• Elastomers and Composites
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• v.47 no.4
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• pp.310-317
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• 2012

A jute fiber surface was modified with argon gas in a cylinder type RF plasma generator to enhance the interfacial bond strength and to optimize the plasma treatment condition. The plasma power, gas pressure, and treat time were varied to figure out any effect of those parameters on the morphology and mechanical strength of jute fibers, and the interfacial bond strength for a model composite with polypropylene resin. As the severity of plasma treatment was increased, the surface of jute fibers became rougher. Gas pressure was less effective in roughening of the surface compared with those of treat time and plasma power. Approximately 25% drop in tensile strength of jute fibers was observed for the parameters of treat time and plasma power, while little deterioration was found for gas pressure, with increasing the severity. Based on the interfacial shear strength (IFSS), the optimum plasma treatment condition was determined to be treat time of 30 s, plasma power of 40 W, and gas pressure of 30 mTorr.

• YAKHAK HOEJI
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• v.47 no.2
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• pp.57-68
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• 2003

Under the active search for biologically active novel agents for cancer prevention and treatment, some agents have been found from plants which are easily available. Our previous research on them revealed that C. annuum L. var. angulosum Mill have high antiproliferating effect on cancer cells. However, it has not been known whether the anticancer efficacy is different according to each part of C. annuum L. var. angulosum Mill or whether it can be changed by timing of harvest or solvent for extraction. Thus we compared the efficacy of each part of C. annuum L. var. angulosum Mill and assessed how much difference in the efficacy can be made according to the time of harvest or solvents for extraction. We observed the morphologic change and apoptosis 48 hr after treatment with the extract of each part of C. annuum L. var. angulosum Mill in MCF-7 mammary gland adenocarcinoma cells and human hepatoma cells. We also counted cancer cells by trypan blue method and MTT method to check the cytotoxicity. The leaf extract showed the highest anticancer effect among all the parts of C. annuum L. var. angulosum Mill; 50％ and 70％ reduction in the number of cancer cells was observed at 25 $\mu\textrm{g}$/mι and 50 $\mu\textrm{g}$/mι, respectively. It was more than 2 times as potent as 5-fluorouracil (5-FU). We found chromosomal fragmentation, clumping, and destuction by PI staining, and DNA fragmentation by electrophoresis. In conclusion, this study suggests that leaf extraction using water as solvent has the highest antiproliferative and apoptotic activity in cancer cells compared with other parts of extraction.

• Korean Journal of Plant Taxonomy
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• v.48 no.3
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• pp.185-194
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• 2018

A comparative floral morphological study of 19 taxa in Persicaria sect. Cephalophilon with four taxa related to Koenigia was conducted to evaluate the taxonomic implications. The flowers of P. sect. Cephalophilon have (four-)five-lobed tepals; five, six, or eight stamens, and one pistil with two or three styles. The size range of each floral characteristic varies according to the taxa; generally P. humilis, P. glacialis var. glacialis and Koenigia taxa have rather small floral sizes. The connate degrees of the tepal lobes and styles also vary. The tepal epidermis consists of elongated rectangular cells with variation of the anticlinal cell walls (ACWs). Two types of glandular trichomes are found. The peltate glandular trichome (PT) was observed in nearly all of the studied taxa. The PT was consistently distributed on the outer tepal of P. sect. Cephalophilon, while Koenigia taxa and P. glacialis var. glacialis had this type of trichome on both sides of the tepal. P. criopolitana had only long-stalked pilate-glandular trichomes (LT) on the outer tepal. The nectary is distributed on the basal part of the inner tepal, with three possible shapes: dome-like, elongated, and disc-like nectary. The nectaries are always accompanied by elongated or spheroidal papillae. Various combinations of floral characters (e.g., the numbers of stamens and styles, the stigma shape, the nectary shape, ACWs, cuticular striation and the trichome type and distribution) of P. sect. Cephalophilon are useful when attempting to recognize the infrasectional levels of P. sect. Cephalophilon recently proposed. Here, we describe the floral characteristics in detail and discuss the taxonomic significance of the floral characters.

• Molecules and Cells
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• v.40 no.8
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• pp.550-557
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• 2017

The periodontal ligament (PDL) is the connective tissue between tooth root and alveolar bone containing mesenchymal stem cells (MSC). It has been suggested that human periodontal ligament stem cells (hPDLSCs) differentiate into osteo/cementoblast and ligament progenitor cells. The periodontitis is a representative oral disease where the PDL tissue is collapsed, and regeneration of this tissue is important in periodontitis therapy. Fibroblast growth factor-2 (FGF-2) stimulates proliferation and differentiation of fibroblastic MSCs into various cell lineages. We evaluated the dose efficacy of FGF-2 for cytodifferentiation of hPDLSCs into ligament progenitor. The fibrous morphology was highly stimulated even at low FGF-2 concentrations, and the expression of teno/ligamentogenic markers, scleraxis and tenomodulin in hPDLSCs increased in a dose dependent manner of FGF-2. In contrast, expression of the osteo/cementogenic markers decreased, suggesting that FGF-2 might induce and maintain the ligamentogenic potential of hPDLSCs. Although the stimulation of tenocytic maturation by $TGF-{\beta}1$ was diminished by FGF-2, the inhibition of the expression of early ligamentogenic marker by $TGF-{\beta}1$ was redeemed by FGF-2 treatment. The stimulating effect of BMPs on osteo/cementogenesis was apparently suppressed by FGF-2. These results indicate that FGF-2 predominantly differentiates the hPDLSCs into teno/ligamentogenesis, and has an antagonistic effect on the hard tissue differentiation induced by BMP-2 and BMP-4.

• Journal of Microbiology
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• v.45 no.3
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• pp.227-233
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• 2007

In budding yeast, septin plays as a scaffold to recruits protein components and regulates crucial cellular events including bud site selection, bud morphogenesis, Cdc28 activation pathway, and cytokinesis. Phosphorylation of Bni5 isolated as a suppressor for septin defect is essential to Swe1-dependent regulation of bud morphogenesis and mitotic entry. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we provide evidence that Bni5 phosphorylation is important for interaction with septin component Cdc11 and for timely delocalization from septin filament at late mitosis. Phosphorylation-deficient bni5-4A was synthetically lethal with $hof1{\Delta}$. bni5-4A cells had defective structure of septin ring and connected cell morphology, indicative of defects in cytokinesis. Two-hybrid analysis revealed that bni5-4A has a defect in direct interaction with Cdc11 and Cdc12. GFP-tagged bni5-4A was normally localized at mother-bud neck of budded cells before middle of mitosis. In contrast, at large-budded telophase cells, bni5-4A-GFP was defective in localization and disappeared from the neck approximately 2 min earlier than that of wild type, as evidenced by time-lapse analysis. Therefore, earlier delocalization of bni5-4A from septin filament is consistent with phosphorylation-dependent interaction with the septin component. These results suggest that timely de localization of Bni5 by phosphorylation is important for septin function and regulation of cytokinesis.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.605-611
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• 2014

$SrGd_{2-x}(MoO_4)_4:Er^{3+}/Yb^3$ phosphors with doping concentrations of $Er^{3+}$+ and $Yb^{3+}$ ($x=Er^{3+}+Yb^{3+}$, $Er^{3+}=0.05$, 0.1, 0.2, and $Yb^{3+}=0.2$, 0.45) were successfully synthesized by the cyclic microwave-modified sol-gel method, and their upconversion mechanism and spectroscopic properties have been investigated in detail. Well-crystallized particles showed a fine and homogeneous morphology with grain sizes of $2-5{\mu}m$. Under excitation at 980 nm, $SrGd_{1.7}(MoO_4)_4:Er_{0.1}Yb_{0.2}$ and $SrGd_{1.5}(MoO_4)_4:Er_{0.05}Yb_{0.45}$ particles exhibited a strong 525-nm emission band, a weak 550-nm emission band in the green region, and a very weak 655-nm emission band in the red region. The Raman spectra of the doped particles indicated the domination of strong peaks at higher frequencies of 1023, 1092, and $1325cm^{-1}$ and at lower frequencies of 223, 2932, 365, 428, 538, and $594cm^{-1}$ induced by the incorporation of the $Er^{3+}$+ and $Yb^{3+}$+ elements into the $Gd^{3+}$ site in the crystal lattice, which resulted in the unit cell shrinkage accompanying a new phase formation of the $[MoO_4]^{2-}$ groups.

• Applied Microscopy
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• v.46 no.4
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• pp.193-200
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• 2016

Male reproductive organs are strongly affected by estrogen signaling mediated via the estrogen receptor. In this study, propyl pyrazole triol (PPT), an estrogen receptor alpha agonist, was subcutaneously injected in adult male mice every 2 days for a total duration of 8, 16, or 24 days. Histological changes in the reproductive organs, including the testes, efferent ductules, and epididymides, were observed. The weight of the reproductive organs decreased in the PPT group. In addition, the diameter of the seminiferous tubules decreased in the PPT group compared with the control group. The epithelial cell height decreased in the initial segment of the epididymis, whereas the luminal diameter increased in the efferent ductules of the PPT group. PPT induced irregular morphology of stereocilia in the luminal region of the initial segment. Therefore, PPT treatment at high concentrations had inhibitory effects in the reproductive organs of adult male mice. These findings suggest that short-term treatment with estrogen receptor agonist causes histological changes in the testes, efferent ductules, and epididymis, which are similar to those caused by estrogen receptor antagonist treatment. Therefore, the estrogen receptor may have functional roles in male reproductive organs, implying that treatment with an estrogen receptor agonist can affect male fertility.

• Journal of Embryo Transfer
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• v.29 no.4
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• pp.351-359
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• 2014

Phasianus colchicus is not only a beautiful bird but also a great value in science and under the threat of endanger. Hence, the aim of this study was to isolate the pheasant male germ cells (mGCs) and then induce them into elongated sperm-like cells in vitro. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the c-kit positive cells and c-kit negative cells examined by flow cytometry analysis (FCA) was 92.87% and 2.57%, respectively. Subsequently, the mGCs were induced for 48h in DMEM/F12 medium supplemented factors such as retinol acid, testosterone and bovine FSH, followed by 5 weeks in culture. We found that some elongated sperm-like cells appeared initially in vitro under inducement of stimulated factors. The elongated sperm-like cells showed in the expression of changed morphology and post-transcriptional marker such as spermatid associated (SPERT), spermatid perinuclear RNA binding protein (STRBP), round spermatid basic protein 1 (RSBN1) and SPER1L. Moreover, in DNA content identified assay, induced cells showed that the 1C DNA population markedly increased in differentiated group but it was not change in undifferentiated group. Successful in vitro differentiation of pheasant testicular germline cells into spermatids appears to offer extremely attractive potential for the conservation of endangered birds and treatment of male infertility.

• Journal of Species Research
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• v.7 no.3
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• pp.231-239
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• 2018

While screening indigenous prokaryotic species in Republic of Korea in 2017, a total of 17 bacterial strains assigned to the phylum Bacteroidetes were isolated from a variety of environmental habitats including water of fountain, tidal flat, plant root, soil, the gut of Russian grayling butterfly, ginseng field, seawater, lagoon and seashore sand. From the 16S rRNA gene sequence similarity of more than 98.7% and the formation of a robust phylogenetic clade with the closest species, it was found that the 17 strains belong to independent and recognized bacterial species. There has been no official report that the identified 17 species have been previously isolated in the Republic of Korea. Thus, 15 species in 10 genera of one family in the order Flavobacteriales, one species in one genus of one family in the order Cytophagales, and one species in one genus of one family in the order Sphingobacteriales are proposed as unrecorded species of the phylum Bacteroidetes found in the Republic of Korea. Gram reaction, colony and cell morphology, basic phenotypic characteristics, isolation source, taxonomic status, strain ID and other information are described in the species descriptions.

• Journal of Species Research
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• v.9 no.2
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• pp.85-104
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• 2020

In 2019, after a comprehensive investigation of indigenous prokaryotic species in Korea, a total of 12 bacterial strains assigned to the phylum Proteobacteria were isolated from soil. With the high 16S rRNA gene sequence similarity (>98.8%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to independent, predefined bacterial species. This study identified two species in the family Burkholderiaceae, one species in the family Comamonadaceae, two species in the family Oxalobacteraceae, one species in the family Micrococcaceae, one species in the family Bradyrhizobiaceae, one species in the family Methylobacteriaceae, one species in the family Rhizobiaceae, one species in the family Rhodocyclaceae, and one species in the family Sphingomonadaceae. There is no official report about these 12 species in Korea, so are described as unreported bacterial species in Korea in this study. Gram reaction, basic biochemical characteristics, colony, and cell morphology are also described in the species description section.