Internalization and expression of extracellular molecules into cells and tissues is known very important process to biological processes and therapy of various diseases. In this study, we analyzed expression pattern of extracellular molecule after transduction into various human cells. To investigate cellular expression of internalized molecule, we used adenovirus containing green fluorescence protein. After infection of adenovirus into various human cells, the efficiency of intracellular gene expression was assessed with determining GFP expressing cells by fluorescence microscopy or FACS. After one day of adenovirus infection into HepG2 and A549, we observed that GFP expression was low at 10moi but expression levels were increased at 100moi in both cells. But, adenovirus infection into HCT116 showed low expression of GFP at concentrations from 1moi to 100moi. After 2 day infection with adenovirus, GFP expression level at 10moi and 100moi was highly increased in HepG2 and A549 compared with 1 day infection. Especially, GFP expression was significantly increased in HCT116 after 2 days infection. However, GFP expressing SKOV3 cells by adenovirus infection were not found in all the experimental conditions tested. For quantitative analysis of GFP expression of cells by adenovirus infection, we carried out FACS analysis. As a result, GFP was expressed at very low levels at 1moi in all cells used in this experiment. GFP expression slightly increased after increasing moi to 10 in HepG2, HCT116, and A549 cells. By 100moi infection of adenovirus, GFP expression was elevated to 10 fold higher than 10moi in HepG2 and A549 and about 4 fold elevation was observed in HCT116. A549 showed 20 fold higher expression of GFP than SKOV3. We also found that GFP expression by adenovirus infection was the highest in HepG2 cells. Protein expression was enhanced by increasing concentrations or time of adenovirus infection. In these results, GFP expression efficiency of adenoviral gene transduction reveals the highest in HepG2 and lowest in SKOV3 among the cells tested. Taken together, we could confirm that intracellular protein expression efficiency by transduction of extracellular gene was different in various human cells. Our study suggests that the cell types and cellular properties should be carefully examined to enhance expression efficiency of extracelluar molecules in biological research and disease therapy

For investigate intracellular function and role of genes in the biological processes, various gene delivery methods into cell have been developed. Many studies performed to construct optimum conditions of gene delivery into cells and tissues. In this study, we examined efficiency of gene delivery-complexed with cationic lipid vector in human cancer cell lines. GFP plasmids were complexed with cationic lipid and transfected into human cancer cell lines at different concentrations. And then, expression of GFP was analysed with fluorescent microscope and FACS. To determine efficiency of gene delivery, we investigated GFP expression level in various cancer cell lines. GFP expression cells were not shown in hepatocellular carcinoma cell line HepG2 and lung carcimona cell line A549 after 24hr transfection, while, GFP expression cells were observed at 500ng concentration after 48hr transfection. In colorectal carcinoma cell line HCT116, GFP expression cells were observed at 100ng and 500ng concentrations after 24hr transfection and slightly increased at 48hr. After transfection into ovary adenocarcinoma cell line SKOV3, we could found that many cells expressed GFP at 500ng concentration after 24hr and highly elevated GFP expression cells after 48hr. For further evaluate gene expression level, we confirmed GFP expression level by using FACS analysis after 48hr transfection. As a result, HepG2 was expressed GFP in very low level at 10ng, 100ng, and 500ng concentrations. We also identified that GFP was expressed low level at 10ng and 100ng in HCT116 and A549, but highly increased at 500ng concentration to 14.19% and 16.57%, respectively. In case of SKOV3, GFP expression was highly elevated to 13.14% at 100ng and 58.10% at 500ng compared with 10ng transfection. By Comparing efficiency of gene expression among cancer cell lines, GFP expression was similar with cell lines at 10ng transfection, but significantly differed from cell lines at 500ng higher concentration. Additionally, GFP expression level of SKOV3 was showed about 10 fold higher than HepG2, and about 4 fold higher than HCT116 and A549 at 500ng. These results demonstrated that efficiency of gene delivery-complexed with cationic lipid vector was the highest in SKOV3, while HepG2 was showed the lowest efficiency. Taken together, we could determined that efficiency of gene delivery into cells differed from each human cancer cell lines. Our study suggest that cellular properties should be considered in gene delivery-complexed with cationic lipid vector to improve cellular expression efficiency of gene.

The effect of a-sexithiophene(α-6T) layers on the light emitting diode (LED) were studied. The α-6T was used for a buffer layer in electroluminescent (EL) devices. Enhanced carrier (hole) injection and improved emission efficiency were observed. Carrier injection characteristics were investigated as a function of α-6T later thickness. The efficiency of the electroluminescence was proportional to the thickness of α-6T layer. The highest efficiency was observed 600A of α-6T later, which was about 1.5 times higher than that of device without α-6T later. The device with a-6T showed an operation voltage lowered by 2V. The α-6T layer can substitute hole blocking layer, and control charge injection properties.

The N-docosyl N'-methyl viologen-(TCNQ)2, (DMVT) was synthesized. We investigated the π-A isotherm of DMVT to find the optimal deposition condition. Temperature-dependent current-voltage characteristics of the DMVT LB films shows that there is an increase in conductivity at 330K or so. The in-plane electrical conductivity at room temperature is in the range of 10-7~10-6S/cm. From the plot of logarithmic conductivity as a function of reciprocal temperature, two types of activation energies, 0.04eV and 0.73eV, were obtained depending on the temperature range. The Ohmic behaviour was observed below 0.6V and the Schottky effect was confirmed at 2.5~6V, when the I-V characteristics was measured with Al/LB film/Al structure. I-V measurement for Al/LB film/ITO structure showed the asymmetrical I-V relationship, which resulted from the rectification property.

BaTiO3세라믹에서 미세구조를 조절하기 위하여 Ba/Ti비 변화에 따른 소결거동 및 비정상 입자성장에 대하여 연구하였다. 본 연구에서 사용한 BaTiO3분말은 BaCO3와 TiO2를 이용하여 일반적인 고상반응법으로 제조하였다. Ba/Ti비가 감소할수록(과잉 TiO2가 증가할수록)소결 시작온도가 낮아졌으며 치밀화가 증진되었다. 이것은 과잉 TiO2양이 증가할수록 하소된 분말의 크기가 감소되었기 때문으로 판단되며, 공융액상 형성으로 인한 액상소결에 의한 것이 아님을 알 수 있었다. 또한 과잉 TiO2양이 증가할수록 입자성장이 강력하게 억제되었으며, 이는 Ti-rich 이차상이 입자성장을 억제시킴을 의미한다. 따라서 이러한 이차상의 불균일한 분포로 인하여 비정상 입자성장이 일어나는 것으로 판단되었다.

In ubiquitous computing environments, users want to receive the robot services regardless of various physical status or devices such as time, place, various sensors, and high-performance servers. Thus, the ubiquitous service robots have to provide users with automated services according to situational information that they properly recognize. Beyond these problems, robot software has to establish a foundation to support the functions with the network infrastructure that are not able to be solved by a single independent resource. On the basis of a robot middleware that is capable of minimizing dependencies among hierarchy structures, the robot software also has to provide execution environment to control the flow of robot application services. In this paper, we propose a layered architecture to provide users with automated services through ubiquitous robots. The proposed architecture is based on CAWL (Context-Aware Workflow Language) and RSEL (Robot Services Execution Language). CAWL easily represents the flow of robot services from user application service levels, and RSEL is able to support the composition and reusability of robot services through abstraction of robot device services. In our experiments, we applied the proposed architecture to an example of “booth guide robot service.”

A URC, which is a Ubiquitous Robot Companion, provides services to users in ubiquitous computing environments and has advantage of simplifying robot's hardware and software by distributing the complicated functionality of robots to other system. In this paper, we propose SOWL, which is a software architecture for URC robots and a mixed word of SOMAR and CAWL. SOWL keeps the advantages of URC and it also has the loosely-coupled characteristics. Moreover it makes it easy to develop of URC robot software. The proposed architecture is composed of 4 layers: device software, robot software, robot application, and end user layer. Developers of the each layer is able to build software suitable for their requirements by combining software modules in the lower layer. SOWL consists of SOMAR and CAWL engine. SOMAR, which is a middleware for the execution of device software and robot software, is based on service-oriented architecture(SOA) for robot software. CAWL engine is a system to process CAWL which is a context-aware workflow language. SOWL is able to provide a layered architecture for the execution of a robot software. It also makes it possible for developers of the each layer to build module-based robot software.