• 제목/요약/키워드: MC3T3

검색결과 485건 처리시간 0.059초

Linearly Constrained Constant Modulus Algorithm을 이용한 MC-CDMA 시스템에서의 MAI 완화 기법 (An Multiple Access Interference Mitigation Technique Using Linearly Constrained Constant Modulus Algorithm in MC-CDMA Systems)

  • 김동주;김주응;정성순;홍대식;강창언
    • 한국통신학회논문지
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    • 제27권1A호
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    • pp.73-79
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    • 2002
  • 본 논문에서는 MC-CDMA 시스템에 적용 가능한 LCCMA(Linearly Constrained Constant Modulus Algorithm)와 HIC(Hybrid Interference Canceller)형태의 두 가지 간섭 제거 구조를 제안하였다. 제안된 구조는 사용자의 확산 부호만을 요구하므로 여러 가지 제한이 있는 이동국에서도 적용이 가능한 장점이 있다. 이와 더불어, 본 논문에서는 LCCMA와 PIC(Parallel Interference Canceller)를 결합한 새로운 구조의 HIC를 제안하였다. 다양한 환경에서 Monte Carlo 모의시험이 수행한 결과, 제안된 LCCMA 및 HIC 구조를 사용한 시스템이 역방향 링크와 순방향 링크에서 각각 MRC(Maximum Ratio Combining)와 EGC(Equal Gain Combining)를 사용한 시스템보다 실험 환경에 따라 1.4~3배정도 용량이 증가되며, MRC나 EGC에서 얻을 수 없었던 경로 다이버시티의 이용이 가능하여, 경로수가 증가할 경우 성능이 향상됨을 실험을 통하여 확인하였다.

Emodin stimulates the osteoblast differentiation via activating bone morphogenetic protein-2 gene expression at low concentration

  • Cheon, Myeong-Sook;Lee, Su-Ui;Kim, Ho-Kyoung;Kim, Young-Sup;Min, Yong-Ki;Kim, Seong-Hwan
    • 한국한의학연구원논문집
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    • 제13권1호통권19호
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    • pp.139-145
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    • 2007
  • Emodin is one of the main active components of a traditional Korean medicine isolated from the root and rhizomes of Rheum palmatum L. In this study, of 222 natural compounds to evaluate the anabolic activities, emodin activated bone morphogenetic protein (BMP)-2 promoter in the differentiation process of mouse osteoblastic MC3T3-E1 cells. Emodin was shown to significantly stimulate the activity and expression of alkaline phosphatase, an earlyphase marker of osteoblastic differentiation, on the differentiation day 7, and induce the osteopontin mRNA expression from the differentiation day 14. In addition, low concentration (up to 5 M) of emodin dramatically promoted the induction of mineralization in MC3T3-E1 subclone 4 cells. The stimulatory effect of emodin on the osteoblast differentiation/mineralization could be associated with its potential to stimulate the BMP-2 gene expression. Although further studies are needed to determine the precise mechanism, this study suggests that the use of herbal medicine containing natural compounds with anabolic activity such as emodin could have a beneficial effect on bone health.

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Longan (Dimocarpus longan Lour.) Fruit Extract Stimulates Osteoblast Differentiation via Erk1/2-Dependent RUNX2 Activation

  • Park, Seoyoung;Kim, Joo-Hyun;Son, Younglim;Goh, Sung-Ho;Oh, Sangtaek
    • Journal of Microbiology and Biotechnology
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    • 제26권6호
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    • pp.1063-1066
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    • 2016
  • Longan (Dimocarpus longan Lour.) has been used as a traditional oriental medicine and possesses a number of physiological activities. In this study, we used cell-based herbal extract screening to identify longan fruit extract (LFE) as an activator of osteoblast differentiation. LFE up-regulated alkaline phosphatase (ALP) activity, induced mineralization, and activated Runx2 gene expression in MC3T3-E1 cells. Furthermore, treatment of MC3T3-E1 cells with LFE promoted the phosphorylation of extracellular signal-regulated kinase1/2 (Erk1/2); however, abrogation of Erk1/2 activation with PD98059 resulted in down-regulation of the phospho-SMAD1/5/8 and Runx2 levels, which in turn reduced the ALP activity. Our findings suggest that LFE exerts its osteogenic activity through activation of the ERK signaling pathway and may have potential as an herbal therapeutic or a preventive agent for the treatment of osteoporosis.

Neuroprotective Effect of Aqueous Extract of Polygala tenuifolia Willdenow on Nitric Oxide-induced Apoptosis in SK-N-MC Cells

  • Kim, Young-Giun;Song, Yun-Kyung;Lim, Hyung-Ho
    • 대한한의학회지
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    • 제31권3호
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    • pp.55-65
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    • 2010
  • Background: Nitric oxide (NO) is a reactive free radical gas and a messenger molecule. NO has many physiological functions, but excessive NO production induces neurotoxicity. Objective: The present study investigated whether the aqueous extract of Polygala tenuifolia Willdenow possesses a protective effect on NO-induced apoptosis in human neuroblastoma cell line SK-N-MC. Method: For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and caspase-3 enzyme assay were performed. Result: Sodium nitroprusside (SNP) exposure significantly decreased the viability of cells. The cells treated with SNP exhibited several apoptotic features such as increasing of Bax expression, caspase-3 enzyme activity and inhibiting of Bcl-2 expression. On the other hand, the viability of cells pre-treated with the aqueous extract of Polygala tenuifolia Willdenow was increased dose-dependently. The cells pre-treated for 1 h with the aqueous extract of Polygala tenuifolia Willdenow followed by treatment with SNP showed a decreased occurrence of apoptotic features like decreasing Bax expressions, caspase-3 enzyme activity and increasing Bcl-2 expressions. The aqueous extract of Polygala tenuifolia Willdenow reduced apoptotic cell death in neuroblastoma cell line SK-N-MC through the inhibition of Bax-dependent caspase-3 activation and the increasing of Bcl-2 expression. Conclusion: Based on the present results, it is possible that Polygala tenuifolia Willdenow has therapeutic value for the treatment of a variety of NO-induced brain diseases.

병원성 Mycobacteria의 세포표면항원간의 항원적 상관 관계 (Cell Surface Antigenic Relationship of Pathogenic Mycobacteria)

  • 권혁한;;김상재
    • Tuberculosis and Respiratory Diseases
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    • 제40권5호
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    • pp.483-494
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    • 1993
  • 석탄산으로 사멸한 균으로 감작시켜 얻은 토끼 항혈청으로 주요 병원성 mycobacteria의 세포 표면항원간의 항원적 상관관계를 효소결합면역분석법으로 관찰하였다. M, avium-intracellulare(MAI) 항혈청을 이용한 동종 및 이종반응 분석결과를 보면 동종내 항원적 상관관계는 매우 가깝고 M. scrofulaceum(MG)을 포함하면 MAIS군내 종간 항원적 관계도 가까웠다. MAI 혈청이 M. chelonei(MC), fortuitum(MF), nonchromogenicum(MNC), terrae(MTR) 및 triviale(MTV)와는 반응하지 않거나 미약하게 반응하지만 M. kansasii(MK)와 결핵균과는 강하게 반응했다. 그러나 후자의 두균종으로 흡수해도 MAI 혈청의 동종반응은 감소되지 않았다. M. avium(MA) (K40004) 항혈청은 M. intracellulare(MI) 균주를 제외한 다른 균들과는 미약하게 반응했고 항원적 상관관계가 가까운 MI와 MG로 흡수하면 동종반응의 50~89%가 감소했다. MI 혈청의 종내반응이 종간반응보다 물론 더 강하지만 공유항원량의 크기에 따라 달랐다. MI균주 중 N-260D, N-260R, N-260T 및 K41014간의 항원적 상관관계가 N-242D, N257T, N281D 및 N275T와의 관계보다 더 가깝게 나타났다. MNC 항혈청은 MC와 MTV를 제외하고는 강한 교차반응을 보여주었다. 종내 항원적 상관관계 다음으로는 MTR와 MG(K30003)과 가까웠다. NC-3 혈청은 MA, MC 및 MF와 상당한 반응력을 나타내지만 NC-11은 그렇지 않았다. MTR 항혈청은 MI와 강하게 반응하지만 MI로 흡수한다고 해서 그들의 동종반응이 감소하지 않는 것으로 보아 MTR 표면에 공유항원이 많지 않음을 보여주었다. MTR과 MNC, MC 및 MF 사이에도 상당량의 공유항원이 있음이 알려졌다. MTR 가운데 T-8 혈청과는 달리 T-13 항혈청은 MA, MG, MK 및 MTB와 강하게 교차반응하였다. 이상의 실험으로 밝혀진 mycobacteria의 항원적 상관관계가 각종 생물학적 및 생화학적 방법으로 갈라놓은 분류군과 잘 일치하고 있었다.

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