• Molecules and Cells
• /
• 제39권11호
• /
• pp.777-782
• /
• 2016

The innate immune system has evolved to detect and destroy invading pathogens before they can establish systemic infection. To successfully eradicate pathogens, including viruses, host innate immunity is activated through diverse pattern recognition receptors (PRRs) which detect conserved viral signatures and trigger the production of type I interferon (IFN) and pro-inflammatory cytokines to mediate viral clearance. Viral persistence requires that viruses co-opt cellular pathways and activities for their benefit. In particular, due to the potent antiviral activities of IFN and cytokines, viruses have developed various strategies to meticulously modulate intracellular innate immune sensing mechanisms to facilitate efficient viral replication and persistence. In this review, we highlight recent advances in the study of viral immune evasion strategies with a specific focus on how Kaposi's sarcoma-associated herpesvirus (KSHV) effectively targets host PRR signaling pathways.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 춘계학술발표대회
• /
• pp.37.1-37.1
• /
• 2011

Miniaturization of lenses has been widely researched by various scientific and engineering techniques. As a result, micro scaled lens structure could be easily achieved from various fabrication techniques; nevertheless it is still challenging to make nano scaled lenses. This paper reports a novel fabrication method of silicon nanotemplate for nanolens array. The inverse structure of nanolens array was fabricated on silicon substrate by reactive ion etching (RIE) process. This technique has a flexibility to produce different tip shapes using different pattern masks. Once the silicon nano-tip array structure is well-defined using an optimized recipe, it is followed by polymer molding to duplicate nanolens array from the template. Finally, the nanostructures formed on silicon nanotemplate and polymer replica were investigated using FE-SEM and AFM measurements. The nano scaled lens can be manufactured from the same template, also using other replication techniques such as imprinting, injection molding and so on.

• 한국정보통신학회논문지
• /
• 제2권1호
• /
• pp.71-77
• /
• 1998

본 논문에서는 LMS와 CMA 알고리즘에 의한 적응 배열안테나의 training 원리와 제어방법을 기술하고 수렴특성, 지향성 패턴의 적응성, SINR 및 신호파의 재현 특성을 비교 분석한다. LMS와 CMA 적응 안테나 원리를 적용한 선형 $\lambda$/4 간격 4소자 배열안테나에 $\pi$/4 QPSK 신호파를 인가했을때 정상상태에서 SINR가 각각 13.8［dB］와 12.8［dB］로써 CMA에 비하여 LMS가 우수한 SINR와 빠른 수렴특성을 보였으며 간섭파의 방향에 적응하여 강한 영점을 잘 형성하는 것으로 나타났다.

• 한국철도학회논문집
• /
• 제11권6호
• /
• pp.524-529
• /
• 2008

도시철도 차륜에서 손상된 차륜은 주행 중의 승차감 악화 및 보수비용의 증가로 이어질 수 있기 때문에 차륜답면 특성 변화에 대한 평가는 대단히 중요하다. 본 연구에서는 비파괴적 표면검사법을 이용하여 차륜답면의 손상 평가를 실시하였으며 접촉위치, 주행거리, 제동방식에 따라 차륜답면의 특성을 평가하였다. 그 결과 접촉위치에 따라 차륜답면이 현저히 다른 손상 특성을 나타남을 보여주고 있다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.137.1-137
• /
• 2003

A pepper strain of Cucumber mosaic virus (Pf-CMV) induces a mild chlorotic spot symptom in zucchini squash at 9 days post-inoculation (dpi), wile Fny strain of CMV causes severe mosaic and stunting symptom at 4 dpi in this host. Pseudorecombinants were constructed between the two strains, and assessments of symptom severity were indicated that both RNA2 and RNA3 were responsible for both mildness and the slow appearance of symptom elicited by Pf-CMV in zucchini squash. With various RNA2 and RNA3 chimeras between two strains of CMV, the genetic symptom determinants of phenotype of Pf-CMV were mapped to Tyr residue at positions amino acid 267 in 2a protein and at positions amino acid 168 in 3a movement protein (MP). Chimeras changed the sequences (both changed Tyr to lie) in the codons of both amino acid 168 of 3a MP and amino acid 267 of 2a protein were resulted in the high RNA accumulation, severity of symptom, and the rapid systemic spread, suggesting that 2a replicase as well as MP is involved in virus movement. The RNA accumulation pattern of all pseudorecombinants and chimeras are identical in protoplast of zucchini squash, indicating the virus movement is responsible for the phenotypes of two CMV strains rather than virus replication.

• Journal of Microbiology and Biotechnology
• /
• 제31권7호
• /
• pp.942-948
• /
• 2021

Canine influenza virus (CIV) induces acute respiratory disease in dogs. In this study, we aimed to determine the signaling pathways leading to the induction of IFN-β in a canine respiratory epithelial cell line (KU-CBE) infected with the H3N2 subtype of CIV. Small interfering RNAs (siRNAs) specific to pattern recognition receptors (PRRs) and transcription factors were used to block the IFN-β induction signals in H3N2 CIV-infected KU-CBE cells. Among the PRRs, only the TLR3 and RIG-I expression levels significantly (p < 0.001) increased in CIV-infected cells. Following transfection with siRNA specific to TLR3 (siTLR3) or RIG-I (siRIG-I), the mRNA expression levels of IFN-β significantly (p < 0.001) decreased, and the protein expression of IFN-β also decreased in infected cells. In addition, co-transfection with both siTLR3 and siRIG-I significantly reduced IRF3 (p < 0.001) and IFN-β (p < 0.001) mRNA levels. Moreover, the protein concentration of IFN-β was significantly (p < 0.01) lower in cells co-transfected with both siTLR3 and siRIG-I than in cells transfected with either siTLR3 or siRIG-I alone. Also, the antiviral protein MX1 was only expressed in KU-CBE cells infected with CIV or treated with IFN-β or IFN-α. Thus, we speculate that IFN-β further induces MX1 expression, which might suppress CIV replication. Taken together, these data indicate that TLR3 and RIG-I synergistically induce IFN-β expression via the activation of IRF3, and the produced IFN-β further induces the production of MX1, which would suppress CIV replication in CIV-infected cells.

• 생명과학회지
• /
• 제7권4호
• /
• pp.392-401
• /
• 1997

폴리오바이러스는 바이러스들 중에서도 특히 커기가 작은 바이러스로서 피막(coat)을 둘러싸는 막(envelop) 이 없다. 폴리오바이러스는 (+) 가닥의 단일 RNA 게놈을 갖는데 이는 한 개의 해독판 (open reading frame)을 이용하여 다단백전구체를 만든 후 바이러스 자체의 단백질분해효소에 의해 스스로 잘라져서 궁극적으로느 특이한 기능을 갖는 여러개의 단백질이 된다. P1 다단백질전구체로부터 만들어지는 단백질들은 바이러스의 피막을 구성하는 성분이다. 단백질분해효소인 2A에 의한 최초의 절단은 구조단백질 P1 전구체와 구조단백질이 아닌 P2-P3간을 분리시켜준다. 단백질분해효소 2A는 진핵세포 판독개시인자(translation initiation factor) 4F의 한 subunit인 숙주단백질 p220의 절단에 간접으로 참여한다. 이 단백질의 절단은 캡(cap)에 의존하는 숙주세포의 대부분의 판독을 차단하게 되며 이는 판독에 사용되는 숙주세포의 모든 기구들을 캡에 의존하지 않는 폴리오바이러스 NA 특유의 판독을 위해 전적으로 사용할 수 있게 해준다. 2B, 2C, 2BC 단백질의 기능에 대해서는 많이 알려져 있지 않다. 2B, 2C, 2BC와 3CD 단백질들은 바이러스로 인해 만들어지는 소낭(vesicle)의 복제복합체에 함유되어 있으므로 바이러스의 RNA 복제시 중요한 역할을 함을 암시해준다. 새로이 만들어진 모든 바이러스 RNA는 VPg와 공유결합으로 연결되어 있다. VPg는 3AB로부터 만들어진 아미노산 22개 짜리의 폴리펩타이드이다. 3C와 3CD는 단백질분해소로 다단백질 전구체의 대부분의 절단부위를 잘라준다. 3C단백질은 숙주의 전사인자를 불활성화 시킴으로써 RNA polymer II와 III에 의한 전사를 저해한다. 3D는 RNA의존선RNA 중합효소이다. 폴리오바이러스는 (+)가닥 RNA 바이러스의 일반적인 복제양식을 따른다. 즉 (+) 가닥 RNA는 이와 상보적인 (-)가닥 RNA로 전사되고 이는 다시 (+)가닥 RNA의 합성을 위한 주형으로 사용된다. 폴리오바이러스의 RNA 합성은 세포내막에서 일어나는 데 RNA 복제에 요구되는 주형 RNA와 이때 필요한 단백질들이 어떤 방법으로 세포내막에서 모일 수 있는지는 아직 밝혀진 것이 적다. 바이러스입자의 형성은 세포막의 RNA 복제가 들어가는 데 피막단백질이 (+)가닥 RNA을 인식하는 표지 즉 packaging singal에 대해서는 거의 알려져 있지 않다. 폴리오바이러스 감염 후 첫 바이러스입자가 만들어지기 까는 약 6시간이 소요된다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• pp.45-52
• /
• 2009

The research on miniature devices based on non-silicon materials, in particular polymeric materials has been attracting more and more attention in the research field of the micro/nano fabrication in recent years. Lost of applications and many literatures have been reported. However, the study on the micro thermal imprint process of glassy polymer is still not systematic and inadequate. The aim of this research I to obtain a numerical material model for an amorphous glassy polymer, polycarbonate (PC), which can be used in finite element analysis (FEA) of the micro thermal imprint process near the glass transition temperature (Tg). An understanding of the deformation behavior of the PC specimens was acquired by performing tensile stress relaxation tests. The viscoelastic material model based on generalized Maxwell model was introduced for the material near Tg to establish the FE model based on the commercial FEA code ABAQUS/Standard with a suitable set of parameters obtained for this material model form the test data. As a result, the feasibility of the established viscoelastic model for PC near Tg was confirmed and this material model can be used in FE analysis for the prediction and improvement of the micro thermal imprint process for pattern replication.

• Molecules and Cells
• /
• 제23권1호
• /
• pp.80-87
• /
• 2007

Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV), members of curtoviruses, encode seven open reading frames (ORFs) within a ~3 kb genome. One of these viral ORFs, C1, is known to play an important role in the early stage of viral infection in plants during initiation of viral DNA replication. We used promoter:: reporter (${\beta}$-glucuronidase) gene fusions in transgenic Arabidopsis to identify the putative promoter region of BCTV ORF C1. Unlike other geminiviruses, the intergenic region of BCTV was not sufficient to promote C1 expression in transgenic plants. When sequences extending into the coding region of C1 were tested, strong expression of the reporter protein was observed in vascular tissues of transgenic plants. This expression was not dependent on the presence of the intergenic regions or proximal 5' portions of the C1 coding region. Transgenic plants expressing a reporter gene under control of the putative complete C1 promoter were inoculated with virus to determine if any viral transcript affected C1 expression. Virus inoculated plants did not show any altered pattern or change in of reporter gene expression level. These results suggest that (1) important transcriptional activator elements for C1 expression reside in the 3' portion of C1 coding area itself, (2) C1 protein does not auto-regulate its own expression and (3) C1 expression of two curtoviruses is controlled differently compared to other geminiviruses.

• 소성∙가공
• /
• 제22권1호
• /
• pp.23-29
• /
• 2013

In this study, a micro/nano-random-pattern-structure surface was machined by electric discharge machining (EDM) followed by replicating the EDM surface with a silicone elastomer having low energy and greater hydrophobicity. The variation of hydrophobicity was of prime interest and was examined as a function of the surface roughness of the replicated silicone elastomer. The hydrophobicity was evaluated by the water contact angle (WCA) measured on the relevant surface. For the experiments, the original surfaces were machined by die sinking electric discharge machining (DS-EDM) and wire cutting electric discharge machining (WC-EDM). The ranges of surface roughness were Ra $0.8{\sim}19{\mu}m$ for the DS-EDM and Ra $0.5{\sim}4.7{\mu}m$ for the WC-EDM. In order to fabricate a hydrophobic surface, the EDM surfaces were directly replicated using a liquid-state silicone elastomer, which was thermally cured. The measured WCA on the replicated surfaces for DS-EDM was in the range of $115{\sim}130^{\circ}$ and for WC-EDM the WCA was in the range of $123{\sim}150^{\circ}$. Additionally, the dynamic hydrophobicity was evaluated by measuring an advancing and a receding WCA on the replicated silicone elastomer surfaces.