• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.250-251
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• 2009

• East Asian mathematical journal
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• v.26 no.3
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• pp.423-427
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• 2010

In this paper, we give an upper bound for dominations of Steinhaus graphs, and the domination numbers of the bipartite Steinhaus graphs. Also, we give an upper bound for Nordhaus-Gaddum type result for the bipartite Steinhaus graphs.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.399-405
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• 1997

Progesterone is necessary for successful pregnancy and had immunosuppressive properties. Peripheral blood mononuclear cells (PBMC) from many women with unexplained recurrent spontaneous abortion responded to trophoblast extract in vitro by prolifertion and releasing soluble, heat-labile factors that are toxic to mouse embryos (embryotoxic factors). Accumulating evidence suggests that T Helper (Th)-1 type immunity to trophoblast is correlated with embryotoxic factor production and is associated with pregnancy loss, while Th2-type immunity is associated with successful gestation. The objective of this study was to determine whether progesterone can inhibit Th1-type cytokine secretion (IFN-${\gamma}$, TNF-${\alpha}$) by trophoblast-activated peripheral blood mononuclear cells from 23 nonpregnant women (age 25-35) with unexplained recurrent abortion (median 5, range 3 to 15)who otherwise produce embryotoxic factors in response to trophoblast. We also determined whether progesterone affected Th2-type cytokines (IL-4, IL-10) in this system in vitro and if IL-10 (1,500 pg/mL) could inhibit Th1-type immunity to trophoblast. IFN-${\gamma}$ was detected in 17 of 23 (74%) trophoblast stimulated PBMC culture supernatants ($77.94{\pm}23.79$ pg/mL) containing embryotoxic activity. TNF-${\alpha}$ was detected in 19 (83%) of these same supernatants ($703.15{\pm}131.36$ pg/mL). In contrast, none of the supernatants contained detectable levels of IL-4 or IL-10. Progesterone ($10^{-5}$, $10^{-7}$, $10^{-9}$M) inhibited Th1-type immunity in a dose dependent manner, but had no effect on Th2-type cytokine secretion. The inhibitory effects of progesterone were abrogated with RU486, but did not affect Th2-type cytokine secretion in trophoblast-activated cell cultures. IL-10, like progesterone also inhibited Th1-type cytokine secretion but had no effect on Th2-type cytokines. These data suggest that therapies designed to suppress Th1-type cytokine secretion in women with recurrent abortion who have evidence of Th1-type immunity to trophoblast may be efficacious in preventing pregnancy loss and should be tested in appropriately designed clinical trials.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.234-240
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• 1994

The essential oils of Thymus quinquecostatus Celakov. and T. magnus Nakai, respectively, were isolated by using a modified Likens-Nickerson type steam distillation and extraction apparatus and analyzed by gas chromatography and gas chromatography-mass spectrometry. The oil content of T. quinquecostatus was 1.94%, and that of T. magnus was 1.91% in mixed leaves and stems and 0.68% in flowers. Among 38 components identified in either mixed leaves and stems or flowers the major components in essential oil isolated from T. quinquecostatus were thymol(39.8%), ${\gamma}-terpinene(10.0%)$ ${\rho}cymene(9.2%)$ and camphor(5.9%) while those from mixed leaves and stems of T. magnus were thymoI(54.7%), ${\gamma}-terpinene(15.8%)$, ${\rho}cymene(6.7%)$ and carvacroI(3.2%). The contents of ${\alpha}-pinene$, camphene, camphor, bornyl acetate and ${\alpha}-terpinene+borneol$ were higher in T. quinquecostatus than in T. maglnus but ${\gamma}-terpinene$ and thymol were higher in T. magnus than in T. quinquecostatus. Comparing leaves and stems with flowers in T. magnus, peak area percentage(%) of ${\gamma}-terpinene$, ${\alpha}-terpinene$ were higher in mixed leaves and stems than in flowers, whereas ${\rho}cymene$ was predominantly higher in flowers than in leaves and stems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1156-1164
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• 2010

Structured lipids (SLs) were synthesized by enzymatic interesterification with evening primrose oil (EPO) and rice bran oil (RBO) in a batch-type reactor. The interesterification was performed using a water shaker for 24 hr at $55^{\circ}C$. Mixing speed was set at 200 rpm and Lipozyme RM IM (immobilized lipase from Rhizomucor miehei, 10% by weight of total substrates) was used as a biocatalyst. Rice bran oil and evening primrose oil were interesterified with various molar ratios (RBO : EPO, 1:3, 1:4, and 1:5 mol/mol). Reversed-phase high performance liquid chromatography connected with evaporative light-scattering detector was performed to separate the triacylglycerol (TAG) species of SLs. In the fatty acid analysis, $\gamma$-linolenic acid (7.9 mol%), linoleic acid (67.3 mol%) and oleic acid (13.2 mol%) were the most abundant fatty acids in the SLs. During 24 hr reaction, most of the reaction occurred within 3 hr. TAG compositions, tocopherols and phytosterols were also analyzed. In the TAG species analysis, LLL (ECN=42, L=linoleic acid) dramatically decreased when the reaction time increased.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.201-206
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• 2023

In order to improve the spatial resolution of the gamma camera, the size of the hole in the collimator must be reduced, so the sensitivity is reduced. In order to improve the sensitivity, the size of the hole must be increased, and thus the spatial resolution is reduced. In other words, spatial resolution and sensitivity show opposite characteristics. In this study, a gamma camera was designed to improve both spatial resolution and sensitivity. In order to obtain higher sensitivity in gamma cameras with the same spatial resolution, the structure of the scintillator was designed differently from the existing system. A scintillation pixel was used, and a partition wall was placed between the scintillation pixels to prevent incident gamma rays from being transmitted to other scintillation pixels to interact. Geant4 Application for Tomographic Emission (GATE) simulation was performed to evaluate the performance of the designed gamma camera. When the same sensitivity as the block-type scintillator was obtained, the spatial resolution increased by 16.5%, and when the same spatial resolution was obtained, the sensitivity increased by 61.5%. It is considered that the use of the gamma camera designed in this study can improve the sensitivity compared to the existing system while securing excellent spatial resolution.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.201-207
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• 2011

Peroxisome proliferator-activated receptors (PPARs) are members of nuclear receptors and their activation induces regulation of fatty acid storage and glucose metabolism. Therefore, the $PPAR\gamma$ is a major target for the treatment of type 2 diabetes mellitus. In order to generate pharmacophore model, 1080 known agonists database was constructed and a training set was selected. The Hypo7, selected from 10 hypotheses, contains four features: three hydrogen-bond acceptors (HBA) and one general hydrophobic (HY). This pharmacophore model was validated by using 862 test set compounds with a correlation coefficient of 0.903 between actual and estimated activity. Secondly, CatScramble method was used to verify the model. Hence, the validated Hypo7 was utilized for searching new lead compounds over 238,819 and 54,620 chemical structures in NCI and Maybridge database, respectively. Then the leads were selected by screening based on the pharmacophore model, predictive activity, and Lipinski's rules. Candidates were obtained and subsequently the binding affinities to $PPAR\gamma$ were investigated by the molecular docking simulations. Finally the best two compounds were presented and would be useful to treat type 2 diabetes.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.346-353
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• 2009

Viral, bacterial, and fungal infection can be transmitted from donor to recipient via transplantation of human amniotic membrane. Therefore human amniotic membrane for transplantation should be disinfected and sterilized before use. The purpose of this study was to examine the efficacy of the disinfection process and sterilization processes used at human tissue bank in the inactivation of viruses, bacteria, and fungi. A variety of experimental model viruses, bacteria, and fungus for human pathogens, including the human immunodeficiency virus type 1 (HIV-1), bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), hepatitis A virus (HAV), porcine parvovirus (PPV), Escherichia coli, Bacillus subtilis, and Candida albicans were all selected for this study. Enveloped viruses such as HIV-1, BHV, and BVDV were effectively inactivated to undetectable levels by 70% ethanol treatment, gamma irradiation process, and ethylene oxide (EO) gas sterilization process. Also non-enveloped viruses such as HAV and PPV were effectively inactivated to undetectable levels by gamma irradiation and EO gas treatment. However HAV and PPV showed high resistance to 70% ethanol treatment. E. coli and C. albicans were effectively inactivated to undetectable levels by 70% ethanol treatment, gamma irradiation process, and EO gas treatment. Also B. subtilis was effectively inactivated to undetectable levels by gamma irradiation process and EO gas treatment. However it showed high resistance to 70% ethanol treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.927-932
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• 2007

This paper proposes a robust back-stepping control with polynomial-type PD input for flexible joint robot manipulators to overcome parameter uncertainty. In the first step, a fictitious control is designed with polynomial-type PD input for the rigid link dynamic by the H-infinity control method. In second and third steps, the other fictitious control and real control are designed using saturation control and polynomial-type PD input based on the Lyapunov's second method. In each step, the designed robust inputs satisfy the L2-gain, which is equal to or less than gamma in the closed loop system. In contrast with the previous researches, the proposed method proves performance relations with PD gain from the robust gain. The performance robustness of the proposed control is verified through a 2-DOF robot manipulator with joint flexibility.