• The Journal of Advanced Prosthodontics
• /
• 제6권5호
• /
• pp.379-386
• /
• 2014

PURPOSE. These days, mesenchymal stem cells (MSCs) have received worldwide attention because of their potentiality in tissue engineering for implant dentistry. The purpose of this study was to evaluate various growth inducing factors in media for improvement of acquisition of bone marrow mesenchymal stem cells (BMMSCs) and colony forming unit-fibroblast (CFU-F). MATERIALS AND METHODS. The mouse BMMSCs were freshly obtained from female C3H mouse femur and tibia. The cells seeded at the density of $10^6$/dish in media supplemented with different density of fetal bovine serum (FBS), $1{\alpha}$, 25-dihydroxyvitamin (VD3) and recombinant human epidermal growth factor (rhEGF). After 14 days, CFU-F assay was conducted to analyze the cell attachment and proliferation, and moreover for VD3, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was additionally conducted. RESULTS. The cell proliferation was increased with the increase of FBS concentration (P<.05). The cell proliferation was highest at the density of 20 ng/mL rhEGF compared with 0 ng/mL and 200 ng/mL rhEGF (P<.05). For VD3, although the colony number was increased with the increase of its concentration, the difference was not statistically significant (P>.05). CONCLUTION. FBS played the main role in cell attachment and growth, and the growth factor like rhEGF played the additional effect. However, VD3 did not have much efficacy compare with the other two factors. Improvement of the conditions could be adopted to acquire more functional MSCs to apply into bony defect around implants easily.

• 한국해양바이오학회지
• /
• 제7권2호
• /
• pp.52-57
• /
• 2015

The purpose of this study was to investigate a relationship between ultraviolet radiation and initial cell density (ICD) of microalgae using a floating marine photobioreactor (PBR). To examine the effect of ultraviolet (UV) radiation in sunlight on biomass productivity as a function of ICD, 0.5-L floating PBRs covered with or without UV cut-off film were placed in an outdoor rectangular tank containing 200 L of water. At the lower ICDs, 0.01 and 0.05 g/L, biomass productivities in the PBRs without UV cut-off film decreased by $278{\pm}21%$ and $222{\pm}3%$ compared with those with the film, respectively. In contrast, the presence of UV cut-off film did not have a significant effect on biomass productivities at the higher ICDs, 0.25 and 1.25 g/L. When the differences in biomass productivity made by the UV cut-off film were plotted against the sum of cell projection area per light receiving area of the PBR, the results revealed that the inhibitory effect of UV on biomass productivity can be negligible when the sum of cell projection area is equal to the light receiving area of the PBR. These results show that photoinhibition caused by UV radiation could be eliminated via operating the PBR with a proper ICD.

• 마이크로전자및패키징학회지
• /
• 제30권1호
• /
• pp.71-78
• /
• 2023

외부로부터 전원이 인가되지 않은 바이폴라 전극의 정량적 고찰을 통해 도금 두께 산포 개선의 가능성을 살펴보고자 하였다. 헐셀은 양극에 대해 기울어진 음극을 가짐으로써, 음극의 각 영역에서 양극에 대한 경로차에 의한 iR drop의 차이로 음극 근처의 전해액에서는 전위 분포가 다르게 되어 한눈에 다양한 반응 과전압에서의 전기화학적 반응성을 평가할 수 있다. 본 연구는 이러한 헐셀의 불균일한 전위분포에 대해 보조 양극이 있는 경우에 바이폴라 특성을 관찰하고자 하였다. 특히 이러한 바이폴라 특성을 활용하여 음극의 불균일 두께 산포를 개선할 수 있는 가능성을 평가하기 위해, 실험 및 시뮬레이션을 통해 검증하였으며, 이를 통해 바이폴라가 형성된 주변의 전위 및 전류밀도 분포를 분석해 보았다. 10 mA/cm² 전류밀도로 75분동안 도금을 진행하여, 평균 두께가 약 16 ㎛로 도금을 진행하였다. 보조 양극을 사용하지 않은 일반 헐셀에서는 두께의 표준 편차가 10 ㎛인 반면에 보조 양극을 사용한 경우에는 3.5 ㎛로 나타났다. 시뮬레이션 계산에서도 8.9 ㎛와 3.3 ㎛로 나타났으며, 비교적 실험결과와 시뮬레이션 결과의 정합성이 높은 것으로 나타났다. 이러한 보조 양극을 통해 외부에서 전원 인가를 하지 않더라도 바이폴라 현상에 의해 두께 산포가 개선될 수 있음을알 수 있었다.

• 한국식생활문화학회지
• /
• 제25권3호
• /
• pp.350-356
• /
• 2010

DPPH 라디칼 소거 활성 측정 결과 발효장뇌삼엽차의 추출물이 장뇌삼엽차의 추출물보다 활성이 더 높은 것으로 나타났다. 또한 장뇌삼과 발효장뇌삼이 장뇌삼엽차와 발효장 뇌삼엽차보다 항산화 활성이 높은 결과를 얻었다. 장뇌삼과 발효장뇌삼의 항산화 활성은 비슷하였다. SOD 유사활성도 측정에서는 대조군인 vitamin C와 비교할 때 모든 군이 SOD 유사활성도가 약한 것으로 분석되었다. 아질산염 소거능은 pH 1.2, 3.0의 조건에서 1 mg/mL의 농도로 처리 하였을 때 아질산염 소거능이 장뇌삼엽차, 발효장뇌삼, 장뇌삼, 발효장뇌삼의 순으로 높은 것으로 나타났고, pH 6.0의 조건에서는 모든 군이 아질산염 소거능이 약한 것으로 분석되었다. HeLa cell에서 시료 중 장뇌삼과 발효장뇌삼엽차의 추출물이 1 mg/mL의 농도에서 30% 이상의 암세포 증식 억제율을 나타내었다. 발효장뇌삼과 장뇌삼엽차는 각각 약 24%, 22%로 분석되었다. MCF-7 cell 발효장뇌삼과 장뇌삼엽차의 추출물이 1 mg/mL의 농도에서 27% 이상의 암세포 증식 억제율을 나타내어 비슷하였고, 장뇌삼 추출액이 21%로 가장 낮았으며, 발효장뇌삼엽차 추출액이 70% 이상으로 나타나 암세포 증식 억제율이 각 시료 중 가장 높은 것으로 분석되었다.

• 한국미생물·생명공학회지
• /
• 제31권3호
• /
• pp.211-215
• /
• 2003

고함량 RMh 효모인 Saccharomyces cerevisiae MTY62를 당밀과 com steep liquor를 공급하는 유가배양에서, 세포농도는 45g-DCW/L 이하, RNA 함량은 140mg/g-cell 로 얻어졌다. 이는 균체증식과 RMh축적에 당밀 내에 존재하는 저해물질 때문으로 생각되어 이를 제거하기 위해 다양한 당밀 전처리제의 효과를 조사하였다. 당밀로부터 금속이온 제거 효과는 Na2HPO4와 EDTA를 혼합 처리했을 때 $Ca^{++}$ 는 90% 이상 $Cu^{++}$ 는 약 80% 제거하는 결과를 나타내었고, Na2HPO4와 EDTA, IonClear BigBead 등의 3가지를 혼합 처리했을 때는 $Ca^{++}$ , $Cu^{++}$ 둘 다 90% 이상 제거되는 결과를 나타내었다. Na2HPO4+EDTA처리 당밀의 경우세포내 invertase활성을 크게 증가시켰다. 전처리 당밀로 회분배양한 결과, 세포농도는 18.6g-DCW/L, RNA농도는 3127mg/l, 최대비증식속도($\mu_{max}$ )는 0.459 $h^{-1}$ , 환원당 비소모속도(g-sugar/g-cell$.$h)는 1.28로,대조구에 비해 각각 10%, 17%, 47%, 36%로 증가한 값을 보였다.

• 대한영양사협회학술지
• /
• 제9권1호
• /
• pp.71-80
• /
• 2003

Food intake patterns and iron nutritional status of male and female college students were studied based on dietary iron density. Dietary data were collected using the method of 24-hour recalls for 3 consecutive days from 106 students, and fasting blood were drawn to measure iron nutritional status indicators such as total iron binding capacity, serum iron, hematocrit, hemoglobin, and red blood cell count. Mean daily iron intakes of male and female students were 13.3㎎ and 10.0㎎, which were 107% and 63% of the RDA, respectively. However, dietary iron density were similar between male and female students as 5.9㎎/1,000㎉ and 5.7㎎/1,000㎉, respectively. The diets were divided into two groups according to iron density; high iron density group (6㎎/1,000㎉ or more) and low iron density group (less than 6㎎/1,000㎉). The students in high density group had lower intakes of energy, especially fat, than those in low density group. Female students in high density group showed significantly higher intakes of iron, and non-heme iron and folate than those of low density group. The students in high density group consumed more rice, hamburger, and eggs, while those in low density group consumed more Ra-myon and alcoholic beverages. The students in high density group consumed greater proportions of iron from plant-origin foods. Vegetables, legumes and seasonings were the food groups that female students in high density group consumed significantly more than those in low density group. Also the percentages of female students with iron deficiency were higher in low density group. These results suggest that diet with high iron density is important to improve iron nutritional status of women, and further research about the effective way to increase iron density in our diet is needed.

• 한국산학기술학회논문지
• /
• 제14권5호
• /
• pp.2524-2528
• /
• 2013

일반적인 독립기포형 경질폴리우레탄 폼을 만들기 위한 formulation으로부터 개방기포형 경질 우레탄 폼을 얻기 위하여 반응성 기포개방제로서 1-butanol 및 12HSA (12-hydroxystearic acid)의 금속염인 Li-12HSA를 첨가제로 사용하여 만들어진 샘플의 물성과 기포개방 특성에 관한 연구를 진행하였다. 4.0 phr의1-butanol을 단독으로 사용할 때에 비하여 2 phr의 Li-12HSA를 복합하여 사용할 때의 기포개방율은 10.5%에서 98.0%로 현저한 개선효과를 나타내었다. 연구의 결과로서, 반응에 의하여 부피가 큰 막대형 분자를 우레탄 측쇄로 도입함으로서 독립기포형 경질 우레탄 폼의 기포크기나 밀도, 및 열전도율 등의 큰 변화없이 완전 개방기포형 경질 우레탄 폼을 얻을 수 있음을 보여주었다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.3197-3202
• /
• 2007

An analysis program for pedestrian flow has been developed to investigate the flow patterns of passenger in railway stations. Analysis algorithms for pedestrian flow based on DEM(Discrete Element Method) are newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. By using the developed program, we compared the simulation results of the effects of the location and size of exit and elapsed time.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.266-266
• /
• 2009

For the development of hybrid supercapacitor, increasing energy density is one of the most crucial matters. Since the energy density is the function of capacitance and voltage, it is necessary to enhance energy density for increasing capacitance or voltage. For the high working voltage, it was to enforce Li ion free-doping to activated carbon. As a result, initial capacitance has increased by 11% than raw cell. But capacitance has decreased by Li ion re-solution to electrolyte for increase the number of cycle.

• 한국철도학회논문집
• /
• 제8권4호
• /
• pp.337-341
• /
• 2005

Algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed. In the new algorithm, there are many similarity between multi phase flow and passenger flow. The velocity component of 1st phase corresponds to the direction vector of cell, each particle to each passenger, volume fraction to population density and the momentum equation of particle to the walking velocity equation of passenger, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger, To verify the effectiveness of new algorithm, passenger flow analysis for simple railway station model is conducted. The results for passenger flow in the model station are satisfying qualitatively and quantitatively.