Anti-proliferative effect of <i>Zea mays</i> L. cob extract on rat C6 glioma cells through regulation of glycolysis, mitochondrial ROS, and apoptosis

Hwang, Eunmi,Sim, Sangwan,Park, Sang Hyuk,Song, Ki Duk,Lee, Hak-Kyo,Heo, Tae-Hwe,Jun, Hyun Sik,Kim, Sung-Jo Elsevier 2018 BIOMEDICINE AND PHARMACOTHERAPY Vol.98 No.-

<P><B>Abstract</B></P> <P>Gliomas are one of the most common types of primary brain tumors, characterized by rapid proliferation and infiltration into normal brain tissue. Corncob is the most plentiful byproducts of <I>Zea mays</I> L., of which anti-cancer effect has not been reported. Therefore, we aimed to examine the anti-proliferative effect of a high-pressure hot-water extract of corncob on glioma cells and elucidated the underlying mechanism. The high-pressure hot-water corncob extract contained approximately 94.8 mg/g and 1.82 μg/g of total phenol and catechin, respectively. Glioma cell treated with different concentrations of high-pressure hot-water corncob extract was shown to be suppressed in growth during three days of culture. In parallel, corncob extract reduced the glioma cell viability and induced cell cycle arrest in G0/G1 phase by upregulating the expression level of cyclin-dependent kinase inhibitor p21. Decreased proliferation and viability in glioma cells treated with corncob extract can be attributed to reduced reactive oxygen species (ROS), antiapoptotic Bcl-2 protein, and a lactate transporter monocarboxylate transporter 1 of which levels are higher than those in normal cells. Based on its inhibitory effects on proliferation and viability of C6 glioma cells, a high-pressure hot-water corncob extract has the potential to be used for glioma treatment.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Assessment Practices in Primary English Programs

Eunmi Hwang 한국초등영어교육학회 2006 초등영어교육 Vol.12 No.2

  The purpose of this study was to explore language assessment practices in primary English as a foreign language (EFL) programs in Korea through the voices of teachers and the eyes of a researcher. The study incorporated teacher interviews, classroom observations, and a collection of assessment materials in three different primary English programs (a public school, a private school, and a private after-school language institute) in Seoul, Korea. Various types of assessment tools including performance assessment (e.g., role-plays, information gaps, observation checklists) and other alternatives (e.g., self-assessment) were found to be the most commonly used in the three institutions. Although traditional paper-pencil tests were used as well, its use seemed very limited. The choice of assessment tools seemed to be affected by English educational goals and class size in each institution.

The Effect of Caregivers" Active Participation with Education in Peripheral Intravenous Injections for Their Child

Eunmi Hwang,Dongsuk Lee 한국간호과학회 2015 한국간호과학회 학술대회 Vol.2015 No.10

Suppression of the Toll-like receptors 3 mediated pro-inflammatory gene expressions by progenitor cell differentiation and proliferation factor in chicken DF-1 cells

( Eunmi Hwang ),( Hyungkuen Kim ),( Anh Duc Truong ),( Sung-jo Kim ),( Ki-duk Song ) 한국축산학회 2022 한국축산학회지 Vol.64 No.1

Toll-like receptors (TLRs), as a part of innate immunity, plays an important role in detecting pathogenic molecular patterns (PAMPs) which are structural components or product of pathogens and initiate host defense systems or innate immunity. Precise negative feedback regulations of TLR signaling are important in maintaining homeostasis to prevent tissue damage by uncontrolled inflammation during innate immune responses. In this study, we identified and characterized the function of the pancreatic progenitor cell differentiation and proliferation factor (PPDPF) as a negative regulator for TLR signal-mediated inflammation in chicken. Bioinformatics analysis showed that the structure of chicken PPDPF evolutionarily conserved amino acid sequences with domains, i.e., SH3 binding sites and CDC-like kinase 2 (CLK2) binding sites, suggesting that relevant signaling pathways might contribute to suppression of inflammation. Our results showed that stimulation with polyinosinic:polycytidylic acids (Poly [I:C]), a synthetic agonist for TLR3 signaling, increased the mRNA expression of PPDPF in chicken fibroblasts DF-1 but not in chicken macrophage-like cells HD11. In addition, the expression of pro-inflammatory genes stimulated by Poly(I:C) were reduced in DF-1 cells which overexpress PPDPF. Future studies warrant to reveal the molecular mechanisms responsible for the anti-inflammatory capacity of PPDPF in chicken as well as a potential target for controlling viral resistance.

New liquid carbon dioxide based strategy for high energy/power density LiFePO₄

Hwang, Jieun,Kong, Ki Chun,Chang, Wonyoung,Jo, Eunmi,Nam, Kyungwan,Kim, Jaehoon unknown 2017 Nano energy Vol.36 No.-

<P><B>Abstract</B></P> <P>A liquid carbon dioxide (<I>l</I>-CO<SUB>2</SUB>) based coating approach is developed for ultrathin, uniform, and conformal carbon coating of hierarchically mesoporous LiFePO<SUB>4</SUB> (LFP) nano/microspheres for fabricating high-energy-density and high-power-density carbon coated LFP (C-LFP) with long-term cyclability. The unique properties of <I>l</I>-CO<SUB>2</SUB> result in an ultrathin carbon layer (1.9nm) distributed all over the primary nano-sized LFP particles (20–140nm in diameter), forming a core (LFP)-shell (carbon) structure. This unique structure provides facile penetration of liquid electrolytes and rapid electron and Li-ion transport. C-LFP exhibits high reversible capacity, high energy and power density (168mAhg<SUP>−1</SUP> at 0.1C, 109Whkg<SUP>−1</SUP> and 3.3kWkg<SUP>−1</SUP> at 30C, respectively) with excellent long-term cyclability (84% cycle retention at 10C after 1000 cycles). In addition, the ultrathin and uniform carbon layer of the mesoporous microspheres allows a high tap density (1.4gcm<SUP>−3</SUP>) resulting in a high volumetric energy density (458WhL<SUP>−1</SUP> at a 30C rate). Furthermore, C-LFP presents a high capacity and stable cycling performance under low-temperature and high-temperature environment. Well-developed carbon coating approach in this study is simple, scalable, and environmentally benign, making it very promising for commercial-scale production of electrode materials for large-scale Li-ion battery applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Uniform and ultrathin carbon layer coating on LFP particles using liquid CO<SUB>2</SUB>. </LI> <LI> Uniform carbon distribution on hierarchical porous nano/micron LFP. </LI> <LI> High energy densities (109Whkg<SUP>−1</SUP>, 458WhL<SUP>−1</SUP>) at 30C achieved. </LI> <LI> High power densities (3.3kWkg<SUP>−1</SUP> at 30C) and long-term cyclability achieved. </LI> <LI> Excellent cycling tolerance under challenging conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Investigation of Thermal Stability of P2–Na_<i>x</i>CoO₂ Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy

Hwang, Sooyeon,Lee, Yongho,Jo, Eunmi,Chung, Kyung Yoon,Choi, Wonchang,Kim, Seung Min,Chang, Wonyoung American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.22

<P>Here, we take advantage of in situ transmission electron microscopy (TEM) to investigate the thermal stability of P2-type NaxCoO2 cathode materials for sodium ion batteries, which are promising candidates for next-generation lithium ion batteries. A double-tilt TEM heating holder was used to directly characterize the changes in the morphology and the crystallographic and electronic structures of the materials with increase in temperature. The electron diffraction, patterns and the electron energy loss spectra demonstrated the presence of cobalt oxides (Co3O4), CoO) and even metallic cobalt,(Co) at higher temperatures as a result of reduction of Co ions and loss of oxygen. The bright-field TEM images revealed that the surface of NaxCoO2, becomes porous at high temperatures. Higher, cutoff voltages result in degrading thermal stability of NaxCoO2. The observations herein provide a valuable insight that thermal stability is one of the important factors to be considered in addition to the electrochemical properties when developing, new electrode materials for novel battery systems.</P>

Injectable gelatin-poly(ethylene glycol) adhesive hydrogels with highly hemostatic and wound healing capabilities

Jinyoung Hwang,Phuong Le Thi,이시민,Eun-Hye Park,Eunmi Lee,Eunmin Kim,장기육,박기동 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Although numerous poly(ethylene glycol) (PEG)-based bioadhesives have been developed and commercializedfor various biomedical applications, their biocompatibility and bioactivity performances are generallylacking. In addition, the development of adhesive hydrogels with rapid gelation and high tissueadhesion are desirable to promote the surgical procedures and enhance patient compliance. To overcomethese problems, we designed a series of chemically crosslinked gelatin-PEG adhesive hydrogels (GP)through the enzymatic crosslinking reaction of horseradish peroxidase (HRP). The resultant GP hydrogelswere rapidly formed in situ within seconds to minutes after injection, and their mechanical as well asadhesive properties were adjustable in a wide range by changing the molecular weight and content ofPEG. Notably, the hybrid hydrogels composed of 20 kDa PEG with ratio of 2.5/7.5 gelatin/PEG (wt/wt)showed 11 times greater tissue adhesiveness than commercially available fibrin glues. From in vitro cellstudies, the hybrid adhesive hydrogels are nontoxic and improve the cell proliferation. Importantly, thehydrogels exhibited excellent hemostatic capability and accelerated the wound healing in vivo, comparedto fibrin glue. These injectable GP hydrogels effectively improved the tissue adhesiveness and bioactivityof PEG-based adhesives, and hold great potential for hemostatic and wound healing treatments.

실시간 강수량을 고려한 도로 침수위험지수 개발 방법에 대한 연구

김은미(Eunmi Kim),황현숙(Hyun Suk Hwang),김창수(Chang Soo Kim) 한국멀티미디어학회 2013 멀티미디어학회논문지 Vol.16 No.5

Development of hybrid system with fuel cell and lithium secondary battery

황상문(Hwang, Sangmoon),정은미(Jung, Eunmi),손동언(Son, Dongun),심태희(Shim, Taehee),송하영(Song, Hayoung) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

Therefore, with this development assignment we'd like to develop the hybrid system combining 800W DMFC (Direct Methanol Fuel Cell) and 1.6kW of Lithium secondary battery pack which can be applied to the most common small cart. a scooter, to secure the development capability of hundreds of Watts DMFC, the high-capacity Lithium secondary battery pack, the technology of BMS (Battery Management System) and the development technology of hybrid system. DMFC, in fact, has lower energy efficiency than PEMFC (Polymer Electrolyte Membrane Fuel Cell); however, it has several advantages in terms of fuel storage and use. It is pretty easy to be stored and used without any additional colling and heating devices because of its insensitive liquid methanol to temperature. In conclusion, DMFC system is the most suitable device for small mobile vehicles.

재한 중국인 유학생의 대학생활스트레스와 대학생활적응의 관계

박은미(Eunmi Park),황빙의(Bingyi Hwang),정태연(Taeyun Jung) 대한스트레스학회 2010 스트레스硏究 Vol.18 No.2

본 연구는 한국사회 내 지속적으로 증가하고 있는 중국인 유학생의 대학생활스트레스와 대학생활적응 간 관계에서 의사소통의 어려움, 한국생활의 어려움, 한국문화수용의 중재효과를 살펴보았다. 또한 중국인 유학생이 경험한 대학생활스트레스와 한국인 대학생이 평가하는 중국인 유학생의 대학생활스트레스 간 차이를 알아보고자 하였다. 이를 위해 서울시내 대학에 재학 중인 100명의 중국인 유학생과 98명의 한국인 대학생이 설문에 참여하였다. 분석 결과, 대학생활스트레스와 대학생활적응수준은 부적상관이 있었고, 의사소통의 어려움, 한국생활의 어려움, 한국문화수용 인식 가운데 한국생활의 어려움만 중재효과가 나타났다. 한국문화수용은 대학생활스트레스와 독립적으로 대학생활적응에 긍정적인 영향을 미쳤다. 한편, 중국인 유학생이 경험하는 대학생활스트레스의 정도에 대하여 중국인 유학생 당사자들보다 한국인 학생들이 더 높게 평가했다. 그러나 학업스트레스의 경우, 한국인 학생들이 평가하는 것보다 중국인 유학생이 경험하는 학업스트레스가 더 높았다. 이러한 결과를 토대로 중국인 유학생의 성공적인 대학생활적응을 위한 환경적 개선과 함의를 논의하였다. The study aimed to examine the moderating effect of Communicative Difficulties, Life Difficulties in Korea, and Adaptation to Korean Culture between School Adjustment and Stress, and to test difference of estimating College Life Stress of Chinese international undergraduates (CIUs) between Chinese and Korean. CIUs (n=100) and Korean undergraduates (n=98) attending a university in Seoul participated in the questionnaire study. Results indicated that School Adjustment was explained negatively by College Life Stress, and positively by Adaptation to Korean culture. Also, Life Difficulties in Korea of CIUs played a moderating role between School Adjustment and College Life Stress. The difference of estimating CIUs" college life stress between Chinese and Korean was as follows: The Korean undergraduates perceived CIUs feeling higher College Life Stress than those who actually experienced it. Despite Korean"s perceiving it, CIUs realized higher Study Stress. Finally, the findings were discussed in relation to relevant theories and research, and their implications for college life adjustment and limitations of the present study were suggested.