• IMMUNE NETWORK
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• v.22 no.3
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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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• v.28 no.9
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.581-582
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• 2010

This paper performed the basic study for developing the Photodynamic Therapy Equipment for medical treatment. We developed the equipment palpating cell proliferation using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 30 step by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and Pulse Width Modulation(PWM), and the output of a high brightness LED could be controlled stage by stage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.572-573
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• 2010

This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The equipment was fabricated using the 655nm laser diode and microcontroller unit and designed to enable us to control light irradiation time, and reservation.. In case of cell proliferation experiment, each experiment was performed to irradiation group and non-irradiation group for bome marrow cell. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring.

• Biomedical Science Letters
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• v.16 no.1
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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.

• Biomedical Science Letters
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• v.10 no.2
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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.

• Biomedical Science Letters
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• v.3 no.2
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• pp.71-76
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• 1997

To develop a promising alkylating agents for anti-cervical cancer chemotherapy, five mitosene analogues were synthesized. Despite the potentiality of better cytotoxicity on solid tumor cells as opposed to that on rapidly-doubled leukemic cells, there have been no reports on the inhibition of the cervical cancer cell line by mitosene analogues. The present experiment was designed to investigate whether mitosene analogues can effectively inhibit the cellular proliferation of cervical cancer cells by using an in vitro chemosensitivty system. The mitosene analogues displayed a potent cytotoxic effect on the tested cervical cancer cell lines. Among the analogues, (22) compound gave the best inhibitory effect on SiHa tumor colonies formation. These data indicate that mitosene analogues can effectively inhibit the growth of cervical cancer cells in vitro.

• Journal of the Korean Magnetic Resonance Society
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• v.24 no.1
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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.

• Biomedical Science Letters
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• v.25 no.1
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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.

• Journal of the Korean Society of Food Culture
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• v.36 no.5
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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.