AN ANALYSIS ON THE SENSITIVITY OF MT DATA TO GEOTHERMAL RESERVOIRS CONSIDERING ELECTRICAL ANISOTROPY

Bitnarae KIM,Myung Jin NAM 한국신재생에너지학회 2015 AFORE Vol.2015 No.11

Analysis on Monitoring Ground Subsidence near Excavation Region Based on Synthetic Model Tests

( Bitnarae Kim ),( A Hyun Cho ),( Myung Jin Nam ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Geophysical methods have become promising approaches in civil and environmental engineering, and adopted in a wide range of applications like investigations ground for building construction, inspection of dams and dikes, etc. Especially, in the case of building construction, geophysical surveys can provide with not only useful information on subsurface structure but also with monitoring early dangerous regions near the construction site. Ground subsidence near excavation region can cause serious damages on construction field including human, and thus it is important to monitor weather or not excavation loosens nearby ground in construction field. For this purpose, electrical resistivity (DC) methods among many geophysical methods can be the best choice, since DC survey can monitor changes electrical resistivity of subsurface that can be further interpreted subsurface structure. Using our previously developed 3-dimensional DC resistivity inversion algorithm considering excavation, this study will perform numerical analysis on the effectiveness of the developed method in monitoring ground near excavation; we simulate and invert time-lapse DC responses for various numerical models with soft ground and/or ground subsidence. Further, sensitivity analysis on DC surveys near excavation region are made to determine appropriate DC array geometries for monitoring ground near excavation. This study was supported by KAIA under MOLIT (No. 15SCIP-B108153-01) and by KEITI under ME (No. 2018002440005).

Hepatoprotective constituents of <i>Firmiana simplex</i> stem bark against ethanol insult to primary rat hepatocytes

Kim, Jung Wha,Yang, Heejung,Cho, Namki,Kim, Bitnarae,Kim, Young Choong,Sung, Sang Hyun Medknow PublicationsMedia Pvt Ltd 2015 Pharmacognosy magazine Vol.11 No.41

<P><B>Background:</B></P><P>Ethanol causes hepatic cellular damage by alterations in biological functions. This study evaluated the hepatoprotective potential of the methanolic extract originating from <I>Firmiana simplex</I> (Sterculiaceae) stem bark against the ethanol-induced hepatotoxicity in rat primary hepatocytes.</P><P><B>Materials and Methods:</B></P><P>The extract of <I>F. simplex</I> stem bark was successively fractionated into <I>n</I>-hexane, chloroform, ethyl acetate (EtOAc), and <I>n</I>-butanol. Column chromatography with silica gel and sephadex LH-20 was used to isolate the EtOAc fraction. Rat primary hepatocytes were cultured to study the hepatoprotective activity of isolated substances against ethanol-induced toxicity. Intracellular reactive oxygen species (ROS) levels, the antioxidant activities of glutathione reductase (GR) and glutathione peroxidase (GSH-P<SUB>X</SUB>) enzymes, and the GSH content were measured to examine the antioxidative property of the isolated compounds.</P><P><B>Results:</B></P><P>Two flavonoid glycosides, quercitrin (1) and tamarixetin 3-O-rhamnopyranoside (2), were isolated from the active EtOAc fraction. Compound 1 significantly protected rat primary hepatocytes against ethanol-induced oxidative stress by reducing the intracellular ROS level and preserving antioxidative defense systems such as GR, GSH-P<SUB>X</SUB>, and total GSH.</P><P><B>Conclusion:</B></P><P>This is the first report on the hepatoprotective activities of the extract of <I>F. simplex</I>. The EtOAc fraction of <I>F. simplex</I> stem bark and its major constituent quercitrin (1) could function as hepatoprotective agents to attenuate the development of alcoholic liver disease.</P>

수직 횡등방성 전기적 이방성을 고려한 자기지전류탐사 모델링

김빛나래 ( Bitnarae Kim ),남명진 ( Myung Jin Nam ) 한국지구물리·물리탐사학회 2015 지구물리와 물리탐사 Vol.18 No.4

자연 전자기장을 이용하여 지하 매질의 전기적 구조를 규명하는 자기지전류(magnetotelluric; MT) 탐사의 정확한해석을 위해서는 특정 전기적 구조에 대한 정확한 수치적 반응을 구할 수 있는 3차원 모델링이 필수적이다. 특히, 매질내에 전기적 이방성이 있을 때는 MT 반응이 달라지므로 전기적 이방성의 영향을 고려한 MT 탐사 모델링이 필요하다. 특히, MT 탐사기법을 이용한 지열저류층의 모니터링과 같이 MT 반응의 작은 변화를 분석해야 하는 시간경과 자료의 해석의 경우, 대상 지역에 이방성이 존재할 경우 이를 고려할 수 있는 정확한 모델링이 필수적이다. 이 연구에서는 기존의 등방성만을 고려하던 유한차분법 MT 모델링 알고리듬을 수직 혹은 수평 횡등방성 이방성을 고려할 수 있도록 개선하였다. 개발한 알고리듬을 박리층 모델을 이용하여 검증한 후, 수직횡등방성 이방성이 MT 반응에 미치는 영향에 대해서 분석하였다. 향후에는 수평 횡등방성 이방성이 MT 반응에 미치는 영향에 대해서도 분석하고자 하며, 알고리듬을 더욱 발전시켜 경사 횡등방성 이방성까지 고려할 수 있도록 발전시키고자 한다. Magnetotelluric (MT) survey investigates electrical structure of subsurface by measuring natural electromagnetic fields on the earth surface. For the accurate interpretation of MT data, the precise three-dimensional (3-D) modeling algorithm is prerequisite. Since MT responses are affected by electrical anisotropy of medium, the modeling algorithm has to incorporate the electrical anisotropy especially when analyzing time-lapse MT data sets, for monitoring engineered geothermal system (EGS) reservoir, because changes in different-vintage MT-data sets are small. This study developed a MT modeling algorithm for the simulation MT responses in the presence of electrical anisotropy by improving a preexisting staggered-grid finite-difference MT modeling algorithm. After verifying the developed algorithm, we analyzed the effect of vertical transversely isotropic (VTI) anisotropy on MT responses. In addition, we are planning to extend the applicability of the developed algorithm which can simulate not only the horizontal transversely isotropic (HTI) anisotropy, but also the tiled transversely isotropic (TTI) anisotropy.

유도분극 탐사의 원리 및 활용

김빛나래 ( Bitnarae Kim ),남명진 ( Myung Jin Nam ),장한누리 ( Hannuree Jang ),장한길로 ( Hangilro Jang ),손정술 ( Jeong-sul Son ),김희준 ( Hee Jun Kim ) 한국지구물리·물리탐사학회 2017 지구물리와 물리탐사 Vol.20 No.2

유도분극(induced polarization; IP) 탐사는 분극 현상으로 인해 매질에서 발생하는 과전압을 측정하는 전기전자탐사법으로 주로 금속 광상을 찾을 때 사용되었으나 장비의 발전에 힘입어 최근에는 지하수, 환경 오염, 지반 등 여러 분야에서 다양하게 활용되고 있다. IP 탐사에는 충전율을 측정하는 시간영역 IP 탐사, 진동수 효과를 측정하는 진동수영역IP 탐사, 그리고 복소수 전기비저항을 측정하는 복소 전기비저항 탐사와 광대역 IP (spectral IP; SIP) 탐사 등이 있다. 또한, 최근에는 전극 형태의 측정 방법의 단점을 보완하기 위해 전자기 유도에 기초한 IP 법도 개발되어 지속적으로 연구가 진행되고 있다. 다양한 IP 탐사법에 대한 체계적인 이해를 돕기 위해 이 논문에서는 1) 송신원 형태와 측정 자료를 기준으로 IP 탐사법을 분류하고 이들에 대한 개념 정리와 함께 2) 각 탐사법의 수치 모델링 및 역산 알고리듬 발전 과정을 자세히 기술하고 3) 마지막으로 IP 탐사의 다양한 현장 활용 사례를 소개하고자 한다. Induced polarization (IP) method is based on the measurement of a polarization effect known as overvoltage of the ground. IP techniques have been usually used to find mineral deposits, however, nowadays widely applied to hydrogeological investigations, surveys of groundwater pollution and foundation studies on construction sites. IP surveys can be classified by its source type, i.e., time-domain IP estimating chargeability, frequency-domain IP measuring frequency effect (FE), and complex resistivity (CR) and spectral IP (SIP) measuring complex resistivity. Recently, electromagnetic-based IP has been studied to avoid the requirement for spike electrodes to be placed in the ground. In order to understand IP methods in this study, we: 1) classify IP surveys by source type and measured data and illustrate their basic theories, 2) describe historical development of each IP forward modeling and inversion algorithm, and finally 3) introduce various case studies of IP measurements.

Efficient method for generating homozygous embryonic stem cells in mice

Bitnara Kim,Seongjun So,Jiwan Choi,Eunju Kang,Yeonmi Lee 한국동물생명공학회(구 한국동물번식학회) 2022 Journal of Animal Reproduction and Biotechnology Vol.37 No.1

Parthenogenesis is maternally uniparental reproduction through the embryonic development of oocytes without fertilization. Artificial activation of mature oocytes could generate homozygous haploid embryos with the extrusion of the second polar body. However, the haploid embryos showed low embryo development in preimplantation embryos. In this study, we investigated whether the electronic fusion of the haploid embryos could enhance embryo development and ESC establishment in mice. Haploid embryos showed the developmental delay from 4-cell to the blastocyst stage. The haploid blastomeres of the 2-cell stage were fused electronically, resulting in that the fused embryos showed a significantly higher rate of blastocysts compared to non-fused haploid embryos (55% vs. 37%). Further, the embryonic stem cells (ESCs) derived from the fused embryos were confirmed to be diploid. The rate of ESC establishment in fused embryos was significantly higher compared to non-fused ones. Based on the results, we concluded that the electronic fusion of haploid embryos could be efficient to generate homozygous ESCs.

T-cell responses to versican in ankylosing spondylitis

Kim, Tae-Jong,Kim, Tae-Hwan,Lee, Hyun-Joo,Lee, Bitnara,Robin Poole, A.,Inman, Robert D. Springer-Verlag 2011 Rheumatology International Vol.31 No.2

Efficient method for generating homozygous embryonic stem cells in mice

Bitnara Kim,Seongjun So,Jiwan Choi,Eunju Kang,Yeonmi Lee 한국동물생명공학회(구 한국수정란이식학회) 2022 한국동물생명공학회지 Vol.37 No.1

Parthenogenesis is maternally uniparental reproduction through the embryonic development of oocytes without fertilization. Artificial activation of mature oocytes could generate homozygous haploid embryos with the extrusion of the second polar body. However, the haploid embryos showed low embryo development in preimplantation embryos. In this study, we investigated whether the electronic fusion of the haploid embryos could enhance embryo development and ESC establishment in mice. Haploid embryos showed the developmental delay from 4-cell to the blastocyst stage. The haploid blastomeres of the 2-cell stage were fused electronically, resulting in that the fused embryos showed a significantly higher rate of blastocysts compared to non-fused haploid embryos (55% vs. 37%). Further, the embryonic stem cells (ESCs) derived from the fused embryos were confirmed to be diploid. The rate of ESC establishment in fused embryos was significantly higher compared to non-fused ones. Based on the results, we concluded that the electronic fusion of haploid embryos could be efficient to generate homozygous ESCs.

Ionic strength effect on molecular structure of hyaluronic acid investigated by flow field-flow fractionation and multiangle light scattering.

Kim, Bitnara,Woo, Sohee,Park, Young-Soo,Hwang, Euijin,Moon, Myeong Hee Springer-Verlag 2015 Analytical and Bioanalytical Chemistry Vol.407 No.5

<P>This study describes the effect of ionic strength on the molecular structure of hyaluronic acid (HA) in an aqueous solution using flow field-flow fractionation and multiangle light scattering (FlFFF-MALS). Sodium salts of HA (NaHA) raw materials (???2????????10(6) Da) dispersed in different concentrations of NaCl prepared by repeated dilution/ultrafiltration procedures were examined in order to study conformational changes in terms of the relationship between the radius of gyration and molecular weight (MW) and molecular weight distribution (MWD) of NaHA in solution. This was achieved by varying the ionic strength of the carrier solution used in a frit-inlet asymmetrical FlFFF (FIAF4) channel. Experiments showed that the average MW of NaHA increased as the ionic strength of the NaHA solution decreased due to enhanced entanglement or aggregation of HA molecules. Relatively large molecules (greater than ???5??MDa) did not show a large increase in RMS radius value as the NaCl concentration decreased. Conversely, smaller species showed larger changes, suggesting molecular expansion at lower ionic strengths. When the ionic strength of the FlFFF carrier solution was decreased, the HA species in a salt-rich solution (0.2??M NaCl) underwent rapid molecular aggregation during FlFFF separation. However, when salt-depleted HA samples (I???=???4.66???0.38??mM) were analyzed with FFF carrier solutions of a high ionic strength, the changes in both molecular structure and size were somewhat reversible, although there was a delay in correction of the molecular structure.</P>

A dual role of TGF-β in human osteoclast differentiation mediated by Smad1 versus Smad3 signaling

Lee, Bitnara,Oh, Younseo,Jo, Sungsin,Kim, Tae-Hwan,Ji, Jong Dae Elsevier Science 2019 IMMUNOLOGY LETTERS Vol.206 No.-

<P><B>Abstract</B></P> <P>TGF-β1 is highly expressed in the synovial tissue of patients with rheumatoid arthritis and is known as a cytokine that plays an important role in tissue repair and immune cell regulation. However, the role of TGF-β1 is still unclear in osteoclastogenesis. In this study, we examined the effect of TGF-β1 on osteoclast differentiation and the underlying mechanism using healthy human peripheral blood monocytes. TGF-β1 was found to inhibit osteoclast differentiation and decrease the expression of osteoclast-specific genes such as acid phosphatase 5, tartrate resistant and cathepsin K. Levels of NFAT1, an important transcription factor in osteoclastogenesis, were also reduced. In addition, TGF-β1 suppressed receptor activator of NF-κB (RANK) ligand-induced NF-κB and p38 MAPK signaling. Inhibition of osteoclast differentiation by TGF-β1 was reversed by 1 μM SB431542 (an inhibitor of ALK4/5/7), which inhibited TGF-β1-induced phosphorylation of SMAD1, but not that of SMAD3. TGF-β1 also restricted RANK expression, and this was partially reversed by 1 μM SB431542. In contrast, the inhibition of SMAD3 by SIS3 (an inhibitor of SMAD3) reduced the osteoclast formation. TGF-β1 has both inhibitory and stimulatory effects on human osteoclast differentiation, and that these opposing functions are mediated by SMAD1 and SMAD3 signaling, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> TGF-β has both inhibitory and stimulatory effects on human osteoclast differentiation. </LI> <LI> These inhibitory and stimulatory effects on human osteoclast are mediated by SMAD1 and SMAD3 signaling, respectively. </LI> <LI> SMAD1 and SMAD3 exert different regulatory effects on important osteoclast-related genes such as TNFRSF11 A (encoding RANK) and MMP9. </LI> </UL> </P>