• Title/Summary/Keyword: micromorphology

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Changes of Surface Properties by Plasma Treatment on the Surface of Semiconductive Silicone Rubber (반도전성 실리콘 고무의 플라즈마 처리에 따른 표면의 특성변화)

  • Lee, Ki-Taek;Huh, Chang-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.8
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    • pp.696-701
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized (HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone rubber surface by oxygen plasma were accessed using Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), contact angle and Surface Roughness Tester. The results of the chemical analysis Showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx, x=$3\~4$) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized (HTV) semiconductive silicone rubber also, Surface roughness was increased with cleavage of side-chains and oxidation process, it confirmed change as the SEM. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

Helium Ion Microscopy of Uncoated Pine Leaves

  • Kim, Ki-Woo
    • Applied Microscopy
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    • v.42 no.3
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    • pp.147-150
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    • 2012
  • A recently introduced helium ion microscopy (HIM) was employed to observe uncoated pine leaf specimens. Adult leaves were collected from the seedlings of Pinus densiflora and P. rigida, air-dried at room temperature, and observed by HIM without metal coating. Ovoid or round stomata and distinct Florin rings could be discerned. The epicuticular waxes were present in the epistomatal chambers and Florin rings of stomata on the leaf surface. The epicuticular waxes were mostly straight, cylindrical, and ca. 1 ${\mu}m$ in length. The epistomatal chambers of P. rigida were filled with the epicuticular waxes, whereas those of P. densiflora were not filled with the epicuticular waxes. Based on their micromorphology, the epicuticular wax structures of the pine species were identified as tubules. These results suggest that the HIM could be used for the investigation of the plant stomata and epicuticular waxes of uncoated plant leaves. Due to the smaller ion probe and interaction volume, the HIM has advantages over conventional field emission scanning electron microscopy in terms of image resolution and charge neutralization.

Involvement of EBV-encoded BART-miRNAs and Dysregulated Cellular miRNAs in Nasopharyngeal Carcinoma Genesis

  • Xie, Yuan-Jie;Long, Zhi-Feng;He, Xiu-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5637-5644
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    • 2013
  • The definite molecular mechanisms underlying the genesis of nasopharyngeal carcinomas (NPCs) remain to be completely elucidated. miRNAs are small non-coding RNAs which are implicated in cell proliferation, apoptosis, and even carcinogenesis through negatively regulating gene expression post-transcriptionally. EBV was the first human virus found to express miRNAs. EBV-encoded BART-miRNAs and dysregulated cellular miRNAs are involved in carcinogenesis of NPC by interfering in the expression of viral and host cell genes related to immune responses and perturbing signal pathways of proliferation, apoptosis, invasion, metastasis and even radio-chemo-therapy sensitivity. Additional studies on the roles of EBV-encoded miRNAs and cellular miRNAs will provide new insights concerning the complicated gene regulated network and shed light on novel strategies for the diagnosis, therapy and prognosis of NPC.

Two New Records of Penicillium Associated with Blue Moldy Bulbs of Lily in Korea

  • Kim, Won-Ki;Park, Myung-Soo;Hahm, Soo-Sang;Yu, Seung-Hun
    • Mycobiology
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    • v.34 no.4
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    • pp.176-179
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    • 2006
  • Two new records of Penicillium from blue moldy bulbs of lily are reported in Korea. The Korean isolates of P. albocoremium (Frisvad) Frisvad and P. tulipae Overy and Frisvad were phylogenetically identical to the reference species based on DNA sequence of the ${\beta}-tubulin$ gene. P. albocoremium and P. tulipae are described and illustrated.

A Study of the Changes of Surface Properties on Semiconductive-Insulating of Silicone Rubber by Oxygen Plasma Treatment (산소 플라즈마 처리에 의한 반도전성 실리콘 고무 표면의 특성변화)

  • Lee, Ki-Taek;Hwang, Sun-Mook;Hong, Joo-Il;Huh, Chang-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.25-28
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized(HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone surface by oxygen plasma were accessed using x-ray photoelectron spectroscopy(XPS), contact angle and Scanning Electron Microscope(SEM). The results of the chemical analysis showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx. x=3~4) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized(HTV) semiconductive silicone rubber. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

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Morphological characteristics, distribution and taxonomic consideration of Chionanthus retusus Lindl. & Paxton in Korea (한국산 이팝나무(Chionanthus retusus Lindl. & Paxton)의 형태학적 특징, 분포 및 분류학적 검토)

  • Song, Jun-Ho;Kong, Min-Jung;Hong, Suk-Pyo
    • Korean Journal of Plant Taxonomy
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    • v.41 no.2
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    • pp.156-163
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    • 2011
  • The morphological characteristics of Chionanthus retusus Lindl. & Paxton in Korea are reviewed in this study through the comparison with its previous records and a distribution map of this species is created using previous flora and voucher specimens. The leaf epidermal micromorphology and the petiole anatomy are also briefly described.

Aphanoascus fulvescens: A New Record from Crop Field Soil in Korea

  • Gurung, Sun Kumar;Adhikari, Mahesh;Bazie, Setu;Kim, Hyun Seung;Lee, Hyun Gu;Lee, Hyang Burm;Lee, Youn Su
    • The Korean Journal of Mycology
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    • v.45 no.2
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    • pp.107-113
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    • 2017
  • Aphanoascus fulvescens KNU16-343 was isolated from crop field soil and identified based on morphological and molecular characteristics. The shape and size of conidia and conidiophores, as well as the internal transcribed spacer region of rDNA, confirmed that the isolate was A. fulvescens. This is the first report of this fungal species in Korea.

Phialocephala lagerbergii: A New Record from Crop Field Soil in Korea

  • Adhikari, Mahesh;Kim, Sangwoo;Yadav, Dil Raj;Um, Yong Hyun;Kim, Hyung Seung;Lee, Hyang Burm;Lee, Youn Su
    • The Korean Journal of Mycology
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    • v.44 no.3
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    • pp.132-137
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    • 2016
  • A unrecorded hyphomycete species of Phialocephala was isolated for the first time during the investigation of fungal community in the soil samples collected from different regions of Korea. The fungal isolate was identified as Phialocephala lagerbergii, based on the morphological characteristics and phylogenetic analysis of the ribosomal DNA sequence. In addition, cultural and micro-morphological features were described in detail.

Autofluorescence of artificial incipient root carious lesions

  • Lee, Hyeong-Mo;Park, Jeong-Kil;Hur, Bock
    • Proceedings of the KACD Conference
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    • 2003.11a
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    • pp.615-615
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    • 2003
  • I. Objectives This study was performed to get some information about micromorphology of subsurface lesion of root caries by observing autofluorescence using confocal laser scanning microscope(CLSM) with minimum sample preparation. II. Materials and Methods Half-cut and 1 mm thick sample of human teeth were prepared to produce artificial root carious lesions. Incipient subsurface lesions were produced under optimal pH and saturity. The lesions were observed by polarized microscopy, CLSM, and back-scattered electron microscope(BSE). Calcium and phosphorus concentrations of the lesions were analyzed by line EDAX. (omitted)

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A systematic study of Glechoma L. (Lamiaceae) based on micromorphological characters and nuclear ribosomal ITS sequences (미세구조학적 형질 및 핵 리보솜 DNA의 ITS 염기서열에 의한 긴병꽃풀속(꿀풀과)의 계통분류학적 연구)

  • Jang, Tae-Soo;Lee, Joongku;Hong, Suk-Pyo
    • Korean Journal of Plant Taxonomy
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    • v.44 no.1
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    • pp.22-32
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    • 2014
  • The petal and sepal micromorphology of five species of Glechoma (Lamiaceae) was investigated to evaluate their taxonomic significance, and a molecular phylogeny using the sequences of internal transcribed spacers (ITS) regions of nuclear ribosomal DNA was carried out to resolve their phylogenetic relationships. Stomatal complexes were mostly found in the inner and outer part of the sepal from all investigated taxa, and the size length of the guard cell was variable among the taxa. Five types of trichomes (uni-cellular non-glandular trichome, multi-cellular non-glandular trichome, short-stalked capitate glandular trichome, long-stalked capitate glandular trichome, and peltate glandular trichome) were variable among the taxa as well as their distribution and density. In molecular phylogenetic studies, the genus Glechoma was composed of three geographically distinct major monophyletic groups (Europe-U.S.A., China-Korea, Japan). G. longituba in Korea and China formed well-supported monophyletic group. G. hederacea in Europe and U.S.A. formed a monophyletic and well-supported clade with G. sardoa, which are endemic species in Italy, with G. hirsuta falling as a sister to this clade. However, G. grandis did not form any phylogenetic relationships with the remaining taxa. The ITS analyses provided taxonomic boundaries of taxa in Glechoma although the petal and sepal micromorphological characters provided weak evidences of the systematic value. As further studies, incorporating more DNA regions to the matrix including other additional morphological analysis will be significant to provide clearer taxonomic structure in Glechoma.