• Title/Summary/Keyword: ${\alpha}_i$-properties

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Studies on the Production of Enzymes by Thermophilic Actinomycetes Part I. Isolation and Culture Conditions of Thermostable $\alpha$-Amylase Producing Actinomycete (고온성 방선균에 의한 효소생산에 관한 연구 제 1보 $\alpha$-Amylase생산균의 분이 및 효소생산 조건)

  • 양한철;금범환;최용진
    • Microbiology and Biotechnology Letters
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    • v.3 no.2
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    • pp.73-82
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    • 1975
  • In the course of studies on the production of thermostable amylases by thermophilic actinomycetes isolated from soils the investigation was carried out on the production of $\alpha$-amylase by G-1011 strain which had presented the most remarkable $\alpha$-amylase formation ability among 128 amylolytic isolates. The results were as follows : 1. Characteristics of G-1011 strain were compared with those descriptions of thermophilic actinomycetes given in Bergey's Manual. The strain was identical to these species of actinomycetes. The details of physiological properties of the strain luould he published in near future. 2. The optimum temperature for incubation of the cell growth of G-1011 strain and $\alpha$-amylase production by the strain was revealed to 5$0^{\circ}C$. 3. The effective medium for $\alpha$-amylase formation by the strain was consisted of 3.0%, soluble starch, 1.0%, peptone, 0.5%, yeast extract, 0.5%, NaCl, 0.1%, MgSO$_4$ㆍ7$H_2O$ 0.02%, $K_2$MPO$_4$and 0.002% FeSO$_4$ㆍ7$H_2O$. The pH of the medium was ajusted to 7.0 with phosphate buffer solution. 4. The maximum production of $\alpha$-amylase (3420 D. U/ml) by G-1011 strain resulted when it was grown for 16 hours with the culture of reciprocal shaking.

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Zanthoxylum rhetsa Stem Bark Extract Inhibits LPS-induced COX-2 and iNOS expression in RAW 264.7 Cells via the NF-${\kappa}B$ Inactivation

  • Thu, Nguyen Bich;Trung, Trinh Nam;Ha, Do Thi;Khoi, Nguyen Minh;Than, Nguyen Viet;Soulinho, Thipthaviphone;Nam, Nguyen Hai;Phuong, Tran Thi;Bae, Ki-Hwan
    • Natural Product Sciences
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    • v.16 no.4
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    • pp.265-270
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    • 2010
  • The methanol extract of Zanthoxylum rhetsa (MZRR) were evaluated for its ability to suppress the formation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. MZRR presented an inhibition of LPS-induced production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) in RAW 264.7 macrophages. Western blotting and RT-PCR analyses demonstrated that MZRR significantly inhibited the protein and mRNA expressions of iNOS and COX-2 in LPS-activated macrophages in a dose-dependent manner. LPS-induced COX-2, iNOS, and nuclear factor kappa beta (NF-${\kappa}B$) activity were also decreased in the presence of MZRR. The production of tumor necrosis factor-$\alpha$ (TNF-$\alpha$), the mRNA expression levels of pro-inflammatory cytokines, including TNF-$\alpha$ and IL-$1{\beta}$, were reduced after MZRR administration in a dose dependent-manner. These results suggest that the MZRR extract involved in the inhibition of iNOS and COX-2 via the NF-${\kappa}B$ pathway, revealing a partial molecular basis for anti-inflammatory properties of the MZRR extract.

Rest-frame optical spectroscopic properties of submillimeter galaxies

  • Shim, Hyunjin
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.74.3-74.3
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    • 2017
  • Considering the statistical redshift distribution of the known submillimeter galaxy (SMG) population, most of the significant optical emission lines such as [OII]${\lambda}3727$, $H{\beta}$, [OIII]${\lambda}5007$, and $H{\alpha}$ are redshifted into near-infrared. Using the 3D-HST grism data that provides low resolution NIR spectroscopy over the several deep fields covered by the JCMT large program S2CLS, I investigated the properties of the optical emission lines for submm galaxies which could be used as a proxy for future optical/NIR identification and follow up of the SMGs.

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The physicochemical properties and the antibacterial effects of Ag-treated activated carbon (은이 처리된 활성탄의 물리화학적 특성과 항균 특성)

  • 오원춘;김범수;오한준;김면건
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.3
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    • pp.339-346
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    • 1999
  • We studied th physicochemical properties and the antibacterial effects of the Ag-treated activated carbon. The adsorption isotherms for the series of Ag-impregnated activated carbons represented typical Type-I. The surface area of the impregnated carbon was in the range of $740~1110\;m^{2}/g$, while the surface area of starting materials was $1440\;m^{2}/g$. Using t-plot, ${\alpha}_{s}$}-plot as well as DR-plot, and the volume of micropore was obtained. From the SEM study, the highly developed porous structure and the homogeneous distribution of Ag on the surface of activated carbon were confirmed. Finally, antibacterial effects of Ag-treated carbon aginst E. coli was discussed.

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Sequential Estimation of variable width confidence interval for the mean

  • Kim, Sung Lai
    • Journal of the Chungcheong Mathematical Society
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    • v.14 no.2
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    • pp.47-54
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    • 2001
  • Let {Xn, n = 1,2,${\cdots}$} be i.i.d. random variables with the only unknown parameters mean ${\mu}$ and variance a ${\sigma}^2$. We consider a sequential confidence interval C1 for the mean with coverage probability 1-${\alpha}$ and expected length of confidence interval $E_{\theta}$(Length of CI)/${\mid}{\mu}{\mid}{\leq}k$ (k : constant) and give some asymptotic properties of the stopping time in various limiting situations.

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Escape of LyC and Lyα Photons from Simulated Turbulent Clouds

  • Kimm, Taysun;Blaizot, Jeremy;Garel, Thibault;Michel-Dansac, Leo;Katz, Harley;Rosdahl, Joakim;Verhamme, Anne;Haehnelt, Martin
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.73.2-73.2
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    • 2019
  • Understanding how ionizing radiation propagates from molecular clouds to the intergalactic space is the key to the study of reionization and the emergence of $Ly{\alpha}$ emission from galaxies. In this contribution, I will present our new efforts to better understand the escape of UV photons from turbulent clouds with different masses, star formation efficiencies, and spectral energy distributions using radiation-hydrodynamic simulations. I will also show predicted Lya profiles from turbulent clouds and discuss a few interesting differences identified when compared with the properties of the local green pea galaxies.

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Characterization of Barley ${\alpha}$-Amylase Chimeric Enzymes Expressed in Pichia pastoris (Pichia pastoris에서 발현된 보리 알파아밀라제 Chimera 효소들의 특성)

  • Kim, Tae-Jip;Yuk, Jeong-Bin;Choi, Seung-Ho;Jang, Myoung-Uoon;Svensson, Birte
    • Korean Journal of Microbiology
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    • v.46 no.1
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    • pp.80-85
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    • 2010
  • Two different ${\alpha}$-amylase isozymes (AMY1 and AMY2) found in barley malt share up to 80% of amino acid sequence identity with each other, but their enzymatic properties differ remarkably. AMY1 shows the highest activity at low concentration of calcium ion, while AMY2 is highly active at high calcium concentration. Meanwhile, BASI (Barley ${\alpha}$-Amylase/Subtilisin Inhibitor) protein specifically inhibits only AMY2. In the present study, three separate regions in AMY genes (I, II, and III) were assigned on the basis of restriction enzyme sites and four kinds of chimeric amylases have been obtained by swapping a part of regions with each other. Each chimera gene was successfully over-expressed in Pichia pastoris. From the results of enzymatic characterization, both AMY211 and AMY122 showed the mixed or intermediate type of calcium-dependent activity between AMY1 and 2. Meanwhile, only AMY221 chimera could be significantly inhibited by BASI protein. As a result, it can be proposed that some amino acid residues in the region I and II, except region III, of barley ${\alpha}$-amylases play very important roles in calcium-dependency and interaction with BASI.

Sintering and Electrical Properties According to Sb/Bi Ratio(I) : ZnO-Bi2O3-Sb2O3-Mn3O4-Cr2O3 Varistor (Sb/Bi비에 따른 5원계 바리스터의 소결거동 및 전기적 특성(I) : ZnO-Bi2O3-Sb2O3-Mn3O4-Cr2O3)

  • Hong, Youn-Woo;Lee, Young-Jin;Kim, Sei-Ki;Kim, Jin-Ho
    • Korean Journal of Materials Research
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    • v.22 no.12
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    • pp.675-681
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    • 2012
  • We aimed to examine the co-doping effects of 1/6 mol% $Mn_3O_4$ and 1/4 mol% $Cr_2O_3$ (Mn:Cr = 1:1) on the reaction, microstructure, and electrical properties, such as the bulk defects and grain boundary properties, of ZnO-$Bi_2O_3-Sb_2O_3$ (ZBS; Sb/Bi = 0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Mn,Cr-doped ZBS, ZBS(MnCr) varistors were controlled using the Sb/Bi ratio. Pyrochlore ($Zn_2Bi_3Sb_3O_{14}$), ${\alpha}$-spinel ($Zn_7Sb_2O_{12}$), and ${\delta}-Bi_2O_3$ (also ${\beta}-Bi_2O_3$ at Sb/Bi ${\leq}$ 1.0) were detected for all of the systems. Mn and Cr are involved in the development of each phase. Pyrochlore was decomposed and promoted densification at lower temperature on heating in Sb/Bi = 1.0 system by Mn rather than Cr doping. A more homogeneous microstructure was obtained in all systems affected by ${\alpha}$-spinel. In ZBS(MnCr), the varistor characteristics were improved dramatically (non-linear coefficient, ${\alpha}$ = 40~78), and seemed to form ${V_o}^{\cdot}$(0.33 eV) as a dominant defect. From impedance and modulus spectroscopy, the grain boundaries can be seen to have divided into two types, i.e. one is tentatively assigned to ZnO/$Bi_2O_3$ (Mn,Cr)/ZnO (0.64~1.1 eV) and the other is assigned to the ZnO/ZnO (1.0~1.3 eV) homojunction.

Anti-inflammatory Effect of Cheukbaekjurpihwan(CBJPH) (측백저피환(側柏樗皮丸)의 항염(抗炎) 및 면역반응(免疫反應)에 대한 실험적(實驗的) 연구(硏究))

  • Jo, Ok-Hyun;Choi, Chang-Min
    • The Journal of Korean Obstetrics and Gynecology
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    • v.21 no.2
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    • pp.152-165
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    • 2008
  • Purpose: It is the purpose of this study to investigate the anti-inflammatory effects and mechanism of cheukbaekjurpihwan(CBJPH) extract on LPS (lipopolysaccharide)-induced inflammatory mediators in murine peritoneal macrophages. Methods: To evaluate anti-inflammatory effects of CBJPH extract, the production of cytokines(TNF-${\alpha}$(tumor necrosis factor-alpha), IL(interleukin)-6, IL-12) and NO(nitric oxide) was measured in vitro and in vivo. And western blot analysis has been done to look into the mechanism. Results: CBJPH extract reduced LPS-induced NO, TNF-${\alpha}$ and IL-6, IL-12 productions in peritoneal macrophages. CBJPH extract inhibited the activation of JNK(c-Jun N-terminal kinase), but didn't inhibit the activation of MAPKs (mitogen-activated protein kinases) such as p38, ERK1/2(extracelluar signal-regulated kinase1/2) and the degradation of $I_{\kappa}B-{\alpha}$(inhibitory kappa B-alpha) in the LPS-stimulated peritoneal macrophages. CBJPH extract suppressed LPS-induced endotoxin shock and the productions of TNF-${\alpha}$, but not of IL-6, after an oral administration of CBJPH extract Conclusion: CBJPH extract suppressed the productions of LPS-induced NO and cytokines by preventing JNK from phosphorylation, which may provide a clinical basis for anti-inflammatory properties of CBJPH.

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