• Title/Summary/Keyword: ${\gamma}'$ phase

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Preparation of High-capacity Ceramic Catalytic Support from Gibbsite (깁사이트를 이용한 고기능 세라믹 촉매담체의 제조)

  • Park, Byung-Ki;Suh, Jeong-Kwon;Lee, Jung-Min;Suhr, Dong-Soo
    • Journal of the Korean Ceramic Society
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    • v.39 no.3
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    • pp.245-251
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    • 2002
  • We prepared γ-alumina beads using the amorphous alumina, obtained by fast calcination of gibbsite, and its were immersed in aqueous solution of the mixture of 21.87% nitric acid and 28.57% acetic acid. The beads thus were hydrothermaly treated at 200$^{\circ}$C for 3h, and were investigated changes of crystal, pore characteristics, $N_2$ adsorption and desorption isotherms, mechanical strengths and thermal resistance. Acicular platelet crystals of 0.1∼0.3${\mu}$m were transformed into acicular boehmite crystals of 1∼2${\mu}$m having the same crystal structure. Through this changes, we found that reversible phase transformation due to hydrothermal reaction took placed between boehmite and ${\gamma}$-alumina. In comparison to the ${\gamma}$-alumina bead before hydrothermal treatment, $N_2$ adsorption capacity was increased from 450㎖/g to 670㎖/g, and pore volume between 100${\AA}$ and 1000${\AA}$ was increased form 0.15㎖/g to 0.77㎖g, and mechanical strength was increased form 1.4MPa to 2.2MPa. Also, it showed the remarkable thermal resistance which sustained ${\theta}$-alumina crystal structure and pores between 100${\AA}$ and 1000${\AA}$ at 1000$^{\circ}$C in 40vol% steam.

ACE Inhibitory Lignan Glycosides Isolated from Eucommia ulmoides Oliver (두충으로부터 분리한 Iignan glycoside 의 ACE 활성 억제)

  • Joo, Ok-Soo;Nam, Sang-Hae
    • Journal of Life Science
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    • v.19 no.6
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    • pp.698-704
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    • 2009
  • To evaluate a potential possibility of Eucommia ulmoides Oliver as a functional food, ACE (angiotensin converting enzyme) inhibitory activities of leaf, bark, stem and 4 compounds isolated from E. ulmoides were tested. The 4 compounds were isolated and purified by silica gel column chromatography, thin layer chromatography and reverse phase column chromatography. Compound I was pinoresinol-4,4'di-O-${\beta}$-D-glucoside (PG) and compound II was dehydrodiconiferyl alcohol 4,${\gamma}$'-di-O-${\beta}$-D-glucopyranoside (DAG) originating from Eucommial Cortex. The highest amount of PC was present at raw and roasted bark as 135.13 mg% and 163.67 mg%, and the highest amount of DAG was present at raw and roasted leaf as 117.93 mg% and 133.93 mg% respectively. In an ACE inhibition test, 10 mg/ml of roasted leaf, raw and roasted bark extracts of E. ulmoides Oliver were 77.49%, 75.72% and 75.36% respectively, and 10mg/ml of PC and DAG were shown to be 78.51 and 81.20% respectively. $IC_{50}$ values of PG and DAG were 0.6${\pm}$0.2 and 0.5${\pm}$0.2 mg/ml respectively.

Radioprotective Effect of Methylene Blue 1. Effect of Methylene Blue on Lactic Dehydrogenase Level and Lactic Dehydrogenase Isoenzymes of Rats Exposed to Gamma-Irradiation (Methylene Blue의 방사선 방어결과 1. Methylene Bluerk가 $\gamma$선에 조사된 흰쥐의 유산탈수소효소의 함량과유산탈수소효소의 동위효소에 미치는 영향)

  • Sang Yul Nam;Seung Han Chang
    • The Korean Journal of Zoology
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    • v.12 no.3
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    • pp.94-102
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    • 1969
  • The protective action of methylene blue against gamma-irradiation was studied with rats. Albino rats were given 360 rads of whole-body gamma-irradiation following an intraperitoneal injection of physiological saline or methylene blue. Male rats given methylene blue (38mg/kg) and the control rats given saline were alive following gamma-irradiation. Serum lactic dehydrogenase (LDH) activity, and LDH isoenzyme patterns in serum and various organs were determined at various time intervals after the exposure. 1) The serum LDH level in both the control and methylene blue-treated rats was increased during the initial phase, but returned to the initial level thereafter. 2) Methylene blue showed a marked delay in the rise of serum LDH at 15 and 64 hours after exposure. 3) The exposure in the control and methylene blue-treated rats resulted in an increase in the relative amount of the more electrophoretically mobile-anodal isoenzyme (band 1) and a decrease in the least mobile-cathodal isoenzyme (band 5) in serum, liver, heart and testis nearly at 40 and 116 hours, respectively. 4) Isoenzyme patterns in serum, liver and testis after exposure were not significantly different between the control and the methylene blue-treated rats. 5) Methylene blue showed a slight delay in alteration of heart tissue LDH isoenzyme patterns after exposure. 6) The increase of serum LDH level after exposure is a reflection of an immediate increase in the H type, band 1 of LDH isoenzymes. 7) It is concluded from this study that methylene blue has a remarkable radioprotective action in the serum LDH activity and in the heart tissue LDH isoenzyme patterns.

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Determination of Tocopherol and Tocotrienol Contents in Rice Cooked with Various Cereals (밥의 종류에 따른 토코페롤 및 토코트리에놀 함량 분석 -연구노트-)

  • Kim, Yangsoo;Park, Soonriang;Lee, Young-Sang;Jung, Hwan;Koh, Kwangoh;Kim, Hee-Seon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1289-1292
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    • 2005
  • The objective of this study was to characterize and determine contents of vitamin E isomers (alpha-, beta-, gamma-, delta-tocopherols and tocotrienols) in different steamed rice dishes, with or without other grains. Five different rice dishes were evaluated for the vitamin E nutritional value as major Korean staple foods. They were plain steamed rice (SR) and steamed rice mixed with barley (SRBa), red bean (SRRB), black bean (SRBB), or multi-grains (SRMG) containing a mixture of black rice, barley, red beans, and black beans. Vitamin E isomers were extracted from five grams of freeze-dried samples with hexane after saponification. An analytical method, using a normal-phase HPLC with a UV detector, was developed and used to determine the amount of each vitamin E component. The results showed that SR contained three vitamin E isomers (alpha-tocopherol, alpha-tocotrienol, and gamma-tocotrienol). Alpha-tocopherol and gamma-tocotrienol were de-tected from all samples while only SRBB contained beta-tocopherol and beta-tocotrienol. SRMG showed the highest (3.9$\mu$g/g dry wt) and SRRB showed the lowest alpha-tocopherol (1.3$\mu$g/g dry wt) contents. SRBB contained about 5 to 16 times more gamma-tocopherol (19.7$\mu$g/g dry wt) than othe.5. These results suggested that adding black bean or multi-grains can dramatically improve the vitamin E nutritional values compared to the plain steamed rice (SR). Information obtained from this study can be directly related to the amount of vitamin E intake and can be used to balance the diet for Koreans.

Effect of Manganese Content on the Magnetic Susceptibility of Ferrous-Manganese Alloys: Correlation between Microstructure on X-Ray Diffraction and Size of the Low-Intensity Area on MRI

  • Youn, Sung Won;Kim, Moon Jung;Yi, Seounghoon;Ahn, Hyun Jin;Park, Kwan Kyu;Lee, Jongmin;Lee, Young-Cheol
    • Investigative Magnetic Resonance Imaging
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    • v.19 no.2
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    • pp.76-87
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    • 2015
  • Purpose: There is an ongoing search for a stent material that produces a reduced susceptibility artifact. This study evaluated the effect of manganese (Mn) content on the MRI susceptibility artifact of ferrous-manganese (Fe-Mn) alloys, and investigated the correlation between MRI findings and measurements of Fe-Mn microstructure on X-ray diffraction (XRD). Materials and Methods: Fe-Mn binary alloys were prepared with Mn contents varying from 10% to 35% by weight (i.e., 10%, 15%, 20%, 25%, 30%, and 35%; designated as Fe-10Mn, Fe-15Mn, Fe-20Mn, Fe-25Mn, Fe-30Mn, and Fe-35Mn, respectively), and their microstructure was evaluated using XRD. Three-dimensional spoiled gradient echo sequences of cylindrical specimens were obtained in parallel and perpendicular to the static magnetic field (B0). In addition, T1-weighted spin echo, T2-weighted fast spin echo, and $T2^*$weighted gradient echo images were obtained. The size of the low-intensity area on MRI was measured for each of the Fe-Mn binary alloys prepared. Results: Three phases of ${\alpha}^{\prime}$-martensite, ${\gamma}$-austenite, and ${\varepsilon}$-martensite were seen on XRD, and their composition changed from ${\alpha}^{\prime}$-martensite to ${\gamma}$-austenite and/or ${\varepsilon}$-martensite, with increasing Mn content. The Fe-10Mn and Fe-15Mn specimens comprised ${\alpha}^{\prime}$-martensite, the Fe-20Mn and Fe-25Mn specimens comprised ${\gamma}+{\varepsilon}$ phases, and the Fe-30Mn and Fe-35Mn specimens exhibited a single ${\gamma}$ phase. The size of the low-intensity areas of Fe-Mn on MRI decreased relative to its microstructure on XRD with increasing Mn content. Conclusion: Based on these findings, proper conditioning of the Mn content in Fe-Mn alloys will improve its visibility on MR angiography, and a Mn content of more than 25% is recommended to reduce the magnetic susceptibility artifacts on MRI. A reduced artifact of Fe-Mn alloys on MRI is closely related to the paramagnetic constitution of ${\gamma}$-austenite and/or ${\varepsilon}$-martensite.

Effect of Gamma Irradiation on the Expression of Gene Endoding Metalloprotease in Vibrio vulnificus (감마선 조사가 vibrio vulnificus의 Metalloprotease 유전자 발현에 미치는 영향)

  • Jung, Jin-Woo;Lim, Sang-Yong;Joe, Min-Ho;Yun, Hye-Jeong;Hur, Jung-Mu;Kim, Dong-Ho
    • Microbiology and Biotechnology Letters
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    • v.36 no.1
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    • pp.6-11
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    • 2008
  • To check the microbiological safety with respect to increased virulence of surviving pathogens after irradiation, in this study, the transcriptional change of vvp gene encoding metalloprotease, which is one of the typical virulence factors of Vibrio mulnificus, was monitored by real-time PCR during the course of growth cycle after reinoculation of irradiated Vibrio. When V. vulnificus was exposed to a dose of 0.5 and 1 kGy, the lag period before growth resumption of sub-cultures became longer than non-irradiated counterpart as increase of irradiation dose. In the case of non-irradiated culture, the transcription of vvp was significantly activated at 15 h after inoculation, when bacterial growth reached the stationary phase, and the highest level of pretense activity (686 U/mL) was measured at the same time. Interestingly, vvp expression of irradiated Vibrio was turned up earlier than non-irradiated Vibrio during the mid log phase of growth, whereas these rapid induction of vvp expression from irradiated cells didn't result in an increase of metalloprotease production. When Vibrio was irradiated at 0.5 and 1 kGy, the protease activities peaked at 18 h after inoculation and the levels of activities were lower 1.2- and 1.4-fold, respectively, compared to the non-irradiated counterpart. Results from this study indicate that gamma radiation is not likely to activate the virulence ability of surviving Vibrio.

Study on the Nicotine-Degrading Bacteria(2) -The Optimal Growth Condition of Nicotinophiles- (니코틴 분해 세균에 관한 연구(2) -니코틴 분해 세균의 최적 생장조건 연구-)

  • 강은희
    • Journal of the Korean Society of Tobacco Science
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    • v.2 no.2
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    • pp.20-37
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    • 1980
  • Among the 34 strains of Nicotinophiles selected in the previous experiments, strain NCT27 identified with Pseudomonas putida and strain NCT30 identified with Arthrobacter oxydans biotype nan thus were Investigated for optimization of growth conditions for nicotine degradation and other cultural characteristics. The compositions of optimized medium were to be following: $KH_2PO_4$ 2.Ogr, KCI 5.Ogr, $MgSO_4$.$7H_2O$ 20mg, $MnSO_4$.$6H_2O$ 0.2mg, $FeSO_4$.$7H_2O$ 1.Omg, Col$^{++}$ (Cobalt Acetate),2.O$\gamma$, N1$^{++}$ (NiSO4,6H2O) 0.5$\gamma$, and yeast extract 80mg per liter. The optimum initial concentrations of nicotine for growth were 0.4% for Pseudomonas and 0.1% for Arthrobacter, respectively. The optimum temperature and pH were 3$0^{\circ}C$ and 7.0 for both of strains. The pH of culture medium of Pseudomonas was changed from acidic condition to basic one in going from the logarithmic growth phase to the stationary growth phase. In contrast with Pseudomonas, it remained constant in case of Arthrobacter. The growth of Arthrobacter was completely inhibited in the nicotine concentration of 0.7&. However, Pseudomonas could grow even in the nicotine concentration of 1.0%. Moreover, it could grow successfully in the tobacco extract media as well as media containing carbon and nitrogen sources other than nicotine. The maximum rates of nicotine degradation were to be 1.22 gr./hr./liter for Pseudomonas and 0.186 gr./hr./liter for Arthrobacter, respectively.

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Anti-obesity effect of EGCG and glucosamine-6-phosphate through decreased expression of genes related to adipogenesis and cell cycle arrest in 3T3-L1 adipocytes (Adipogenesis관련 유전자발현감소와 Cell Cycle Arrest를 통한 EGCG와 Glucosamine-6-Phosphate의 Anti-Obesity 효과)

  • Kim, Kkot Byeol;Jang, Seong hee
    • Journal of Nutrition and Health
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    • v.47 no.1
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    • pp.1-11
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    • 2014
  • Purpose: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. Methods: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expres-sion level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. Results: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG $60{\mu}M$ and PGlc $200{\mu}g/m$ compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. Conclusion: Combination treatment of EGCG and PGlc inhibited adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.

In vivo Pharmacokinetics, Activation of MAPK Signaling and Induction of Phase II/III Drug Metabolizing Enzymes/Transporters by Cancer Chemopreventive Compound BHA in the Mice

  • Hu, Rong;Shen, Guoxiang;Yerramilli, Usha Rao;Lin, Wen;Xu, Changjiang;Nair, Sujit;Kong, Ah-Ng Tony
    • Archives of Pharmacal Research
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    • v.29 no.10
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    • pp.911-920
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    • 2006
  • Phenolic antioxidant butylated hydroxyanisole (BHA) is a commonly used food preservative with broad biological activities, including protection against chemical-induced carcinogenesis, acute toxicity of chemicals, modulation of macromolecule synthesis and immune response, induction of phase II detoxifying enzymes, as well as its undesirable potential tumor-promoting activities. Understanding the molecular basis underlying these diverse biological actions of BHA is thus of great importance. Here we studied the pharmacokinetics, activation of signaling kinases and induction of phase II/III drug metabolizing enzymes/transporter gene expression by BHA in the mice. The peak plasma concentration of BHA achieved in our current study after oral administration of 200 mg/kg BHA was around $10\;{\mu}M$. This in vivo concentration might offer some insights for the many in vitro cell culture studies on signal transduction and induction of phase II genes using similar concentrations. The oral bioavailability (F) of BHA was about 43% in the mice. In the mouse liver, BHA induced the expression of phase II genes including NQO-1, HO-1, ${\gamma}-GCS$, GST-pi and UGT 1A6, as well as some of the phase III transporter genes, such as MRP1 and Slco1b2. In addition, BHA activated distinct mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), as well as p38, suggesting that the MAPK pathways may play an important role in early signaling events leading to the regulation of gene expression including phase II drug metabolizing and some phase III drug transporter genes. This is the first study to demonstrate the in vivo pharmacokinetics of BHA, the in vivo activation of MAPK signaling proteins, as well as the in vivo induction of Phase II/III drug metabolizing enzymes/transporters in the mouse livers.

The Characteristics of Corrosion Resistance during Plasma Oxinitrocarburising for Carbon Steel (플라즈마 산질화처리 조건이 강의 내식성에 미치는 영향)

  • Lee, K.H.;Nam, K.S.;Lee, S.R.;Cho, H.S.;Shin, P.W.;Park, Y.M.
    • Journal of the Korean Society for Heat Treatment
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    • v.14 no.2
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    • pp.103-109
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    • 2001
  • Plasma nitrocarburising and post oxidation were performed on SM45C steel using a plasma nitriding unit. Nitrocarburising was carried out with various methane gas compositions with 4 torr gas pressure at $570^{\circ}C$ for 3 hours and post oxidation was carried out with 100% oxygen gas atmosphere with 4 torr at different temperatures for various times. It was found that the compound layer produced by plasma nitrocarburising consisted of predominantly ${\varepsilon}-Fe_{2-3}(N,C)$ and a small proportion of ${\gamma}-Fe_4(N,C)$. With increasing methane content in the gas mixture, ${\varepsilon}$ phase compound layer was favoured. In addition, when the methane content was further increased, cementite was observed in the compound layer. The very thin oxide layer on top of the compound layer was obtained by post oxidation. The formation of Oxide phase was initially started from the magnetite($Fe_3O_4$) and with increasing oxidation time, the oxide phase was increased. With increasing oxidation temperature, oxide phase was increased. However the oxide layer was split from the compound layer at high temperature. Corrosion resistance was slightly influenced by oxidation times and temperatures.

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