• Title/Summary/Keyword: $R2^*$

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Overproduction of Bacterial Trypsin in Streptomyces - Optimization for Streptomyces griseus Trypsin Production by Recombinant Streptomyces (미생물을 이용한 트립신 과대 생산 연구 - Streptomyces용 숙주-벡터계를 이용한 트립신 유전자의 대량발현 최적화 -)

  • Kim, Jong-Hee;Hong, Soon-Kwang
    • Microbiology and Biotechnology Letters
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    • v.36 no.1
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    • pp.28-33
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    • 2008
  • The expression vector (pWHM3-TR1R2) for sprT gene encoding Streptomyces griseus trypsin (SGT) followed by two regulatory genes, sgtR1 and sgtR2, was introduced into Streptomyces lividans TK24 and Streptomyces griseus IFO 13350. Various media with different compositions were used to maximize the productivity of SGT in the recombinant trains. he SGT productivity was best when the transformant of S. lividans TK24 was cultivated in R2YE medium (0.74 unit/mL) at 5 days of cultivation. C5/L (0.66 unit/mL) medium also gave a good productivity, but Livid (0.08 unit/mL) and NDSK (0.06 unit/mL) yielded poor productivities. S. griseus IFO 13350/pWHM3-TR1R2 produced SGT by 1.518 unit/mL (C5/L), 1.284unit/mL (R2YE),0.932 unit/mL (NDSK), and 0.295 unit/mL (Livid) at 7 days of cultivation, which was much higher than those from S. lividans TK24/TR1R2. The SGT protein was purified from the culture broth of S. griseus IFO 13350/pWHM3-TR1R2 in C5/L to homogeneity via ammonium sulfate fractionation, and CM-sepharose and SP-sepharose column chromatographies. The specific activity of purified SGT was 69,252 unit/mg, and the final purification fold and recovery yield were 6.5 and 1.4%, respectively.

EVERY DEFINABLE Cr MANIFOLD IS AFFINE

  • KAWAKAMI, TOMOHIRO
    • Bulletin of the Korean Mathematical Society
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    • v.42 no.1
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    • pp.165-167
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    • 2005
  • Let M = (R, +, $\cdot$, <, ... ) be an o-minimal expansion of the standard structure R = (R, +, $\cdot$, >) of the field of real numbers. We prove that if 2 $\le$ r < $\infty$, then every n-dimensional definable $C^r$ manifold is definably $C^r$ imbeddable into $R^{2n+l}$. Moreover we prove that if 1 < s < r < $\infty$, then every definable $C^s$ manifold admits a unique definable $C^r$ manifold structure up to definable $C^r$ diffeomorphism.

A STUDY ON SUBSTRUCTURES OF R-GROUPS

  • Cho, Yong-Uk
    • East Asian mathematical journal
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    • v.25 no.2
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    • pp.171-177
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    • 2009
  • Throughout this paper, we denote that R is a near-ring and G an R-group. We initiate a study of R-substructures of G, monogenic R-groups, faithful R-groups and faithful D.G. representations of near-rings. Next, we investigate some properties of monogenic R-groups, faithful monogenic R-groups and a generalization of annihilator concepts in R-groups.

Novel Cationic Group 4 Metal Alkyl Complexes for Olefin Polymerizations (올레핀중합용 첨단 양이온형 제4족 유기금속 착물)

  • Kim, Il
    • Polymer Science and Technology
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    • v.5 no.3
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    • pp.236-253
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    • 1994
  • 양이온형 $d^0\;Cp_2M(R)(L)^+$ 착물과 무염기 $Cp_2M(R)^+$ 착물은 $Cp_2M(R)_2$화합물로부터 쉽게 합성할 수 있다. 이들 친전자성 착물에서는 여러가지 리간드 교환반응, 삽입반응, ${\beta}$-H 제거반응 및 ${\sigma}$-결합 복분해반응이 일어날 수 있다. 일반적으로 $Cp2M(R)(L)^+$ 착물은 불포화도와 전하가 크기때문에 중성의 $Cp_2M(R)(X)$$Cp_2M(R)_2$보다 반응성이 크며 $d^0\;{Cp_2}^*M(R)^+$ (M=제 3족과 란탄계) 착물과 여러가지 반응에서 유사한 거동을 보인다. $Cp_2MX_2$를 기초로하여 합성된 Ziegler-Natta 촉매에 의한 올레핀 중합에서 활성점이 $Cp_2M(R)^+$ 양이온이라는 여러가지 직접적인 증거가 발표되었다. 분리가능한 $Cp_2M(R)(L)^+$ 착물은 올레핀중합에서 높은 활성을 보이며, 유기합성의 관점에서 흥미있는 C-C 재조합반응과 같은 다른 여러가지 반응이 일어날 수 있는 기회를 제공한다.

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Preparation of a 20(R)-Ginsenoside $Rh_2$ and the 20(S) Epimer from Protopanaxadiol Saponins of Panax ginseng C.A. Meyer (인삼의 Protopanaxadiol계 사포닌으로부터 20(R)-Ginsenoside $Rh_2$ 및 20(S) 이성체의 제조)

  • 김신일;백남인;김동선;이유희;강규상;박종대
    • YAKHAK HOEJI
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    • v.35 no.5
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    • pp.432-437
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    • 1991
  • A mixture of 20(R)- and 20(S)-ginsenoside Rg$_{3}$ was obtained under mild acidic hydrolysis from protopanaxadiol saponins, ginsenosides Rb$_{1}$, Rb$_{2}$, Rc and Rd. The product was acetylated to give the peracetates, which were further converted into 20(R)-ginsenoside Rg$_{3}$, 20(S)-ginsenoside Rg$_{3}$, 20(R)-ginsenoside Rh$_{2}$ and 20(S)-ginsenoside Rh$_{2}$ by the direct alkaline treatment depending upon two kinds of temperature conditions respectively. The structure and physicochemical properties of a prosapogenin, 20(R)-ginsenoside Rh$_{2}$, were investigated.

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C2DPCA & R2DLDA for Face Recognition (얼굴 인식 시스템을 위한 C2DPCA & R2DLDA)

  • Yun, Tae-Sung;Song, Young-Jun;Kim, Dong-Woo;Ahn, Jae-Hyeong
    • The Journal of the Korea Contents Association
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    • v.10 no.8
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    • pp.18-25
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    • 2010
  • The study has proposed a method that simultaneously takes advantage of each projection matrix acquired by using column-directional two-dimensional PCA(C2DPCA) and row-directional two-dimensional LDA(R2DLDA). The proposed method can acquire a great secure recognition rate, with no relation to the number of training images, with acquired low-dimensional feature matrixes including both the horizontal and the vertical features of a face. Besides, in the alternate experiment of PCA and LDA to row-direction and column-direction respectively(C2DPCA & R2DLDA, C2DLDA & R2DPCA), we could make sure the system of 2 dimensional LDA with row-directional feature(C2DPCA & R2DLDA) obtain higher recognition rate with low dimension than opposite case. As a result of experimenting that, the proposed method has showed a greater recognition rate of 99.4% than the existing methods such as 2DPCA and 2DLDA, etc. Also, it was proved that its recognition processing is over three times as fast as that of 2DPCA or 2DLDA.

Nitric Oxide and Hydrogen Peroxide Production are Involved in Systemic Drought Tolerance Induced by 2R,3R-Butanediol in Arabidopsis thaliana

  • Cho, Song-Mi;Kim, Yong Hwan;Anderson, Anne J.;Kim, Young Cheol
    • The Plant Pathology Journal
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    • v.29 no.4
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    • pp.427-434
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    • 2013
  • 2R,3R-Butanediol, a volatile compound produced by certain rhizobacteria, is involved in induced drought tolerance in Arabidopsis thaliana through mechanisms involving stomatal closure. In this study, we examined the involvement of nitric oxide and hydrogen peroxide in induced drought tolerance, because these are signaling agents in drought stress responses mediated by abscisic acid (ABA). Fluorescence-based assays showed that systemic nitric oxide and hydrogen peroxide production was induced by 2R,3R-butanediol and correlated with expression of genes encoding nitrate reductase and nitric oxide synthase. Co-treatment of 2R,3R-butanediol with an inhibitor of nitrate reductase or an inhibitor of nitric oxide synthase lowered nitric oxide production and lessened induced drought tolerance. Increases in hydrogen peroxide were negated by co-treatment of 2R,3R-butanediol with inhibitors of NADPH oxidase, or peroxidase. These findings support the volatile 2R,3R-butanediol synthesized by certain rhizobacteria is an active player in induction of drought tolerance through mechanisms involving nitric oxide and hydrogen peroxide production.

Co-expression of a novel ankyrin-containing protein, rSIAP, can modulate gating kinetics of large-conductance calcium-activated potassium channel from rat brain.

  • Lim, Hyun-Ho;Park, Chul-Seung
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.45-45
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    • 2003
  • We isolated a novel ankyrin-repeat containing protein, rSIAP (rSlo Interacting Ankyrin-repeat Protein), as an interacting protein to the cytosolic domain of the alpha-subunit of rat large-conductance Ca$\^$2+/-activated K$\^$+/ channel (rSlo) by yeast two-hybrid screening. Affinity pull-down assay showed the direct and specific interaction between rSIAP and rSlo domain. The channel-binding proteins can be classified into several categories according to their functional effects on the channel proteins, i.e. signaling adaptors, scaffolding net, molecular tuners, molecular chaperones, etc. To obtain initial clues on its functional roles, we investigated the cellular localization of rSIAP using immunofluorescent staining. The results showed the possible co-localization of rSlo and rSIAP protein near the plasma membrane, when co-expressed in CHO cells. We then investigated the functional effects of rSIAP on the rSlo channel using electrophysiological means. The co-expression of rSIAP accelerated the activation of rSlo channel. These effects were initiated at the micromolar [Ca$\^$2+/]$\_$i/ and gradually increased as [Ca$\^$2+/]$\_$i/ raised. Interestingly, rSIAP decreased the inactivation kinetics of rSlo channel at micromolar [Ca$\^$2+/]$\_$i/, while the rate was accelerated at sub-micromolar [Ca$\^$2+/]$\_$i/. These results suggest that rSIAP may modulate the activity of native BK$\_$Ca/ channel by altering its gating kinetics depending on [Ca$\^$2+/]$\_$i/. To localize critical regions involved in protein-protein interaction between rSlo and rSIAP, a series of sub-domain constructs were generated. We are currently investigating sub-domain interaction using both of yeast two-hybrid method and in vitro binding assay.

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Effect of Anti-inflammation on Oryeong-san Formulation for Mix Extract Tablet (오령산 정제 개발 및 항염증 효과)

  • Kim, Se Jin;Leem, Hyun Hee;Nam, Won Hee;Son, Su Mi;Choi, Hye Min;Kim, Myung Jin;Kim, Jung Ok;Lee, Hwa Dong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.6
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    • pp.348-354
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    • 2020
  • Oryeong-san (ORS) is a traditional Korean herbal medicine widely used for renal associated diseases, composed of five medicine herbs; Atractylodes japonica Koidzumi, Cinnamomum cassia Presl, Polyporus umbellatus Fries, Poria cocos Wolf and Alisma orientale Juzepzuk. We studied to improve the convenience of intake and portability by developing modernized dosage forms, and examined the effect on anti-inflammation of ORS. In order to develop the tablet formulation of ORS (ORS-F), the tablets were evaluated on the basis of physical characteristics include diameter, thickness, weight variation, hardness, friability and disintegration. To analyze the marker components of ORS-F, eight index markers from five herbal medicines were chosen. And the method using high performance liquid chromatography (HPLC) with diode-array detector method was established for the simultaneous analysis. The biological activities were examined the effect of ORS-F on pro-inflammation mediated by LPS-stimulation. The production of nitric oxide (NO) and cytokines were determined by reacting cultured medium with griess reagent and enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) were investigated by Western blot and RT-PCR. The anti-oxidant activities of OJS-F increased markedly, in a dose-dependent manner. and, The total phenolic compound and flavonoids contents of OJS-F were 10.20±0.09 ㎍/㎎ and 12.86±0.86 ㎍/㎎. OJS-F which is LPS has diminished in the LPS-induced release of inflammatory mediators (NO, iNOS, COX2 and PGE2) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) from the RAW264.7 macrophages. Therefore, the developed formulation for tablet of ORS-F provide efficiency and usability, and indicated effect of anti-inflammation.

Weakly np-Injective Rings and Weakly C2 Rings

  • Wei, Junchao;Che, Jianhua
    • Kyungpook Mathematical Journal
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    • v.51 no.1
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    • pp.93-108
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    • 2011
  • A ring R is called left weakly np- injective if for each non-nilpotent element a of R, there exists a positive integer n such that any left R- homomorphism from $Ra^n$ to R is right multiplication by an element of R. In this paper various properties of these rings are first developed, many extending known results such as every left or right module over a left weakly np- injective ring is divisible; R is left seft-injective if and only if R is left weakly np-injective and $_RR$ is weakly injective; R is strongly regular if and only if R is abelian left pp and left weakly np- injective. We next introduce the concepts of left weakly pp rings and left weakly C2 rings. In terms of these rings, we give some characterizations of (von Neumann) regular rings such as R is regular if and only if R is n- regular, left weakly pp and left weakly C2. Finally, the relations among left C2 rings, left weakly C2 rings and left GC2 rings are given.