A Comparative Experimental Study of the, In-vitro Efficiency of Hypertonic, Saline-Enhanced Hepatic Bipolar and, Monopolar Radiofrequency Ablation

Lee, Jeong Min,Han, Joon Koo,Kim, Se Hyung,Sohn, Kyu Li,Lee, Kyoung Ho,Ah, Su Kyung,Choi, Byung Ihn Korean Radiological Society 2003 Korean Journal of Radiology Vol.4 No.3

옥수수 바이오매스를 함유한 폴리에스터 필름의 물리 화학적 특성과 생분해 특성에 대한 콜드 플라즈마 처리의 영향

송아영(Ah Young Song),오윤아(Yoon Ah Oh),오세준(Se Jun Oh),민세철(Sea Cheol Min) 한국식품과학회 2015 한국식품과학회지 Vol.47 No.2

CP 처리의 CBPE 필름의 물리화학적 특성 및 생분해 특성에 대한 영향을 연구하였다. CP 처리는 CBPE 필름의 인장 강도, 신장률, 그리고 광투과도와 같은 물리적 특성에는 영향을 주지 않았으나, air-CP 처리는 CBPE 필름의 유연성, 수분 방벽 특성, 그리고 인쇄적성을 향상시켰다. Air-CP 처리는 저장 중 CBPE 필름 표면의 조도와 O와 N 원소를 포함한 작용기의 양을 증가시켰고, 인쇄적성, 열분해성, 그리고 미생물 분해성을 향상시켰다. 본 연구에서 CP 처리 후 CBPE 필름 표면에서 보여지는 노화 현상을 XPS 결과를 통해 확인할 수 있었다. 본 연구는 CP 처리가 CBPE 필름을 비롯하여 다른 생분해성 식품 포장재의 물리적 특성과 생분해성을 향상시킬 수 있는 기술로서 적용될 수 있다는 가능성을 보여주었다. The effects of cold plasma (CP) treatments on the physicochemical and biodegradable properties of a corn biomass-containing polyester (CBPE) film were studied. The CBPE film was treated with CP generated by N2, O2, He, Ar, or dry air at 400-900 W and 667 Pa for 10-40 min. The glass transition temperature of the CBPE film (?30.2- ?28.6℃) was not affected by the CP treatment, while the elastic modulus and water vapor permeability decreased (p<0.05). The ink printability was improved by the treatment and the improved printability was maintained during storage for 56 days at room temperature. Roughness of the film increased after treatments and the level of roughness appeared to increase during storage. Heat and microbial biodegradability of the CBPE film was improved by the air-CP treatment (p<0.05). These results have demonstrated the potential of applying CP treatments to improve the flexibility, printability, and biodegradability of CBPE films.

부추 추출물에 의한 Escherichia coli 및 Staphylococcus aureus 의 생육 저해효과

이민경(Min Kyung Lee),이정아(Jeong-ah Lee),박인식(Inshik Park) 한국식품영양과학회 2001 한국식품영양과학회지 Vol.30 No.1

식품오염의 지표로 이용되는 Escherichia coli 와 식중독을 일으키는 Staphylococcus aureus에 대한 부추(Allium tuberosum) 추출물의 항미생물 활성을 검토하고, 그 활성의 열안정성 및 pH 안정성을 조사하였다. 부추 추출물은 미생물의 생육을 저해하였으며 특히 Staphylococcus aureus에서 생육 저해환의 면적이 크게 나타났다. 그리고 paper disc에 50 μL의 부추 추출물을 흡수시켰을 때는 Escherichia coli와 Staphylococcus aureus는 각각 440 ㎟, 609 ㎟의 저해면적을 나타내었으며 부추 추출물의 농도가 높을수록 생육 저해가 현저하였다. 또한 부추 추출물을 68℃에서 30분 또는 98℃ 20분간 열처리 후에도 부추 추출물에 의하여 미생물의 생육은 저해되었다. 그리고 부추 추출물을 pH 2.0에서 3시간 보관 후에도 항미생물활성은 비교적 안정하였다. 그러나 부추 추출물의 항미생물 활성은 투석에 의하여 완전히 활성이 없어졌으며, 따라서 부추 추출물에 존재하는 항미생물 활성은 저분자 물질인 것으로 사료된다. The growth retardation of Escherichia coli and Staphylococcus aureus by heat or acid treated leek (Allium tuberosum) extract was observed. Antimicrobial activity of the leek was the most effective when fresh leek extract was used, but it was stable after heat treatment at 68℃ for 30 min or 98℃ for 20 min. It was also relatively stable after incubated at pH 2.0 for 3 hrs. The antimicrobial activity in leek was not detected after dialysis with molecular weight cutoff of 12,000. Therefore it seems to be small molecule with molecular weight lower than 12,000.

국내외 수용가 맞춤형 수력발전시스템 현대화개발 및 실증

오민환(Min-Hwan Oh),신기석(Ki-Seok Shin),임재황(Jae-Hwang Lim),윤여창(Yeo-Chang Yun),김현아(Hyun-Ah Kim),강석원(Seok-Won Kang),백종명(Jong-Myung Paik),이준용(Jun-Yong Lee) 대한전기학회 2017 대한전기학회 학술대회 논문집 Vol.2017 No.10

근적외선 유도 약물방출을 위한 키토산 미세입자의 제조와 평가

김민아 ( Min Ah Kim ),김미리 ( Miri Kim ),이창문 ( Chang-moon Lee ) 한국키틴키토산학회 2016 한국키틴키토산학회지 Vol.21 No.4

본 연구에서는 근적외선 레이저의 감응성 물질인 멜라닌과 5-FU를 함유한 키토산 미세입자를 제조하고 광열효과와 약물방출실험을 진행하고 다음과 같은 결과를 얻었다. 멜라닌과 5-FU를 함유한 키토산 미세입자는 W/O/W 방법을 통해 성공적으로 제조할 수 있었고, 미세입자는 구형이었으며 비교적 균일하였다. 키토산 미세입자를 농도별로(0.55~2.75 mg/mL) 증류수에 분산시켜 레이저(808 nm, 1.5 W/cm², 5 min)를 조사한 결과, 샘플의 농도와 조사시간이 증가할수록 온도의 변화가 크게 나타났다. 키토산 미세입자로부터 5-FU의 방출실험을 진행한 결과, 레이저를 조사하지 않은 그룹에 비해 레이저를 조사한 그룹에서 약물방출 속도가 증가하는 것을 알 수 있었고, pH 5.0에서 보다 큰 차이를 보였다. 위의 결과를 통해 근적외선을 이용하여 멜라닌을 함유한 키토산 미세입자로부터 약물 방출 속도를 조절할 수 있고 더 나아가 in vivo에서의 국소적 약물 전달 및 효과적인 치료방법으로 사용될 수 있을 것으로 기대할 수 있다. In this study, melanin and 5-fluorouracil (5-FU)-loaded chitosan microparticles were prepared and the drug release profiles from the microparticles were investigated under near infrared (NIR) 808 nm laser irradiation at 1.5 W/cm ² for 5 min. The chitosan microparticles were uniform and spherical in shape. After irradiation of NIR 808 nm laser at 1.5 W/cm² for 5 min, the temperature of the chitosan microparticle solution increased. As the concentration of the chitosan microparticles increases from 0.55 mg/mL to 2.75 mg/mL, the temperature of the microparticle solution increased with irradiation time. Under NIR 808 nm laser irradiation, 32.1±2.3% and 53.7±1.1% of 5-FU from the chitosan microparticles were released at pH 7.4 and 5.0, respectively. In other hand, without laser irradiation 23.9±1.6% and 26.9±2.0% of 5-FU were released from the chitosan microparticles at pH 7.4 and 5.0, respectively. All these results indicate that chitosan microparticles containing melanin could be used as a photo-induced drug release system.

Development of multiplexed analysis for the photocatalytic activities of nanoparticles in aqueous suspension

Lee, No Ah,Kim, Soo Jin,Park, Bong-Jae,Park, Hyun Min,Yoon, Minjoong,Chung, Bong Hyun,Song, Nam Woong Royal Society of Chemistry 2011 PHOTOCHEMICAL AND PHOTOBIOLOGICAL SCIENCES Vol.10 No.12

<P>A multiplexed assay technique to measure the photocatalytic activity (PCA) of nanoparticles (NPs) in aqueous suspension was developed based on the observation of TiO<SUB>2</SUB> NPs-photocatalytic oxidation rate of NADH by monitoring the fluorescence intensities. 96 sample solutions of a small volume (<150 μL) could be assayed in a single run without separation of NPs within 15 min. PCA values can be measured with high sensitivity and low experimental uncertainties through the observation at various concentrations of photocatalyst, substrate, aqueous protons and pH buffer ions in a short measurement time.</P> <P>Graphic Abstract</P><P>A multiplexed assay to measure the photocatalytic activity of nanoparticles in aqueous suspension without separation has been developed based on the fluorescence reading in a 96-well plate platform. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1pp05244f'> </P>

한국산 무우 Peroxidase의 열변성 및 재활성화에 미치는 요인

이경아(Kyung-Ah Lee),홍정민(Jung-Min Hong),김기남(Gi-Nahm Kim),박인식(Inshik Park) 한국식품영양과학회 1990 한국식품영양과학회지 Vol.19 No.4

한국산 무우(Rhapanus sativus) peroxidase의 열안정성에 미치는 요인 및 열처리에 의해 불활성화된 peroxidase의 재활성화에 미치는 요인들을 검토하였다. 효소는 60℃이하의 열처리에는 안정하였으나, 80℃에서는 10분 후에 완전히 불활성화하였다. 효소의 불활성화에 미치는 PH의 효과 PH 6.0에서는 매우 안정하였으나, PH 4.0이하 및 PH 8.0이상에서는 매우 불안정하였다. 효소의 열안정성은 당, 염 및 단백질의 첨가에 의하여 증가하였다. 효소의 재활성화는 PH 9.0에서 재활성화율이 가장 높았으며, 그리고 열에 의한 불활성화와 다르게 첨가한 당, 염 및 단백질에 의해 거의 영향을 받지 않았다. 열에 의해 불활성화된 효소는 환원제인 dithiothreitol의 첨가에 의하여 재활성화가 억제되었다. Factors affecting thermal inactivation and reactivation of korean radish peroxidase were investigated. The enzyme was stable below 60℃, but it was completely inactivated by heat treatment at 80℃ for 10 min. The enzyme was stable at pH 6.0, but it was unstable below pH 4.0 and above pH 8.0. The thermostablity of the enzyme was increased by addition of glucose, sodium chloride and albumin. The inactivated enzyme by heat treatment was reactivated at room temperature. The optimal pH for reactivation of the enzyme was pH of 9.0. The reactivation rate of the enzyme was not affected by addition of glucose, sodium chloride and albumin. The reactivation was completely inhibited by addition of sulfhydryl reagent such as dithiothreitol.

Effects of Hydrogen Plasma Treatment of the Underlying TaSiN Film Surface on the Copper Nucleation in Copper MOCVD

Park, Hyun-Ah,Lim, Jong-Min,Lee, Chong-Mu The Korean Ceramic Society 2004 한국세라믹학회지 Vol.41 No.6

MOCVD is one of the major deposition techniques for Cu thin films and Ta-Si-N is one of promising barrier metal candidates for Cu with high thermal stability. Effects of hydrogen plasma pretreatment of the underlying Ta-Si-N film surface on the Cu nucleation in Cu MOCVD were investigated using scanning electron microscopy, X-ray photoelectron spectroscopy and Auger electron emission spectrometry analyses. Cu nucleation in MOCVD is enhanced as the rf-power and the plasma exposure time are increased in the hydrogen plasma pretreatment. The optimal plasma treatment process condition is the rf-power of 40 Wand the plasma exposure time of 2 min. The hydrogen gas flow rate in the hydrogen plasma pretreatment process does not affect Cu nucleation much. The mechanism through which Cu nucleation is enhanced by the hydrogen plasma pretreatment of the Ta-Si-N film surface is that the nitrogen and oxygen atoms at the Ta-Si-N film surface are effectively removed by the plasma treatment. Consequently the chemical composition was changed from Ta-Si-N(O) into Ta-Si at the Ta-Si-N film surface, which is favorable for Cu nucleation.

O-deGlcNAcylation is required for <i>Entamoeba histolytica</i>-induced HepG2 cell death

Lee, Young Ah,Min, Arim,Shin, Myeong Heon Elsevier 2018 Microbial pathogenesis Vol.123 No.-

<P><B>Abstract</B></P> <P> <I>Entamoeba histolytica</I> is an enteric tissue-invading protozoan parasite that causes amoebic colitis and occasionally liver abscess in humans. <I>E. histolytica</I> can induce host-cell apoptosis by initiating various intracellular signaling mechanisms closely associated with tissue pathogenesis and parasitic immune evasion. O-GlcNAcylation, similar to phosphorylation, is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. However, whether O-GlcNAc alterations in host cells affect <I>E. histolytica</I>-induced cell death and which signal molecules participate in <I>E. histolytica</I>-induced deglycosylation remain unknown. In this study, co-incubation of HepG2 cells with <I>E. histolytica</I> increased DNA fragmentation and LDH release as compared with control cells. Additionally, Gal-lectin-mediated amoebic adherence of live trophozoites to HepG2 cells decreased O-GlcNAcylated protein levels within 5 min. We also observed a rapid decrease in cellular OGT protein level, but not OGA, in HepG2 cells in a contact-dependent manner. Furthermore, HepG2 pretreatment with OGA inhibitors or OGA siRNA prevented <I>E. histolytica</I>-induced O-deGlcNAcylation, DNA fragmentation, and LDH release. Our results suggested that <I>E. histolytica</I>-induced O-deGlcNAcylation in HepG2 cells was an important process required for hepatocyte cell death induced by <I>E. histolytica</I> adherence.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Entamoeba histolytica</I> remarkably induces cell death in HepG2 cells. </LI> <LI> O-GlcNAcylated proteins were rapidly and dramatically reduced in Entamoeba-treated HepG2 cells in a contact-dependent manner. </LI> <LI> Alteration of OGT/OGA expression with OGA inhibitor reduces <I>E. histolytica</I>-induced O-deGlcNAcylation in HepG2 cells. </LI> <LI> Inhibition of OGA activity reduces <I>Entamoeba</I>-induced host cell death in HepG2 cells. </LI> </UL> </P>

Chlorpropamide 2-hydroxylation is catalysed by CYP2C9 and CYP2C19 <i>in vitro</i>: chlorpropamide disposition is influenced by CYP2C9, but not by CYP2C19 genetic polymorphism

Shon, Ji-Hong,Yoon, Young-Ran,Kim, Min-Jung,Kim, Kyoung-Ah,Lim, Young-Chae,Liu, Kwang-Hyeon,Shin, Dong-Hoon,Lee, Chung Han,Cha, In-June,Shin, Jae-Gook Blackwell Science Ltd 2005 British journal of clinical pharmacology Vol.59 No.5

<P>Aims</P><P>We evaluated the involvement of cytochrome P450 (CYP) isoforms 2C9 and 2C19 in chlorpropamide 2-hydroxylation <I>in vitro</I> and in chlorpropamide disposition <I>in vivo</I>.</P><P>Methods</P><P>To identify CYP isoforms(s) that catalyse 2-hydroxylation of chlorpropamide, the incubation studies were conducted using human liver microsomes and recombinant CYP isoforms. To evaluate whether genetic polymorphisms of CYP2C9 and/or CYP2C19 influence the disposition of chlorpropamide, a single oral dose of 250 mg chlorpropamide was administered to 21 healthy subjects pregenotyped for CYP2C9 and CYP2C19.</P><P>Results</P><P>In human liver microsomal incubation studies, the formation of 2-hydroxychlorpropamide (2-OH-chlorpropamide), a major chlorpropamide metabolite in human, has been best described by a one-enzyme model with estimated <I>K</I><SUB><I>m</I></SUB> and <I>V</I><SUB>max</SUB> of 121.7 ± 19.9 µ<SMALL>M</SMALL> and 16.1 ± 5.0 pmol min<SUP>−1</SUP> mg<SUP>−1</SUP> protein, respectively. In incubation studies using human recombinant CYP isoforms, however, 2-OH-chlorpropamide was formed by both CYP2C9 and CYP2C19 with similar intrinsic clearances (CYP2C9 <I>vs.</I> CYP2C19: 0.26 <I>vs.</I> 0.22 µl min<SUP>−1</SUP> nmol<SUP>−1</SUP> protein). Formation of 2-OH-chlorpropamide in human liver microsomes was significantly inhibited by sulfaphenazole, but not by <I>S</I>-mephenytoin, ketoconazole, quinidine, or furafylline. In <I>in vivo</I> clinical trials, eight subjects with the <I>CYP2C9</I>*<I>1/</I>*<I>3</I> genotype exhibited significantly lower nonrenal clearance [*<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.8 ± 0.2 <I>vs.</I> 2.4 ± 0.1 ml h<SUP>−1</SUP> kg<SUP>−1</SUP>, <I>P</I> < 0.05; 95% confidence interval (CI) on the difference 0.2, 1.0] and higher metabolic ratios (of chlorpropamide/2-OH-chlorpropamide in urine: *<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.01 ± 0.19 <I>vs.</I> 0.56 ± 0.08, <I>P</I> < 0.05; 95% CI on the difference − 0.9, − 0.1) than did 13 subjects with <I>CYP2C9</I>*<I>1/</I>*<I>1</I> genotype. In contrast, no differences in chlorpropamide pharmacokinetics were observed for subjects with the <I>CYP2C19</I> extensive metabolizer <I>vs.</I> poor metabolizer genotypes.</P><P>Conclusions</P><P>These results suggest that chlorpropamide disposition is principally determined by CYP2C9 activity <I>in vivo</I>, although both CYP2C9 and CYP2C19 have a catalysing activity of chlorpropamide 2-hydroxylation pathway.</P>