• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.12
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• pp.1755-1762
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• 1998

In order to minimize emission of polychlorinated dibenzo dioxins and polychlorinated dibenzo furans (PCDD/PCDFs) from municipal solid waste incinerators, it is important to maintain optimized operating conditions along with the system modification/improvement. Operating conditions of MSW incinerator make very complicated influence on formation of PCDD/PCDFs in each unit apparatus. For revealing these influences, concentrations of PCDD/PCDFs are measured from the stack and from the fly ash, while monitoring the plant operating conditions. The effects are grouped into 3 main categories, combustion conditions, de Novo synthesis effects, and adsorption/destruction effects in the flue gas treatment system. Interpretation of the results showed that de Novo synthesis effect, reformation by metalic catalyst, especially Cu in fly ash in the temperature range of $250{\sim}500^{\circ}C$, is found to influence most dominantly on the concentration of PCDD/PCDFs. A plausible mathmatical model for predicting concentration of PCDD/PCDFs is proposed, and discussed.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1569-1576
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• 2013

In mice, supplementation of t10,c12 conjugated linoleic acid (CLA) increases liver mass and hepatic steatosis via increasing uptake of fatty acids released from adipose tissues. However, the effects of t10,c12 CLA on hepatic lipid synthesis and the associated mechanisms are largely unknown. Thus, we tested the hypothesis that gut microbiota-producing t10,c12 CLA would induce de novo lipogenesis and triglyceride (TG) synthesis in HepG2 cells, promoting lipid accumulation. It was found that treatment with t10,c12 CLA ($100{\mu}M$) for 72 h increased neutral lipid accumulation via enhanced incorporation of acetate, palmitate, oleate, and 2-deoxyglucose into TG. Furthermore, treatment with t10,c12 CLA led to increased mRNA expression and protein levels of lipogenic genes including SREBP1, ACC1, FASN, ELOVL6, GPAT1, and DGAT1, presenting potential mechanisms by which CLA may increase lipid deposition. Most strikingly, t10,c12 CLA treatment for 3 h increased phosphorylation of mTOR, S6K, and S6. Taken together, gut microbiota-producing t10,c12 CLA activates hepatic de novo lipogenesis and TG synthesis through activation of the mTOR/SREBP1 pathway, with consequent lipid accumulation in HepG2 cells.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.279.1-279.1
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• 2002

Accumulation of ceramide mass in MCF-7 cells by the anti-cancer agent. paclitaxel. was found to occur primarily due to activation of the de novo synthesis pathway. Morever. the addition of paclitaxel resulted in the accumulation of ceramide, which was followed by a prolonged arachidonic acid release. Participation of ceramide de novo pathway in arachidonate signaling was detected since L-cycloserine, an inhibitor of de novo synthesis, was able to inhibit the paclitaxel-induced AA release and cytotoxicity. (omitted)

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.170.2-171
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• 2000

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.101.1-101.1
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• 2001

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2000.12a
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• pp.48-48
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• 2000

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.181.2-182
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• 2001

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.430-433
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• 1996

The activity of PAL, an initial and key regulatory enzyme in biosynthesis of phenolics, peaked during ripening stage. The enzyme activities were 5.60 and 4.25 units/100g fr. wt. in ripening and overripening stages. The increase in PAL activity in ripening strawberry fruits is due to de novo synthesis of the enzyme. PAL extracts from ripe strawberry fruits have a native molecular weight of about 260, 000 Da.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.105.2-105.2
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• 2003

Recently, several reports suggest that ceramide formation has been implicated in the apoptosis signaling in response to chemotherapeutic agents. In this study, to enhance paclitaxel-mediated cytotoxicity and endogenous ceramide levels, we blocked ceramide metabolism using an inhibitor of glucosylceramide synthase, l-phenyl-2- dacanoylamino-3-morpholino-l-propanol(PDMP) and SM synthase, D609. Exposure of human breast cancer cells to paclitaxel accumulated de novo ceramide synthesis by enhancement of SPT activity 1.2-fold, whereas ceramide synthase activity was not altered. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.184.3-185
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• 2003

Inosine 5'-monophosphate dehydrogenase (IMPDH) is a critical enzyme in the regulation of cell proliferation and differentiation. This enzyme catalyzes the $NAD^+$-dependent oxidation of IMP to XMP, the rate limiting step in de novo biosynthesis of guanine nucleotides. Therefore, the biochemical effect of IMPDH inhibition in sensitive cell types is decrease in intracellular guanine nucleotide levels, and the decrease in cellular GTP and deoxy GTP pool levels blocks DNA and RNA synthesis in rapidly proliferating tumor cells. (omitted)