• 환경생물
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• 제29권4호
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• pp.258-264
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• 2011

Glutathione (GSH)은 직접적으로 활성산소종을 제거하거나 GSH peroxidase와 같은 활성산소종 제거 효소의 조효소로써, 산화적 스트레스로부터 세포를 방어하는 데 중요한 역할을 한다. GSH peroxidase는 두 분자의 GSH을 이용해 세포 내 과산화수소를 물로 전환한다. $N$-acetyl-L cysteine (NAC)는 항산화제 중 하나로 세포 내 GSH의 전구물질로 이용된다. 본 연구는, 0mM에서 20mM의 NAC 단독 처리 또는 100 Gy 감마선과 복합 처리한 효모세포에서 GSH peroxidase를 코드화(encoding)하는 유전자인 $GPX1$과 $GPX2$의 전사적 발현을 통해 GSH, NAC와 GSH peroxidase의 연관성을 알아보았다. $GPX1$과 $GPX2$의 전사적 발현은 NAC와 100 Gy 감마선에 의해 유도되었다. 조사된 효모세포에서 NAC의 증가 농도에 따라 GSH peroxidase 두 유전자의 발현은 감소되었다. 이러한 결과로, NAC에 의해 증가된 세포 내 GSH는 GSH peroxidase 유전자의 전사적 발현을 유도하며, NAC는 감마선으로부터 생성된 활성산소종 직접적 제거와 GSH peroxidase 유전자의 전사적 발현을 유도함으로써 세포를 보호할 수 있다는 것이 밝혀졌다.

• Journal of Life Science
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• 제11권1호
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• pp.57-64
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• 2001

The cDNA encoding human NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc GalNac ${\alpha}$2,6-Sialyltransferase (hST6GalNac IV) was isolated by screening of human fetal liver cDNA library with a DNA probe generated from the cDNA sequence of mouse ST6Gal NAc IV (mkST6GalNAc IV). The cDNA sequence included an open reading frame coding for 302 amino acids, and comparative analysis of this cDNA with mST6GalNAc IV showed that each sequence of the predicted coding region contains 88% and 85% identifies in nucleotide and amino acid levels, respecively. The primary structure of this enzyme suggested a putative domain structure, like that in other glycosyltransferases, consisting of a short N-terminal cytoplamic domain, a transmembrane domain and a large C-terminal active domain. This enzyme expressed in COS-7 cells echibited transferase activity toward NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc, fetuin and GM1b, although the activity toward the later is very low, no significant activity being detected toward Gal${\beta}$ 1,3Gal NAc or asialofetuin, the other glycoprotein substrates tested. The $^{14}$ C-sialylated residue of fetuin sialylated by this enzyem with CMP-[$^{14}$C]NeuAc was sensitive to treatment with ${\alpha}$2,8-specific sialidase of Vibrio cholerae but resistant to treatment with ${\alpha}$2,3-specific sialidase (NaNase I), and ${\alpha}$2,3- and ${\alpha}$2,8-specific sialidase of Newcastle disease virus. These results clearly indicated that the expressed enzyme is a type of GalNAc ${\alpha}$2,6-sialyltransferase like mST6GalNAc IV, which requires sialic acid residues linked to Gal${\beta}$1,3GalNAc-residues for its activity.

• Membrane and Water Treatment
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• 제9권3호
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• pp.195-203
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• 2018

N-acetylcysteine (NAC) has been widely used as an initial mucolytic agent and is generally used as an antioxidant to help alleviate various inflammatory symptoms. NAC reduces bacterial extracellular polymeric substances (EPS) production, bacterial adhesion to the surface and strength of mature biofilm. The efficacy has been shown to inhibit proliferation of gram-positive and gram-negative bacteria. In membrane bioreactor (MBR) processes, which contain a variety of gram negative bacteria, biofilm formation has become a serious problem in stable operation. In this study, use of NAC as an inhibitor of biofilm contamination was investigated using the center for disease control (CDC) reactors with MBR sludge. Biomass reduction was confirmed with CLSM images of membrane surfaces by addition of NAC, which was more efficient as the concentration of NAC was increased to 1.5 mg/mL. NAC addition also showed decreases in EPS concentrations of the preformed biofilm, indicating that NAC was able to degrade EPS in the mature biofilm. NAC addition was also effective to inhibit biofilm formation by MBR sludge, which consisted of various microorganisms in consortia.

• International Journal of Oral Biology
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• 제33권4호
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• pp.187-195
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• 2008

Reparative dentine formation requires newly differentiated odontoblast-like cells. Therefore, identification of the molecule that stimulates the odontogenic differentiation of precursor cells in the tooth pulp will be helpful for the development of strategies to repair damaged pulp. In this study, we examined the effect of N-acetylcysteine (NAC) on the odontogenic differentiation of MDPC-23 cells, a mouse odontoblast-like cell line derived from dental papilla, and primary cultured rat dental papilla cells (RDPCs). NAC (1-30 mM) suppressed production of reactive oxygen species in MDPC-23 cells in a dose-dependent manner. Although 5 to 20 mM NAC did not alter MDPC-23 cell proliferation, 1 or 30 mM NAC significantly inhibited it. NAC enhanced mineralized nodule formation and the expression of several odontoblast differentiation-associated genes in both RDPCs and MDPC-23. This NAC stimulatory effect was significant, even at concentrations lower than 1 mM. However, NAC did not stimulate expression of bone morphogenetic protein-2, -4, or -7, which are known to enhance odontogenic differentiation. Since reactive oxygen species are also involved in the pulp toxicity of resin-based restorative materials, these results suggest that NAC may be a promising candidate for supplementation of dental restorative materials in order to enhance reparative dentine formation.

• 생명과학회지
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• 제16권6호
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• pp.955-959
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• 2006

단백질의 serine 및 threonine 잔기에 O-linked N-acetylglucosamine (O-GlcNAc)의 수식은 핵단백질과 세포질 단백질의 주요 조절인자로 부각되고 있다. 본 연구에서는 GlcNAc를 인산화시켜 GlcNAc 6-phosphate로 만드는 GlcNAc kinase (NAGK, EC2.7.1.59)의 세포내 표현을 면역화학적 방법으로 조사하였다. 배양한 해미신경세포에서 NAGK는 가지돌기를 따라 점박이(punctae)를 형성하였으며, 이 점박이들은 caveolin-1 혹은 flotillin 항체에도 염색이 되었다. 이들은 각각 caveolac와 lipid raft의 표지단백질이기 때문에 본 연구결과는 NAGK가 세포막의 이러한 특수 미세부분(microdomain)에 존재함을 의미하며, 이 미세부분에서 아직 알려지지 않은 어떤 기능을 할 것을 시사한다.

• 대한의생명과학회지
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• 제24권3호
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• pp.206-212
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• 2018

Depression is a type of mood disorder characterized by hypochondriasis, decreased appetite, and insomnia. Depression is a disease that affects more than 100 million people worldwide. 2-Nonadecanone (NAC) is a bioactive substance that constitutes Fomes fomentarius, and NAC is expected to have an antidepressant effect. By using the forced swimming test (FST), we investigated the effects of treatment with NAC on immobility subacutely in rats after oral dosing once a day for 2 days. Serum levels of cytokine interleukin-1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were determined by enzyme-linked immunosorbent assay (ELISA). Nuclear factor-2 (Nrf-2) and inducible nitric oxide synthases (iNOS) were analyzed by western blot method. NAC dose-dependently decreased immobility in the FST. NAC dosedependently decreased FST-induced increase of cytokine levels, as manifested by significantly stronger effects on $IL-1{\beta}$ and $TNF-{\alpha}$ levels at higher doses than the lowest dose of NAC. Western blot analysis showed that Nrf-2 was significantly lower in the NAC-treated group than in the disease-induced group. The iNOS results were also significantly lower in the NAC-treated group than in the other groups. Considering FST results, the antidepressant effect of NAC is effective. Considering the results of cytokine and protein expression, this anti-depressant effect may be related to the anti-inflammatory effect. Therefore, it can be said that the anti-inflammatory effect of NAC increases the antidepressant effect in the FST experiment.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.8-11
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• 2009

본 논문에서는 Extreme 스위치와 Cisco 라우터를 이용하여 가상의 네트워크를 구현하였으며 PIX 방화벽을 통해 외부 네트워크로부터의 보안을 강화하였고 내부 네트워크에 대한 보안 문제점은 802.1X 기반의 인증방식을 사용한 NAC를 적용시켜 구현함으로써 외부와 내부 네트워크의 통합적인 보안 플랫폼을 구성하였다.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.706-709
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• 2005

The absence of the nipple-areolar complex(NAC) in men are seldom stated, as a result of trauma, burn, mastectomy, or after the correction of extreme bilateral gynecomastia. A total of 50 healthy men aged 21 to 27 years were examined. We recorded the configuration (dimensions and shape) and the location of the NAC with respect to fixed skeletal anatomic landmarks. Of the 50 subjects examined, 44 had oval and 6 had a round NAC. The mean diameter for a round NAC was 24.3 mm. The center of the NAC was in the fourth intercostal space in 41 volunteers and in the fifth intercostal space in 9 of the subjects. To localize the NAC on the chest wall, at least three reproducible measurements proved to be necessary, composed of a horizontal line(distance from the midsternal line to the nipple, A), a medial oblique line(distance from the sternal notch to the nipple, B) and a lateral oblique line(distance from the acromioclavicular joint to the nipple, C). Using these three parameters, we recommend that the appropriate location can be calculated derived from the circumference of the chest.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.306-311
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• 2002

O-linked N-acetylglucosamine (O-GlcNAc) is an abundant posttranslationally modified compound in eukaryotic cells. Human O-GlcNAc transferase (OGT) was produced as a maltose binding protein (MBP) fusion protein, which showed significant catalytic activity to modify recombinant Sp1, transcription factor. To facilitate the production of O-GlcNAc modified proteins, instead of using the tedious in vitro glycosylation reaction or expression in eukaryotic cells, a MBP-fusion OGT expression vector (pACYC184-MBPOGT) was constructed using pACYC184 plasmid, which could coexist with general prokaryotic expression vectors containing ColE1 origin. By cotransforming pACYC184-MBPOGT and pGEX-2T vectors into Escherichia coli BL21, intracellular O- GlcNAcylated proteins could be obtained by a simple purification procedure. It is expected that this may be a useful tool for production of O-GlcNAc modified proteins.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.1385-1388
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• 2009

오늘날 IT 환경의 변화는 내부 네트워크에서 새로운 보안위협이 발생하면서, 네트워크에 접근하는 접속단말기의 보안성을 강제화 할 수 있는 보안 인프라로서, NAC(Network Access Control)의 필요성이 증대고 있다. 최근 u-Campus 네트워크에서 다양한 보안위협에 대한 문제점을 해결하기 위해 NAC 도입 및 구축의 필요성이 높아지고 있지만, 기존 보안 솔루션과의 복잡한 연계관계 및 운영체제에 대한 유연성 결여 등 여러 문제가 도출되고 있다. 따라서 본 논문에서는 u-Campus 내 네트워크 신뢰성 확보를 위해 NAC 도입 및 구축 시 필요한 로드맵을 제시함으로서, 각 대학에서는 효율적인 NAC 솔루션 선택에 필요한 지침이 되며, 다양한 보안 위협을 사전에 방어하여 네트워크의 신뢰성 증진과 무결성을 유지할 수 있는 방안을 제시한다.