operation with Choi`s Hook, we could shorten the operation time using the Choi`s Hook.

High-Temperature Stable Operation of Nanoribbon Field-Effect Transistors

Choi, Chang-Young,Lee, Ji-Hoon,Koh, Jung-Hyuk,Ha, Jae-Geun,Koo, Sang-Mo,Kim, Sangsig Springer 2010 NANOSCALE RESEARCH LETTERS Vol.5 No.11

<P>We experimentally demonstrated that nanoribbon field-effect transistors can be used for stable high-temperature applications. The on-current level of the nanoribbon FETs decreases at elevated temperatures due to the degradation of the electron mobility. We propose two methods of compensating for the variation of the current level with the temperature in the range of 25–150°C, involving the application of a suitable (1) positive or (2) negative substrate bias. These two methods were compared by two-dimensional numerical simulations. Although both approaches show constant on-state current saturation characteristics over the proposed temperature range, the latter shows an improvement in the off-state control of up to five orders of magnitude (−5.2 × 10<SUP>−6</SUP>).</P>

Modification of the TNM Staging System for Stage II/III Gastric Cancer Based on a Prognostic Single Patient Classifier Algorithm

Choi, Yoon Young,Jang, Eunji,Seo, Won Jun,Son, Taeil,Kim, Hyoung-Il,Kim, Hyeseon,Hyung, Woo Jin,Huh, Yong-Min,Noh, Sung Hoon,Cheong, Jae-Ho The Korean Gastric Cancer Association 2018 Journal of gastric cancer Vol.18 No.2

Purpose: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. Materials and Methods: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. Results: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41-2.72; P<0.001) and 2.54 (95% CI, 1.84-3.50; P<0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P<0.001). Conclusions: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.

Usefulness of Epigenetic Biomarkers in Plasma for Detection of Colorectal Cancer

( Hoon Kang ),( Soong Lee ),( Ki Sang Lee ),( Seung Chul Pack ),( Hyeon Min Lee ),( Jae Kyu Lim ),( David Hwang ),( Seong Il Park ),( Sung Kyu Choi ) 대한내과학회 2011 대한내과학회 추계학술대회 Vol.2011 No.1

Background and Aims: Colorectal cancer (CRC) developed from accumulation of genetic and epigenetic alterations in colonic epithelial cells. The aim of the study was evaluated promoter methylation in 5 genes, which are known to be involved in the pathogenesis of colorectal cancer and are frequently silenced by hypermethylation in colorectal cancer. Methods: Five markers were selected for analysis in plasma samples from 30 CRC and 50 non-CRC patients. The methylation states of promoter regions of the SMAD4, FHIT, DAPK1, APC and E-cadherin gene were examined. The methylation status of the 5 genes was determined using polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP). Results: This study showed the most sensitive marker was E-cadherin, which amplified 90% of CRC patients, followed by APC (85%) and SMAD4 (71%). E-cadherin and APC had similar specificities and amplified 84% and 86% of CRC patients compared to non-CRC patients, respectively. Then we observed sensitivity and specificity to compare the methylation states of stages I CRC patients and normal control. The result indicated the most sensitive marker was APC, 50% of CRC patients, followed by E-cadherin (38%) and SMAD4 (31%). The most specific marker was APC, 89% of CRC patients, followed by E-cadherin (87%) and SMAD4 (87%). Conclusions: Among the five genes tested, E-cadherin methylation seems to have the highest probability of detection of CRC patients compared to non-CRC patients in blood. For detection stage I CRC compared to normal control, the most sensitive and specific marker was APC. Our exploratory study indicates that APC may be able to identify potentially early CRC. In this study, E-cadherin and APC were useful epigenetic biomarkers in blood for detection of CRC.

Subdural Empyema Treated by Continuous Irrigation and Drainage Catheter Insertion in a Young Adult Patient with Hemiparesis: A Case Report

Sang Hoon Baek,Seok Keun Choi,Jiwook Ryu,Lee Sung Ho 대한말초신경학회 2017 The Nerve Vol.3 No.2

Spontaneous subdural empyema is a rare disease in developed society, especially in adults. A 30-year-old male visited our clinic with alteration of consciousness as the main symptom. On initial computed tomography (CT), subdural hematoma was suspected but after performing craniectomy, the lesion was identified as a subdural empyema. Thus, we inserted and maintained a continuous irrigation and drainage catheter for the short term using broad spectrum antibiotics. The patient underwent another operation to remove the remnant empyema and 3 months of rehabilitation following the second operation, after which he went on to lead a normal life without neurologic deficit.

The efficacy of intralesional MMR vaccine for the treatment of warts in adult

( Sang Hyun Song ),( Sang Ho Youn ),( Hoon Choi ),( Chan Ho Na ),( Min Sung Kim ),( Bong Seok Shin ),( Kyu Chul Choi ) 대한피부과학회 2012 대한피부과학회 학술발표대회집 Vol.64 No.3

Phosphorylated Intermediate of Hepatic Glucose-6-Phosphatase

Choi, Young-Hoon,Choi, Hong-Suk,Oh, Jung-A,Park, Jong-Sang 생화학분자생물학회 1993 한국생화학회지 Vol.26 No.4

Glucose-6-phosphatase is an important enzyme involved in the regulation of concentration of glucose in blood. Steady-state labeling, a method to incorporate $^{32}P$ to the active site of Glucose-6-Phosphatase, was employed to identify the target enzyme. By the steady state labeling about 62-kDa protein was labeled in the microsome from rat liver. The 62-kDa band disappeared in the presence of known inhibitors and competitors of glucose-6-phosphatase. 35-kDa protein was digested protein fragment from the 62-kDa protein. These results showed that the 62-kDa protein was the phosphohydrolase component of glucose-6-phosphatase system.

[Poster] Is it worth while to preserve adult spleen in laparoscopic distal pancreatectomy?

Sung Hoon Choi,Mi Ae Seo,Ho Kyoung Hwang,Chang Moo Kang,Woo Jung Lee 대한외과학회 2011 대한외과학회 학술대회 초록집 Vol.2011 No.11