• 한국인터넷방송통신학회논문지
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• 제18권5호
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• pp.251-257
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• 2018

경쟁업체 $F_A$가 k개 점포로 시장을 독점하고 있는 상황에서, 동종업계의 신규 업체 $F_B$가 경쟁업체보다 고객을 보다 많이 확보하여 경쟁우위를 가질 수 있는 k 점포를 신규로 개설하고자 한다. 이 경우 어느 위치에 점포를 개설해야 하는가가 문제로 대두된다. 이 문제에 대해 Serra와 Revelle의 PREMAL은 k-Median과 LP+BB를 사용한 MAXCAP 정수계획법으로 $F_B$의 점포 위치 k개를 결정한 다음 $F_B$의 점포 위치가 보다 많은 고객을 확보하는 위치로 변경하는 방법을 제안하였다. 본 논문에서는 정수계획법 도움 없이 단지 MS-Excel을 활용하여 최 외곽 노드들을 제외하고, $F_A$ 점포 위치 u에 대해 ${\upsilon}{\not\in}N_G(u)$들을 대상으로 $F_B$의 점포 위치를 결정하는 비근방 탐색법을 제안하였다. 실험 결과 제안된 알고리즘은 정수계획법에 비해 쉽고 빠르게 해를 구할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6211-6216
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• 2012

Objective: To investigate the effects of gambogic acid (GA) on the growth of human malignant glioma cells. Methods: U251MG and U87MG human glioma cell lines were treated with GA and growth and proliferation were investigated by MTT and colony formation assays. Cell apoptosis was analyzed by annexin V FITC/PI flow cytometry, mitochondrial membrane potential assays and DAPI nuclear staining. Monodansylcadaverine (MDC) staining and GFP-LC3 localisation were used to detect autophagy. Western blotting was used to investigate the molecular changes that occurred in the course of GA treatment. Results: GA treatment significantly suppressed cell proliferation and colony formation, induced apoptosis in U251 and U87MG glioblastoma cells in a time- and dose-dependent manner. GA treatment also lead to the accumulation of monodansylcadaverine (MDC) in autophagic vacuoles, upregulated expressions of Atg5, Beclin 1 and LC3-II, and the increase of punctate fluorescent signals in glioblastoma cells pre-transfected with GFP-tagged LC3 plasmid. After the combination treatment of autophagy inhitors and GA, GA mediated growth inhibition and apoptotic cell death was further potentiated. Conclusion: Our results suggested that autophagic responses play roles as a self-protective mechanism in GA-treated glioblastoma cells, and autophagy inhibition could be a novel adjunctive strategy for enhancing chemotherapeutic effect of GA as an anti-malignant glioma agent.

• BMB Reports
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• 제36권3호
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• pp.275-281
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• 2003

An E1B-defective adenovirus, named r2/Ad carrying the neo expression cassette, was constructed by homologous recombination. The construction, selection (using neomycin as a selective marker), and propagation of the recombinant virus was performed in human embryonic kidney 293 cells (HEK 293). An in vitro study demonstrated that this recombinant virus has the ability to replicate in and lyse some p53-deficient human tumor cells such as human glioma tumor cells (U251) and human bladder cells (EJ), but not in some cells with functional p53, such as human adenocarcinoma cells (A549) and human fibroblast cells (MRC-5). Also, based on the cytopathic effect (CPE), it was demonstrated, under identical conditions, that the U251 cells were more sensitive to r2/Ad replication than the EJ cells. In this paper, we report that r2/Ad could be very useful in studying the in vitro selective replication of E1B-defective adenovirus and has great potential in cancer gene therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10181-10185
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• 2015

Background: MicroRNAs, small noncoding RNA molecules, can regulate mammalian cell growth, apoptosis and differentiation by controlling the expression of target genes. The aim of this study was to investigate the function of miR-323-5p in the glioma cell line, U251. Materials and Methods: After over-expression of miR-323-5p using miR-323-5p mimics, cell growth, apoptosis and migration were tested by MTT, flow cytometry and cell wound healing assay, respectively. We also assessed the influence of miR-323-5p on the mRNA expression of IGF-1R by quantitative real-time reverse transcriptase PCR (qRT-PCR), and on the protein levels by Western blot analysi. In addition, dual-luciferase reporter assays were performed to determine the target site of miR-323-5p to IGF-1R 3'UTR. Results: Our findings showed that over-expression of miR-323-5p could promote apoptosis of U251 and inhibit the proliferation and migration of the glioma cells. Conclusions: This study demonstrated that increased expression of miR-323-5p might be related to glioma progression, which indicates a potential role of miR-323-5p for clinical therapy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.251-251
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• 2009

The generation of energy and the cooling of system using thermoelectric semiconductor material have been in spotlight. Thermoelectric effect increases with the decrease of the thermal conductivity. In the thermoelectric devices, thermal conductivity is related to phonon scattering. Therefore, few studies have been conducted in the thermoelectric materials dispersed nano oxide particle for increasing the phonon scattering. However, core-shell structure which nano particle disperses in solvents and then which thermoelectric materials coated on the nano oxide particles has not been reported. In this study, we selected commercial nano powder such as $Al_2O_3$. This nano particle was about 20nm and was crushed aggregate by mechanical treatment. We have developed the effect of the dispersant and the solvent. The properties of particles were evaluated by SEM, TEM, particle size analysis, and BET. Dispersion and dispersion stability were evaluated by electronic microscope and turbidity.

• 대한화학회지
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• 제56권2호
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• pp.251-256
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• 2012

A novel series of benzothiazole derivatives were synthesized and assayed in vivo to investigate their hypoglycemic activity by streptozotocin-induced diebetic model in rat. These derivatives showed considerable biological efficacy when compared to glibenclamide, a potent and well known antidiabetic agent as a reference drug. All the compounds were effective, amongst them 3d showed more prominent activity at 100 mg/kg p.o. The experimental results are statistically significant at p<0.01 and p<0.05 level.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 춘계학술발표논문집
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• pp.251-253
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• 2008

RFID 태그에 통신 기능이 부가되고 점차 주위 환경을 감지하는 센싱 기능이 부가되면, 능동적으로 정보를 처리하는 지능형 초소형 스마트 센서 네트워크로 발전되어 현재의 고정된 개체 인식 코드 획득 수준에서 다기능 태그에 의한 상황인지 처리 수준으로 진화하여, 개체간 통신 기능을 갖춘 지능형 USN으로 발전할 것으로 전망 된다. ZigBee는 기기간 센서 네트워크를 구성, 단순 제어와 관리를 수행할 수 있는 WPAN의 최적의 기술로 평가 받고 있으며 저 전력, 저가 등의 장점 등으로 시장 성장성이 높은 기술이다. 유/무선 인프라를 확보하고 있는 우리는 ZigBee를 기존, 또는 현재 구축중인 유무선 네트워크와 연결해 다양한 유비쿼터스 서비스를 개발할 수 있는 최적의 테스트베드 환경을 갖추고 있으므로 u-Health의 기반에 꼭 필요한 기술이다.

• Journal of Korean Neurosurgical Society
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• 제29권4호
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• pp.471-476
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• 2000

Objective : p16/INK4a, a kind of tumor suppressor genes, encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. This prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumor suppressor protein(pRb), thus preventing exit from the G1 phase. According to previous reports, over 50% of glioma tissue and 80% of glioma cell lines have been demonstrated inactivation of p16/INK4a gene. The purpose of this study was to determine whether recombinant adenovirus-p16 virus is a suitable candidate for gene replacement therapy in cases of glioma. Methods : Three human glioma cell lines(U251MG, U87MG and U373MG) that express mutant p16 protein were used. Replication-deficient adenovirus was utilized as an expression vector to transfer exogenous p16 cDNA into the cells ; control cells were infected with the Ad-${\beta}$-gal expressing ${\beta}$-galactosidase. To monitor gene transfer and the expression of exogenous genes, we used Western Blotting analysis. Flow cytometry studies of cellular DNA content were performed to determine the cell cycle phenotype of the glioma cells before and after treatment. Results : We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16 induced growth suppression in vitro. Flow cytometric study revealed that Ad-CMV-p16 infected U87MG cells were arrested during the G0-G1 phase of the cell cycle. Expression of p16 transferred by Ad-CMV-p16 in glioma cells was highly efficient and maintained for more than seven days. Conclusions : Our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

• 한국독어학회지:독어학
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• 제5집
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• pp.223-251
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• 2002

Modalpartikeln, die auch $Abt\"{o}nungspartikeln,\;W\"{u}rzw\"{o}rter,\;F\"{a}rbew\"{o}rter$ usw. genannt werden, galten eine Zeitlang als $\"{U}berfl\"{u}ssiges$. Aber mit der 'kommunikativ­pragrnatischen Wende' hat die Partikelforschung einen enormen Aufschwung genommen. Auch im Femdsprachenunterricht waren Partikeln als etwas Unwichtiges oder in anderen Worten etwas schwer zu Behandelndes geblieben und wurden deshalb zur Seite geschoben. Mit Hilfe der Aufschwung der Partikelforschung in Deutschland untersuchte ich koreanische $\"{U}bersetzungsm\"{o}glichkeiten$ von Modalparikeln. Ich $\"{u}bernahm$ Diewaldische Methode. Sie $schl\"{a}gt$ ein Beschreibungsschema vor: Modalpartikeln haben verweisende und $verkn\"{u}fende$ Funktion. Sie weisen $n\"{a}hmlich$ auf den pragmatischen $Pr\"{a}text\;zur\"{u}ck$ und bringen ihn in relevanter Situation mit der Modalpartikel enthaltenden $\"{A}u{\ss}erung$ in Beziehung. Da braucht man also drei Ebenen: pragmatischer $Pr\"{a}text$, relevante Situation und partikelhaltige $Au{\ss}erung$. Die Schwierigkeit der $\"{U}bersetzungsm\"{o}glichkeiten$ von Modalkartikeln besteht darin, jeweiligen $Pr\"{a}text$ und jeweilige relevante Situation wiederherzustellen und auszudrticken. In diesem Aufsatz geht es nur um 'doch'. 'doch' ist eine der $h\"{a}ufigsten$ Modalpartikeln und tritt in vielen verschidenen Satzarten. 'doch' tritt in Aussage-, Imperativ-, Ausrufe­und Wunschsatzen auf. $Au{\ss}erdem$ tritt 'doch' in $Erg\"{a}nzungsfragen$ und Entscheidungsfragen mit Intonation auf und ist aber nur bei 'echten' Fragen ausgeschlossen. Aus der diachronischen Bedeutungsentwicklung und dem Bedeutungsvergleich zu ihren Homonymen stellten sich die semantischen Merkmale von 'doch' als $Adversativit\"{a}t\;und\;Konzessivit\"{a}t$. Aber diese semantischen Komponenten werden bei dem Modalpartikel $abgeschw\"{a}cht$ und pragmatische Faktoren werden in verschiedenen $Verwendungsm\"{o}glichkeiten$ verstarkt. Unter $Ber\"{u}cksichtigung\;jeweiligen\;Pr\"{a}textes$ und relevanter Situation schlug ich koreanische $\"{U}bersetzungsm\"{o}glichkeiten$ von 'doch' je nach der Satzart und nach der $Verwendungsm\"{o}glichkeit$ vor.

• Journal of Korean Neurosurgical Society
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• 제63권6호
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• pp.698-706
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• 2020

Objective : To study the physiochemical characteristics of podophyllotoxin (PPT) conjugated stearic acid grafted chitosan oligosaccharide micelle (PPT-CSO-SA), and evaluate the ability of the potential antineoplastic effects against glioma cells. Methods : PPT-CSO-SA was prepared by a dialysis method. The quality of PPT-CSO-SA including micellar size, zeta potential, drug encapsulation efficiency and drug release profiles was evaluated. Glioma cells were cultured and treated with PPT and PPT-CSO-SA. The ability of glioma cells to uptake PPT-CSO-SA was observed. The proliferation of glioma cells was determined by 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The apoptosis and morphology of U251 cells were observed by 4',6-Diamidino-2-phenylindole dihydrochloride (DAPI) dye staining. Cell cycle analysis was performed by flow cytometry. The migration ability of U251 cells was determined by wound healing test. Results : PPT-CSO-SA had nano-level particle size and sustained release property. The encapsulation efficiency of drug reached a high level. The cellular uptake percentage of PPT in glioma cells was lower than that of PPT-CSO-SA (p<0.05). The inhibitory effect of PPT-CSO-SA on glioma cells proliferation was significantly stronger than that of PPT (p<0.05). The morphologic change of apoptosis cell such as shrinkage, karyorrhexis and karyopyknosis were observed. The percentage of U251 cells in G2/M phase increased significantly in the PPT-CSO-SA group compared with PPT group (p<0.05). Compared with the PPT group, the cell migration ability of the PPT-CSO-SA group was significantly inhibited after 12 and 24 hours (p<0.05). Conclusion : PPT-CSO-SA can effectively enhance the glioma cellular uptake of drugs, inhibit glioma cells proliferation and migration, induce G2/M phase arrest of them, and promote their apoptosis. It may be a promising anti-glioma nano-drug.