• 제목/요약/키워드: ${\alpha}_i$-properties

검색결과 386건 처리시간 0.026초

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

  • 양한철;금범환;최용진
    • 한국미생물·생명공학회지
    • /
    • 제3권2호
    • /
    • pp.73-82
    • /
    • 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.

  • PDF

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
    • /
    • 제16권4호
    • /
    • pp.265-270
    • /
    • 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
    • 천문학회보
    • /
    • 제42권2호
    • /
    • pp.74.3-74.3
    • /
    • 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.

  • PDF

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

  • 오원춘;김범수;오한준;김면건
    • 한국결정성장학회지
    • /
    • 제9권3호
    • /
    • pp.339-346
    • /
    • 1999
  • 본 연구에서는 은이 처리된 활성탄에 물리화학적 특성과 항균성에 대하여 연구하였다. 은이 처리된 활성탄에 대한 흡착등온곡선은 대표적인 Type-I 형태를 나타내었다. 출발물질의 비표면적은 $1440\;m^{2}/g$를 나타낸 반면에 금속이 처리된 활성탄은 $740~1110\;m^{2}/g$에 범위에 분포하였다. 또한 이들 시료에 대하여 t-plot, ${\alpha}_{s}$}-plot와 DR-plot로부터 미세 동공부피를 구하였다. SEM 연구로 부터 활성탄의 표면에 은이 균일한 분포와 상당히 균일한 동공 분포를 확인하였다. 그리고 최종적으로 은이 처리된 활성탄에 대하여 E. coli에 대한 항균효과에 대하여 토론하였다.

  • PDF

Sequential Estimation of variable width confidence interval for the mean

  • Kim, Sung Lai
    • 충청수학회지
    • /
    • 제14권2호
    • /
    • pp.47-54
    • /
    • 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.

  • PDF

Escape of LyC and Lyα Photons from Simulated Turbulent Clouds

  • 김태선
    • 천문학회보
    • /
    • 제44권1호
    • /
    • pp.73.2-73.2
    • /
    • 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.

  • PDF

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

  • 김태집;육정빈;최승호;장명운
    • 미생물학회지
    • /
    • 제46권1호
    • /
    • pp.80-85
    • /
    • 2010
  • 보리 맥아로부터 발견된 서로 다른 알파아밀라제 동질효소(AMY1, AMY2)는 80%에 달하는 높은 아미노산 서열의 상동성을 보이지만, 두 효소의 특성은 서로 달라 AMY1 효소는 낮은 농도의 칼슘 조건에서 최대 활성을 보이는 반면, AMY2 효소는 높은 칼슘이온 농도에서 높은 활성을 나타낸다. 또한 BASI (Barley ${\alpha}$-Amylase/Subtilisin Inhibitor) 단백질은 AMY2 효소만을 특이적으로 저해한다. 따라서 본 연구에서는 AMY1과 AMY2 효소의 유전자를 I, II, III의 세 부위로 나눈 후, 제한효소 처리에 의해 일부 부위를 상호 치환한 4종의 chimera 효소를 추가로 제조하고, Pichia pastoris 균주에서 대량 발현하였다. 이들 효소의 특성을 비교한 결과, 제 I 부위만이 상호치환된 AMY211 및 AMY122 효소의 경우, AMY1과 AMY2의 중간적 칼슘 의존성을 나타내었으며, BASI에 의한 저해효과는 AMY2의 제 I, II 부위를 포함하는 AMY221 효소에서만 관찰되었다. 따라서 보리 아밀라제의 제 I 부위 및 제 II 부위에 존재하는 아미노산 잔기들이 칼슘 의존성 및 BASI와의 결합에 중요한 역할을 담당하는 반면 제 III 부위는 이들 효소의 활성 차이에 영향을 미치지 않음을 확인하였다.

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

  • 홍연우;이영진;김세기;김진호
    • 한국재료학회지
    • /
    • 제22권12호
    • /
    • pp.675-681
    • /
    • 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.

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) (Anti-inflammatory Effect of Cheukbaekjurpihwan(CBJPH))

  • 조옥현;최창민
    • 대한한방부인과학회지
    • /
    • 제21권2호
    • /
    • pp.152-165
    • /
    • 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.

  • PDF