• Journal of IKEEE
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• v.23 no.3
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• pp.904-909
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• 2019

Using the ion-beam irradiated indium zinc oxide (IZO) films which was cured at $100^{\circ}C$, uniform LC and homogeneous alignment of liquid crystal (LC) molecules was achieved. The IZO film was deposited on the glass substrate at the curing temperature of $100^{\circ}C$ and irradiated by the ion-beam which is an LC alignment method. To verify the LC alignment characteristics, polarizing optical microscope and the crystal rotation method were used. Additionally, it was confirmed that the LC cell with the IZO films had an enough thermal budget for high-quality LC applications. Field emission scanning electron microscope was conducted as a surface analysis to evaluate the effect of the ion-beam irradiation on the IZO films. Through this, it was revealed that the ion-beam irradiation induced rough surface with anisotropic characteristics. Finally, electro-optical (EO) performances of the twisted-nematic cells with the IZO films were collected and it was confirmed that this cell had better EO performances than the conventional rubbed polyimide. Furthermore, the polar anchoring energy was measured and a suitable value for stable LC device operation was achieved.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.489-499
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• 2019

Subunit vaccines are safer and more stable than live vaccines although they have the disadvantage of eliciting poor immune response. To develop a subunit vaccine, an effective delivery system targeting the key elements of the protective immune response is a prerequisite. In this study, oxidized carbon nanospheres (OCNs) were used as a subunit vaccine delivery system and tuberculosis (TB) was chosen as a model disease. TB is among the deadliest infectious diseases worldwide and an effective vaccine is urgently needed. The ability of OCNs to deliver recombinant Mycobacterium tuberculosis (Mtb) proteins, Ag85B and HspX, into bone marrow derived macrophages (BMDMs) and dendritic cells (BMDCs) was investigated. For immunization, OCNs were mixed with the two TB antigens as well as the adjuvant monophosphoryl lipid A (MPL). The protective efficacy was analyzed in vaccinated mice by aerosol Mtb challenge with a virulent strain of Mtb and the bacterial burdens were measured. The results showed that OCNs are highly effective in delivering Mtb proteins into the cytosol of BMDMs and BMDCs. Upon immunization, this vaccine formula induced robust Th1 immune response characterized by cytokine profiles from restimulated splenocytes and specific antibody titer. More importantly, enhanced cytotoxic $CD8^+$ T cell activation was observed. However, it did not reduce the bacteria burden in the lung and spleen from the aerosol Mtb challenge. Taken together, OCNs are highly effective in delivering subunit protein vaccine and induce robust Th1 and $CD8^+$ T cell response. This vaccine delivery system is suitable for application in settings where cell-mediated immune response is needed.

• Membrane Journal
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• v.30 no.6
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• pp.433-442
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• 2020

In this study, in order to build a molecular dynamics simulation model of ionomer for water electrolysis, an ionomer model that reflects the characteristics of a water electrolysis system in which excess water molecules exist was compared to an ionomer built according to the conventional simulation method of the fuel cells membrane. The final ionomer MD models have a strong phase separation and water channel that is one of the important characteristics of the perfluorinated ionomer, and are stable and water-insoluble under excessive water and high temperature conditions. In the ionomer MD models built in this study, the excess water molecules decrease an ion conductivity due to the dilution of ions, but increase a hydrogen diffusivity. Therefore, it is necessary to design the molecular structure of ionomers for water electrolysis in experimental studies as well as molecular dynamics studies according to the characteristics of the water electrolysis system reported in this study.

• BMB Reports
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• v.54 no.3
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• pp.164-169
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• 2021

Neuronal growth regulator 1 (NEGR1) is a GPI-anchored membrane protein that is involved in neural cell adhesion and communication. Multiple genome wide association studies have found that NEGR1 is a generic risk factor for multiple human diseases, including obesity, autism, and depression. Recently, we reported that Negr1-/- mice showed a highly increased fat mass and affective behavior. In the present study, we identified Na/K-ATPase, beta1-subunit (ATP1B1) as an NEGR1 binding partner by yeast two-hybrid screening. NEGR1 and ATP1B1 were found to form a relatively stable complex in cells, at least partially co-localizing in membrane lipid rafts. We found that NEGR1 binds with ATP1B1 at its C-terminus, away from the binding site for the alpha subunit, and may contribute to intercellular interactions. Collectively, we report ATP1B1 as a novel NEGR1-interacting protein, which may help deciphering molecular networks underlying NEGR1-associated human diseases.

• New & Renewable Energy
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• v.18 no.2
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• pp.40-49
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• 2022

In this study, the phase and electrochemical properties of Co and Ti substituted layered perovskites SmBaCo_2-xTi_xO_5+d (x=0.5, 0.7, 1.0, 1.1, 1.3, and 1.5) were analyzed, and their application as electrodes in solid oxide fuel cells (SOFCs) were evaluated. After calcination at 1300℃ for 6 h, a single phase was observed for two compositions of the SmBaCo_2-xTi_xO_5+d oxide system, SmBaCoTiO_5+d (x=1.0) and SmBaCo_0.9Ti_1.1O_5+d (x=1.1). However, the phases of SmBaCoTiO_5+d (SBCTO) and SmTiO₃ coexisted for compositions with x≥1.3 (Ti content). In contrast, for compositions of x≤0.7, the SmBaCo₂O_5+d phase was observed instead of the SmTiO₃ phase. To evaluate the applicability of these materials as SOFC electrodes, the electrical conductivities were measured under various atmospheres (air, N₂, and H₂). SBCTO exhibited stable semi-conductor electrical conductivity behavior in an air and N₂ atmosphere. However, SBCTO showed insulator behavior at temperatures above 600℃ in a H₂ atmosphere. Therefore, SBCTO may only be used as cathode materials. Moreover, SBCTO had an area specific resistance (ASR) value of 0.140 Ω·cm² at 750℃.

• Molecules and Cells
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• v.45 no.5
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• pp.329-342
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• 2022

The liver is the predominant metastatic site for pancreatic cancer. However, the factors that determine the liver metastasis and the specific molecular mechanisms are still unclear. In this study, we used human pancreatic cancer cell line Hs766T to establish Hs766T-L3, a subline of Hs766T with stable liver metastatic ability. We performed RNA sequencing of Hs766T-L3 and its parental cell line Hs766T, and revealed huge differences in gene expression patterns and pathway activation between these two cell lines. We correlated the difference in pathway activation with the expression of the four core transcriptional factors including STAT1, NR2F2, GATA2, and SMAD4. Using the TCGA database, we examined the relative expression of these transcription factors (TFs) in pan-cancer and their relationship with the prognosis of the pancreatic cancer. Among these TFs, we considered GATA2 is closely involved in tumor metastasis and may serve as a potential metastatic driver. Further in vitro and in vivo experiments confirmed that GATA2-mediated transcriptional activation of Notch3 promotes the liver metastasis of Hs766T-L3, and knockdown of either GATA2 or Notch3 reduces the metastatic ability of Hs766T-L3. Therefore, we claim that GATA2 may serve as a metastatic driver of pancreatic cancer and a potential therapeutic target to treat liver metastasis of pancreatic cancer.

• The Korea Journal of Herbology
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• v.33 no.5
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• pp.67-72
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• 2018

Objectives : Natural extracts have been extensively studied to replace single agent drugs that cause a variety of side effects. However, studies of changes to the formulation of natural extracts has not been nearly proceed. We aimed to investigate whether pharmacological stability of hyeonggaeyeongyotang gagambang (HYT) is altered by formulation changes for foaming tablet. Methods : In this study, we performed freeze - drying of HYT, which is known to have antioxidant and anti - inflammatory properties, and then changed the formulation by foaming. Results : As a result, the foaming reaction appeared normally when HYT foamed tablets were put into water, and almost all of the substances were dissolved in the aqueous solution. In addition, we confirmed using high-performance liquid chromatograph that the geniposide used as an indicator material of HYT was stable in most of the formulations. It was confirmed that the change of HYT formulation did not affect the antioxidant efficacy by the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, quantitative real-time PCR confirmed that the inhibitory effect of HYT on IL-$1{\beta}$ mRNA expression induced by lipopolysaccharides treatment in murine macrophage RAW 264.7 cells was similar in the solution of foaming tablet. Conclusions : These results suggest that the materials with various pharmacological effects can be stably maintained even when the formulation is changed by the foaming action of HYT. Our results are expected to provide important basic knowledge on formulation changes using various natural extracts.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1289-1295
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• 2023

Polyurethane foam insulation required for storing and transporting cryogenic liquefied gas is already widely used as a thermal insulation material for commercial LNG carriers and onshore due to its stable price and high insulation performance. These polyurethane foams are reported to have different mechanical performance depending on the density, and the density parameter is determined depending on the amount of the blowing agent. In this study, density-dependent polyurethane foam was fabricated by adjusting the amount of blowing agent. The mechanical properties of polyurethane foam were analyzed in the room temperature and cryogenic temperature range of -163℃ at 1.5 mm/min, which is a quasi-static load range, and the cells were observed through microstructure analysis. The characteristics of linear elasticity, plateau, and densification, which are quasi-static mechanical behaviors of polyurethane foam, were shown, and the correlation between density and mechanical properties in a cryogenic environment was confirmed. The correlation between mechanical behavior and cell size was also analyzed through SEM morphology analysis. Polyurethane foam with a density of 180 kg/m³ had a density about twice as high as that of a polyurethane foam with a density of 96 kg/m³, but yield strength was about 51% higher and cell size was about 9.5% smaller.

• Journal of Korean Society on Water Environment
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• v.40 no.3
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• pp.131-139
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• 2024

This study investigated the chemical properties of Organic Soil Amendments (OSAs) made from organic waste. It also assessed the effectiveness of using these OSAs in the soil layer of Green Infrastructure (GI) to reduce stormwater runoff and non-point source pollutants. The goal was to improve the national environmental value through resource recycling and contribute to the circular economy transformation and carbon neutrality of urban GI. The OSAs used in this study consisted of spent coffee grounds and food waste compost. They were found to be nutrient-rich and stable as artificial soils, indicating their potential use in the soil layer of GI facilities. Applying OSAs to bio-retention cells and permeable pavement resulted in a reduction of approximately 11-17% in stormwater runoff and a decrease of about 16-18% in Total Phosphorus (TP) discharge in the target area. Increasing the proportion of food waste compost in the OSAs had a positive impact on reducing stormwater runoff and pollutant emissions. This study highlights the importance of utilizing recycled resources and can serve as a foundation for future research, such as establishing parameters for assessing the effectiveness of GI facilities through experiments. To enable more accurate analysis, it is recommended to conduct studies that consider both the chemical and biological aspects of substance transfer in OSAs.

• IMMUNE NETWORK
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• v.23 no.6
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• pp.47.1-47.16
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• 2023

Scrub typhus, a mite-borne infectious disease, is caused by Orientia tsutsugamushi. Despite many attempts to develop a protective strategy, an effective preventive vaccine has not been developed. The identification of appropriate Ags that cover diverse antigenic strains and provide long-lasting immunity is a fundamental challenge in the development of a scrub typhus vaccine. We investigated whether this limitation could be overcome by harnessing the nanoparticle-forming polysorbitol transporter (PST) for an O. tsutsugamushi vaccine strategy. Two target proteins, 56-kDa type-specific Ag (TSA56) and surface cell Ag A (ScaA) were used as vaccine candidates. PST formed stable nano-size complexes with TSA56 (TSA56-PST) and ScaA (ScaA-PST); neither exhibited cytotoxicity. The formation of Ag-specific IgG2a, IgG2b, and IgA in mice was enhanced by intranasal vaccination with TSA56-PST or ScaA-PST. The vaccines containing PST induced Ag-specific proliferation of CD8⁺ and CD4⁺ T cells. Furthermore, the vaccines containing PST improved the mouse survival against O. tsutsugamushi infection. Collectively, the present study indicated that PST could enhance both Ag-specific humoral immunity and T cell response, which are essential to effectively confer protective immunity against O. tsutsugamushi infection. These findings suggest that PST has potential for use in an intranasal vaccination strategy.