• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.247-252
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• 2002

“DK 537”has been selected by forage crop breeding team at the National Livestock Research Institute(NLRI), RDA and has been determined by the Deliberative Council of the National Agricultural Cooperative Federation(NACF) in 2002, as a new recommended hybrid which is early maturing, good quality and hi호 yield of corn for silage. The characteristics of this hybrid are as follows ; 1. The seed coat is yellow and the mean of tasseling date is 5th of July, included in early maturing hybrid which is one day delayed than check cultivar, DK 501. The culm length is 246cm. It is resistant to lodging because of its low height from surface to ear. 2. DK 537 shows resistance to H. maydis and Maize Black-Streaked Dwarf Virus(MBSDV). It also shows strength to corn borer as much as DK 501 does. 3. Fresh yield. dry matter yield. and TDN per a ha are 50 tons, 16.9 tons, and 11.4 tons respectively. which are almost same yielding level of DK 501. Its percent ear to total dry matter is 50.8% at the same time. Through all these tests, we could make sure at DK 537 hybrid will be recommended as good forage crop.

• Toxicological Research
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• v.14 no.3
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• pp.427-433
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• 1998

The acute and genetic toxicity of DK1002 was subjected in this study. DK1002 which is a morphine-like new drug candidate synthesized by Dong-Kook Pharmaceutical Co. Ltd. is now under developing as a analgesics that have better drug efficacy and least addictive property. In acute toxicity study, the 50% lethal doses ($LD_{50}$) of DK1002 were determined as>2000mg/kg (p.o.), 237.0mg/kg(i.p.), 57.5mg/kg(i.v.), and 1266.9mg/kg (s.c.). And also, to study the genotoxicity of DK1002, we performed bacterial reversion assay with Salmonella typhimurium TA98, TA100, TA1535, and TA1537, and in vitro chromosomal aberration assay with Chinese hamster lung cells in the presence and absence of S-9 metabolic activation system. In vivo micronucleus assay using mouse bone marrow cells was also performed. From these results, DK1002 was revealed nonmutagenic potential in S. typhimurium TA98, TA100, TA1535, and TA537 both in the absence and presecne of metablic activation system. No clastogenicity of DK1002 was observed in chromosomal aberration assay in vitro as well as in micronucleus assay in vivo.

• Journal of the Korean Chemical Society
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• v.66 no.4
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• pp.298-304
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• 2022

The present study was designed to investigate the molecular mechanisms of DK-5-62, a novel (-)-catechin derivative on HCT116 human colorectal cancer cells. DK-5-62 inhibited the proliferation in dose- and time-dependent manner accompanied by the morphological changes. Effects of DK-5-62 appeared to be mediated by the induction of apoptosis, as manifested through DNA-binding dye Hoechst 33258 staining. Analysis of the mechanism of these events indicated that DK-5-62-treated cells exhibited an increased ratio of Bax/Bcl-2, resulting in the activation of caspase-9, caspase-3, and poly-ADP-ribose polymerase in a dose-dependent manner. Moreover, DK-5-62-induced apoptosis was accompanied by phosphorylation of the mitogen-activated protein kinase family, c-Jun N-terminal kinase, p38, and extracellular signal-regulated kinase. These results suggest that HCT116 cells are moderately sensitive to growth inhibition by DK-5-62 via apoptosis, as evidenced by activation of ERK/p38/Bcl-2 family signaling, as well as alteration in caspase-9 and caspase-3.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.39-44
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• 2001

Growth characters and productivities of corn varieties were compared to provide the basic data to the famers that in order to select the good corn varieties at Deakwanryoung district of Korea. Currently cultivated 8 recommended corn varieties and Suwon 19ho as check variety were used in this experiment and experimental design was randomized complete block with three replications. Resarch results obtained at Deakwanryoung branch (sea love 800m) of National Livestock Research Institute in 1999 are summarized as follows. Culm lengths of DK501 and GL4899 among corn varieties were shorter as 180cm and 198cm, respectively and rest of varieties were more or less 230cm and no difference among varieties. Inflorescence height was lower in varieties showing low culm length, and inflorescence heights of PK3525 and DK729 were higher about 10～15cm than those of other varieties. Stem diameters of all varieties except DK501 were thicker compared to check variety, Suwon 19ho and P3144W was thickest. Leaf numbers of late maturing DK729 and G4743 were higher as average 12 and 12.3 per plant, respectively. Silking dates among varieties were ranged from August 10 to 20 showing 10 day difference and DK501 was earliest as August 10 and G4743 was latest as August 20. Ear rates of early silking varieties were more than 46% and late silking varieties were less than 40%(P>0.1). Dry matter and TDN yield of P3351 was highest as 24,710 and 17,470kg/ha respectively, and DK729 and G4743 were second and third in order. In conclusion. early and medium maturing variety. P3352 with high yield and good growth characters was desirable at Deakwanryoung district of Korea.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.314-323
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• 2016

A transient ihpRNA-induced gene silencing system based on Agrobacterium-mediated injection infiltration has been established to evaluate candidate genes involved in proanthocyanidin (PAs) biosynthesis in persimmon (Diospyros kaki Thunb.). We chose DkPDS (phytoene desaturase) as a gene-silencing target to evaluate the newly developed transient gene silencing system. Our qRT-PCR analysis indicated that two ihpRNA constructs (pHG-PDS5' and pHG-PDS3') targeted DkPDS, which also led to significantly reduce expression of DkPDS in 'Mopanshi' persimmon leaves. To further confirm the reliability of the system, we successfully utilized it for DkLAR (leucoanthocyanidin reductase) gene silencing. The expression levels of DkLAR in 'Mopanshi' and 'Eshi 1' leaves were ca. 6-fold and ca. 5-fold lower than those in leaves harboring empty vector (pHG-GFP), respectively. DMACA (4-dimethylaminocinnamaldehyde) staining and the Folin-Ciocalteau assay showed that the accumulation of PAs was markedly inhibited in 'Mopanshi', 'Eshi 1' and 'Youhou' leaves. These results indicate that DkLAR plays an important role in the accumulation of PAs in persimmon. The transient ihpRNA-induced gene silencing method developed in this study is a highly efficient and useful tool for functional analysis of persimmon genes involved in PA biosynthesis.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.139-151
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• 2018

The Songgang-ri area, Cheongsong-gun, which is located in the Sobaeksan province of Yeongnam Massif near the southwestern boundary of Yeongyang subbasin of Gyeongsang Basin, consists of age unknown metamorphic rocks (banded gneiss, granitic gneiss, limesilicates) and age unknown igneous rock (granite gneiss) which intrudes them. This paper researched the geological structures of the Songgang-ri area from the geometric and kinematic features and the developing sequence of multi-deformed rock structures in the geological outcrops exposed about 170 m along the riverside of Yongjeoncheon in the eastern part of Songgang village, Songgang-ri. In the Songgang-ri geological outcrops are recognized three times (Fn, Fn+1, Fn+2) of folding, three times (Dk-I, Dk-II, Dk-III) intrusion of acidic dykes, one time of faulting, which are different in deformation and intrusion timing each other. These geological structures are at least formed by five times (Dn, Dn+1, Dn+2, Dn+3, Dn+4) of deformation. The Dn deformation is recognized by Fn fold which axial surface is parallel to the regional foliation. The Dn+1 intruded the (E)NE trending Dk-I dyke in the earlier phase and formed the NW trending Fn+1 fold in the later phase under compression of (E)NE-(W)SW direction. There are tight, isoclinal, intrafolial folds, boudinage, ${\sigma}$- or ${\delta}$-type boudins, asymmetric fold, C' shear band as the major deformed rock structures. The Dn+2 intruded the (N)NW trending Dk-II dyke in the earlier phase and formed NE trending Fn+2 fold in the later phase under compression of (N)NW-(S)SE direction. There are open fold and folded boudinage as those. The Dn+2 intruded the Dk-III dyke which cuts the Dk-I and Dk-II dykes and the axial surface of Fn+2 fold. The Dn+3 formed the left-handed reverse oblique-slip fault of NNE trend in which hanging wall moves into the SSE direction. Considering in that such five times of deformation recognized in the Songgang-ri geological outcrops are closely connected to the distribution and geological structure of the constituents in the more regional area as well as Songgang-ri area, the research result is expected to play a great data in clarifying and understanding the geological structure and its development process of the surrounding and boundary constituents of the Yeongnam Massif and Gyeongsang Basin.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.9-17
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• 2001

The purpose of this study is to perform the post occupancy evaluation in apartment housing with the dining room and kitchen(DK) facing the front side, and then to compare them with findings in unit plan facing the back side. A questionnaire survey method was used in this study. These questionnaires were administered, along with an interview, of 200 households in the apartment of 27-28 pyoung($76.50-78.54\textrm{m}^2$), in Gwangju city. Those living in an apartment with DK facing the front side tend to be less satisfied with the physical feature factors. expecially for layout of rooms, location of second bedroom and master bedroom, size and location of storage spaces, and location and size of balcony than those with the DK facing the back side.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.447-453
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• 1989

In order to study the transfer of antibiotics resistance genes of the genetically cloned bacteria in water environments, DK1 strain, which is resistant to kanamycin (Km), chloramphenicol (Cm), streptomycin (Sm), and sulfadiazine (Su), was selected from the Gram-negative bacterial isolates from wastewater. One of 4 plasmids harboured in the DK1 strain was found to possess Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ gene and be about 68 kb in size, and it was designated as pDK101. The plasmid of pDK101 was also found to have 16, 32, and 6 restriction sites for EcoRI. .PstI, and SalI, respectively. From the digestion fragments of pDK101 plasmid and pKT230 used as a vector by EcoRI restriction endonuclease, pDT309 and pDT529 were constructed as chimeric plasmids which possess Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ gene and are 30.9 and 52.9 kb in size, respectively. When the chimeric plasmids were trasformed into E. coli C600 or E. coli HB101, transformants of DKC601, DKC602, DKH102, and DKH103 were obtained as cloned bacterial cells. The Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ genes were well expressed in those cloned cells and the chimeric plasmids were clearly detected in the cloned cells of DKC601 and DKH103.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.117.3-118
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• 2003

We tested for the presence of double-stranded RNA (dsRNA) mycovirus in 827 Fusarium graminearum isolated from diseased barley and maize. dsRNA mycoviruses with various sizes were isolated. Of them, it was previously reported that dsRNA from DK2l isolate had pronounced morphological changes, including reduction in mycelial growth, increased to red pigmentation, reduced virulence and sporulation. (Chu et al., Appl. Environ. Microbiol. 2002). For better understanding of this hypovirulence associated with DK2l dsRNA virus, we determined the complete nucleotide sequence of dsRNA genome and named Fusarium hypovirus DK2l strain (Fhv-DK2l ). Genomic RNA of Fhv-DK2l was determined to be 6625 nucleotides in length excluding the poly (A) tail and contained three putative open reading frame. RNA-dependent RNA polymerase (RdRp) and helicase domain were expected in ORF A, 54 to 4709 nucleotide position. ORE B, 4752 to 5216 nucleotide position, and ORF C, 5475 to 6578 nucleotide position, were predicted to encode 16.7kDa and 41.3kDa protein respectively each. We could not detect any conserved domains from these two proteins. Phylogenetic analysis showed Fhv-DK2l was related to Cryphonectria hypovirus 3. Ten additional isolates were found that were infected with dsRNA mycoviruses. These mycoviruses contain 2 to 4 different segments of dsRNAs with the size range of approximately 1.7 to 10-kbp in length. The presence of dsRNAs isolates did not affect colony morphology and were transmissible through conidia and ascospore with incidence of 30-100％. These results indicate that there is genomic diversity of dsRNA mycoviruses that infect F. graminearum isolates and that impact of virus infection on host's morphology and virulence is determined by the interaction between dsRNAs and the fungal host, not by the mere presence of the dsRNAs

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.35-43
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• 2008

Purpose: This review article was written to investigate how the various factors, such as lacrimal thickness, CL's thickness and Dk, affects the influx of $O_2$ diffusion into the cornea. Methods: A mathematical model was proposed to analyze the oxygen diffusion reaching the cornea through the tear layers and contact lens based on Fick's law and the principle of continuity of the diffusion flux through the each layers. Results: The model predicts how the parameters such as the thickness of tear layer on the cornea, both the Dk and thickness of contact lenses etc., affect the oxygen tension at cornea and oxygen flux entering the cornea. Conclusions: It is found that either too flat or too tightly fitted contact lenses can cause the oxygen deficiency at/inside the periphery of the cornea because of the reduction of oxygen flux resulted from too thickened tear layer.