• Title/Summary/Keyword: gamma model

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Preparation of Thiol-chitosan Coated EPA-containing Liposome and Immune Response in Mouse Model of Atopic Dermatitis (티올키토산으로 피복된 EPA(Eicosapentaenoic acid) 함유 리포좀의 제조 및 아토피 감염 쥐에 대한 면역 특성)

  • Jung, Hyo-Yun;Kim, Jin;Lee, Yong-Wook;Lee, Ki-Young
    • KSBB Journal
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    • v.25 no.1
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    • pp.97-102
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    • 2010
  • The enhancement of immunity for atopic dermatitis with application of eicosapentaenoic acid (EPA)-loaded liposome was evaluated on NC/Nga mice. The EPA-loaded liposome was coated with thiol-chitosan. The liposomes were characterized with transmission electron microscopy (TEM), surface zeta potential & particle size analyzer (Zeta-PSA) and differential scanning calorimetry (DSC). The loading efficiency of EPA in the liposome was about 4.7%. The particle size of the EPA-Ioaded liposome was about 230 nm. The values of Immunoglobulin E (IgE), interleukin-4 (IL-4), and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) were reduced significantly with application of the EPA-loaded liposome. The interferon-$\gamma$ (IFN-$\gamma$) value was increased with the application effect. It is concluded that EPA loaded liposome have immunity advancing effects in mouse model of atopic dermatitis.

Application of Gamma Irradiation for the Reduction of Residual Nitrite and Nitrosamine in Meat Products

  • Ahn, Hyun-Joo;Kim, Jae-Hun;Lee, Ju-Woon;Jo, Cheorun;Byun, Myung-Woo
    • Food Science of Animal Resources
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    • v.24 no.4
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    • pp.367-372
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    • 2004
  • Nitrite, a curing agent of meat products, is precursors of carcinogenic N-nitrosamines during processing of meat products or under human stomach conditions as well as having its own toxicity. Some researches have been conducted to evaluate the effects of ionizing radiation on the reduction of residual nitrite and N-nitrosamines in an aqueous model system and cured meat products with different packaging methods during storage. These results showed that the gamma irradiation was effective in reducing the residual nitrite and N-nitrosamines in an aqueous model system as well as meat products. Especially, irradiation combined with vacuum or modified atmosphere packaging was more effective in nitrite and N-nitrosamines reduction than aerobic packaging during storage. The objective of this review is to introduce the irradiation technology for the application of reducing the residual nitrite and N-nitrosamine contents in meat products.

Estimation of Storage Life for Propellant Bag by Using Gamma Process Model (감마과정 모델에 의한 장약포의 저장수명 예측)

  • Park, Sungho;Kim, Jaehoon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.3
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    • pp.17-25
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    • 2014
  • The purpose of this paper is to present a method to estimate the storage life of propellant bag for degradation of breaking load with storage time by using gamma process model. The nitrogen compound generated by natural decomposition of propellants degrades the breaking load of propellant bag with time. The statistical distributions of condition and lifetime with time were shown from the results of accelerated life test of propellant bag cloth at $80^{\circ}C$. It was found that the use of median for life was highly appropriate and the $B_1$ or $B_5$ life should be selectively applied to the quality assurance policy.

Removal of cobalt ions from aqueous solution using chitosan grafted with maleic acid by gamma radiation

  • Zhuang, Shuting;Yin, Yanan;Wang, Jianlong
    • Nuclear Engineering and Technology
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    • v.50 no.1
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    • pp.211-215
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    • 2018
  • Chitosan was modified by gamma radiation-induced grafting with maleic acid and then used for the removal of cobalt ions from aqueous solutions. Chitosan-g-maleic acid was characterized by Fourier Transform infrared spectroscopy (FT-IR). The effect of the dose (1-5 kGy) and monomer concentration (0.3-1.3%, m/v) on the grafting ratio was examined. The adsorption kinetics and isotherms were also investigated. The results showed that the optimal dose for grafting was 2 kGy. When monomer concentration was within the range of 0.3-1.3% (m/v), the grafting ratio increased almost linearly. For the adsorption of cobalt ions by chitosan-g-maleic acid beads, the pseudo second-order kinetic model ($R^2=0.99$) and Temkin isotherm model ($R^2=0.96$) were able to fit the experimental data reasonably well. The equilibrium adsorption capacity of cobalt ions increased from 2.00 mg/g to 2.78 mg/g after chitosan modification.

Basic characterization of uranium by high-resolution gamma spectroscopy

  • Choi, Hee-Dong;Kim, Junhyuck
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.929-936
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    • 2018
  • A basic characterization of uranium samples was performed using gamma- and X-ray spectroscopy. The studied uranium samples were eight types of certified reference materials with $^{235}U$ enrichments in the range of 1-97%, and the measurements were performed over 24 h using a high-resolution and high-purity planar germanium detector. A general peak analysis of the spectrum and the $XK_{\alpha}$ region of the uranium spectra was carried out by using HyperGam and HyperGam-U, respectively. The standard reference sources were used to calibrate the spectroscopy system. To obtain the absolute detection efficiency, an effective solid angle code, EXVol, was run for each sample. Hence, the peak activities and isotopic activities were determined, and then, the total U content and $^{234}U$, $^{235}U$, and $^{238}U$ isotopic contents were determined and compared with those of the certified reference values. A new method to determine the model age based on the ratio of the activities of $^{223}Ra$ and $^{235}U$ in the sample was studied, and the model age was compared with the known true age. In summary, the present study developed a method for basic characterization of uranium samples by nondestructive gamma-ray spectrometry in 24 h and to obtain information on the sample age.

Intracellular Flux Prediction of Recombinant Escherichia coli Producing Gamma-Aminobutyric Acid

  • Sung Han Bae;Myung Sub Sim;Ki Jun Jeong;Dan He;Inchan Kwon;Tae Wan Kim;Hyun Uk Kim;Jong-il Choi
    • Journal of Microbiology and Biotechnology
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    • v.34 no.4
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    • pp.978-984
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    • 2024
  • Genome-scale metabolic model (GEM) can be used to simulate cellular metabolic phenotypes under various environmental or genetic conditions. This study utilized the GEM to observe the internal metabolic fluxes of recombinant Escherichia coli producing gamma-aminobutyric acid (GABA). Recombinant E. coli was cultivated in a fermenter under three conditions: pH 7, pH 5, and additional succinic acids. External fluxes were calculated from cultivation results, and internal fluxes were calculated through flux optimization. Based on the internal flux analysis, glycolysis and pentose phosphate pathways were repressed under cultivation at pH 5, even though glutamate dehydrogenase increased GABA production. Notably, this repression was halted by adding succinic acid. Furthermore, proper sucA repression is a promising target for developing strains more capable of producing GABA.

New Dispersion Function in the Rank Regression

  • Choi, Young-Hun
    • Communications for Statistical Applications and Methods
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    • v.9 no.1
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    • pp.101-113
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    • 2002
  • In this paper we introduce a new score generating (unction for the rank regression in the linear regression model. The score function compares the $\gamma$'th and s\`th power of the tail probabilities of the underlying probability distribution. We show that the rank estimate asymptotically converges to a multivariate normal. further we derive the asymptotic Pitman relative efficiencies and the most efficient values of $\gamma$ and s under the symmetric distribution such as uniform, normal, cauchy and double exponential distributions and the asymmetric distribution such as exponential and lognormal distributions respectively.

T Lymphocyte Development and Activation in Humanized Mouse Model

  • Lee, Ji Yoon;Han, A-Reum;Lee, Dong Ryul
    • Development and Reproduction
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    • v.23 no.2
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    • pp.79-92
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    • 2019
  • Humanized mice, containing engrafted human cells and tissues, are emerging as an important in vivo platform for studying human diseases. Since the development of Nod scid gamma (NSG) mice bearing mutations in the IL-2 receptor gamma chain, many investigators have used NSG mice engrafted with human hematopoietic stem cells (HSCs) to generate functional human immune systems in vivo, results in high efficacy of human cell engraftment. The development of NSG mice has allowed significant advances to be made in studies on several human diseases, including cancer and graft-versus-host-disease (GVHD), and in regenerative medicine. Based on the human HSC transplantation, organ transplantation including thymus and liver in the renal capsule has been performed. Also, immune reconstruction of cells, of the lymphoid as well as myeloid lineages, has been partly accomplished. However, crosstalk between pluripotent stem cell derived therapeutic cells with human leukocyte antigen (HLA) mis/matched types and immune CD3 T cells have not been fully addressed. To overcome this hurdle, human major histocompatibility complex (MHC) molecules, not mouse MHC molecules, are required to generate functional T cells in a humanized mouse model. Here, we briefly summarize characteristics of the humanized mouse model, focusing on development of CD3 T cells with MHC molecules. We also highlight the necessity of the humanized mouse model for the treatment of various human diseases.

A Structural Equation Model of Factors Influencing Posttraumatic Growth of Earthquake Victims (지진 피해자의 외상 후 성장에 영향을 미치는 요인들 간의 구조모형)

  • Kwak, Minyeong
    • Research in Community and Public Health Nursing
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    • v.30 no.3
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    • pp.345-356
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    • 2019
  • Purpose: The purpose of this study is to construct and test a structural equation model of posttraumatic growth (PTG) of earthquake victims based on Tedeschi and Calhoun's model (2004). Methods: Data were collected from 195 earthquake victims living in K. City. The exogenous variables include distress perception, resilience, and social support, and the endogenous variables include intrusive rumination, deliberate rumination, and posttraumatic growth. For data analysis, descriptive statistics, factor analysis, and structural equation modeling were performed. Results: The modified model showed a good fitness to the data. Moreover, 6 of the 9 paths of the final model were statistically significant, which include PTG affected by deliberate rumination (${\beta}=.58$, p<.001), resilience (${\gamma}=.18$, p=.001), and distress perception (${\gamma}=.20$, p=.002). These predictors explain 51.8% of variance in posttraumatic growth. Conclusion: Based on the results of this study, it is necessary to develop and disseminate preventive intervention programs to increase the resilience of earthquake-prone communities. In addition, after exposure to a community-scale traumatic event such as earthquake, we should provide social supports to alleviate distress perception and transition from intrusive rumination to deliberate rumination so that we can seek new meaning from the earthquake and facilitate posttraumatic growth.

Proposal of Parameter Range that Offered Optimal Performance in the Coastal Morphodynamic Model (XBeach) Through GLUE

  • Bae, Hyunwoo;Do, Kideok;Kim, Inho;Chang, Sungyeol
    • Journal of Ocean Engineering and Technology
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    • v.36 no.4
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    • pp.251-269
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    • 2022
  • The process-based XBeach model has numerous empirical parameters because of insufficient understanding of hydrodynamics and sediment transport on the nearshore; hence, it is necessary to calibrate parameters to apply to various study areas and wave conditions. Therefore, the calibration process of parameters is essential for the improvement of model performance. Generally, the trial-and-error method is widely used; however, this method is passive and limited to various and comprehensive parameter ranges. In this study, the Generalized Likelihood Uncertainty Estimation (GLUE) method was used to estimate the optimal range of three parameters (gamma, facua, and gamma2) using morphological field data collected in Maengbang beach during the four typhoons that struck from September to October 2019. The model performance and optimal range of empirical parameters were evaluated using Brier Skill Score (BSS) along with the baseline profiles, sensitivity, and likelihood density analysis of BSS in the GLUE tools. Accordingly, the optimal parameter combinations were derived when facua was less than 0.15 and simulated well the shifting shape, from crescentic sand bar to alongshore uniform sand bars in the surf zone of Maengbang beach after storm impact. However, the erosion and accretion patterns nearby in the surf zone and shoreline remain challenges in the XBeach model.