• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.616-622
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• 2001

Split-flow thin (SPLITT) cell Fractionation(SF) is a technique that allows separation of particulates and macromolecules into two fractions. A gravitational SF(GSF) system is constructed and tested for its applicability for separation of dust and ground water particulates. When tested with polystyrene latex particles, experimental data were in good agreements with theory. The 9.8 and 21.4㎛ polystyrene particles were successuflly separated in a continuous mode, where the mixture is continuously fed into the GSF channel allowing separation in a large sacle. The GSF system is successfully applied to continuous separation of dust and ground water particels based on the sedimentation coefficient, which is closely related to the particle size. The separations were confirmed by microscopy and energy-dispersive X-ray (EDX) analysos.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.19-26
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• 2001

Transformed Spodoptera frugiperda (Sf9) cells expressing baculovirus very late factor (VLF-1) were constructed by using Autograha nuclear polyhedrosis virus (AcNPV) immediate earthy gene (ie1). Neomycin-resistance gene as a selectable marker was introduced under the control of AcNPV ie1 promoter, and Bombyx mori nuclear polyhedrosis (BmNPV-K1) vlf-1 gene was introduced under the control of the Drosophila heat shock protein gene (hspr70) promoter to yield dual expression plasmid with two independent transcription units. It was transfected into Sf9 cells and cell clones expressing vlf-1 were selected by G4l8 treatment. Genomic DNA from transformed cells was isolated and integration of AcNPV iel harboring vlf-1 was confirmed by PCR using AcNPV iel-specific primers and Southern blot analysis. The transformed cells expressing VLF-1 in an infection-independent manner expressed foreign gene product of recombinant baculovirus in the earlier stage of infection compared with control Sf9 cells. These results suggest the possible to develop highly efficient transformed insect cells for baculovirus expression vector system.

• KSBB Journal
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• v.13 no.2
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• pp.181-186
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• 1998

In order to obtain high-level production of recombinant human thrombopoietin (rhTPO) in insect cell line, HTI-TN-5B1-4 (TN5), conditions for optimal rhTPO expression such as multiplicity of infection (MOI), the cell density at infection, harvesting time and type of culture method as well as growth media were determined. When TN5 cells were cultured as anchorage-dependent state in 60-mm dish, cell density $2\times^6$ cells,MOI of 10 and Garvesting the culture media at 72 hr post-infection wrere the cinditions for highest rh TPO production. High production of rhTPO was also achieved by using EXPRESS FIVE serum free media rather than SF900II serum free media-1. Anchorage-dependent TN5 cells were adapted as a suspension culture when they were grown in the presence of heparin. TN5 cells were successfully cultured at 0.2 L scale in suspension culture without having aggregation. When TN5 cells were cultured as suspension state, cell density of $0.6\times10^6$ cells/mL, MOI of 1 and harvesting the culture media at 72 hr post-infection, gave the highest yield of rhTPO.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.280-284
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• 2006

$\underline{Purpose}$: To evaluate biological characteristics of neutron beam generated by MC50 cyclotron located in the Korea Institute of Radiological and Medical Sciences (KIRAMS). $\underline{Materials\;and\;Methods}$: The neutron beams generated with 15 mm Beryllium target hit by 35 MeV proton beam was used and dosimetry data was measured before in-vitro study. We irradiated 0, 1, 2, 3, 4 and 5 Gy of neutron beam to EMT-6 cell line and surviving fraction (SF) was measured. The SF curve was also examined at the same dose when applying lead shielding to avoid gamma ray component. In the X-ray experiment, SF curve was obtained after irradiation of 0, 2, 5, 10, and 15 Gy. $\underline{Results}$: The neutron beams have 84% of neutron and 16% of gamma component at the depth of 2 cm with the field size of $26{\times}26\;cm^2$, beam current $20\;{\mu}A$, and dose rate of 9.25 cGy/min. The SF curve from X-ray, when fitted to linear-quadratic (LQ) model, had 0.611 as ${\alpha}/{\beta}$ ratio (${\alpha}=0.0204,\;{\beta}=0.0334,\;R^2=0.999$, respectively). The SF curve from neutron beam had shoulders at low dose area and fitted well to LQ model with the value of $R^2$ exceeding 0.99 in all experiments. The mean value of alpha and beta were -0.315 (range, $-0.254{\sim}-0.360$) and 0.247 ($0.220{\sim}0.262$), respectively. The addition of lead shielding resulted in no straightening of SF curve and shoulders in low dose area still existed. The RBE of neutron beam was in range of $2.07{\sim}2.19$ with SF=0.1 and $2.21{\sim}2.35$ with SF=0.01, respectively. $\underline{Conclusion}$: The neutron beam from MC50 cyclotron has significant amount of gamma component and this may have contributed to form the shoulder of survival curve. The RBE of neutron beam generated by MC50 was about 2.2.

• KSBB Journal
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• v.13 no.3
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• pp.231-237
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• 1998

An attenuated Japanese encephalitis virus (JEV) clone SA-14-14-2(Vero) was obtained through successive adaptation of a primary cell adapted strain, SA-14-14-2(PDK) to Vero cell, a continuous line of monkey kidney cells. The virus titer reached above the 107 plaque forming unit (pfu) per mL of culture supernatant with 3 passages in Vero cells and was maintained close to this level in the further passages. The optimum temperature for the virus growth was $35^{\circ}C$. Growth pattern of the virus indicated that optimum time for the virus harvest is 4 days post infection and the virus accomplished rapid initial propagation even in medium containing no serum supplement. The roller bottle (RB) system and the spinner flask (SF) system using micro-carrier (Cytodex-1) for the JEV cultivation were explored. When RB, SF, and T-flask culture system were compared, there was no significant difference in virus yield. Furthermore, the results indicated that virus could be harvested multiple times from 3 days to 9 days post infection; neither severe cytopathic effect (CPE) in the infected cells nor the decrease in the titer was observed on duration of 9 days.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1719-1727
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• 2014

In the present study, whispovirus immediate early 1 promoter (ie-1) was used to initiate surface expression of the hemagglutinin (HA) protein of Egyptian H5N1 avian influenza virus (AIV) by using the baculovirus expression vector system. The HA gene and whispovirus ie-1 promoter sequence were synthesized as a fused expression cassette (ie1-HA) and successfully cloned into the pFastBac-1 transfer vector. The recombinant vector was transformed into DH10Bac competent cells, and the recombinant bacmid was generated via site-specific transposition. The recombinant bacmid was used for transfection of Spodoptera frugiperda (Sf-9) insect cells to construct the recombinant baculovirus and to induce expression of the HA protein of H5N1 AIV. The recombinant glycoprotein expressed in Sf-9 cells showed hemadsorption activity. Hemagglutination activity was also detected in both extra- and intracellular recombinant HAs. Both the HA and hemadsorption activities were inhibited by reference polyclonal anti-H5 sera. Significant expression of the recombinant protein was observed on the surface of infected insect cells by using immunofluorescence. SDS-PAGE analysis of the expressed protein revealed the presence of a visually distinguishable band of ~63 kDa in size, which was absent in the non-infected cell control. Western blot analysis confirmed that the distinct 63 kDa band corresponded to the recombinant HA glycoprotein of H5N1 AIV. This study reports the successful expression of the HA protein of H5N1 AIV. The expressed protein was displayed on the plasma membrane of infected insect cells under the control of whispovirus ie-1 promoter by using the baculovirus expression vector system.

• Korean journal of applied entomology
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• v.55 no.3
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• pp.267-275
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• 2016

Chlorine dioxide has an insecticidal activity via its production of reactive oxygen species (ROS). Its cytotoxic activity has been regarded as a main cause of the insecticidal activity. This study tested a hypothesis that cytotoxicity of chlorine dioxide is resulted from its induction of apoptosis against target cells using ROS. Injection of chlorine dioxide significantly reduced total hemocyte counts of Plodia interpunctella larvae and subsequently killed the larvae. To analyze the cytotoxicity with respect to apoptosis, terminal deoxyribonucleotidyl transferase nick end translation (TUNEL) assay was performed. An insect cell line (Sf9) cells were exposed to different concentrations of chlorine dioxide. TUNEL assay showed that chlorine dioxide induced significant apoptosis of Sf9 cells in a dose-dependent manner. When different concentrations of chlorine dioxide were injected to larvae of P. interpunctella, it showed a dose-dependent induction of apoptosis against hemocytes. However, addition of vitamin E significantly suppressed the apoptosis induction and insecticidal activity of chlorine dioxide in a dose-dependent manner. These results suggest that cytotoxicity of chlorine dioxide is resulted from its induction of apoptosis against insect cells using ROS.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1158-1163
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• 1999

The purpose of this research is to measure nutrition counseling effects for improving iron status. The major components of the nutrition counseling were iron, MPF(Meat, Poultry, Fish) and vitamin C rich diet therapy, the provision of nutrient supplements and eatting attitude education. Fifteen female volun teers participated and the mean level for hemoglobin(Hgb), hematocrit(Hct), serum iron(S Fe), total iron binding capacity(TIBC), serum ferritin(SF) of subjects was 11.9±1.3g/dl, 37.0±2.7%, 57.7 ±33.9 g/dl, 409.1±56.2 g/dl, 8.6±3.5ng/ml, respectively. To evaluate the effect of iron status improvement by the nutrition couseling, 10 subjective symptoms, hematological indice and eating attitude were measured after implementation the nutrition counseling. Some subjective symptoms such as 'cold hands and foot', 'slow to recover', 'reduced concentrate', 'poor memory', 'inflammed inner mouth' were improved significantly. The hemoglobin, hematocrit, mean cell volume(MCV), mean cell hemoglobin(MCH) and mean cell hemo globin concentration(MCHC) were increased significantly. And eating attitude was improved significantly as well. It is suggested from the results that the nutrition counseling of this study can be effective to improve iron status.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.247-265
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• 1998

To determine the sequence and expression of the VP7 gene of Korean isolates (CAU-9), viral RNA was purified and used for cDNA amplification by RT-PCR. The VP7 cDNA was cloned, sequenced, and expressed using baculovirus expression system. The result showed that the sequence homologies CAU-9 compared with foreign isolated strains Wa, 417, TMC-II, 95B and SA11 were ranged from 74.0% to 95.1 % of nucleotide sequence and 35% to 43% of amino acid sequence, respectively. High homology of CAU-9 was observed in Japanease isolates 417 (nucleotide sequence homology was 95.1% and amino acid sequence homology was 43%). To express VP7 gene, the VP7 cDNA was cloned into pCR-Bac vector and inserted into the genome of baculovirus adjacent to the polyhedrin promoter by cotransfection of Spodoptera frugiperda (Sf9) insect cells with wild type baculovirus DNA. In antigenic analysis of Sf9 cells inoculated with the recombinant VP7, immunofluorescence assay revealed positive for viral antigens. In metabolic labeling of Sf9 cell lysates infected with recombinant baculoviruses, it was revealed that the protein of 34 kDa was expressed. The limited study of expressed VP7 protein inoculated with guinea pigs failed to elicit neutalizing antibody. As a results, the sequence analysis and expression of VP7 protein of rotavirus CAU-9 isolated from an infant in Korea could permit the conformation and development of virus like particles which may be useful in designing vaccine strategy.

• Journal of Nutrition and Health
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• v.32 no.8
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• pp.946-956
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• 1999

The iron nutritional status of 328(20-70 years old) women in Seoul and Puyo areas was evaluated using a dietary information and a measurement of hematological indices. The serum iron was measured by Red Blood Cell(RBC), Hemoglobin(Hb), Hematocrit(Hct), Serum Iron(S-Fe), Total Iron Binding Capacity (TIBC), Transferrin Saturation(TS) and Serum Ferritin(SF) and was analyzed with the information obtained by interviews which included socio-demographic variables and the dietary pattern of the subjects. The mean Hb was 12.6 $\pm$ 1.21g/dl(Seoul : 12.4 $\pm$ 1.14g/dl, Puyo : 13.2 $\pm$ 1.28g/dl), Hct was 38.7 $\pm$ 3.84%(Seoul: 37.5 $\pm$ 3.28%, Puyo: 4.19 $\pm$ 3.48%), S-Fe was 76.8 $\pm$ 31.49ug/dl(Seoul: 68.8 $\pm$ 27.3ug/dl, Puyo: 78.8 $\pm$ 32.3ug/dl) and TIBC was 277.7 $\pm$ 86.15ug/dl(Seoul: 354.1 $\pm$ 129.8ug/dl, Puyo: 259.0 $\pm$ 59.55ug/dl). The mean Ts(%) was 30.9 $\pm$ 17.9% (Seoul: 21.7 $\pm$ 10.52%, Puyo: 33.2 $\pm$ 18.68%) and the level was significantly higher in Puyo women(p<0.05). The mean SF was 45.4 $\pm$ 46.21ng/ml(Seoul: 53.6 $\pm$ 50.21ng/ml, Puyo: 36.1 $\pm$ 39.83ng/ml). The Red Blood Cell(RBC) showed a negative correlation with age and Hb, Hct showed a negative correlation with education and income level. However TIBC showed a and total energy expenditure per day. Energy, protein, carbohydrate, iron and vit.C intake showed a positive correlation with Hb and Hct. In particular, heme iron showed a positive correlation with RBC and nonheme iron of Hb, income level and iron intake affected on the level of Hct. In Seoul women, the age of menarche affected on the level of TIBC, total energy expenditure affected on the level of Hct. In Seoul women, the age of menarche affected on the level of TIBC, total energy expenditure affected on the level of S-Fe.