• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.8-13
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• 2018

Nitrogen oxides (NOx) have recently been very influential in the generation of ultrafine dust, which is of great social interest in terms of improving the atmospheric environment. Nitrogen oxides are generated mainly by the reaction of nitrogen and oxygen in air in a combustion gas atmosphere of high temperature in a combustion apparatus such as thermal power generation. Recently, research has been conducted on the combustion that recirculates the exhaust gas to the cylindrical burner by using a piping using a Coanda nozzle. In this study, three types of burners were carried out through computational fluid analysis. Case 1 burner with the outlet of the combustion gas to the right, Case 2 burner with both sides as gas exit, Case 3 burner with left side gas exit. The pressure, flow, temperature, combustion reaction rate and distribution characteristics of nitrogen oxides were compared and analyzed. The combustion reaction occurred in Case 1 and Case 2 burner in the right direction with combustion gas recirculation inlet and Case 3 burner in the vicinity of mixed gas inlet. The temperature at the outlet was about $100^{\circ}C$ lower than that of the other burners as the Case 2 burner was exhausted to both sides. The NOx concentration of Case 1 burner at the exit was about 20 times larger than that of the other burners. From the present study, it could be seen that it is effective for the NOx reduction to exhaust the exhaust gas to both side gas exits or to exhaust the exhaust gas to the opposite direction of inlet of recirculation gas.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.11-16
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• 2012

Cancer stem cells (CSCs) are often characterized by the elevated expression of drug-resistance related stem-cell surface markers, such as CD133 and ABCG2. Recently, we reported that CSCs have a high level of expression of the IL-6 receptor (IL-6R). The purpose of this study was to investigate the effect of anticancer drugs on the expression of the drug resistance-related cancer stem cell markers, ABCG2, IL-6R, and CD133 in non-small cell lung cancer (NSCLC) cell lines. A549, H460, and H23 NSCLC cell lines were treated with the anticancer drugs 5-fluorouracil (5-FU; $25{\mu}g/ml$) and methotrexate (MTX; $50{\mu}g/ml$), and the expression of putative CSC markers was analyzed by fluorescent activated cell sorter (FACS) and the gene expression level of abcg2, il-6r and cd133 by reverse transcriptase-polymerase chain reaction (RT-PCR). We found that the fraction of ABCG2-positive(+) cells was significantly increased by treatment with both 5-FU and MTX in NSCLC cells, and the elevation of abcg2, il-6r and cd133 expressions in response to these drugs was also confirmed using RT-PCR. Also, the number of IL-6R(+) cells was increased by MTX in the 3 cell lines mentioned and increased by 5-FU in the H460 cell line. The number of CD133(+) cells was also significantly increased by both 5-FU and MTX treatment in all of the cell lines tested. These results indicate that 5-FU and MTX considerably enhance the expression of drug-resistance related CSC markers in NSCLC cell lines. Thus, we suggest that antimetabolite cancer drugs, such as 5-FU and MTX, can lead to the propagation of CSCs through altering the expression of CSC markers.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.77-90
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• 1996

Nucleocapsid protein (NP)which exists in the particle of hantavirus and surrounds the viral RNA genome is one of the major structural proteins and plays role of antigen to elicit the antibody detected predorminantly right after infection of the virus in the patients of hemorragic fever with renal syndrome (HFRS)or experimental animals. NP is important target antigen in serological diagnostic system of HFRS utilizing whole antigens from the native virus particle, such as IFA, ELISA and Western blotting. Therefore, the preparation of this protein in the level of higher quantity and purity is desirasble for developed dianosis of the disease. The purpose of this study is the cloning of NP gene which exists in the S genome segment of Maaji (MAA) virus and expression of the gene to obtain qualified, genetically engineered NP to be utilized as an immunodiagnostic antigen. First of all, for the purpose of amplifing the MAA-NP gene by PCR, the specific primers were built from the known nucleotide sequence of Hantaan viral NP gene. The viral cDNA of the NP gene was synthesized by using the primers and RNase $H^-$ AMV reverse transcriptase. Thereafter, using this cDNA as a template, the NP gene was amplified specifically by Taq DNA polymrerase. The pT7blue (R)T-overhang vector systems were used for cloning of the amplified NP gene. The expression system was consisted of BL21 (DE3)pLysS and pET16b as a host and a plasmid repectively. Into Ndel site of pET16b, NP gene was ligated with cohesive end for the expression. Insertion of NP gene in the plasmid was confirmed by PCR and mini prep methods. For expression, IPTG was used and the expressed protein was characterized by Western blotting. The MAA-NP was expressed as the form of inclusion body (insoluble fraction)and the protein purified by affinity and metal chealating columns reacted specifically with the sera from patients of HFRS as to be tested by ELISA and Western blotting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.837-843
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• 2013

Sasa borealis is a major source of bamboo leaves used for traditional medicine in Korea. Obesity is a serious health problem in industrialized countries that has been implicated in various diseases, including type 2 diabetes, hypertension, cancer, and coronary heart disease. Recent reports have proposed mechanisms to reduce obesity by decreasing preadipocyte differentiation, and proliferation in 3T3-L1 preadipocyte. The preadipocytes play a key role by differentiation into mature adipocytes and increasing fat mass. In this study, we investigated whether ethanol-soluble extracts and ethyl acetate-soluble fractions from Sasa borealis inhibits intracellular accumulation of lipid droplets in a dose-dependent manner in 3T3-L1 cells (an important model system for studying adipogenesis). The down-regulation of PPAR${\gamma}$ and C/EBP${\alpha}$ (key adipogenic transcription factors) were confirmed by the reverse transcription polymerase chain reaction (RT-PCR). Ethyl acetate-soluble fractions from Sasa borealis attenuated the expression of PPAR${\gamma}$ and C/EBP${\alpha}$. These results suggest that Sasa borealis inhibits adipogenic differentiation by regulating adipogenic transcription factors in 3T3-L1 cells. Therefore, Sasa borealis extracts may be a good candidate for the management of obesity.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6165-6171
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• 2013

This study aimed to analyze the expression and clinical significance of cyclin G2 (CCNG2) in thyroid carcinoma and the biological effects of CCNG2 overexpression in a cell line. Immunohistochemistry and Western blotting were used to analyze CCNG2 protein expression in 63 cases of thyroid cancer and normal tissues to allow the relationship with clinical factors to be assessed. CCNG2 lentiviral and empty vectors were transfected into the thyroid cancer K1 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were applied to detect the mRNA and protein levels of CCNG2. MTT assay and cell cycle were also conducted to assess the influence of up-regulated expression of CCNG2 on K1 cell biology. The level of CCNG2 protein expression was found to be significantly lower in thyroid cancer tissue than normal tissues (P<0.05). Western blot: The relative amount of CCNG2 protein in thyroid cancer tissue was respectively found to be significantly lower than in normal tissues (P<0.05), correlating with lymph node metastasis, clinic stage and histological grade (P<0.05), but not gender, age or tumor size (P>0.05). Loss of CCNG2 expression correlated significantly with poor overall survival time on Kaplan-Meier analysis (P<0.05). The results for biological functions showed that K1 cell transfected CCNG2 had a lower survival fraction, a greater percentage in the G0/G1 phases, and lower cyclin-dependent kinase 2 (CDK2) protein expression compared with K1 cells non-transfected with CCNG2 (P<0.05). CCNG2 expression decreased in thyroid cancer and correlated significantly lymph node metastasis, clinic stage, histological grade and poor overall survival, suggesting that CCNG2 may play important roles as a negative regulator in thyroid cancer K1 cells by promoting degradation of CDK2.

• Journal of Pharmacopuncture
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• v.4 no.1
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• pp.123-124
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• 2001

Purpose. Free radicals are implicated in the pathophysiology of aging, ischemic injury and neurodegenerative disorders. To deform]no whether Hominis Placenta extract prevents $H_2O_2$-induced apoptosis, we have performed morphological and biochemical analyses for the detection of apoptotic phenomena in the pineal tumor cell line $PGT-{\beta}$ We have also peformed cytochemical and immunocytochemical analyses for the detection of changes in nitric oxide synthase (NOS) activity and estimated the expression . of apoptotic genes using reverse transcription-polymerase chain reaction (RT-PCR) Methods. $PGT-{\beta}\;cells$ were pretreated with Hominis Placenta extracts $(0,\;10^{-2}\;{\mu}g/ml)$ for 2 hours and then exposed to $H_2O_2\;(0,\;50\;{\mu}M)$ for 3 hours. Appearance of apoptotic characteristics were monitored using 4, 6-diamidino-2-phenylindole dihydrochloride (DAPI) staining assay, terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay and flow cytometric analysis. NOS activity was measured by NADPH-diaphorase cytochemistry. Expression of inducible NOS (iNOS) and nuclear factor kappa B (NF k B) was assessed via immunocytochemistry. The expression of apoptotic genes was examined by RT-PCR. Results. After 3 flours of exposure to $H_2O_2$, it was shown that $PGT-{\beta}\;cells$ treated with $H_2O_2(50\;{\mu}M)$ exhibit classical apoptotic features and increases in NOS activity and caspase-3 expression. Treatment with Hominis Placenta extract resulted in a reduced occurrence of apoptotic features. DAPI staining, TUNEL and flow cytometric assays revealed decreases in the occurrence of nuclear fragmentation and in the sub-Gl fraction in the $PGT-{\beta}\;cells$ treated with Hominis Placenta extract. Cells treated with Hominis Placenta extract also showed lower activity of NADPH-diaphorase and immunoreactivities of both iNOS and NF k B than those of $H_2O_2$-treated cells which were not treated with Hominis Placenta extract. By RT-PCR, it was shown that the level of caspase-3 mRNA was derreased In the cells treated with Hominis Placenta . extract. Conclusions. This study shows that Hominis Placenta extract prevents $H_2O_2$-induced apoptosis in $PGT-{\beta}\;cells$; inhibitions of iNOS and caspnse-3 are possible mechanisms of the protection against apoptosis.

• Journal of Sensor Science and Technology
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• v.12 no.2
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• pp.66-71
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• 2003

Pt/AlGaN Schottky-type UV photodetectors were designed and fabricated. A low-temperature AlGaN interlayer buffer was grown between the AlGaN and GaN film in the diode structure epitaxy to obtain crack-free AlGaN active layers. A comparison was then made of the structural, electrical, and optical characteristics of two different diodes: one with an AlGaN($0.5\;{\mu}m$)/n+-GaN(2 nm) structure (type 1) and the other with an AlGaN($0.5\;{\mu}m$)/AlGaN interlayer($150\;{\AA}$)/n+-GaN($3\;{\mu}m$) structure(type 2). A crack-free AlGaN film was obtained by the insertion of a low-temperature AlGaN interlayer with an aluminum mole fraction of 26% into the $Al_xGa_{1-x}N$ layer. The fabricated Pt/$Al_{0.33}Ga_{0.67}N$ photodetector had a leakage current of 1 nA for the type 1 diode and $0.1\;{\mu}A$ for the type 2 diode at a reverse bias of -5 V. For the photoresponse measurement, the type 2 diode exhibited a cut-off wavelength of 300 nm, prominent responsivity of 0.15 A/W at 280 nm, and UV-visible extinction ratio of $1.5{\times}10^4$. Accordingly, the Pt/$Al_{0.33}Ga_{0.67}N$ Schottky-type ultraviolet photodetector with an AlGaN interlayer exhibited superior electrical and optical characteristics and improved UV detecting properties.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.94-101
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• 2004

Commercial value of soybean sprouts should be affected by their morphology including the lateral roots. This study was carried out to determine the effect of benzyladenopurine (BA) concentration on growth and morphology of soybean sprouts in order to compare them with the selling products collected from the markets. Four cultivars (cv. Eunhakong, Pungsannamulkong, Sowonkong, and Junjery) were cultured for 6 days after imbibed for 5 hours into different BA solutions (0, 1,2,4, and 8 ppm). On the 6th day, hypocotyl length was measured to calculate the composition rate of ＞ 7 cm (A), 4 to 7 cm (B), ＜ 4 cm (C) and non-germination (D), and the ratio of hypocotyl to root length (H/R ratio) on the base of hypocotyl length as well as lateral root, hypocotyl diameter, and fraction fresh and dry weights. The composition rates classified with hypocotyl length showed big differences between 4 cultivars in class A and C; Class A, in which cv. Sowonkong and Junjery had higher rates than cv. Eunhakong and Pungsannamulkong, was decreased with BA concentration of higher than 4 ppm, but class C showed the reverse result to class A. Any lateral root was not formed in higher than 4 ppm BA solutions although fewer in cv. Pungsannamulkong and Junjery than in the two other cultivars. Hypocotyl and root lengths were decreased with increased BA concentrations, and in all BA concentration, hypocotyl length of cv. Junjery was the longest. Hypocotyl diameter, hypocotyl and total fresh weights were thicker and heavier in 2 to 4 ppm BA concentrations than in the other ones, although in case of BA application, cv, Eunhakong and Sowonkong were heavier. The H/R ratios were increased with increased BA concentration. The ratios of nearly all the selling products ranged from 1 to 2 ppm when compared to them from our experiment.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.111-117
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• 1998

Objectives : 'First-night effect' has been a well-known concept since 1960's. It is important because it is one of the major factors to be considered in assessing the reliability of polysomnographic data. However, 'reverse first-night effect' has also been described, resulting in the inconsistency of conceptualization. We attempted to investigate on the first-night effect in adults by having each of them take two nights of polysomnography in a controlled environment. Young healthy adult volunteers were chosen as subjects in order to rule out age- or health-related confounders. Methods : Polysomnography was performed on eight male medical students (mean $age=23.5\;{\pm}\;0.9$) for two nights with Grass model 78 polysomnograph. We scored manually under the standard protocol each epoch of the sleep records. Sleep variables were obtained and compared between the two nights. Results : Sleep period time(SPT) and total sleep time(TST) of the third fraction of night were significantly longer on the first night than on the second night (p<0.05). However, other sleep variables such as percentage of each sleep stage, sleep latency, REM sleep latency, number of waking, and sleep efficiency were not different between the two nights. Conclusion : We could not confirm the existence of first-night effect in this study. In healthy young male adults, it may not happen at all or may happen to a very negligible degree. Young healthy adults may have more adaptability to a new sleep environment. Also, the provision of a reasonably comfortable sleep environment could have helped them with abolition of first-night effect.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1635-1641
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• 1999

Bacillus subtilis PCA20-3 was isolated from meju and was found to produce a protease. The strain produced the maximum amount of enzyme in the medium containing soytone (0.2%), soluble starch (2%), $(NH_4)_2SO_4\;(0.1%),\;CaCl_2(0.1%),\;yeast\;extract\;(0.01%),\;K_2HPO_4\;(0.1%),\;and\;KH_2PO_4\;(0.1%)$. Protease was first concentrated by ammonium sulfate (80% saturation, w/v) precipitation of culture supernatant. Then the enzyme was purified by column chromatography using CM Sephadex C-50. The collected proteins were rechromatographed using Sephadex G-100 gel filtration column. The fraction with protease active from Sephadex G-100 gel chromatography was found to be pure when examined by SDS-polyacrylamide gel electrophoresis and YMC-pak reverse phase chromatography. Specific activity, yield and purity were 76 U/mg. 2.7%, and 7.6 fold, respectively. The molecular weight of the enzyme was estimated to be 31.5 kDa by SDS-PAGE. The number of amino acids calculated from molecular weight was evaluated about 321 residues. N-terminal sequence of the enzyme was $Val^1-Pro^2-Tyr^3-Gly^4-Val^5-Ser^6-Gln^7-Gly^8-Lys^9-Ala^{10}$.