• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1993년도 제27차 학술대회 초록집
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• pp.98-98
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• 1993

편도선의 염증반응은 세균이 편도상피세포에 부착되는 것으로부터 시작되며 부착된 세균은 증식하여 집락을 형성한 후 독소를 분비하여 점막 장벽을 뚫고 조직에 손상을 일으킨다. 저자들은 급성편도선염의 병태를 이해하기 위하여 생체내에서 급성편도선염 환자군과 정상인에서 상피세포의 세균부착성에 대한 차이를 알아보고자 본 실험을 시행하였다. 급욍편도선염 환자군 20례와 정상인 대조군 20례를 대상으로 편도선부위를 면봉으로 문지른후 세포혼합물을 Acridine orange로 염색하여 형광현미경하에서 관찰하였다. 50개의 편도상피세포에서 부착된 세균수를 계산하였다. 또한 동시에 근배양을 시행하였다. 급성편도선염군은 대조군보다 상피세포에서 10% 이상 부착된 세균수가 많았으며 (p<0.05), 상피세포에 부착된 세균수는 연령과 유의한 상관관계를 보여주었다.

• 대한소아치과학회지
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• 제32권3호
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• pp.395-402
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• 2005

손상 받은 치주 조직의 치유과정은 치주인대 섬유 모세포의 세포 활성도에 영향을 받는다. 또한 치유과정 중 치주인대 섬유 모세포간의 재부착이 이루어져야 한다. 본 연구의 목적은 표피성장인자가 치주인대 세포의 증식과 부착에 미치는 영향을 알아보는 것으로 이를 바탕으로 향후 완전 탈구된 치아의 보관용액이나 재식전 처리제로서의 표피성장인자의 효용성을 고찰해 보기 위함이다. 발치된 사람의 제 1소구치에서 치주인대 섬유모세포를 채취 및 배양한 후, 세포독성을 및 세포의 최고 활성도를 평가 하기 위해 MTT assay를 시행하였다. 표피성장인자가 첨가된 실험군과 대조군의 세포증식의 차이를 비교하였고, western blot을 통해서 세포 부착에 관여하는 섬유결합소의 발현을 실험군과 대조군을 통해 비교하여 다음의 결과를 얻었다. 표피성장인자는 치주인대 섬유모세포에 대하여 세포독성을 보이지 않으며, 최고의 활성도를 보이는 농도는 10ng/ml였다. 또한 치주인대 섬유모세포의 배지내 증식정도는 10ng/ml의 실험군에서 대조군에 비해 유의하게 높았다. 세포간 부착에 관여하는 섬유결합소의 발현율이 실험군에서 대조군에 비해 유의하게 증가하였다. 본 연구를 통해 표피성장인자는 치주인대 섬유모세포의 재생을 촉진하며 따라서 완전 탈구된 치아의 보관용액이나 재식전 처리제로 사용될 수 있음을 시사한다.

• 한국통신학회논문지
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• 제27권2C호
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• pp.123-130
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• 2002

셀룰러 망 환경에서 인터넷 호스트의 이동성을 지원하기 위하여, 본 논문에서는 Mobile IP의 단점을 보완할 수 있는 적응적 이동성 제어 방식과 이러한 방식을 구현하기 위한 프로토콜을 제안한다. 본 논문에서 제안한 방식은 사용자의 이동성에 따라 외부 에이전트의 의탁주소를 적응적으로 결정한다. 따라서, 제안된 방식은 외부 도메인의 게이트웨이를 외부 에이전트로 지정하는 기존의 마이크로 이동성 지원 방안들과는 다르다. 이렇게 적응적 방식을 사용하면, 셀룰러 망에서 다양한 환경에 적합한 서비스 품질을 사용자들에게 효과적으로 제공할 수 있다. 또한 핸드오버를 자주 하여 발생하는 Mobile IP의 신호 부하도 줄일 수 있다. 제안된 방식의 성능을 시뮬레이션을 통하여 검토해 본 결과, 이동 노드에게 비교적 안정된 접속점을 제공할 수 있음을 알 수 있었다.

• Molecules and Cells
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• 제43권4호
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• pp.313-322
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• 2020

Eukaryotes transport biomolecules between intracellular organelles and between cells and the environment via vesicle trafficking. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE proteins) play pivotal roles in vesicle and membrane trafficking. These proteins are categorized as Qa, Qb, Qc, and R SNAREs and form a complex that induces vesicle fusion for targeting of vesicle cargos. As the core components of the SNARE complex, the SNAP25 Qbc SNAREs perform various functions related to cellular homeostasis. The Arabidopsis thaliana SNAP25 homolog AtSNAP33 interacts with Qa and R SNAREs and plays a key role in cytokinesis and in triggering innate immune responses. However, other Arabidopsis SNAP25 homologs, such as AtSNAP29 and AtSNAP30, are not well studied; this includes their localization, interactions, structures, and functions. Here, we discuss three biological functions of plant SNAP25 orthologs in the context of AtSNAP33 and highlight recent findings on SNAP25 orthologs in various plants. We propose future directions for determining the roles of the less well-characterized AtSNAP29 and AtSNAP30 proteins.

• BMB Reports
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• 제53권4호
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• pp.173-180
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• 2020

Galectin-3 is a carbohydrate-binding protein and regulates diverse functions, including cell proliferation and differentiation, mRNA splicing, apoptosis induction, immune surveillance and inflammation, cell adhesion, angiogenesis, and cancer-cell metastasis. Galectin-3 is also recommended as a diagnostic or prognostic biomarker of various diseases, including heart disease, kidney disease, and cancer. Galectin-3 exists as a cytosol, is secreted in extracellular spaces on cells, and is also detected in nuclei. It has been found that galectin-3 has different functions in cellular localization: (i) Extracellular galectin-3 mediates cell attachment and detachment. (ii) cytosolic galectin-3 regulates cell survival by blocking the intrinsic apoptotic pathway, and (iii) nuclear galectin-3 supports the ability of the transcriptional factor for target gene expression. In this review, we focused on the role of galectin-3 on translocation from cytosol to nucleus, because it happens in a way independent of carbohydrate recognition and accelerates cancer progression. We also suggested here that intracellular galecin-3 could be a potent therapeutic target in cancer therapy.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.134.1-134.1
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• 2017

In this study, we propose a new scaffold fabrication method, "direct electro-hydrodynamic jet process," using the initial jet of an electrospinning process and ethanol media as a target. The fabricated threedimensional (3D) fibrous structure was configured with multilayered microsized struts consisting of randomly entangled micro/nanofibrous architecture, similar to that of native extracellular matrixes. The fabrication of the structure was highly dependent on various processing parameters, such as the surface tension of the target media, and the flow rate and weight fraction of the polymer solution. As a tissue regenerative material, the 3D fibrous scaffold was cultured with preosteoblasts to observe the initial cellular activities in comparison with a solid-freeform fabricated 3D scaffold sharing a similar structural geometry. The cell-culture results showed that the newly developed scaffold provided outstanding microcellular environmental conditions to the seeded cells (about 3.5-fold better initial cell attachment and 2.1-fold better cell proliferation).

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.176-187
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• 1996

The ability of fibroblasts attached to teeth is paramount important in reestablishing the lost connective tissue attachment after periodontal therapy. The migration and proliferation of periodontal ligament cells are desired goal of periodontal regeneration therapy. PDGF is well known to regulate the cell activity of mesenchymal origin cell. Tobacco contains a complex mixture of substance including nicotine, various nitrosamines, trace elements, and variety of poorly characterized substances. Human gingival fibroblasts and periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Cultured human gingival fibroblasts and periodontal ligament cells in vitro were treated with PDGF, nicotine in time dependent manner. Cellular activities were determined by MTT assay. The purpose of this study was to determine the effects of Nicotine and PDGF, respectively and the effect of PDGF presence of nicotine on human gingival fibroblasts and periodontal ligament cells. The results were as follows : 1. In the cell activities of human gingival fibroblasts and periodontal ligament cells were similar or decreased to control value at 1st day. At 2nd day, cellular activities of both group were increased to control value. At 3rd day, cellular activities of both group were returned to the control value. 2. In the cell activities of PDGF on human gingival fibroblasts and periodontal ligament cells, cell activities significantly increase from control group on periodontal ligament cells compared to gingival fibroblast group at 3rd day. 3. In the cell activities of PDGF and nicotine combined application on human gingival fibroblasts and periodontal ligament cells, it seems likely that the nicotinic effect of gingival fibroblasts were higher than periodontal ligament cells and the PDGF effect of periodontal ligament cells were higher than gingival fibroblasts. This results suggested that PDGF might stimulate the selective growth on periodontal ligament cells.

• 한국전자파학회논문지
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• 제14권8호
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• pp.884-890
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• 2003

본 논문은 휴대폰 전자파에 노출된 항부에서 SAR 값을 저감하기 위하여 전자파 흡수체를 단말기 표면에 부착하여 해석 및 측정하였다. 개발된 전자파 흡수체는 Mn-Zn계로 구성되었으며, 유전율은 7.30-j0.05 이고, 투자율은 2.20-j1.55이다 전자파 흡수체 부착에 의한 SAR 값은 비선형 FDTD 알고리즘을 적용하여 계산하였으며, 동작주파수 835 MHz에서 phantom 모델을 제작하여 SAR 값을 측정하였다. 그 결과, 전자파 흡수체 부착에 의한 SAR 값은 약 18 % 감소하였고, 안테나의 정재파비 및 패턴은 기존의 것과 거의 일치하였으며, 이득은 약 0.3 dB 감소하였다. 그러나 휴대폰의 수신감도는 전반적으로 약 1 dB 향상되었다.

• Biomaterials and Biomechanics in Bioengineering
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• 제1권2호
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• pp.73-79
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• 2014

Covalent attachment of 1, 4-dimethylnaphthalene (DMN) based endoperoxide forming subunits to a polyvinyl butyral (PVB) backbone has been achieved. The functionalized polymer materials prepared and characterized here can serve as biocompatible carrier systems for studying cellular uptake, intermediate storage and delayed release of singlet oxygen, which opens up new doors for optimizing a variety of medical applications of photogenerated DMN-endoperoxides such as antiviral, antibacterial, antiplasmodial and antitumor activity.

• BMB Reports
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• 제31권6호
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• pp.525-535
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• 1998

A critical step in the faithful translation of genetic information is specific tRNA recognition by aminoacyl-tRNA synthetases. These enzymes catalyze the covalent attachment of particular amino acids to the terminal adenosine of cognate tRNA substrates. In general, there is one synthetase for each of the twenty amino acids and each enzyme must discriminate against all of the cellular tRNAs that are specific for the nineteen noncognate amino acids. Primary sequence information combined with structural data have resulted in the division of the twenty synthetases into two classes. In recent years, several high-resolution co-crystal structures along with biochemical data have led to an increased understanding of tRNA recognition by synthetases of both classes. The anticodon sequence and the amino acid acceptor stem are the most common locations for critical recognition elements. This review will focus on acceptor stem discrimination by class II synthetases. In particular, the results of in vitro aminoacylation assays and site-directed and atomic group mutagenesis studies will be discussed. These studies have revealed that even subtle atomic determinants can provide signals for specific tRNA aminoacylation.