Surface modification of ethylene-vinyl alcohol copolymer treated with plasma source ion implantation

Hong, Seung In,Kim, Ki Beom,Lee, Yeonhee,Cho, Seung Yong,Ko, Jung A,Hong, Soon Kang,Park, Hyun Jin Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.113 No.5

<P>The plasma source ion implantation technique was applied to modify the surface of ethylene-vinyl alcohol (EVOH) film using various working gases. The effects of the treated films were observed on the adhesion efficiency and physical properties. The hydrophobic properties of EVOH films were greatly enhanced after tetrafluoromethane-plasma source ion implantation (PSII) treatment. On the other hand, the higher hydrophilic properties of EVOH films increased after oxygen-PSII treatment. The results of X-ray photoelectron spectroscopy showed that the improved hydrophobic or hydrophilic properties of the film were closely related to the formation of fluorine-containing functional groups (i.e., CF, CF<SUB>2</SUB>, and CF<SUB>3</SUB>) or oxygen-containing functional groups (i.e., C&n.bond;O, C&n.dbond;O) on the modified surface. According to the result observed by atomic force microscopy, the surface roughness was not influenced on the change of contact angle. Both the peel strength and oxygen barrier property were improved in the case of CF<SUB>4</SUB>+O<SUB>2</SUB>-PSII-treated EVOH films. As a function of aging time, the properties of modified EVOH surfaces were maintained after PSII treatment using CF<SUB>4</SUB> and O<SUB>2</SUB> at the energy level of −5 kV for 1 min. When using PSII treatment, the properties of the EVOH surface were controlled by working gas and treatment conditions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>

The anti-angiogenic herbal extracts Ob-X from <i>Morus alba</i>, <i>Melissa officinalis</i>, and <i>Artemisia capillaris</i> suppresses adipogenesis in 3T3-L1 adipocytes

Hong, Yeonhee,Kim, Min-Young,Yoon, Michung Informa Healthcare 2011 Pharmaceutical biology Vol.49 No.8

<P><I>Context</I>: Growing adipose tissue is thought to require adipogenesis, angiogenesis, and extracellular matrix (ECM) remodeling. Close examination of developing adipose tissue microvasculature reveals that angiogenesis often precedes adipogenesis. Since our previous study demonstrated that Ob-X, the anti-angiogenic herbal composition composed of <I>Melissa officinalis L</I>. (Labiatae), <I>Morus alba L</I>. (Moraceae), and <I>Artemisia capillaris Thunb</I>. (Compositae), reduced adipose tissue mass in obese mice, we hypothesized that adipogenesis can be inhibited by Ob-X.</P><P><I>Objective</I>: To investigate the effects of the anti-angiogenic herbal extracts Ob-X on adipogenesis in 3T3-L1 adipocytes.</P><P><I>Materials and methods</I>: After differentiated 3T3-L1 adipocytes were treated with Ob-X, we studied the effects of Ob-X on triglyceride accumulation and expression of genes involved in adipogenesis, angiogenesis, and ECM remodeling.</P><P><I>Results</I>: Treatment of cells with Ob-X inhibited lipid accumulation and adipocyte-specific gene expression caused by troglitazone or monocyte differentiation-inducing (MDI) mix. Ob-X reduced mRNA levels of angiogenic factors (vascular endothelial growth factor-A, -B, -C, -D, and fibroblast growth factor-2) and matrix metalloproteinases (MMPs; MMP-2 and MMP-9), whereas it increased mRNA levels of angiogenic inhibitors [(thrombospondin-1, tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-2)] in differentiated cells. MMP-2 and MMP-9 activities were also decreased in Ob-X-treated cells.</P><P><I>Discussion and conclusion</I>: These results suggest that the anti-angiogenic herbal composition Ob-X inhibits differentiation of preadipocytes into adipocytes. These events may be mediated by changes in the expression of genes involved in lipogenesis, angiogenesis, and the MMP system. Thus, by reducing adipogenesis, anti-angiogenic Ob-X provides a possible therapeutic approach for the prevention and treatment of human obesity and its related disorders.</P>

한강에서 분리된 Extended Spectrum β-Lactamase (ESBL) 대장균의 내성 연구

홍현진,천정녀,이연희 서울여자대학교 자연과학연구소 2003 자연과학연구논문집 Vol.15 No.-

Compared to the number of study with extended spectrum ,β-lactamases (ESBLs)producing clinical isolates, environmental ESBL-producers have not been extensively studied. To investigate environmental ESBL-producing Escherichia coli, twenty-two cephalothin-resistant E.coli were isolated from Han-river in Seoul, Korea. These isolates were resistant to ampicillin, cephalothin, and gentamicin and fourteen isolates among these were resistant to norfloxacin, too. All of these isolates produce AmpC and CMY, OXA, or TEM as determined by isoelectric point focusing gel electrophoresis and PCR. One isolate (No. 57-214) producing AmpC and OXA was resistant to all antibiotics (ampicillin, cephalothin, norfloxacin, gentamycin, cefotaxime, ceftazidime) tested in this study. Six isolates including isolate No. 57-214 could adhere to T24 human bladder cells and these isolates were not related to each other as shown with RAPD. ESBL을 생산하는 임상 균주에 대한 연구는 많은 연구가 진행되고 있는 데 비해 환경 균주에 대한 연구는 널리 진행되고 있지 않다. 환경에서 분리한 ESBL을 생산하는 E.coli를 연구하기 위해 서울의 한강에서 22개의 cephalothin 내성 E.coli를 분리하였다. 한강에서 분리한 22균주 모두 ampicillin, cephalothothin 그리고 gentamicin에 내성이었고, 이중 14 균주가 norfloxacin 에 내성이었다. PCR을 통하여 모든 균주가 AmpC와 CMY, OXA 또는 TEM을 가지고 있음을 확인하였고, 이들의 pI는 isoelectricfocusing을 통해 측정하였다. 특히, AmpC와 OXA를 생산하는 No.57-214는 본 실험에 사용한 모든 항생제에 내성을 보였다 (ampicillin, cephalothin, norfloxacin). 이들 균주들은 randomly amplified polymorphic DNA (RAPD) 를 이용하여 연관도를 분석한 결과 각각 모두 다른 균주임을 확인하였다.

임상에서 분리된 Escherichia coli, Pseudomonas aeruginosa, and MRSA 퀴놀론 내성균주

홍선의,이연희 서울여자대학교 자연과학연구소 1997 자연과학연구논문집 Vol.8 No.-

In this study, we screened 38 isolates of Escherichia coli, 99 isolates of Pseudomonas aeruginosa, and 106 isolates of methicillin resistant Staphylococcus aureus which were nocomial pathogens and clinically isolated in Yeonsei Severance Hospital in Korea for their susceptiblity to three quinolones. Among these, 92.1% of E. coli, 65.7% of P. aeruginosa, and 94.3% of MRSA showed resistance to all thredd quinolones. These numbers are extremely high and it is very urgent to treat these resistant bacteria.

2006년 돼지에서 분리한 대장균의 내성 현황

홍현진,이민영,이연희 서울여자대학교 자연과학연구소 2006 자연과학연구논문집 Vol.18 No.-

현재 축산 농가에서의 항생제의 오ㆍ남용은 매우 심각한 수준이다. 사료 배합용이나 성장 촉진제, 질병 예방용 등 수의사의 처방 없이 항생제를 사용하는 예가 많아짐에 따라 항생제 내성균도 점차 증가하고 있다. 그러므로 정확한 항생제의 판매량 파악과 내성 세균에 대한 모니터링이 매우 시급한 실정이다. 이에 본 연구에서는 돼지로부터 분리된 대장균을 대상으로 NCCLS 기준에 따라 항생제 최소억제농도를 측정하여 내성세균의 분포양상을 조사하였다. 이들 중 93.6%가 테트라사이클린에 대하여 내성을 나타내었으며, 61.1%가 클로람페니콜에 내성을 나타내었고, 64.8%가 암피실린에 내성을 나타내었다. 그리고 이들 중 33.2%가 4가지 이상의 항생제에 내성을 나타내는 다제내성 균주였다. 이에 축산농가에서 사용하고 있는 항생제에 대한 정확한 조사와 내성세균의 증가와 확산에 대한 지속적인 감시와 대책 마련이 요구된다. Overuse of antimicrobial agents in cattle farms, for treatment of infection as well as for prophylaxis and growth promotion has increased the occurrence of antimicrobial resistant bacteria. In this study, a total of 560 isolates of Eschenchia coli from pigs were isolated. Resistance of these isolates for 13 antimicrobial agents was determined by agar dilution method. Resistance rates to ampicillin, chloramphenicol, and tetracycline were 64.8%, 61.1%, and 93.6%, respectively. Mutiple drug resistance rate was 33.2%.

3D 스캔에 의한 동작시 체표 변화 고찰 및 2D 체표면 전개

정연희(Yeonhee Jeong),홍경희(Kyunghi Hong) 한국생활과학회 2010 한국생활과학회 학술대회 Vol.2010 No.하계

The First Report of Nadifloxacin-Resistant Propionibacterium acnes Isolated from a Patient

Hyunjin Hong,Hye-Ran Nam,Gwang-Yeol Joh,Yeonhee Lee 서울여자대학교 자연과학연구소 2012 자연과학연구논문집 Vol.24 No.-

This is the first report of nadifloxacin-resistant Propionibacterium acnes SKA109. SKA109 was isolated from a patient who was never treated with nadifloxacin before. Its MICs to various quinolones were 8 to 16 fold higher than MICs of the type strain. Especially P. acnes SKA109 was resistant to nadifloxacin which was newly introduced in acne treatment and have been prescribed in Korea since 2008. 이 보고는 나디플록사신 내성 Propionibacterium acnes에 관한 첫 보고이다. Propionibacterium acnes SKA109는 나디플록사신 치료를 받은 경험이 없는 환자로부터 분리하였으며, 퀴놀론 항생제에 대한 MIC가 8-16으로 매우 높았고, 특히 나디플록사신에 강한 내성을 보였다. 나디플록사신은 2008년 이후 한국에서 사용되었으며 그 이전에는 사용된 적이 없는 새로운 항생제이다.

Transfer of Antimicrobial-Resistant Escherichia coli and Resistance Genes in a Child Care Center

( Hyunjin Hong ),( Yeonhee Lee ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.3

Several reports describe antimicrobial-resistance transfer among children and the community in outbreak situations, but transfer between a child and a caregiver has not been examined in child care facilities under normal circumstances. We investigated the transfer of antimicrobial-resistance genes, resistant bacteria, or both among healthy children and teachers. From 2007 to 2009, 104 Escherichia coli isolates were obtained from four teachers and 38 children in a child care center. Twenty-six cephem-resistant isolates were obtained from children in 2007 and 2008. In 2009, cephem-resistant isolates were detected in children as well as a teacher. Nalidixic acid-resistant isolates from the same teacher for 3 years showed low similarity (<50%) to each other. However, an isolate from a teacher in 2007 and another from a child in 2008 showed high similarity (87%). Pulsed-field gel electrophoresis revealed 100% similarity for four isolates in 2007 and one isolate in 2008, and also similarity among seven isolates carrying the virulence gene (CNF1). This study yielded the following findings: (1) a gene for extended-spectrum β-lactamase was transferred from a child to other children and a teacher; (2) a nalidixic acid-resistant isolate was transferred from a teacher to a child; and (3) a virulent bacterium was transferred between children.

Investigation of improved adhesion between Cu film and polyimide by the PSII-EIAMAD technique

Lee, Yeonhee,Hong, Ju Hi,Chun, Hyejin,Han, Seunghee Heyden & Son 2006 Surface and interface analysis Vol.38 No.4

<P>Plasma source ion implantation (PSII) is a relatively simple and effective ion implantation/deposition technique for the surface modification of materials. In PSII, a substrate is immersed in the plasma, and negative, high-voltage pulses are applied to accelerate ions into the substrate in order to modify the surface properties of materials.</P><P>PSII technique combined with energetic ion-assisted mixing and deposition (EIAMAD) was used to improve the adhesion between the Cu film and polyimide. Cu films processed with ion-assisted mixing showed higher adhesion strength than that of not processed or plasma-cleaned ones. Cu films on polyimide substrate were deposited by using different ion species to investigate the ion effect on the interface mixing. Argon ion bombardment led to more adhesive and gradient layers as a function of ion energy and ion dose. The adhesion strength was determined by the 90° peel test. The characterization of Cu-deposited polyimide, generated with ion-assisted mixing by PSII, was performed by AES, SEM, and AFM. Our results suggested that PSII-EIAMAD was a very useful method to grow Cu films with good adhesion properties on polyimide at room temperature. Copyright © 2006 John Wiley & Sons, Ltd.</P>

Identification of Elements Responsible for Maternally-Silenced Imprinted Gene Expression of Upward Curly Leaf1, an F-box Protein Gene that Regulates Curly Leaf in Arabidopsis

Jooyeon Hong,Jaehoon Lee,Cheol Woong Jeong,Janie Sue Brooks,Yeonhee Choi,Jong Seob Lee 한국식물학회 2020 Journal of Plant Biology Vol.63 No.5

Upward Curly Leaf 1 (UCL1) is an Arabidopsis thaliana E3 ligase that targets the Curly Leaf (CLF) SET-domain polycomb-group (PcG) protein for degradation via the ubiquitin-26S proteasome system. UCL1 is a paternally-expressed imprinted gene in the endosperm. To precisely locate the promoter elements required for UCL1 imprinting pattern, various gene constructs were created in which the imprinting control region (ICR), endosperm-specific expression (ENSE) element, and/or the linker sequence were altered. By fusing these constructs with a GUS reporter gene, GUS expression patterns were monitored after reciprocal crosses with wild-type Columbia-0 allowing the determination of parent-of-origin expression. Analysis of publicly-available data on the UCL1 promoter region facilitated the search for allele-specific DNA and H3K27 methylation patterns. Overall, three promoter elements are required for maternal repression of UCL1; the ICR sequence located from − 2.5 to − 2.4 kb upstream of the translation start site, a differentially methylated region 2 (DMR2) that overlaps the short ATLINE1-1 transposable element in the linker region, and a minimal 271 bp ENSE element. In addition, DNA methylation patterns in the DMR2 contribute to the repression of the maternal UCL1 allele. Our findings would help to understand how parent-of-origin epigenetic patterns are created and maintained in the endosperm.