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.

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.

Research Articles : Geographic Genetic Contour of A Leaf Beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), on the Basis of Mitochondrial COI Gene and Nuclear ITS2 Sequences

( Joong Won Park ),( Sun Young Park ),( Ah Rha Wang ),( Min Jee Kim ),( Hae Chul Park1 ),( Iksoo Kim ) 한국잠사학회 2011 International Journal of Industrial Entomology Vol.23 No.1

The leaf beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01~CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01~ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (≥87%), whereas ITS2 provided only one sequence type group with a high nodal support (≥92%). The result of COI gene sequence may suggest the presence of historical biogeographic barriers that bolstered genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

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>

단신 : 실리콘의 염소화반응에 의한 사염화규소 제조

박균영 ( Kyun Young Park ),이미선 ( Mi Sun Lee ),김민철 ( Min Cheol Kim ),이찬희 ( Chan Hee Lee ),박회경 ( Hoey Kyung Park ),강태원 ( Tae Won Kang ),정해성 ( Hae Seong Jeong ),한경아 ( Kyoung Ah Han ),허원회 ( Weon Hoe Huh ),유지 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.3

The chlorination of a metallurgical-grade silicon was carried out in a fluidized bed reactor, 25 mm in diameter. The flow rate of the chlorine admitted into the reactor was 0.2 L/min and that of the carrier nitrogen was 0.8~1.0 L/ min. The reactor temperature was maintained at 450℃ and the temperature of the coolant at the SiCl4 condenser was at -5℃. The SiCl4 yield increased with increasing the mole fraction of chlorine in the feed gas, exhibiting 28% at the mole fraction of 0.2. Further increase of the chlorine mole fraction was not attempted in a worry that the reactor might be failed due to the high exothermicity of the reaction. The production of SiCl4 from silicon by fluidized bed chlorination was demonstrated on a laboratory scale, which is a stepping stone for future studies under more severe conditions toward industrial application.

대황의 항산화 효과 및 타이로시네이즈 저해 활성

김정은 ( Jung Eun Kim ),박찬하 ( Chan Ha Park ),오대석 ( Dae Seok Oh ),이승연 ( Seung Yeon Lee ),장세훈 ( Se Hun Jang ),홍지연 ( Jee Yeon Hong ),민혜진 ( Hye Jin Min ),박수아 ( Su Ah Park ),원두현 ( Doo Hyun Won ),박수남 ( Soo Nam 대한화장품학회 2011 대한화장품학회지 Vol.37 No.4

본 연구에서는 대황 추출물의 항산화 활성, 타이로시네이즈(tyrosinase) 저해 활성을 확인하였다. 대황의 50 % 에탄올 추출물, 에틸아세테이트(ethyl acetate) 분획, 아글리콘(aglycone) 분획으로 실험을 진행하였다. 대황 추출물들의 DPPH (1,1-diphenyl-2-picrylhydrazyl) 소거활성(FSC₅₀)은 대표적인 항산화제인 (+)-α-tocopherol보다 낮은 것으로 나타났다. Luminol 발광법을 이용한 Fe³⁺-EDTA/H₂O₂ 계에서 생성된 활성산소종에 대한 아글리콘 분획의 소거활성(총 항산화능, OSC₅₀)은 0.265 μg/mL로 매우 큰 활성을 나타내었다. 대황 추출물의 rose-bengal로 증감된 ¹O₂에 의한 적혈구 파괴에 대한 세포보호 효과는 모든 분획에서 농도 의존적(1∼50 μg/mL)으로 증가하였으며, 특히 아글리콘 분획은 10 μg/mL 농도에서 τ₅₀이 757.0 min으로 높은 세포 보호 활성을 나타내었다. 대황 추출물 중 아글리콘 분획의 타이로시네이즈 저해활성(IC₅₀)은 11.20 μg/mL으로 226.88 μg/mL인 알부틴(arbutin)보다 큰 활성을 보여주었다. 이상의 결과들로부터 대황 추출물은 활성산소종을 소거하는 항산화제로 이용가능하며, 특히 아글리콘 분획의 현저한 항산화 작용 및 큰 타이로시네이즈 저해 효과로부터 이들 분획 또한 화장품원료로서 응용 가능성이 큼을 알 수 있었다. In this study, the antioxidative effects and inhibitory activities on tyrosinase of Rheum undulatum (R. undulatum) L. extracts were investigated. 50 % ethanol extract, ethyl acetate and aglycone fractions of R. undulatum L. were used in experiments. The DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activities (FSC₅₀) of R. undulatum L. extracts was lower than (+)-α-tocopherol, known as a typical antioxidant. Reactive oxygen species (ROS) scavenging activities (OSC₅₀) of aglycone fraction on ROS generated in Fe³⁺-EDTA/H₂O₂ system using the luminol-dependent chemiluminescence assay showed the most prominent effect at a concentration of 0.265 μg/mL. The cellular protective effects of extract/fractions of R. undulatum L. on the rose-bengal sensitized photohemolysis of human erythrocytes were increased in a concentration dependent manner (1 ~ 50 μg/mL). Especially, aglycone fraction in 10 μg/mL concentration showed the most protective effect among extracts (τ₅₀, 757.0 min). The inhibitory effects (IC₅₀, 11.20 μg/mL) on tyrosinase of aglycone fraction was much higher than arbutin (226.88 μg/mL), known as a whitening agent. These results indicate that R. undulatum L. extracts can be used as antioxidant. Particularly, aglycone fraction of R. undulatum L. showed superior antioxdative activity and high inhibitory effect on tyrosinase. Therefore, aglycone fraction of R. undulatum L. could be applicable to new functional cosmetics.

Biaryl Library의 고체상 합성

박민아,조철희,박광용 한국공업화학회 2003 응용화학 Vol.7 No.2

Biaryl library was prepared by the solid-phase cross-coupling reaction of polymer-bound arenesulfonates with arylmagnesium bromides in the presence of nickel(0) catalyst. This approach seems to be useful for the preparation of various non-functionalized oligophenyl library on solid-phase organic synthesis(SPOS).

한국인에서 구강상피세포를 이용한 발암물질 대사효소의 유전자 다형성에 관한 연구

최민아,박해준,정원윤,이재원,이정복,박광균 대한암예방학회 2002 Journal of cancer prevention Vol.7 No.3

한국인 강박장애와 Val-158-Met Catechol-O-Methyltransferase 유전자 다형성 간의 상관성 연구

천근아,김세주,김찬형,구민성,남윤영,박성혁,이홍식 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.5

목적 COMT(Catechol-O-Methyltransferase) 효소는 도파민성과 노어아드레날린성 체계의 조절에서 매우 중요한 작용을 하며 염색제 22q11에 위치해 있다. 일부의 강박장애 환자들은 도파민 차단제에 좋은 치료 반응을 보이며 이런 현상은 COMT가 강박장애의 병인론에 역할을 하고 있을 가능성을 말해준다. Val-158-Met COMT 유전자의 다형성은 효소의 감소를 유도하는 L(저활성) 대림형질, 활성의 증가를 유발하는 H(고활성) 대립형질로 알려져 있으며 L 대립형질 또는 LL 유전형이 강박장애와 연관이 있다는 보고가 있으나, 아직까지 강박장애와 COMT 다형성 사이의 연관성에 대한 연구결과들은 일관되지 않다. 따라서 본 연구에서는 한국인 강박장애 환자들을 대상으로 Val-158-Met COMT 유전자의 다형성과의 연관성을 알아보고자 하였다. 방법 2002년 3월부터 2004년도 2월까지 약 24개월동안 서울지역 일 대학병원과 경기지역 일 대학병원 강박장애 클리닉을 방문하여 강박장애로 진단받은 124명의 환자들을 연구대상으로 하였고 정상 대조군으로는 나이와 성별을 고려하여 자원자 170명이 선별되어 포함되었다. 강박장애군과 정상 대조군의 혈액으로부터 유전자 추출 후 COMT 유전자 형벌 (genotyping)을 시행하였다. 다형성을 H/H 와 H/L, L/L 유전형으로 나눈 뒤 강박장애와 정상대조군 사이의 유전자 빈도를 카이 검정법으로 비교하여 연관성을 관찰하었다. 또한 강박장애 환자들에게 시행한 YBOCS로부터 측정한 강박장애 심각도 및 Hamilton Depression Raing Scale (HDRS) 총점과 COMT 유전자 다형성 사이의 연관성을 비교하였다. 결과 본 연구 결과 한국인 강박장애와 COMT 다형성 간에는 유의한 상관성이 관찰되지 않았다. YBOCS 심각도와 COMT 유전자형과의 유의한 연관성이 관찰되지 않았다. 그러나, 강박장애 환자군들의 COMT 유전자형 세 군 사이의 우울증상 점수에서는 유의한 차이가 관찰되었다. 결론 한국인에서 강박장애와 COMT 유전자 다형성 사이에는 연관성이 없었다. 그러나, COMT의 H 대립형질과 강박장애 군에서 공존하는 우울증상 척도가 유의한 연관성을 보인 현상은 COMT 유전자의 다형성이 강박장애의 공존 우울증상에 영향을 미칠 수 있는 가능성을 시사한다고 생각된다. Objectives : The definite cause of obsessive-compulsive disorder (OCD) is still unknown. Evidences from familial, twin and segregation studies support the role of a genetic factor. There are also growing evidence indicating that OCD has specific neurochemical and neuroanatomical basis. Derived from the effectiveness of treatment with dopamine receptor blocker in certain part of OCD patients (eg. SSRI treatment-resistant OCD), several candidate genes related to dopamine dysregulation have been hypothesized to play an important role in the development of OCD. One of them is the Catechol-O-Methyltransferase (COMT) gene. The aim of this study was to investigate the association between COMT and OCD in Korean population. Methods : 124 OCD patients and 170 normal controls participated in this study. Genomic DNA was extracted from their blood. The genotypes and allele frequencies of the COMT polymorphism between OCD group and control group were compared. We investigated the association between severity of OCD assessed by Yale-Brown obsessive compulsive symptom scale (YBOCS) and Hamilton depression rating scale (HDRS) scores and COMT polymorphism. Results : In this case-control study, we could not find any association between COMT gene polymorphism and development of OCD. In OCD group, patients with H/H genotype had significantly higher scores for the HDRS than those with H/L or L/L genotype. Conclusion : In this study, there was no difference in genotype distributions of COMT between OCD and control groups. However, H/H genotype of COMT gene polymorphism might be related to depressive symptoms in OCD patients.

多孔性 PTCR 材料에서 첨가제의 입도가 특성에 미치는 影響에 관한 硏究

서민아,박성,이병하 明知大學校 産業技術硏究所 1997 産業技術硏究所論文集 Vol.16 No.-

It is know that PTCR thermistor of powder based on BaTiO₃and fabricated by adding a some dopants to semiconductor and little amount of acceptors to higher ratio of resistivity. Those powder has shown good electrical properties for PTCR ceramics will be high than 1350℃ with 6 or 7 orders of magnitude resistivity as PTCR effect. Also acceptor add has been used for in order to higher PTCR effect. In this research, it is observed that the content of Sb₂O₃dopant and SiO₂ liquid sintering additive influence PTCR characteristics of BaTiO₃ ceramics. In addition of graphite by special synthesized process and be obtain porous PTCR ceramics for excess oxygen vacancis that remained to be uncompensated by oxygen exist near the grain boundaries I excess of the number of acceptor states being there. Also it is researched that particle size of Graphite influence size of pore and characteristics of BaTiO₃ceramics