• Journal of Korean Dental Science
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• v.11 no.2
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• pp.43-56
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• 2018

Purpose: The purpose of this study was to assess the adhesiveness and cytotoxicity of 3, 4-dihydroxyphenylalanine (DOPA), and to evaluate the role of collagen membrane with DOPA in the guided bone regeneration. Materials and Methods: Peel resistance and cell cytotoxicity test were performed. Four defect types in nine rabbit calvaria were randomly allocated: i) control, ii) membrane, iii) deproteinized porcine bone mineral (DPBM) covered by membrane with DOPA, and iv) DPBM covered by membrane with cyanoacrylate. Animals were sacrificed at 2 (n=4) and 8 weeks (n=5) for microcomputed tomography and histomorphometric analysis. DOPA showed low peel resistance but high cell viability. Result: Cyanoacrylate and DOPA groups showed significantly higher mineralized tissue volume (MTV) compared to control and membrane groups at 2 weeks (P<0.05). At 8 weeks, DOPA group showed the highest MTV. Significantly higher new bone area was found in DOPA group at 8 weeks (P<0.05). Bone formation increased from 2 to 8 weeks in DOPA group (P<0.05). Conclusion: DOPA showed high cell viability and in vivo study revealed predictable performance in bone regeneration.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.321-336
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• 2018

Sesame (Sesamum indicum L.) is an important oilseed crop grown in tropical and subtropical areas. The objective of this study was to investigate the genetic relationships among 129 sesame landraces and cultivars using simple sequence repeat (SSR) markers. Out of 70 SSRs, 23 were found to be informative and produced 157 alleles. The number of alleles per locus ranged from 3 - 14, whereas polymorphic information content ranged from 0.33 - 0.86. A distance-based phylogenetic analysis revealed two major and six minor clusters. The population structure analysis using a Bayesian model-based program in STRUCTURE 2.3.4 divided 129 sesame accessions into three major populations (K = 3). Based on pairwise comparison estimates, Pop1 was observed to be genetically close to Pop2 with $F_{ST}$ value of 0.15, while Pop2 and Pop3 were genetically closest with $F_{ST}$ value of 0.08. Analysis of molecular variance revealed a high percentage of variability among individuals within populations (85.84%) than among the populations (14.16%). Similarly, a high variance was observed among the individuals within the country of origins (90.45%) than between the countries of origins. The grouping of genotypes in clusters was not related to their geographic origin indicating considerable gene flow among sesame genotypes across the selected geographic regions. The SSR markers used in the present study were able to distinguish closely linked sesame genotypes, thereby showing their usefulness in assessing the potentially important source of genetic variation. These markers can be used for future sesame varietal classification, conservation, and other breeding purposes.

• Advances in concrete construction
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• v.6 no.6
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• pp.561-583
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• 2018

A variety of polycarboxylate ether (PCE)-based superplasticizers are commercially available. Their influence on the rheological retention and slump loss in respect of concrete differ considerably. Fluidity and slump loss are the cardinal features responsible for the quality of concrete. These are related to the dispersion of cement particles and the hydration process which are greatly influenced by type of polycarboxylate ether (PCE)-based superplasticizers. On the backdrop of relatively less studies in the context of rheological retention of high strength self-consolidating concrete (HS-SCC), the experimental investigations were carried out aiming at quantifying the effect of the six different PCE polymers (PCE 1-6) on the rheological retention of HS-SCC mixes containing two types of Ordinary Portland Cements (OPC) and unwashed crushed sand as the fine aggregate. The tests that were carried out included $T_{500}$, V-Funnel, yield stress and viscosity retention tests. The supplementary cementitious materials such as fly ash (FA) and micro-silica (MS) were also used in ternary blend keeping the mix paste volume and flow of concrete constant. Low water to binder ratio was used. The results reveal that not only the PCEs of different polymer groups behave differently, but even the PCEs of same polymer groups also behave differently. The study also indicates that the HS-SCC mixes containing PCE 6 and PCE 5 performed better as compared to the mixes containing PCE 1, PCE 2, PCE 3 and PCE 4 in respect of all the rheological tests. The PCE 6 is a new class of chemical admixtures known as Polyaryl Ether (PAE) developed by BASF to provide better rheological properties in even in HS-SCC mixes at low water to binder mix. In the present study, the PCE 6, is found to help not only in reduction in the plastic viscosity and yield stress, but also provide good rheological retention over the period of 180 minutes. Further, the early compressive strength properties (one day compressive strength) highly depend on the type of PCE polymer. The side chain length of PCE polymer and the fineness of the cement considerably affect the early strength gain.

• Journal of IKEEE
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• v.23 no.2
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• pp.425-430
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• 2019

This work describes the design and characterization of a X-band power amplifier (PA) monolithic microwave integrated circuit (MMIC) using a $0.25{\mu}m$ gate length gallium nitride (GaN) high electron mobility transistor (HEMT) technology. The developed X-band power amplifier MMIC has small signal gain of over 22.7 dB and saturated output power of 43.02 dBm (20.04 W) over the entire band of 9 to 10 GHz. Maximum saturated output power is a 43.84 dBm (24.21 W) at 9.5 GHz. Its power added efficiency (PAE) is 41.0~51.24% and the chip dimensions are $3.7mm{\times}2.3mm$, generating the output power density of $2.84W/mm^2$. The developed GaN power amplifier MMIC is expected to be applied in a variety of X-band radar applications.

• Journal of IKEEE
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• v.24 no.4
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• pp.1093-1097
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• 2020

This work describes the design and characterization of a Ku-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) for satellite communication applications. The device technology used relies on 0.25 ㎛ gate length gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (PHEMT) of wireless information networking (WIN) semiconductor foundry. The developed Ku-band PHEMT MMIC power amplifier has a small-signal gain of 22.2~23.1 dB and saturated output power of 34.8~35.4 dBm over the entire band of 13.75 to 14.5 GHz. Maximum saturated output power is a 35.4 dBm (3.47 W) at 13.75 GHz. Its power added efficiency (PAE) is 30.6~37.83% and the chip dimensions are 4.4 mm×1.9 mm. The developed 3 W PHEMT MMIC power amplifier is expected to be applied in a variety of Ku-band satellite communication applications.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.747-754
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• 2020

This study was conducted to evaluate the effect of high-oleate and normal-oleate peanut consumption on adipose mass and serum lipids in obese-induced C57BL/6J mice. After four weeks of the high-fat diet, mice were randomly divided into six groups: normal control (NC) diet, high-fat control (HFC) diet, high-oleate peanut-seed (HOPS) diet, normal-oleate peanut-seed (NOPS) diet, high-oleate peanut-oil (HOPO) diet, and olive-oil (OO) diet. After four weeks, all four experimental diet groups showed significantly lower body weight and epididymal fat weight than HFC group. In four experimental diet groups, serum triglycerides (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly lower, and high-density lipoprotein cholesterol (HDL-C) was significantly higher than HFC group. TG was significantly decreased in HOPS group (92.1±1.2 mg/dL) than NOPS group (101.7±5.3 mg/dL, p<0.05). Similarly, LDL-C was significantly lower in HOPS group (66.1±2.8 mg/dL) than NOPS (76.9±1.5 mg/dL, p<0.05), on the other hand, HDL-C indicated a significant elevation in HOPS (50.5±2.1 mg/dL) than NOPS group (45.2±1.6 mg/dL, p<0.05). This result suggests that the consumption of high-oleate peanut has a favorable effect on the plasma lipid profile.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.235-241
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• 2017

Generally, peanuts are classified as high-fat foods as they possess high proportions of fatty acids. This study compared lipid constituents and properties between normal and high-oleic peanuts. Gas Chromatography-Flame Ionization Detector (GC-FID) analyses revealed that the fatty acid levels were significantly different between the normal and higholeic peanuts (p<0.05). Eight fatty acids were identified in the samples, including palmitic (C16:0), stearic (C18:0), oleic (C18:1, n9), linoleic (C18:2, n6), arachidic (C20:0), gondoic (C20:1, n9), behenic (C22:0), and lignoceric (C24:0) acids. Four tocopherol homologs were detected, and ${\alpha}$- and ${\gamma}$-tocopherols were the predominant ones. Tocopherols were rapidly decomposed during 25 day storage at $80^{\circ}C$. The main identified phytosterols were beta-sitosterol, ${\Delta}^5$-avenasterol, campesterol, and stigmasterol. Acid and peroxide values indicated that high-oleic peanuts have better oxidative stability than normal peanuts. These results can serve as the basis for the use of peanuts in the food industry.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.121-128
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• 2010

This paper presents a design of a 100 W high-efficiency power amplifier, whose operational frequency band expands from 30 to 512 MHz, using negative feedback network, push-pull structure, broadband RF choke, and transmission line transformer for balun configuration. The push-pull amplifier has been tuned for higher output power using a shunt capacitor as a matching component at its load especially for high-frequency region. The implemented power amplifier exhibited a very flat power gain of $18.34{\pm}0.9\;dB$ throughout the operating frequency band and very high power-added efficiency(PAE) of greater than 40% at an output power of 100 W. It also showed second- and third-harmonic distortion levels of below -34 dBc and -12 dBc, respectively, through the entire operating frequency band.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.507-514
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• 2010

Peanut(Arachis hypogaea L.) is one of the major oilseed crops. The peanut oil consists of palmitic, oleic and linoleic acids, which are present at levels of 10%, 36-67% and 15-43%, respectively. High oleate mutant of peanut F435 contains 80% oleate and as little as 2% linoleate in seed oil. Previous study indicated that delta 12 fatty acid desaturase is a major enzyme controlling the oleate content in seeds of oilseed crops. F435 sequence alignment of their coding regions disclosed that an extra A(adenine) was inserted at the position +2,823 bp of delta 12 fatty acid desaturase gene. This study was to develop molecular marker (SNP marker) co-segregating with the high oleate trait. Chopyeong ${\times}$ F435 $F_2$ 41 population were investigated using molecular marker and fatty acid assay (NIR and gas chromatography). Finally, this marker segregates Chopyeong type 26 lines, heterotype 9 lines and F435 type 6 lines. These results in our study suggested that SNP marker conform fatty acid assay.

• Journal of the korean society of oceanography
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• v.34 no.1
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• pp.49-57
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• 1999

A red tide organism, Amphidinium carterae was incubated under different iron/chelator and nitrate concentrations to investigate the factors controlling the growth. The chelation capacity played a critical role in regulating the nitrate reductase (NR) activity and in vivo fluorescence of this organism. However, there was a significant difference between the NR activity and in vivo fluorescence in response to trace metals and chelator treatments. In vivo fluorescence was the highest in FeEDTA 10 ${\mu}$M treatments and the lowest in DTPA 10 ${\mu}$M treatments. This indicates that the availability of the trace metal is important in regulating the in vivo fluorescence of this photosynthetic microalgae In contrast, NR activity showed the highest values in trace metal enriched treatments, and trace metal + DTPA treatments showed fairly high NR activities. This suggests that DTPA treatment did not hinder the NR activity as much as it did in vivo fluorescence. In vivo fluorescence and NR activity increased with nitrate concentration of up to 50 ${\mu}$M and remained relatively constant or the rate of increase decreased above that concentration, indicating that initial nitrate concentration of higher than a certain level would not accelerate the growth of A. carterae. Further investigation is needed to elucidate the reason for the difference in timing sequence between the NR and in vivo fluorescence in response to different metal treatments and chelation capacity.