• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1435-1438
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• 1994

The effects of Ge composition variation in $a-Si_{1-x}Ge_x:H$ alloy p-i-n solar cells on the physical properties and current density-voltage characteristics are analyzed by a new simulation modelling based on the update published experimental datas. The simulation modelling includes newly formulated density of gap density spectrum corresponding to Ge composition variation and utilizes the newly derived generation rate formulars which include the reflection coefficients and can apply to multijunction structures as well as single junction structure. The effects in $a-Si_{1-x}Ge_x:H$ single junction are analyzed through the efficiency, fill factor, open circuit voltage, short circuit current density, free carriers, trap carriers, electric field, generation rate and recombination rate. Based on the results analyzed in single junction structure, the applications to multiple junction structures are discussed and the optimal conditions reaching to a high performance are investigated.

• IMMUNE NETWORK
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• v.20 no.4
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• pp.34.1-34.8
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• 2020

Cryopreservation and thawing of PBMCs are inevitable processes in expanding the scale of experiments in human immunology. Here, we carried out a fundamental study to investigate the detailed effects of PBMC cryopreservation and thawing on transcriptomes. We sorted Tregs from fresh and cryopreserved/thawed PBMCs from an identical donor and performed single-cell RNA-sequencing (scRNA-seq). We found that the cryopreservation and thawing process minimally affects the key molecular features of Tregs, including FOXP3. However, the cryopreserved and thawed sample had a specific cluster with up-regulation of genes for heat shock proteins. Caution may be warranted in interpreting the character of any cluster of cells with heat shock-related properties when cryopreserved and thawed samples are used for scRNA-seq.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.3
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• pp.310-316
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• 2014

Oldenlandia diffusa, Cremastra appendiculata and Fritillaria thunbergii are widely distributed in the Korea, China and Japan, and has been used in traditional medicine for various diseases, such as pharyngolaryngitis, tonsillitis, goiter and stomach ulcer. However, the anti-cancer activities in human breast cancer have not been clearly elucidated yet. In this study, it was compared the in vitro cytotoxic effects of single and complex treatment of O. diffusa, C. appendiculata and F. thunbergii. We treat human breast cancer MCF-7 cells with O. diffusa, C. appendiculata and F. thunbergii. And we evaluated viability, growth inhibition, morphological changes, apoptotic bodies formation, measurement of the cell cycle and formation of DNA fragmentation of these cells. It was found that single treatment of O. diffusa could inhibit the cell proliferation in human breast cancer MCF-7 cells. However, complex treatment of O. diffusa, C. appendiculata and F. thunbergii is weakly or not affect the cell proliferation of MCF-7 cells. And anti-proliferative effects of O. diffusa in MCF-7 cells was associated with G1 arrest of cell cycle. These findings suggest that O. diffusa may be a potential chemotherapeutic agent for the control of human breast cancer cells and further studies will be needed to identify the molecular mechanisms.

• The Journal of Korean Society for Radiation Therapy
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• v.4 no.1
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• pp.71-77
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• 1990

The present study was undertaken to investigate effects of ionizing radiation on DNA synthesis and chromosomal abnormality in cultured submandibular gland(SG) cells. SG cells from C57BL/6N Crj mice were cultured in Dulbecco's modified Eagle's medium (DME) supplemented with $10\%$ fetal bovine serum, antibiotics and fungizone. The cultured SG cells were irradiated with graded doses of gamma ray ($^{60}Co$) at a dose rate of 58.4rad/min. The effect of irradiation of $^{60}Co$ on DNA synthesis in cultured cells was evaluated by measuring the incorporation of 3H-TdR. Using conventional chromosome techniques and Giemsa staining methods, chromosomal abnormalities in cultured SG cells, induced by irradiation of $^{60}Co$ werw examined. Cytological observations were carried out by a light microscope with high resolving power. The results obtained were as follows : 1. DNA synthesis of SG cells was quantitatively dependent on a radiation dose compare to control. 2. A polyploids and few chromosome-type break, such as single and double breaks, deltions and triradial figures were more predominantly in irradiated SG cells than in control. This increase of chromosomal abnormality was in the proposition to the irradiation doses.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.569-570
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1007-1008
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• 2013

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.479-488
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• 2007

In spite of the attention given to the study of mesenchymal stem cells derived periodontal ligament (PDL), there is a lack of information about canine PDL cells. In this study, we characterized canine PDL cells to clarify their stem cell properties, including self renewal, proliferate rate, stem cell markers and multipotency. PDL cells were obtained from extracted premolars of canines, following a colony forming assay and proliferation rate of sub-confluent cultures of cells for self-renewal, immunostaining for STRO-1 and CD146/MUC18 and a differentiation assay for multipotency. Canine PDL cells formed single-cells colonies and 25% of the PDL cells displayed positive staining for BrdU. The cells expressed the mesenchymal stem-cell markers, STRO-1 and CD146/MUC18. Under defined culture conditions, the cells differentiated into osteoblasts and adipocytes, but the cells didn't differentiated into chondrocytes. The findings of this study indicated that the canine PDL cells possess crucial stem cells properties, such as self-renewal and multipotency, and express the mesenchymal stem cell markers on their surface. The isolation and characterization of canine PDL cells makes it feasible to pursue preclinical models of periodontal regeneration in canine.

• Toxicological Research
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• v.23 no.3
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• pp.253-261
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• 2007

In this study, we investigated the in vitro anti-obesity, anti-cancer activity and single oral dose toxicity of Inonotus xeranticus extracted by methanol (INXM) or ethyl acetate (INXE). In order to investigate anti-obestity effect of Inonotus xeranticus extracts, the 3T3-L1 cells were treated with these extracts at various concentrations(1, 10, 100 and $300{\mu}g/ml$). It was observed that 3T3-L1 cells treated with $100{\mu}g/ml$ of Inonotus obliquus ethyl acetate extract (INOE), INXM and INXE, in the absence of differentiation cocktail (0.5mM isobutylmethylxanthine (IBMX) $1{\mu}M$ dexamethasone, $1{\mu}M$ insulin), differentiated at a rate of 78.5, 80.9, and 76.4% respectively. Differentiation rates of 86.6% and 83.4% were observed in 3T3-L1 cells which were treated with differentiation cocktail at $100{\mu}g/ml$ of INXM and INXE, respectively. The anti-cancer effect of Inonotus xeranticus extracts was investigated using a method of sulforhodamine B in sarcoma 180 cell line. The cells were treated with these extracts (1, 10, 100 and $300{\mu}g/ml$) for 48 hours. The growth of cells which were treated with $300{\mu}g/ml$ of INXM was inhibited by 80.1%. The growth of sarcoma 180 cells which were treated with 100 and $300{\mu}g/ml$ of INXE was inhibited by 74.7% and 64.5%, respectively. In single oral dose toxicity study, no differences were observed between control and treated groups in clinical signs, body weight gains, and feed and water consumptions. The results indicated that Inonotus xeranticus extracts did not show any toxic effects at 2,000mg/kg in mice, and the $LD_{50}$ of these extracts was found to be higher than 2,000 mg/kg in this experiment. From the above results, Inonotus xeranticus methanol and ethyl acetate extracts might have useful clinical applications in the management of cancer and obesity and may also be useful as a medicinal food.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.204-205
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• 2011

In thin film silicon solar cells, p-i-n structure is adopted instead of p/n junction structure as in wafer-based Si solar cells. PECVD is a most widely used thin film deposition process for a-Si:H or ${\mu}c$-Si:H solar cells. For best performance of thin film silicon solar cell, the dopant profiles at p/i and i/n interfaces need to be as sharp as possible. The sharpness of dopant profiles can easily achieved when using multi-chamber PECVD equipment, in which each layer is deposited in separate chamber. However, in a single-chamber PECVD system, doped and intrinsic layers are deposited in one plasma chamber, which inevitably impedes sharp dopant profiles at the interfaces due to the contamination from previous deposition process. The cross-contamination between layers is a serious drawback of a single-chamber PECVD system in spite of the advantage of lower initial investment cost for the equipment. In order to resolve the cross-contamination problem in single-chamber PECVD systems, flushing method of the chamber with NH3 gas or water vapor after doped layer deposition process has been used. In this study, a new plasma process to solve the cross-contamination problem in a single-chamber PECVD system was suggested. A single-chamber VHF-PECVD system was used for superstrate type p-i-n a-Si:H solar cell manufacturing on Asahi-type U FTO glass. A 80 MHz and 20 watts of pulsed RF power was applied to the parallel plate RF cathode at the frequency of 10 kHz and 80% duty ratio. A mixture gas of Ar, H2 and SiH4 was used for i-layer deposition and the deposition pressure was 0.4 Torr. For p and n layer deposition, B2H6 and PH3 was used as doping gas, respectively. The deposition temperature was $250^{\circ}C$ and the total p-i-n layer thickness was about $3500{\AA}$. In order to remove the deposited B inside of the vacuum chamber during p-layer deposition, a high pulsed RF power of about 80 W was applied right after p-layer deposition without SiH4 gas, which is followed by i-layer and n-layer deposition. Finally, Ag was deposited as top electrode. The best initial solar cell efficiency of 9.5 % for test cell area of 0.2 $cm^2$ could be achieved by applying the in-situ plasma cleaning method. The dependence on RF power and treatment time was investigated along with the SIMS analysis of the p-i interface for boron profiles.

• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.63-72
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• 1998

-4-Quinolone antibiotics (pefloxacin, ciprofloxacin, norfoxacin, ofloxacin and enoxacin) were tested for mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA1538 and TA102, for chromosomal aberrations in cultured Chinese hamster lung (CHL) cells, and for wing somatic mutations and recombinations (wing spot) in Drosophila. Five 4-quinolones did not show any mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537 and TA1538. However, they were mutagenic inSalmonella typhimurium TA102 with and without metabolic activation in both plate incorporation method and preincubation method. Ciprofloxacin induced structural chromosome aberrations in CHL cells both with and without metabolic activation, and the frequencies were 6% and up to 28%, respectively. Pefloxacin showed equivocal evidence, however, norfloxacin, ofloxacin and enoxacin did not induce the structural chromosome aberrations both in the presence and absence of metabolic activation. In the wing spot assay in Drosophila, ofloxacin increased the frequency of small single spots significantly in a dose-dependent manner but there was no dose-dependent increase of single or twin spots in the others.