• Title/Summary/Keyword: co-culture model

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Investigating the Effects of Relationship Quality on Organizational Commitment and Prosocial Behavior in Hotel Food & Beverage Division

  • Lee, Yong-Ki;Kwon, Yong-Ju;Lee, Kyung-Ah
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.3
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    • pp.109-132
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    • 2007
  • The present study examines the relationship among relationship quality, organizational commitment, and prosocial behavior. In this study, relationship quality is defined as relationship quality between manager and employee (RQME) and relationship quality between organization and employee (RQOE). The authors also investigate the mediating roles of RQOE and organizational commitment in the conceptual research model. Findings indicate that RQME has a positive and direct effect on RQOE, organizational commitment, and prosocial behavior. The results also show that both RQOE and organizational commitment have a mediating role in the relationship between RQME and prosocial behavior of employees. Finally, the authors found that RQOE influences prosocial behavior through organizational commitment.

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Genomic and Transgenic Approaches to Modified Plants: Disease Resistance in the Brassica as a Model System.

  • Ekuere, Usukuma;Good, Allen G.;Mayerhofer, Reinhold
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.4
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    • pp.317-323
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    • 2000
  • Molecular genetic techniques can now be applied to the development of advanced plant genotypes, either through genetic transformation or genomic approaches which allow researchers to transfer specific traits using molecular markers. In this paper, we discuss the use of these techniques towards understanding the genetics of blackleg resistance in Brassica. In a comparative mapping study between Arabidopsis thaliana and Brassica napus, 6 R-ESTs, 7 B. napus RFLP markers and a B. napus EST were located in a collinear region of N7 (B. napus) and chromosome 1 (A. thaliana). One of the A. thaliana R-ESTs and 4 of the B. napus RFLPs co-segregated and mapped to the LmRl locus for blackleg resistance. Introgression of blackleg resistance from wild relatives is also investigated with the possibility of accelerating the introgression process via marker assisted selection.

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Purification and reaction pattern of cephalexin synthesizing enzyme from Acetobacter turbidans

  • Kang, Sang-Moo;Kim, June-Hoe;Kim, Deog-Jung;Kim, Young-Jun
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.525.2-525
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    • 1986
  • Cephalexin synthesizing enzyme (${\alpha}$ amino acid ester hydrolase) was partially purified from the culture broth of Acetobacter turbidans ATCC9325 through ammonium sulfate fractionation, DEAE, CM, and Sephacryl S-200 gel filtration. The enzyme has optimum pH 6.0 and temperature, 40$^{\circ}C$ respectively. From the analysis of reaction mixtures by thin layer chromatographic and high performance liquid chromatographic techniques, it was confirmed this enzyme catalyzed simultaneously the following reactions : 1) Synthesis of cephalexin from D-${\alpha}$-phenylglycine methylester (PGM) and 7-amino 3-deacetoxy-cetoxycephalosporanic acid (7-ADCA) 2) Hydrolysis of cephalexin to form 7-ADCA and phenylglycine (PG) 3) Hydrolysis of PGM to form PG and methanol. Base on the above experimental observations, the reaction model of this enzyme was identical with that of the enzyme from Xanthomonas citri.

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Broadening Luxury through Sustainability: Cases from Craft-based Fashion

  • Na, Yuri
    • Fashion, Industry and Education
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    • v.16 no.2
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    • pp.40-51
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    • 2018
  • Sustainability is an important topic within a variety of design areas, including fashion. The 'fast fashion' behavior of consumers is one of the big challenges that sustainable living faces. For the fashion industry, sustainability can be seen as a regulating ethos for higher quality and longer-lasting products, which I argue as embodying an intersection between sustainability and luxury. This study establishes a conceptual model for 'sustainable luxury' that can be implemented as a guide in the fashion design industry and education field. This paper will focus particularly on craft-based fashion within the industry. Through conceptual analysis and case studies, I analyze sustainable luxury through the scope of Soper's (2007) 'alternative hedonism', linking hedonic and selfidentity values as a foundation for the acceptance of and continued drive toward more sustainable luxury products. Unlike other studies which only emphasize the ecological and environmental aspects of sustainability, viz. green/eco design, this study explores sustainability as balanced with its four dimensions: environmental, economic, social, and cultural. Case studies will exemplify this redefined notion of sustainable luxury.

Measuring Intracellular Mycobacterial Killing Using a Human Whole Blood Assay (인체 전혈 모델을 이용한 세포내 결핵균 살균력에 관한 연구)

  • Cheon, Seon-Hee;Song, Ho-Yeon;Lee, Eun-Hee;Oh, Hee-Jung;Kang, In-Sook;Cho, Ji-Yoon;Hong, Young-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.5
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    • pp.497-509
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    • 2002
  • Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.

Potential Probiotic Properties of Lactobacillus johnsonii IDCC 9203 Isolated from Infant Feces (유아 분변에서 분리한 Lactobacillus johnsonii IDCC 9203의 잠재적 프로바이오틱 특성)

  • Lee, Seung-Hun;Yang, Eun-Hee;Kwon, Hyuk-Sang;Kang, Jae-Hoon;Kang, Byung-Hwa
    • Microbiology and Biotechnology Letters
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    • v.36 no.2
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    • pp.121-127
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    • 2008
  • A strain IDCC 9203 isolated from infant feces was identified as Lactobacillus johnsonii on the basis of 16S rDNA sequence analysis. L. johnsonii IDCC 9203 was highly resistant to acid (MRS broth at pH 2.3) and bile (MRS broth with 0.3% oxgall). The antibacterial activities of L. johnsonii IDCC 9203 was examined against Salmonella typhimurium KCTC 2054. The growth of S. typhimurium KCTC 2054 was inhibited by the cell-free culture supernatant (at pH 4.0) of L. johnsonii IDCC 9203 as well as by the respective control (MRS broth at pH 4.0). Antimicrobial effect against S. typhimurium KCTC 2054 of L. johnsonii IDCC 9203 was probably due to the lactic acid. By an in vitro cell adhesion model, L. johnsonii IDCC 9203 preincubated or coincubated with Caco-2 cells reduced the adhesion of S. typhimurium KCTC 2054 to Caco-2 cells by 74% or 47.1%, respectively. Also in an in vivo model, L. johnsonii IDCC 9203 was colonized in mice intestines which were disrupted by ampicillin treatment. Its proliferation in the mice intestines reduced abnormal salmonella growth from $10^9CFU/g$ feces to $10^5CFU/g$ feces as an indigenous level. The results obtained in this study suggest that L. johnsonii IDCC 9203 may be a potential probiotic strain.

Prevention of ROS Production and MMP Dissipation by Fructus Schisandrae(FS) in a Hypoxic Model of Cultured Rat Hippocampal Neurons (오미자(五味子)(Fructus Schisandrae)가 흰쥐 해마신경세포의 저산소증 모델에서 세포사에 미치는 영향)

  • Ju, Dae-Hwan;Shin, Gil-Cho;Moon, Il-Soo
    • The Journal of Internal Korean Medicine
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    • v.29 no.4
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    • pp.835-845
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    • 2008
  • Objectives : The purpose of this study was to investigate the effect of FS for the modulation of ROS and MMP in a hypoxic model of cultured rat cortical cells. Methods : For the effect of FS on the viability, FS was added to culture media (neurobasal supplemented with B27) and cell viability was measured by LDH assay. To investigate the effects of FS on ROS generation and MMP preservation, cells grown in FS-containing media were given a hypoxic shock(2% $O_2/5%$ $CO_2$, $37^{\circ}C$, 3 hrs) on DIV 10, stained with $H_2DCF-DA$(10 nM) and JC-1, respectively, and observed by fluorescent microscope. Results : 1. FS has a protective effect of cortical cells in both normoxia and hypoxia. 2. FS reduced the generation of ROS and this reduction was especially significant at 3 days after hypoxia. 3. FS was effective for the maintenance of MMP in hypoxia, and this efficacy was especially significant at 3 days after hypoxia. Conclusions : Taken together, these results indicate that FS attenuates ROS generation and MMP dissipation, which eventually protects from neuronal cell death in hypoxia.

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Development of Inhibitors of $\beta$-Amyloid Plaque Formation

  • Kim, Dong-Jin
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2006.04a
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    • pp.123-135
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    • 2006
  • Alzheimer's disease (AD) is the most common form of dementia in the aging population and is clinically characterized by a progressive loss of cognitive abilities. Pathologically, it is defined by the appearance of senile plaques - extracellular insoluble, congophilic protein aggregates composed of amyloid $\beta$ (A$\beta$) and neurofibrillary tangles (NFTs) - inyracellular lesions consisting of paired helical filaments from hyperphosphorylated cytoskeletal tau protein as described by Alois Alzheimer a century ago. These hallmarks still serve as the major criteria for a definite diagnosis of the disease. Consequently, one of the key strategy for drug development in this disease area focuses on reducing the concentration of cerebral A$\beta$ plaque by using substances that inhibit A$\beta$ fibril formation. We focused on developing inhibitors by synthesizing several kinds of aromatic molecules. The synthetic compounds were initially screened to evaluate the effective compound by tioflavin T fluorescence assay. The selected effective compounds were tested cytotoxicity and protective effect from A$\beta$-induced neuronal toxicity by cell based MTT assay with HT22 hippocampal neurons. The BBB permeability on effectors was also tested in in vitro co-culture model(HUVEC/C6 cell line). The behavior test wea carried out in mutant APP/PS1 transgenic mouse model of Alzheimer's disease. And inhibition of A$\beta$ fibril formation by the effective compound was monitored with transmitted electron microscopic images.

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Suppression of Reactive Oxygen Species Production by Water-extracts of Coptidis Rhizoma Enhances Neuronal Survival in a Hypoxic Model of Cultured Rat Cortical Cells. (흰쥐 대뇌세포의 저산소증 모델에서 황련의 활성산소 생성 억제와 신경세포사 억제)

  • Choi, Ju-Li;Shin, Gil-Jo;Lee, Won-Chul;Moon, Il-Soo;Jung, Seung-Hyun
    • Journal of Life Science
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    • v.18 no.3
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    • pp.311-317
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    • 2008
  • Pathophysiological oxidative stress results in neuronal cell death mainly due to the generation reactive oxygen species (ROS). In low oxygen situation such as hypoxia and ischemia, excessive ROS is generated. Coptidis Rhizoma (CR) is a traditional medicine used for the incipient stroke. In this report we show that CR water extracts $(1\;{\mu}g/ml)$ exhibited protective effects of neuronal cell death in a hypoxic model (2% $O_2/5%\;CO_2,\;37^{\circ}C,$ 3 hr) of cultured rat cortical cells. We further show that CR water extracts significantly reduced the intensity of green fluorescence after staining with $H_2DCF-DA$ on one hour and three days after hypoxic shock and in normoxia as well. Our results indicate that CR water extracts prevent neuronal death by suppressing ROS generation.

Three-Dimensional Culture of Thymic Epithelial Cells Using Porous PCL/PLGAComposite Polymeric Scaffolds Coated with Polydopamine (폴리도파민으로 코팅된 다공성 PCL/PLGA 복합 폴리머 지지체를 이용한 흉선상피세포의 3차원 세포배양)

  • Seung Mi Choi;Do Young Lee;Yeseon Lim;Seonyeong Hwang;Won Hoon Song;Young Hun Jeong;Sik Yoon
    • Journal of Life Science
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    • v.33 no.8
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    • pp.612-622
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    • 2023
  • T-cell deficiency may occur in various clinical conditions including congenital defects, cell/organ transplantation, HIV infection and aging. In this regard, the development of artificial thymus has recently been attracting much attention. To achieve this aim, the development of techniques for 3D culture of thymic stromal cells is necessary because thymocytes grown only in a 3D thymic microenvironment can be differentiated fully to become mature, immunocompetent T cells; the same cannot be achieved for thymocytes grown in 2D. This study aimed to develop a nanotechnology-based 3D culture technique using polymeric scaffolds for thymic epithelial cells (TECs), the main component of thymic stromal cells. Scanning electron microscopic observation revealed that the pores of both PCL and PCL/PLGA scaffolds were filled with TECs. Interestingly, TECs grown in 3D on polydopamine-coated scaffolds exhibited enhanced cell attachment and proliferation compared to those grown on non-coated scaffolds. In addition, the gene expression of thymopoietic factors was upregulated in TECs cultured in 3D on polydopamine-coated scaffolds compared to those cultured in 2D. Taken together, the results of the present study demonstrate an efficient 3D culture model for TECs using polymeric scaffolds and provide new insights into a novel platform technology that can be applied to develop functional, biocompatible scaffolds for the 3D culture of thymocytes. This will eventually shed light on techniques for the in vitro development of T cells as well as the synthesis of artificial thymus.