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.

Clinical Experiences of Transforaminal Balloon Decompression for Patients with Spinal Stenosis

( Sung Hoon Kim ),( Won Uk Koh ),( Soo Jin Park ),( Woo Jong Choi ),( Jeong Hun Suh ),( Jeong Gil Leem ),( Pyung Hwan Park ),( Jin Woo Shin ) 대한통증학회 2012 The Korean Journal of Pain Vol.25 No.1

Lumbar spinal stenosis is a commonly treated with epidural injections of local anesthetics and corticosteroids, however, these therapies may relieve Leg pain for weeks to months but do not influence functional status. Furthermore, the majority of patients report no substantial symptom change over the repeated treatment. Utilizing balloon catheters, we successfully treated with three patients who complained persistent symptoms despite repeated conventional steroid injections. Our results suggest that transforaminal decompression using a balloon catheter may have potential in the nonsurgical treatment of spinal stenosis by modifying the underlying pathophysiology. (Korean J Pain 2012; 25: 55-59)

Off-Target ¹⁸F-AV-1451 Binding in the Basal Ganglia Correlates with Age-Related Iron Accumulation

Choi, Jae Yong,Cho, Hanna,Ahn, Sung Jun,Lee, Jae Hoon,Ryu, Young Hoon,Lee, Myung Sik,Lyoo, Chul Hyoung Society of Nuclear Medicine 2018 The Journal of nuclear medicine Vol.59 No.1

<P>Off-target binding in the basal ganglia is commonly observed in the <SUP>18</SUP>F-AV-1451 PET studies of the elderly. We sought to investigate the relationship between this phenomenon in the basal ganglia and iron accumulation using iron-sensitive R<SUB>2</SUB>* MRI. <B>Methods:</B> Fifty-nine healthy controls and 61 patients with Alzheimer disease and mild cognitive impairment underwent <SUP>18</SUP>F-AV-1451 PET and R<SUB>2</SUB>* MRI studies. A correlation analysis was performed for age, <SUP>18</SUP>F-AV-1451 binding, and R<SUB>2</SUB>* values. <B>Results:</B> There was an age-related increase in both <SUP>18</SUP>F-AV-1451 binding in the basal ganglia and R<SUB>2</SUB>* values in the putamen in both the controls and the Alzheimer disease/mild cognitive impairment patients. <SUP>18</SUP>F-AV-1451 binding in the basal ganglia increased with R<SUB>2</SUB>* values. <B>Conclusion:</B> Off-target <SUP>18</SUP>F-AV-1451 binding in the basal ganglia is associated with the age-related increases in iron accumulation. Postmortem studies are required to further investigate the nature of this association.</P>

A novel voxel-wise lesion segmentation technique on 3.0-T diffusion MRI of hyperacute focal cerebral ischemia at 1 h after permanent MCAO in rats

Choi, Chi-Hoon,Yi, Kyung Sik,Lee, Sang-Rae,Lee, Youngjeon,Jeon, Chang-Yeop,Hwang, Jinwoo,Lee, Chulhyun,Choi, Sung Sik,Lee, Hong Jun,Cha, Sang-Hoon SAGE Publications 2018 Journal of cerebral blood flow and metabolism Vol.38 No.8

<P> To assess hyperacute focal cerebral ischemia in rats on 3.0-Tesla diffusion-weighted imaging (DWI), we developed a novel voxel-wise lesion segmentation technique that overcomes intra- and inter-subject variation in apparent diffusion coefficient (ADC) distribution. Our novel technique involves the following: (1) intensity normalization including determination of the optimal type of region of interest (ROI) and its intra- and inter-subject validation, (2) verification of focal cerebral ischemic lesions at 1 h with gross and high-magnification light microscopy of hematoxylin-eosin (H&E) pathology, (3) voxel-wise segmentation on ADC with various thresholds, and (4) calculation of dice indices (DIs) to compare focal cerebral ischemic lesions at 1 h defined by ADC and matching H&E pathology. The best coefficient of variation was the mode of the left hemisphere after normalization using whole left hemispheric ROI, which showed lower intra- (2.54 ± 0.72%) and inter-subject (2.67 ± 0.70%) values than the original. Focal ischemic lesion at 1 h after middle cerebral artery occlusion (MCAO) was confirmed on both gross and microscopic H&E pathology. The 83 relative threshold of normalized ADC showed the highest mean DI (DI = 0.820 ± 0.075). We could evaluate hyperacute ischemic lesions at 1 h more reliably on 3-Tesla DWI in rat brains. </P>

Postoperative radiotherapy for endometrial cancer

Choi, Eun Cheol,Kim, Jin Hee,Kim, Ok Bae,Byun, Sang Jun,Park, Seung Gyu,Kwon, Sang Hoon The Korean Society for Radiation Oncology 2012 Radiation Oncology Journal Vol.30 No.3

Purpose: To investigate the prognostic factors and effectiveness of postoperative radiotherapy alone for endometrial carcinoma. Materials and Methods: Sixty four patients with stage I-III endometrial cancer (EC) treated with postoperative radiotherapy alone between January 1989 and December 2008 at the Keimyung University Dongsan Medical Center were chosen for the present study. Typically, total hysterectomy, salpingo-oophorectomy and lymphadenectomy were performed on the patient's pelvis. Total dose from 50.4 Gy to 63 Gy was irradiated at pelvis or extended field. Thirteen patients were treated with Co-60 or Ir-192 intracavitary radiotherapy. Follow-up periods were from 7 to 270 months, with a median of 56 months. Results: Five year overall survival (OS) rate was 58.7%, respectively. Five year disease-free survival (DFS) rate was 59.2%, respectively. In univariate analysis for OS and DFS, stage, menopausal age, type of operation, serosal invasion, and lymph node involvement were found to be statistically significant. Histologic type was marginally significant. In multivariate analysis for OS and DFS, stage, types of operation, histologic type were also found to be statistically significant. Treatment failure occurred in 14 patients. The main pattern of failure was found to be distant metastasis. Time to distant metastasis was from 3 to 86 months (median, 12 months). There were no grade 3 or 4 complications. Conclusion: Stage, types of operation, and histologic type could be the predictive prognostic factors in patients. We contemplated postoperative radiation as effective and safe treatment method for EC. Additional treatment would be needed to reduce distant metastasis.

Impaired polyfunctionality of CD8 ⁺ T cells in severe sepsis patients with human cytomegalovirus reactivation

Choi, Young Joon,Kim, Sun Bean,Kim, Jong Hoon,Park, Su-Hyung,Park, Moo Suk,Kim, June Myung,Han, Sang Hoon,Shin, Eui-Cheol Nature Publishing Group 2017 Experimental and molecular medicine Vol.49 No.9

<P>Human cytomegalovirus (HCMV) establishes a lifelong chronic latent infection and often reactivates in immunocompromised patients. In addition, HCMV reactivates in patients with sepsis or other critical illnesses, particularly in patients with poor prognoses. However, the immunological characteristics of sepsis patients with HCMV reactivation have not been elucidated. In the present study, we examined T-cell responses in severe sepsis patients with and without HCMV reactivation. First, HCMV pp65-specific T-cell functions were assessed by intracellular cytokine staining (ICS) for IFN-γ, TNF-α, and MIP-1β and by CD107a staining. We analyzed the ICS data for each function individually and found no difference between the patient groups. However, the relative frequency of polyfunctional CD8<SUP>+</SUP> T cells was significantly decreased in sepsis patients with HCMV reactivation. Next, we examined programmed cell death protein 1 (PD-1) expression. It was significantly increased in the CD8<SUP>+</SUP> T-cell population in severe sepsis patients with HCMV reactivation, indicating CD8<SUP>+</SUP> T-cell exhaustion. Interestingly, the frequency of PD-1<SUP>+</SUP> cells in the CD8<SUP>+</SUP> T-cell population was inversely correlated with the relative frequency of polyfunctional CD8<SUP>+</SUP> T cells. Herein, we demonstrate that HCMV reactivation in severe sepsis patients is associated with PD-1 expression and impaired polyfunctionality of CD8<SUP>+</SUP> T cells.</P>

Extensive Bilateral Lemierre Syndrome due to Methicillin-Resistant Staphylococcus epidermidis in a Patient with Lung Adenocarcinoma

Choi, Bo Mi,Son, Seong Wan,Park, Chan Kwon,Lee, Sang-Hoon,Yoon, Hyung Kyu The Korean Academy of Tuberculosis and Respiratory 2015 Tuberculosis and Respiratory Diseases Vol.78 No.3

Lemierre syndrome (LS) is a septic thrombophlebitis of the internal jugular vein (IJV) following an oropharyngeal infection. LS is commonly caused by normal anaerobic flora and treated with appropriate antibiotics and anticoagulation therapy. Although the incidence of disease is very rare, 15% cases of LS are fatal even in the antibiotic era because of disseminated septic thromboemboli. We reported a case of extensive bilateral LS due to methicillin-resistant Staphylococcus epidermidis in a 63-year-old female with lung adenocarcinoma. Initial examination revealed a retropharyngeal abscess; hence, intravenous ceftriaxone and steroid were initiated empirically. However, pulmonary thromboembolism developed and methicillin-resistant S. epidermidis was identified in the bacterial culture. Despite intensive antibiotic and anticoagulation therapies, extensive septic thrombophlebitis involving the bilateral IJV and superior vena cava developed. Adjunctive catheter-directed thrombolysis and superior vena cava stenting were performed and the patient received antibiotic therapy for an additional 4 weeks, resulting in complete recovery.

Effects of White Mulberry (Morus alba) Leaves on Blood Vessel Reactivity in Hyperchloesterolemic Rats

Choi, Sang-Hoon,Park, Kwan Ha The Korean Society of Food Hygiene and Safety 2013 한국식품위생안전성학회지 Vol.28 No.3

In atherosclerosis, blood vessels become sensitive to vessel-constricting agents leading to reduced control in the event of abrupt blood pressure changes. Mulberry trees (Morus alba L., MA) have been claimed to contain various bioactive principles that could possibly prevent atherosclerosis development caused by high cholesterol consumption. In order to examine whether MA feeding can prevent the sensitization of blood vessels, MA leaves were fed to rats for 8 weeks and pressor responses to vasoconstricting agents were assessed. Animals were pithed before blood pressure assessments to eliminate reflex compensation in vessel responses. Feeding diets containing high levels of cholesterol led to potentiated pressor responses to sympathetic nerve stimulation, or to injection of norepinephrine, phenylephrine, angiotensin II and vasopressin in pithed rats. These potentiated pressor responses were prevented in rats fed MA leaf-containing diets at 2 or 10% levels. It was also examined in anesthetized non-pithed rats whether similar cholestrol-related sensitization and MA prevention could be observed. However, high cholesterol-induced sensitization in pressor responses were not observed, suggesting that destruction of central cardiovascular control by pithing must have revealed the sensitization responses. It was concluded that MA leaves seem to be active in preventing abnormal blood vessel reactivity caused by hypercholesterolemia. 동맥경화 상태에서는 혈관이 수축물질에 예민하게 반응함으로써 혈압의 급격한 변화에 대한 회복능력이 저하한다. 한편 뽕나무 잎에는 고지방식의 섭취로 인해 발생하는 동맥경화증의 발달을 감소시킬 가능성이 있는 여러 물질이 있다고 추정된다. 뽕나무 잎을 백서에 투여하면 고지방식에 의해 유발된 혈관이 예민해지는 현상을 감소시킬 수 있는지 시험하기 위하여 고지방식 및 뽕나무잎을 8주간 투여하고 혈관수축 물질에 대한 혈압의 반응성을 시험하였다. 순환기반사에 따른 혈압반응 감수성차이를 최소화할 목적으로 동물의 중추신경계를 파괴(pithing)하고 시험하였다. 고콜레스테롤을 함유한 식이를 공급한 백서에서 교감신경계 전기자극이나 norepinephrine, phenylephrine, angiotensin II 및 vasopressin 등의 투여로 유발된 혈압상승반응이 증강되었으며, 사료에 뽕잎을 2% 또는 10% 첨가하면 정상적인 혈압상승반응을 보여주었다. 교감신경계를 파괴하지 않은 채 마취만 한 백서에서는 고콜레스테롤에 의한 반응증강이나 뽕잎에 의한 변화를 관찰할 수 없었다. 이 결과로 부터 뽕잎이 동맥경화에서 나타나는 혈관반응성 변화를 방지하는 데 유용한 것으로 판단할 수 있을 것이다.