• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.183-191
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• 2008

Volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. And VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Benzene is the most widely used prototypical VOC and the toxic mechanisms of them are still unclear. The multi-step process of toxic mechanism can be more fully understood by characterizing gene expression changes induced in cells by toxicants. In this study, DNA microarray was used to monitor the expression levels of genes in HepG2 cells and HL-60 cells exposed to the benzene on IC20 and IC50 dose respectively. In the clustering analysis of gene expression profiles, although clusters of HepG2 and HL-60 cells by benzene were divided differently, expression pattern of many genes observed similarly. We identified 916 up-regulated genes and 1,144 down-regulated genes in HepG2 cells and also 1,002 up-regulated genes and 919 down-regulated genes in HL-60 cells. The gene ontology analysis on genes expressed by benzene in HepG2 and HL-60 cells, respectively, was performed. Thus, we found some principal pathways, such as, focal adhesion, gap junction and signaling pathway in HepG2 cells and toll-like receptor signaling pathway, MAPK signaling pathway, p53 signaling pathway and neuroactive ligand-receptor interaction in HL-60 cells. And we also found 16 up-regulated and 14 down-regulated commonly expressed total 30 genes that belong in the same biological process like inflammatory response, cell cycle arrest, cell migration, transmission of nerve impulse and cell motility in two cell lines. In conclusion, we suggest that this study is meaningful because these genes regarded as strong potential biomarkers of benzene independent of cell type.

• Journal of Periodontal and Implant Science
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• 제41권1호
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• pp.30-43
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• 2011

Purpose: Under different culture conditions, periodontal ligament (PDL) stem cells are capable of differentiating into cementoblast-like cells, adipocytes, and collagen-forming cells. Several previous studies reported that because of the stem cells in the PDL, the PDL have a regenerative capacity which, when appropriately triggered, participates in restoring connective tissues and mineralized tissues. Therefore, this study analyzed the genes involved in mineralization during differentiation of human PDL (hPDL) cells, and searched for candidate genes possibly associated with the mineralization of hPDL cells. Methods: To analyze the gene expression pattern of hPDL cells during differentiation, the hPDL cells were cultured in two conditions, with or without osteogenic cocktails (${\beta}$-glycerophosphate, ascorbic acid and dexamethasone), and a DNA microarray analysis of the cells cultured on days 7 and 14 was performed. Reverse transcription-polymerase chain reaction was performed to validate the DNA microarray data. Results: The up-regulated genes on day 7 by hPDL cells cultured in osteogenic medium were thought to be associated with calcium/iron/metal ion binding or homeostasis (PDE1A, HFE and PCDH9) and cell viability (PCDH9), and the down-regulated genes were thought to be associated with proliferation (PHGDH and PSAT1). Also, the up-regulated genes on day 14 by hPDL cells cultured in osteogenic medium were thought to be associated with apoptosis, angiogenesis (ANGPTL4 and FOXO1A), and adipogenesis (ANGPTL4 and SEC14L2), and the down-regulated genes were thought to be associated with cell migration (SLC16A4). Conclusions: This study suggests that when appropriately triggered, the stem cells in the hPDL differentiate into osteoblasts/cementoblasts, and the genes related to calcium binding (PDE1A and PCDH9), which were strongly expressed at the stage of matrix maturation, may be associated with differentiation of the hPDL cells into osteoblasts/cementoblasts.

• 한국정보처리학회논문지
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• 제7권9호
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• pp.2857-2866
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• 2000

소프트웨어 개발 기술이 발전함에 따라 객체지향 CASE(Computer Aided Software Engineering)도구의 중요성이 점차 커지고 있다. 본 논문에서는 객체지향 CASE 도구인 OODesigner[15, 16]를 세가지 플랫폼에서 개발한 공정을 기술하고, 구현된 도구들의 설계 및 구현 결과 유사성을 기술하며, CASE 도구 개발을 위한 설계 및 구현 관점의 일반적인 구조를 제시한다. OODesigner는 초기에 OMT(Object Modeling Technique)를 지원하기 위한 목적으로 1994년부터 개발되기 시작하였으며, 1997년에 Unix 버전이 완성된 이후 UML(Unified Modeling Language)을 지원하는 Java 버전과 Windows 버전의 개발이 이루어졌다. CASE 도구 개발은 Model-View-Controller(MVC)패러다임을 적용하는 전형적인 예라고 볼 수 있으며 구현 결과 MVC 관점에서 세가지 버전들의 공통된 설계 패턴들을 얻을 수 있었다, 이러한 설계의 유사성들은 해당되는 설계 표기법을 지원하는 다양한 CASE 도구의 개발을 사용될 수 있다.

• 방사성폐기물학회지
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• 제18권2호
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• pp.119-131
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• 2020

국내 중·저준위 방사성폐기물 처분시설로 고려되고 있는 표층처분시설의 불포화대에서 핵종 이동을 야기하는 지하수 유동을 평가하기 위하여 유한요소법 기반의 COMSOL Multiphysics을 이용한 수치모델을 개발하였다. 그리고, 처분장 가장자리를 대상으로 처분고, 뒤채움재, 처분덮개로 구성되는 표층처분시설과 그 아래에 위치한 불포화대를 포함한 수직 2차원의 모델 영역을 구성하여, 시나리오 별 모델링을 수행하였다. 지속적 강수 유입 조건과 간헐적 강수 유입 조건 비교에서 포화도의 파동 현상을 제외하고는 뚜렷한 차이점을 보이지 않는 것으로 판단되었다. 불포화대의 공극률이나 잔류함수비와 같은 입력 자료는 전반적으로 불포화대 지하수 유동에 큰 영향도가 없는 것으로 판단되었다. 하지만, 불포화대의 수리전도도는 지하수 유동에 큰 영향을 미치는 것으로 판단되었다. 즉, 처분고로의 지하수 유입 속도를 판단하기 위해서는 불포화대의 수리전도도 특성이 신중하게 고려되어야 할 것으로 판단되었다.

• Journal of Information Processing Systems
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• 제3권2호
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• pp.43-53
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• 2007

The use of agent paradigm in today's applications is hampered by the security concerns of agents and hosts alike. The agents require the presence of a secure and trusted execution environment; while hosts aim at preventing the execution of potentially malicious code. In general, hosts support the migration of agents through the provision of an agent server and managing the activities of arriving agents on the host. Numerous studies have been conducted to address the security concerns present in the mobile agent paradigm with a strong focus on the theoretical aspect of the problem. Various proposals in Intrusion Detection Systems aim at securing hosts in traditional client-server execution environments. The use of such proposals to address the security of agent hosts is not desirable since migrating agents typically execute on hosts as a separate thread of the agent server process. Agent servers are open to the execution of virtually any migrating agent; thus the intent or tasks of such agents cannot be known a priori. It is also conceivable that migrating agents may wish to hide their intentions from agent servers. In light of these observations, this work attempts to bridge the gap from theory to practice by analyzing the security mechanisms available in Aglet. We lay the foundation for implementation of application specific protocols dotted with access control, secured communication and ability to detect tampering of agent data. As agents exists in a distributed environment, our proposal also introduces a novel security framework to address the security concerns of hosts through collaboration and pattern matching even in the presence of differing views of the system. The introduced framework has been implemented on the Aglet platform and evaluated in terms of accuracy, false positive, and false negative rates along with its performance strain on the system.

• 한국인구학
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• 제18권2호
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• pp.98-114
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• 1995

이 연구는 급격한 변동을 겪어 온 한국사회에서 도시화가 어떻게 이루어지고 있고 도시인구의 분포의 측면에서 불평등이 어떻게 이루어져 있는지를 살펴보고 있다. 이 연구결과 1966-70년 사이에 급격히 이루어진 도시화의 성격이 부각되었고, 또 도농간의 성장속도의 차이도 아주 높았음이 드러났다. 무엇보다도 서울의 수위도시성이 명백히 드러났다. 하지만 서울의 수위도시성은 1970년이래 서서히 감소되기 시작했고, 불평등지수인 지니계수를 통해 검증한 결과 1970년에 비해 1990년의 도시인구분포의 불평등성은 완화된 것으로 보이나, 여전히 큰 불평등이 존재하고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9211-9216
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• 2014

CXCR7 is involved in tumor development and metastasis in multiple malignancies. However, the function and molecular mechanisms of action of CXCR7 in human cervical cancer are still unclear. In the present study a loss of-function approach was used to observe the effects of recombinant CXCR7 specific small interfering RNA pBSilence1.1 plasmids on biological behavior including proliferative activity and invasive potential, as indicated by MTT assays with the cervical cancer SiHa cell line in vitro. Reverse transcription polymerase chain reaction and Western blotting revealed that CXCR7 was downregulated in transfected compared with control cells, associated with inhibited cell growth, invasiveness and migration. The expression of CXCR7 and CXCL12 was also determined immunohistochemically in 152 paraffin-embedded, cervical squamous cell carcinoma (CSCC) and cervical intraepithelial neoplasia (CIN), or normal cervical epithelial to assess clinico-pathological pattern and CXCR7 status with respect to cell differentiation and lymph node metastasis in Uighur patients with CSCC. CXCR7 and CXCL12 expression was higher in cervical cancer than CIN and normal cervical mucosa, especially in those with higher stage and lymph node metastasis. CXCL12 appeared to be positively regulated by CXCR7 at the post-transcriptional level in CSCC. We propose that aberrant expression of CXCR7 plays a role in carcinogenesis, differentiation and metastasis of CSCC, implying its use as a potential target for clinical biomarkers in differentiation and lymph node metastasis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권3호
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• pp.205-211
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• 2001

Cleft palate is one of the most serious congenital anomalies in human that causes a sucking problem in newborn babies and morphologic deformity that usually leads to death in newborn mouse offspring due to an insufficient ability to suck milk. Therefore cleft palate had been researched with epidemiologic and molecular methods, and many etiologic factors were examined closely. Among of the research methods, biologic molecule researches have been more important method for cleft palate formation study. The $TGF-{\beta}$ had an important role in the cell migration, epithelial-mesenchymal transdifferentiation, extracellular matrix synthesis and deposition. But there was a little research which was study about correlation cleft palate induced by beta-aminonitroproprionitrile(BAPN) with $TGF-{\beta}$ expression. A purpose of this presented study was examed how $TGF-{\beta}$ expression in cleft palate mice. At gestation days 13, BAPN-monofumarate salts($(C_3H_6N_2)_2$ ${\cdot}$ $C_4H_4O_4$, Sigma Co.) was single oral administered to 4 pregnant rats according to 1g/kg body weight. And pregnant rats were sacrificed on day 20 post coitus(p.c.), The $TGF-{\beta}$ expression patterns of cleft formed fetus mice was followed that; 1.Osteoblast, mesenchymal cell and epithelial cell of cleft mice were low expression compare to control mice. 2.There was no $TGF-{\beta}$ difference expression pattern of osteocyte of cleft mice compare to control mice. 3. In western blot analysis, thickness of band of $TGF-{\beta}$ in cleft mice was thin and dilute compare to control mice.

• 구강회복응용과학지
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• 제27권4호
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• pp.423-436
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• 2011

교합성 외상은 과도하거나 비정상적인 교합력으로 인한 치아의 주위에 발생하는 병적 변화를 말한다. 교합성 외상과 치주질환과의 관계에 대한 다양한 논쟁이 있었지만 위험요소임은 확실하기 때문에 교합조정을 하는 것이 치주치료의 결과를 개선시킬 수 있다. 정상적인 치주조직을 가진사람이라도 저작양태와 교합양상 및 전치피개의 양상에 따라 교합외상이 발생할 가능성이 있다. 치주질환으로 인해 이차적인 교합외상이 있으면 다양한 문제점을 유발할 가능성이 있는데 특히 구치가 상실되면 교합의 안정을 위협받게 된다. 상실된 구치를 수복하지 않아도 된다는 개념부터 반드시 회복시켜야 한다는 극단적인 주장이 있지만 양쪽의 주장 모두 교합의 안정성을 최우선의 목표로 한다는 점에서는 일치한다. 또한 구치가 상실되면 대합치의 변위나 정출 뿐 아니라 전치의 변위까지도 유발할 수 있기 때문에 교합성 외상을 제거하고 교합의 안정성을 확보하기 위한 치료가 필수적이다.

• 한국패류학회지
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• 제7권1호
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• pp.76-86
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• 1991

A scanning electron microscopic stuey on the glochidial encystment study on the golchidal encystment and excystment of Anodonta fukudai on Acheilognathus yamatsutae, a common natural hostfish, was conducted. The glochidium easily attached to the unscaled surfaces of the host fish such as the fins, lips, and the wall of the buccal cavity. For this study, the fins infected with the glochidia wer mainly observed in a series. The process of encystment was slowly progressed, for 21-25 hours for the early cyst and for 2-4 days for the thick walled cyst. The process of excystmint was visually detected on the 12th day since the attachmint was occurred. The first visible sign was a little tear of the cyst wall covering the hinge and marginal zones of the juvenile clam and once the little sign was appeared the progress of emerging and dettachmint of the juvenile clam from the host was finished relatively in short time. During the process of the encystmint, the cells participationg in covering the attached glochidirm were seened mainly supplied by migration from the surroundings. the shapes of the cells migrating and covering the glochidium were considerably changed and the surface structures of the cells lost their normal pattern of the surface ridges. The unstable forms of the cells were observed almost all throughout the period of the glochidial attachment. No cells of the host epithelium, which were still attached to the juvenile clam energing from the cyst, were observed. The most juvenile clams escaped from the cysts were a little bigger than the glochidia and they were still possessed of the golchidial hooks even though much degenerated. The first growth line was appeared on the shell valves of the juvenild clam when observed right after dettachment.