검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 128

        41.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Resistance to the induction of apoptosis is a possible me- chanism by which tumor cells can survive anti-neoplastic treatments. Melanoma is notoriously resistant to anti-neop- lastic therapy. Previous studies have demonstrated focal adhesion kinase (FAK) overexpression in melanoma cell lines. Given its probable role in mediating resistance to apo- ptosis, many researchers have sought to determine whether the downregulation of FAK in melanoma cells would confer a greater sensitivity to anti-neoplastic agents. Genistein is a known inhibitor of protein-tyrosine kinase (PTK), which may attenuate the growth of cancer cells by inhibiting the PTK- mediated signaling pathway. This present study was under- taken to investigate the effect of genistein on the expression of FAK and cell cycle related proteins in the G361 me- lanoma cell line. Genistein was found to have a preferential cyto- toxic effect on G361 melanoma cells over HaCaT normal ke- ratinocytes. Genistein decreased the expression of 125 kDa phosphotyrosine kinase and the FAK protein in particular. Genistein treatment did not affect the expression of p53 in G361 cells in which p21 is upregulated. The expression of cy- clin B and cdc2 was downregulated by genistein treatment. Taken together, our data indicate that genistein induces the decreased proliferation of G361 melanoma cells via the in-hibition of FAK expression and regulation of cell cycle genes. This suggests that the use of genistein may be a via- ble approach to future melanoma treatments.
        4,000원
        43.
        2012.09 구독 인증기관 무료, 개인회원 유료
        Expression of epithelial cell adhesion molecule (EpCAM) in the early phase of hepatocarcinogenesis induced by diethylnitrosamine (DEN) was investigated. At 14 days of age, 60 ICR mice were divided into two groups and treated with saline (group 1) or DEN (group 2, 10 mg/kg of body weight, i.p. injection), and were sacrificed at 6 h and 1, 2, 3, 7, and 28 days after treatment with saline or DEN. During necropsy, half of the liver from saline- or DEN-treated mice was processed for histopathological examination and immunohistochemical staining of EpCAM and apoptosis. The remaining liver tissue was snap-frozen in liquid nitrogen for RNA extraction and analysis of EpCAM mRNA expression. Immunohistochemical examination showed that EpCAM expression was detected only in a small number of hepatocytes from saline-treated mice and its expression was detected in bile duct cells and round cells around portal areas, as well as hepatocytes in the livers of DEN-treated mice. In addition, multiple apoptotic cells were found in the livers of mice treated with DEN. EpCAM mRNA expression was significantly higher in DEN-treated mice at 1, 7, and 28 days compared to saline-treated mice at 6 h (P<0.01). Taken together, EpCAM expression and apoptosis were increased in liver by DEN treatment.
        4,000원
        44.
        2012.09 구독 인증기관 무료, 개인회원 유료
        The shortage of human organs for transplantation has induced the research on the possibility of using animal as porcine. However, pig to human transplantation as known as xeno-transplantation has major problem as immunorejection. Recently, the solutions of pig to human xenotransplantation are commonly mentioned as having a genetically modification which include alpha 1, 3 galatosyl transferase knockout (GTKO) and immune-suppressing gene transgenic model. Unfortunately, the expression level of transgenic gene is very low activity. Therefore, development of gene overexpression system is the most urgent issue. Also, the tissue specific overexpression system is very important. Because most blood vessels are endothelial cells, establishment of the endothelial-specific promoter is attractive candidates for the introduction of suppressing immunorejection. In this study, we focus the ICAM2 promoter which has endothelial-specific regulatory region. To detect the regulatory region of ICAM2 promoter, we cloned 3.7 kb size mini-pig ICAM2 promoter. We conduct serial deletion of 5' flanking region of mini-pig ICAM2 promoter then selected promoter size as 1 kb, 1.5 kb, 2 kb, 2.5 kb, and 3 kb. To analyze promoter activity, luciferase assay system was conducted among these vectors and compare endothelial activity with epithelial cells. The reporter gene assay revealed that ICAM2 promoter has critical activity in endothelial cells (CPAE) and 1 kb size of ICAM2 promoter activity was significantly increased. Taken together, our studies suggest that mini-pig ICMA2 promoter is endothelial cell specific overexpression promoter and among above all size of promoters, 1 kb size promoter is optimal candidate to overcome the vascular immunorejection in pig to human xenotransplantation.
        4,000원
        45.
        2012.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Ti-Ni alloys are widely used in numerous biomedical applications (e.g., orthodontics, cardiovascular science, orthopaedics) due to their distinctive thermomechanical and mechanical properties, such as the shape memory effect, superelasticity and low elastic modulus. In order to increase the biocompatibility of Ti-Ni alloys, many surface modification techniques, such as the sol-gel technique, plasma immersion ion implantation (PIII), laser surface melting, plasma spraying, and chemical vapor deposition, have been employed. In this study, a Ti-49.5Ni (at%) alloy was electrochemically etched in 1M H2SO4+ X (1.5, 2.0, 2.5) wt% HF electrolytes to modify the surface morphology. The morphology, element distribution, crystal structure, roughness and energy of the surface were investigated by scanning electron microscopy (SEM), energy-dispersive Xray spectrometry (EDS), X-ray diffractometry (XRD), atomic force microscopy (AFM) and contact angle analysis. Micro-sized pores were formed on the Ti-49.5Ni (at%) alloy surface by electrochemical etching with 1M H2SO4+ X (1.5, 2.0, 2.5) wt% HF. The volume fractions of the pores were increased by increasing the concentration of the HF electrolytes. Depending on the HF concentration, different pore sizes, heights, surface roughness levels, and surface energy levels were obtained. To investigate the osteoblast adhesion of the electrochemically etched Ti-49.5Ni (at%) alloy, a MTT test was performed. The degree of osteoblast adhesion was increased at a high concentration of HF-treated surface structures.
        4,000원
        46.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recurrence-metastasis status of squamous cell carcinoma of tongue is a challenging oncologic problem. This study examined the expression of E-cadherin/β-catenin cell adhesion complex in squamous cell carcinoma of the tongue through an immunohistochemical study. Twenty samples from 15 patients with squamous cell carcinoma of the tongue, who were treated at the Department of Oral and Maxillofacial Surgery, consisted of primary or recurrent tumors along with matched metastatic lymph nodes were retrieved for immunohistochemical staining and grouped based on recurrence-metastasis status.Differences in stain localization were noted in E-cadherin, β–catenin and phospho β–catenin staining between different tumor groups based on the recurrence-metastasis status. The number of phospho β-catenin stain positive cells was found to have a significant role in survival. E-cadherin confirms its role as a powerful individual differentiation indicator and the role of β-catenin specially the phospho type elicts interest
        4,600원
        47.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        EGCG has inhibitory effect on a variety of cancers by inducing apoptosis and cell cycle arrest or inhibiting angiogenesis and metastasis. EGCG has been found to induce apoptosis in salivary gland carcinoma cells. But the potential anti-invasive effect of EGCG in salivary gland cancer has not been studied yet. The aim of this study is to evaluate the effect of EGCG on salivary gland adenocarcinoma SGT cell adhesion and migration to Type I collagen treatment. Western blot, adhesion and migration assay were performed to evaluate the impacts of EGCG on the expression of MMP-2/-9 and its upstream signaling molecules after treatment of type I collagen. SGT cell adhesion to type I collagen is significantly suppressed by EGCG. EGCG decreased expression of β1 integrin, phosphorylation of FAK, MMP-2/-9 compared with type I collagen treatment. In addition, EGCG inhibited the migration of SGT cells treated with type I collagen. These results suggest that EGCG could effectively inhibit the invasion and migration of human SGT cells by downregulating the expression of β1 integrin and MMP-2/-9 and phosphorylation of FAK, Akt, and Erk. Adhesion and migration to type I collagen of SGT cells can be influenced through EGCG.
        4,000원
        49.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A method of functionalization of multi-walled carbon nanotube (MWNT) at room temperature using dry ozone gas is described. The resulting MWNT were characterized by Fourier transform infrared, x-ray photoelectron spectroscopy, and scanning electron microscopy. Combined to these analyses and solubility in liquids, it could be concluded that the dry ozone gas exposure introduces polar functional groups such as carboxylic groups to MWNT similar to acidic modification of MWNT. Particularly, the stable dispersion of MWNT in water after ozone treatment above a critical level could be obtained, implying potential bio-application. The hydrophilic functional groups on the MWNT introduced by ozone oxidation were helpful in improving the interaction with functional groups in PA6 such as -NH2 and -CONH- resulting in improved mechanical properties.
        4,000원
        50.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyurethane adhesive is used in various fields as flexible packaging materials including a food packaging field. Therefore, the purpose of this study is synthesis of polyurethane adhesive which uses aliphatic isocyanate, and compares with aromatic isocyanate. The isocyanates for this test are toluene-2,4-diisocyanate(TDI), hexamethylene diisocyanate(HDI), 4,4-dicyclohexyl ethane diisocyanate(H12MDI), and isophorone diisocyanate(IPDI). And, the effect of any other diisocyanate are evaluated by several methods as for curing rate test, accelerate weathering test, and peel strength test. The polyurethane adhesive using curing catalyst and HDI has adhesion strength of about 560 g/15 mm between aluminium foil and nylon, about 1,520 g/15 mm between nylon and CPP. Those parameters are similar to polyurethane adhesive with TDI. Also, in case of curing rate, those are similar to TDI type polyurethane adhesive. Moreover, data of δE as color variation by QUV tester is equal to 4.12, as 48% against those of TDI type.
        4,000원
        52.
        2010.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        3-D IC integration enables the smallest form factor and highest performance due to the shortest and most plentiful interconnects between chips. Direct metal bonding has several advantages over the solder-based bonding, including lower electrical resistivity, better electromigration resistance and more reduced interconnect RC delay, while high process temperature is one of the major bottlenecks of metal direct bonding because it can negatively influence device reliability and manufacturing yield. We performed quantitative analyses of the interfacial properties of Al-Al bonds with varying process parameters, bonding temperature, bonding time, and bonding environment. A 4-point bending method was used to measure the interfacial adhesion energy. The quantitative interfacial adhesion energy measured by a 4-point bending test shows 1.33, 2.25, and 6.44 J/m2 for 400, 450, and 500˚C, respectively, in a N2 atmosphere. Increasing the bonding time from 1 to 4 hrs enhanced the interfacial fracture toughness while the effects of forming gas were negligible, which were correlated to the bonding interface analysis results. XPS depth analysis results on the delaminated interfaces showed that the relative area fraction of aluminum oxide to the pure aluminum phase near the bonding surfaces match well the variations of interfacial adhesion energies with bonding process conditions.
        4,000원
        53.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have previously shown that 5’-nitro-indirubinoxime (5’-NIO) has potent anti-tumor effect in various human cancer cells. But the potential anti-invasive effect of 5’-NIO in salivary gland cancer has not been studied yet. The goal of this study is to evaluate the effect of 5'-NIO on salivary gland adenocarcinoma SGT cell adhesion and migration to Type I collagen treatment. Western blot, adhesion and migration assay were performed to evaluate the impacts of 5’-NIO on the expression of MMP-2/-9 and its upstream signaling molecules after treatment of type І collagen. SGT cell adhesion to type I collagen is significantly suppressed by 5’-NIO. 5’-NIO decreased expression of β1 integrin, phosphorylation of FAK, MMP-2/ -9 compared with type I collagen treatment. In addition, 5’-NIO inhibited the migration of SGT cells treated with type I collagen. These results suggest that 5’-NIO could effectively inhibit the invasion and migration of human SGT cells by downregulating the expression of β1 integrin and MMP-2/-9 and phosphorylation of FAK, Akt, and Erk. Adhesion and migration to type I collagen of SGT cells can be influenced through 5’-NIO..
        4,000원
        55.
        2009.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This paper describes an improved strategy for controlling the adhesion force using both the antiadhesion and adhesion layers for a successful large-area transfer process. An MPTMS (3-mercaptopropyltrimethoxysilane) monolayer as an adhesion layer for Au/Pd thin films was deposited on Si substrates by vapor self assembly monolayer (VSAM) method. Contact angle, surface energy, film thickness, friction force, and roughness were considered for finding the optimized conditions. The sputtered Au/Pd (~17 nm) layer on the PDMS stamp without the anti-adhesion layer showed poor transfer results due to the high adhesion between sputtered Au/Pd and PDMS. In order to reduce the adhesion between Au/Pd and PDMS, an anti-adhesion monolayer was coated on the PDMS stamp using FOTS (perfluorooctyltrichlorosilane) after O2 plasma treatment. The transfer process with the anti-adhesion layer gave good transfer results over a large area (20 mm × 20 mm) without pattern loss or distortion. To investigate the applied pressure effect, the PDMS stamp was sandwiched after 90˚ rotation on the MPTMS-coated patterned Si substrate with 1-μm depth. The sputtered Au/Pd was transferred onto the contact area, making square metal patterns on the top of the patterned Si structures. Applying low pressure helped to remove voids and to make conformal contact; however, high pressure yielded irregular transfer results due to PDMS stamp deformation. One of key parameters to success of this transfer process is the controllability of the adhesion force between the stamp and the target substrate. This technique offers high reliability during the transfer process, which suggests a potential building method for future functional structures.
        4,000원
        57.
        2009.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In the microelectronics packaging industry, the adhesion strength between Cu and polyimide and the thermal stability are very important factors, as they influence the performance and reliability of the device. The three different buffer layers of Cr, 50%Cr-50%Ni, and Ni were adopted in a Cu/buffer layer/polyimide system and compared in terms of their adhesion strength and thermal stability at a temperature of 300˚C for 24hrs. A 90-degree peel test and XPS analysis revealed that both the peel strength and thermal stability decreased in the order of the Cr, 50%Cr-50%Ni and Ni buffer layer. The XPS analysis revealed that Cu can diffuse through the thin Ni buffer layer (200Å), resulting in a decrease in the adhesion strength when the Cu/buffer layer/polyimide multilayer is heat-treated at a temperature of 300˚C for 24hrs. In contrast, Cu did not diffuse through the Cr buffer layer under the same heat-treatment conditions.
        4,000원
        58.
        2009.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        안토시아닌(Anthocyanin)은 플라보노이드계 화합물의 한 부류로 항산화, 항암 및 항궤양, 항당뇨, 중금속해독, 시력보호, 콜레스테를 저하 등의 다양한 생리활성을 가지는 것으로 보고되어 있다. 죽상경화과정은 염증성 사이토카인의 분비 또는 혈관손상으로 인한 백혈구의 부착과 이동을 통해 시작된다. 본 연구는 이러한 죽상경화의 초기과정에서 안토시아닌 혼합물 중 single compound인 delphinidin chloride (DC) 인간혈관 내피세포
        4,000원
        59.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Porphyromonas gingivalis, a major periodontal pathogen, has been implicated in the initiation and progression of periodontal disease. Endothelial dysfunction (Editor note: Aberrant and dysfunction are somewhat redundant. The authors may want to choose one or the other.) contributes to chronic periodontal inflammation. Using cDNA-representational difference analysis, we found that P.gingivalis lipopolysaccharide differentially induces a number of genes in human microvascular endothelial cells. Among these upregulated genes, we focused on intercellular adhesion molecule-1 (VCAM-1), which is crucial for leukocyte recruitment during vascular inflammation. P. gingivalis LPS significantly increased the expression of vascular cell adhesion molecule-1 (VCAM-1) as well as ICAM-1. Promoter assays revealed that the transcription of these cell adhesion molecules was mainly regulated by nuclear factor-xB (NF-xB) in endothelial cells. Furthermore, P. gingivalis LPS significantly increased leukocyte adhesiveness to microvascular endothelial cells and to aortic endothelium. Taken together, our results demonstrate that P. gingivalis LPS activates microvascular endothelial cells through NF-xB-dependent expression of cell adhesion molecules.
        4,000원
        1 2 3 4 5