• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.403-405
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• 2000

This paper describes a single transistor type ferroelectric field effect transistor (1Tr FeFET) memory cell scheme, which select one unit memory cell and program/read it. The well voltage can be controlled by isolating the common row well lines. Through applying bias voltage to Gate and Well, respectively, we implement If FeFET memory cell scheme in which interference problem is not generated and the selection of each memory cell is possible. The results of HSPICE simulations showed the successful operations of the proposed cell scheme.

• 대한임상검사과학회지
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• 제52권1호
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• pp.53-61
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• 2020

Cell migration은 embryogenesis 혹은 cancer metastasis 이외에, 물리적 손상에 의한 상처의 수복을 위해서 손상된 부위로 세포가 이동하는 매우 흔하게 관찰되는 현상 중 하나 이다. Wound healing assay는 in vitro의 이차원 평면상에서 세포의 이동을 관찰할 수 있는 기본적인 연구 기법이다. In vitro상에서 물리적 손상을 재현하는 가장 손쉬운 접근법으로서, 세포의 confluent monolayer 표면에 날카로운 도구를 이용하여 기계적인 스크레치를 내는 방법이 사용되고 있다. 완충 스프링이 탑재된 금속 핀을 96-well plate를 기반으로 하는 wound maker에 장착하여 multi-well plate 바닥 표면의 고르지 못한 굴곡과 스크레칭 팁 사이에 직각을 이루는 접촉면에서의 미세한 조절이 가능하도록 하였다. 실험용 팁으로 confluent monolayer위에 스크래치를 내었을 때에는 다양한 지그재그 패턴이 그려진 반면에, 직접 제작한 wound maker에서는 동일한 형태의 선형 wounds가 fibroblast가 seeding된 96-well plate의 각 well의 중심부에 그려짐을 확인하였다. 상용화 되어있는 몇몇 multi-well plate가 본 실험에서 제작된 wound maker와 호환되는 것을 고려하여 보았을 때에, 실시간 wound healing을 관찰하는 high content screening (HCS)실험에 있어서의 활용적인 측면에서 기존의 전형적인 polypropylene 파이펫 팁을 이용한 스크래칭 방법보다 더욱 용이한 방법임을 알 수 있다.

• Archives of Plastic Surgery
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• 제36권6호
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• pp.679-684
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• 2009

Purpose: Human lipoaspirate cells are relatively easy to obtain in large quantities without cell culture. The aim of this in vitro pilot study was to determine the effect of cell therapy using uncultured lipoaspirate cells on cell proliferation and collagen synthesis of diabetic fibroblasts, which are the major contributing factors in wound healing. Methods: In order to get diabetic fibroblasts, dermis tissues were obtained from foot skin of diabetic patients who underwent debridements or toe amputations(n = 4). In order to isolate lipoaspirate cells, the same diabetic patients' abdominal adipose tissues were obtained by liposuction. The diabetic fibroblasts were co - cultured with or without autogenous lipoaspirate cells using porous culture plate insert. Initial numbers of the lipoaspirate cells and diabetic fibroblasts seeded were 15,000 cells/well, respectively. For cell proliferation assay, two treatment groups were included. In group I, diabetic fibroblasts were cultured with the insert having no cells, which serves as a control. In group II, the lipoaspirate cells were added in the culture plate insert. For collagen synthesis assay, one additional group(group III), in which diabetic fibroblasts were not seeded in the well and only lipoaspirate cells inside the insert were incubated without diabetic fibroblasts, was included for a reference. Results: One hundred to one hundred sixty thousand lipoaspirate cells were isolated per ml of aspirated adipose tissue. After 3 - day incubation, the mean cell numbers in group I and II were 17,294/well and 22,163/well. The mean collagen level in group I, II, and III were 29, 41, and 2 ng/ml, respectively. These results imply that both cell proliferation and collagen synthesis in the lipoaspirate cell treatment group were 28 and 44 percents higher than in the control group, respectively(p < 0.05). Conclusion: Uncultured lipoaspirate cell autografts may stimulate the wound healing activity of diabetic fibroblasts.

• 대한한방종양학회지
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• 제6권1호
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• pp.47-65
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• 2000

In order to investigate antitumor and immune response effect by Hyangsapyungwisan after Sarcoma-180 cells and methotrexate were treatred each other, the extract of Hyangsapyungwisan was orally administered to ICR mice for 14 days. To evaluate the effects of the Hyangsapyungwisan, 50% inhibition concentration($IC_{50}$), mean survival days, tumor weight for antitumor effects, hemagglutinin titer, hemolysin titer, rosette forming cells, natural killer cell activity and productivity of interleukin-2 for immune responses measured in ICR mice. The results were summarized as follows: 1. Mean survival time in Hyangsapyungwisan-treated group was slightly prolonged, as compared with control group(13.46%). 2. On the MTT assay, cell viability was significantly inhibited by $5{\mu}g/well,\;2.5{\mu}g/well,\;1.25{\mu}g/well,\;and\;0.625{\mu}g/well$ of Hyangsapyung-wisan concentration inhibited cell viability significantly. $IC_{50}$ for cell viability was $11.59{\mu}g/well$. 3. Tumor weight in Hyangsapyungwisan treated group was depressed, as compared with the control group(p<0.05). 4. Hemagglutinin titer in Hyangsapyungwisan-treated group was slightly increased with no significance, as compared with the control group. 5. Hemolysin titer in Hyangsapyungwisan-treated group was silightly increased, as compared with the control group(p<0.05). 6. Rosette forming cells in Hyangsapyungwisan-treated group was silightly increased, as compared with the control group(p<0.05). 7. Naural killer cell activity in Hyangsapyungwisan-treated group was significantly increased(p<0.05). 8. Production of interleukin-2 was significantly increased(p<0.05). According to the above results, Hyangsapygwisan had prominent antitumor effects, and enhance both cellular and humoral immunity in mice.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2457-2460
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• 2003

There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology. The cell rotator consists of injection hole and rotation well to rotate a biological cell properly. Under the variation of flow rate in injection hole, the angular velocity of a biological cell is evaluated to find the feasibility of the proposed rotation method. As a practical experiment, Zebrafish egg is employed. Based on this research, we find the possibility of non-contact rotation way that can highly reduce the damage of the biological cell during manipulation. To realize an autonomous biological cell manipulation, a cell chip with manipulation well and micro channel in this research will be utilized effectively in near future.

• 한국동물생명공학회지
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• 제39권1호
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• pp.19-30
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• 2024

Background: Although an understanding of the proliferation and differentiation of fish female germline stem cells (GSCs) is very important, an appropriate threedimensional (3D) research model to study them is not well established. As a part of the development of stable 3D culture system for fish female GSCs, we conducted this study to establish a 3D aggregate culture system of ovarian cells in marine medaka, Oryzias dancena. Methods: Ovarian cells were separated by Percoll density gradient centrifugation and two different cell populations were cultured in suspension to form ovarian cell aggregates to find suitable cell populations for its formation. Ovarian cell aggregates formed from different cell populations were evaluated by histology and gene expression analyses. To evaluate the media supplements, ovarian cell aggregate culture was performed under different media conditions, and the morphology, viability, size, gene expression, histology, and E2 secretion of ovarian cell aggregates were analyzed. Results: Ovarian cell aggregates were able to be formed well under specific culture conditions that used ultra-low attachment 96 well plate, complete mESM2, and the cell populations from top to 50% layers after separation of ovarian cells. Moreover, they were able to maintain minimal ovarian function such as germ cell maintenance and E2 synthesis for a short period. Conclusions: We established basic conditions for the culture of O. dancena ovarian cell aggregates. Additional efforts will be required to further optimize the culture conditions so that the ovarian cell aggregates can retain the improved ovarian functions for a longer period of time.

• Archives of Pharmacal Research
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• 제20권6호
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• pp.566-571
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• 1997

To gain further insight into how estrogens modulate cell function, the effects of estrogen on cell proliferation were studied inhuman breast cancer cells. We examined the effects of estrogen on the proliferation of three human breast cancer cell lines that differed in their estrogen receptor contents. Ten nM estradiol markedly stimulated the proliferation of MCF-7 human breast cancer cells that contained high levels of estrogen receptor $1.15{\pm}0.03 pmole/mg protein)$(over that of control. In T47D cells that contained low levels of estrogen receptor $0.23{\pm}0.05 pmole/mg protein)$, Ten nM estrogen slightly stimulated the proliferation over that of control. MDA-MB-231 cells, that contained no detectable levels of estrogen receptors, had their growth unaffected by estrogen. These results showed their sensitivity to growth stimulation by estrogen correlated well with their estrogen receptor content. Also we examined the effect of estrogen on cellular progesterone receptor level as well as plasminogen activator activity in MCF-7 cells. Ten nM estradiol showed maximal stimulation of progesterone receptor level as well as plasminogen activator activity in MCF-7 cells. It is not clear whether these stimulations of progesterone receptor and plasminogen activator activity by estrogen are related to the estrogen stimulation of cell proliferation of MCF-7 cells. Studies with estrogen in human breast cancer cells in culture indicate that sensitivity to growth stimulation by estrogen correlates well with estrogen receptor contents.

• Journal of Oral Medicine and Pain
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• 제18권2호
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• pp.97-106
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• 1993

This study was performed to investigate the effects of infrared and visible light laser irradiation on cell viability of human gingival fibroblast. For the present study, the author used cultured fibroblast originated from sound gingiva which were fifth of sixth passage. Laser machine utilized here were stomalaser which irradiate infrared (GaAs diode) and red (HeNe) laser in turn with pulse wave pattern or continuous wave pattern, and the machine had several frequency mode presented by regeneration, relaxation and analgesic modalities. Cultured fibroblast samples were divided by this modalities of cell counts and laser exposure time which were 7-seconds of 150 seconds, respectively. 1 day after laser irradiation, each cell-well was treated with MTT and measured optical density with ELISA. The obtained results were as follows : 1. There was a tendency of increasing optical density in proportion to irradiation time in groups of $1\times10^4$ cell per well but in groups of $5\times10^3$ cell per well, reverse phenomena were observed. 2. The difference of optical density according to frequency modalities were not showed significantly except several cases in groups of $5\times10^3$ cell per well. 3. In general, cell viability of cultured human gingival fibroblast wer not showed consistent feature by low level laser irradiation.

• 통합자연과학논문집
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• 제9권3호
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• pp.171-176
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• 2016

Rap1 is a key regulator of cell adhesion and migration. Although increasing evidence indicates that the Rap1 signaling pathway is involved in the process of bone remodeling, the mechanism by which Rap1 regulates osteoblastic differentiation and cell adhesion remains unknown. Here, we investigated the morphological characteristics and osteoblastic differentiation of cells expressing constitutively activated form of Rap1A (Rap1ACA) or Rap1 GTPase activating protein Rap1GAP and found that activated Rap1 induces osteoblastic differentiation and cell adhesion as well as cell spreading. When osteoblastic differentiation was induced, Rap1ACA cells showed considerably higher levels of calcium deposits than the wild-type and Rap1GAP-overexpressing cells did. Rap1ACA cells showed increased spreading and size, as well as strong cell adhesion and significantly decreased growth rates. F-actin staining using phalloidin revealed several thin thread-like filopodia around the protrusions in Rap1ACA cells, which possibly contribute to the increased cell adhesion.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1284-1288
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• 2021

In this work, we propose and design a GaN-based diode with a p-doped GaN (p-GaN) multi-well structure for high efficiency betavoltaic (BV) cells. The short-circuit current density (J_SC) and opencircuit voltage (V_OC) of the devices were investigated with variations of parameters such as the doping concentration, height, width of the p-GaN well region, well-to-well gap, and number of well regions. The J_SC of the device was significantly improved by a wider depletion area, which was obtained by applying the multi-well structure. The optimized device achieved a higher output power density by 8.6% than that of the conventional diode due to the enhancement of J_SC. The proposed device structure showed a high potential for a high efficiency BV cell candidate.