• 대한의용생체공학회:의공학회지
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• 제16권1호
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• pp.1-8
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• 1995

A variety of experiments of endothelial cell seeding onto artificial vessels have been performed. To improve endothelialization, one or two components of the extracellular matrix (ECM) have been used as an underlying matrix. In this study, the whole ECM excreted from fibroblasts was used as an underlying matrix. Fetal human fibroblasts were cultured on a polyurethane (PU) sheet. After a conflu; ence was attained, the cytoskeleton and the nuclei of the fibroblast were destroyed using Triton-X. Mitomycin, or irradiation. Omental microvascular endothelial cells from adult human were seeded onto various substrates. After 12 days in culture, the cells were counted. It was observed that the ECM treated by irradiation had the highest cell number. In addition, the cells on this substrate exhibited the most typical endothelial cell morphology. For preliminary animal experiments the PU vessels (inner diameter, 1.5mm) coated with ECM were implanted in the infrarena] abdominal aorta of rat. After the vessels had been implanted for 5 weeks, it was found that the surface of the PU vessels was completely covered with endothelia] cells. In conclusion, we can state that the fibroblast-derived whole ECM makes a better underlying substrate for the endothelialization of small diameter artificial vessels.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1032-1037
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• 2017

The poly-${\gamma}$-$\small{D}$-glutamic acid (PGA) capsule, a major virulence factor of Bacillus anthracis, provides protection of the bacterium from phagocytosis and allows its unimpeded growth in the host. We investigated crosstalk between murine natural killer (NK) cells and macrophages stimulated with the PGA capsule of Bacillus licheniformis, a surrogate of the B. anthracis capsule. PGA induced interferon-gamma production from NK cells cultured with macrophages. This effect was dependent on macrophage-derived IL-12 and cell-cell contact interaction with macrophages through NK cell receptor NKG2D and its ligand RAE-1. The results showed that PGA could enhance NK cell activation by inducing IL-12 production in macrophages and a contact-dependent crosstalk with macrophages.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.276-276
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• 2012

The interface morphology of organic active layers is known to play a crucial role in the performance of organic photovoltaic (OPV) cells. Especially, a controlled nanostructure with a large contact area between electron donor (D) and acceptor (A) layers is necessary to improve the power conversion efficiency (PCE) of the cells since the short exciton diffusion lengths in organic semiconductors limit the charge (hole and electron) separation before excitons recombination. In this work, we developed simple solvent treating methods to fabricate a nanostructured DA interface and applied them to enhance the PCE of ZnPc/C60 based small molecule OPV cells. Interestingly, it was observed that the solvent treatment on the donor layer prior to the deposition of the acceptor layer resulted in a significant decrease in PCE, which was due to an existence of undesirable voids at the DA interface. Instead, the solvent vapor treatment after the DA bilayer formation led to densely packed and well dispersed DA contacts. Consequently, 3-fold enhancement of PCE as compared to the untreated bilayer cell was accomplished.

• 대한세포병리학회지
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• 제19권2호
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• pp.206-208
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• 2008

Adenocarcinomas with micropapillary patterns are generally aggressive and show lymphotropism. Only a few reports on pulmonary adenocarcinoma with micropapillary patterns have described cytologic findings. A 70-year-old Korean woman was admitted to the hospital because of intermittent dry cough and chest pain. Cytology after bronchial washing showed neoplastic cells in small, angulated, cohesive clusters consisting of 3-20 cells without a fibrovascular core. The resected right middle lobe showed a tumor occupying almost the entire lobe. Histologically, about 90% of neoplastic cells proliferated with micro papillary morphology in the background of bronchioloalveolar carcinoma. Cytologic smears of a bronchial washing showing tumor cells in small, cohesive clusters without a fibrovascular core may indicate an adenocarcinoma with micropapillary pattern.

• 대한수의학회지
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• 제33권4호
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• pp.591-596
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• 1993

The smear preparations of the semen from Korean native bull and the tissue preparations of the organs from male and female mice were performed by fluorescent staining method. More than 600 spermatozoa per straw from two semen straw groups and more than 300 cells per mouse organ from two mice per sex were observed and then the ratio of spermatozoa bearing B-body and the cells bearing F-body were assessed, respectively. 1. The ratios of spermatozoa bearing B-body in semen of Korean native bull were $37.3{\pm}3.1%$. 2. The ratios of cells bearing F-body in the organs of mice were $63.5{\pm}4.5%$ in male tissues and $7.5{\pm}3.2%$ in female tissues. 3. The organs with higher appearance frequency of F-body were ordered as brain, kidney, stomach, lung, testis, liver, small intestine, spleen and pancreas in male mice and pancreas, small intestine, liver, brain, kidney, lung, spleen and stomach in female mice.

• IMMUNE NETWORK
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• 제16권3호
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• pp.183-188
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• 2016

Sirtuin family members with lysine deacetylase activity are known to play an important role in anti-aging and longevity. Cellular senescence is one of the hallmarks of aging, and downregulation of sirtuin is reported to induce premature senescence. In this study, we investigated the effects of small-molecule sirtuin inhibitors on cellular senescence. Various small molecules such as tenovin-1 and EX527 were employed for direct sirtuin activity inhibition. U251, SNB-75, and U87MG glioblastoma cells treated with sirtuin inhibitors exhibited phenotypes with nuclear enlargement. Furthermore, treatment of rat primary astrocytes with tenovin-1 also increased the size of the nucleus. The activity of senescence-associated β-galactosidase, a marker of cellular senescence, was induced by tenovin-1 and EX527 treatment in U87MG glioblastoma cells. Consistent with the senescent phenotype, treatment with tenovin-1 increased p53 expression in U87MG cells. This study demonstrated the senescence-inducing effect of sirtuin inhibitors, which are potentially useful tools for senescence research.

• ALGAE
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• 제20권4호
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• pp.315-324
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• 2005

Anatomical organization of Stoechospermum marginatum reveals small cortical cells with moderately dense cytoplasm, overlying a multilayered medulla comparatively poor in cytoplasmic contents. The anticlinal walls of cortical cells show local thickenings rich in alginic acids. Sori form on both thallus surfaces and show tetrasporangia, paraphyses and sterile-cells. The unicellular paraphyses are rich in sulphated polysaccharides whereas multicellular ones have abundance of not only polysaccharides, but also of vacuoles and phenols. The sterile-cells are modified cortical cells present on either side of the tetrasporangium and bear cytoplasmic strands towards soral cavity. Various stages of tetrasporogenesis are seen in a single sorus. The developing tetrasporangium shows a two layered wall, where the outer one is rich in alginic acid and inner has sulphated polysaccharides. An apical pad aids tetraspore release. Also involved in the release process are sterile-cells, paraphyses and polysaccharides.

• Applied Microscopy
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• 제11권1호
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• pp.1-9
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• 1981

The study on the nerve cells in the subesophageal ganglion of 5-day-old cabbage butterfly, Pieris rapae L., was performed to observe their ultrastructures and classify them on the basis of the differences in size, shape and relative distribution of cell organelles. 1. Type I neurons: These cells are neurosecretory granules ranging 100 to 300 nm in size. 2. Type II neurons: As giant neurons averaging 25 to $30{\mu}m$ in size, such as mitochondria and Golgi apparatus. 3. Type III neurons: These spindle-shaped cells range 9 to $15{\mu}m$ in width. 4. Type IV neurons: These cells have a range of diameter from 12 to $16 {\mu}m$. The cells are abundantly observed in the subesophageal ganglion. 5. Type V neurons: These cells are very small nerve cells with 4.5 to $8.0{\mu}m$ in size and have a prominent nucleus.

• 대한세포병리학회지
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• 제18권2호
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• pp.170-174
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• 2007

Granular cell tumor is a rare tumor of the soft tissue and this is characterized by proliferation of large cells with granular appearing eosinophilic cytoplasm. We report the imprint cytologic features of a case of granular cell tumor in the left calf of a 52-year-old woman. Microscopic examination showed moderate cellularity. The tumor cells were arranged both as single cells and in clusters. The cells were large polygonal-shaped and they had small round nuclei with finely granular chromatin and occasionally conspicuous nucleoli. The cytoplasm was abundant eosinophilic and granular. Naked nuclei and spindle-shaped tumor cells were occasionally noted. No mitosis and necrosis were present. The background showed cytoplasmic granular materials. The tumor cells showed positivity for S-100 protein. Ultrastructurally, abundant lysosomes were present in the cytoplasm of the tumor cells.

• 전자공학회논문지
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• 제53권5호
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• pp.13-18
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• 2016

LTE-A(Long Term Evolution-Advanced)에서는 비용 효율적 방법으로 급증하는 무선 데이터 서비스를 대처하고 사용자의 QoS(Quality of Service)를 만족시키기 위해 SCE(Small Cell Enhancement)에 대한 연구가 활발히 진행되고 있다. 하지만 수많은 소형셀이 밀집하여 불규칙하게 배치되기 때문에 전송품질 저하 등 많은 문제가 발생하게 된다. 본 논문에서는 밀집한 소형셀 네트워크에서 클러스터링 기반 간섭 관리 기법을 제안한다. 제안 기법은 UE(User Equipment)로부터 받은 RSRP(Reference Signal Received Power)를 비교하여 소형셀의 클러스터를 구성한다. 클러스터 내에서 ABS를 적용하여 소형셀 간 간섭을 완화시킨다. 또한, 전력제어를 적용하여 클러스터 간 간섭을 줄인다. 모의실험 결과, 제안한 기법에서 소형셀 사용자의 SINR(Signal to Interference plus Noise Ratio), 전송률 및 스펙트럼 효율이 향상되어 전체적인 셀 성능이 향상 되는 것을 볼 수 있다.