• Title/Summary/Keyword: chemical induction

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Production of Foamed Glass by Induction Heating Method (인덕션 가열법을 이용한 발포유리제조)

  • Sun, Hongshuai;Yoo, In-Sang
    • Applied Chemistry for Engineering
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    • v.28 no.5
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    • pp.513-520
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    • 2017
  • The application possibility of an alternative new method with low energy consumption was studied for the eco-friendly fabrication of foamed glasses from waste glasses. As a result, fabricating temperature can be reduced under $300^{\circ}C$ without using various expensive inorganic oxidants. The foamed glass can be fabricated at a proper mixing ratio of the waste glass powder, water glass, little surfactant and bubble stabilizer by induction heating method. In the experimental range, the assured optimal condition is 4 min heating on the induction machine with a steel-container ($100mm{\times}100mm{\times}20mm$) and followed by evaporating and drying process for 11 min with 110 g of glass powder, 80 g of water glass, 3 g of surfactant and 0.2 g of bubble stabilizer. When the foamed glass was fabricated at the optimal condition, the density of the glass was $0.85g/cm^3$ and the heat conduction was $0.052W/h{\cdot}K$. In addition, the compressive strength of the glass was above $50kg/cm^2$.

Induction of Cytochrome P45O 1A and 2B by $\alpha$- and ${\beta}-lonone$ in Sprague Dawley Rats

  • Jeong, Tae-Cheon;Jeong, Hye-Gwang;Chun, Yong-Jin;Yun, Chul-Ho;Moon, Chang-Kiu;Lee, Hye-Sook;Han, Sang-Seop;Lee, Eung-Seok
    • Archives of Pharmacal Research
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    • v.25 no.2
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    • pp.197-201
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    • 2002
  • ${\beta}-lonone$ has been reported to induce the cytochrome P45O (P45O) 2B1 in rats. In this study, the effects of ${\beta}-ionone$ and an isomer, ${\alpha}-ionone$, on liver P45O IA and 2B expression in Sprague Dawley rats were investigated . Subcutaneous administration of ${\alpha}-$ and ${\beta}-lonone$ 72 and 48hr prior to sacrificing the animals induced the liver microsomal P45O 1A and 2B proteins. P45O 2Bl induction was associated with the accumulation of its corresponding mRNA. 1 Induction by ${\beta}-lonone$ was much higher than that by ${\alpha}-ionone$-ionone in both the mRNA and protein levels. When the route of administration was compared, P45O 2B was induced more strongly after oral administration compared to that after subcutaneous injection. A single oral dose of 100, 300 and 600 mg/kg of ${\alpha}-$ and ${\beta}-lonone$ for 24 h induced P45O 2B1 -selective pentoxyresorufin Odepentylase activity comparably in a dose-dependent manner In addition, ${\alpha}-$ and ${\beta}-lonone$ induced the P45O 1A and 2B proteins. These results suggest that ${\alpha}-$ and ${\beta}-lonone$ might be potent P45O 2Bl inducers in rats, and that both ionones may be useful for examining the role of metabolic activation in chemical-induced toxicity where metabolic activation is required.

Effective Production of Chitinase and Chitosanase by Streptomyces griseus HUT 6037 Using Colloidal Chitin and Various Degrees of Deacetylation of Chitosan

  • Jung, Ho-Sup;Son, Jeong-Woo;Ji, Hong-Seok;Kim, Kwang
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.26-31
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    • 1999
  • The advantages of the organism Streptomycs griseus HUT 6037 is that the chitinase and chitosanase using chitinaceouse substrate are capable of hydrolyzing both amorphous and crystalline chitin and chitosan. We attempted to investigate the optimization of induction protocol for high-level production and secretion of chitosanase and the influence of chitin and partially deacetylated chitosan sources (75∼99% deacetylation). The maximum specific activity or chitinase has been found at 5 days cultivation with the 48 hours induction time using colloidal chitin as a carbon source. To investigate characteristic of chitosan activity according to substrate, we used chitosan with various degree of deacetylation as a carbon source and found that this strain accumulates chitosanase in the culture medium using chitosanaceous substrates rather than chitinaceous substrates. The highest chitosanase activity was also presented on 4 days with 99% deacetylated chitosan. The partially 53% deacetylated chitosan can secrete both chitinase and chitosanase which was defined as a soluble chitosan. The specific activities of chitinase and chitosanase were 0.89 at 3 days and 1.33 U/mg protein at 5 days, respectively. It indicate that chitosanase obtained from S. griseus HUT 6037 can hydrolyze GlcNAc-GlcN and GlcN-GlcN linkages by exo-splitting manner. This activity increased with increasing degree of deacetylation of chitosan. It is the first attempted to investigate the effects of chitosanase on various degrees of deacetylations of chitosan by S. griseus HUT 6037. The highest specific activity of chitosanase was obtained with 99% deacetylated chitosan.

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chemopreventive Effects of 2-(Allylthio) pyrazine

  • Kim, Nak-Doo;Kim, Sang-Geon
    • Archives of Pharmacal Research
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    • v.22 no.2
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    • pp.99-107
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    • 1999
  • A series of organosulfur compounds were synthesized with the aim of developing chemopreventive compounds active against hepatotoxicity and chemical carcinogesis. 2-(Allylthio) prazine (2-AP) was effective in inhibiting cytochrome P450 2E1-mediated catalytic activities and protein expression, and in inducing microsomal epoxide hydrolase and major glutathione S-transferases. 2-AP reduced the hepatotoxicity caused by toxicant sand elevated cellular GSH content. Development of skin tumors, pulmonary adenoma and aberrant crypt foci in colon by various chemical carcinogens was inhibited by 2-AP pretreatment. Anticarcinogenic effects of 2-AP at the stage of initiation of tumors were also observed in the aflatoxin B1 ($AFB_1$)-induced three-step medium-term hepatocarcinogenesis model. Reduction of $AFB_1$-DNA adduct by 2-AP appeared to result from the decreased formation of $AFB_1$-8,9-epoxide via suppression of cytochrome P450, while induction of GST 2-AP increases the excretion of glutathione-conjugated $AFB_1$ . 2-AP was a radioprotective agent effective against the lethal dose of total body irradiation and reduced radiation-induced injury in association with the elevation of detoxifying gene expression. 2-AP produces reactive oxygen species in vivo, which is not mediated with the thiol-dependent production of oxidants and that NF-KB activation is not involved in the induction of the detoxifying enzymes. the mechanism of chemoprotection by 2-AP may involve inhibition of the P450-mediated metabolic activation of chemical carcinogens and enhancement of electrophilic detoxification through induction of phase II detoxification enzymes which would facilitate the clearance of activated metabolites through conjugation reaction.

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Induction and Proliferation of Callus in Rhus chinensis Mill. and Its Effect on Skin Whitening (붉나무 캘러스 유도 및 그 추출물로부터 피부미백 효과에 관한 연구)

  • Kim, Dong-Myong;Jung, Ju-Yeong;Lee, Hyung-Kon;Kwon, Yong-Seong;Baek, Jin-Hong;Lee, Kwan-Ho;Jang, Jin-Hoon;Han, In Suk
    • Korean Journal of Pharmacognosy
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    • v.51 no.4
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    • pp.302-309
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    • 2020
  • The objective of this study was to optimize the condition for induction and proliferation of callus from Rhus chinensis Mill. and investigate the skin-brightening effect of Rhus chinensis callus (RCC). It was confirmed that the most proper plant growth regulator (PGR) for callus induction is 1.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). The most optimal condition of PGR, medium and additives for callus proliferation were 2,4-D (1.0 mg/L), MS medium and citric acid, respectively. Inhibitory activities of tyrosinase were higher at 50 and 100 ㎍/mL of RCC extracts (41.86 and 75.56%, respectively) than arbutin (27.32%). As the results of measuring melanin inhibition in B16F1 melanocyte and B16F10 melanoma cell, RCC extracts increased its inhibitory activities concentration-dependently, and were found to have higher whitening effect than arbutin at a concentration of 100 ㎍/mL. Therefore, it is suggested that RCC can be used as an effective material for skin-brightening cosmetics.

Alkenylation of o-xylene with 1,3-Butadiene Over Base Catalysts (염기성 촉매를 이용한 o-xylene과 1,3-Butadiene의 알케닐화 반응)

  • Lee, Jong Seok;Lee, Soo Chool;Kil, Min Ho;Choi, Il Seok;Lee, Jae Sung;Kim, Jae Chang
    • Korean Chemical Engineering Research
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    • v.40 no.6
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    • pp.669-675
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    • 2002
  • The alkenylation of o-xylene with 1,3-butadiene to make OTP(ortho-tolyl Pentene) was carried out over liquid phase NaK alloy, Na metal and the metallic sodium dispersed on the specific support such as NaX and $Al_2O_3$. Liquid phase NaK alloy showed the improved conversion and selectivity when they were pretreated by ultrasound to increase the dispersion. For the case of metallic sodium, the induction period for the formation of homogeneous metal sodium solution with high dispersion was needed before the reaction. In the case of metallic sodium dispersed on support, more than 80 % conversion could be obtained without induction period regardless of supports used. But 85 % of the metallic sodium was resolved into the reaction mixture after reaction for 7 hours. The amount of byproducts, oligomers, produced from OTP and 1,3-butadiene increased with the amount of 1,3-butadiene introduced and the selectivity to OTP was in inversely proportional to the conversion.

GCP (GENISTEIN CONCENTRATED POLYSACCHARIDE): A SOYBEAN ISOFLAVONE DIETARY SUPPLEMENT FERMENTED BY BASIDIOMYCETES WITH ANTI CARCINOGENIC ACTIVITIES: THEIR MOLECULAR MECHANISMS AND CHEMOPREVENTIVE POTENTIAL

  • Lan Yuan;Takehito Miura;Mayumi Yoshida;Chihiro Wagatsuma;Hajime Fujii;Tomomi Mukoda;Sun, Bu-Xiang;Kenichi Kosuna
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.15-16
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    • 2001
  • GCP is a novel functional food obtained from the extracts of soybean isoflavone fermented with basidiomycetes mycelia. The enzyme reaction makes GCP containing high concentration of isoflavone aglycons, particularly for genistein and high content of polysaccharides. GCP exerts its anti-tumor activities by anti-angiogenesis and induction of apoptosis in cancer tissues and by enhancement of immune responses in immune system.(omitted)

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A Study on the Tolerance Band of Voltage Drop during Motor Startup for Refineries and Chemical Plants with Isolated Power Systems

  • Shin, Ho-Jeon;Cho, Man-Young;Chun, Hong-Il;Kim, Jin-Seok
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.486-493
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    • 2017
  • Refineries and chemical plants with isolated power systems that have a limited power supply are more susceptible to voltage changes from disturbances compared to power systems connected with a power company. Furthermore, most loads in such cases are induction motor loads, and therefore, transient voltage characteristics when starting a high-capacity motor must be examined. In general, high-capacity motors are customized appropriately to the load performance curve by the manufacturer during the construction of an industrial plant. Subsequently, when complying with the voltage drop permitted by international standards during the design process, power supply equipment such as transformers and generators is overdesigned. Therefore, a novel analysis is necessary on standards for startup and constraint voltage drops, as well as on identifying the voltage drop limitations for starting high-capacity motors in refineries and chemical plants with isolated power systems. In this study, field tests on an industrial plant were conducted, and simulations modeled under conditions identical to those of the field test system were performed using the general-purpose program ETAP in order to compare the results.

Development of a Sensitive Bioassay Method for Quorum Sensing Inhibitor Screening Using a Recombinant Agrobacterium tumefaciens

  • Kim Yeon Hee;Kim Young Hee;Kim Jung Sun;Park Sunghoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.4
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    • pp.322-328
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    • 2005
  • Acylhomoserine lactones (AHLs) are known to be the triggering molecules in the quorum sensing mechanism of many gram-negative bacteria. In order to detect AHL inhibitors that are potential biofilm inhibitors, a convenient and sensitive bioassay was developed based on the $\beta$-galactosidase activity ($\beta$-GAL) of a recombinant Agrobacterium tumefaciens strain. A series of commercially available AHLs were tested for inducing $\beta$-GAL at varying concentrations in agar-plate and liquid cultures of the reporter strain. All AHLs tested exhibited a concentration­dependent induction, and octanoyl homoserine lactone (OHL) showed the highest sensitivity with a detection limit of 0.1 nM in the liquid culture assay. When fimbrolide, a known quorum sensing inhibitor, was added, induction of $\beta$-GAL by OHL was repressed. The repression at a constant OHL concentration was dependent on the fimbrolide concentration with the detection limit below 1 ppm, indicating that this assay is a sensitive method for screening AHL inhibitors.

Differential Induction of Protein Expression and Benzophenanthridine Alkaloid Accumulation in Eschscholtzia californica Suspension Cultures by Methyl Jasmonate and Yeast Extract

  • Cho, Hwa-Young;Rhee, Hong-Soon;H. Yoon, Sung-Yong;Park, Jong-Moon
    • Journal of Microbiology and Biotechnology
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    • v.18 no.2
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    • pp.255-262
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    • 2008
  • Methyl jasmonate (MJ) and yeast extract (YE) induce protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cell cultures. One hundred ${\mu}M$ MJ primarily induced dihydrosanguinarine $(509.0{\pm}7.4mg/l)$ ; 0.2g/l YE induced sanguinarine $(146.8{\pm}3.8mg/l)$ and an unknown compound. These results occur because dihydrobenzophenanthridine oxidase (DHBO) is induced by YE and not by MJ. YE and chitin (CHI) had similar effects on sanguinarine production and DHBO expression. Differential induction of secondary metabolites was shown in E. californica suspension cultures and the expression of proteins confirmed the metabolite results. Furthermore, treatment by various oligosaccharides helped us to understand the elicitation effect of YE in signal transduction pathways.