• 제목/요약/키워드: maximum cell density

검색결과 429건 처리시간 0.023초

Expression of Osteopontin in Non-small Cell Lung Cancer and Correlative Relation with Microvascular Density

  • Yu, Ting-Ting;Han, Zhi-Gang;Shan, Li;Tao, Jie;Zhang, Tao;Yuan, Shuai-Fei;Shen, Hong-Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권1호
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    • pp.29-32
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    • 2014
  • Background and Objective: Lung cancer is one of the malignant diseases which most seriously threat humansurvival and development. This study aimed to assess osteopontin (OPN) expression in non-small cell lung cancer (NSCLC) and any relationship with clinicopathological features. Methods: Immunohistochemistry was used to determine OPN expression and microvascular density (MVD) in 120 cases of NSCLC also undergoing clinical assessment. Results: Moderately positive expression of OPN was found in 34.6% (41/120) and strong expression in 47.5% (57/120) of the NSCLCs; OPN expression in carcinomas was higher than in pericarcinoma tissues (P<0.05). While no obvious association was observed with NSCLC patient age, gender, maximum diameter of the tumor and pathological type, OPN expression was more commonly detected in poorly differentiated carcinoma tissue and lymph node metastasis as well as at advanced clinical stage (P<0.05); OPN expression in cancer tissue was positively correlated with MVD (r = 0.839, P = 0.000). Conclusion: OPN plays an important role in promoting tumor angiogenesis and progress of NSCLCs and has the possibility to become the new target for therapy.

박실지와 정양지의 식물플랑크톤 군집의 계절 변동 (Seasonal Changes of Phytoplankton Communities in the Paksil and Jungyang Marshes)

  • 이경락;최재신;김한순
    • ALGAE
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    • 제18권4호
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    • pp.273-280
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    • 2003
  • The physico-chemical characteristics and seasonal variations of phytoplankton community were investigated in the Paksil and Jungyang marshes. Water and phytoplankton samples for analyses were collected monthly from April 2002 to March 2003. A total of 421 taxa of phytoplankton belonging to eight classes identified. The number of taxa was highest in Bacillariophyceae, followed by Chlorophyceae, Euglenophyceae, Cyanophyceae, Chrysophyceae, Dinophyceae, Xanthophyceae and Cryptophyceae. The standing crops ranged from 1.25 ${\times}$ $10^6$ to 5.85 ${\times}$ $10^6$ cells ${\cdot}l^{-1}$ in Paksil marsh and 0.25 to 9.63 ${\times}$ $10^6$ cells ${\cdot}l^{-1}$ in Jungyang marsh. The highest algal density at Paksil marsh was recorded in October during the high development of Chlorococcales while the lowest value occured in July. In the Jungyang marsh, the maximum algal density was recorded in October when Cryptomonas sp. and Mallomonas sp. accounted for 64% to total cell numbers and the lowest cell density was observed in January due to the decrease of Chlorophyceae. The dominant species were represented by Euglena proxima, Trachelomonas oblonga, Trachelomonas volvocina of Euglenophyceae, Dictyosphaerium pulchellum, Monoraphidium griffithii, Oocystis parva of Chlorophyceae, Dinobryon sertularia, Kephyrion rubri-claustri of Chrysophyceae, Achnanthes minutissima of Bacillariophyceae and Cryptomonas sp. of Cryptophyceae in the Paksil and Jungyang marshes. Phytoplankton diversity(H’) and dominance index varied rather irregularly throughout the sampling period but they were significantly correlated. The highest diversity(H’Paksil = 3.68, H’Jungyang = 3.63) coincided with the lowest values of dominance(DPaksil = 0.05, DJungyang = 0.05)

Production of Sulfuric Acid and Ammonia Water from Ammonium Sulfate Using Electrodialysis with Bipolar Membrane and Ammonia Stripping

  • Yeon Kyeong-Ho;Song Jung-Hoon;Shim Bong-Sup;Moon Seung-Hyeon
    • Korean Membrane Journal
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    • 제7권1호
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    • pp.28-33
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    • 2005
  • The feasibility of producing sulfuric acid and ammonia water from ammonium sulfate was investigated by an integrated process including ammonia stripping (AS) and electrodialysis with bipolar membrane (EDBM). It was suggested that the production of sulfuric acid using ammonia stripping-electrodialysis with bipolar membrane (ASEDBM) was effective in obtaining high concentration of sulfuric acid compared with EDBM alone. AS was carried out over pH 11 and within the range of temperatures, $20^{\circ}C{\~}60^{\circ}C$. Sodium sulfate obtained using AS was used as the feed solution of EDBM. The recovery of ammonia increased from $40\%$ to $80\%$ at $60^{\circ}C$ due to the increased mobility of ammonium ion. A pilot-scale EDBM system, which is composed of two compartments and 10 cell pairs with an effective membrane area of $200 cm^2$ per cell, was used for the recovery of sulfuric acid. The performance was examined in the range of 0.1 M${\~}$1.0 M concentration of concentrate compartment and of $25 mA/cm^2{\~}62.5 mA/cm^2$ of current density. The maximum current efficiency of $64.9\%$ was obtained at 0.1 M sulfuric acid because the diffusion rate at the anion exchange membrane decreased as the sulfuric acid of the concentrate compartment decreased. It was possible to obtain the 2.5 M of sulfuric acid in the $62.5 mA/cm^2$ with a power consumption of 13.0 kWh/ton, while the concentration of sulfuric acid was proportional to the current density below the limiting current density (LCD). Thus, the integrating process of AS-EDBM enables to recover sulfuric acid from the wastewaters containing ammonium sulfate.

Experimental and Simulation Study of PEMFC based on Ammonia Decomposition Gas as Fuel

  • Zhao, Jian Feng;Liang, Yi Fan;Liang, Qian Chaos;Li, Meng Jie;Hu, Jin Yi
    • Journal of Electrochemical Science and Technology
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    • 제13권1호
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    • pp.63-70
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    • 2022
  • Compared with hydrogen, ammonia has the advantages of high gravimetric hydrogen densities (17.8 wt.%), ease of storage and transportation as a chemical hydrogen storage medium, while its application in small-scale on-site hydrogen production scenarios is limited by the need for complex separation equipment during high purity hydrogen production. Therefore, the study of PEMFC, which can directly utilize ammonia decomposition gas, can greatly expand the application of fuel cells. In this paper, the output characteristics, fuel efficiency and the variation trend of hydrogen concentration and local current density in the anode channel of fuel cell with the output voltage of PEMFC fueled by ammonia decomposition gas were studied by experiment and simulation. The results indicate that the maximum output power of the hybrid fuel decreases by 9.6% compared with that of the pure hydrogen fuel at the same inlet hydrogen equivalent. When the molar concentration of hydrogen in the anode channel is less than 0.12, the output characteristics of PEMFC will be seriously affected. Employing ammonia decomposition gas as fuel, the efficiency corresponding to the maximum output power of PEMFC is approximately 47%, which is 10% lower than the maximum efficiency of pure hydrogen.

고농도 세포배양에서 Bacillus thuringiensis의 세포 성장과 포자 형성 속도 (Growth Kinetics and Sporulation of Bacillus thuringiensis in High Cell Density Culture)

  • 강병철;장호남
    • KSBB Journal
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    • 제16권1호
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    • pp.30-35
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    • 2001
  • 유가식배양과 세라믹 막을 장착한 생물반응기에서 운전인 TCRC 조업을 통해서 Bacillus thuringiensis의 고농도 세포배양을 실시하였다. 유가식 배양에서 B. thuringiensis의 세포 성장은 선형적으로 증가하였고, 이것은 세포성장 모델리의 결과와 잘 맞았다. 낮은 세포 성장속에도 불구하고 유가식 배양동안에 포자형성은 관찰할 수 없었고, 이것은 연속배양의 결과와는 반대였다. 유가식 조업 후에 회분식 배양으로 바꾸면 300 g/L의 포도당 공급 농도를 사용했을 때 2.7$\times$$10^9$ CFU/mL 의 포자농도를 얻었다. 생물반응기내에 세라믹 막을 장착한 TCRC 조업에서 포도당 공급 농도의 영향을 결정하였다. 50 g/L의 포도당 농도를 사용했을 때 TCRC 조업에서 82.5 g-cell/L에 해당하는 최대 세포농도 1.8$\times$$10^{10}$ CFU/mL 를 얻었다. TCRC에서 세포성장은 선형적으로 증가하였고 포도당 농도는 제한되었는데 이것은 세포성장은 모델링의 결과와 잘 일치하였다. 1 g/L의 포도당을 공급한 경우 이외에는 TCRC 조업 동안에 포자형성을 관찰할 수 없었다. 50 g/L의 포도당을 공급한 경우 TCRC조업 후에 회분식 배양으로 전환시키면 1.2$\times$$10^{10}$ CFU/mL 의 포자농도를 얻었고, 이것은 연구된 여러 배양형태 중에 가장 높은 포자농도이다. 이 때 최적의 포도당 공급속도는 0.55 g glucose/h로 공급하였을 때였다.

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Enhancement of BDNF Production by Co-cultivation of Human Neuroblastoma and Fibroblast Cells

  • Hong, Jong-Soo;Oh, Se-Jong;Kim, Sun-Hee;Park, Kwon-Tae;Cho, Jin-Sang;Park, Kyung-You;Lee, Jin-Ha;Lee, Hyeon-Yong
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제3권2호
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    • pp.51-54
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    • 1998
  • It has been proved that co-cultivation of human neroblastoma cells and human fibroblast cells can enhance nerve cell growth and the production of BDNF in perfusion cultivation. In batch co-cultivation, maximum cell density was increased up to 1.76${\times}$106 viable cells/mL from 9${\times}$105 viable cells/mL of only neuroblastoma cell culture. The growth of neuroblastoma cells was greatly improved by culturing both nerve and fibroblast cells in a perfusion process, maintaining 1.5${\times}$106 viable cells/mL, which was much higher than that form fed-batch cultivation. The nerve cell growth was greatly enhance in both fed-batch and perfusion cultivations while the growth of fibroblast cells was not. It strongly implies that the factors secreted from human fibrobast cells and/or the environments of co-culture system can enhance both cell growth and BDNF secretion. Specific BDNF production rate was not enhanced in co-cultures; however, the production period was increased as the cell growth was lengthened in the co-culture case. Competitive growth between nerve cells and fibroblast cells was not observed in all cases, showing no changes of fibroblast cell growth and only enhancement of the neuroblastoma cell growth and overall BDNF production. It was also found that the perfusion cultivation was the most appropriate process for cultivating two cell lines simultaneously in a bioreactor.

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LSGM계 음극지지형 고체산화물 연료전지에 적용된 LDC 완충층의 효과 (Effect of the LDC Buffer Layer in LSGM-based Anode-supported SOFCs)

  • 송은화;정태주;김혜령;손지원;김병국;이종호;이해원
    • 한국세라믹학회지
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    • 제44권12호
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    • pp.710-714
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    • 2007
  • LSGM$(La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_{3-{\delta}})$ is the very promising electrolyte material for lower-temperature operation of SOFCs, especially when realized in anode-supported cells. But it is notorious for reacting with other cell components and resulting in the highly resistive reaction phases detrimental to cell performance. LDC$(La_{0.4}Ce_{0.6}O_{1.8})$, which is known to keep the interfacial stability between LSGM electrolyte and anode, was adopted in the anode-supported cell, and its effect on the interfacial reactivity and electrochemical performance of the cell was investigated. No severe interfacial reaction and corresponding resistive secondary phase was found in the cell with LDC buffer layer, and this is due to its ability to sustain the La chemical potential in LSGM. The cell exhibited the open circuit voltage of 0.64V, the maximum power density of 223 $mW/cm^2$, and the ohmic resistance of $0.17{\Omega}cm^2$ at $700^{\circ}C$. These values were much improved compared with those from the cell without any buffer layer, which implies that formation of the resistive reaction phases in LSGM and then deterioration of the cell performance is resulted mainly from the La diffusion from LSGM electrolyte to anode.

MFC의 금속 및 탄소전극에 의한 전기생산 특성과 오염저감 효과 (Electricity Generation and De-contamination Effect for Characteristic Electrode Material in a Microbial Fuel Cell System Using Bay Sediment)

  • 권성현;송형진;이은미;조대철;이인형
    • 한국환경과학회지
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    • 제19권8호
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    • pp.951-960
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    • 2010
  • Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. $0.57\;W/m^2$ Al/Graphite. Meanwhile, graphite-only electrodes produced max. $0.11\;W/m^2$ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was $0.64\;W/m^2$. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5~36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.

거제도 장목항에서 적조원인생물 Akashiwo sanguinea(Dinophyceae): 형태, 분자계통학적 특성 및 온도와 염분에 따른 성장 특성 (Bloom-forming dinoflagellate Akashiwo sanguinea(Dinophyceae) in Jangmok Harbour of Geoje Island, Korea: Morphology, phylogeny and effects of temperature and salinity on growth)

  • 한경하;;윤주연;강병준;김현정;서민호;서호영;신현호
    • 환경생물
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    • 제37권2호
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    • pp.119-128
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    • 2019
  • 거제도 장목항에서 분리한 Akashiwo sanguinea의 형태와 계통학적 특성을 명확히 하고, 여러 온도와 염분구배에 따른 성장조건을 파악하고자 하였다. A. sanguinea의 세포는 오각형이었고, 세포의 길이는 54.7~70.3 ㎛, 폭은 31.5~48.5 ㎛로 나타났다. 핵은 세포의 중심에 위치하였고, 엽록체는 황갈색으로 세포 전체에 퍼져있었다. 상추구는 알파벳 e 모양이었다. 계통분석 결과 장목항에서 분리한 본 배양주는 ribotype A에 포함되었다. 온도 및 염분구배에 따른 성장 실험은 5℃ 이하의 온도를 제외한 모든 온도구배에서 성장이 나타났다. 그리고, 최대성장속도는 온도 20℃, 염분 20 psu에서 0.50 day-1로 나타났고, 최대세포밀도는 온도 25℃, 염분 30 psu에서 1,372 cells mL-1였다. 이 결과는 A. sanguinea가 가을철에 한국 연안에서 최대 증식을 보일 수 있다는 것을 나타낸다.

Butyrate처리된 차이니즈 햄스터 난소세포에서 Hepatitis B 바이러스 인간화항체의 생산 (Production of Humanised Anti-hepatitis B Antibody in Butyrate-Treated Chinese Hamster Ovary Cells)

  • 박세철;이재선;이병규;강희일
    • 한국미생물·생명공학회지
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    • 제34권1호
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    • pp.47-51
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    • 2006
  • Sodium butyrate (NaBu) is used as an enhancer for the production of recombinant proteins in Chinese hamster ovary (CHO) cells. However, NaBu is well-known for its cytotoxic effect, thereby inducing apoptosis. CHO cells which had been engineered to express a humanised anti-HBV antibody were cultured using serum-free medium, Ex-cell 301. From a seeding density of $2{\times}10^5$ cells/ml, CHO cells grown with serum-free medium reached a maximum cell density of $1.3{\times}10^6$ cells/ml after 9 days in culture and produced a maximal antibody concentration of 130 mg/l after 13 days in culture. In the perfusion culture system, CHO cells producing anti-HBV antibody grown in an 7.5 1 bioreactor seeded with $2{\times}10^5$ cells/ml reached a maximal antibody concentration of 85 mg/1 after 720 h in culture. The addition of 0.3 mM NaBu and lowering culture temperature to $33^{\circ}C$ elongated the culture period to 60 days and increased the production yield by 2-fold, compared to control culture.