Recent advances in electron microscopy for the diagnosis and research of glomerular diseases

( Kazuho Honda ),( Takashi Takaki ),( Dedong Kang ) 대한신장학회 2023 Kidney Research and Clinical Practice Vol.42 No.2

Recent technical advances in the detection of backscattered electrons during scanning electron microscopy (SEM) have improved resolution and have provided several new technologies for research and clinical practice in kidney disease. The advances include three-dimensional (3D) electron microscopy (3D-EM), correlative light and electron microscopy (CLEM), low-vacuum SEM (LVSEM), and scanning transmission electron microscopy (STEM). 3D-EM analysis used to be laborious, but recently three different technologies, serial block-face SEM, focused ion beam SEM, and array tomography, have made 3D-EM easier by automating sectioning and the subsequent image acquisition in an SEM. CLEM is a method to correlate light microscopic images, especially immunofluorescent and electron microscopy images, providing detailed ultrastructure of the area of interest where the immunofluorescent marker is located. LVSEM enables the use of SEM on materials with poor electron conductivity. For example, LVSEM makes it possible for high resolution, 3D observation of paraffin sections. Finally, STEM is a method to observe ultrathin sections with improved resolution by using the focused electron beam scanning used in SEM and not the broad electron beam used in transmission electron microscopy. These technical advances in electron microscopy are promising to provide plenty of novel insights for understanding the pathogenesis and diagnosis of various glomerular diseases.

Studies on Thickness Swelling Mechanism of Wood Particle-Polypropylene Fiber Composite by Scanning Electron Microscopy

ChanHoLee,차재경,엄영근 한국목재공학회 2002 목재공학 Vol.30 No.3

This study was carried out through scanning electron microscopy to elucidate the mechanism of thickness swelling in wood particle-polypropylene composite which is a typical way of using wood and plastic materials. For this purpose, control particleboards and nonwoven web composites from wood particle and polypropylene fiber formulations of 100:0, 70:30, 60:40, and 50:50 were manufactured at target density levels of 0.5, 0.6, 0.7, and 0.8 g/cm3. Their water absorption and thickness swelling were tested according to ASTMD 1037-93 (1995). To elucidate thickness swelling mechanism of composite through the observation of morphological change of internal structures, the specimens before and after thickness swelling test by 24-hour immersion in water were used in scanning electron microscopy.From the scanning electron microscopy, thickness swelling of composite was thought to be caused by the complicated factors of degree of built-up internal stresses by mat compression and/or amount of wood particles encapsulated with molten polypropylene fibers during hot pressing. In the composites with wood particle contents of 50 to 60% at target densities of 0.5 to 0.8 g/cm3 and with wood particle content of 70% at target densities of 0.5 to 0.7 g/cm3, thickness swellings seemed to be largely dependent upon the restricted water uptake by encapsulated wood particles with molten polypropylene fibers. Thickness swelling in the composite with wood particle content of 70% at target density of 0.8 g/cm3, however, was thought to be principally dependent upon the increased springback phenomenon by built-up internal stresses of compressed mat.

주사 전자 현미경에서 전자빔 프르브 생성을 위한 하드웨어 설계

임선종,이찬홍 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Electron probe refers to the focused electron beam at the specimen. It generates the various image signals. Image of SEM is dependent upon the beam parameters: electron-probe size, electron-probe-current and electron probe convergence angle. In this paper, we presented hardware design for generation of electron probe.

전자현미경 개발

오현주(H. J. on),장동영(D. Y. Chang),양희남(H. N. Yang),김동환(D. H. Kim),박만진(M. J. Park),심치형(C. H. Shim),김충수(C. S. Kim) 한국생산제조학회 2005 한국생산제조시스템학회 학술발표대회 논문집 Vol.2005 No.5

We have designed and fabricated a thermal scanning electron microscopy. It includes an electron source, two condenser lenses, one objective lens, a scanning coil and a stigmator coil for focusing in column and also have a secondary electron detector for constructing the image in chamber with a high vacuum condition and control part for operating the SEM. Especially, in order for us to find out the optical characteristics, our attention and studies have been concentrated on the effects of two condenser lenses and one objective lens for high resolution with SEM. Finally, we developed a high resolution thermal scanning electron microscopy.

부직포식 복합재(Nonwoven Web Composites)의 접착성능에 관한 전자현미경적 연구

윤형운,엄영근,김현중 國民大學校 山林科學硏究所 1999 山林科學 Vol.11 No.-

This study was carried out to investigate the effects of process variable and coupling agent(MAPP) on the adhesion characteristics of nonwoven web composites through scanning electron microscopy. Under the process conditions of 195℃ and 30㎏f/㎠ in hot-pressing temperature and pressure. 50% wood fiber and 50% polypropylene fiber on the basis of oven-dried weight, and target density of 0.7 g/㎤, the proper hot-pressing time appeared 3 minutes or longer because the polypropylene fibers in the core of composites were incompletely melted under 3 minutes. There was no significant difference in the melting extent of polypropylene fibers in the range of hot-pressing temperatures from 190℃ to 200℃. This might be attributed to the large amount and high melt flow index(MFI) of polypropylene fibers. As the addition level of polypropylene fibers to wood fibers or the melt flow index of polypropylene fibers increased, the application of relatively lower hot-pressing temperature and easier adjustment of composite thickness might be feasible in manufacturing composites. The excessively high hot-platen temperature, however, might produce the composites with decreased thickness or thickness variation because of rapid melting and flow of polypropylene fibers and might involve the risk of thermal degradation of wood fibers. Scanning electron microscopy revealed no effect of cooling time, in the range of 2 to 4 minutes, on adhesion characteristics in the composite made with 50% polypropylene fiber and 50% wood fiber. This might be attributed to the decreased internal stress which caused by the lower density level of 0.7 g/㎤ and complete melting of polypropylene fibers which added in the large amount of 50% on the basis of oven-dried weight. In the composites made with 10% polypropylene fiber and 90% wood fiber, the addition of coupling agent appeared to render the wood fibers more flexible and the adhesion between wood and polypropylene fibers better but the increased addition of coupling agent from 1 to 3% exerted little influence upon the adhesion characteristics. The addition of coupling agent, on the other hand, proved to have no effect on adhesion characteristics in the composites made with 50% polypropylene fiber and 50% wood fiber.

전자현미경 개발

오현주,장동영,양희남,김동환,박만진,심치형,김충수 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

We have designed and fabricated a thermal scanning electron microscopy. It includes an electron source, two condenser lenses, one objective lens, a scanning coil and a stigmator coil for focusing in column and also have a secondary electron detector for constructing the image in chamber with a high vacuum condition and control part for operating the SEM. Especially, in order for us to find out the optical characteristics, our attention and studies have been concentrated on the effects of two condenser lenses and one objective lens for high resolution with SEM. Finally, we developed a high resolution thermal scanning electron microscopy.

전자현미경을 이용한 나노셀룰로오스 물질의 형태학적 특성 분석 연구

권오경(Ohkyung Kwon),신수정(Soo-Jeong Shin) 한국펄프·종이공학회 2016 펄프.종이기술 Vol.48 No.1

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.

Implant Surface Changes Observed with Confocal and Electron Microscopy After Probing with Metal and Plastic Periodontal Probes

진승호,박준범,손주완,고영경 대한구강악안면임플란트학회 2023 대한구강악안면임프란트학회지 Vol.27 No.4

Purpose: Probing around dental implants is recommended for the monitoring of peri-implant tissue health, but there are some risks associated with this procedure. There is a paucity of concrete evidence that contact with periodontal probes may leave remnants or indentations on the implant surface. The objective of this study was to provide visual evidence of the effects of probing around a rough-surface implant with metal and plastic periodontal probes, as assessed by confocal and scanning electron microscopy. Materials and Methods: Rough surface implants were placed in a pig mandible to simulate 8 mm of peri-implant bone loss. Probing around the entire circumference of the implants was performed using a metal and a plastic periodontal probe. Surface analysis was performed using confocal and scanning electron microscopy. Results: Confocal microscopy showed plastic remnants left on the thread peaks of the implant. Scanning electron microscopy showed smoothening of the sandblasted and acid-etched implant after probing. Conclusion: Contact with a periodontal probe leads to changes in the surface of rough-surface implants. The use of plastic probes may leave plastic remnants on the implant surface.

Characteristics of the Infection of Tilletia laevis Kühn (syn. Tilletia foetida (Wallr.) Liro.) in Compatible Wheat

Zhaoyu Ren,Wei Zhang,Mengke Wang,Haifeng Gao,Huimin Shen,Chunping Wang,Taiguo Liu,Wanquan Chen,Li Gao 한국식물병리학회 2021 Plant Pathology Journal Vol.37 No.5

Tilletia laevis Kühn (syn. Tilletia foetida (Wallr.) Liro.) causes wheat common bunt, which is one of the most devastating plant diseases in the world. Common bunt can result in a reduction of 80% or even a total loss of wheat production. In this study, the characteristics of T. laevis infection in compatible wheat plants were defined based on the combination of scanning electron mi- croscopy, transmission electron microscopy and laser scanning confocal microscopy. We found T. laevis could lead to the abnormal growth of wheat tissues and cells, such as leakage of chloroplasts, deformities, disordered arrangements of mesophyll cells and also thickening of the cell wall of mesophyll cells in leaf tissue. What’s more, T. laevis teliospores were found in the roots, stems, flag leaves, and glumes of infected wheat plants instead of just in the ovaries, as previously reported. The abnormal characteristics caused by T. laevis may be used for early detection of this pathogen instead of molecular markers in addition to providing theoretical insights into T. laevis and wheat interactions for breed- ing of common bunt resistance.

t-Butyl Alcohol 동결건조법을 이용한 흰쥐 간장의 주사전자현미경적 관찰

엄창섭,박은경,박창현,Uhm, Chang-Sub,Park, Eun-Kyung,Park, Chang-Hyun 한국현미경학회 1998 Applied microscopy Vol.28 No.3

T-butyl alcohol (TBA) freeze-drying method originally designed by Inoue and Osadake (1989) was adopted to dry specimens for scanning electron microscopy and the results were compared with those dried using critical point dryer (CPD). Small pieces $(1\times1\times3mm)$ of liver of Sprague-Dawley rats were cut and fixed in 2% glutaraldehyde in 0.1 M sodium cacodylate buffer after anesthesia, and processed for scanning electron microscopy by several modifications of TBA freeze-drying methods and by the standard preparation method using CPD. The bile canaliculi and sinusoidal endothelial surface were observed. Tissue dehydrated with TBA before TBA freeze-drying preserved the structures best comparable to those prepared with CPD. This result suggests that combination of dehydration with TBA and TBA freeze-drying is a superior method to the original TBA freeze-drying method dehydrated with ethanol.