• Applied Biological Chemistry
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• v.45 no.3
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• pp.129-133
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• 2002

Suppression of nitrate accumulation in spinach and lettuce through foliar application of chitosan formula containing micronutrients is related with the increase of the nitrate reductase (NR) activity. If NR in spinach were highly expressed to increase the assimilatory activity, nitrate content could be reduced. For this, NR cDNA was cloned from the isolated mRNAs of spinach using reverse transcriptase-PCR. Nucleotide sequence of cloned spinach NR cDNA showed highly deduced amino acid sequence identity ($71{\sim}82%$) with other known plant NR genes. Only two nucleotide-base differences were observed in the cloned NR cDNA compared with that of the published spinach NR cDNA.

• Proceedings of the Korean Nutrition Society Conference
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• 1998.11a
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• pp.74-74
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• 1998

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.654-660
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• 1999

Folate, a precursor of the coenzyme tetrahydrofolate, plays an important role in DNA replication and cell proliferation, and thus could influence rapidly proliferating immune cells such as leukocytes and splenocytes. The effects of dietary folate on folate concentrations of plasma, thymus, spleen and leukocytes were investigated in rats. The animals were raised for 6 weeks on semipurifed experimental diets containing 0mg, 2mg, 4mg, 8mg folate/kg diet. Folate concentrations were determined microbiologically using Lactobacillus casei(ATCC 7469), and DNA strand breaks produced by alkaline treatment were analyzed fluorometrically. When compared to folate adequate diet, the folate deficient diet(0mg folate/kg diet) resulted in lowest folate levels in plasma, thymus, spleen and leukocytes, and the highest DNA strand breaks in spleen cells and leukocytes. Dietary folate levels significantly increased folate concentrations of immune tissues, leukocytes, and the plasma in a dose dependent manner, folate concentrations being highest with a diet providing 8mg folate/kg diet. The percentages of the double strand DNA remaining in the splenocytes and leukocytes after alkaline treatment were significantly increased with higher amounts of dietary folate in a dose dependent manner. Folate intakes of 8mg than 4mg/kg diet was found to be more effective in the prevention of DNA strand breaks. The results of this study suggest that increased folate above the requirement level could improve DNA stabilities in immune cells.

• Polymer(Korea)
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• v.29 no.3
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• pp.277-281
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• 2005

Recently, various curriers prepared by the modification both cationic polymers and liposomes have been examined. In this work, we prepared the lipid with polyethylenimine (PEI) to investigate the possibility as effective DNA carrier. Cationic lipid (PEI-DSPE) was synthesized by the reaction of PEI and 1,2-diacyl-sn-glycero-3-phosphoetha-nolamine (DSPE). The liposomes were prepared by the concenoation changes of PEI-DSPE for a mixture of 1,2-disteanyl-sn-glycero-3-phosphocholine (DSPC), L-$\alpha$-phosphatidylcholine, hydrogenated (HSPC) and cholesterol (CHOL). Particle size decreased as PEI-DSPE concentration increased. In addition, the charge of liposome surface increased to positive value according to increasing the relative of PEI-DSPE concentration. The complexation of DNA was confirmed by gel retardation assay and fluorescence measurement. The surface charge of liposome/DNA complexes increased as the liposome concentration or surface charge of liposome increased. In conclusion, we confirmed that the prepared liposomes have the possibility as a DNA carrier.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.37-45
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• 1975

The present study was ,conducted to evaluate the effects of condensed phosphates on the refeezing damage of Alaska pollack muscle. The fillets were dipped in such solution as 5 and $10\%$ sodium polyphosphate, 1 and $5\%$ mixture of sodium polyphosphate and sodium pyrophosphate (1:1, w/w) for 1 and 5 minutes, respectively, before refreezing. And fillets were frozen at $27^{\circ}C\~28^{\circ}C$ and stored for 15 days at $-18^{\circ}\~-20^{\circ}$. The degree of denaturation was estimated by determining amounts of drip relased, content of total solids, nitrogen, and DNA in the drip an cooking-weight-loss. Phosphorus absorbed in the muscle was also determined. Phosphorus absorbed in the fillets treated with loft solution of sodium polyphosphate for 5 minutes amounted to 101 mg/100g muscle as $P_2O_5$. The absorption was dependent on tile concentration of treating solution rather than on the dipping time. The increase of phosphorus absorption seemed to affect to reduction of drip. Among the treating conditions, $10\%$, 5 minutes and $10\%$ 1 minute with sodium polyphosphate appeared most effective ones on drip reduction. The effect of $5\%$, minutes with the mixture of sodium polyphosphate and sodium pyrophosphate did not show so benefitable effect in refrozen fillets. As a tendency total solids, nitrogen, and DNA in tile drip varied proportionally to the amount of drip released. And the content of DNA was lower than the amount. Treatment, at higher the concentration and longer the dipping time, resulted in the lower cooking-weight-loss and the better quality on organoleptic test of thawed fillets.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.198-203
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• 2013

Herein we analyzed the nuclear DNA content and the histological characteristics of the triploid of the 'Hyunsasi' (Populus alba ${\times}$ P. glandulosa $F_1$) which were developed for biomass production and molecular breeding research. The flow cytometric analysis showed that the nuclear DNA content of the 3 triploids were 1.6 times greater than those of the diploid. In terms of histological characteristics, the cross-section area of the stem of 'Line-18' was 1.6 times larger than that of the diploid. The area of pith, and cortex and phloem of the stem of 'Line-18' was also 1.6 and 2.0 times larger than that of the diploid, respectively. Moreover, the length and area of guard cell of 'Line-18' was 1.2 times larger than that of the diploid. These results helps to understand the cytological characteristics of the triploid poplar clones, and further investigations in the growth rate and wood properties of the triploids growing in the field will determine whether the triploid poplars are good candidates for molecular breeding programs and for the improvement of industrial biomass productivity.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.474-481
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• 2009

The purpose of this study was to identify the quantitative trait loci (QTL) associated with gel consistency (GC), and to evaluate the relationships between GC and physico-chemical properties related to eating quality in rice. A total of 120 doubled haploid (DH) lines derived from a cross between 'Samgang' and 'Nagdong' and 26 varieties were used for this study. The 120 DH lines were divided into four groups, soft (61~100 mm), medium (41~60 mm), hard (26~40 mm) and whole population, according to the gel length. A negative correlation between GC and amylose content was observed only in the soft group. The GC negatively correlated with lipid content in the medium, and the whole population, but positively correlated with lipid content in the soft group. The positive correlation between GC and protein content was observed in the soft group, while negative correlations were observed in the medium group and the whole population. Two significant QTLs regarding GC were detected on chromosomes 4 and 11. They collectively explained 23% of phenotypic variation with LOD score of 3.1 and 2.9, respectively. The DNA markers of S4026 and RM287 were tightly linked to GC in the DH population and 26 varieties, respectively.

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.178-182
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• 2006

This study was conducted to investigate the variation in sequence, the base composition and the sequence similarity of 18S rDNA (18S ribosomal RNA coding region) in the 10 Polygonatum spp. collections. The entire 18S rDNA region of 10 Polygonatum spp. collections ranged from 913 bp to 914 bp. There were 8 variable sites in the entire 18S region, and they were attributable to nucleotide substitution and deletion. $T{\rightarrow}C$ transition happened in 4 sites, and $A{\rightarrow}G$ transition happened in 1 site. $C{\rightarrow}A$ transversion happened in 1 site, and deletion happened in 2 sites. Transition rates were five times that of transversion. Base compositions of 18S rDNA were $23.09{\sim}23.33%$ in adenine, $23.33{\sim}23.52%$ in guanine, $25.60{\sim}25.85%$ in thymine and $27.38{\sim}27.79%$ in cytosine. The A + T content of 18S rDNA of 10 Polygonatum spp. collections averages 48.99%, ranging from 48.80% to 49.18%, and the G + C content averages 51.01%, ranging from 50.82% to 51.20%. Pairwise sequence comparisons indicated that 18S rDNA sequence similarity ranged from 99.7% to 100%.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.101-108
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• 2006

YNB54 strain which shows inhibitory activities specific to the plant pathogenic Phytophthora sp. on potato dextrose agar medium was screened among lots of strains isolated from Korean soils. To identify taxonomy of the Phytophthora specific antagonistic bacteria YNB54, 165 rDNA sequence, MIDI fatty acid composition, DNA-DNA hybridization, GC content, and commercial multitest systems such as API 20E and Biolog GN were performed. Results of commercial kits including lots of biochemical and physiological reactions showed that this strain was closely related to taxa including Enterobacter cloacae and Enterobacter cancerogenus species than other genera(Citerobacter Klebsiella, Leclercia). Also, analysis of its MIDI, G+C contents, and DNA-DNA hybridization suggests that this strain was more similiar to the Genus Enterobacter than other genera (Citerobacter Klebsiella, Leclercia). This strain was potentially identified as Enterobacter sp. by these results. But our 16S ribosomal DNA sequences (rDNA) analysis confirmed that it was more closely related to the cluster of Citerobacter freundii ATCC 29935 than any other Enterobacter species. In the absence of defined phylogenetic critia for delineating genera, the results observed with Citrobacter and Enterobacter species suggest that further studies are needed to clarify their relationships. This investigation demonstrates that YNB54 strain is genetically diverse and potentially more taxonomically complex than hitherto realized. Further study is necessary to confirm their taxonomic positions.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.82-82
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• 1993

허혈-재관류손상 심근세포의 DNA에서 8-hydroxydeoxyguanosine (8-OHdG) 생성을 검토하였다. 흰쥐 적출심장의 Langendorff 관류 표본에서 대동맥 차단에 의한 60분 허혈후 산소가 포화된 Kredb-Henseleit용액으로 30분간 재관류 하므로서 허혈-재관류 손상을 유도하였다. 재관류 후 심근세포에서 DNA를 추출하고 HPLC(EC detector)를 이용하여 8-OHdG를 측정하였다. 실험결과 허혈-재관류 심근세포의 DNA에서 8-OHdG 함량이 증가하였으며 이는 $O_2$ 제거물질인 superoxide dismutase와 OH 제거물질인 mannitol에 의하여 방지되었다. Xanthine oxidase외 경쟁적 길항약인 allopurinol도 8-OHdG 생성을 억제하였으며 단백분해효소 억제제인 phenylsulfonylfluoride 그리고 관류액에서 칼슘의 제거 또한 허혈-재관류 심근 DNA의 생성을 방지하였다. 이상의 결과 허혈심근의 재관류시 8-OHdG 생성이 증가하며 이는 재관류 손상과 같은 산화성 심근손상을 평가하는 좋은 Index가 될 수 있을 것으로 여겨진다.