• Journal of Microbiology
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• v.42 no.1
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• pp.25-31
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• 2004

Sf9 cells have obvious advantages for the conventional production technology of vaccine. They are useful tools for high concentration and large-scale cultures. Sf9 cells were grown to maximal concentration, 8${\times}$l0$\^$6/ cells/$m\ell$ in a 500$m\ell$ spinner flask, with a doubling time at the exponentially growing phase of 24.5 hours, using serum-free media. To explore the ability of Sf9 cells to be infected by the Japanese encephalitis (JE) virus Beijing-l strain, Sf9 cells were infected with the virus. By 4-5 days post-infection, 10-15 % of the Sf9 cells showed cytopathic effect (CPE), from granularity to the formation of syncytia and multinucleated giant cells continuously observed over a period of 35 days. Positive fluorescent reactions were detected in 30-40% of cells infected with the JE virus Beijing-l strain, and the uninfected Sf9 cells were completely negative. Virus particles, propagated in Sf9 and Vero cells, were concentrated by sedimentation on 40% trehalose cushions by ultracentrifugation, and showed identical patterns of viral morphogenesis. Complete virus particles, 40 to 50 nm in diameter, were observed, and JE virus envelope (E) proteins, at 53 kDa, were found in the western blot analysis to the anti-JE virus E protein monoclonal antibody and reacted as a magenta band in the same position to the glycoprotein staining. To evaluate whether the infectious virus was produced in Sf9 cells inoculated with the JE virus Beijing-l stain, Sf9 cells were inoculated with the virus, and sample harvested every 5 days. The titers of the JE virus Beijing-l strain rose from 1.0${\times}$l0$\^$5/ to 1.5${\times}$l0$\^$6/ pfu/$m\ell$. The infected Sf9 cells could be subcultured in serum-free medium, with no change in the plaque sizes formed by the JE virus Beijing-l strain in the plaque assay. It is suggested that the ability of the JE virus Beijing-l strain to infect Sf9 cells in serum-free media will provide a useful insect cell system, where the JE virus replication, cytopathogenicity and vaccine immunogen can be studied.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.405-415
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• 2000

Objective: The present study was undertaken to synthesize a human Y chromosome specific probe and to confirm the usefulness of the probe for fluorescence in situ hybridization (FISH) in various types of human cells. Methods: An approximately 400 bp DNA fragment of the DYZ1 sequences was synthesized by PCR using digoxigenin labeled dUTP (dig-PCR). The fidelity of probe was tested by FISH for cultured and uncultured human lymphocytes, amniocytes, chorionic villus cells, embryos, sperms, and germ cells of seminiferous tubule. Results: The human Y chromosome specific probe hybridized specifically to Y chromosome of the cells that had been tested. This probe assigned to the Yq12 region where the DYZ1 repetitive sequence is concentrated. Conclusion: We have identified a human Y chromosome specific probe that hybridized specifically to the Y chromosome by FISH for various types of uncultured as well as cultured cells. Therefore FISH technique using human Y chromosome specific probe should be useful for clinical application as a diagnostic tool for the detection of human Y chromosome.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.269-274
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• 2011

A solar cell is primary parts to produce electrical energy from the Sun. And, we can utilize those solar cells as a power generation system in home, factory, and so on. In order to make proper power, the solar cells are configured in series and parallel lay down. In condition of uniform illumination, the solar array will produce an enough power by photovoltaic effects from the solar cells. In case of non-uniform illumination on the solar cells, the power will be dramatically decreased compared to design. Fortunately, there were so many research outputs regarding the illumination effects on solar array. In this work, we tried to find out the non-uniform effects on unit CPV solar cell, because there were no research outputs for unit CPV solar cell considering illumination. The CPV solar cell was used in CPV system to make a power by the Sun. We chosen the triple junction solar cell of GaAsInP2Ge for simulation, which has a 30 % of conversion efficiency. By simulation, we obtained the output performance of CPV solar cells in condition of various illumination by using Hamming Window function. Its performance was degraded by 10 % to 50 % depending illumination conditions.

• Biomaterials Research
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• v.22 no.4
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• pp.271-278
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• 2018

Background: The chondrogenic differentiation of mesenchymal stem cells (MSCs) is regulated by many factors, including oxygen tensions, growth factors, and cytokines. Evidences have suggested that low oxygen tension seems to be an important regulatory factor in the proliferation and chondrogenic differentiation in various MSCs. Recent studies report that synovium-derived mesenchymal stem cells (SDSCs) are a potential source of stem cells for the repair of articular cartilage defects. But, the effect of low oxygen tension on the proliferation and chondrogenic differentiation in SDSCs has not characterized. In this study, we investigated the effects of hypoxia on proliferation and chondrogenesis in SDSCs. Method: SDSCs were isolated from patients with osteoarthritis at total knee replacement. To determine the effect of oxygen tension on proliferation and colony-forming characteristics of SDSCs, A colony-forming unit (CFU) assay and cell counting-based proliferation assay were performed under normoxic (21% oxygen) or hypoxic (5% oxygen). For in vitro chondrogenic differentiation, SDSCs were concentrated to form pellets and subjected to conditions appropriate for chondrogenic differentiation under normoxia and hypoxia, followed by the analysis for the expression of genes and proteins of chondrogenesis. qRT-PCR, histological assay, and glycosoaminoglycan assays were determined to assess chondrogenesis. Results: Low oxygen condition significantly increased proliferation and colony-forming characteristics of SDSCs compared to that of SDSCs under normoxic culture. Similar pellet size and weight were found for chondrogensis period under hypoxia and normoxia condition. The mRNA expression of types II collagen, aggrecan, and the transcription factor SOX9 was increased under hypoxia condition. Histological sections stained with Safranin-O demonstrated that hypoxic conditions had increased proteoglycan synthesis. Immunohistochemistry for types II collagen demonstrated that hypoxic culture of SDSCs increased type II collagen expression. In addition, GAG deposition was significantly higher in hypoxia compared with normoxia at 21 days of differentiation. Conclusion: These findings show that hypoxia condition has an important role in regulating the synthesis ECM matrix by SDSCs as they undergo chondrogenesis. This has important implications for cartilage tissue engineering applications of SDSCs.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.493-493
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• 2014

The manufacturing cost of thin-film photovoltics can potentially be lowered by minimizing the amount of a semiconductor material used to fabricate devices. Thin-film solar cells are typically only a few micrometers thick, whereas crystalline silicon (c-Si) wafer solar cells are $180{\sim}300\mu}m$ thick. As such, thin-film layers do not fully absorb incident light and their energy conversion efficiency is lower compared with that of c-Si wafer solar cells. Therefore, effective light trapping is required to realize commercially viable thin-film cells, particularly for indirect-band-gap semiconductors such as c-Si. An emerging method for light trapping in thin film solar cells is the use of metallic nanostructures that support surface plasmons. Plasmon-enhanced light absorption is shown to increase the cell photocurrent in many types of solar cells, specifically, in c-Si thin-film solar cells and in poly-Si thin film solar cell. By proper engineering of these structures, light can be concentrated and coupled into a thin semiconductor layer to increase light absorption. In many cases, silver (Ag) nanoparticles (NP) are formed either on the front surface or on the rear surface on the cells. In case of poly-Si thin film solar cells, Ag NPs are formed on the rear surface of the cells due to longer wavelengths are not perfectly absorbed in the active layer on the first path. In our cells, shorter wavelengths typically 300~500 nm are also not effectively absorbed. For this reason, a new concept of plasmonic nanostructure which is NPs formed both the front - and the rear - surface is worth testing. In this simulation Al NPs were located onto glass because Al has much lower parasitic absorption than other metal NPs. In case of Ag NP, it features parasitic absorption in the optical frequency range. On the other hand, Al NP, which is non-resonant metal NP, is characterized with a higher density of conduction electrons, resulting in highly negative dielectric permittivity. It makes them more suitable for the forward scattering configuration. In addition to this, Ag NP is located on the rear surface of the cell. Ag NPs showed good performance enhancement when they are located on the rear surface of our cells. In this simulation, Al NPs are located on glass and Ag NP is located on the rear Si surface. The structure for the simulation is shown in figure 1. Figure 2 shows FDTD-simulated absorption graphs of the proposed and reference structures. In the simulation, the front of the cell has Al NPs with 70 nm radius and 12.5% coverage; and the rear of the cell has Ag NPs with 157 nm in radius and 41.5% coverage. Such a structure shows better light absorption in 300~550 nm than that of the reference cell without any NPs and the structure with Ag NP on rear only. Therefore, it can be expected that enhanced light absorption of the structure with Al NP on front at 300~550 nm can contribute to the photocurrent enhancement.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.1
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• pp.37-42
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• 2013

The cells are concentrated approximately 20-fold by cytocentrifugation. This study evaluated the nucleated cell number for cells recovered on slide by using Cytospin-3 (Thermo Shandon Ltd. UK) and Cytopro-7620 (Wescor Inc., USA) cytocentrifuges to hematocytometer cell count of $0{\sim}5WBCs/{\mu}L$ of hematocytometer in the cerebrospinal fluid cell count. One hundred forty eight samples of $0{\sim}5WBCs/{\mu}L$ on hematocytometer, were cytocentrifuged by Cytospin-3 and Cytopro-7620 instruments. The nucleated cell number for cells recovered on slide was counted after Wright stain. The nucleated cell number for cells recovered on slide was 0~40 cells in the 44 samples of $0WBC/{\mu}L$, and 3~95 cells in the 31 samples of $1WBC/{\mu}L$. It was observed that the nucleated cell number for cells recovered on slide was 13~100 cells in the 44 samples of $2WBCs/{\mu}L$, and more than 100 cells in the 29 samples of $3{\sim}5WBCs/{\mu}L$, respectively. In addition, extremely normal lymphocyte, monocyte and polymorphonuclear neutrophil were observed in the 143 samples of $0{\sim}5WBCs/{\mu}L$. Macrophage and eosinophil were also rarely observed. The nucleated cell number for cells recovered on slide was 20 cells, which were regarded as $1WBC/{\mu}L$ in body fluid cell count. However, in this study, we made alterations to report nucleated cell percentage as 0% without preparing the cytocentrifuged slide at $0WBC/{\mu}L$ by using the cell yield in a comparison between the value of $0{\sim}5WBCs/{\mu}L$ and nucleated cell number for cells recovered on slide.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.654-658
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• 1999

To investigate an efficient microalgal feed for lariat culture of the Pacific oyster Crassostrea gigas, we prepared three types of Isochrysis aff, galbana (T-iso) : 1) freshly Harvested feed, 2) concentrated feed and 3) freeze-dried feed. The chemical compositions and fatty acid content of these feeds were evaluated and survival rate and lipid content of oyster larvae fed by these feeds were also determined. There was no significant difference in all types of feed in the gross biochemical compositions, In the fatty acid composition, the freeze-dried feed showed a significant increase in the level of polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than freshly Harvested feed, especially EPA was 7.35-fold higher than freshly Harvested feed. The survival rate of the oyster larvae was the highest when the larvae were fed with a diet of $10\%$ freeze-dried and $90\%$ concentrated feed; it was 2.1-fold higher than that fed with freshly Harvested food alone. Thereafter, the survival rate decreased with the increased substitutions of freeze-dried food, finally equalling that fed $100\%$ freshly harvested feed at the $30\%$ substitution. Larval lipid content of the oyster was also the highest when the larvae were fed with a diet of $10\%$ freeze-dried and $90\%$ concentrated feed. This increase was by 1.6-fold ver that fed $100\%$ freshly Harvested cells. Thus feed produced during slack times, on a seedling aquaculture farm, and preparedas a freeze-dried diet can be used, mixed with concentrated feed, to supply diets more efficiently and to improve the larvae survival rate of Pacific oyster.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.2 s.51
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• pp.207-212
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• 2005

Pomegranate (Punica granatum L.) which is very rich in Polyphenols and tannins was recently reported its anti-oxidant activities and phytoestrogenic activities in vivo test and many clinical studies, but the effects of them on the skin have not been reported. The experiments were tarried out in vitro to determine anti-oxidant activities of pomegranate extracts on DPPH radical scavenging assay, NBT/Xanthine Oxidase-superoxide scavenging assay, silica-induced intracellular $H_2O_2$, hydroperoxide and superoxide generation assay in RAW 264.7 cells. It showed that the methanolic extract of dried pomegranate peels have the most significant anti-oxidant activities on free radical scavenging assay and inhibitory activities on silica-induced intracellular free radical generation in RAW 264.7 cells. The concentrated juice of pomegranate showed only DPPH radical scavenging activities and inhibited hyaluronidase activity. Moreover, pomegranate seed oil inhibited specially silica-induced intracellular hydroperoxide generation in RAW 264.7 cells. These results suggest that the methanolic extract of dried pomegranate peels and pomegranate seed oil have more anti-oxidant activity than concentrated juice of pomegranate. Thus the extracts of pomegranate peels and seed oil could be developed cosmetic ingredients for anti-aging.

• Journal of Power Electronics
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• v.7 no.4
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• pp.343-352
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• 2007

This paper proposes a modularized charge equalization converter for hybrid electric vehicle (HEV) lithium-ion battery cells, in which the intra-module and the inter-module equalizer are Implemented. Considering the high voltage HEV battery pack, over approximately 300V, the proposed equalization circuit modularizes the entire $M^*N$ cells; in other words, M modules in the string and N cells in each module. With this modularization, low voltage stress on all the electronic devices, below roughly 64V, can be obtained. In the intra-module equalization, a current-fed DC/DC converter with cell selection switches is employed. By conducting these selection switches, concentrated charging of the specific under charged cells can be performed. On the other hand, the inter-module equalizer makes use of a voltage-fed DC/DC converter for bi-directional equalization. In the proposed circuit, these two converters can share the MOSFET switch so that low cost and small size can be achieved. In addition, the absence of any additional reset circuitry in the inter-module equalizer allows for further size reduction, concurrently conducting the multiple cell selection switches allows for shorter equalization time, and employing the optimal power rating design rule allows fur high power density to be obtained. Experimental results of an implemented prototype show that the proposed equalization scheme has the promised cell balancing performance for the 7Ah HEV lithium-ion battery string while maintaining low voltage stress, low cost, small size, and short equalization time.

• The Journal of Internal Korean Medicine
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• v.38 no.1
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• pp.1-9
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• 2017

Objective: This study investigated the effect of purified Carthamus tinctorius (C. tinctorius) extracted with a hot water and ethanol method on adipogenic differentiation of mouse bone marrow-derived mesenchymal stromal stem cells (mBMSCs). Methods: The C. tinctorius was extracted using hot water and ethanol. The samples were concentrated by a rotary evaporator and were then dried using a freeze-dryer. The mBMSCs were cultured and maintained in a minimum essential medium eagle alpha (${\alpha}-MEM$) supplemented with 10% FBS and 1% antibiotic antimycotic solution. To induce adipogenic differentiation, the cells were treated with Dulbecco's modified eagle's medium-low glucose (DMEM-LG) containing 1 mg/mL insulin, 1 mM dexamethasone, and 0.5 mM 3-isobutyl-1-methylxanthine. To evaluate the adipogenic differentiation ability, oil-red O staining was performed after adipogenic differentiation for 21 days. The mRNA expression and protein level of adipogenic-related genes were quantified by quantitative real-time PCR and western blotting, respectively. Results: In the results of the MTT assay, no concentrations of C. tinctorius extracts showed toxicity on mBMSCs, so we fixed the treatment concentration of the extract at 100 ng/mL. In oil-red O staining, the water-C. tinctorius extract treatment significantly decreased adipogenic differentiation compared with the control and ethanol extract groups. The water-C. tinctorius extract group in particular showed reduced mRNA and protein expression of Peroxisome proliferator-activated receptor gamma ($Ppar{\gamma}$) and CCAAT/enhancer-binding protein alpha ($C/ebp{\alpha}$), which are adipogenic-related transcription factors. Conclusion: These data suggest that extract of C. tinctorius decreased the adipogenic differentiation of mBMSCs, while only water-C. tinctorius extract had an effect on different adipogenesis in mBMSCs. The C. tinctorius will be a useful therapeutic reagent for the prevention of obesity-related diseases such as diabetes, hyperlipidemia, coronary artery disease, and osteoporosis.