• IMMUNE NETWORK
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• 제22권3호
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• pp.23.1-23.12
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• 2022

Natural infection with severe acute respiratory syndrome-coronavirus-2 or vaccination induces virus-specific immunity protecting hosts from infection and severe disease. While the infection-preventing immunity gradually declines, the severity-reducing immunity is relatively well preserved. Here, based on the different longevity of these distinct immunities, we develop a mathematical model to estimate courses of endemic transition of coronavirus disease 2019 (COVID-19). Our analysis demonstrates that high viral transmission unexpectedly reduces the rates of progression to severe COVID-19 during the course of endemic transition despite increased numbers of infection cases. Our study also shows that high viral transmission amongst populations with high vaccination coverages paradoxically accelerates the endemic transition of COVID-19 with reduced numbers of severe cases. These results provide critical insights for driving public health policies in the era of 'living with COVID-19.'

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1573-1579
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• 2018

Transcriptional gene silencing is regulated by the chromatin structure, which is by various factors including histones. Saccharomyces cerevisiae contains transcriptionally silenced regions such as telomeric regions and hidden mating (HM) loci. The positively-charged amino acids on the histone H4 tail were reported to be critical for the telomeric silencing in yeast, by interacting with Dot1, a specific methyltransferase for the $79^{th}$ lysine on histone H3. However, Dot1 did not affect gene silencing within HM loci, but whether the positively-charged amino acids on the H4 tail affect HM silencing has not been defined. To elucidate the function of the H4 tail on HM silencing, we created several MATa-type yeast strains bearing the substitution of arginine with alanine or lysine on the histone H4 tail and checked the sensitivity of MATa-type yeast to alpha pheromone. The arginine point mutants substituted by alanine (R17A, R19A, and R23A) did not show sensitivity to alpha pheromone, but only two arginine mutants substituted by lysine (R17K and R19K) restored the sensitivity to alpha pheromone-like wild type. These data suggested that the basic property of arginine at $17^{th}$ and $19^{th}$ positions in the histone H4 tail is critical for maintaining HM silencing, but that of the $23^{rd}$ arginine is not. Our data implicated that the positive charge of two arginine residues on the histone H4 tail is required for HM silencing in a manner independent of Dot1.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.581-582
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• 2010

광 의료 분야 중 저출력레이저 치료에 사용되는 레이저와 같은 특정 파장을 발생하고 레이저보다 안정적으로 사용이 가능한 고휘도 LED를 조사하여 광 의료 분야에 적용할 수 있는 시스템을 개발하였다. 광조사 시스템은 마이크로 컨트롤러, FPGA, TLC5941 및 고휘도 LED를 이용하여 설계 및 제작하였으며 광조사 시간, 강도, 주기 등 세포 증식에 영향을 칠 수 있는 다양한 변수들의 제어가 가능하도록 하였다. 또한 세포 배양에 사용되는 인큐베이터 내부의 조사가 용이하도록 탈부착이 가능한 모듈화 된 LED를 설계 제작하여 세포 증식에서 발생 가능한 생물학적 변수를 최소화하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.572-573
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• 2010

단색성, 지향성 및 고휘도의 특성을 가지는 레이저는 광의료 분야에 적용되어 다양한 치료 분야에 사용되고 있다. 그 중 특정 파장의 빛이 세포를 자극하여 활성화 시키는 효과가 밝혀지며 레이저를 이용한 치료법이 각광 받기 시작했다. 하지만 기존에 사용되는 저출력 레이저는 매우 고가이며 사용이 어려운 단점을 가지고 있다. 본 연구에서는 다양한 파장 및 출력의 발생이 가능한 반도체 레이저를 이용하여 세포 활성 및 증식이 가능하도록 레이저 다이오드 조사기를 개발하고 이를 사용하여 세포 활성에 미치는 영향을 확인하였다.

• 대한의생명과학회지
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• 제16권1호
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• pp.68-70
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• 2010

Puer tea is a traditional beverage originating from Yunnam area of China. It supplies basic nutrients such as vitamin C. It has been well reported that daily drinking of Puer tea can help the digestion and ease the stomachache after food intake. Puer tea also contains various polyphenols which may exert antibacterial activity against Staphylococcus aureus and Listeria monocytogenes. Because of these functional effects on digestive system we suspected if Puer tea can display any dietary effect or decrease the obesity after long-term drinking. We employed 6-week old SD rats as experimental animal and treated them with extract of Puer tea in relation to the body weights. Rats were divided into 5 groups (NC, PC, E, E+P, E+P5). NC group was experimental control and rest of them are as follows: water only (PC), water with exercise (E), water with exercise and Puer tea extract (E+P), water with exercise and 5X extract of Puer tea (E+P5). Feeding was carried out every day for 5 weeks by oral administration. Reduction rate of body weights was highest in E group. Relative ratio of losing weight was as follows: PC group (100.78%), E group (95.57%), E+P group (94.53%) and E+P5 group (74.22%), respectively. Exercise was more helpful to control the body weight. The result strongly suggests that Puer tea is highly effective to control the body weight and could be used for pharmaceutical purpose to treat obesity without side effects.

• 대한의생명과학회지
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• 제10권2호
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• pp.143-151
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• 2004

Matrix metalloproteinases (MMPs) are capable of degrading extracellular matrix, a process that is necessary for angiogenesis, tumor invasion and metastasis. Platelet-activating factor (PAP) increases angiogenesis, tumor growth and metastasis through nuclear factor (NF)-$\kappa$B activation. Based on these facts, the involvement of MMPs in PAF-induced pulmonary metastasis was investigated in murine sarcoma cells, MMSV-BALB/3T3. Messenger RNA expression and enzymatic activity of MMP-9 were assessed by RT-PCR and zymography, and cell migration and metastasis were done for the detection of MMP-9 functional activity. PAP induced mRNA expression and enzymatic activity of MMP-9, and its effects were either inhibited by the PAP antagonist, WEB 2170 or by the NF-$\kappa$B inhibitor, parthenolide, or p65 antisense oligonucleotide in a dose-dependent manner. In addition, PAF induced promoter activity of MMP-9, which was inhibited by WEB 2170, phenanthroline, NAC, PDTC. These results indicate that PAF induces mRNA expression and enzymatic activity of MMP-9 in NF-$\kappa$B dependent manner. Cell migration assay showed that PAF induced MMSV-BALB/3T3 migration, and its effect was significantly inhibited by treatment with phenanthroline. PAF enhanced pulmonary metastasis of murine sarcoma cells, MMSV-BALB/3T3 was also reduced by phenanthroline. These results suggest that PAF-enhanced cell migration and pulmonary metastasis is mediated through the expression of MMP. In conclusion, It is suggested that PAF enhances pulmonary metastasis by inducing MMP-9 expression via the activation of NF-$\kappa$B.

• 대한의생명과학회지
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• 제3권2호
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• pp.71-76
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• 1997

실험적 자궁암 치료제로서 본 연구소에서 합성한 마이토센유사체를 인체 자궁암세포주인 SiHa, C33A, HeLa, CaSki에 처리하여, 체외 항암활성 측정시 합성 마이토센유사체들은 이 들 세포주에 대하여 대조 항암제들에 비하여 의의있는 세포독성을 보였으며, SiHa 세포주를 이용한 종양클론형성 억제검사에서는 22번 화합물만이 종양성장 억제활성이 가장 우수하였고 다른 화합물들은 대조항암제들에 비하여 활성이 낮았다. 이 마이토센유사체들에 대한 체외 항암감수성결과는 향후 전임상적인 자궁경부암 화합요법제의 기초자료로 유용할것으로 생각된다.

• 한국자기공명학회논문지
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• 제24권1호
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• pp.1-8
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• 2020

An extracellular matrix protein, transforming growth factor-beta-induced protein (TGFBIp/βig-h3), which is induced by transforming growth factor-β in the human cornea, skin, and matrix of many connective tissues, is associated with the adhesion, migration, proliferation, and differentiation of various cells. TGFBIp contains four homologous repeat domains, known as FAS1 domains, where certain mutations have been considered to cause corneal dystrophies. In this study, backbone NMR assignments of FAS1-3/FAS1-4 tandem domain were obtained and compared with those previously known for the isolated FAS1-4 domain. The results corroborate in solution the inter-domain interaction between FAS1-3 and FAS1-4 in TGFBIp.

• 대한의생명과학회지
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• 제25권1호
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• pp.83-91
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• 2019

This study was undertaken to investigate the therapeutic effect of Angelica acutiloba on allergic dermatitis, which Angelica acutiloba is traditionally known to have antiinflammatory effects. Sprague-Dawley (SD) rats were divided into five groups: normal control group, experimental allergic dermatitis group (vehicle group), low dose of Angelica acutiloba extract (low-dose group), high dose of Angelica acutiloba extract (high-dose group), and antihistamine treated group with experimental dermatitis (antihistamine group). Total leukocyte, neutrophil, lymphocyte, monocyte and eosinophil counts were significantly higher in the vehicle group than in the control group, but these variables were significantly lower in the low- and high-dose groups than in the vehicle group. The platelet/lymphocyte ratio in the red blood cell index was significantly lower in the low- and high-dose groups than in the vehicle group. Low and high doses of the Angelica acutiloba extract did not have toxic effects on liver and kidney. Serum NO, iNOS and levels were highest in the vehicle group but significantly lower in the low- and high-dose groups, especially in the high-dose group. The results of this study suggested that the Angelica acutiloba extract had the effect of alleviating or treating the experimental allergic dermatitis, and it was concluded that the high dose was more effective.

• 한국식생활문화학회지
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• 제36권5호
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• pp.430-440
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• 2021

The purpose of this study was to provide basic data for future research and suggest product development and market segmentation strategies by identifying the perceptions and consumption behaviors of vegetarians in each segment of the vegetarian market. According to food consumption value, a total of three market segments were derived, and the markets were named based on their characteristics, including 'environment and animal protection', 'multiple consideration' and 'low interest'. As a result of analyzing the perception of vegetarian-based food, "environment and animal protection" and "multiple consideration" presented positive perceptions of a vegetarian food product. Conversely, the group stating low interest expressed negative perceptions of the vegetarian food product. An analysis of the requirements for development for vegetarian-based foods products (eg. aquafaba), indicated that the development requirements for all products, except cultured and processed meats, were high.?Considerable demand was observed for vegetarian menus and vegetarian restaurants. As a result of the analysis on the necessity of the elements of the vegetarian restaurant menu, the subjects that stated "multiple consideration" had significantly higher awareness of issues related to vegetarian foods than others.