• 한국식품과학회지
• /
• 제50권3호
• /
• pp.324-330
• /
• 2018

본 연구에서는 서로 다른 성질을 지닌 기름(MO, CO, PO)을 선정한 후 산화방지제(아스코브산, 토코페롤)의 종류와 농도를 달리한 베타카로텐 함유 나노에멀션을 제조하여, 산화안정성을 검토하였다. 베타카로텐 나노에멀션은 낮은 pH에 비하여 높은 pH에서 화학적으로 더 안정하였다. 또한 베타카로텐의 산화는 기름의 특성에 많은 영향을 받았으며, 지방산 사슬길이가 길며 포화 지방산 함량이 낮은 CO를 유상(oil phase)으로 사용할 경우 베타카로텐 산화를 더욱 가속화시키는 것으로 나타났다. 에멀션 내의 베타카로텐의 분해는 아스코브산과 토코페롤 산화방지제를 첨가함으로써 지연시킬 수 있었다. 그러나 베타카로텐을 함유한 산성 상태의 음료와 식품을 제조하고 이를 장기간 보존하기 위해서는 높은 농도의 산화방지제 첨가가 요구됨을 확인하였다.

• Journal of Electrochemical Science and Technology
• /
• 제10권3호
• /
• pp.335-343
• /
• 2019

In this study, $Sr_2Ni_{1.8}Mo_{0.2}O_{6-{\delta}}$ (SNM) with a double perovskite structure was investigated as an alternative anode for use in the $CH_4$ fuel in solid oxide fuel cells. SNM demonstrates a double perovskite phase over $600^{\circ}C$ and marginal crystallization at higher temperatures. The Ni nanoparticles were exsolved from the SNM anode during the fabrication process. As the SNM anode demonstrates poor electrochemical and electro-catalytic properties in the $H_2$ and $CH_4$ fuels, it was modified by applying a samarium-doped ceria (SDC) coating on its surface to improve the cell performance. As a result of this SDC modification, the cell performance improved from $39.4mW/cm^2$ to $117.7mW/cm^2$ in $H_2$ and from $15.9mW/cm^2$ to $66.6mW/cm^2$ in $CH_4$ at $850^{\circ}C$. The mixed ionic and electronic conductive property of the SDC provided electrochemical oxidation sites that are beyond the triple boundary phase sites in the SNM anode. In addition, the carbon deposition on the SDC thin layer was minimized due to the SDC's excellent oxygen ion conductivity.

• 한국재료학회지
• /
• 제29권4호
• /
• pp.211-220
• /
• 2019

In this study, three kinds of bainitic steel plates are manufactured by varying the chemical compositions and their microstructures are analyzed. Tensile and Charpy impact tests are performed at room and low temperature to investigate the correlation between microstructure and mechanical properties. In addition, heat affected zone (HAZ) specimens are fabricated by a simulation of welding processes, and the HAZ microstructure is analyzed. The base steel that has the lowest carbon equivalent has the highest volume fraction of acicular ferrite and the lowest volume fraction of secondary phases, so the strength is the lowest and the elongation is the highest. The Mo steel has a higher volume fraction of granular bainite and more secondary phases than the base steel, so the strength is high and the elongation is low. The CrNi steel has the highest volume fraction of the secondary phases, so the strength is the highest and elongation is the lowest. The tensile properties of the steels, namely, strength and elongation, have a linear correlation with the volume fraction of secondary phases. The Mo steel has the lowest Charpy impact energy at $-80^{\circ}C$ because of coarse granular bainite. In the Base-HAZ and Mo-HAZ specimens, the hardness increases as the volume fraction of martensite-austenite constituents increases. In the CrNi-HAZ specimen, however, hardness increases as the volume fraction of martensite and bainitic ferrite increases.

• 대한통합의학회지
• /
• 제10권4호
• /
• pp.83-91
• /
• 2022

Purpose: The goal of this study was to investigate changes in dual-task performance according to age and difficulty of cognitive tasks for the in community-dwelling elderly populations, as well as to examine their changes in hand dexterity according to age and cognitive function. Methods: A total of 135 people aged 65 years old and over participated in the study. To evaluate each participant's dual-task performance, each participant completed a dual task. To assess their cognitive function, the Korean Mini-Mental State Examination (MMSE-K) and the Korean version of Montreal Cognitive Assessment (MoCA-K) were the tools used. Participants were divided into three groups based on their age: 65-69 years, 70-79 years, and 80-89 years. Results: The findings showed that age groups and the difficulty of the cognitive task significantly affected the amount of time required for dual-task performance (p<.001). Additionally, the dual-task correct response rate (CRR) decreased significantly with age groups and the difficulty of the cognitive task (p<.001). The amount of time required for finger dexterity performance increased significantly with age groups (mean score±standard deviation [SD]; 19.46±2.26 in subjects aged 65-69 years; 21.92±2.61 in subjects aged 70-79 years; and 23.82±2.92 in subjects aged 80-89 years; p<.001). Moreover, as a result of the correlation between hand dexterity and cognitive function, MoCA-K was -0.563 and MMSE-K was -.412, showing a statistically significant correlation (p<.001). Conclusions: Age and the difficulty of the cognitive task affect the community-dwelling elderly populations in terms of dual-task performance and dual-task CRR. In addition, aging and general cognition have an impact on hand dexterity. Based on the results of this study, it is anticipated that the results will serve as a reference for domestic clinical trials that confirm cognitive decline in the elderly using dual task and hand dexterity evaluation.

• Journal of Veterinary Science
• /
• 제24권3호
• /
• pp.37.1-37.14
• /
• 2023

Background: Toll-like receptor (TLR) agonists have been used as adjuvants to modulate immune responses in both animals and humans. Objectives: The objective of this study was to evaluate the combined effects of the TLR 4 agonist monophosphoryl lipid A (MPL) and the TLR 3 agonist polyinosinic:polycytidylic acid (Poly I:C) on equine peripheral blood mononuclear cells (PBMCs), monocyte-derived dendritic cells (MoDCs), and bone marrow-derived mesenchymal stromal cells (BM-MSCs). Methods: The PBMCs, MoDCs, and BM-MSCs collected from three mixed breed horses were treated with MPL, Poly I:C, and their combination. The mRNA expression of interferon gamma (IFN-γ), interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-12p40, tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) was determined using real-time polymerase chain reaction. Results: The combination of MPL and Poly I:C significantly upregulated immunomodulatory responses in equine cells/ without cytotoxicity. The combination induced greater mRNA expression of pro-inflammatory cytokines IFN-γ and IL-6 than MPL or Poly I:C stimulation alone in PBMCs. In addition, the combination induced significantly higher mRNA expression of IL-1β, IL-6, and IL-12p40 in MoDCs, and IL-8, MCP-1, and VEGF in BM-MSCs compared to stimulation with a single TLR agonist. Conclusions: The combination of MPL and Poly I:C can be used as a potential adjuvant candidate for vaccines to aid in preventing infectious diseases in horses.

• Tribology and Lubricants
• /
• 제12권4호
• /
• pp.18-27
• /
• 1996

An interlaboratory wear testing was performed in order to understand the friction behaviors and the wear mechanisms of the sintered composites. The specimens were the sintered bronze matrix composites having various contents of friction additives, friction control agents and reinforcements. The variation of the wear characteristics according to the constituents of the composites as well as the wear conditions was investigated by SEM, EPMA, OM, the hardness testing and the measurement of friction. The specimen having glass fiber as the matrix reinforcement showed a remarkable increase in wear resistance as increasing the content of glass fiber. Graphite particles in the composites exhibited the lubricating effect and also resulted in the lowering strength of the matrix. Addition of Mo powder to the composites led to the deterioration of wear properties at the room temperature, however, an enhanced wear properties were obtained in the containing Mo at an elevated temperature.

• Journal of Pharmaceutical Investigation
• /
• 제16권4호
• /
• pp.139-147
• /
• 1986

A singly charged methyl orange(MO) anion was found to be extracted with chlorpheniramine maleate(CPM) as a 1 : 1 complex in chloroform. Of various solvents, MO-chloroform system gave a yellow color for CPM, while in the absence of CPM, an organic phase showed almost no color. In this way, the spectrophotometric method was investigated for the determination of CPM by solvent extraction. The addition of alcoholic bolic acid solution to the solvent extract gave a higher color stability and transparency at least 5 days, but the extract alone lost its color intensity significantly. CPM is determined by measuring the absorbance of the extracts over a range of $1{\sim}7{\times}10^{-4}M\;(39{\sim}273\;{\mu}g/ml)$ in aqueous solution at 423 nm. The molar absorptivity was $2.26{\times}10^3\;l,\;mol^{-1},\;cm^{-1}$. The absorbance of the extract was constant in the range of pH $3.7{\sim}4.6$. This novel method was applied for the determination of CPM in artificial and commercial preparations in comparison with the analytical method of CPM tablets in K.P.IV. The results obtained showed that the former was better in accuracy and time consumption than the latter.

• Biomolecules & Therapeutics
• /
• 제25권4호
• /
• pp.354-361
• /
• 2017

Transcriptional co-activator with a PDZ-binding motif (TAZ) is an important factor in lysophosphatidic acid (LPA)-induced promotion of migration and proliferation of human mesenchymal stem cells (MSCs). The expression of TAZ significantly increased at 6 h after LPA treatment, and TAZ knockdown inhibited the LPA-induced migration and proliferation of MSCs. In addition, embryonic fibroblasts from TAZ knockout mice exhibited the reduction in LPA-induced migration and proliferation. The LPA1 receptor inhibitor Ki16425 blocked LPA responses in MSCs. Although TAZ knockdown or knockout did not reduce LPA-induced phosphorylation of ERK and AKT, the MEK inhibitor U0126 or the ROCK inhibitor Y27632 blocked LPA-induced TAZ expression along with the reduction in the proliferation and migration of MSCs. Our data suggest that TAZ is an important mediator of LPA signaling in MSCs in the downstream of MEK and ROCK signaling.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 1993년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
• /
• pp.3-3
• /
• 1993

In mechanical testing of W-Ni-Pe heavy alloys, the cracks nucleate at W/W interface and propagate through W/ Imatrix interface or through matrix phase together with the cleavage of W grains. The mechanical properties can therefore be improved by control of the interfacial strength and area. In this presentation, some experimental result and techniques on this subject will be reviewed and discussed. The hydrogen embrittlement caused by the hydrogen segregation at interfaces during sintering in an hydrogen atmosphere can be removed by an heat-treattnent in vacuum or in an inert atmosphere. The heat-treatment condition can be estimated by using a diffusion equation for a cylindrical shape. The mechanical properties, in particular the impact property, are degraded by the segregation of non-metallic impurities, such as Sand P. The degradation can be prevented by adding a fourth element, such as La or Ca, active with the non-metallic impurities. The cyclic heat-treatment at usual heat-treattnent tempemture causes the penetration of matrix between W/W grain boundaries and results in remarkable increase in impact energy. This is due to an increase in the area of ductile failure during the impact test. The instability of W/matrix interface casued by addition of Mo or Re can be controlled by using W powders of different size. The increase in the interfacial area in found to be related to the presence of non-equilibrium pure W gmins among W(Mo or Re) solid solution gmins.

• 열처리공학회지
• /
• 제15권4호
• /
• pp.178-187
• /
• 2002

Austempered Ductile Iron (ADI) castings having various chemical composition and heat treatment conditions were investigated. Especially, this study was investigated the influence of various parameters on austempering temperature and alloying elements. The addition of Mo, Cu, and Ni individually or combined in these alloys also investigated. The alloying elements influence the austempering reaction, the microstructures, mechanical properties and amount of retained austenite. In this study, the mechanical properties (ultimate tensile strength(UTS), hardness, elongation) are analysed to show the relationship between alloying elements, austempering temperatures and amount of retained austenite. The amount of retained austenite was the range of 15 - 40%. In case of the alloy to witch Mo, Cu, and Ni was added, the amount of retained austenite was the largest at a constant austempering temperature.