A strategy for forming robust adhesion with the substrate in a carbon-nanotube field-emission array

Lim, Seong Chu,Choi, Ha Kyu,Jeong, Hee Jin,Song, Young Il,Kim, Gil Yong,Jung, Kyung Taek,Lee, Young Hee Elsevier 2006 Carbon Vol.44 No.13

<P><B>Abstract</B></P><P>A method of how to form a strong adhesion of carbon nanotubes (CNTs) to substrate by introducing an intermediate metal layer in fabricating spray-based field emitters and its effect to the field-emission properties were addressed. An Indium or tin layer was deposited on an indium-tin-oxide glass substrate and thermally annealed to hold the CNTs tightly. This underlying metal layer forms a strong bond to CNTs by wetting while melting without any detectable evaporation of metal atoms. This gave rise to a stable field-emission current at high voltage, which was confirmed by a mass spectrometer. The tube density and field-emission characteristics strongly depend on the annealing temperature of metal layers.</P>

Dynamic Wedge의 조직내 방사선량 분포의 특성

오영택(Young Taek Oh),금기창(Ki Chang Keum),추성실(Seong Sil Chu),김귀언(Gwi Eon Kim) 대한방사선종양학회 1996 Radiation Oncology Journal Vol.14 No.4

목적 : 방사선 치료에 있어서 조직내 등선량 분포곡선을 변형시킬 목적으로 쐐기 차폐물이 사용되고 있는데 최근 기존의 고정 쐐기와는 다르게 비대칭적인 콜리메이터인 Independent Jaw에 의해 등선량 분포곡선을 변형시키는 동적 쐐기 기법이 실용화 되고 있으나 아직 그 방사선 물리학적인 특성에 대해서는 잘 알려져 있지 않다. 이에 본 저자는 기존의 고정 쐐기와 비교하여 조직내 방사선량 분포의 특성을 알아보고자 본 연구를 계획하였다. 대상 및 방법 : 물 판톰, 폴리 스타이린 판톰, 평균 유방 모형 판톰을 대상으로 전리함, 필름, TLD 등을 이용하여 동적 쐐기와 고정 쐐기의 선량 분포를 측정하여 비교하였다. 방사선원은 선형 가속기의 6MV x선을 사용하였고 15x15 조사면에서 15, 30, 45도 쐐기를 이용하였다 조직내선량 분포는 전리함과 필름 선량계를 사용하였고, 유방 접선 치료방식에서의 반대편 유방 조사선량은 TLD를 사용하였다. 결과 : 1) 조직내 %심도 선량은 고정 쐐기의 경우 심도 선량 깊이가 깊어지는 방사선의 경화 현상이 뚜렷하였으나 동적 쐐기의 경우에는 발견할 수 없었으며 그 % 심도선량은 개방 조사면과 유사하였다. 2) 조직내 등선량 분포 곡선을 보면 동적 쐐기의 경우 고정 쐐기와는 달리 원하는 깊이, 원하는 조사면에서 원하는 쐐기 각도를 얻을 수 있었으며 쐐기 각도를 이루는 등선량 분포 곡선이 고정 쐐기에 비해 더욱 직선적이었다. 3) 산란선량은 동적 쐐기의 경우 개방 조사면과 그 양이 거의 동일하였으며 유방보존술에서의 접선 조사방식의 방사선치료에서 고정 쐐기 대신에 동적 쐐기를 사용함으로써 반대측 유방으로의 피폭선량을 감소시킬 수 있었다. 결론적으로 동적 쫴기 기법은 단순히 고정 쐐기를 대체할 수 있을 뿐만 아니라 고정 쐐기의 단점을 보완해 줄 수 있으며 향후 방사선 치료에 있어서 더 다양한 유용성을 가질 수 있으리라 생각한다. Purpose : The wedge filter is the most commonly used beam modifying device during radiation therapy Recently dynamic wedge technique is available through the computer controlled asymmetric collimator, independent jaw. But dosimetric characteristics of dynamic wedge technique is not well known. Therefore we evaluate dosimetric characteristics of dynamic wedge compared to conventional fixed wedge. Materials and Methods : We evaluated dosimetric characteristics of dynamic wedge and fixed wedge by ion chamber, film dosimetry and TLD in phantoms such as water, polystyrene and average breast phantom. Six MV x-ray was used in 15x15cm field with 15,30 and 45 degree wedge of dynamic/liked wedge system, Dosimeric characteristics are interpreted by Wellhofer Dosimetrie system WP700/WP700i and contralateral breast dose (CBD) with tangential technique was confirmed by TLD. Results : 1) Percent depth dose through the dynamic wedge technique in tissue equivalent phantom was similar to open field irradiation and there was no beam hardening effect compared to fixed wedge technique. 2) Isodose line composing wedge angle of dynamic wedge is more straight than hard wedge. And dynamic wedge technique was able to make any wedge angle on any depth and field size. 3) The contralateral breast dose in primary breast irradiation was reduced by dynamic wedge technique compared to fixed wedge. When the dynamic wedge technique was applied, the scatter dose was similar to that of open field irradiation. Conclusion : The dynamic wedge technique was superior to fixed wedge technique in dosimetric characteristics and may be more useful in the future.

중합체 겔과 자기공명영상을 이용한 3차원 선량분포 측정

오영택(Young-Taek Oh),강해진(Haejin Kang),김미화(Miwha Kim),전미선(Mison Chun),강승희(Seung-Hee Kang),서창옥(Chang Ok Suh),추성실(Seong Sil Chu),성진실(Jinsil Seong),김귀언(Gwi Eon Kim) 대한방사선종양학회 2002 Radiation Oncology Journal Vol.20 No.3

목적 : 최근 중합체 겔과 자기공명영상을 이용한 새로운 선량측정법이 알려졌으며, 이 방법은 기존의 선량측정법과는 달리 3차원적인 선량분포를 측정할 수 있다는 장점이 있다. 이 중합체 겔과 자기공명영상을 이용한 3차원적인 선량측정법의 유용성을 평가하고자 본 연구를 실행하였다. 대상 및 방법 : 산소를 제거하면서 겔 판톰을 만들고, 정해진 방사선량을 조사하였다. 자기공명영상촬영을 하여 조사된 방사선의 3차원 영상 및 횡이완시간(T2 relaxation time)을 구하고, 횡이완시간과 방사선량과의 함수관계를 구하였다. 구 모양의 겔 판톰을 제작하여 모의 방사선치료계획에 따라 방사선을 조사하고, 같은 방법으로 화소 당 횡이완시간을 구하고 그에 따른 3차원 선량분포도를 구한 다음 치료계획용 컴퓨터를 이용한 선량분포도와 비교하였다. 또한 같은 모의 방사선치료계획으로 Gaf-chromic 필름과 TLD를 이용하여 선량을 측정하고, 중합체 겔을 이용한 선량측정법과 기존 선량측정법과의 장단점을 비교 분석하였다. 결과 : 중합체 겔의 횡이완시간 및 그 역수와 방사선량은 2 Gy에서 15 Gy의 구간에서 선형의 함수관계를 이루고 있으며, 중합체 겔과 자기공명영상을 이용하여 3차원적인 선량분포를 구할 수 있었다. 매 측정 시마다 그 등선량곡선이 일정하여 측정 결과는 매우 안정적이었다. 이 중합체 겔 선량측정법은 치료계획 상의 선량분포와 거의 일치하였고, 절대선량과 깊이선량율에서 겔 선량측정법은 Gaf-chromic 필름 선량계 및 TLD 선량계와 치료계획상의 선량분포를 기준으로 할 때 그 정확도에서 비슷하거나 우월하였다. 결론 : 중합체 겔과 자기공명영상을 이용한 선량측정법은 아직 초기로 많은 개선점이 있으나 Gaf-chromic 선량측정법과 비슷하거나 우월한 정확성을 가지고 있을 뿐만 아니라 3차원적인 선량분포를 보여줄 수 있는 큰 장점을 가지고 있어, 3차원적인 선량분포를 이용하는 방사선치료에서 유용한 선량측정법으로 판단되며, 향후 임상적인 연구가 필요할 것으로 판단되었다. Purpose : Three-dimensional radiation dosimetry using magnetic resonance imaging of polymer gel was recently introduced. This dosimetry system is based on radiation induced chain polymerization of acrylic monomers in a muscle equivalent gel and provide accurate 3 dimensional dose distribution. We planned this study to evaluate the clinical value of this 3-dimensional dosimetry. Materials and Methods: The polymer gel poured into a cylindrical glass flask and a spherical glass flask. The cylindrical test tubes were for dose response evaluation and the spherical flasks, which is comparable to the human head, were for isodose curves. T2 maps from MR images were calculated using software, IDL. Dose distributions have been displayed for dosimetry. The same spherical flask of gel and the same irradiation technique was used for film and TLD dosimetry and compared with each other. Results : The R2 of the gel respond linearly with radiation doses in the range of 2 to 15 Gy. The repeated dosimetry of spherical gel showed the same isodose curves. These isodose curves were identical to dose distributions from treatment planning system especially high dose range. In addition, the gel dosimetry system showed comparable or superior results with the film and TLD dosimetry. Conclusion : The 3-dimensional dosimetry for conformal radiation therapy using MRI of polymer gal showed stable and accurate results. Although more studies are needed for convenient clinical application, it appears to be a useful tool for conformal radiation therapy.

Metastatic endophthalmitis and thyroid abscess complicating Klebsiella pneumoniae liver abscess

( Seon-jae Kim ),( Seong Taek Chu ),( Keun Sook Lee ),( Seung Woo Nam ),( Jong Kyoung Choi ),( Joo Won Chung ),( Hyeok Choon Kwon ) 대한간학회 2018 Clinical and Molecular Hepatology(대한간학회지) Vol.24 No.1

The thyroid is resistant to infection due to its anatomical and physiological characteristics. We present a rare case of invasive liver abscess with metastatic thyroid abscess and endogenous endophthalmitis in a previously healthy 55-yearold female patient without diabetes or other medical illness. This report raises an important question of the virulence of Klebsiella pneumoniae as an increasingly common causative agent of liver abscess. (Clin Mol Hepatol 2018;24:88-91)

A rare case of hyperoxaluria presenting with acute liver injury and stone-free kidney injury

( Si Eun Kim ),( Seon Jae Kim ),( Seong Taek Chu ),( Seung Hee Yang ),( Yon Su Kim ),( Ran Hui Cha ) 대한신장학회 2015 Kidney Research and Clinical Practice Vol.34 No.2

A 49-year-old woman visited the clinic because of acute hepatitis and acute kidney injury with decreased urine output presenting microscopic hematuria and proteinuria. An abdominal computed tomography revealed a localized, hypoattenuated lesion in a hepatic lateral segment, and kidney biopsy showed oxalate crystal deposition with tubular necrosis. In addition, the patient``s 24-hour urinary excretion of oxalate was increased. Her kidney and liver injury improved after sessions of hemodialysis, and urinary oxalate excretion was normalized. Major mutations in primary hyperoxaluria have not been proven. A full sequencing of target genes may be helpful to diagnose a rare form of primary hyperoxaluria.

S-238 : 반복된 실신으로 발현한 비소세포 폐암 1예

( Seon Jae Kim ),( Jung A,Koh ),( Hak Chul Lee ),( Si Eun Kim ),( Seong Taek Chu ),( Jung Ju Sir ),( Seung Min Choi ),( Shin Bae Joo ),( Hong Soon Lee ),( Chang In Seo ) 대한내과학회 2013 대한내과학회 추계학술대회 Vol.2013 No.1

Although syncope is a common problem, lung cancer rarely presents with episodic syncope. We herein report a case of syncope as the initial presentation of the mediastinal lung cancer. A 54-year-old man presented to the emergency department after episode of syncope. On arrival, His blood pressure was 60/39 mmHg and pulse rate was 35 beats per minute. The 12 leads electrocardiogram showed marked sinus bradycardia with 2:1 degree AV block. After treatment with intravenous administration of atropine and isoproterenol infusion, he recovered. The image studies revealed mediastinal tumor with lympadenopathy which was pathologically confirmed as the adenocarcinoma of lung cancer. He was treated with chemotherapy and radiation therapy and no further syncopal attacks were observed. This case emphasizes the importance of an appropriate evaluation and broad differential diagnosis for patients with episode of syncope.

Poster Session:PS 1187 ; Cardiology : The Prognostic Value of CA-125 Levels in Patients with Acute Decompensated Heart Failure: Correlation with Clinical and Echocardiographic Parameters

( Jung A Koh ),( Seon Jae Kim ),( Hak Chul Lee ),( Seong Taek Chu ),( Si Eun Kim ),( Seung Min Choi ),( Shin Bae Joo ),( Jung Ju Sir ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Serum carbohydrate antigen 125 (CA-125), known as a tumor marker, has been reported to be a prognostic indicator of acute decompensated heart failure (ADHF). The aim of this study was to investigate the prognostic value of serum CA-125 levels on admission in patients with ADHF due to ischemic and non-ischemic etiologies. Methods: We prospectively studied 110 patients admitted with ADHF from ischemic heart disease 51(46%), hypertensive cardiomyopathy 4(4%), dilated cardiomyopathy 16(15%), atrial fibrillation 24 (22%), valvular heart disease 8(7%), Cor pulmonale 3(3%), congenital heart disease 2 (2%), hypertrophic cardiomyopathy 1(1%), stress-induced cardiomyopathy 1 (1%). All patients underwent transthoracic echocardiographic study and measurement of serum CA-125 and NT-proBNP on admission. Results: The median (interquartile range) levels of CA-125 on admission were signifi - cantly higher according to the severity of HF symptoms (13. 0 (9. 1-28. 7) vs. 47. 6 (15. 1- 156. 9) vs. 58. 0 (22. 52-192. 5) U/ml for NYHA FC II/III/IV, respectively; p=0. 001). There were statistically signifi cant correlations between CA-125 levels and NT-proBNP, free T4, T3, LV EF (calculated by biplane method), LVEDD, LAVI, DT, and RV systolic pressure (r = 0. 514, 0. 228, -0. 391, -0. 376, 0. 254, -0. 523, 0. 420, 0. 401, respectively, all with P < 0. 05). Patients with cardiovascular deaths + re-hospitalizations had signifi cantly higher serum CA-125 levels on admission than those without (53. 2 (16. 6-175. 1) vs. 28. 2 (11. 2-91. 0) U/ml, respectively, p<0. 05). Analysis of receiver operating characteristic curves identifi ed CA-125 level for increased risk of adverse cardiac events (AUC=0. 651; p=. 0. 23; optimal cut-off value: 43. 9 U/ml). Conclusions: In this heterogeneous group of patients hospitalized with ADHF, CA-125 levels have prognostic value with respect to short-term mortality and re-hospitalization. This study indicated that CA-125 could serve as prognostic biomarker of heart failure, although the pathophysiology remains to be established.

Poster Session : PS 1392 ; Nephrology : A Rare Case of Hyperoxaluria Presenting with Liver Dysfunction and Stone-Free Kidney Injury

( Si Eun Kim ),( Ran Hui Cha ),( Seon Jae Kim ),( Seong Taek Chu ),( Seung Hee Yang ),( Yon Su Kim ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Oxalate nephropathy is an unusual cause of acute or chronic renal failure. Hyperoxaluria can develop in patients with inborn disorders of oxalate metabolism (primary hyperoxaluria) or secondary to other diseases (secondary hyperoxaluria). Hyperoxaluria accompanied by acute hepatitis has not been previously reported. We report a patient with acute kidney injury accompanied with acute hepatitis and hyperoxaluria. Case presentation: A 49-year-old Asian woman visited the clinic because of acute hepatitis and oliguric acute kidney injury presenting microscopic hematuria and proteinuria. She denied having any previous medical problems, use of regular medications, or intake of unusual foods or beverages. Laboratory values were as follows: BUN 81 mg/dL, serum creatinine 11.4 mg/dL, SGOT 695 U/L, SGPT 1,181 U/L, total bilirubin 1.2 mg/dL, INR 0.97. An abdominal CT revealed a localized, hypo-attenuated lesion in a hepatic lateral segment, and kidney biopsy showed oxalate crystal deposition with tubular necrosis. In addition, the patient`s 24-hour urinary excretion of oxalate was increased [oxalate 68 mg/24 hours (reference: 4-31 mg/24 hours)]. Her renal function and liver injury improved after several sessions of hemodialysis and urinary oxalate excretion was normalized. A genetic analysis for major mutations associated with primary hyperoxaluria types 1 and 2 was performed. There were no meaningful mutations. Discussion: If crystal deposition is found on the kidney biopsy without any evidence of other renal diseases, oxalosis should be considered, and appropriate evaluations, including urine oxalate excretion, should be performed. If secondary hyperoxaluria can be excluded, primary hyperoxaluria should be considered to be a possibility, and evaluations, including genetic analysis, should be performed. Also, additional studies on the temporary dysfunction of liver-specific enzymes due to hepatitis as a cause of increased oxalate formation could be of broader interest.

Comprehensive RNA-sequencing analysis of colorectal cancer in a Korean cohort

Jaeim Lee,Jong-Hwan Kim,Hoang Bao Khanh Chu,Seong-Taek Oh,Sung-Bum Kang,Sejoon Lee,Duck-Woo Kim,Heung-Kwon Oh,Ji-Hwan Park,Jisu Kim,Jisun Kang,Jin-Young Lee,Sheehyun Cho,Hyeran Shim,Hong Seok Lee,Seon Korean Society for Molecular and Cellular Biology 2024 Molecules and cells Vol.47 No.3

Considering the recent increase in the number of colorectal cancer (CRC) cases in South Korea, we aimed to clarify the molecular characteristics of CRC unique to the Korean population. To gain insights into the complexities of CRC and promote the exchange of critical data, RNA-sequencing analysis was performed to reveal the molecular mechanisms that drive the development and progression of CRC; this analysis is critical for developing effective treatment strategies. We performed RNA-sequencing analysis of CRC and adjacent normal tissue samples from 214 Korean participants (comprising a total of 381 including 169 normal and 212 tumor samples) to investigate differential gene expression between the groups. We identified 19,575 genes expressed in CRC and normal tissues, with 3,830 differentially expressed genes (DEGs) between the groups. Functional annotation analysis revealed that the upregulated DEGs were significantly enriched in pathways related to the cell cycle, DNA replication, and IL-17, whereas the downregulated DEGs were enriched in metabolic pathways. We also analyzed the relationship between clinical information and subtypes using the Consensus Molecular Subtype (CMS) classification. Furthermore, we compared groups clustered within our dataset to CMS groups and performed additional analysis of the methylation data between DEGs and CMS groups to provide comprehensive biological insights from various perspectives. Our study provides valuable insights into the molecular mechanisms underlying CRC in Korean patients and serves as a platform for identifying potential target genes for this disease. The raw data and processed results have been deposited in a public repository for further analysis and exploration.

Exploring the DNA methylome of Korean patients with colorectal cancer consolidates the clinical implications of cancer-associated methylation markers

( Sejoon Lee ),( Kil-yong Lee ),( Ji-hwan Park ),( Duck-woo Kim ),( Heung-kwon Oh ),( Seong-taek Oh ),( Jongbum Jeon ),( Dongyoon Lee ),( Soobok Joe ),( Hoang Bao Khanh Chu ),( Jisun Kang ),( Jin-youn 생화학분자생물학회 2024 BMB Reports Vol.57 No.3

Aberrant DNA methylation plays a critical role in the development and progression of colorectal cancer (CRC), which has high incidence and mortality rates in Korea. Various CRC-associated methylation markers for cancer diagnosis and prognosis have been developed; however, they have not been validated for Korean patients owing to the lack of comprehensive clinical and methylome data. Here, we obtained reliable methylation profiles for 228 tumor, 103 adjacent normal, and two unmatched normal colon tissues from Korean patients with CRC using an Illumina Infinium EPIC array; the data were corrected for biological and experiment biases. A comparative methylome analysis confirmed the previous findings that hypermethylated positions in the tumor were highly enriched in CpG island and promoter, 5’ untranslated, and first exon regions. However, hypomethylated positions were enriched in the open-sea regions considerably distant from CpG islands. After applying a CpG island methylator phenotype (CIMP) to the methylome data of tumor samples to stratify the CRC patients, we consolidated the previously established clinicopathological findings that the tumors with high CIMP signatures were significantly enriched in the right colon. The results showed a higher prevalence of microsatellite instability status and MLH1 methylation in tumors with high CMP signatures than in those with low or non-CIMP signatures. Therefore, our methylome analysis and dataset provide insights into applying CRC-associated methylation markers for Korean patients regarding cancer diagnosis and prognosis. [BMB Reports 2024; 57(3): 161-166]