• 제목/요약/키워드: micromorphology

검색결과 56건 처리시간 0.025초

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

  • 이기택;허창수
    • 한국전기전자재료학회논문지
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    • 제18권8호
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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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    • 제42권3호
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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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    • 제14권10호
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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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    • 제34권4호
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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.

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

  • 이기택;황선묵;홍주일;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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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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한국산 이팝나무(Chionanthus retusus Lindl. & Paxton)의 형태학적 특징, 분포 및 분류학적 검토 (Morphological characteristics, distribution and taxonomic consideration of Chionanthus retusus Lindl. & Paxton in Korea)

  • 송준호;공민정;홍석표
    • 식물분류학회지
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    • 제41권2호
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    • pp.156-163
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    • 2011
  • 국내에 분포하는 이팝나무의 외부형태학적 형질을 재검토하여 기존 문헌과 선행 연구와의 차이를 파악하였으며, 식물상 문헌 및 표본정보를 통해 국내 분포도를 작성하였다. 또한 잎 표피 미세구조학적 형질과 엽병의 해부학적 형질을 추가하여 간략히 기재하였다.

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
    • 한국균학회지
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    • 제45권2호
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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
    • 한국균학회지
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    • 제44권3호
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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
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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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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미세구조학적 형질 및 핵 리보솜 DNA의 ITS 염기서열에 의한 긴병꽃풀속(꿀풀과)의 계통분류학적 연구 (A systematic study of Glechoma L. (Lamiaceae) based on micromorphological characters and nuclear ribosomal ITS sequences)

  • 장태수;이중구;홍석표
    • 식물분류학회지
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    • 제44권1호
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    • pp.22-32
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    • 2014
  • 꿀풀과에 속하는 긴병꽃풀속(Glechoma)내 5종에 대한 화판과 악편의 미세 구조를 관찰하여 기재하고 그 분류학적 유용성을 판단하였으며, 분자계통학적 유연관계를 확인하기 위하여 핵 리보솜 DNA의 ITS 염기서열에 기초한 연구를 수행하였다. 기공복합체는 조사된 모든 분류군의 악편에서 분포하였으며, 공변세포의 길이는 분류군마다 다소 차이를 보였다. 긴병꽃풀속 분류군들의 화판과 악에 분포하는 모용은 5 종류(단세포 비선모, 다세포 비선모, 짧은 자루 두상 선모, 긴 자루 두상 선모, 방패형 선모)로 나타났으며, 모용의 종류, 분포, 밀도가 분류군마다 다르게 나타났다. 핵 리보솜 DNA의 ITS 염기서열에 의한 분자계통학적 연구 결과 긴병꽃풀속은 분포지역에 따라 3개의 분계조(유럽-미국, 중국-한국, 일본)로 분리되었다. 한국과 중국에 분포하는 G. longituba는 단계통군을 이루었고, 이탈리아의 특산종인 G. sardoa와 미국 및 유럽에 분포하는 G. hederacea는 단계통군을 형성하였다. G. hirsuta는 유럽의 분계조와 자매군 관계를 이루었으나, 일본에 분포하는 G. grandis는 나머지 분류군들의 상호 유연관계에서 통계적 지지를 얻지 못하였다. 본 연구 결과에서 긴병꽃풀속내의 종간 한계 설정에 있어 화판 및 악의 미세형태형질의 연구보다 핵 리보솜 DNA의 ITS 염기서열에 기초한 분자 계통학적인 연구가 유용한 방법임이 판명되었다. 그러나 구체적인 본 속내 계통 분류학적인 논의를 위해서는 외부 형태학적 형질에 대한 분석을 동시에 수행할 필요가 있으며, 계통학적 유용성이 보다 높은 DNA 구간을 추가로 분석할 필요가 있다.