Antagonistic regulation of PAF1C and p-TEFb is required for oligodendrocyte differentiation.

Kim, Suhyun,Kim, Jun-Dae,Chung, Ah-Young,Kim, Hyung-Seok,Kim, Young-Seop,Kim, Myoung-Jin,Koun, Soonil,Lee, You Mie,Rhee, Myungchull,Park, Hae-Chul,Huh, Tae-Lin The Society 2012 The Journal of neuroscience Vol.32 No.24

<P>Oligodendrocytes are myelinating glial cells in the CNS and are essential for proper neuronal function. During development, oligodendrocyte progenitor cells (OPCs) are specified from the motor neuron precursor domain of the ventral spinal cord and differentiate into myelinating oligodendrocytes after migration to the white matter of the neural tube. Cell cycle control of OPCs influences the balance between immature OPCs and myelinating oligodendrocytes, but the precise mechanism regulating the differentiation of OPCs into myelinating oligodendrocytes is unclear. To understand the mechanisms underlying oligodendrocyte differentiation, an N-ethyl-N-nitrosourea-based mutagenesis screen was performed and a zebrafish leo1 mutant, dalmuri (dal(knu6)) was identified in the current study. Leo1 is a component of the evolutionarily conserved RNA polymerase II-associated factor 1 complex (PAF1C), which is a positive regulator of transcription elongation. The dal(knu6) mutant embryos specified motor neurons and OPCs normally, and at the appropriate time, but OPCs subsequently failed to differentiate into myelinating oligodendrocytes and were eliminated by apoptosis. A loss-of-function study of cdc73, another member of PAF1C, showed the same phenotype in the CNS, indicating that PAF1C function is required for oligodendrocyte differentiation. Interestingly, inhibition of positive transcription elongation factor b (p-TEFb), rescued downregulated gene expression and impaired oligodendrocyte differentiation in the dal(knu6) mutant and Cdc73-deficient embryos. Together, these results indicate that antagonistic regulation of gene expression by PAF1C and p-TEFb plays a crucial role in oligodendrocyte development in the CNS.</P>

CXXC5 is a transcriptional activator of <i>Flk-1</i> and mediates bone morphogenic protein-induced endothelial cell differentiation and vessel formation

Kim, Hyun-Yi,Yang, Dong-Hwa,Shin, Song-Weon,Kim, Mi-Yeon,Yoon, Jae-Hyun,Kim, Suhyun,Park, Hae-Chul,Kang, Dong Woo,Min, DoSik,Hur, Man-Wook,Choi, Kang-Yell The Federation of American Societies for Experimen 2014 The FASEB Journal Vol.28 No.2

<P>CXXC5 is a member of a small subset of proteins containing CXXC-type zinc-finger domain. Here, we show that CXXC5 is a transcription factor activating <I>Flk-1</I>, a receptor for vascular endothelial growth factor. CXXC5 and Flk-1 were accmulated in nucli and membrane of mouse embryonic stem cells (mESCs), respectively, during their endothelial differentiation. CXXC5 overexpression induced <I>Flk-1</I> transcription in both endothelium-differentiated mESCs and human umbilical vein endothelial cells (HUVECs). <I>In vitro</I> DNA binding assay showed direct interaction of CXXC5 on the <I>Flk-1</I> promoter region, and mutation on its DNA-binding motif abolished transcriptional activity. We showed that bone morphorgeneic protein 4 (BMP4) induced <I>CXXC5</I> transcription in the cells, and inhibitors of BMP signaling suppressed the <I>CXXC5</I> induction and the consequent <I>Flk-1</I> induction by BMP4 treatment. <I>CXXC5</I> knockdown resulted in suppression of BMP4-induced stress fiber formation (56.8±1.3% decrease, <I>P</I><0.05) and migration (54.6±1.9% decrease, <I>P</I><0.05) in HUVECs. The <I>in vivo</I> roles of CXXC5 in BMP-signaling-specific vascular development and angiogenesis were shown by specific defect of caudal vein plex vessel formation (57.9±11.8% decrease, <I>P</I><0.05) in <I>cxxc5</I> morpholino-injected zebrafish embryos and by supression of BMP4-induced angigogensis in subcutaneously injected Matrigel plugs in <I>CXXC5</I><SUP>−/−</SUP> mice. Overall, CXXC5 is a transcriptional activator for <I>Flk-1</I>, mediating BMP signaling for differentiation and migration of endothelial cell and vessel formation.—Kim, H.-Y., Yang, D.-H., Shin, S.-W., Kim, M.-Y., Yoon, J.-H., Kim, S., Park, H.-C., Kang, D. W., Min, D., Hur, M.-W., Choi, K.-Y. CXXC5 is a transcriptional activator of <I>Flk-1</I> and mediates bone morphogenic protein-induced endothelial cell differentiation and vessel formation.</P>

金謹行(김근행)의 「律呂新書箚疑(율려신서차의)」에 대한 연구

김수현 ( Suhyun Kim ) 한국음악사학회 2015 한국음악사학보 Vol.54 No.-

이 논문은 지금까지 연구가 없었던 조선후기 지식인의 한 사람인 김근행(金謹行, 1712~1782)이 쓴 「율려신서차의」(律呂新書箚疑)를 분석하여 당시 지식인들의 악률(樂律) 인식을 고찰하고자 한 것이다. 김근행의 「율려신서차의」는 1745년경에 쓰여진 것으로 중국 송대 채원정(蔡元定, 1135~1198)이 저술한 악률서 『율려신서』(律呂新書)에서 의심나는 부분을 논한 것이다. 『율려신서』 중의 「律呂本原」 1장에서 10장까지를 다루었는데, 그 서술 특징은 『율려신서』에서 그동안 논쟁이 되었던 핵심적인 부분을 한 편당 주제로 정하여 그 주제에서 이해하기 어려운 부분을 도상으로 보여주고 부연설명을 했다는데 있다. 이 「율려신서차의」에서 다루고 있는 도상은 10개인데 그것은 다음과 같다. ① 圓田開方得포徑圖 ② 黃鍾數法用九圖 ③ 十二律損益得寸圖 ④ 陰陽律當位居沖圖 ⑤ 置一六三圖 ⑥ 五音隔一隔二圖 ⑦ 五音二變成七圖 ⑧ 十二律七聲循環成曲圖 ⑨ 十二律半聲變律圖 ⑩ 五絃琴黃鍾一曲圖이다. 김근행(金謹行)의 「율려신서차의」(律呂新書箚疑)는 『율려신서』를 단순 번역한 것이 아니라 『율려신서』에서 가장 논란이 되는 부분만을 적출해 내서 어떻게 이해해야 하는지 도상과 간결한 설명으로 이해할 수 있게 서술했다는 점에 그 특징이 있다. 이 점은 김근행이 『율려신서』를 비판적으로 논하지 않았고 오히려 채원정의 의도를 간파하여 분명하게 드러내주었음을 의미한다. 이 「율려신서차의」의 분석을 통해서 알 수 있는 사실은 『율려신서』에 대한 이해와 악률에 대한 인식은 매우 높았다는 점이다. 그러나 김근행은 채원정(蔡元定)이 『율려신서』에서 제기한 철학적 의미 등에 대해서는 전혀 언급하고 있지 않았고, 음악의 원리라든가 조(調)의 형성과 관련된 음악이론적 문제만을 다루었다는 한계가 있다. This paper studies on the Yullyo sinso 『律呂新書』 (Lu-lu hsin-shu in Chinese) ch`aui 箚疑 written by Kim Kun-haeng 金謹行 (1712~1782) who was an intellectuals in the Late Choson period. By analyzing the text, it is intended to understand the cognition of the angnyul 樂律 (music theory) at that time. In this book, He dealt with the controversial issues of Yullyo sinso 『律呂新書』 (Lu-lu hsin-shu), which book was written by Ch`ae Won-jong 蔡元定(Ts`ai Yuan-ting in Chinese, 1135~1198) at Sung China. Kim Kun-haeng wrote this book in 1745. He did not criticized Yullyo sinso (Lu-lu hsin-shu), but selected 10 thorny issues; one for each volumes of Yullyo sinso and gave full details of debatable issues. This means he want to clarify Tsai Yuan-ting`s theory. Also, he was well acquainted with contents of Yullyo sinso and Tsai Yuan-ting`s music theory. For all this, Kim Kun-haeng did not make mention of any philosophical point of the Yullyo sinso, but just pointed music theory and some issues of fundamental tonality. That was the critical point of the Yullyo sinso.

등온반응기와 단열반응기 조합으로 구성된 0.25 MW급 메탄합성 파일롯 공정 운전특성

김수현(Suhyun Kim),유영돈(Youngdon Yoo),강석환(Sukhwan Kang),류재홍(Jaehong Ryu),김진호(Jinho Kim),김문현(Munhyun Kim),고동준(Dongjun Koh),이현정(Hyunjung Lee),김광준(Gwangjun Kim),김형택(Hyungtaek Kim) 한국청정기술학회 2013 청정기술 Vol.19 No.2

본 연구에서는 등온반응기와 단열반응기로 구성된 0.25 MW 메탄합성 파일롯 공정 실험을 통한 운전 특성을 분석하였다. 등온반응기는 메탄합성 반응을 통해 발생하는 열을 포화수의 유량과 압력을 통해 강제적으로 제어할 수 있는 반응기로 등온반응기와 단열반응기를 조합할 경우 기존 단열반응기만으로 구성된 메탄합성 공정에 비해 반응기 개수를 줄일 수 있다. 또한 합성가스 재순환이 불필요하기 때문에 단열반응기 조합으로 구성된 메탄합성 공정에서 비용의 약 15~20%를 차지하는 재순환 압축기를 제거할 수 있다. 등온반응기로 유입되는 합성가스의 H2/CO 비가 3보다 낮은 경우에는 튜브에 충진된 촉매에 탄소 침적 현상이 일어나 반응기의 차압이 증가하였으며, H₂/CO 비가 3으로 공급되는 경우에는 탄소 침적 현상이 일어나지 않고 메탄합성 반응이 안정적으로 유지되어 CO 전환율 99% 이상, CH₄ 선택도 97% 이상, CH₄ 생산성 최대 695 ml/h·-cat를 얻을 수 있었다. In this study, we analyzed the operational characteristics of a 0.25 MW methanation pilot plant. Isothermal reactor controled the heat released from methanation reaction by saturated water in shell side. Methanation process consisting of isothermal reactor and adiabatic reactor had advantages with no recycle compressor and more less reactors compared with methanation process with only adiabatic reactors. In case that H2/CO ratio of syngas was under 3, carbon deposition occurred on catalyst in tube side of isothermal reactor and the pressure of reactors increased. In case that H₂/CO ratio was maintained around 3, no carbon deposition on catalyst in tube side of isothermal reactor was found by monitoring the differential pressure of reactors and by measuring the differential pressure of several of tubes filled with catalyst before and after operating. It was shown that CO conversion and CH₄ selectivity were over 99, 97%, respectively, and the maximum CH₄ productivity was 695 ml/h·g-cat.

Auto-Masked Surface Texturing of Kerf-Loss Free Silicon Wafers Using Hexafluoroisopropanol in a Capacitively Coupled Plasma Etching System

Kim, Suhyun,Park, Jin-Su,Kim, Jun-Hyun,Kim, Chang-Koo,Kim, Jihyun Electrochemical Society 2019 ECS journal of solid state science and technology Vol.8 No.4

<P>As the solar cell industry grows and receives worldwide attention for its sustainability, the consideration for its environmental impact becomes inevitable. The high global warming potential (GWP) of the fluorinated gases commonly used in a plasma processing is a significant environmental issue that needs to be addressed. Substituting the high GWP etchants with alternative gases could be an effective solution in plasma etching. Hexafluoroisopropanol (HFIP) not only has relatively low GWP and short atmospheric lifetime, but is also suitable for forming dense nanostructures on the silicon substrate. The morphology of the nanostructures fabricated on kerf-loss free (KLF) silicon substrates was changed by controlling the DC bias voltage of the capacitively coupled plasma etching system. The resulting reflectance spectra shows that HFIP/O<SUB>2</SUB> plasma etching is highly effective in reducing the optical reflectivity loss of the silicon wafers. The suggested dry processing of KLF silicon wafers could improve both industrial and environmental sustainability of solar cell production.</P>

Highly uniform and reliable resistive switching characteristics of a Ni/WO_x/p⁺-Si memory device

Kim, Tae-Hyeon,Kim, Sungjun,Kim, Hyungjin,Kim, Min-Hwi,Bang, Suhyun,Cho, Seongjae,Park, Byung-Gook Elsevier 2018 Solid-State Electronics Vol.140 No.-

<P><B>Abstract</B></P> <P>In this paper, we investigate the resistive switching behavior of a bipolar resistive random-access memory (RRAM) in a Ni/WO<SUB>x</SUB>/p<SUP>+</SUP>-Si RRAM with CMOS compatibility. Highly unifrom and reliable bipolar resistive switching characteristics are observed by a DC voltage sweeping and its switching mechanism can be explained by SCLC model. As a result, the possibility of metal-insulator-silicon (MIS) structural WO<SUB>x</SUB>-based RRAM’s application to Si-based 1D (diode)–1R (RRAM) or 1T (transistor)–1R (RRAM) structure is demonstrated.</P>

Survey of Faint Quasar candidates at 4.7 ≤ z ≤ 5.2

Suhyun Shin,Myungshin Im,Yongjung Kim,Minhee Hyun,Woojin Park,Tae-geun Ji,Yiseul Jeon,Minjin Kim,Dohyeong Kim,Jae-Woo Kim,Yoon Chan Taak,Yongmin Yoon,Changsu Choi,Jueun Hong,Hyunsung David Jun,Marios 한국천문학회 2018 天文學會報 Vol.43 No.1

Reducing the Optical Reflectance of Kerf-Loss Free Silicon Wafers via Auto-Masked CF₄/O₂ Plasma Etch

Kim, Suhyun,Kim, Jun-Hyun,Kim, Jihyun,Kim, Chang-Koo The Electrochemical Society 2018 ECS journal of solid state science and technology Vol.7 No.5

<P>the etch rate of the plasma-etched KLF silicon wafers were investigated. The reduction in the measured reflectivity demonstrated the effectiveness of the auto-masked texturing process on a KLF silicon wafer. These results will eventually attribute to providing cost-effective silicon solar cells. (C) 2018 The Electrochemical Society.</P>

Tcf3 function is required for the inhibition of oligodendroglial fate specification in the spinal cord of zebrafish embryos

Kim, Suhyun,Chung, Ah-Young,Kim, Dohyun,Kim, Young-Seop,Kim, Hyung-Seok,Kwon, Hyung-Wook,Huh, Tae-Lin,Park, Hae-Chul Springer-Verlag 2011 Molecules and cells Vol.32 No.4

Clinical Characteristics and Outcomes of COVID-19 Cohort Patients in Daegu Metropolitan City Outbreak in 2020

Kim Shin-Woo,Kim Seung-Mee,Kim Yu Kyung,Kim Jong-yeon,Lee Yu-Mi,Kim Bong-Ok,Hwangbo Suhyun,Park Taesung 대한의학회 2021 Journal of Korean medical science Vol.36 No.1

Background: A coronavirus disease 2019 (COVID-19) outbreak started in February 2020 and was controlled at the end of March 2020 in Daegu, the epicenter of the coronavirus outbreak in Korea. The aim of this study was to describe the clinical course and outcomes of patients with COVID-19 in Daegu. Methods: In collaboration with Daegu Metropolitan City and Korean Center for Diseases Control, we conducted a retrospective, multicenter cohort study. Demographic, clinical, treatment, and laboratory data, including viral RNA detection, were obtained from the electronic medical records and cohort database and compared between survivors and non-survivors. We used univariate and multi-variable logistic regression methods and Cox regression model and performed Kaplan–Meier analysis to determine the risk factors associated with the 28-day mortality and release from isolation among the patients. Results: In this study, 7,057 laboratory-confirmed patients with COVID-19 (total cohort) who had been diagnosed from February 18 to July 10, 2020 were included. Of the total cohort, 5,467 were asymptomatic to mild patients (77.4%) (asymptomatic 30.6% and mild 46.8%), 985 moderate (14.0%), 380 severe (5.4%), and 225 critical (3.2%). The mortality of the patients was 2.5% (179/7,057). The Cox regression hazard model for the patients with available clinical information (core cohort) (n = 2,254) showed the risk factors for 28-day mortality: age > 70 (hazard ratio [HR], 4.219, P = 0.002), need for O2 supply at admission (HR, 2.995; P = 0.001), fever (> 37.5°C) (HR, 2.808; P = 0.001), diabetes (HR, 2.119; P = 0.008), cancer (HR, 3.043; P = 0.011), dementia (HR, 5.252; P = 0.008), neurological disease (HR, 2.084; P = 0.039), heart failure (HR, 3.234; P = 0.012), and hypertension (HR, 2.160; P = 0.017). The median duration for release from isolation was 33 days (interquartile range, 24.0–46.0) in survivors. The Cox proportional hazard model for the long duration of isolation included severity, age > 70, and dementia. Conclusion: Overall, asymptomatic to mild patients were approximately 77% of the total cohort (asymptomatic, 30.6%). The case fatality rate was 2.5%. Risk factors, including older age, need for O2 supply, dementia, and neurological disorder at admission, could help clinicians to identify COVID-19 patients with poor prognosis at an early stage.