• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.726-729
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• 2000

Though L $a_{1+x}$S $r_{2-x}$M $n_2$ $O_{7}$ n=2 R-P phases have been well known to have CMR effect, it was generally believed that n=1 phase was insulating. But recently monolayered perovskite $Ca_{2-x}$L $n_{x}$Mn $O_4$phase has been reported to show magnetoresistance. In this study, layered perovskite $Ca_{2-x}$L $n_{x}$Mn $O_4$ (x=0, 0.5, Ln=Pr, Nd, Sm, Gd) phases were synthesized by solid state reaction and their structures were refined by Rietveld method. The space groups of $Ca_2$Mn $O_4$, N $d_{0.5}$C $a_{1.5}$Mn $O_4$phases were refined as C2cb and Fmmm, respectively.y.ely.y.y.y.y.y.y.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.26-26
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• 2020

Daphne L. (Thymelaceae) comprises about 95 species distributing worldwide from N Africa, N India, SE Asia to E Asia and the coast of the Mediterranean of Europe. In Korea, five species of this genus have been described. In this study, we included four species (D. genkwa, D. pseudomezereum, D. kiusiana, D. jejudoensis) from Korea, excluding cultivated D. odora. The morphological characters through local surveys and the re-classification of the specimens collected in the Korea National Herbarium (KH) were carried out and distribution maps for each taxon were also prepared. The major characters include habit, trichomes in winter bud, leaf, and twig, phyllotaxis, inflorescence, size of calyx lobe and trichomes in the calyx tube, etc. The distribution map showed that D. genkwa is mainly distributed in the coastal area of Hwanghaenam-do, Pyeongannam-do, Jeollabuk-do and Jeollanam-do, whereas D. pseudomezereum is distributed in the limestone zone of Gangwon-do, Jeollabuk-do, and Gyeongsangbuk-do. Similarly, D. kiusiana is mostly found in Jeollanam-do, Gyeongsangnam-do, and Jeju-do. In addition, D. jejudoensis is known to be distributed in forests of Murueng, Andeok, and Seonheul-ri in Jeju-do, but recently, new habitat is discovered in the island forest areas of Jeollanam-do. However, some of these individuals showed the characteristics of D. kiusiana, thus before come to any conclusion detailed taxonomic review of D. jejudoensis and D. kiusiana is required.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.281-287
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• 1999

Codonopsis lanceolata ("Deoduck" in Korea) is a perennial herb, and belongs to family, Campanulaceae. Its taproot is used a good source of a wild vegetable as well as an herbaceous medicine. In this study, to develop a bialaphos-resistant transgenic Codonopsis, seed germination mechanism and somatic embryogenesis of the plant were investigated, and Agrobacterium-mediated transformation with bar gene encoding phosphinothricin acetyltransferase (PAT) was performed. Attempt were made to regenerate plant from cells via somatic embryogenesis. When the cotyledons, nodes and leaf disks were cultured on MS medium containing 2,4-D and zeatin, embryogenic calli were induced. Upon transferring the somatic embryos to N6 solid medium without plant growth regulators, they developed into plantlets under continuous illumination. All plants were dead on MS basal medium containing 10 mg/L phosphinothricin (PPT) and Basta, respectively. The explants did not produce calli in the medium containing 200 mg/L kanamycin. The explants were cocultured with Agrobacterium tumefaciens for 2 days, and transformants were selected in MS basal medium containing 1.0 mg/L 2,4-D, 100 mg/L kanamycin and 500 mg/L carbenicillin. After the selection, embryogenic calli were induced and then somatic embryos were produced by subsequent subculturing. The somatic embryos were germiated on N6 basal medium containing 200 mg/L kanamycin and 500 mg/L carbenicillin. PCR analysis showed that nptII and bar genes were introduced in the Deoduck transformants. After the confirmation of bar gene expression in RNA and protein level, the transgenic Deoduck will be used to study the genetics of filial generation with the herbicide control gene, bar.gene, bar.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1092-1096
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• 2020

YjiC, a glycosyltransferase from Bacillus licheniformis, is a well-known versatile enzyme for glycosylation of diverse substrates. Although a number of O-glycosylated products have been produced using YjiC, no report has been updated for nucleophilic N-, S-, and C- glycosylation. Here, we report the additional functional capacity of YjiC for nucleophilic N- and S- glycosylation using a broad substrate spectrum including UDP-α-D-glucose, UDP-N-acetyl glucosamine, UDP-N-acetylgalactosamine, UDP-α-D-glucuronic acid, TDP-α-L-rhamnose, TDP-α-D-viosamine, and GDP-α-L-fucose as donor and various amine and thiol groups containing natural products as acceptor substrates. The results revealed YjiC as a promiscuous enzyme for conjugating diverse sugars at amine and thiol functional groups of small molecules applicable for generating glycofunctionalized chemical diversity libraries. The glycosylated products were analyzed using HPLC and LC/MS and compared with previous reports.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.71-77
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• 2007

The antioxidant properties of twelve phenolic compounds, including matairesinol 4'-O-$\beta$-D-glucoside, 8'-hydroxyarctigenin 4'-O-$\beta$-D-glucoside, matairesinol, 8'-hydroxyarctigenin, N-feruloylserotonin 5-O-$\beta$-D-glucoside, N-(p-coumaroyl)-serotonin-5-O-$\beta$-D-glucoside, N-feruloylserotonin, N-(p-coumaroyl)serotonin, luteolin 7-O-$\beta$-D-glucoside, luteolin, acacetin 7-O-$\beta$-glucuronide, and acacetin, isolated from defatted safflower (Carthamus tinctorius L.) seeds were evaluated with regard to the DPPH, superoxide and hydroxyl radicals. Additionally, levels of phenolic compounds were determined by HPLC in two cultivars of safflower seeds. Among them, four serotonin derivatives showed potent DPPH ($IC_{50}=10.83-21.75\;{\mu}M$) and hydroxyl ($IC_{50}=75.93-374.63\;{\mu}M$) radical scavenging activities, and their activities were significantly stronger than that of ${\alpha}-tocopherol$. Four flavonoids ($IC_{50}=170.65-275.83\;{\mu}M$) and four lignans ($IC_{50}=114.22-406.10\;{\mu}M$) exhibited significant superoxide and hydroxyl radical scavenging activities, respectively, whereas these compounds contained less activity toward the DPPH and hydroxyl radicals than serotonin derivatives. The levels of serotonin derivatives, lignans and flavonoids in safflower seeds of two cultivars ranged from 49.30 to 260.40, 3.72 to 158.90, and 11.72 to 214.97 mg% (dry base), respectively. Of the two cultivars, 'Cheongsu' had somewthat higher concentrations of phenolic compounds than 'Uisan'. These results suggest that phenolic compounds in safflower seeds may playa role as protective phytochemical antioxidants against reactive oxygen-mediated pathological diseases.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.73-80
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• 2003

Useful Dianthus species were collected and selected from two native and seven foreign species distributed in Gangwon province. For in vitro breeding,. callus was induced from the explants of apical meristem, leaf, stem and the in vitro adventitious shoots on MS basal medium with 2.0 mg/L 2,4-D and 0.5 mg/L BA at 27$^{\circ}C$ under continuous light. After 3 weeks of culture, calli initiated the most highly from the leaf explants of D. chinensis Organogenic calli were able to be selected from the adventitious shoot-derived calli. For shoot regeneration, these organogenic calli were cultured on MS medium with the combination of 0.1 mg/L NAA＋1.0 mg/L BA under continuous light. Multiple shoots were proliferated with low frequency (about 30%) from those adventitious shootderived calli. Also, shoots initiated directly from the adventitious shoot explants without callus formation at high frequency of 52% when cultured on N6 medium containing 0.1 mg/L NAA and 1.0 mg/L BA in D. gratianopol. Multiple shoots and plantlets grew well and rooted on MS medium supplemented with 0.1 mg/L NAA. Regenerants with well-developed roots were transferred to 8-cm pots containing vermiculite at 85% relative humidity and 27$^{\circ}C$ These plantlets were acclimatized in artificial soil mixture and transferred to the greenhouse for flowering with normal phenotypes. M28 Mutant line was selected with white flowers from 0.03M EMS-treated organogenic calli derived from in vitro adventitious shoot explants of D. chinensis and set seeds.

• Polymer(Korea)
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• v.35 no.1
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• pp.52-59
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• 2011

L-PLA or D-PLA was synthesized in bulk at $140^{\circ}C$ by ring opening polymerization(ROP) of L-lactide or D-lactide as a monomer using tin(II) octoate and lauryl alcohol as a catalyst and an initiator with changing the amounts of catalyst(0.25~1.0 wt%) and initiator(0.l~0.5 wt%). And stereocomplex-PLA was prepared by L-PLA/D-PLA having a wide range of molecular weight(30000~90000 g/mol) and L-PLA/D-PLA blends having different mixing ratio ($X_D$). The melting temperature. thermal degradation temperature and thermal stability of stereocomplex-PLA were higher than those of homopolymers(L-PLA, D-PLA). We supposed that these improvements arose from a strong interaction between L-PLA and D-PLA. The improved mechanical properties and changes in morphology of LPLA/D-PLA blends were compared to those of homopolymers(L-PLA, D-PLA).

• ALGAE
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• v.31 no.3
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• pp.257-266
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• 2016

Nitrogen is one of the most critical nutrients affecting cell growth and biochemical composition of microalgae, ultimately determining the lipid or carbohydrate productivity for biofuels. In order to investigate the effect of nitrogen sources on the cell growth and biochemical composition of the marine microalga Tetraselmis sp., nine different N sources, including NaNO₃, KNO₃, NH₄NO₃, NH₄HCO₃, NH₄Cl, CH₃COONH₄, urea, glycine, and yeast extract were compared at the given concentration of 8.82 mM. Higher biomass concentration was achieved under organic nitrogen sources, such as yeast extract (2.23 g L⁻¹) and glycine (1.62 g L⁻¹), compared to nitrate- (1.45 g L⁻¹) or ammonium-N (0.98 g L⁻¹). All ammonium sources showed an inhibition of cell growth, but accumulated higher lipids, showing a maximum content of 28.3% in ammonium bicarbonate. When Tetraselmis sp. was cultivated using yeast extract, the highest lipid productivity of 36.0 mg L⁻¹ d⁻¹ was achieved, followed by glycine 21.5 mg L⁻¹ d⁻¹ and nitrate 19.9 mg L⁻¹ d⁻¹. Ammonium bicarbonate resulted in the lowest lipid productivity of 14.4 mg L⁻¹ d⁻¹. The major fatty acids in Tetraselmis sp. were palmitic, oleic, linoleic and linolenic acids, regardless of the nutritional compositions, indicating the suitability of this species for biodiesel production.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.695-701
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• 2011

The study was carried out to investigate the effect of lighting regimes on performance and meat quality of broiler. A total of 912 chicks was divided into 2 groups with male (3 replications/group, 34 heads/replication) and female (3 replications/group, 42 heads/replication). Treatments were control (C, natural lighting), T1 treatment (24L), and T2 treatment (1~2d, 24L; 2~4d, 23L+1D; 4~16d, 16L+8D; 16~21d, 18L+6D; 21~42d, 23L+1D) by lighting regimes. Lysine content of male chicken meats at T2 treatment was lower compared to that of other treatments (p<0.05). There was no significant difference in all nonessential amino acid (AA) among treatments. Methionine content of female chicken meats at T2 treatment was lower compared to that of other treatments (p<0.05). The rate of C16:0, C16:1n7, and C18:1n9 of male chicken meat at T2 treatment was higher than that of other treatments (p<0.05), while C18:2n6 was lower at T2 treatment than other treatment (p<0.05). Mono-saturated fatty acid was the highest at T2 treatment, however, polysaturated fatty acid was the lowest at that treatment (p<0.05). There was no considerable difference in fatty acid composition of female chicken meat among treatments. Finally, lighting regime didn' affect on amino acid and fatty acid contents, and used possibly on energy reduction.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.216-221
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• 2016

This study was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 35% paraformaldehyde against Salmonella Typhimurium (S. Typhimurium). In this study, the efficacy test of a fumigant against S. Typhimurium was carried out according to French standard NF T 72-281. The S. Typhimurium working culture suspension number (N value), all bacteria numbers on the carriers exposed to the fumigant (n1, n2, and n3), the number of bacterial suspensions by the pour plate method (N1), the number of bacterial suspensions by the filter membrane method (N2), and the mean number of bacteria recovered on the control carriers (T value), were obtained from the preliminary test. In addition, the reduction number of S. Typhimurium exposed to the fumigant (d value) was calculated using the T value, the mean number of bacteria in the recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). The N value was $5.5{\times}10^8$ colony forming units (CFU)/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, the T value was $3.5{\times}10^6CFU/carrier$. In terms of the bactericidal effect of the fumigant, the d value was 5.25. According to the French standard for fumigants, the d value for an effective bactericidal fumigant should be greater than 5. The results indicated that the fumigant containing 35% paraformaldehyde had an efficient bactericidal activity against S. Typhimurium, and, therefore, can be used to disinfect food materials and kitchen appliances contaminated with foodborne bacteria.