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>

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.

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

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>

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

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).

사회배려대상을 위한 대학입학전형에 관한 연구 : 다문화가정 자녀를 중심으로

김빛나라(Kim, Bitnara),주철안(Joo, Chul-An) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.4

The purpose of this study was to grasp the current situation of university admissions for multicultural students and deduce implications. This study focused the admissions for multicultural students of the major 30 universities. Only 24 universities of them had an admissions for multicultural students and they recruted only 0.86% of the total population in university admissions for multicultural students. Departments that were not recruiting students were a lot. And most of the deparments of Medicine and Pharmacy were not included. Except 6 university, not only multicultural students but also another students with a social weak could apply the university admissions for multicultural students. So it was considered that the benefits for multicultural students would be less than intention. It is required the quantitative expansion and the qualitative improvement of the university admissions for multicultural students. Also the government and each university have to make an effort to achieve the purpose of the university admissions for multicultural students. Social efforts and support are needed continously after entering university to ensure that the multicultural students would be an authentic member of this society. 본 연구는 대학교육 기회 균등 실현의 측면에서 사회적 약자를 배려하기 위해 실시되고 있는 다문화가정 자녀 대상 대학입학전형의 운영 실제를 분석하고 그에 따른 정책적 시사점을 탐색하기 위해 수행되었다. 이를 위해 국내 주요 29개 대학의 입학전형을 중심으로 분석하였다. 29개 대학 중 23개 대학에서 다문화가정 자녀 대상 대학입학전형을 운영하고 있고, 모집인원은 29개 대학 전체 모집인원 대비 0.88%를 구성하고 있다. 모집학과는 의·약학계열 등 경쟁률 상위 학과를 대상으로 하지 않는 대학이 많았다. 29개 대학 중 6개 대학을 제외한 모든 대학에서는 다문화가정 자녀들이 지원할 수 있는 전형에 다른 사회배려대상도 함께 지원할 수 있도록 함으로써 다문화가정 자녀들의 실질적인 입학기회는 더욱 낮아지는 구조이었다. 본격적인 다문화사회로 진입한 우리 사회의 변화를 반영하여 다문화가정 대상 대학입학전형의 양적 확대와 질적 개선이 요구된다. 정부 차원에서는 정원 외 특별전형 대상에 다문화가정 자녀를 포함하는 방안을 고려해볼 수 있으며, 대학 차원에서는 사회배려대상 대학입학전형에 지원대상별로 모집인원을 할당하고 모집학과에 대한 검토와 개선이 필요하다. 나아가, 다문화가정 자녀가 대학 입학 과정에서의 평등뿐 아니라 대학 입학 이후의 적응, 그리고 사회의 책임 있는 구성원으로 성장할 수 있도록 제도적인 지원과 범사회적인 노력이 요구된다.

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.

Poly-γ-glutamic acid suppresses osteoclastogenesis in human osteoclast precursors and prevents joint damage in a collagen-induced murine arthritis model

Lee, Bitnara,Jo, Sungsin,Kim, Sung-Min,Cho, Mi-La,Park, Sung-Hwan,Youn, Jeehee,Ji, Jong Dae,Kim, Tae-Hwan Elsevier 2018 IMMUNOLOGY LETTERS Vol.203 No.-

<P><B>Abstract</B></P> <P>Poly–γ-glutamic acid (γ-PGA), a natural polymer derived from <I>Bacillus subtilis</I>, shows anti-inflammatory activity. However, the effects of γ-PGA on osteoclasts, which are important cells for joint destruction in inflammatory diseases such as rheumatoid arthritis (RA), have not yet been reported. In this study, we show that γ-PGA markedly inhibits osteoclast differentiation in normal PBMC-derived osteoclast precursors and in synovial fluid macrophages of patients with RA. γ-PGA also reduces RANK expression by down-regulating M-CSF receptors. Additionally, oral administration of γ-PGA attenuated bone destruction in a collagen-induced arthritis (CIA) model, demonstrating decreases in inflammation, cartilage damage, and osteoclast formation in histological analyses. Taken together, these data suggest that γ-PGA could be a good candidate for therapeutic prevention of joint destruction in RA.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Poly-γ-glutamic acid (γ-PGA) inhibited osteoclast differentiation in normal PBMC-derived osteoclast precursors and RA synovial fluid macrophages. </LI> <LI> Treatment with γ-PGA suppressed osteoclastogenesis <I>in vitro</I> and <I>in vivo</I>. </LI> <LI> Oral administration of γ-PGA markedly reduced bone destruction in collagen-induced mouse (CIA) model. </LI> </UL> </P>