• 한국음향학회지
• /
• 제25권6호
• /
• pp.282-290
• /
• 2006

본 논문에서는 1.2 kbps 의 전송률을 가지는 초 저속 음성 부호화기를 위한 방법과 구조를 제안한다. ZFE-CELP (Zinc Function Excitation-Code Excited Linear Prediction) 음성 부호화기는 선형예측 분석 후, 추출된 잔여 신호가 유성음일 경우 Zinc Function을 이용하여 부호화하고, 무성음일 경우에는 CELP 구조를 이용하여 부호화한다. 또한 Super-frame (40ms) 의 영향으로 발생하는 하모닉의 불연속 문제를 해결하기 위해 오버 샘플링을 이용한 선형 위상 합성 기법을 이용하고 Zinc 함수의 정확한 표준파형을 추출하기 위하여 분석-합성 구조를 제안한다. 제안된 초 저속음성 부호화기의 성능을 2.4 kbps의 MELP (Multi Pulse Linear Prediction) 부호화기 및 1.9kbps의 ZFE-PWI (Zinc Function Excitation-Prototype Waveform Interpolation) 음성 부호화기와 비교하였다 제안된 부호화 방법은 19kbps ZFE-PWI 부호화기와 유사한 성능을 보이는 것을 확인하였다.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2015년도 춘계학술대회 및 임시총회
• /
• pp.61-61
• /
• 2015

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice - M. oryzae pathosystem has become a model in the study of plant - fungal interactions due to its economic importance and accumulating knowledge. During the evolutionary arms race with M. oryzae, rice plants evolved a repertoire of Resistance (R) genes to protect themselves from diseases in a gene-for-gene fashion. M. oryzae secretes a battery of small effector proteins to manipulate host functions for its successful infection, and some of them are recognized by host R proteins as avirulence effectors (AVR), which turns on strong immunity. Therefore, the analysis of interactions between AVRs and their cognate R proteins provide crucial insights into the molecular basis of plant - fungal interactions. Rice blast resistance genes Pik, Pia, Pii comprise pairs of protein-coding ORFs, Pik-1 and Pik-2, RGA4 and RGA5, Pii-1 and Pii-2, respectively. In all three cases, the paired genes are tightly linked and oriented to the opposite directions. In the AVR-Pik/Pik interaction, it has been unraveled that AVR-Pik binds to the N-terminal coiled-coil domain of Pik-1. RGA4 and RGA5 are necessary and sufficient to mediate Pia resistance and recognize the M. oryzae effectors AVR-Pia and AVR1-CO39. A domain at the C-terminus of RGA5 characterized by a heavy metal associated domain was identified as the AVR-binding domain of RGA5. Similarly, physical interactions among Pii-1, Pii-2 and AVR-Pii are being analyzed.

• Molecular & Cellular Toxicology
• /
• 제4권2호
• /
• pp.113-123
• /
• 2008

Microglia, which is the primary immune effector cells in the central nervous system, constitutes the first line of defense against infection and injury in the brain. The goal of this study was to determine the protective (anti-inflammation) mechanisms of forsythia suspense (FS) on LPS-induced activation of BV-2 microglial cells. The effects of FS on gene expression profiles in activated BV-2 microglial cells were evaluated using microarray analysis. BV-2 microglial cells were cultured in a 100mm dish $(1{\times}10^7/dish)$ for 24hr and then pretreated with $1{\mu}g/mL$ FS or left untreated for 30 min. Next, $1{\mu}g/mL$ LPS was added to the samples and the cells were reincubated at $37^{\circ}C$ for 30 min, 1hr, and 3hr. The gene expression profiles of the BV-2 microglial cells varied depending on the FS. The oligonucleotide microarray analysis revealed that MAPK pathway-related genes such as Mitogen activated protein kinase 1 (Mapk1), RAS protein activator like 2 (Rasal2), and G-protein coupled receptor 12 (Gpr12) and nitric oxide biosynthesis-related genes such as nitric oxide synthase 1 (neuronal) adaptor protein (Nos1ap), and dimethylarginine dimethylaminohydrolase 1 (Ddah1) were down regulated in FS-treated BV-2 microglial cells. FS can affect the MAPK pathway and nitric oxide biosynthesis in BV-2 microglial cells.

• 동의생리병리학회지
• /
• 제17권3호
• /
• pp.819-825
• /
• 2003

pharbitis nil and Taraxacum mongolicum are representative herbs that have been used for cancer treatment in Korean traditional medicine. To understand the molecular basis of the antitumor function, we analyzed the effect of these herbs on proliferation and apoptosis of tumor cells using a gastric cancer cell line AGS. Cell counting assay showed that pharbitis nil strongly inhibit cell proliferation Of AGS whereas Taraxacum mongolicum exhibit no detectable effect on cellular growth. [³H]thymidine uptake analysis also demonstrated that DNA replication of AGS is suppressed in a dose-dependent manner by treatment with pharbitis nil. Additionally, tryphan blue exclusion assay showed that Pharbitis nil induce apoptotic cell death of AGS in a dose-dependent. To explore whether anti antiproliferative and/or proapototic property of Pharbitis nil is associated with their effect on gene expression, we performed RT-PCR analysis of cell cycle- and apoptosis-related genes. Interestingly, mRNA expression levels of c-Jun, c-Fos, c-Myc, and Cyclin D1 were markedly reduced by Pharbitis nil. Taraxacum mongolicum also showed inhibitory action on expression of these growth-promoting protooncogene but there effects are less significant, as compared to Pharbitis nil. Furthermore, it was also found that Pharbitis nil activates expression of the p53 tumor suppressor and its downstream effector p21Waf1, which induce G1 cell cycle arrest and apoptosis. Collectively, our data demonstrate that Pharbitis nil induce growth inhibition and apoptosis of human gastric cancer cells and these effects are accompanied with down-and up-regulation of growth-regulating protooncogenes and tumor suppressor genes, respectively. This observation thus suggests that the anticancer effect of Pharbitis nil might be associated with its regulatory capability of tumor-related gene expression.

• Journal of Microbiology
• /
• 제37권4호
• /
• pp.256-262
• /
• 1999

Latent membrane protein 1 (LMP1) of the Epstein-Barr virus (EBV) is an integral membrane protein with six transmembrane domains, which is essential for EBV-induced B cell transformation. LMP1 functions as a constitutively active tumor necrosis factor receptor (TNFR) like membrane receptor, whose signaling requires recruitment of TNFR-associated factors (TRAFs) and leads to NF-${\kappa}B$ activation. NF-${\kappa}B$ activation by LMP1 is critical for B cell transformation and has been linked to many phenotypic changes associated with EBV-induced B cell transformation. Deletion analysis has identified two NF-${\kappa}B$ activation regions in the carboxy terminal cytoplasmic domains of LMP1, termed CTAR1 (residues 194-232) and CTAR2 (351-386). The membrane proximal C-terminal domain was precisely mapped to a PXQXT motif (residues 204-208) involved in TRAF binding as well as NF-${\kappa}B$ activation. In this study, we dissected the CTAR2 region, which is the major NF-${\kappa}B$ signaling effector of LMP1, to determine a minimal functional sequence. A series of LMP1 mutant constructs systematically deleted for the CTAR2 region were prepared, and NF-${\kappa}B$ activation activity of these mutants were assessed by transiently expressing them in 293 cells and Jurkat T cells. The NF-${\kappa}B$ activation domain of CTAR2 appears to reside in a stretch of 6 amino acids (residues 379-384) at the end of the carboxy terminus.

• Journal of Korea Trade
• /
• 제25권1호
• /
• pp.47-64
• /
• 2021

Purpose - This paper empirically analyzed the determinants of the online food market in Korea and Vietnam as representatives of the developed market and emerging market. The online food market can be regarded as having a high potential value. This study aims to suggest the appropriate implications for each developed market and emerging market by empirically comparing and analyzing customers' online food purchase determinants in the growth change of the online food market. Design/methodology - The empirical model of this study was established with the motif of the TAM+Trust model suggested by Nguyen et al.'s (2019) existing theoretical framework. Davis's (1989) TAM model was adopted to establish a framework related to the determinants that consumers would accept, for the online food purchasing method. Then, the trust variable is added to the framework which is regarded as an important effector especially in food related researches. In this study's comparative analysis, the multi-group structural equation modeling analysis was implemented. Findings - The main finding of this study can be summarized as that the moderating effect of nationality is significant. This means that there is an obvious difference between the developed online food market and the emerging online food market. In addition, as the growth of the online market changes, the significant determinants of consumers' attitudes and purchase intentions are somewhat different. However, the usefulness of online food purchasing methods and the trust of websites were analyzed as significant factors. Originality/value - Although the potential of the online food market is abundant, studies on the determinants of customer's attitude and purchase intention are insufficient. Moreover, comparative studies between countries have not been conducted in existing studies. Therefore, the research value of this paper can be explained in that it has suggested implications for the continued growth of the online food market.

• Food Science and Biotechnology
• /
• 제15권5호
• /
• pp.694-697
• /
• 2006

The initiation of immunoglobulin E (IgE)-mediated allergic reactions requires binding of IgE antibody to its high-affinity receptor. Human basophilic KU812F cells express $Fc{\varepsilon}RI$ on the cell surface and act as effector cells in the allergic response. In this study, we investigated the effects of Scutellaria radix extract on the expression of the $Fc{\varepsilon}RI$ in human KU812F cells. Flow cytometric analysis showed that S. radix extract treatment caused a concentration-dependent decrease in $Fc{\varepsilon}RI$ expression on the cell surface. Furthermore, the level of $Fc{\varepsilon}RI$ ${\alpha}$, ${\beta}$, and ${\gamma}$ chain mRNA in KU812F cells was examined by RT-PCR. S. radix extract reduced total cellular $Fc{\varepsilon}RI$ $\alpha$ and ${\gamma}$ chain mRNA expression in a concentration-dependent manner. $Fc{\varepsilon}RI$-mediated histamine release was reduced from $21.75{\pm}1.34\;ng/10^6$ cells in non-treated cells to $16.46{\pm}1.98\;ng/10^6$ cells in S. radix extract treated cells. These results suggested that S. radix extract has the potential to down-regulate of FcRI expression and to inactivate basophils.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.81.2-82
• /
• 2003

Plants have evolved along with pathogens, and they have developed sophisticated defense systems against specific microorganisms to survive. G-protons are considered one of the upstream signaling components working as a key for the defense signal transduction pathway. For activation and inactivation of G-protein, GTP-biding proteins are involved. GTP -binding proteins are found in all organisms. Small GTP-binding proteins, having masses of 21 to 30kD, belong to a superfamily, often named the Ras supefamily because the founding members are encoded by human Ras genes initially discovered as cellular homologs of the viral ras oncogene. Members of this supefamily share several common structural features, including several guanine nucleotide binding domains and an effector binding domain. However, exhibiting a remarkable diversity in both structure and function. They are important molecular switches that cycle between the GDP-bound inactive form into the GTP-bound active form through GDP/GTP replacement. In addition, most GTP-binding proteins cycle between membrane-bound and cytosolic forms. such as the RAC family are cytosolic signal transduction proteins that often are involved in processing of extracellular stimuli. Plant RAC proteins are implicated in regulation of plant cell architecture secondary wall formation, meristem signaling, and defense against pathogens. But their molecular mechanisms and functions are not well known. We isolated a RacB homolog from rice to study its role of defense against pathogens. We introduced the constitutively active and the dominant negative forms of the GTP-hinging protein OsRacB into the wild type rice. The dominant negative foms are using two forms (full-sequence and specific RNA interference with RacB). Employing southern, and protein analysis, we examine to different things between the wild type and the transformed plant. And analyzing biolistic bombardment of onion epidermal cell with GFP-RacB fusion protein revealed association with the nucle.

• Journal of Periodontal and Implant Science
• /
• 제30권3호
• /
• pp.675-687
• /
• 2000

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T and B lymppocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate immunomodulatory effect of exposure to Fusobacterium nucleatum(F. nucleatum) prior to Porphyromonas gingivalis(P. gingi - valis). Group 1(control) mice were immunized with phosphate-buffered saline, Group 2 were immunized with F. nucleatum prior to P. gingivalis, while Group 3 were immunized P. gingivalis alone. All the T cell clones derived from Group 2 demonstrated type 2 helper T cell clone(Th2 subsets), while those from Group 3 mice demonstrated Th1 subsets. Exposure of mice to F . nucleatum prior to P. gingivalis interfered with opsonophagocytosis function of sera against P. gingivalis. In adoptive T cell transfer experiments, in vivo protective capacity type 2 helper T cell clones(Th2) from Group 2 was significantly lower than type 1 helper T cell clones(Th1) from Group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated the different pattern of recognition of P .gingivalis fimbrial proteins between sera from Group 2 and Group 3. In conclusion, these study suggest that colonization of the subgingival niche by F .nucleatum prior to the periodontal pathogen, P. gingivalis, modulates the host immune responses to P. gingivalis at humoral, cellular and molecular levels.

• 동의생리병리학회지
• /
• 제18권6호
• /
• pp.1843-1849
• /
• 2004

Conventional medicines have usually sorted to a number of treatments such asoperation, radiotherapy, and chemotherapy. The existing anti-cancer agents, designed to eradicate cancer cells, have strong toxicities, also with leading to harmful side effects. Recently, a number of researches on natural products have been actively carried out in efforts to develop new treatments that can decrease side effects or increase anti-cancer effects. We performed this study to understand the molecular basis underlying the antitumor effects of Pharbitis nil, and Plantago asiatica, which have been used for herbal medicinal treatments against cancers in East Asia. We analyzed the effects of these medicinal herbs on proliferation and on expression of cell growth/apoptosis related molecules, with using an AGS gastric cancer cell line. The treatment of Pharbitis nil dramatically reduced cell viabilities in a dose and time-dependent manner, but Plantago asiatica didn't. FACS analysis and Annexin V staining assay also showed that Pharbitis nil induce apoptotic cell death of AGS. Expression analyses via RT-PCR and Western blots revealed that Pharbitis nil didn't increase expression of the p53 and its downstream effector p21/sup wafl/, and that the both increased expression of apoptosis related Sax and cleavage of active caspase-3 protein. We also confirmed the translocation of Sax to mitochondria. Collectively, our data demonstrate that Pharbitis nilinduce growth inhibition and apoptosis of human gastric cancer cells, and these effects are correlated with down- and up-regulation of growth-regulating apoptotic and tumor suppressor genes, respectively.