• 대한의생명과학회지
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• 제6권2호
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• pp.109-118
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• 2000

본 연구는 전자현미경적인 방법을 이용하여 흰쥐 기관지와 폐조직에 미치는 간접흡연의 영향을 조사하였다. 실험동물은 1일 3회씩 매회 15분간, 4주 동안 비주류 담배연기를 흡입하도록 하였다. 간접흡연 그룹의 폐조직에서는 세포질내에 다수의 용해소체을 함유하고 있는 중성구, 그리고 다양한 크기의 용해소체와 잔사체를 함유하는 대식 세포가 관찰되었다. 또한 폐포격벽은 팽대되었으며 섬유화현상이 나타났다. 기관지상피는 섬모상피세포가 점차 소실되었고, 분비세포 또는 배상세포들은 그 수가 증가하였으며, 섬모가 소실되고 표면적이 확장된 배상세포도 관찰되었다. 본 연구결과 이러한 미세구조의 변화는 간접흡연에 의한 세포상해의 전형적인 결과로 파악된다.

• Animal Systematics, Evolution and Diversity
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• 제36권2호
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• pp.113-122
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• 2020

From a moss sample, we isolated and identified Notohymena gangwonensis Kim et al., 2019 based on morphological and molecular data. The moss and type population has completely identical 18S rRNA (nuclear small subunit ribosomal RNA) gene sequences and both are highly similar in morphological and morphometric attributes, except for the diameter and arrangement of the cortical granules. Thus, we reexamined the type materials(i.e., micrographs and gDNA) and resulted in finding mistakes made by the authors of the species. Based on these data and supporting materials newly obtained (i.e., internal transcribed spacer [ITS] 1, ITS2, 5.8S, and partial 28S rDNA sequences, and scanning electron micrographs), we provide improved diagnosis of the species to clarify its identity. In addition, a key for Notohymena species is provided.

• Journal of Ginseng Research
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• 제13권1호
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• pp.49-55
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• 1989

정상 wistar rat strain의 체중 및 장기무게 변화 그리고 사료, 물 섭취량의 변화 등을 조사함으로써 polyacetylene 화합물들의 투여량에 따른 독성변수(toxicological parameter)의 범위를 추정하고자 하였다. 또한, ICR mouse strain의 Sarcoma-180으로 유도되는 고형암의 억제와 관련해서 polyacetylene 화합물들의 투여량에 따른 독성변수(toxicological parameter)와의 관계를 관찰하고자 하였다. Panaxydol 40$\mumoles/kg b.w.을 3일간 연속 복강 투여했을때 wistar rat의 체중증가율은 대조군보다 약 17% 감소하였으나, polyacetylene 의 투여를 중지하면 약 4일 경과후부터 체중증가율이 정상으로 회복되었다. 이 투여량을 20$\mumoles/kg b.w.로 줄이면 대조군과의 체중증가율의 차이는 약 10% 정도로 완화되며 그 체중감소율은 panaxydol, panaxynol, panaxytriol의 순으로 증가하였다. 이때 장기무게의 관찰 결과는 대조군과 polyacetylene 화합물들 투여군 사이에 의미있는 차이가 없는 것으로 나타났다. 또한 정상 mice의 간세포에 대한 electron micrograph 관찰결과, panaxydol 40$\mumoles/kg b.w./day 투여시에도 대조군에 비하여 별다른 미세조직의 변화가 관찰되지 않았다.

• 한국염색가공학회지
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• 제1권1호
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• pp.35-46
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• 1989

Experiments described in which cotton fabrics at different stages of chemical processing were abraded to different extents on a Stoll Abrasion Tester with three different abradants, namely, a worsted fabric, flax fabric and silicon carbide paper. The four different plain-weave cotton fabrics selected were 1) desized, 2) scoured and bleached, 3) mercerized, 4) resin-treated. The surface abrasive damages of treated fabrics were observed by SAM, and load-elongation percent retentions of abraded samples were measured by Instrong Tester. The result were as follows: 1. The maximum percent retention of load-elongation with three different abradants was exhibited by the scoured and bleached fabrics and the minimum by the resin finished fabric. 2. The electron micrographs of four different cotton fabrics abraded by flax, worsted fabric abradants for 900 rubs showed a large number of criss-crossing stray fibers in fabric structure. It may be the molecular adhesion for frictional resistance to be explained. 3. The electron micrographs of four different cotton fabrics abraded by silicone carbide abradants showed the form of busing or mashing fibers in fabric structure. The above might be on the basis of the ploughing theory.

• 대한세포병리학회지
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• 제7권1호
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• pp.23-30
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• 1996

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs, nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma, the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ in their chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.

• Applied Microscopy
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• 제45권3호
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• pp.150-154
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• 2015

Negative staining electron microscopy facilitates the visualization of small bio-materials such as proteins; thus, many electron microscopists have used this conventional method to visualize the morphologies and structures of biological materials. To achieve sufficient contrast of the materials, a number of imaging parameters must be considered. Here, we examined the effects of one of the fundamental imaging parameters, electron beam exposure time, on electron densities generated using transmission electron microscopy. A single site of a negatively stained biological sample was illuminated with the electron beam for different times (1, 2, or 4 seconds) and sets of micrographs were collected. Computational image processing demonstrated that longer exposure times provide better electron densities at the molecular level. This report describes technical procedures for testing parameters that allow enhanced evaluations of the densities of electron microscopy images.

• 펄프종이기술
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• 제48권1호
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• pp.5-18
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• 2016

Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.

• Applied Microscopy
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• 제1권1호
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• pp.3-10
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• 1969

By the use of electron microscope, the study has beek made on the grain size in photo graphic emulsions, which are made at different temperature. It is found that ,the optimum temperature is $60^{\circ}C$, at which the average grain size obtained is the biggest. Also electron micrographs show NaCl-type crystal structure of AgBr and AgCl, as we expected.

• Applied Microscopy
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• 제48권4호
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• pp.132-133
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• 2018

One of the most important factors determining the properties of a material is its grain size. However, unclear grain boundaries in the image hinder an accurate measurement of grain size. We demonstrate that grain boundaries existing in the images obtained by scanning transmission electron microscopy (STEM) can be clearly distinguished by applying a Sobel filter to a tilting series of STEM images of a hydrogenation-disproportionation-desorption-recombination processed Nd2Fe14B magnet sample.

• Applied Microscopy
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• 제35권1호
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• pp.1-13
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• 2005

전자현미경 관찰에 있어서 최종적인 목표는 정확한 정보를 포함하는 좋은 사진을 얻는 것이라 할 수 있다. 이를 위하여는 사진에 인공물이 포함되지 않도록 표본의 채취, 처리, 관찰 및 사진 작업 등 모든 단계에서 주의를 기울여야 한다. 본 고에서는 통상적인 전자현미경 관찰을 위한 시료의 채취로부터 사진의 현상, 인화에 이르는 여러 단계에서 발생될 수 있는 인공물들과 그 원인을 살펴 보고 해결책을 제시함으로써 전자현미경 관찰을 위한 표본의 올바른 제작과 미세구조의 해석에 도움을 주고자 하였다.