• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2003.05a
• /
• pp.375-380
• /
• 2003

This study is concerned with the machine part grouping m cellular manufacturing. To group machines into the set of machine cells and parts into the set of part families, new p-median model considering the production data such as the operation sequences and production volumes for parts is proposed. Unlike existing p-median models relying on the classical binary part-machine incidence matrix which does not reflect the real production factors which seriously impact on machine-part grouping, the proposed p-median model reflects the production factors by adopting the new similarity coefficient based on the production data-based part-machine incidence matrix of which each non-binary entry indicates actual intra-cell or inter-cell flows to or from machines by parts. Computation test compares the proposed p median model favorably.

• Journal of Microbiology and Biotechnology
• /
• v.3 no.4
• /
• pp.238-243
• /
• 1993

In the suspension cultures of Eschscholtzia californica, phytohormone effects showed that alkaloid production was increased by IAA treatment without kinetin in both volumetric and specific way. Kinetin, however, suppressed alkaloid accumulation. Addition of ethephon inhibited cell growth. However, it enhanced the alkaloid production significantly in both volumetric and specific way. IAA promoted alkaloid production during elicitation. The highest alkaloid accumulation was observed at 5 $\mu$ M of IAA. Ethephon also enhanced alkaloid production during elicitation. The highest alkaloid formation was observed at 460 mg/l of ethephon with elicitation. Elicitation with ethephon, however, altered cell growth and the pattern of benzophenanthridine alkaloids production.

• KSBB Journal
• /
• v.15 no.6
• /
• pp.609-614
• /
• 2000

Suspension cultures of Camptotheca acuminata, which is known to produce the anticancer indole alkaloid camptothecin and its derivatives, were made to increase camptothecin production. The capability of camptothecin production in suspended cells is decreased by repeated subculturein. Aggregated cells produced more camptothecin than single cells. Optimal cell aggregation was achieved in hybrid medium supplemented with 4% sucrose. Aggregated cells in hybrid medium with 4% sucrose produced $18.04{\times}10^{-4} mg/L$ of camptothecin. The control of shaking speeds was effective at inducing cell aggregation and camptothecin production. A shaking speed of 100 rpm was found optimum to increase the cell aggregation with a camptothecin production of $19.4{\times}10^{-4} mg/L$.

• Journal of Ginseng Research
• /
• v.36 no.1
• /
• pp.61-67
• /
• 2012

In the present study, effects of sun ginseng (SG) on the collagen synthesis and the proliferation of dermal fibroblast were investigated. Collagen synthesis was measured by assaying procollagen type I C-peptide production. In addition, the level of matrix metalloproteinase (MMP)-1 was assessed by western blot analysis. SG suppressed the MMP-1 protein level in a dose-dependent manner. In contrast, SG dose-dependently increased tissue inhibitors of MMP (TIMP)-1 production in fibroblasts. SG increased type I collagen production directly and/or indirectly by reducing MMP-1 and stimulating TIMP-1 production in human dermal fibroblasts. SG dose-dependently induced fibroblast proliferation and this, in turn, can trigger more collagen production. These results suggest that SG may be a potential pharmacological agent with anti-aging properties in cultured human skin fibroblast.

• Applied Chemistry for Engineering
• /
• v.35 no.5
• /
• pp.438-444
• /
• 2024

Lipid-extracted algae (LEA) cell residue is generated as an organic solid waste in the process of biodiesel production from microalgae, and its recycling or reuse is important in the aspect of waste minimization. In this study, the influence of the addition of LEA hydrolysate to Chlorella vulgaris (C. vulgaris) cultivation on cell growth and biodiesel production was investigated to seek a possible use of LEA as a carbon source. LEA was hydrolyzed by three different methods: acid hydrolysis, autoclave, and ultra-sonication. The resulting hydrolysates were supplemented with three background media: formulated defined medium (BG-11), organic liquid fertilizer (PAL1), and distilled water. Both cell growth and lipid production of C. vulgaris were improved under mixotrophic cultivation. By supplementing hydrolysates, biomass productivity was increased several folds because the LEA hydrolysates contained monosaccharides such as glucose and galactose. Lipid contents and biodiesel productivity were bestly increased in PAL1 medium supplemented with ultrasonication (UL) hydrolysate, from 11 to 25% after 14 days, while nitrate concentration was quickly reduced from 55 to below 10 mg/L. The suggested recycling option of the LEA to microalgae cultivation was helpful to improve biodiesel productivity as well as to reduce organic waste generation.

• IMMUNE NETWORK
• /
• v.3 no.3
• /
• pp.188-200
• /
• 2003

Background: Immunization of dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. In this study, we examined whether the uptake of necrotic tumor cells could modulate DC phenotypes and whether the immunization of necrotic tumor cell-loaded DCs could elicit efficient tumor specific immune responses followed by a regression of established tumor burdens. Methods: We prepared necrotic tumor cell-pulsed DCs for the therapeutic vaccination and investigated their phenotypic characteristics, the immune responses induced by these DCs, and therapeutic vaccine efficacy against colon carcinoma in vivo. Several parameters including phagocytosis of tumor cells, surface antigen expression, chemokine receptor expression, IL-12 production, and NK as well as CTL activation were assessed to characterize the immune response. Results: DCs derived from mouse bone marrow efficiently phagocytosed necrotic tumor cells and after the uptake, they produced remarkably increased levels of IL-12. A decreased CCR1 and increased CCR7 expression on DCs was also observed after the tumor uptake, suggesting that antigen uptake could induce DC maturation. Furthermore, co-culturing of DCs with NK cells in vitro enhanced IL-12 production in DCs and IFN-${\gamma}$ production in NK cells, which was significantly dependent on IL-12 production and cell-to-cell contact. Immunization of necrotic tumor cell-loaded DCs induced cytotoxic T lymphocytes as well as NK activation, and protected mice against subsequent tumor challenge. In addition, intratumoral or contra-lateral immunization of these DCs not only inhibited the growth of established tumors, but also eradicated tumors in more than 60% of tumor-bearing mice. Conclusion: Our data indicate that production of IL-12, chemokine receptor expression and NK as well as CTL activation may serve as major parameters in assessing the effect of tumor cell-pulsed DC vaccine. Therefore, DCs loaded with necrotic tumor cells offer a rational strategy to treat tumors and eventually lead to prolonged survival.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.338-341
• /
• 2000

An internal membrane bioreactor system was employed for continuous succinic ac id production from glucose in order to prove its performance and practicality. Succinic acid-producing Anaerobiospirillum succiniciproducens required more $CO_2$ for the proper growth and succinic acid production in cell recycled continuous culture than in batch culture. The maximum productivity obtained in cell recycled continuous culture was about 3.3 g/L-h which was ca. 3.3 times higher than that obtained in batch culture.

• Journal of Hydrogen and New Energy
• /
• v.20 no.5
• /
• pp.416-423
• /
• 2009

High-temperature steam electrolysis (HTSE) using solid oxide cell is a challenging method for highly efficient large-scale hydrogen production as a reversible process of solid oxide fuel cell (SOFC). The overall efficiency of the HTSE hydrogen and synthesis gas production system was analyzed thermo-electrochemically. A thermo-electrochemical model for the hydrogen and synthesis gas production system with solid oxide electrolysis cell (SOEC) and very high temperature gas-cooled reactor (VHTR) was established. Sensitivity analyses with regard to the system were performed to investigate the quantitative effects of key parameters on the overall efficiency of the production system. The overall efficiency with SOEC and VHTR was expected to reach a maximum of 58% for the hydrogen production system and to 62% for synthesis gas production system by improving electrical efficiency, steam utilization rate, waste heat recovery rate, electrolysis efficiency, and thermal efficiency. Therefore, overall efficiency of the synthesis production system has higher efficiency than that of the hydrogen production system.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.1
• /
• pp.8-13
• /
• 1998

Animal cells in culture typically convert most of the glucose they consume into lactate. The accumulation of lactate, however, is commonly cited as one of the factors that inhibit cell growth and limit the maximum cell concentration that can be achieved in culture. The specific production of lactate and the amount of glucose converted to lactate can be reduced when cells are grown in a fed-batch culture in which the residual glucose concentration is maintained at low levels. Such a fed-batch culture was used to grow and adapt hybridoma cells into a low-lactate-producing state before changing into continuous culture. The cells reached and maintained a high viable cell concentration at steady state. In a similar manner, cells that were initially grown in batch culture and a glucose-rich environment reached a steady state with a cell concentration that is much lower. The feed composition and dilution rates for both cultures were similar, suggesting steady state multiplicity. From a processing perspective the desired steady state among those is the one with the least metabolite production. At such seady state nutrient concentration in the feed can be further increased to increase cell and product concentrations without causing the metabolite inhibitory effect typically seen in a cell culture. Controlling cell metabolism in a continuous culture to reduce or eliminate waste metabolite production may significantly improve the productivity of mammalian cell culture processes.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.22 no.1
• /
• pp.108-119
• /
• 2009

Objectives : This study was carried out to investigate the effects of Samhwangseje(SHSJ) on anti-Inflammation in Raw 264.7 cell. Methods : The effects of SHSJ on anti-Inflammation were measured by the cytotoxicity of Raw 264.7 cell, the inhibition for NO, TNF-$\alpha$, $PGE_{2}$, iNOS and COX-2, the blocking NF-${\kappa}B$ into nucleus. Results : 1. All concentrations of SHSJ had no cytotoxicity in Raw 264.7 cell. 2. All concentrations of SHSJ inhibited the production of NO in the Raw 264.7 cell stimulated with LPS. 3. All concentrations of SHSJ did not inhibit the production of TNF-$\alpha$ in the Raw 264.7 cell stimulated with LPS. 4. All concentrations of SHSJ inhibited the production of $PGE_{2}$ in the Raw 264.7 cell stimulated with LPS. 5. All concentrations of SHSJ did not inhibit the expression of COX-2 but concentrations of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$ SHSJ inhibited iNOS expression in the Raw 264.7 cell stimulated with LPS. 6. Concentrations of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$ SHSJ had the effect of blocking NF-${\kappa}B$ into nucleus in LPS-induced macrophage Raw 264.7 cell.