• 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.

• 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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• 제46권2호
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• pp.71-75
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• 2016

The scanning electron microscope (SEM) offers two-dimensional (2D) micrographs of three-dimensional (3D) objects due to its inherent operating mechanisms. To overcome this limitation, other devices have been used for quantitative morphological analysis. Many efforts have been made on the applications of software-based approaches to 3D reconstruction and measurements by SEM. Based on the acquisition of two stereo images, a multi-view technique consists of two parts: (i) geometric calibration and (ii) image matching. Quantitative morphological parameters such as height and depth could be nondestructively measured by SEM combined with special software programs. It is also possible to obtain conventional surface parameters such as roughness and volume of biomedical specimens through 3D SEM surface reconstruction. There is growing evidence that conventional 2D SEM without special electron detectors can be transformed to 3D SEM for quantitative measurements in biomedical research.

• 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.

• 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.

• 복식
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• 제28권
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• pp.205-212
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• 1996

This paper is to study the characteristics of fabrics dyed with astringent unripe persimmon juice. The cotton silk rayon and nylon fabrics were dyed with astringet unripe persimmon juice. The structures of natural fabrics dyed fabrics and dyed fabrics followed by washing were examined by scanning electron mi-croscopy. Surface reflexibility of VIS trans-mittance of UV VIS and NIR were analyzed. The study conclues as follows: 1. Colour of cotton fabrics dyed with persim-mon juice became darkended as a function of exposing time to sunlight. That colour was chaged after washing. 2. Blocking effect of ultraciolet light and visible ray was increased in all dyed fabrics. Especially dyed cotton fabric blocked UV light perfectly and the blocking effect was still remained after 9 washings. 3. Persimmon juice dyeing produced coating effect to fabrics besides dyeing effect accord-ing to the scanning electron micrographs. In a word the cotton fabric dyed with per-simmon juice has blocking effect of UV light stiffness. Therefore I think persimmon juice dyeing is a very useful textile finishing and ex-pect a wide application of the technique in fu-ture.

• Mycobiology
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• 제28권1호
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• pp.47-50
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• 2000

The capability of higher ascomyceteous fungi to cause typical soft-rot decay for wood under laboratory conditions is reviewed and discussed. Fungi tested were extremely active in the decomposition of timbers. Scanning electron micrographs illustrated typical soft-rot decay pattern of higher wood decay ascomycetes, with the exception of H. trugodes that caused white-rot decay. Most of the fungi tested could be grouped as soft-rot fungi that showed typical soft-rot type II. Hypha confined primarily to the resin canals in softwoods or vessel elements in hardwoods and spread tracheid to tracheid via pits of cell wall to cell wall with mechanical force.

• Advanced Composite Materials
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• 제18권3호
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• pp.221-232
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• 2009

The allylamine plasma treatment is used to modify the surface properties of vapor grown carbon fibers (VGCF). It is to improve the interfacial bonding between the VGCF and epoxy matrix. The allylamine plasma process was performed by batch process in a vacuum chamber, using gas injection followed by plasma discharge for the durations of 20, 40 and 60 min. The interdependence of mechanical properties on the VGCF contents, treatment time and interfacial bonding between VGCF/ep was investigated. The interfacial bonding between VGCF and epoxy matrix was observed by scanning electron microscopy (SEM) micrographs of nanocomposites fracture surfaces. The changes in the mechanical properties of VGCF/ep, such as the tensile modulus and strength were discussed. The mechanical properties of allylamine plasma treated (AAPT) VGCF/ep were compared with those of raw VGCF/ep. The tensile strength and modulus of allyamine plasma treated VGCF40 (40 min treatment)/ep demonstrated a higher value than those of other samples. The mechanical properties were increased with the allyamine plasma treatment due to the improved adhesion at VGCF/ep interface. The modification of the carbon nanofibers surface was observed by transmission electron microscopy (TEM). SEM micrographs showed an excellent dispersion of VGCF in epoxy matrix by ultrasonic method.

• Parasites, Hosts and Diseases
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• 제58권4호
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• pp.403-411
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• 2020

Adult ascarid worms from the field mice, Apodemus agrarius, were observed with a light and scanning electron microscope, and molecularly analized with 18S rRNA gene. In the scanning electron microscope, 3 prominent labia were present in the anterior end of male and female worms, but the interlabia and gubernaculum were absent. Scanning electron micrographs showed cervical alae as vestigial organs that looked like a slightly uplifted superficial sewing stitch. Total 6 pairs of post-cloacal papillae were observed on the tail of the male worms. The tail of female worms was blunt and conical shape with a spine-like structure, mucron. The eggs were sub-globular, coated with the albuminous layer and 73 by 82 ㎛ in average size. The superficial pits of T. apodemi egg (mean 8.6×6.7 ㎛) are obviously bigger than those of Toxocara spp. The partial sequence of 18S rRNA showed the sequence homology of Toxocara canis (99.6%), Toxocara cati (99.4%), Toxascaris leonina (99.4%), and Toxocara vitulorum (99.2%). Conclusively, it was confirmed that ascarid nematodes, Toxocara apodemi, recovered from striped field mice in Korea are taxonomically conspecific relationship with genus Toxocara and genetic divergence from other Toxocara species.

• Parasites, Hosts and Diseases
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• 제21권1호
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• pp.75-82
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• 1983

An electron microscopic study was performed to know the basic tegumental structure of Cysticercus cellulosae. The scolex and bladder portions of cysticerci (human and porcine strains) were prepared for transmission and scanning electron microscopy by conventional procedures. In general, the tegument of C. cellulosae showed the basic ultrastructure of cestode tegument on electron micrographs. The teguments of both scolex and bladder portions consisted of such components, i.e., an outer vesicular layer with numerous microtriches and inner filroug layer. Below the fibrous layer, there were layers of muscle bundles and tegumental cells. The microtriches which covered the surface of cysticercus revealed two distinctly different shapes. The characteristic bladder-like, elongated pyramid shaped "tetrahedrial form" was observed on the surface of the scolex portion, whereas the elongated cylindrical "filamentous form" was distributed on the stirface of bladder portion. In spite of the difference of isolated host and location, the cysticerci showed tole same result. But dimensional variations of the tegument according to topography of the worm were observed. The possibility of application in making differential diagnosis from other larval cestodes and possible functions of this larval tegument were discussed.