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>

노지 블루베리 재배를 위한 스마트 관개시스템

김민영 ( Minyoung Kim ),김영훈 ( Younghun Kim ),김상훈 ( Sanghun Kim ),최용훈 ( Yonghun Choi ),전종길 ( Jonggil Jeon ),김영진 ( Youngjin Kim ),서명철 ( Myungchul Seo ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

Due to a growing and aging population in agriculture, the adaptation of labor-saving, computer-controlled automatic irrigation system becomes more essential to increase crop yield and improve its quality. In addition, water shortage is becoming one of the biggest problem in the world, so much attention has been given to search for technologies/measures to save/conserve water from irrigated areas. The aim of this study is to develop an automatic irrigation system which measures timely variant soil moistures and automatically turns on or off the water supply system based on the programmed logics for blueberry outdoor cultivation. This system also provides the crop evapotranspiration calculated based on the weather data from nearby weather station. A soil moisture sensor is periodically interrogated by a pulse signal provided by the microcontroller via a driver or buffer circuit. A microcontroller is coupled in controlling relationship to the solenoid valves in each zone at predetermined times during a day unless the moisture sensor for that given zone indicates a predetermined sufficient level of moisture present. This study showed that the combination of hardware and software provides an irrigation controller that can be implemented at relatively low cost and which is extremely user friendly. Two-year monitoring and one-year field application showed that the automatic irrigation system based on soil moisture and weather data outperformed considering the fruit marketable yield and quality (weight, diameter, sugar content, firmness, etc.), water productivity and labor-saving.

Infrared Estimation of Canopy Temperature as Crop Water Stress Indicator

Kim, Minyoung,Kim, Seounghee,Kim, Youngjin,Choi, Yonghun,Seo, Myungchul Korean Society of Soil Science and Fertilizer 2015 한국토양비료학회지 Vol.48 No.5

Decision making by farmers regarding irrigation is critical for crop production. Therefore, the precision irrigation technique is very important to improve crop quality and yield. Recently, much attention has been given to remote sensing of crop canopy temperature as a crop water-stress indicator, because it is a scientifically based and easily applicable method even at field scales. This study monitored a series of time-variant canopy temperature of cucumber under three different irrigation treatments: under-irrigation (control), optimal-irrigation, and over-irrigation. The difference between canopy temperature ($T_c$) and air temperature ($T_a$), $T_c-T_a$, was calculated as an indicator of cucumber water stress. Vapor pressure deficit (VPD) was evaluated to define water stress on the basis of the temperature difference between leaf and air. The values of $T_c-T_a$ was negatively related to VPD; further, cucumber growth in the under- and over-irrigated fields showed water stress, in contrast to that grown in the optimally irrigated field. Thus, thermal infrared measurements could be useful for evaluating crop water status and play an important role in irrigation scheduling of agricultural crops.

Examination for Evaluating Degradation of Guide Tubes in Spent Fuel Assembly

Myungchul Park,Sunggeun Kim,Jaehan Kim,Sukwoo Hong,Hyojik Lee 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

The skeleton of fuel assembly is composed of top nozzle, bottom nozzle, grids, and guide tubes. In the reactor core, all the parts of the fuel assembly suffer degradations due to the condition of high temperature, pressure and water environment. Therefore, many material properties of high temperature mechanical strength, corrosion and irradiation resistance have been considered to choose the material for fuel assembly parts in the fuel development stage. The guide tubes have important roles to connect each parts and support the load of fuel assembly while the fuel is lifted. In Westinghouse 14×14 standard fuel assembly, Zircaloy-4 was used for the material of the guide tubes. Zircaloy-4 has a resistance to water corrosion and maintain good mechanical properties after the discharge from the core, so this alloy is also utilized for a fuel rod cladding material although the microstructure is slightly different due to the heat treatment difference. Thus, it is expected that there is no issue regarding the guide tube integrity after the discharge and during the storage in the pool, especially in case of low burn-up. However, the surface oxidation and resultant hydrogen pick-up can affect to the embrittlement to the Zr alloy. So, it is needed to know the actual status of spent fuel assembly by performing post-irradiation examination. In this study, the degradation level of the guide Tubes in low burn-up spent fuel assembly was investigated using the KAERI PIE facility in order to make some data which can be utilized to the baseline for evaluating the integrity of the spent fuel skeleton.

Proper Activity of Histone H3 Lysine 4 (H3K4) Methyltransferase Is Required for Morphogenesis during Zebrafish Cardiogenesis

Kim, Jun-Dae,Kim, Eunmi,Koun, Soonil,Ham, Hyung-Jin,Rhee, Myungchull,Kim, Myoung-Jin,Huh, Tae-Lin Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.6

While increasing evidence indicates the important function of histone methylation during development, how this process influences cardiac development in vertebrates has not been explored. Here, we elucidate the functions of two histone H3 lysine 4 (H3K4) methylation enzymes, SMYD3 and SETD7, during zebrafish heart morphogenesis using gene expression profiling by whole mount in situ hybridization and antisense morpholino oligonucleotide (MO)-based gene knockdown. We find both smyd3 and setd7 are highly expressed within developing zebrafish heart and knock-down of these genes led to severe defects in cardiac morphogenesis without altering the expressions pattern of heart markers, including cmlc2, vmhc, and amhc. Furthermore, double knock-down by coinjection of smyd3 and setd7 MOs caused the synergistic defects in heart development. As similar to knock-down effect, overexpression of these genes also caused the heart morphogenesis defect in zebrafish. These results indicate that histone modifying enzymes, SMYD3 and SETD7, appear to function synergistically during heart development and their proper functioning is essential for normal heart morphogenesis during development.

Activation of the Thyroid-Stimulating Hormone β-Subunit Gene by LIM Homeodomain Transcrpition Factor Lhx2

Kim, Kee K.,Song, Seok B.,Kang, Kwang I.,Rhee, Myungchull,Kim, Kyoon Eon 충남대학교 대학원 2006 論文集 Vol.25 No.-

Maintenance of Hydrogen Analyzer for Zr Cladding of Spent Fuel

Myungchul Park,Jaehan Kim,Dosik Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Korea Atomic Energy Research Institute (KAERI) has been operating the Post Irradiation Examination Facility (PIEF). The facility has many PIE equipment and one of them is a hydrogen analyzer for measuring hydrogen contents in Zr cladding of spent fuel. The cladding tube of fuel is oxidized in the core environment of high temperature and pressure and absorbs some of the hydrogen generated during the oxidation. The hydrogen content increases with the increase of burn-up, and causes hydriding of the material, which degrades the mechanical properties. Therefore, hydrogen content analysis of the cladding tube is required for the performance and integrity evaluation of spent fuel. In PIEF, the hydrogen analyzer extracts hydrogen gas from Zr cladding by the hot extraction method. The hydrogen gas flows with inert gas and oxidizes to H2O through a CuO reagent. Finally, an IR detector measures the hydrogen amount from the absorbed IR intensity at a specific wavelength. Because the equipment is in the glove box and has some consumable parts, the maintenance work was performed as a radiation work.

Development of Cutting Machine for Post-irradiation Examination of Spent Fuel Rod in Hot Cell

Myungchul Park,Jaehan Kim,Hyungkwon Lee,Dosik Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Korea Atomic Energy Research Institute (KAERI) has been operating the Post Irradiation Examination Facility (PIEF) for spent fuel. The facility has pools and hot cells for handling and examining fuel assemblies and rods. In the first hot cell, non-destructive tests such as visual inspection, defect detection, oxide layer thickness measurement, and gamma scanning are performed on a full-length fuel rod. Then, the fuel rod is transported to the next hot cell for measuring the rod internal pressure (RIP). After the RIP measurement, the fuel rod is cut by a cutting machine to make samples for destructive tests. Currently, the existing cutting machine is broken, so a new machine needed to be designed and manufactured. The major considerations for designing the cutting machine were convenience of remote handling and decontamination. The machine was modularized and its handling parts were designed to be easily controlled by manipulators. The cover was designed to prevent radioactive contamination of the surrounding area.

Primary cutaneous CD4+ small/medium T-cell lymphoma: a case report

Kim, Jeenam,Jeong, Minkyoung,Jun, Dongkeun,Lee, Myungchul,Shin, Donghyeok,Kim, Wookyoun,Choi, Hyungo Korean Cleft Palate-Craniofacial Association 2021 Archives of Craniofacial Surgery Vol.22 No.4

Primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder is a rare disease characterized by a single mass on the face or upper part of the trunk. It usually presents an asymptomatic and favorable progression, and its histopathologic findings include small and medium-sized lymphoid cells. The authors report a case of primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder on the forehead. A 51-year-old man presented with a protruding mass on his forehead that the patient had noted 1 month previously. Surgical excision and a permanent biopsy were performed under local anesthesia. Based on the biopsy results, the mass was diagnosed as a primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder. There was no evidence of recurrence at a 15-month follow-up visit.

Zebrafish Crip2 Plays a Critical Role in Atrioventricular Valve Development by Downregulating the Expression of ECM Genes in the Endocardial Cushion

Kim, Jun-Dae,Kim, Hey-Jin,Koun, Soonil,Ham, Hyung-Jin,Kim, Myoung-Jin,Rhee, Myungchull,Huh, Tae-Lin Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.5

The initial step of atrioventricular (AV) valve development involves the deposition of extracellular matrix (ECM) components of the endocardial cushion and the endocardialmesenchymal transition. While the appropriately regulated expression of the major ECM components, Versican and Hyaluronan, that form the endocardial cushion is important for heart valve development, the underlying mechanism that regulates ECM gene expression remains unclear. We found that zebrafish crip2 expression is restricted to a subset of cells in the AV canal (AVC) endocardium at 55 hours post-fertilization (hpf). Knockdown of crip2 induced a heart-looping defect in zebrafish embryos, although the development of cardiac chambers appeared to be normal. In the AVC of Crip2-deficient embryos, the expression of both versican a and hyaluronan synthase 2 (has2) was highly upregulated, but the expression of bone morphogenetic protein 4 (bmp4) and T-box 2b (tbx2b) in the myocardium and of notch1b in the endocardium in the AVC did not change. Taken together, these results indicate that crip2 plays an important role in AV valve development by downregulating the expression of ECM components in the endocardial cushion.