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.

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

Cytotoxic Isoquinoline Alkaloids from the Aerial Parts of Corydalis incisa

Choi, Sang-Un,Baek, Nam-In,Kim, Sung-Hoon,Yang, Jae-Heon,Eun, Jae-Soon,Shin, Tae-Yong,Lim, Jong-Pil,Lee, Jae-Hyeok,Jeon, Hoon,Yun, Mi-Young,Leem, Kang-Hyun,Park, Hee-Wook,Kim, Dae-Keun 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.2

Three known isoquinoline alkaloids were isolated from the chloroform-soluble fraction of the methanolic extract of the aerial parts of Corydalis incisa (Papaveraceae) through repeated column chromatography. Their chemical structures were elucidated as corynoline (1), corynoloxine (2) and 6-oxocorynoline (3) using spectroscopic analysis. Compounds 1-3 exhibited cytotoxicity against human A549, SK-OV-3, SK-MEL-2 and HCT 15 tumor cells.

Two Years of Experience and Methodology of Korean COVID-19 Living Clinical Practice Guideline Development

Choi Miyoung,Lee Hyeon-Jeong,Yu Su-Yeon,Kim Jimin,Park Jungeun,Ryoo Seungeun,Kim Inho,Park Dong Ah,Yoon Young Kyung,Joh Joon-Sung,Park Sunghoon,Yun Ki Wook,Choi Chi-Hoon,Kim Jae-Seok,Shin Sue,Kim Hyun 대한의학회 2023 Journal of Korean medical science Vol.38 No.23

Background: In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration. Methods: The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations. Results: An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3–4 months. Conclusion: We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media. Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics.

Aloe-derived nanovesicles attenuates acute colonic inflammation in mice and enhances tight junction proteins in intestinal epithelial cells

Sang-Hun Choi,Hyun-Jin Kim,Yejin Sim,Dong-Ha Kim,Ji-Su Kim,Jaehee Kwon,Sang-Hoon Lee,Young-Eun Cho 한국식품영양과학회 2022 한국식품영양과학회 학술대회발표집 Vol.2022 No.10

Risk Factors for the Occurrence and Severity of Vertebral Fractures in Inflammatory Bowel Disease Patients: A Nationwide Population-Based Cohort Study

Choi Arum,Jung Sung Hoon,Kim Sukil,Lee Jun-Seok 대한의학회 2023 Journal of Korean medical science Vol.38 No.28

Background: The risk of vertebral fractures is increased in inflammatory bowel disease (IBD) patients. However, whether the severity of vertebral fractures differs between IBD patients and the general population, or between patients with Crohn’s disease (CD) and ulcerative colitis (UC), is unknown. Methods: We investigated risk factors associated with the occurrence and severity of vertebral fractures in IBD patients using The National Healthcare Insurance Service (NHIS) database. We defined the patients who underwent vertebroplasty or kyphoplasty after being diagnosed with a vertebral fracture as having a severe vertebral fracture than those with only diagnosis codes. Results: From 2008 to 2018, there were 33,778 patients with IBD (24,370 UC patients and 9,408 CD patients) and 101,265 patients in the reference population. The incidence rate ratio of vertebral fractures in the IBD patients was 1.27 per 1,000 person-years (95% confidence interval [CI], 1.26–1.27). The risk of vertebral fracture was higher in CD and UC patients than in the matched reference group (hazard ratio [HR], 1.59; 95% CI, 1.31–1.92; P < 0.001 and HR, 1.26; 95% CI, 1.14–1.41; P < 0.001, respectively). In a multivariate analysis, the occurrence of vertebral fracture was associated with CD (HR, 1.31; 95% CI, 1.08–1.59; P = 0.006), older age (CD: HR, 1.09; 95% CI, 1.08–1.09; P < 0.001 and UC: HR, 1.09; 95% CI, 1.08–1.09; P < 0.001), female sex (CD: HR, 1.81; 95% CI, 1.63–2.01; P < 0.001 and UC: HR, 2.02; 95% CI, 1.83–2.22; P < 0.001), high Charlson Comorbidity Index (CCI) score (CD: HR, 1.42; 95% CI, 1.23–1.63; P < 0.001 and UC: HR, 1.46; 95% CI, 1.29–1.65, P < 0.001), and long-term steroid use (CD: HR, 3.71; 95% CI, 2.84–3.37; P < 0.001 and UC: HR, 3.88; 95% CI, 3.07–4.91; P < 0.001). The severity of vertebral fractures was associated with IBD (CD: HR, 1.82; 95% CI, 1.17–2.83; P = 0.008 and UC: HR, 1.49; 95% CI, 1.17–1.89; P < 0.001) and older age (HR, 1.06; 95% CI, 1.05–1.07; P < 0.001). Conclusion: Vertebral fractures occur frequently and more severely in IBD patients, particularly those with CD. Therefore, we suggest monitoring of bone density, regular vitamin D supply, and reducing the use of corticosteroids to prevent vertebral fractures in IBD patients who are older, female, or have comorbidities.

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.

Changes in Clinical Characteristics and Outcome of Patients with Hepatocellular Carcinoma (HCC) in a 16-Year Cohort

( Sang Il Choi ),( Joong-won Park ),( Bo Hyun Kim ),( Ju Hee Lee ),( Seung Duk Lee ),( In Joon Lee ),( Tae Hyun Kim ),( Seong Hoon Kim ),( Young Hwan Koh ),( Hyun Beom Kim ),( Eun Kyung Hong ),( Chang 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: In South Korea, an endemic area of hepatitis B virus (HBV), the incidence and mortality of HCC is gradually decreasing by HBV vaccination, antiviral treatment, early tumor detection, improved treatment options, and evidence-based guidelines. This study investigated the changes over time in the baseline characteristics and clinical outcomes of HCC patients at a single center. Methods: Patients initially diagnosed with and treated for HCC at the National Cancer Center between 2000 and 2015 (n=4291) were followed-up until February 2017. Difference in patient characteristics and outcomes were compared in patients diagnosed in 2000-2004 (n=1157), 2005-2009 (n=1678), and 2010-2015 (n=1456). Results: The median age of the patient cohort was 57 years (range 13-98) years, and most were male (3502, 81.6%). HBV infection was the most common etiology (74.7%). The percentage of patients with Child class A (69.1%, 79.9%, and 87.1%, respectively) and BCLC stage 0 (4.1%, 5.2%, and 9.8%, respectively) increased significantly over time. Median overall survival also increased significantly over time, from 14.4 months (95% confidence interval [CI] 12.0-16.8 months) in 2000-2004, to 22.9 months (95% CI, 20.3-25.5 months) in 2005-2009, to 53.6 months (95% CI, 45.7- 61.5 months) in 2010-2015 (p<0.001). OS of patients with modified UICC stage IV (3.6 vs. 4.7 vs 6.1 months, p<0.001) and with HBV etiology (12.7 vs 20.4 vs 64.5 months, p<0.001) was observed in patients diagnosed in 2000-2004, 2005-2009 and 2010-2015, respectively. Conclusions: Survival of patients with HCC has improved significantly over time in a single center in South Korea. Analysis is ongoing to determine the causes of the improved outcomes.