• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.643-649
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• 2017

심장 이온통로의 변화는 활동전압의 모양과 길이에 영향을 주어 심부정맥을 유발한다. 산화적 스트레스의 증가로 인해 생체에 침착이 증가하는 지질산화물 (4-HNE, 4-ONE)는 여러 단백질 및 이온통로에 영향을 주는 독성이차전달자로 알려져 있다. 본 연구자는 선행 연구를 통해 4-HNE와 4-ONE의 단기간 노출이 심실근세포에 발현되는 3종류의 이온통로 ($I_{Kr}$, $I_{Ks}$, $I_{Ca,L}$)의 전류감소와 kinetics변화를 일으키고, 심실근세포의 활동전압길이가 증가하는 것을 확인하였다. 두 물질이 이온통로들에 준 영향은 유사하였으나, 활동전압길이의 증가 정도가 4-ONE에서 더 크게 나타났다. 활동전압의 연장에 차이가 나는 원인과, 두 지질산화물이 또 다른 이온통로에 미치는 영향 유무를 예측하기 위해서 Grandi and Bers human ventricular model[1]을 적용한 Integrated human ventricular myocyte model 프로그램 (developed by prof. Youm)을 활용하였다. 시뮬레이션으로 재현한 4-HNE와 4-ONE에 의한 활동전압은 실험으로 기록된 것보다 연장 정도가 작았다. 시뮬레이션 모델의 background $Na^+$ 전류의 크기를 크게 하였을 경우, 실험에서 기록된 활동전압 길이에 상응하는 연장을 가져왔다. 그러므로, 4-HNE와 4-ONE는 실험으로 확인한 $I_{Kr}$, $I_{Ks}$, $I_{Ca,L}$ 이외에 심장세포에 존재하는 내향전류 (Late $Na^+$ current)의 크기를 증가하는 효과가 있음을 예측할 수 있으며, 실험적 검증이 요구된다.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.275-283
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• 2019

Rare isotope beam facilities require shielding data in early stage of their design. There is much less shielding data on neutrons from the reactions between heavy ion beams and matter than the data on neutrons produced by protons. The purpose of the present work is to produce and thus increase the amount of shielding data on neutrons generated by high-energy heavy ion beams based on the RAON in-flight fragment facility. Calculations were performed with the computational Monte Carlo codes PHITS and MCNPX. The secondary neutron source terms were evaluated at 550 MeV/u for Ca, Kr, and Sn and at 400 MeV/u for U ions on a graphite target. Source terms and attenuation lengths were obtained by fitting the ambient dose equivalent inside an ordinary concrete shield.

• Molecules and Cells
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• v.22 no.1
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• pp.58-64
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• 2006

WRKY family proteins are a class of plant-specific transcription factors involved in stress response signaling pathways. In this study a gene encoding a putative WRKY protein was isolated from a pepper EST database (http://genepool.kribb.re.kr). The cDNA, named Capsicum annuum WRKY2 (CaWRKY2), encodes a putative polypeptide of 548 amino acids, containing two WRKY domains with zinc finger motifs and two potential nuclear localization signals. Northern blot analyses showed that CaWRKY2 mRNA was preferentially induced during incompatible interactions of pepper plants with PMMoV, Pseudomonas syringae pv. syringae 61, and Xanthomonas axonopodis pv. vesicatoria race 3. Furthermore, CaWRKY2 transcripts were strongly induced by wounding and ethephon treatment, whereas only moderate expression was detected following treatment with salicylic acid and jasmonic acid. CaWRKY2 was translocated to the nucleus when a CaWRKY2-smGFP fusion construct was expressed in onion epidermal cells. CaWRKY2 also had transcriptional activation activity in yeast. Taken together our data suggest that CaWRKY2 is a pathogen-inducible transcription factor that may have a role in early defense responses to biotic and abiotic stresses.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2004.05a
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• pp.231-231
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• 2004

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.57-66
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• 2010

CAS Client personalization means to issue CAS ID or Key for CAS service, which is Core Technology for CAS operation. Protocol A.1 on TTA.KR-07.0079 XCAS, stores CAS Client personalization data from CAS server in XCAS server, and transmits the personalization data by request of XCAS HOST for CAS Client personalization. However, this may increase Network Traffic and CAS Client image management in XCAS server. In this thesis, to complement this, CAS Client personalization is executed on CAS Server by separating CAS service field. Therefore this can distribute Image management and Network Traffic of XCAS server.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.588-592
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• 2015

Soil testing is one of the major strategies for establishing sustainable agricultural practice as it analyzes nutrient contents of soil and determines the amount of nutrients required for crop growth. Soil testing for the field cultivating regional major crops in Korea has been conducting by National Academy of Agricultural Science (NAAS), provincial agricultural research & extension services and agriculture technology centers since 2000. 1,006,227 soil samples were analyzed and uploaded on Korean soil information system (http://soil.rda.go.kr) from 2003 to 2013. Soil pH has changed from 6.1 to 6.2. Organic matter (OM), available (Avail.) phosphate and exchangeable (Exch.) K have decreased from 24 to $23gkg^{-1}$, 541 to $399mgkg^{-1}$ and 0.90 to $0.72cmol_ckg^{-1}$ between 2003 and 2013, respectively. Especially, Exch. Ca contents decreased to $5.7cmol_ckg^{-1}$ in 2009 and increased to $6.2cmol_ckg^{-1}$ in 2013. Ratios of optimal ranges for cropping were 48% for pH, 22% for OM, 26% for Avail. phosphate, and 23, 16, 22% for Exch. K, Ca and Mg in 2013. Ratios of optimal ranges for pH increased and low ranges for OM, Avail. phosphate and Exch. K increased. Frequency distribution was 64% for pH 5.5~7.0, 65% for OM $10{\sim}30gkg^{-1}$, 48% for Avail. phosphate under $300mgkg^{-1}$ and 23, 29, 22% for Exch. K 0.2~0.6, Ca 4.0~6.0 and Mg $1.0{\sim}1.5cmol_ckg^{-1}$.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.33-33
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• 1992

항혈전성 약물로서 그의 항 혈소판 작용력은 dipyridamole보다 강하나 심혈관계 등에 대한 부작용이 적어 clinical efficiency가 유의하게 높은 약물개발에 대한 연구는 임상적 응용성 뿐 아니라, 혈소판-응고기전의 규명에 기여할 것으로 사료되는 바 본 연구에서는 cyclic nucleotide phosphodiesterase(PDE-I)들의 항혈소판 작용을 검토하여 그들의 혈관 내피세포와 혈관평활 근세포의 중식에 대한 영향을 항혈소판성 작용을 보이며 혈관세포들의 증식에 없어서는 안되는 spermine의 그것과 비교 검색하였다. Johnson 등(1985)의 방법에 따라서 제조한 aequorin부하-가토혈소판의 thrombin(0.25 units: TB)에 대한 응집반응에서, pyridazinone 유도체인 KR30075, sodium nitroprusside(SNP), imazodan, isobutylmethylxanthine(IBMX), rolipram, 및 spermine의 응집억제성 $IC_{50}$/ (M)은 각각 2.21 $\times$ $10^{-7}$, 1.26 $\times$ $10^{-6}$, 6.96 $\times$ $10^{-6}$, 7.78 $\times$ $10^{-6}$, 8.11 $\times$ $10^{-4}$, 및 4.28 $\times$ $10^{-3}$ M으로써 이들은 TB-응고반응에 동반되는 혈소판 [Ca$^{++}$]$_{i}$-증가에 대한 각각의 $IC_{50}$/과 차이를 보이지 않았으며, 유의한 상관성을 보였다.

• Korean Journal of Metals and Materials
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• v.50 no.5
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• pp.395-400
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• 2012

In this study, we have investigated the surface morphology of hydroxyapatite (HA) coated Ti alloy surface using pulsed laser plating. The HA (tooth ash) films were grown by pulsed KrF excimer laser, film surfaces were analyzed for topology, chemical composition, crystal structure and electrochemical behavior. The Ti-6Al-4V alloy showed ${\alpha}$ and ${\beta}$ phase, Cp-Ti showed ${\alpha}$ phase and the HA coated surface showed HA and Ti alloy peaks. The HA coating layer was formed with $1-2{\mu}m$ droplets and grain-like particles, particles which were smaller than the HA target particle, and the composition of the HA coatings were composed of Ca and P. From the electrochemical test, the pitting potential (1580 mV) of HA coated Ti-6Al-4V alloy was higher than those of Cp-Ti (1060 mV) and HA coated Cp-Ti (1350 mV). The HA coated samples showed a lower current density than non-HA coated samples, whereas, the polarization resistance of HA coated samples showed a high value compared to non-HA coated samples.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.331-340
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• 2022

Early afterdepolarization (EAD), a significant cause of fatal ventricular arrhythmias including Torsade de Pointes (TdP) in long QT syndromes, is a depolarizing afterpotential at the plateau or repolarization phase in action potential (AP) profile early before completing one pace. AP duration prolongation is related to EAD but is not necessarily accounted for EAD. Several computational studies suggested EAD can form from an abnormality in the late plateau and/or repolarization phase of AP shape. In this sense, we hypothesized the slope during repolarization has the characteristics to predict TdP risk, mainly focusing on the maximum slope during repolarization (dVm/dt_{max_repol}). This study aimed to predict the sensitivity of dVm/dt_{max_repol} to ion channel conductances as a TdP risk metric through a population simulation considering multiple effects of simultaneous reduction in six ion channel conductances of g_NaL, g_Kr, g_Ks, g_to, g_K1, and g_CaL. Additionally, we verified the availability of dVm/dt_{max_repol} for TdP risk prediction through the correlation analysis with qNet, the representative TdP metric. We performed the population simulations based on the methodology of Gemmel et al. using the human ventricular myocyte model of Dutta et al. Among the sixion channel conductances, dVm/dt_{max_repol} and qNet responded most sensitively to the change in g_Kr, followed by g_NaL. Furthermore, dVm/dt_{max_repol} showed a statistically significant high negative correlation with qNet. The dVm/dt_{max_repol} values were significantly different according to three TdP risk levels of high, intermediate, and low by qNet (p<0.001). In conclusion, we suggested dVm/dt_{max_repol} as a new biomarker metric for TdP risk assessment.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.46.1-46.1
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• 2018

The Fast Imaging Solar Spectrograph (FISS) on the Goode Solar Telescope (GST) at Big Bear Solar Observatory is the imaging Echelle spectrograph developed by the Solar Astronomy Group of Seoul National University and the Solar and Space Weather Group of Korea Astronomy and Space Science Institute. The instrument takes spectral data from a region on the Sun in two spectral bands simultaneously. The imaging is done by the organization of intensity data obtained from the fast raster scan of the slit over the field of view. Since the scan repeats many times, the whole set of data can be used to construct the movies of monochromatic intensity at arbitrary wavelengths within the spectral bands, and those of line-of-sight velocity inferred from different spectral lines. So far there are two standard observing configurations: one recording the $H{\alpha}$ line and the Ca II 8542 line simultaneously, and the other recording the Na I D2 line and Fe I 5435 line simultaneously. We have developed the procedures to produce the standard data for each observing configuration. The procedures include the spatial alignment, the correction of spectral shift of instrumental origin, and the lambdameter measurement of the line wavelength. The standard data include the movie of continuum intensity, the movies of intensity and velocity inferred from a chromospheric spectral line, the movies of intensity and velocity inferred from a photospheric line. The processed standard data will be freely available online (fiss.snu.ac.kr) to be used for research and public outreach. Moreover, the IDL procedures will be provided on request as well so that each researcher can adapt the programs for their own research.