• 한국분말재료학회지
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• 제11권1호
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• pp.50-54
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• 2004

Nanoparticles of iron oxides have been prepared by the levitational gas condensation (LGC) method, and their structural and magnetic properties were studied by XRD, TEM and Mossbauer spectroscopy. Fe clusters were evaporated from a surface of the levitated liquid Fe droplet and then condensed into nanoparticles of iron oxide with particle size of 14 to 30 nm in a chamber filled with mixtures of Ar and $O_2$ gases. It was found that the phase transition from both $\gamma$-$Fe_2O_3$ and $\alpha$-Fe to $Fe_3O_4$, which was evaluated from the results of Mossbauer spectra, strongly depended on the $O_2$ flow rate. As a result, $\gamma$-$Fe_2O_3$ was synthesized under the $O_2$ flow rate of 0.1$\leq$$Vo_2$(Vmin)$\leq$0.15, whereas $Fe_3O_4$ was synthesized under the $O_2$, flow rate of 0.15$\leq$$Vo_2$(Vmin)$\leq$0.2.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.450-459
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• 2017

This study evaluated the effects of culture conditions, including carbon and nitrogen sources, L-monosodium glutamate (MSG), and initial pH, on gamma-aminobutyric acid (GABA) production by Lactobacillus brevis HYE1 isolated from kimchi, a Korean traditional fermented food. L. brevis HYE1 was screened by the production analysis of GABA and genetic analysis of the glutamate decarboxylase gene, resulting in 14.64 mM GABA after 48 h of cultivation in MRS medium containing 1% (w/v) MSG. In order to increase GABA production by L. brevis HYE1, the effects of carbon and nitrogen sources on GABA production were preliminarily investigated via one-factor-at-a-time optimization strategy. As the results, 2% maltose and 3% tryptone were determined to produce 17.93 mM GABA in modified MRS medium with 1% (w/v) MSG. In addition, the optimal MSG concentration and initial pH were determined to be 1% and 5.0, respectively, resulting in production of 18.97 mM GABA. Thereafter, response surface methodology (RSM) was applied to determine the optimal conditions of the above four factors. The results indicate that pH was the most significant factor for GABA production. The optimal culture conditions for maximum GABA production were also determined to be 2.14% (w/v) maltose, 4.01% (w/v) tryptone, 2.38% (w/v) MSG, and an initial pH of 4.74. In these conditions, GABA production by L. brevis HYE1 was predicted to be 21.44 mM using the RSM model. The experiment was performed under these optimized conditions, resulting in GABA production of 18.76 mM. These results show that the predicted and experimental values of GABA production are in good agreement.

• Corrosion Science and Technology
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• 제14권3호
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• pp.132-139
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• 2015

Turbocharger steels were manufactured by the powder metallurgical and casting method. They consisted primarily of a large amount of ${\gamma}$-Fe, a small amount of ${\alpha}$-Fe, and fine $Nb_6C_5$ precipitates. The casting method was better than the powder metallurgical method, because a sound matrix with little oxides were obtained. When turbocharger steels were oxidized at $900^{\circ}C$ for 50 h, $Mn_2VO_4$ and (Mn,Si)-oxides were formed along grain boundaries, while $Mn_2O_3$ and $CrMn_2O_4$ were formed intragranularly. Fe, Nb, and Ni were depleted in the oxide scale.

• Plant Biotechnology Reports
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• 제4권3호
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• pp.237-242
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• 2010

Six parent and their 12 gamma ray-induced somatic flower colour mutants of garden rose were characterized to discriminate the mutants from their respective parents and understanding the genetic diversity using Random amplification of polymorphic DNA (RAPD) markers. Out of 20 primers screened, 14 primers yielded completely identical fragments patterns. The other 7 primers gave highly polymorphic banding patterns among the radiomutants. All the cultivars were identified by using only 7 primers. Moreover, individual mutants were also distinguished by unique RAPD marker bands. Based on the presence or absence of the 48 polymorphic bands, the genetic variations within and among the 18 cultivars were measured. Genetic distance between all 18 cultivars varied from 0.40 to 0.91, as revealed by Jaccard's coefficient matrix. A dendrogram was constructed based on the similarity matrix using the Neighbor Joining Tree method showed three main clusters. The present RAPD analysis can be used not only for estimating genetic diversity present in gamma ray-induced mutants but also for correct identification of mutant/new varieties for their legal protection under plant variety rights.

• Journal of Astronomy and Space Sciences
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• 제30권2호
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• pp.83-85
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• 2013

Anomalous X-ray pulsars (AXPs) are thought to be magnetars which are young isolated neutron stars with extremely strong magnetic fields of > $10^{14}$ Gauss. Their tremendous magnetic fields inferred from the spin parameters provide a huge energy reservoir to power the observed X-ray emission. High-energy emission above 0.3 MeV has never been detected despite intensive search. Here, we present the possible Fermi Large Area Telescope (LAT) detection of ${\gamma}$-ray pulsations above 200 MeV from the AXP, 1E 2259+586, which puts the current theoretical models of ${\gamma}$-ray emission mechanisms of magnetars into challenge. We speculate that the high-energy ${\gamma}$-rays originate from the outer magnetosphere of the magnetar.

• 한국지능시스템학회논문지
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• 제14권3호
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• pp.316-323
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• 2004

이 논문에서는 특이섭동 T-S 퍼지시스템의 $H_{\infty}$ 출력 궤환 제어기의 설계를 취급한다. 특이섭동 시스템에서 저속 부시스템과 고속 부시스템의 $H_{\infty}$ 노옴이 각각 ${\gamma}$ 보다 적다면 충분히 적은 ${\varepsilon}$>0에 대해서 특이섭동 퍼지시스템의 $H_{\infty}$ 노옴이 ${\gamma}$보다 적음을 증명한다. 이러한 사실을 이용하여 특이섭동 파라메터 ${\varepsilon}$과 무관한 선형 행렬부등식을 기반으로하는 제어기 설계법을 제시한다. 제시된 설계법의 효용성을 입증하기 위하여 수치예를 보여준다.

• Food Science and Biotechnology
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• 제14권3호
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• pp.355-357
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• 2005

This study evaluated the binding abilities of rabbit anti-ovalbumin (OVA) immunoglobulin G (IgG) and egg-allergic patient IgE on gamma-irradiated OVA during proteolysis using pepsin and trypsin. The concentrations of both the intact and the irradiated OVAs decreased during proteolysis when detected with IgG However, when detected by patient IgE the concentration of the intact OVA decreased up to 30 min after the trypsin treatment and increased thereafter. Irradiated OVA detected by patient IgE showed a lower initial concentration (0.16%) than that of the intact OVA, and this reduced concentration was maintained stably. The results indicate that irradiation, rather than enzymatic treatment, could reduce the binding of the irradiated and enzyme-treated OVA. Therefore, gamma irradiation has potential as an effective method to reduce OVA-induced allergy and may enhance the safety of egg-allergic individuals.

• 대한한방소아과학회지
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• 제21권2호
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• pp.13-34
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• 2007

Objectives The purpose of this study is to examine of the effect of SPAR medicines on the atopy eruption control Methods This experiment is about the expression of IgE, IL-4, IL-6, IL_13, IgM, IgG2a, IgG2b, IgG1 level in serum, and $IFN-{\gamma}$ production by SPAR medicines. We assayed for $CD3e^+/CD69^+$, $CD044^+/CD19^+$ positive cells by flow cytometry in splenocytes and observed the revelation of $CD3e^+/CD69^+$, $CD4^+/CD8^+$, $CD44^+/CD19^+$ marker in PBMC, spleen and DLN. We also observed the outturn of IL-4, IL-5, CCR3, $IFN-{\gamma}$ in skin of a NC/Nga mice. We also analyzed NC/Nga mice's ear and neck-back skin after biopsy and dye by H&E staining method, measured about epidermis and dermis part in comparison with control group. Results SPAR medicines as treatment result to a NC/Nga mice, clinical skin severity score decreased remarkably than the ontrol group. Specially, experiment was results by measuring IgE and IL-6 content in serum 8 weeks, 10 weeks, 12 weeks, 16 weeks, 20 weeks respectively, and it was decreased remarkably than the control group. After experiment ended, the result that observed the revelation CD3e, CD4, CD8, CD19, CD69, CD11a marker in lymph node establishment were observed and that B/T rate becomes recover as normal with political background. In addition to that, the control group was decreased in the measured value of IL-4, IL-5, IL-13, IgM, IgG2a, IgG1's level in serum, and $IFN-{\gamma}$' production secreted in Th1 cell displayed increase by SPAR medicines. IL-4, IL-5, CCR3, and $IFN-{\gamma}$'s gene revelation amount displayed marked decrease than the control group in result that observe effect that get in skin of a NC/Nga dermatitis mouse. Moreover in culture supernatant which cultivate for 14 days after separate skin cell, IL-13 and IL-6 production, and $CD69^+/CD3e^+$, $CD44^+/CD19^+$ expression cell number was decreased than the control group's number. Course inflammation immunocyte permeated of result that effect that SPAR medicines get to NC/Nga mice's skin establishment analyzes ear and neck-back skin after biopsy, and dye by H&E method decreased about epidermis and inflammation of dermis part remarkably than the control group. Conclusions Th1 cell and Th2 cell observe to be shifted by secretion amount of IL-4 and $IFN-{\gamma}$ by SPAR medicines could know that SPAR medicines can be use for treatung allergy autoimmune disease.

• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.293-300
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• 2017

Prostaglandin $D_2$ ($PGD_2$) may act against myocardial ischemia-reperfusion (I/R) injury and play an anti-inflammatory role in the heart. Although the effect of $PGD_2$ in regulation of ANP secretion of the atrium was reported, the mechanisms involved are not clearly identified. The aim of the present study was to investigate whether $PGD_2$ can regulate ANP secretion in the isolated perfused beating rat atrium, and its underlying mechanisms. $PGD_2$ (0.1 to $10{\mu}M$) significantly increased atrial ANP secretion concomitantly with positive inotropy in a dose-dependent manner. Effects of $PGD_2$ on atrial ANP secretion and mechanical dynamics were abolished by AH-6809 ($1.0{\mu}M$) and AL-8810 ($1.0{\mu}M$), $PGD_2$ and prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$) receptor antagonists, respectively. Moreover, $PGD_2$ clearly upregulated atrial peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and the $PGD_2$ metabolite 15-deoxy-${\Delta}12$, 14-$PGJ_2$ (15d-$PGJ_2$, $0.1{\mu}M$) dramatically increased atrial ANP secretion. Increased ANP secretions induced by $PGD_2$ and 15d-$PGJ_2$ were completely blocked by the $PPAR{\gamma}$ antagonist GW9662 ($0.1{\mu}M$). PD98059 ($10.0{\mu}M$) and LY294002 ($1.0{\mu}M$), antagonists of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling, respectively, significantly attenuated the increase of atrial ANP secretion by $PGD_2$. These results indicated that $PGD_2$ stimulated atrial ANP secretion and promoted positive inotropy by activating $PPAR{\gamma}$ in beating rat atria. MAPK/ERK and PI3K/Akt signaling pathways were each partially involved in regulating $PGD_2$-induced atrial ANP secretion.

• 한국식품과학회지
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• 제29권4호
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• pp.641-647
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• 1997

신선초의 전초, 줄기, 잎에서 제조된 생즙의 휘발성 향기성분을 n-pentane과 diethylether혼합용액(1:1, v/v)을 추출용매로 하여 연속수증기증류추출(SDE)방법으로 추출하였다. 이들 성분을 GC의 Rl 및 GC/MS에 의해 확인 동정하였다. 신선초의 전초, 줄기, 잎의 생즙에서 각각 52종, 38종, 43종의 화합물이 분리 동정 되었다. 전초에서 분리 동정된 성분들은 탄화수소류가 25종으로 다수를 차지하였으며, 알코올류가 15종, 알데히드류가 3종, 에스테르류가 6종, 케톤류가 2종 그리고 산류가 1종 동정되었다. 신선초의 줄기에서도 전초에서 분리 동정되었던 성분들과 같은 화합물이 확인되었는데 탄화수소류가 20종, 알코올류가 14종, 에스테르류가 4종, 산류가 1종 확인되어 총 38종이 동정된 반면에 전초와 잎과는 달리 알데히드류와 케톤류는 동정되지 않았다. 신선초의 잎에서는 탄화수소류가 19종, 알코올류가 11종, 알데히드류가 4종, 에스테르류가 6종, 케톤류가 2종 그리고 산류가 1종이 확인되어 총 44종이 동정되었다. 신선초의 전초, 줄기 그리고 잎에서 ${\gamma}-Terpinene$과 germacrene B이 가장 많은 함량을 차지하였으며, ${\delta}-3-carene$, cis-3-hexen-1-ol 그리고 ${\gamma}-elemene$도 다량 확인되어 이러한 화합물이 신선초에서 추출한 정유의 주요성분으로 확인되었다. 신선초의 각 부위에서 분리 동정된 정유성분을 정량한 결과, 잎에 171.42 mg/kg로 많이 함유되어 있었으며, 전초에 124.85 mg/kg, 줄기에 55.25 mg/kg가 함유되어 있었다. 신선초의 전초에서 분리 동정된 52종의 화합물에는 monoterpene hydrocarbon, sesquiterpene hydrocarbon과 이들의 유도체들인 terpenoid계 화합물이 40종 확인되었는데, 신선초 정유성분 중 terpenoid계 화합물이 전초, 줄기 그리고 잎에 각각 75.76%, 86.42%, 78.21%의 비율로 포함되어 이들이 신선초 생즙에서 추출한 정유성분의 주체로 간주되었다.