• Journal of Biomedical Engineering Research
• /
• v.40 no.5
• /
• pp.143-150
• /
• 2019

To evaluate the toxicity of ophthalmic drug, the Draize test and Bovine Corneal Opacity and Permeability (BCOP) test commonly used. In Draize test, experimental animals were under stress and pain due to long-term exposure of drug. In addition, regarding physiological functions, animal model is not perfectly reflected a human eye condition. Although some models such as $EpiOcular^{TM}$, HCE model, LabCyte Cornea-Model, and MCTT $HCE^{TM}$ were already presented advanced cornea ex-vivo model to replace animal test. In this sense, cornea tissue structure mimicked ex-vivo toxicity model was fabricated in this study. The corneal epithelial cells (CECs) and keratocytes (CKs) isolated from rabbit eyeball were seeded on non-patterned silk film (n-pSF) and patterned silk film (pSF) at $32,500cells/cm^2$ and $6,500cells/cm^2$. Sequentially, n-pSF and pSF were stacked to mimic a multi-layered stroma structure. The thickness of films was about $15.63{\mu}m$ and the distance of patterns was about $3{\mu}m$. H&E stain was performed to confirm the cell proliferation on silk film. F-actin of CKs was also stained with Phalloidin to observe the cytoskeletal alignment along with patterns of the pSF. In the results, CECs and CKs were shown the good cell attachment on the n-pSF and pSFs. Proliferated cells expressed the specific phenotype of cornea epithelium and stroma. In conclusion, we successfully established the ex-vivo cornea toxicity model to replace the eye irritation tests. In further study, we will set up the human ex-vivo cornea toxicity model and then will evaluate the drug screening efficacy.

• The Journal of the Korea Contents Association
• /
• v.5 no.5
• /
• pp.92-99
• /
• 2005

It is not easy to understand that the drama with various aspects of political-economics and psychology in a certain popular cultural contents. People, however, does want to reconstruct the meaning of the real world and the hyper - reality, it means cross of oldness and newness, through the films. We try to analyze in religious/philosophical aspect with hybrid narrative, characters and condensed meaning in series. This try shows a good example way of understanding series which on the border line of newness and oldness.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1403-1406
• /
• 2002

Environmental impact of human activities has become a great concern in most of the countries world-wide, and for years. It has recently focused on potential climate changes due to the increase of green house gases content in the atmosphere. One of these gases is $SF_6$, which is an essential material in electrical applications having excellent dielectric and arc-quenching properties. Though the actual contribution of $SF_6$ to global warming is negligible at present, the control of $SF_6$ emissions seems to be nevertheless imperative. Actually, it is listed in the Kyoto protocol that emissions should not only be duly reported but also the electrical industry which is now the major user of this gas must be able to show that it is possible to use this gas and at the same time preserve the environment. For the development of environmentally-benign electric power equipment and systems, novel gases or gas mixtures are strongly required as the alternatives of $SF_6$ gas. Until now, most research work is focused on the $SF_6/N_2$ mixed gas which is suitable for application in the electrical apparatus with slightly non-uniform fields. Recently, $SF_6/CO_2$ mixed gas also is expected to be promising as a $SF_6$ alternative, especially in highly non-uniform fields and in a gas-impregnated film insulation system. Including these results, the author reviews the research trend or reducing the environmental impact of $SF_6$ gas in this paper.

• Polymer(Korea)
• /
• v.38 no.1
• /
• pp.54-61
• /
• 2014

Water-soluble sulfobetaine chitosan (SCs) was prepared for a blending film with Bombyx mori silk fibroin (SF) by reacting chitosan with 1,3-propanesultone. A series of SF/SCs blended films were successfully prepared by mixing aqueous solutions of B. mori SF and SCs. The SF/SCs blended films were examined through spectroscopic and thermal analysis to determine the morphological changes of SF in the SCs. The effects of the SF/SCs blend ratios on physical and mechanical properties were investigated to discover the feasibility of using these films as biomedical materials such as artificial skin and wound dressing. X-ray analysis showed good compatibility between the two biopolymers. The in vitro degradation behavior of the SF/SCs blended films was systematically investigated for up to 8 weeks in phosphate buffered saline solution at $37^{\circ}C$ and showed a mass loss of 46.4% after 8 weeks. All films showed no cytotoxicity by MC3T3-E1 assay. After 3 days of culture, the relative cell number on all the SF/SCs films was slightly lower than that of an optimized tissue culture plastic.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.21 no.6
• /
• pp.230-234
• /
• 2011

High density plasma etching of ZnO film was performed in $CF_4$/Ar and $SF_6$/Ar inductively coupled plasmas. Maximum etch rates of ~1950 ${\AA}$/min and ~1400 ${\AA}$/min were obtained for $10CF_4$/5Ar and $10SF_6$/5Ar ICP discharges, respectively. The etched ZnO surfaces showed better RMS roughness values than the unetched control sample under most of the conditions examined. In the $10CF_4$/5Ar ICP discharges, very high etch selectivities were obtained for ZnO over Ni (max. 11) while Al showed etch selectivities in the range of 1.6~4.7 to ZnO.

• The Journal of the Korea Contents Association
• /
• v.13 no.10
• /
• pp.160-169
• /
• 2013

The materials used in the title sequence connotes a style & a content of film comprehensively. Therefore, the effect of emotional expression can be changed according to what materials are selected. Thus, the materials of which 42 title sequences are collected for the last 10 years are classified, and the category of materiality & material degree are defined with the semiotic rectangle. To investigate intensity of the material degree, the survey was done. As a result of the survey, the intensity was classified into 3 levels of material degree. The category of materiality used according to the genre of film was analyzed. As a result of the analysis, the materiality was selected according to the content regardless of genre, but there's any difference in the material degree. The intense material degree was used in a thriller and an SF mystery genre, and the medium one was used in the general genre, but, above all, drama and action genre. The weak one was used in a variety of genre, but specifically horror, SF mystery genre. It is significant that this study suggested the expression method in accordance with selection of materials in producing a title sequence to visualize film symbolically.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.105-108
• /
• 1995

The inter-metal dielectric SiOF films were fabricated using remote plasma-enhanced chemical vapour deposition with addition of SF$\sub$6/ gas. SiOF bond formation in these films was recognized by a chemical bonding structural study using FT-IR. The deposition rate and the dielectric constant of a deposited films were decreased with increasing SF$\sub$6/ gas. It was observed that leakage current of SiOF film was reduced the one order compared to a film without addtion of SF$\sub$6/ gas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.29-32
• /
• 1999

$GaF_3$ films were directly grown on p' and p-type GaAs(100) substrates using a $SF_6$ plasma discharge system. GaAs MIS(Meta1-Insulator-Semiconductor) capacitor was successfully fabricated for about 1 hour at temperature $290^{\circ}C$ using the as-grown $GaF_3$ films. The as-grown films on p'-GaAs exhibited a current density of less than 6.68 $\times$ $1O^{-9}$ A/$cm^2$ at a breakdown field of 500kV/cm and a refractive index of 2.0 ~ 2.3 at a wavelength of 632.8 nm. The dielectric constant was about 5 derived from 1 MHz capacitance-voltage (C-V) measurements. Dielectric dispersion of the fluoridated films on p'-GaAs measured ranged from 100 Hz to 10 MHz was not observed.

• Proceedings of the Korea Contents Association Conference
• /
• 2014.06a
• /
• pp.391-392
• /
• 2014

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.12
• /
• pp.935-938
• /
• 2011

The etching characteristics of ZnO and etch selectivities of ZnO to $SiO_2$ in $SF_6$/Ar plasma were investigated using Inductively-coupled-plasma (ICP). The maximum etch rates of ZnO were 6.5 nm/min at $SF_6$(50%)/Ar(50%), Source power (700 W), Bias power (250 W), Working pressure(8 mTorr). The etch rate of ZnO showed a non-monotonic behavior with increasing from 0% to 50% Ar fraction in $SF_6$/ Ar plasma. The plasma diagnostic were characterized using Optical Emission Spectroscopy (OES) analysis measurements.