• Applied Microscopy
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• v.13 no.1
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• pp.63-70
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• 1983

The cell division of Bacillus thuringiensis are studed by a electron microscope. It was observed that when the cell division was occurred, the bacterial transverse septeum was centripetally formed, and the bacterial spore was divided into two daughter cells. The fore spore septum was initiated by invagination from either sides of the cell membranes, and was easily distinguished it from the transverse septum of the vegetative cell division. The large vesicular mesosome was. observed at one end of the cell membrane. The nucleoids were of variously irregular shapes and had no a nuclear membrane. The morphology of the bacteria was visualizd by a scanning electron microscope. The surface of the cell was generally rough and had a single polar flagellum, which was appeared to be $0.2{\mu}$ in width and $13{\mu}$ in length.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.144-144
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• 2012

최근 폴리머를 기판으로 하는 고속 Flexible TFT (Thin film transistor)나 고효율의 박막 태양전지(Thin film solar cell)를 실현시키기 위해 낮은 비저항(resistivity)을 가지며, 높은 홀 속도(carrier hall mobility)와 긴 이동거리를 가지는 다결정 반도체 박막(poly-crystalline semiconductor thin film)을 만들고자 하고 있다. 지금까지 다결정 박막 반도체를 만들기 위해서는 비교적 높은 온도에서 장시간의 열처리가 필요했으며, 이는 폴리머 기판의 문제점을 야기시킬 뿐 아니라 공정시간이 길다는 단점이 있었다. 이에 반도체 박막의 재결정화 온도를 낮추어 주는 metal (Al, Ni, Co, Cu, Ag, Pd, etc.)을 이용하여 결정화시키는 방법(MIC)이 많이 연구되어지고 있지만, 이 또한 재결정화가 이루어진 반도체 박막 안에 잔류 금속(residual metal)이 존재하게 되어 비저항을 높이고, 홀 속도와 이동거리를 감소시키는 단점이 있다. 이에 본 실험은, 종래의 MIC 결정화 방법에서 이용되어진 금속 증착막을 이용하는 대신, HIPIMS (High power impulse magnetron sputtering)와 PIII&D (Plasma immersion ion implantation and deposition) 공정을 복합시킨 방법으로 적은 양의 알루미늄을 이온주입함으로써 재결정화 온도를 낮추었을 뿐 아니라, 잔류하는 금속의 양도 매우 적은 다결정 반도체 박막을 만들 수 있었다. 분석 장비로는 박막의 결정화도를 측정하기 위해 GIXRD (Glazing incident x-ray diffraction analysis)와 Raman 분광분석법을 사용하였고, 잔류하는 금속의 양과 화학적 결합 상태를 알아보기 위해 XPS (X-ray photoelectron spectroscopy)를 통한 분석을 하였다. 또한, 표면 상태와 막의 성장 상태를 확인하기 위하여 HRTEM(High resolution transmission electron microscopy)를 통하여 관찰하였다.

• Animal cells and systems
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• v.10 no.3
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• pp.131-135
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• 2006

The ultrastructure of Aspergillus nidulans cell wall in relation to a mannoprotein was studied by scanning and transmission electron microscopy. An mnpAp null-mutant, DMPV1, was used as a negative control of a wild type VER7. To analyze whether the mannoprotein in the cell wall during the development of an mnpAp null-mutant is present or not, immunogold microscopy was also adopted. The surface sculpturing of various cell types - hyphae, conidium, Hulle cell, and ascospore - were not very different between the wild type and the mnpAp-null mutant (DMPV1) as examined by scanning electron microscopy. These results were comparable to those examined by transmission electron microscopy, in that the hyphal cell wall was not indentical between two strains, probably caused by the MnpA protein (MnpAp). MnpAp was absent in both the hyphal cell wall of the DMPV1 strain and the conidial cell wall of a wide type, but clearly recognized in the hyphal cell wall of a wild type.

• Food Science and Preservation
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• v.31 no.1
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• pp.99-111
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• 2024

The antioxidant potentials of ethanolic extracts derived from Aster yomena (A. yomena) were evaluated by assessing their total phenolic and flavonoid contents and radical scavenging activities. Our findings revealed that the 60% ethanolic extract of A. yomena exhibited the most robust antioxidant properties among all extracts tested. Specifically, the IC₅₀ values for the 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities of the 60% ethanolic extract from A. yomena were determined to be 1,640.30 ㎍/mL and 2,655.10 ㎍/mL, respectively. Moreover, the inhibitory effect on malondialdehyde increased with the 60% ethanolic extract from A. yomena. To assess the neuroprotective effects, we examined the impact of the 60% ethanolic extract from A. yomena against H₂O₂-induced cytotoxicity in HT-22 (mouse hippocampal neuronal cell line) and SK-N-MC (human neuroblastoma cell line) cells. The results demonstrated a significant improvement in cell viability and reduced intracellular oxidative stress. Furthermore, the major bioactive compounds present in the 60% ethanolic extract from A. yomena were identified as chlorogenic acid and rutin through high-performance liquid chromatography (HPLC) analysis.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.249-254
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• 2012

This study aimed at investigating whether a porcine follicular fluid (pFF) supplementation positively affects the characteristics of donor cells and the developmental competence of porcine cloned embryos. Ear fibroblast cells (donor cell) from an Massachusetts General Hospital miniature pig were cultured in different culture methods: (1) Dulbecco's modified Eagle's medium (DMEM)+10% FBS (Control); (2) DMEM+0.5% FBS (SS); and (3) DMEM+10% FBS+10% pFF (pFF) for 72 h. In each conditioned medium, the concentrations of 4 amino acids (Thr, Glu, Pro, and Val) in the pFF group were significantly different from those in the control group (p<0.05 or p<0.01). The proliferation of the cells cultured in the SS group was significantly lower than that of the other treatment groups (p<0.01). The population of apoptotic and necrotic cells in the SS group was significantly higher than that of either the control or the pFF group (p<0.01). The number of embryos that cleaved (p<0.05) and developed into blastocysts (p<0.01) in the SS group was significantly lower than that of either the control or the pFF group. Compared to other groups, the blastocysts produced from the donor cells in the pFF group had higher total cells and lower apoptotic cells (p<0.05). It can be concluded that pFF supplementation in the donor cell culture medium positively affects cell death, cell cycle and quality of the cloned blastocyst.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.227-229
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• 1999

Animal cell culture media are usually supplemented with fetal bovine serum (FBS); however, the use of FBS presents certain problems including high cost. By using an adaptation process and the addition of silkworm hemolymph, the FBS concentration can be reduced without causing a significant decrease in cell growth.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2738-2740
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• 2005

From composition transmitter is detached in indicator to individual load direction of 4 channels and adding up display by load cell indicator indication method of Bluetooth way is identifying marks.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.118-118
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• 2003

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.730-735
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• 1998

Power conditioning system, especially for power converter, is considered for the fuel cell power plants. Various characteristics of the fuel cell are analyzed and various choices of power converters are considered. One of the main converters, the boost type is selected and analyzed as an example.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.51-57
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• 2007

This study examined the possibility on the dietary value and cryopreservation of the marine microalga, Isochrysis galbana. Four cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), glycerol (Gly) and 1.2-propanedial (PD) were tested at the concentrations of 1.0, 1.5, 2.0, 2.5 and 3.0 M respectively. The highest survival rates were obtained with 1.5 and 2.0 M of four cryoprotectants yielding a survival rate of 80%. Cell concentration of $30\;{\times}\;10^4\;cell/ml$ at the initial point of the experiment was increased to $365\;{\times}\;10^4\;cell/ml$ in 1.5 M of dimethyl sulfoxide, $298\;{\times}\;10^4\;cell/ml$ in 1.5 M of ethylene glycol, $512\;{\times}\;10^4\;cell/ml$ in 1.5 M of glycerol, and $385\;{\times}\;10^4\;cell/ml$ in 1.5 M of 1.2-propanedial after five days, respectively. In dietary value experiment, survival rate and growth were not significantly different.