• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.85-92
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• 2020

One of the omega-3 essential fatty acids, docosahexaenoic acid (DHA), is a significant constituent of the cell membrane and the precursor of several potent lipid mediators. These mediators are considered to be important in preventing or treating several diseases. Resolvin D5, an oxidized lipid mediator derived from DHA, has been known to exert anti-inflammatory effects. However, the detailed mechanism underlying these effects has not yet been elucidated in human monocytic THP-1 cells. In the present study, we investigated the effects of resolvin D5 on inflammation-related signaling pathways, including the extracellular signal-regulated kinase (ERK)-nuclear factor (NF)-κB signaling pathway. Resolvin D5 downregulated the production of interleukin (IL)-6 and chemokine (C-C motif) ligand 5 (CCL5). Additionally, these inhibitory effects were found to be modulated by mitogen-activated protein kinase (MAPK) and NF-κB in lipopolysaccharide (LPS)-treated THP-1 cells. Resolvin D5 inhibited the LPS-stimulated phosphorylation of ERK and translocation of p65 and p50 into the nucleus, resulting in the inhibition of IL-6 and CCL5 production. These results revealed that resolvin D5 exerts anti-inflammatory effects in LPS-treated THP-1 cells by regulating the phosphorylation of ERK and nuclear translocation of NF-κB.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.40-45
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• 2015

Electrode systems: a protrusion on conductor (POC), a protrusion on enclosure (POE), a crack in epoxy plate and a free particle (FP) were fabricated to simulate insulation defects in a gas insulated switchgear (GIS). $SF_6$ gas was filled in the electrode systems by 3 bar and/or 5 bar, respectively. Partial discharge (PD) pulses were detected through a $50{\Omega}$ non-inductive resistor. A calibration test was carried out according to IEC 60270, and the sensitivity was 0.25 pC/mV. PD pulses were distributed in the phase of $50^{\circ}{\sim}135^{\circ}$ and over 95% of them existed in the phase of $55^{\circ}{\sim}120^{\circ}$ for the POC. PD pulses were distributed in the phase of $230^{\circ}{\sim}310^{\circ}$ and over 90% of them existed in phase of $220^{\circ}{\sim}300^{\circ}$ for the POE. PD pulses occurred in the phase of $40^{\circ}{\sim}60^{\circ}$ and $220^{\circ}{\sim}300^{\circ}$ for the crack, and pulse counts were 25% higher in negative polarity than in positive polarity. PD pulses were distributed in every phase unlike to other three electrode systems and the peak magnitude was measured at $118^{\circ}$ and $260^{\circ}$ for the FP. As described above, PD pulses were observed in positive polarity for the POC, in negative one for the POE, in both one for the crack and the FP. In conclusion, it is expected that the identification rate of defect type can be improved by considering the polarity ratio of PD pulses on the PRPDA method.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.358-359
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• 2012

최근 분극 특성이 상이한 무분극 GaN 에피성장에 관한 심도 있는 연구와 함께 전자-전공 캐리어의 주입 및 캐리어의 거동, 방출되는 편광 특성 및 다양한 물리적 특성들에 대해 보고되고 있으며, 광학적 특성 및 물리적 특성의 확보를 위한 많은 연구가 활발히 진행 중이다 [1]. GaN의 ohmic 접촉(ohmic contact)의 형성은 발광 다이오드(light emitting diode), 레이저 다이오드(Laser), 태양전지(solar cell)와 같은 고신뢰도, 고효율 광전자 소자를 제조하기 위해서는 매우 중요하다 [2]. 그러나 이와 함께 병행 되어야 할 무분극 p-GaN 의 ohmic contact에 관한 연구는 많이 이루어지고 있지 않는 실정이다. 따라서 본 논문에서는 r-plane 사파이어 기판 상에 성장된 p-GaN에서의 ohmic 접촉 형성 연구를 위하여 Ni/Au ohmic 전극의 접촉저항 특성을 연구하였다. 본 실험에서는 성장된 a-plane GaN의 Hole농도가 $3.09{\times}1017cm3$ 인 시편을 사용하였다. E-beam evaporation 장비를 이용하여 Ni/Au를 각각 20 nm 그리고80 nm 증착 하였으며 비접촉저항을 측정하기 위해 Circle-Transfer Length Method (C-TLM) 패턴을 사용하였다. 샘플은 RTA (Rapid Thermal Annealing)를 사용하여 $300^{\circ}C$에서 $700^{\circ}C$까지 온도를 변화시키며 전기적 특성을 비교하여 그림 1(a) 나타내었다. 그림에서 알 수 있듯이 $400^{\circ}C$에서 가장 낮은 비접촉저항 값인 $6.95{\times}10-3{\Omega}cm2$를 얻을 수 있음을 발견하였다. 이 때의 I-V curve 도 그림1(b)에 나타낸 바와 같이 열처리에 의해 크게 향상됨을 알 수 있다. 그러나, $500^{\circ}C$ 이상 온도를 증가시키면 다시 비접촉 저항이 증가하는 것을 관찰하였다. XRD (x-Ray Diffraction) 분석을 통하여 $400^{\circ}C$ 이상열처리 온도가 증가하면 금속 표면에 $NiO_2$가 형성되며, 이에 따라 오믹특성이 저하 된다고 사료된다. 또한 $Ni_3N$의 존재를 확인 하였으며 이는 nonpolar surface의 특성으로 인해 nitrogen out diffusion 현상이 동시에 발생하여 계면에는 dopant로 작용하는 질소 공공을 남기고 표면에 $Ni_3N$을 형성하여 ohmic contact의 특성이 저하되기 때문인 것으로 사료된다.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.213-220
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• 2014

This study was conducted to evaluate the effects of high n-3 or n-6 diet on free fatty acid profile and meat quality traits of pork loin. The 20 heads of commercial $Landrace{\times}Yorkshire{\times}Duroc(LYD)$ crossbreed pigs ($90.9{\pm}2.4BWkg$) were divided into four groups by added fat and oils, such as 5% tallow (Control), 5% linseed oil (T1), 5% safflower oil (T2), and mixture of linseed oil (2.5%) + safflower oil (2.5%) (T3), then reared 4 weeks. Pork loins were taken after slaughter, then sliced in 2 cm thickness and put in low-density polyethylene (LDPE) bag for analysis. T1 showed significantly high concentration of linolenic acid ($2.35{\pm}0.21%$) (p<0.05). The total amount of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA) and poly-unsaturated fatty acid (PUFA) was significantly high in T1 ($36.05{\pm}1.18%$), C ($22.60{\pm}2.11%$) and T2 ($47.80{\pm}1.29%$), respectively (p<0.05). However, the ratio of n-6:n-3 was significantly low in T1 ($11.57{\pm}0.90$) than that of T2 ($37.56{\pm}12.51$) (p<0.05). There was no signigicant difference in lightness, redness, pH, water holding capacity and cooking loss between treatments (p>0.05). However, the yellowness of T2 was significantly higher than others (p<0.05). From those results, it was considered that feeding high n-3 and n-6 fatty acid diet to pig enables modify fatty acid profile of pork without any side effect on meat quality.

• Restorative Dentistry and Endodontics
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• v.28 no.4
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• pp.341-347
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• 2003

This study was conducted to evaluate the temperature rise on the root surface while the root canal is being obturated using continuous wave of condensation technique. Maxillary central incisor was prepared for repeated canal obturation. Ten thermocouples (Omega Engineering Inc., Stanford, USA) were placed at 1 mm increment from the anatomical root apex. The real temperature of Buchanan plugger was recorded before insertion into the root canal. The root canal was obturated with continuous wave of condensation technique as described by Buchanan and the root surface temperature was recorded during obturation at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings of System B HeatSource (Model 1005, Analytic technologies, Redmond, WA, USA). After completion of the temperature recording, the dentinal-cementum thickness at each sites was measured. The data were analyzed using one-way ANOVA followed by Scheffe's test and linear regression test. The results were as follows. 1. When the temperature was set at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed $130.82{\pm}2.96^{\circ}C,{\;}158.00{\pm}5.26^{\circ}C,{\;}215.92{\pm}6.91^{\circ}C{\;}and{\;}249.88{\pm}3.65^{\circ}C$ respectively. 2. The position of 8 mm from the anatomical apex showed the highest temperature increase at each temperature settings and it was significantly higher than those of other positions (p<0.0l). The temperature rise was constantly increased toward coronal portion from apex of the root. 3. The maximum temperature increase on the root surface was $2.37{\pm}0.09^{\circ}C{\;}at{\;}150^{\circ}C{\;}setting,{\;}3.11{\pm}0.12^{\circ}C{\;}at{\;}200^{\circ}{\;}setting,{\;}3.93{\pm}0.09^{\circ}C{\;}at{\;}250^{\circ}C{\;}setting{\;}and{\;}5.69{\pm}0.15^{\circ}C{\;}at{\;}300^{\circ}C$ setting respectively. These results suggest that it be relatively kind to the supporting tissues of the root that the root canal is obturated using continuous wave of condensation technique at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings on digital temperature display of System B HeatSource.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.42-47
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• 1986

The fatty acid composition of lipids extracted from 18 kinds of salted and fermented sea foods which have been consumed in Korea were examined. The lipid contents of salted and fermented sea foods showed wide difference (0.8-11.9%) depending on species and portions of raw materials. In fatty acid composition of salted and fermented sea foods prepared with whole fishes, the saturated fatty acid was the most predominant component, and the major fatty acids were 16:0, 18:1, 22:6, 16:1 and 20:5. In case of salted and fermented products prepared with gills, roe or intestines, the polyenoic fatty acid was the main component, the major fatty acids were 18:1, 16:0, 22:6, 20:5, 16:1 and 18:3. In these products the composition ratios of 20:5 and 18:3 were higher, and that of 16:0 and 16:1 were slightly lower as compared with salted and fermented whole fish products. And in case of salted and fermented crustacea and mollusk, the polyenoic fatty acids such a 22:6 and 20:5 were the most predominant component, the abundant fatty acids were 22:6, 16:0, 20:5, 18:1 and 16:1. Judging from results, salted and fermented sea foods were abundant of the highly unsaturated fatty acids such as 20:5, 22:6 inspite of the long fermentation periods.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.278-289
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• 2021

The rapid aging of society has led to a surge in cognitive dysfunction in the elderly. As there is limited evidence for the development of dementia in medicine, a shift in focus on prevention strategies using bioactive compounds in food is required. This systematic review evaluated the effects of various bioactive compounds on age-associated cognitive decline. The literature was searched for terms related to bioactive compounds in cognitive decline and article selection was limited to clinical randomized controlled trials for a single bioactive compound. We identified 21 studies that evaluated the strength of the evidence. ω-3 fatty acids and vitamin B presented a strong evidence level, whereas vitamin D and E, anserine/carnosine, and chromium were defined as having moderate levels of evidence. ω-3 fatty acids relieved cognitive decline and reduced amyloid β-related protein accumulation. Vitamin B decreased homocysteine levels, which is accompanied by alleviation of cognitive function. In conclusion, ω-3 and vitamin B have the potential to improve age-associated cognitive decline.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.375-385
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• 2010

An investigation was conducted to evaluate the effects of supplementing Alisma canaliculatum, Viscum album and Cornus officinalis probiotics on the growth performance and immune response in growing pigs. This experiment was conducted using 120 pigs (crossing of Landrace${\times}$Yorkshire and castrated) which were assigned to 5 treatments in 3 replications with 8 pigs per replications. The dietary treatments were NC group (without antibiotics), PC group (basal+Oxytetracycline 50ppm), AC group (basal+A. canaliculatum 0.5%), VA group (basal+V. album 0.5%) and COP group (basal+C. officinalis probiotics 0.5%). The initial body weights of pigs were 35kg on average and the experiment lasted for 9 weeks. The experimental animals were kept in the pens following a completely randomized design. They were provided the diets adequate for grower stage as recommended by NRC (ME:3,265 kcal/kg and CP:16%). COP fed pigs showed lower weight gain up to 6 weeks of age compared to NC group and other groups without significant differences (P>0.05). The carcass weights of pigs fed VA and COP were significantly higher compared to NC group (P<0.05), Back fat thicknesses groups fed three different additives were higher than NC group and lower then PC group (P<0.05). Crude fat contents in loin meat were significantly lower in groups fed three different additives while moisture contents of those three groups were higher than other groups (P<0.05). The thiobarbituric acid reaction substance (TBARS) value measured at fresh and $2^{nd}$ weeks was lower in additives fed groups but no statistical differences were observed among the treatments (P>0.05). Significantly highest PUFA (16.42g/100g) and ${\omega}$-3 fatty acids (ALA, EPA and DHA) content of meat were observed in COP fed pigs compared to NC group (P>0.05), which might mean that three additives function to enhance serum IgG in pigs. In consequence, it can be suggested that AC, VA and COP may have a potential to replace antibiotics as growth promoter and immune enhancer in the diets for growing pigs.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.985-994
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• 2000

Objective : There are some advantages of trigeminal evoked potential(TEP) recording compared to other somatosensory evoked potential(SSEP) recordings. The trigeminal sensory pathway has a pure sensory nerve branch, a broader receptive field in cerebral cortex, and a shorter pathway. Despite these advantages, there is little agreement as to what constitutes a normal response and what wave forms truly characterize the intraoperative TEP. This study presents the normative data of TEP recorded on the epidural surface of the rat with a platinum ball electrode. Materials & Methods : Under general anesthesia with urethane, the adult Sprague-Dawley male rats(300-350g) were given electrical stimulation with two stainless steel electrodes which were inserted into the subcutaneous layer of the area around whiskers. A reference electrode was positioned in the temporalis muscle ipsilateral to the recording site. Results : TEPs were recorded in the Par I area of somatosensory cortex and recorded most apparently on the point of 2mm posterior from the bregma and 6mm lateral from the midline. The typical wave form consisted of 5 peaks (N1-P1-N2-P2-N3 according to emerging order, upward negativity). Each latency to corresponding peaks was not influenced by the different intensities of stimulation, especially from 1 to 5mA. Average latencies of 5 peaks were in the following order ; 7.7, 11.1, 15, 22.3, 29.4ms. There was also no significant difference between latencies before and after administration of muscle relaxant(pancuronium). For the electrophysiological localization of recorded waves, the action potential of a single unit was recorded with glass microelectrode(filled with 2M NaCl, $3-5M{\Omega}$) in the thalamus of rat. A sharp wave was recorded in the VPM nucleus, in which the latency was shorter than that of N1. This suggests that all 5 peaks were generated by neural activities in the suprathalamic pathway. Conclusion : In terms of recording near-field potentials, our data also suggests that TEP in the rat may be superior to other SSEPs. In overall, these results may afford normative data for the studies of supratentorial lesions such as hydrocephalus or cerebral ischemia which can have an influence on near-field potentials.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1254_1255
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• 2009

The composites were fabricated by adding 30, 35, 40, 45[vol.%] Zirconium Diboride(hereafter, $ZrB_2$) powders as a second phase to Silicon Carbide(hereafter, SiC) matrix. The physical, mechanical and electrical properties of electroconductive SiC ceramic composites by Spark Plasma Sintering(hereafter, SPS) were examined. Reactions between $\beta$-SiC and $ZrB_2$ were not observed in the XRD analysis. The relative density of SiC+30[vol.%]$ZrB_2$, SiC+35[vol.%]$ZrB_2$, SiC+40[vol.%]$ZrB_2$ and SiC+45[vol.%]$ZrB_2$ composites are 88.64[%], 76.80[%], 79.09[%] and 88.12[%], respectively. The XRD phase analysis of the electroconductive SiC ceramic composites reveals high of SiC and $ZrB_2$ and low of $ZrO_2$ phase. The electrical resistivity of SiC+30[vol.%]$ZrB_2$, SiC+35[vol.%]$ZrB_2$, SiC+40[vol.%]$ZrB_2$ and SiC+45[vol.%]$ZrB_2$ composites are $6.74{\times}10^{-4}$, $4.56{\times}10^{-3}$, $1.92{\times}10^{-3}$ and $4.95{\times}10^{-3}[{\Omega}{\cdot}cm]$ at room temperature, respectively. The electrical resistivity of SiC+30[vol.%]$ZrB_2$, SiC+35[vol.%]$ZrB_2$, SiC+40[vol.%]$ZrB_2$ and SiC+45[vol.%]$ZrB_2$ are Positive Temperature Coefficient Resistance(hereafter, PTCR) in temperature ranges from 25[$^{\circ}C$] to 500[$^{\circ}C$]. It is convinced that SiC+40[vol.%]$ZrB_2$ composite by SPS can be applied for heater or electrode.