• Title/Summary/Keyword: Intrinsic Factor

Search Result 412, Processing Time 0.024 seconds

An Efficient Method for Production of Extracellular Human Tissue Factor in Escherichia coli (인간조직인자 세포외 부분의 효과적인 제조 방법)

  • Yoo, Hwan-Goo;Park, Yang-Jin;Lee, Woo-Yiel
    • Journal of Life Science
    • /
    • v.19 no.5
    • /
    • pp.561-565
    • /
    • 2009
  • Human Tissue factor is an essential enzyme activator that forms a catalytic complex with factor VII/ VIIa, and catalyzes both the extrinsic and intrinsic blood coagulation cascades. The extracellular domain of human tissue factor is responsible for association with the biological partner. The efficient procedures for preparing biologically active human tissue factor are essential for the preclinical and clinical studies with coaguligands. An expression vector in Escherichia coli has been constructed to direct the production of extracellular human tissue factor without a fusion protein or a $His_6$ at the N-terminus. The recombinant human tissue factor was expressed in large amounts as a non-native state in E. coli. The recombinant protein was simply renatured during the DEAE-sephacel chromatographic purification procedure. Our expression and purification system does not require a protease treatment or an additional chromatographic step to remove a fusion contaminant, which provides a very useful alternative to conventional expression systems for the production of human tissue factor.

Individual Characteristics Affecting User's Intention to Use Internet Shopping Mall (개인 특성이 인터넷 쇼핑몰 사용의도에 미치는 영향)

  • Suh, Chang-Kyo;Seong, Seok-Ju
    • Asia pacific journal of information systems
    • /
    • v.14 no.3
    • /
    • pp.1-22
    • /
    • 2004
  • Technology acceptance model(TAM) has been widely used to predict the end-user's acceptance of a new IT/IS. We used TAM as a theoretical foundation to explain user's intention to use an Internet shopping mall. The theoretical model is tested with the questionnaires from 308 users of an Internet shopping mall. Results show that several individual characteristics such as Internet skills and self-efficacy have a significant impact on user's perception of usefulness and ease of use. Results also show that both perceived enjoyment and perceived usefulness of Internet shopping mall strongly predict intention to use the Internet shopping mall. However, perceived ease of use has no direct influence on intention to use the Internet shopping mall. Personal innovativeness and Internet skills also have a positive effect on perceived enjoyment. Therefore, Internet shopping mall managers have to consider intrinsic motivational factor(enjoyment) as well as extrinsic motivational factor(usefulness). In addition, individual characteristics should be emphasized to form the positive beliefs about using the Internet shopping mall.

A Bayesian Outlier Detection in Random Effects Model (변량모형 자료에서의 베이지안 이상점검출)

  • 정윤식;이상진
    • The Korean Journal of Applied Statistics
    • /
    • v.13 no.1
    • /
    • pp.115-131
    • /
    • 2000
  • 이 논문에서는 평균-이동모형(mean-shift model)을 이상점을 위한 대립모형으로 사용하여 변량모형(random effect model)에서의 이상점 검출을 위한 베이즈인자(Bayes factor)를 제시한다. 그러나 가능한 사전 정보가 없어서 무정보사전분포(noninformative prior distribution)가 사용되어야만 할 때, 대부분의 무정보사전분포는 부적절분포(improper distribution)이기 때문에 베이즌 인자에는 사전분포로부터 나온 미지의 상수가 포함되어 잇다. 이 문제를 해결하기 위해 이 논문에서는 Berger와 Pericchi (1996)가 제시한 내재베이즈인자(the intrinsic Bayes factor;IBF)를 사용한다. 또한 이 베이즈인자를 계산상 어려움을 해결하기 위해 Verdinellidh Wasserman(1995)의 일반화 세비디지키 밀도비를 이용하여 수정하고 이것을 이용하여 이상점을 검출하는 방법을 제시한다. 마지막으로 인위적으로 이상점을 포함하고 있는 데이터를 만들고 제시된 방법으로 가상실험을 하고 또한 실제 데이터에서 제시한 방법으로 이상점을 찾아보았다.

  • PDF

Bayesian Model Selection for Nonlinear Regression under Noninformative Prior

  • Na, Jonghwa;Kim, Jeongsuk
    • Communications for Statistical Applications and Methods
    • /
    • v.10 no.3
    • /
    • pp.719-729
    • /
    • 2003
  • We propose a Bayesian model selection procedure for nonlinear regression models under noninformative prior. For informative prior, Na and Kim (2002) suggested the Bayesian model selection procedure through MCMC techniques. We extend this method to the case of noninformative prior. The difficulty with the use of noninformative prior is that it is typically improper and hence is defined only up to arbitrary constant. The methods, such as Intrinsic Bayes Factor(IBF) and Fractional Bayes Factor(FBF), are used as a resolution to the problem. We showed the detailed model selection procedure through the specific real data set.

Prediction of Concrete Pumping Using Various Rheological Models

  • Choi, Myoung Sung;Kim, Young Jin;Kim, Jin Keun
    • International Journal of Concrete Structures and Materials
    • /
    • v.8 no.4
    • /
    • pp.269-278
    • /
    • 2014
  • When concrete is being transported through a pipe, the lubrication layer is formed at the interface between concrete and the pipe wall and is the major factor facilitating concrete pumping. A possible mechanism that illustrates to the formation of the layer is the shear-induced particle migration and determining the rheological parameters is a paramount factor to simulate the concrete flow in pipe. In this study, numerical simulations considering various rheological models in the shear-induced particle migration were conducted and compared with 170 m full-scale pumping tests. It was found that the multimodal viscosity model representing concrete as a three-phase suspension consisting of cement paste, sand and gravel can accurately simulate the lubrication layer. Moreover, considering the particle shape effects of concrete constituents with increased intrinsic viscosity can more exactly predict the pipe flow of pumped concrete.

A Study of Anticoagulation Activity from Perillae Folium Extract (자소엽(紫蘇葉) 추출물의 항응혈(抗凝血) 활성에 관한 연구(硏究))

  • Jeoung, Gyong-Hee;Han, Sin-Hee;Kil, Gi-Jung
    • The Korea Journal of Herbology
    • /
    • v.23 no.4
    • /
    • pp.191-196
    • /
    • 2008
  • Objectives: This research was investigated to find out the effect of the anticoagulant Perillae folium extract. Methods: To examine an active effect of anticoagulation in Perillae folium extract, the study measured Prothrombin time(PT) and activated partial thromboplastin time(APTT) of human plasma in vitro and measured bleeding time and arterio-venous shunt model in rats in vivo. Results: Bleeding time of Perillae folium extract in vivo had a significant increase 1.6 times and thrombus weight of Perillae folium extract had a significant reduction of thrombus weight as 68%. Perillae folium extract had an effect of anticoagulation by operating on extrinsic pathway factor II, V, VII, X and intrinsic pathway factor VIII, IX, X, VI, VII in the coagulation system. Conclusions: Considering the above mentioned results, it is judged that a Perillae folium extract has a control effect of thrombus creation.

  • PDF

A Novel Anticoagulant Protein from Scapharca broughtonii

  • Jung, Won-Kyo;Je, Jae-Young;Kim, Hee-Ju;Kim, Se-Kwon
    • BMB Reports
    • /
    • v.35 no.2
    • /
    • pp.199-205
    • /
    • 2002
  • An anticoagulant protein was purified from the edible portion of a blood ark shell, Scapharca broughtonii, by ammonium sulfate precipitation and column chromatography on DEAE-Sephadex A-50, Sephadex G-75, DEAE-Sephacel, and Biogel P-l00. In vitro assays with human plasma, the anticoagulant from 'S. broughtonii, prolonged the activated partial thromboplastin time (APTT) and inhibited the factor LX in the intrinsic pathway of the blood coagulation cascade. But, the fibrin plate assay did not show that the anticoagulant is a fibrinolytic protease. The molecular mass of the purified S. broughtonii anticoagulant was measured to be about 26.0kDa by gel filtration on a Sephadex G-75 column and SDS-PAGE under denaturing conditions. The optimum activity in the APTT assay was exhibited at pH 7.0-7.5 and $40-45^{\circ}C$ in the presence of $Ca^{2+}$.

A Comparison of improved EFG method with the singular expression for crack tip (균열선단의 특이성을 반영한 개선된 EFG 해석기법들의 비교)

  • 이상호;윤영철
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2002.04a
    • /
    • pp.69-76
    • /
    • 2002
  • In this paper, several improved Element-Free Galerkin (EFG) methods containing singular expression in their approximation functions are compared one another through a patch test with near-tip field. Intrinsic enrichments that expand the basis function partially and fully with known near-tip displacement field and a local enrichment using auxiliary supports based on the partition of unity concept are examined by evaluating a relative stress norm error and the stress intensity factor. Some numerical examinations graphically show that how the size of compact support, dilation parameter and the diffraction parameter can affect the accuracy of the improved EFG methods in the error and the stress intensity factor.

  • PDF

AN EFFICIENT MONTE-CARLO ALGORITHM FOR DUST-SCATTERING STUDY (성간먼지 산란 연구를 위한 효율적인 몬테카를로 알고리즘)

  • Seon, Kwang-Il
    • Publications of The Korean Astronomical Society
    • /
    • v.25 no.4
    • /
    • pp.177-186
    • /
    • 2010
  • We developed an efficient Monte-Carlo algorithm to solve dust-scattering radiative transfer problems for continuum radiation. The method calculates the scattered intensities for various anisotropic factors ($g_i$) all at once, while actual photon packets are tracked following a scattering phase function given by a single anisotropic factor ($g_0$). The algorithm was tested by applying the method to a dust cloud embedding a star at the cloud center and found to provide accurate results within the statistical fluctuation that is intrinsic in Monte-Carlo simulations. It was found that adopting $g_0$ = 0.4 - 0.5 in the algorithm is most efficient. The method would be efficient in estimating the anisotropic factor of the interstellar dust by comparing the observed data with radiative transfer models.

Protein Interaction Mapping of Translational Regulators Affecting Expression of the Critical Stem Cell Factor Nos

  • Malik, Sumira;Jang, Wijeong;Kim, Changsoo
    • Development and Reproduction
    • /
    • v.21 no.4
    • /
    • pp.449-456
    • /
    • 2017
  • The germline stem cells of the Drosophila ovary continuously produce eggs throughout the life-span. Intricate regulation of stemness and differentiation is critical to this continuous production. The translational regulator Nos is an intrinsic factor that is required for maintenance of stemness in germline stem cells. Nos expression is reduced in differentiating cells at the post-transcriptional level by diverse translational regulators. However, molecular mechanisms underlying Nos repression are not completely understood. Through three distinct protein-protein interaction experiments, we identified specific molecular interactions between translational regulators involved in Nos repression. Our findings suggest a model in which protein complexes assemble on the 3' untranslated region of Nos mRNA in order to regulate Nos expression at the post-transcriptional level.