• BMB Reports
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• v.49 no.10
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• pp.554-559
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• 2016

Mycobacterium abscessus, a member of the group of non-tuberculous mycobacteria, has been identified as an emerging pulmonary pathogen in humans. However, little is known about the protective immune response of antigen-presenting cells, such as dendritic cells (DCs), which guard against M. abscessus infection. The M. abscessus gene MAB1843 encodes ᴅ-alanyl-ᴅ-alanine dipeptidase, which catalyzes the hydrolysis of ᴅ-alanyl-ᴅ-alanine dipeptide. We investigated whether MAB1843 is able to interact with DCs to enhance the effectiveness of the host's immune response. MAB1843 was found to induce DC maturation via toll-like receptor 4 and its downstream signaling pathways, such as the mitogen-activated protein kinase and nuclear factor kappa B pathways. In addition, MAB1843-treated DCs stimulated the proliferation of T cells and promoted Th1 polarization. Our results indicate that MAB1843 could potentially regulate the immune response to M. abscessus, making it important in the development of an effective vaccine against this mycobacterium.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.21-27
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• 2011

The comparison work was conducted for the methanol steam reforming among commercial Cu-based catalysts, viz. ICI-M45, which is for the methanol synthesis, MDC-3 and MDC-7, which are for the water-gas shift reaction. The catalytic activity for the water-gas shift reaction was also compared over three catalysts. Among them, MDC-7 showed the highest methanol conversion and formation rate of hydrogen and carbon dioxide at 473 K for the methanol steam reforming. To find out any promotional effect between ICI-M45 and MDC-7, three different packing methods with these two catalysts were examined. However, no synergistic effect was observed. The catalytic activity for watergas shift reaction decreased in the following order: MDC-7 > MDC-3 > ICI-M45. The highest activity of MDC-7 for the methanol steam reforming as well as the water-gas shift reaction can be due to its high surface area, copper dispersion, and an adequate Cu/Zn ratio.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.293-298
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• 2015

This study aimed at characterizing the rheological properties and molecular weight of tara gum fractionated with ammonium sulfate. Tara gum was separated into six fractions (F1-F6) at different concentrations of ammonium sulfate, ranging from 12.21 to 28.67% (w/w). The yield of the tara gum fractions ranged between 4.98 and 17.47%, and their intrinsic viscosity ranged from 9.38 to 12.44 dL/g. The highest values of Huggins coefficient (k') and viscosity-molecular mass were observed in fraction F3. The shear viscosity of the tara gum fractions was measured by a cone-plate viscometer, clearly showing shear thinning behavior. Size-exclusion chromatography results showed that the molecular weight ranged between 635.42 and 776.71 kg/mol, and the F3 fraction exhibited higher values of molecular weight.

• Journal of electromagnetic engineering and science
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• v.1 no.1
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• pp.73-77
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• 2001

We studied the fabrication of GaAs-based pseudomorphic high electron mobility transistors(PHEMT`s) for the purpose of millimeter- wave applications. To fabricate the high performance GaAs-based PHEMT`s, we performed the simulation to analyze the designed epitaxial-structures. Each unit processes, such as 0.1 m$\mu$$\Gamma$-gate lithography, silicon nitride passivation and air-bridge process were developed to achieve high performance device characteristics. The DC characteristics of the PHEMT`s were measured at a 70 $\mu$m unit gate width of 2 gate fingers, and showed a good pinch-off property ($V_p$= -1.75 V) and a drain-source saturation current density ($I_{dss}$) of 450 mA/mm. Maximum extrinsic transconductance $(g_m)$ was 363.6 mS/mm at $V_{gs}$ = -0.7 V, $V_{ds}$ = 1.5 V, and $I_{ds}$ =0.5 $I_{dss}$. The RF measurements were performed in the frequency range of 1.0~50 GHz. For this measurement, the drain and gate voltage were 1.5 V and -0.7 V, respectively. At 50 GHz, 9.2 dB of maximum stable gain (MSG) and 3.2 dB of $S_{21}$ gain were obtained, respectively. A current gain cut-off frequency $(f_T)$ of 106 GHz and a maximum frequency of oscillation $(f_{max})$ of 160 GHz were achieved from the fabricated PHEMT\\`s of 0.1 m$\mu$ gate length.h.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.1-13
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• 2017

Objective : Soybeans of Canavalia gladiata(CG) and root of Arctium lappa(AL) have been reported to have anti-inflammatory, antioxidant effect. However, the immunoregulatory mechanisms of its combinational prescription remain a matter of considerable debate. In the current study, we investigated whether CG and AL and its combinational prescription(CG+AL) regulate immune system using chronic immobilization-stress mouse model. Methods : C57BL/6J mice fixed for 2 hours into immobilization tube after CG, AL, CG+AL oral administration after 2 hours daily for 21 days. After every experiment has ended the C57BL/6J mice were sacrificed on 22 days. The production of Serotonin and Cortisol, lgA were observed by ELISA method, The proportion of immune cells such as T/B cell and macrophage, NK cell were measured by FACS. Then, Real-time PCR was performed to measure the mRNA expression of Inflammatory cytokines(IL-1beta, IL-6, TNF-a) and T cell activation cytokines(IL-2, IL-10, IFN-gamma, IL-12p35 / p40). Result : When chronic immobilization-stress mouse model were treated with CG+AL(1:4), the expression of mRNA were significantly decreased at the Inflammatory cytokines(IL-1beta, IL-6, TNF-a). While, the levels of mRNA were significantly increased at immune T cell activation cytokines. Additionally, CG+AL(1:4) combinational prescription group enhanced immune cells such as T/B cell and macrophage, NK cell. Furthermore, the Immuno-fluorescence result of brain tissue can confirm that CG+AL(1:4) group significantly increased the BDNF expression. Conclusion : These result suggest that CG+AL(1:4) combinational prescription has Immune System enhancement via stress-mediated immunocyte.

• Journal of The Korean Association For Science Education
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• v.21 no.4
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• pp.697-709
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• 2001

Researchers on conceptual change have been proposed that confronting a cognitive conflict situation would be important for a student to change his/her preexisting conception. There have been reported that there are three different methods of producing a cognitive conflict situation; the first is logical argument(LC), the second is demonstration of an actual phenomenon(DC), and the third is kinesthetic conflict which is a kind of physical experience(EC). In this study, the researcher tried to find out the differences in the conceptual changes by the three different conflict situations. Seventy two high school students were chosen in a high school in Kyungkido, Korea. The students were tested four times; pretest, posttest, one week delayed posttest, and one month delayed posttest. Six different test situations on mechanics were developed for this study. Test item for each situation was developed. Each item consisted of a multiple choice question and explanation of the choice. The result showed a clear differences among the three conflict groups. In general, kinesthetic conflict which is a kind of physical experience(EC) was proved to be the most efficient strategy for the conceptual change; however, logical argument(LC) seemed to be the least efficient. However, the effectiveness was not uniform from situation to situation. Results of some items showed that even the LC was quite good for the conceptual change. Therefore, it seems to be important to develope appropriate method for the target concept.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.19-25
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• 2014

The total production volume has been sharply increased from year 2008 in Gyeongnam province, South Korea by the policy of preservation and promotion of indigenous balloon flower germ lines. In an attempt to assist the Gyeongnam province's policy, in this study, we tried to establish a technique to differentiate the indigenous balloon flower germ lines with those collected within South Korea and China. Our preliminary results indicated that RAPD analyses with five different primers exhibited high frequency of polymorphic DNA bands up to 76.9% and phylogenetic tree indicated that some of the indigenous lines can be easily differentiated with others. However, it was suggested that more advanced techniques such as single nucleotide polymorphic markers need to be developed in particular, by using extra-chromosomal DNA.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.124-124
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• 2003

The successful development of embryos cloned by nuclear transfer (NT)have been dependent on a wide range of known factors including cell cycle of donor and recipient ooplast, oocyte quality, NT procedure and oocyte activation. The present study compared the development of cloned porcine embryos following different activation treatments. Cumulus-oocyte complexes (COCs) were aspirated from 26 mm follicles of slaughterhouse ovaries and cultured for 22 h in NCSU #23 medium supplemented with 10% porcine follicular fluid, 0.57 mM cysteine, 0.5 g/mL LH, 0.5 g/mL FSH and 10 ng/mL EGF. The COCs were further cultured for an additional 22 h in the same medium at $39{\cird}C$ in an atmosphere of 5% $CO_2$ in air, without hormonal supplements. Primary cultures of fibroblasts isolated from a female fetus on day 40 of gestation were established in DMEM + 15% FCS. For nuclear donation, cells at the 5th-6th passage were cultured in DMEM +0.5% FCS for 5 days in order to arrest the cells in G0/Gl. After enucleation, oocytes were reconstructed by transfer of donor cells and fusion with three DC pulses (1.4 KV/cm, 30 sec) in 0.28 M mannitol containing 0.01 mM $CaCl_2$ and 0.01 mM $MgCl_2$. Eggs were then divided into three treatment groups, control (without further treatment, Group 1), eggs cultured in 10 g/ml cycloheximide (CHX) for 5 h (Group 2), and eggs cultured in 1.9 mM 6-dimethylaminopurine (6-DMAP) for 5 h (Group 3). The eggs were then cultured in sets of 30 in 60 I drops of NCSU#23 supplemented with 4mg/ml BSA (essentially fatty acid free) until day 7 at $39{\circ}C$ in a humidified atmosphere of 5% $CO_2$. On day 4 the culture were fed by adding 20 I NCSU #23 supplemented with 10% FBS. Development rates into blastocysts were significantly higher (P<0.05) in Group 3 embryos compared to Group 1 controls ($27.6 \mu 2.7% vs. 20.1 \mu 4.1%$, respectively), but rates did not differ in Group 2 compared to control ($23.8 \mu 5.7%$). Total cell number in Group 3 blastocysts was however significantly higher (P<0.05) than in Groups 1 and 2 ($44.6 \mu 2.4 vs. 19.9 \mu 1.9 and 21.9 \mu 2.1$, respectively). These results suggest that 6-DMAP is more efficient than cycloheximide in the activation of electrically fused NT oocytes during in vitro production of cloned porcine embryos.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.118-126
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• 1986

Vibrio vulnificus is a recently recognized halophilic organism that nay cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be common inhabitant of marine environment. The purpose of this experiment is to investigate the distribution and bacteriological characteristics of V. vulnificus. The strain used in this experiment was isolated from sea water and sea products such as common octopus (Octopus variabilis), ark shell (Anadara broughtonii), blue crab (Ericheir japonica), and sea squirt (Synthia roretzi) collected in Pusan area from July to October in 1985. V. vulnificus was frequently isolated in August when temperature of sea water was around $26^{\circ}C$ and rarely isolated in October when temperature of sea water was around $18.5^{\circ}C$. The distinctive biochemical characteristics of V. vulnificus were ONPG hydrolysis positive and fermented lactose and not grown in peptone water contained $8\%$ NaCl. The optical density at 660 nm of the growth of V. vulnificus was reached maximum level after 8 hours of culture at $35^{\circ}C$ in brain heart infusion broth but that of V. vulnificus was little increased at $15^{\circ}C$ for 14 hours. Optimum temperature and pH for the growth of V. vulnificus were around $35^{\circ}C$ and 8.0. The specific growth rate and the generation time of V. vulnificus isolated from the samples were $1.21\;hr^{-1}$, 34 min at $35^{\circ}C$ and $0.61\;hr^{-1}$, 69 min at $25^{\circ}C$, respectively. V. vulnificus did not grow on eosin-methylene-blue agar, salmonella-shigella agar, deoxycholate agar but grew well on Endo agar, xylose-lysine-deoxycholate agar and hektoen enteric agar. On Endo agar, the colonies of V. vulnificus were red and achieved a diameter of 2 to 4 mm as a feature enabling differentiation of V. vulnificus from other Vibrio spp. V. vulnificus grow well on TCBS agar forming green colonies. V. vulnificus refrigerated at $4^{\circ}C$ exhibited a linear decline of its viablity as 1 log cycle in every 16 hours storage, while V. vulnificus freezed at $-18^{\circ}C$ almost became extinct.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.99-110
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• 2018

In this study, oil of Platycodon grandiflorum seeds was prepared using supercritical carbon dioxide extraction (SCE) and its physicochemical indices as a new edible oil were investigated. Compared to Soxhlet solvent extraction, SCE under the condition of 6,000 psi at $40^{\circ}C$ produced more oil, especially from the roasted seeds to 32.7%. TLC analysis showed triacylglycerols accounted for most of the oil obtained from roasted Platycodon grandiflorum seeds by SCE similarly to commercial soybean oil or perilla seeds oil. The oil had highly unsaturated lipid with considerable amount of linoleic acid(73.27%) much more than two commercial oils followed by oleic acid(13.16%). Physicochemical properties of the oil were as follows; specific gravity, 0.92; dynamic viscosity, 45.37 cP; refractive index, 1.48; color, L=47.30, a=-3.69, b=25.72; iodine value, 141.57 g $I_2/100g$ oil; saponification value, 191.21 mg of KOH/g of oil; acid value, 2.60 mg of KOH/g of oil. Among those, refractive index, viscosity and iodine value, which were related to unsaturation degree of lipid, were ranged between those of two commercial oils. The oxidation stability of oil(2.03 hr) was also ranged between less stable perilla seeds oil(1.79 hr) and more stable soybean oil(2.94 hr) based on the induction time measured by Rancimat assay. In addition to extraction yield increase, seeds roasting provided further benefits such as reductions of cholesterol ester content and acid value without change in fatty acid composition. In conclusion, oil was extracted from the roasted Platycodon grandiflorum seeds at high yield by supercritical carbon dioxide and it seemed to have proper characteristics as a edible oil.