• 한국미생물·생명공학회지
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• 제17권3호
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• pp.241-246
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• 1989

Quadrupole mass spectrometer를 이용한 발효 배기가스의 분석을 통해 세포의 증식을 on-line monitoring하고자 model 균주로 Candida utilis에 대해 연구하였다. Quadrupole mass spectrometer와 interface된 16-bit 개인용 컴퓨터 (IBM PC-AT)에서 산소 소비속도(OUR)와 이산화탄소 발생속도(CER)를 on-line 계산할 수 있었고 계속해서 이들 계산치로부터 세포농도와 증식속도 및 비증식속도를 계산하였다. 계산된 값들은 실험적으로 측정한 세포농도 및 비증식속도와 잘 일치함을 알 수 있었다.

• 대한한방부인과학회지
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• 제15권4호
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• pp.1-16
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• 2002

This work examines the effect of treatment with Gyukhachukeotang on the growth of uterine myomal cells. Comparisons of cell growth, MAP kinase activity and expression of bcl-2 (apoptosis-related gene) were made between the control and experimental samples. The results as fallows; 1. Any concentration of Gyukhachukeotang above 0.01% yielded growth inhibition. Concentrations of 5% and 10% stopped all cell growth, demonstrating the effectiveness of Gyukhachukeotang as a growth inhibitor on uterine myomal cells. 2. The MAP kinase activity in uterine myomal cells treated with Gyukhachukeotang was decreased to a high degree at the concentration of 10%, and some inhibition of activity was detected at a concentration of 5%. 3. The expression of bcl-2, a Cell Apoptosis-related gene, in uterine myoma cells treated with Gyukhachukeotang was gradually increased with increasing concentration of Gyukhachukeotang. These results indicate the ability of Gyukhachukeotang to control uterine myomal cell growth, with concurrent reduction of MAP kinase activity. Treatment with Gyukhachukeotang appears to trigger a normal apoptosis response, as indicated by increased bcl-2 expression. This observed increase in apoptosis indicates that Gyukhachukeotang is an appropriate prescription to treat uterine myomal cells.

• KSBB Journal
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• 제28권1호
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• pp.24-30
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• 2013

Dissolved oxygen, pH and cell concentration have been online monitored in cultivation processes with Escherichia coli by using a $MABOOMS^{TM}$ (microplate-based bioreactor with optical online monitoring systems). Fluorescent sensing membranes containing Ru ${(dpp)_3}^{2+}$ or HPTS were prepared with GA sol-gel matrix and coated into a well of a 24-well microplate. Fluorescence intensity was measured and correlated to the dissolved oxygen or pH. Cell concentrations were also online monitored by measuring optical reflectance at 650 nm. A well of a 24-well microplate could also be divided into 4 parts, each of which was coated with fluorescent sensing membranes for the detection of dissolved oxygen or pH. The 24-well microplate coated with fluorescent sensing membranes or a 4-divided sensing membrane. was used to online monitor the dissolved oxygen, pH and cell concentration during E. coli cultivations. The online monitoring results showed the characteristics of cell growth in cultivation processes very well.

• KSBB Journal
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• 제13권3호
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• pp.272-278
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• 1998

Cell recovery from high cell density broths of Alcaligenes eutrophus by pretreatment with aluminum-based coagulants such as aluminum sulfate, polyaluminum hydrooxide chloride silicate (PACS), and polyaluminum hydrooxide chloride (Hi-PAX) was carried out. Cells coagulated with coagulants could be successfully recovered above 95-99% by centrifugation or filtration. The optimum initial pH of fermentation broths for cell recovery was in the range of 10 to 12. Optimum coagulants dosage for cell recovery increased with increasing of cell concentrations (21-160 g/L). The optimum coagulant dosages to recover cells with more than 95% cell recovery by centrifugation for the cell concentrations ranged 21-160 g/L were as follows: aluminum sulfate, 416-1708 mg Al/L; PACS, 211-826 mg Al/L; Hi-PAX, 320-960 mg Al/L. At optimum conditions for the coagulation of cells, centrifugal forces for 95% of cell recovery were dependent on the cell concentration. The centrifugal forces at 82 g/L and 160 g/L of cell concentration were only 45${\times}$g and 1600${\times}$g, respectively.

• 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.

• 한국생활과학회지
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• 제17권5호
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• pp.1027-1035
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• 2008

Essentail oils and carrier oils are generally used for Aromatherapy. Therefore the toxicity, possibilities of irritations and sensitive reactions and injury of essential oils must be considered for clients and therapists. So that, in this studies a toxicity of jojoba and 4 species essential oils (fennel, mandarine, tea tree and cedarwood) were investigated by the measurement of MTT-assay and sirius red staining. Liver, kidney and brain tell were chosen for the cell viability assay and observation of morphological change. In the result, no cytotoxicity was observed on live., kidney and brain cell at concentration of 0.01 $\mu\el/m\el$ jojoba oil. And lysis and nucleus breaking were not observed at same concentration of jojoba oil on live., kidney and brain cell. fennel oil was showed 50% of cell viability and inhibited cell growth on liver, kidney and brain cell at relatively high concentration compared with the other oils. 50% of liver, kidney and brain cell viability and delayed cell growth of tea tree and mandarine oil were revealed at lower concentration than fennel oil. In cedarwood oil, 50% of liver cell viability at concentration of 0.00067 $\mu\el/m\el$ was showed, but cell viability and cell growth of kidney and beam cell were effected at the lowest concentration compared with other oils. So that, jojoba oil as using of carrier oil may be not harmful. And 3 essential oils from the fennel, tea tree and mamdarine may have very low toxicity, but cedarwood may be used carefully for inhalation. And over dosage of concentrated cedarwood oil should be not directly touched and exposured, and absolute essential oils must be diluted with carrier oils for topical and systematic massage.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1990년도 제12회 학술강연회초록집
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• pp.58-62
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• 1990

The size and concentration of wear debris in lubricating oil often reveal the operating condition of the rotating machinery. To evaluate the possible application of light attenuation measurement for the estimation of wear debris concentration in the lubricating oil, the light transmittance through the lubricating oil cell contaminated with various concentrations of diatomite particles was measured, the attenuation coefficient was estimated from the transmittance measurement and the coefficients were compared with those obtained from the scattering theory. The comparision showed good agreements between them. It is also noted that the experimentally determined attenuation coefficient showed almost linear relation with particle weight concentrations for the concentrations within the range of 2000 ppm. For the case of 0 ppm weight concentration of diatomite particles in the lubricating oil cell, the thickness of the cell required to give $100 \mu W$ light attenuation is 7.75 mm. This result indicates that the light attenuation method will be one of the possible candidates of machine failure diagnostic sensors for the estimation of wear debris concentration in the lubricating oil.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.245-246
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• 2000

Agrobacterium sp.에 의해 생산되는 커들란은 2차 부산물이기 때문에 이의 생산을 증대시키기 위해서는 고농도 세포배양이 필요하다. 본 연구에서는 고농도 세포배양을 실현하기 위하여 탄소원 과 질소원을 제어 공급하는 방법을 이용하였다. 초기 탄소원의 농도가 20g/L일 때 24시간 내에 모두 소모되었으며 생산된 세포의 농도는 6g/L였다. 고농도의 탄소원을 이용하여 배양조내의 설탕의 농도가 10g/L 이상이 되도록 제어하는 방법을 사용하였다.

• Applied Science and Convergence Technology
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• 제23권1호
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• pp.27-33
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• 2014

We have studied photovoltaic characteristics of single-junction GaAs solar cells with/without an $MgF_2/ZnS$ anti-reflective coating (ARC) illuminated by low-density concentration (<10 suns). By the ARC deposition, the short-circuit current density ($J_{SC}$) and the fill factor (FF) are increased by $5mA/cm^2$ and 5% at a standard illumination (1 sun), respectively, and the resulted conversion efficiency is enhanced by 45%. In contrast with the cell with no ARC showing a rapid degradation with increasing concentration power, the efficiency of ARC-deposited cell remains almost constant as ($17.7{\pm}0.3$)% regardless of the concentration. It informs that ARC treatment is very effective in GaAs concentrator solar cells.

• 한국식품과학회지
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• 제51권2호
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• pp.188-191
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• 2019

In this study, the poor electro-transformant yield of large DNA in bifidobacteria was improved by increasing the DNA concentration, which was amplified by enhancing electroporation conditions: treating the cell wall weakening agent and cell membrane permeabilizing molecule as well as changing the electrical parameter. In the enhanced conditions, the electroporation frequency increased from 15 to 71 times compared to the initial conditions at the same DNA concentration. As the DNA concentration increased, the difference in the electroporation frequency between the two conditions became greater, and the curve of the enhanced conditions seemed to be saturated with a DNA concentration over $4{\mu}g$. The present study provided a clue to the recovery of the electroporation frequency with large DNA and formulated the relationship between the DNA concentration, the DNA size and the electroporation frequency in bifidobacteria. Therefore, this study will contribute to the expansion of molecular genetic studies of bifidobacteria.