• Molecules and Cells
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• v.38 no.4
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• pp.373-379
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• 2015

Pyruvate kinase M2 isoform (PKM2), a rate-limiting enzyme in the final step of glycolysis, is known to be associated with the metabolic rewiring of cancer cells, and considered an important cancer therapeutic target. Herein, we report a novel PKM2 activator, PA-12, which was identified via the molecular docking-based virtual screening. We demonstrate that PA-12 stimulates the pyruvate kinase activity of recombinant PKM2 in vitro, with a half-maximal activity concentration of $4.92{\mu}M$, and effectively suppresses both anchorage-dependent and -independent growth of lung cancer cells in non-essential amino acid-depleted medium. In addition, PA-12 blocked the nuclear translocalization of PKM2 in lung cancer cells, resulting in the inhibition of hypoxia response element (HRE)-mediated reporter activity as well as hypoxia-inducible factor 1 (HIF-1) target gene expression, eventually leading to the suppression of cell viability under hypoxia. We also verified that the effects of PA-12 were dependent on PKM2 expression in cancer cells, demonstrating the specificity of PA-12 for PKM2 protein. Taken together, our data suggest that PA-12 is a novel and potent PKM2 activator that has therapeutic implications for lung cancer.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.197-203
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• 1993

Screenings were performed on edible plants to examine their complement-system activating ability (anti-complementary activity) by hemolytic complement assay $(TCH_{50})$. Among 38 kinds of plant extracts, 5 kinds showed relatively strong anti-complementary activity which decreased $TCH_{50}$ more than 60% comparison with control and the order of activity was Zingiber officinale>Colocasia antiquorum>Capsella bursapastoris>Ginkgo biloba>Alium monanthum in $1000{\mu}g/ml$. The anti-complementary activity of ZR-1 prepared from the root of Zingiber officinale which was showed the most potent activity, did not change by pronase treatment, but decreased greatly by periodate oxidation. These results indicate that not protein moiety but carbohydrate moiety in ZR-1 fraction may also contribute to the anti-complementary activity. Also, the anti-complementary activity of ZR-1 was reduced partially in the absence of the $Ca^{2+}$ ion. When crossed immunoelectrophoresis using anti-human C3 serum was carried out after incubation of normal human serum with the ZR-1 in $Ca^{2+}$ free condition, a cleavage of C3 precipitin line was observed. Furthermore this polysaccharide fraction considerably inhibited $ACH_{50}$. These results also indicate that the mode of complement activation by polysaccharide from Zingiber officinale is via not only the classical pathway but also the alternative pathway.

• Journal of Gifted/Talented Education
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• v.26 no.1
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• pp.211-230
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• 2016

The study aimed to investigate the characteristics of algebraic thinking of the mathematically gifted students and search for how to teach algebraic thinking. Research subjects in this study included 93 students who applied for a science gifted education center affiliated with a university in 2015 and previously experienced gifted education. Students' responses on an algebraic item of a creative thinking test in mathematics, which was given as screening process for admission were collected as data. A framework of algebraic thinking factors were extracted from literature review and utilized for data analysis. It was found that students showed difficulty in quantitative reasoning between two quantities and tendency to find solutions regarding equations as problem solving tools. In this process, students tended to concentrate variables on unknown place holders and to had difficulty understanding various meanings of variables. Some of students generated errors about algebraic concepts. In conclusions, it is recommended that functional thinking including such as generalizing and reasoning the relation among changing quantities is extended, procedural as well as structural aspects of algebraic expressions are emphasized, various situations to learn variables are given, and activities constructing variables on their own are strengthened for improving gifted students' learning and teaching algebra.

• Journal of Microbiology
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• v.44 no.3
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• pp.301-310
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• 2006

Two pathways of ammonium assimilation and glutamate biosynthesis have been identified in microorganisms. One pathway involves the NADP-linked glutamate dehydrogenase, which catalyzes the amination of 2-oxoglutarate to form glutamate. An alternative pathway involves the combined activities of glutamine synthetase, which aminates glutamate to form glutamine, and glutamate synthase, which transfers the amide group of glutamine to 2-oxoglutarate to yield two molecules of glutamate. We have cloned the large subunit of the glutamate synthase (GOGAT) from Salmonella typhimurium by screening the expression of GOGAT and complementing the gene in E. coli GOGAT large subunit-deficient mutants. Three positive clones (named pUC19C12, pUC19C13 and pUC19C15) contained identical Sau3AI fragments, as determined by restriction mapping and Southern hybridization, and expressed GOGAT efficiently and constitutively using its own promoter in the heterologous host. The coding region expressed in Escherichia coli was about 170 kDa on SDS-PAGE. This gene spans 4,732 bases, contains an open reading frame of 4,458 nucleotides, and encodes a mature protein of 1,486 amino acid residues (Mr =166,208). The EMN-binding domain of GOGAT contains 12 glycine residues, and the 3Fe-4S cluster has 3 cysteine residues. The comparison of the translated amino acid sequence of the Salmonella GOGAT with sequences from other bacteria such as Escherichia coli, Salmonella enterica, Shigella flexneri, Yersinia pestis, Vibrio vulnificus and Pseudomonas aeruginosa shows sequence identity between 87 and 95%.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.190-204
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• 2010

This study firstly examined the socioeconomic and health factors associated with infiltration of private health insurance. Secondly, we compared health behavior, outpatient and inpatient use of private health insured with uninsured. The method of this study is that secondary analysis of the 2008 Korea National Health and Nutrition Survey was conducted for 7178 respondents aged 19 over. We use the logistic regression and t-test for data analysis. The first dependent variable was dichotomy which is divided to private health insured or uninsured and the second dependent variable was the presence and frequency of outpatient and inpatient use. The descriptive variables was gender, age, marital status, income, education, occupation, type of national health insurance, residential area, self confidence of health, prevalence rate of common disease, activity limitation, drinking and smoking status. The result of the major findings are as follows. First, 59 under aged person, married person, people in the higher brackets of income, national employee insured were more likely to infiltrate private health insurance. The poor self confidence of health, activity limitation, person with hypertension or allergic rhinitis and smoker were negatively related in infiltrating private health insurance. Second, private health insured did more preventive behavior such as self-paid health examination, cancer screening, regular exercise than uninsured. Third, private health insured was positively related with the presence of outpatient use and frequency of inpatient use

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.331-337
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• 1998

The biological activities of both ethanol and water extracts from the fruiting body of E. applanata and E. applanata mycelium and the three fractions of ethanol extracts from E. applanata were compared. 91% of MCF7 cell growth was inhibited by adding 0.5 g/l of water extracts of E. applanata and 81% of MCF7 cell growth was inhibited by adding 0.5 g/l of diethyl ether and chloroform fractions. It was also showed that above 60% of Hep3B cell growth was inhibited by adding all samples including the fractions. The ethanol extracts of E. applanata mycelium showed 33.3% of cytotoxicity on normal liver cell, WRL68 in adding 0.5 g/l of the samples and 40% in adding 0.5 g/l of chloroform fractions. The result of anti-mutagenicity of all extracts and fractions including ethanol extracts of Phelinus linteus were showed that diethyl ether fractions were most effective than any other samples. Hypoglycemic activities of diethyl ether and chloroform fractions were the most effective which scores were above 75%. The enhancement of glutathione-S-transferase activity was increased above 2.3 times by adding 1.0 g/l ethanol extracts of E. applanata and diethyl ether, chloroform fractions. It can be concluded that both biological activities of the fruiting body and mycelium of E. applanata were almost equivalent.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.238-244
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• 2011

Biodiesel, mono-alkyl esters of long chain fatty acids, is one of the alternative fuels derived from renewable lipid feedstock, such as vegetable oils or animal fats. For decade, various lipases have been used for the production of biodiesel. However, the production of biodiesel by enzymatic catalyst has profound restriction in industry application due to high cost. To overcome these problems, many research groups have studied extensively on the selection of cheap oil sources, the screening of suitable lipases, and development of lipase immobilization methods. In this study, we produced biodiesel from plant oil using Proteus vulgaris lipase K80 expressed in Escherichia coli cells. The recombinant lipase K80 was not only expressed in high level but also had high specific lipase activity and high stability in various organic solvents. Lipase K80 could produce biodiesel from olive oil by 3-stepwise methanol feeding method. The immobilized lipase K80 also produced biodiesel using the same 3-stepwise method. The immobilized lipase could produce biodiesel efficiently from various plant oils and waste oils.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.315-321
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• 2010

Malassezia furfur is an important causal factor for seborrheic dermatitis. Nowadays, the drugs available to treat this fungal infection are few. Several studies have documented the biological activity of essential oils. However, its antifungal properties are not completely understood, especially its anti-Malassezia activity. The aim of this study were to evaluate the effect of the plant essential oils on the growth of M. furfur using disk diffusion method and analyze by Gas chromatography-mass spectrometry (GC-MS) most active essential oils. In first screening, the 17 plant essential oils have possesses inhibitory activity against M. furfur at 2 mg/mL. Among the plant essential oils, oil of Citrus auranifoli was most active against M. furfur and its activity showed dose dependency. This anti-malassezial activity was high than that of itraconazole at 2 mg/mL. Oil of Citrus auranifolia also was phytochemically examined by GC-MS analysis, its main constituents were identified as limonene, ${\gamma}$-terpinene and terpinolene. It can be concluded that essential oils of Citrus auranifolia may have interesting applications to control fungal-derived diseases.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.373-378
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• 2010

Studies on standardization and quality upgrade of nuruk which is a basic component in brewing are required to increase the quality level of Korean traditional rice wines and to develop the technology for practical use of it. It is important to isolate best strains, to improve the properties and effectively preserve them for brewing industry. In this study, 16 commercial nuruk samples were obtained from the commercial markets located in Chungcheong areas in Korea. 174 fungal strains were isolated from the samples on DG18 medium using a dilution plating method and then screened for enzyme activity and acid production. The active strains were identified based on the morphological characteristics and ITS sequence analysis. Out of 174 strains, 12 strains showed high amylase activity. Especially, Rhizopus sp. CN084, CN174, Aspergillus sp. CN161 and Mycocladus sp. CN042 showed high saccharogenic power and dextrinogenic enzyme activity on cooked wheat bran medium. On the other hand, Aspergillus sp. CN010, CN161, Rhizopus sp. CN105, CN168 and Rhizomucor sp. CN088 produced high acid production on the same medium. Our results showed that the active strains may be used as microbial sources for nuruk starter with good quality in brewing.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.323-328
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• 2006

The purpose of this paper was to investigate the reforming characteristics and optimum operating condition of the GlidArc-assisted $C_3H_8$ reforming reaction for the synthesis gas(SynGas) production without formation of carbon black from propane using GildArc plasma reforming. Also, in order to increase the hydrogen production and the propane conversion rate, 13 wt % nickel catalyst was filled into the catalytic reactor and parametric screening studies were conducted, in which there were the variations of vapor mole ratio$(H_2O/C_3H_8),\;CO_2$ mole ratio($CO_2/C_3H_8$), input power and injection flow rate. When the variations of vapor mole ratio, $CO_2$ mole ratio, input power and injection flow rate were 1.86, 0.48, 1.37 kW and 14 L/min, respectively, the conversion rate of the propane reached its most optimal condition, or 62.6%. Under the condition mentioned above, the dry basic concentrations of the SynGas were $H_2\;44.4%,\;CO\;18.2%,\;CH_4\;11.2%,\;C_2H_2\;2.0%,\;C_3H_6\;1.6%,\;C_2H_4\;0.6%\;and\;C_3H_4$ 0.4%. The conversion rate of carbon dioxide was 29.2% and the concentration ratio of hydrogen to carbon monoxide($H_2/CO$) in the SynGas was 2.4.