• 한국결정성장학회지
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• 제30권5호
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• pp.163-167
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• 2020

본 연구에서는 PVT(Physical Vapor Transport) 방법을 이용하여 반도체 식각 공정용 소재로 사용되는 링 모양의 SiC(Silicon carbide) 다결정을 제조하였다. 흑연 도가니 내부에 원기둥 모양의 흑연 구조물을 배치하여 PVT법에 의한 링 모양의 SiC 다결정을 성장시켰다. 성장된 결정은 Raman 및 UVF(Ultra Violet Fluorescence) 분석을 이용하여 결정의 상분석을 하였고, SEM(Scanning Electron Microscope), EDS(Energy Dispersive Spectroscopy) 분석을 통해 미세조직 및 성분을 확인하였다. PVT 성장 초기의 온도변화를 통하여 SiC 다결정의 결정립 크기와 성장 속도를 조절할 수 있었다.

• 한국진공학회지
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• 제10권2호
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• pp.267-274
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• 2001

원격 수소 플라즈마에 의한 Si 웨이퍼 표면 위의 Cr, Ni 및 Cu불순물의 제거 효과를 조사하였다. Si 웨이퍼를 이 불순물들이 포함되어 있는 아세톤으로 집중적으로 오염시켰으며 최적 공정조건을 결정하기 위해 rf-power와 plasma노출시간을 변화시키면서 실험을 수행하였다. 리모트 수소 플라즈마 세정 후 Si 웨이퍼 표면은 Total X-ray Reflection Fluorescence(TXRF), Surface Photovoltage(SPV) 및 Atomic Forece Microscope(AFM)에 의해 분석되었다. 리모트 수소 플라즈마 세정 후 Cr, Ni 및 Cu불순물의 농도는 감소하였고 소수 전하운반자수명은 전반적으로 증가하였다. 또한 AFM 분석결과 표면 거칠기는 전반적으로 향상되었고 Si 기판에 거의 손상을 주지 않았다. TXRF 분석결과는 리모트 수소 플라즈마 세정이 적절한 공정 조건에서 이루어질 때 금속 오염물의 제거에 아주 효과적임을 보여주었다. 또한, Cr, Ni 및 Cu 불순물의 제거는 $SiO_2$가 제거될 때 $SiO_2$에 묻어 함께 제거되는 이른바 lift-off mechanism에 의한 것으로 사료된다.

• 대한한방내과학회지
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• 제21권4호
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• pp.621-631
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• 2000

Objective : In this study, the medicine herbs above were directly treated to cultured normal lung cells and lung carcinoma cells, and the effects were investigated to develope new cancer treatments with increased anti-cancer efficiency as well as decreased side-effects and to suggest more useful clinical therapies. Materials and Methods : In the experiment, WI-26 VA lung normal cell line and A-427 lung carcinoma cell line were cultured. To observe the morphological change of the treated cells, were subjected to Giemsa staining and observed under Reflected Fluorescence microscope. To examine whether cell death occurred, cells observed under Reflected Fluorescence microscope, To investigate the degree of cell death in the nucleus, cells were screened by Laser cytometry ACAS 570. Results : Samgibopye-tang(Shenqibufei-tang) stimulated not only the growth of the normal cells but also that of the carcinoma cells, Wikyeung-tang(Weijing-tang) induced morphological change such as cytoplasmic constriction in the normal cells and the carcinoma cells, but it did not show any strong inhibitory effect on the cell growth. Samso-eum(Shensu-yin) caused severe cell damage in both cell lines, Eunkyo San(Yinqiao-san) significantly damaged the nuclei and caused weak cytoplasmic constriction in both cell lines, Normal cells treated with Gilgyeung-tang(Jingeng-tang) did not show any significant morphological change while some Gilgyeung-tang(Jingeng-tang) treated carcinoma cells were observed to have a normal cell-like shape, interestingly, conclusions : As the results above, Samgibopye-tang(Shenqibufei-tang), Wikyeung-tang(Weijing-tang), and Gilgyeung-tang(Jingeng-tang) helped the growth of both cell lines, and especially Samgibopye-tang(Shenqibufei-tang) showed the best effect, However, Samso-eum(Shensuyin) and Eunkyo-san(Yinqiao-san) caused lethal damage in the normal cells and also showed strong toxicity in the carcinoma cells.

• Archives of Plastic Surgery
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• 제36권2호
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• pp.135-139
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• 2009

Purpose: The use of an autogenous fat graft has become a common procedure in plastic surgery. However, questions remain concerning on the viability of fat cells and preservation method of aspirated fat. The purpose of this study was to examine the viability of fat cells stored at $-20^{\circ}C$ in the freeze for 1 year after harvest from abdominal liposuction. Methods: Eighteen adults (aged 24 to 65 years old, 16 female and 2 male) were recruited for this study. Harvested aspirated fat tissues were obtained by suction - assisted lipectomy and frozen at $-20^{\circ}C$ commercial refrigerator for one year (average 12.5 months). The viability off at cells in specimens were measured after thawing. The numbers of viable cells were measured on a fluorescence microscope after staining with fluorescein diacetate and propidium iodide. GPDH (Glycerol - 3 - phosphate dehydrogenase) activity was measured. Cell culture was done for 3 weeks. Results: There were no viable cells under the fluorescence microscope, no detectable GPDH activity, and no cultured cells. Conclusion: These findings suggest that aspirated fat after frozen storage for one year at $-20^{\circ}C$ freezer is inadequate to reuse.

• Clinical and Experimental Reproductive Medicine
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• 제22권3호
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• pp.279-285
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• 1995

Despite the frequent incidence of embryo fragmentation in early human embryos, the reason of the embryo fragmentation has not been known yet. This study was conducted to investigate the histological difference(s) between fragmented (FR) and non-fragmented (NFR) human embryos focusing on comparison of mitochondrial distribution and protein synthesis. Multi-pronuclei zygotes (MPZ) such as three or more pronuclei containing in human in vitro fertilization and embryo transfer (IVF-ET) program were used for this study. MPZ were cultured in TCM-199 supplemented with 10% of human fetal cord serum (hFCS) in 5% $CO_2$ incubator at $37^{\circ}C$ for 24 hours. The cleaved embryos to 2-4 cells after 24 hours were grouped by their grade of fragmentation. Embryos were stained with Rhodamine123 (Rh123) and fluorescence was evaluated under the fluorescence microscope through PB 450-490 filter (Leitz). Regarding to protein synthesis during early human embryogenesis, there is no significant difference in the amount of synthetic proteins between FR and NFR embryos. Distribution of cytoplasmic organelles in embryos was evaluated by transmission electron microscope (TEM). The cytoplasmic distribution of mitochondria was different between FR and NFR embryos. The mitochondrial distribution was even in NFR, whereas severely aggregated in FR. It is not able to clarify in the present study whether this uneven mitochondrial distribution in FR embryo is the reason for embryo fragmentation or is the result from fragmentation. Physiological disparity related to the mitochondrial distribution may be one of the reasons for embryo fragmentation. Further studies should be addressed to investigate the physiological differences between FR and NFR embryos.

• 한국재료학회지
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• 제33권9호
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• pp.367-371
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• 2023

In this study we examine variations in the structure of perovskite compounds of LaBa₂Cu₂O₉, LaBa2₂CaCu₃O₁₂ and LaBa₂Ca₂Cu₅O₁₅ synthesized using the solid state reaction method. The samples' compositions were assessed using X-ray fluorescence (XRF) analysis. The La: Ba: Ca: Cu ratios for samples LaBa₂Cu₂O₉, LaBa2₂CaCu₃O₁₂ and LaBa₂Ca₂Cu₅O₁₅ were found by XRF analysis to be around 1:2:0:2, 1:2:1:3, and 1:2:2:5, respectively. The samples' well-known structures were then analyzed using X-ray diffraction. The three samples largely consist of phases 1202, 1213, and 1225, with a trace quantity of an unknown secondary phase, based on the intensities and locations of the diffraction peaks. According to the measured parameters a, b, and c, every sample has a tetragonal symmetry structure. Each sample's mass density was observed to alter as the lead oxide content rose. Scanning electron microscope (SEM) images of the three phases revealed that different Ca-O and Cu-O layers can cause different grain sizes, characterized by elongated thin grains, without a preferred orientation.

• 치위생과학회지
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• 제23권4호
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• pp.369-377
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• 2023

Background: In this study, we investigated the potential use of keratin for oral tissue regeneration. Keratin is well-known for its effectiveness in skin regeneration by promoting keratinization and enhancing the elasticity and activity of fibroblasts. Because of its structural stability, high storability, biocompatibility, and safety in humans, existing research has predominantly focused on its role in skin wound healing. Herein, we propose using keratin proteins as biocompatible materials for dental applications. Methods: To assess the suitability of alpha-keratin protein as a substrate for cell culture, keratin was extracted from human hair via PEGylation. Viabilities of primary human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs) were assessed. Fluorescence immunostaining and migration assays were conducted using a fluorescence microscope and confocal laser scanning microscope. Wound healing and migration assays were performed using automated software to analyze the experimental readout and gap closure rate. Results: We confirmed the extraction of alpha-keratin and formation of the PEG-g-keratin complex. Treatment of HGFs with keratin protein at a concentration of 5 mg/ml promoted proliferation and maintained cell viability in the test group compared to the control group. HOKs treated with 5 mg/ml keratin exhibited a slight decrease in cell proliferation and activity after 48 hours compared to the untreated group, followed by an increase after 72 hours. Wound healing and migration assays revealed rapid closure of the area covered by HOKs over time following keratin treatment. Additionally, HOKs exhibited changes in cell morphology and increased the expression of the mesenchymal marker vimentin. Conclusion: Our study demonstrated the potential of hair keratin for soft tissue regeneration, with potential future applications in clinical settings for wound healing.

• 대한약침학회지
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• 제8권3호
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• pp.5-9
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• 2005

미분간섭현미경법과 아크리딘-오렌지(acridine-orange) 형광 염색을 이용하여 쥐 혈관 내의 실 모양 구조물을 관찰하였다. 공초점현미경법과 헤마톡실린-에오신(hematoxylin-eosin) 염색을 통해 피브린, 모세혈관, 소정맥, 소동맥 혹은 림프관의 핵 분포와 뚜렷이 구별되는 혈관 내 실 모양 구조물의 핵 분포 패턴을 얻어낼 수 있었다. 이 실 모양 구조물의 생리적 기능을 침술과 연관하여 논의하였다. 특히, 이 실 모양 관을 통한 약물의 흐름이 약침의 기전에 해당할 것이라는 가설을 제기하였다.

• 한국컴퓨터그래픽스학회논문지
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• 제23권4호
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• pp.31-40
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• 2017

최근 3차원 세포 배양이 가능해 지면서 세포의 부피, 3차원 형태 등을 보다 정확하게 확인할 수 있게 되었다. 일반적으로 세포의 3차원 단층 정보는 공초점 현미경 또는 전자 현미경과 같은 특수한 현미경을 이용하여 관찰 해야 한다. 그러나 공초점 현미경은 일반 현미경에 비해 비용이 비싸며, 촬영 시간이 오래 걸린다. 따라서 일반적으로 사용되는 광학 현미경으로 세포의 3차원 형태복원을 하는 방법이 필요하다. 본 논문에서는 다초점 형광 영상을 기반으로 영상의 추정된 초점 값(focus estimator value)을 이용해 세포를 3차원으로 형태 복원하는 방법을 제안한다. 먼저 3차원으로 배양된 세포를 광학 현미경으로 초점을 변경 하면서 다초점 영상들을 촬영한다. 이후 영상에서 circular Hough transform을 이용하여 세포 군집의 대략적인 위치를 ROI(Region Of Interest)로 정한다. 획득한 ROI에 MSBF(Modified Sliding Band Filter)를 적용하여 ROI 내에 세포 군집의 외곽선을 추출하고, 추출된 외곽선을 기준으로 추정 초점 값을 구한다. 계산된 초점 값과 현미경의 NA(Numerical Aperture)을 이용하여 깊이를 고려한 세포 군집의 외곽선을 추출하고 추출된 외곽선을 통해 세포들을 3차원으로 형태 복원한다. 복원 결과는 세포 영상의 in-focus가 된 부분들을 하나로 합친 영상과 비교하여 검증한다.

• 한국수정란이식학회지
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• 제14권1호
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• pp.1-8
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• 1999

The efficiency of transgenic livestock animal production may be improved by early selection of transgenci preimplantation embryos. To examine the possibility of GFP gene as a non-invasive marker for the early screening of transgenic embryo, the GFP gene was microinjected into rabbit zygotes and the later stages of preimplantation embryos were examined for the expression of GFP. The presence of injected DNA was detected by PCR analysis and the expression of GFP was detected by observing green fluorescence in embryos under a fluorescent microscope. Out of 108 GFP gene-injected rabbit zygotes, seventy three(67.6%) were fluorescence-positive. When 11 fluroresecence-positive blastocysts were analyzed for the presence of GFP gene by PCR, 6(54.5%) were positive, and all of the 8 flrouescence-negative blastocysts were also negative by PCR. The results indicate that the screening of transgene in rabbit embryos by PCR analysis and GFP detection could be a promising method for the preselection of transgenic embryos.