Reconstruction of Rabbit Corneal Epithelium on Lyophilized Amniotic Membrane Using the Tilting Dynamic Culture Method

Ahn, Jae-Il,Lee, Doo-Hoon,Ryu, Yang-Hwan,Jang, In-Keun,Yoon, Mun-Young,Shin, Youn Ho,Seo, Young-Kwon,Yoon, Hee-Hoon,Kim, Jae-Chan,Song, Kye-Yong,Yang, Eun-Kyung,Kim, Ki-Ho,Park, Jung-Keug Blackwell Publishing Inc 2007 Artificial Organs Vol.31 No.9

<P>Abstract: </P><P>Rabbit corneal epithelium was reconstructed using tilting dynamic culture with a self-manufactured, amniotic membrane (AM) supporter and a lyophilized amniotic membrane (LAM). Rabbit corneal epithelial (RCE) cells were cultured and cryopreserved after isolation from the limbus. The second- and third-passage RCE cells were plated onto the epithelial side of the LAM of Ahn's AM supporter. Two days later, the air–liquid interface culture was maintained with third-passage RCE cells for 6 days and second-passage corneal epithelial cells for 9 days. The average viability of thawed RCE cells, assessed using trypan blue dye exclusion, was 77.42%. The reconstructed corneal epithelium was characterized by histological (hematoxylin and eosin) and immunohistochemical staining (proliferating cell nuclear antigen) for light microscopy, and by reverse transcriptase-polymerase chain reaction, glucose assay, and transmission electron microscopy. The basal layer of the reconstructed corneal epithelium was well formed, and the epithelium was tightly constructed due to the increase in cell proliferation and differentiation caused by the tilting dynamic culture, as opposed to static culture. Tilting dynamic culture was useful for the reconstruction of the epithelium using easily damaged epithelial cells and resulted in more stratum cell layers. Moreover, cytokeratin (CK3) mRNA expression in tilting dynamic cultured third-passage RCE cells seeded onto AM was greater than in static cultured third-passage RCE cells. The morphology of the reconstructed corneal epithelium on LAM by tilting dynamic culture for 9 days resembled that of the skin epidermis. This was thought to be because the tilting dynamic culture not only accelerated the proliferation and differentiation of cells by physical or mechanical stimulation, but also ensured that the supply of medium was delivered to the basal cells more efficiently. Thus, the reconstruction of the corneal epithelium using LAM and tilting dynamic culture was considered to be a good in vitro model for autologous or allogeneic transplantation of corneal epithelium and skin epidermis in patients with damaged epithelia. </P>

인터넷 중독 청소년들의 정신병리 및 대처 방식

안영균(Young Kyun Ahn),신영철(Young Chul Shin),고복자(Bok Ja Koh),심진현(Jin Hyun Shim),김범조(Bum Jo Kim),이승민(Seung Min Lee),이길홍(Kil Hong Lee) 한국중독정신의학회 2005 중독정신의학 Vol.9 No.1

This study was conducted to investigate the differences in psychopathology and coping strategies among internet addictors, over users and non addictors in high school students. Subjects were 273 high school students in Seoul city. Self rating questionnaires included demographic data, Young’s Internet Addiction Scale, SCL-90-R, Beck Depression Inventory, Spielberger State-Trait Anxiety Inventory, and The Way of Coping Strategy. Subjects were classified into 3 groups (addiction, over use, non addiction) by Internet Addiction Scale score. Prevalence of internet addiction was 4.3% and male adolescents were more addictive than female. Students who were mainly involved with internet chatting or game showed higher internet addiction score. The addiction group and over use group showed higher level of somatization, obsession, interpersonal sensitivity, depression, anxiety, hostility, and paranoia than non-addicted group. Addiction group and over use group used passive coping strategies more frequently in the stressful situation than nonaddicted group. Also, the regression analysis for finding out causal factors that predicts internet addiction showed that emotion relieving strategy were important variable which predict internet addiction. Interpersonal sensitivity and emotion relieving coping strategy was important to predict addiction. This study showed that problematic internet use was closely associated with psychopathology and psychiatric comorbidity. And high interpersonal sensitivity and emotion relieving coping strategy were related with internet addiction in adolescence.

SM45C의 레이저 표면경화특성

신호준,유영태,안동규,임기건 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

Laser surface hardening is an effective technique used to improve the tribological properties and also to increase the service life of automobile components such as camshafts, crankshatfs, lorry brake drums and gears. High power CO₂ lasers and Nd:YAG lasers are employed for localized hardening of materials and hence are of potential application in the automobile industries. The heat is conducted rapidly into the bulk of the specimen causing self quenching to occur and the formation of martensitic structure. In this investigation, the microstructure features occurring in Nd:YAG laser hardening SM45C steel are discussed with the use of optical microscopic and scanning electron microscopic analysis. Moreover, This paper describes the optimism of the processing parameters for maximum hardened depth of SM45C steel specimens of 3mm thickness by using CW Nd:YAG laser. Travel speed was varied from 0.6m/min to 1.0m/min. The maximum hardness and case depth fo SM45C steel are 780Hv and 0.4mm by laser hardening.

AC Impedance法에 의한 內燃機關用 耐熱·耐蝕材料의 耐蝕性 評價

안태수,백신영 木浦海洋大學校 1998 論文集 Vol.6 No.2

In the study the AC Impedance Method is applied to the checking Anti-corrosion behavior of Heat and Corrosion resistance material for Internal Combustion Engine. The obtained results are as follows : 1. The results of Potentio-dynamic Polarization for the Ni base Nimonic 80A, Fe base 304 stainless and Ti base Ti-6Al-4V indicated that Ecor is -100mV, -250mV and +200mV, ?? is 0.8μA/㎠, 3.0μA/㎠ and 0.8μA/㎠, ?? is 250mV, 240mV and 1,300mV respectively. 2. the passive film resistance by AC Impedance Test for the above mentioned Materials are 135Ω, 105Ω and 145Ω respectively. 3. Compare with Potentio-dynamic Polarization resistance and AC Impedance Methods, both are exhibited very similar result for corrosion resistance but AC Impedance Methods were delivered more information of total of Passive film, phase Shift, oxygen diffusion resistance. Which means that the AC Impedance Method will be used as more useful tool for Corrosion Study than Polarization methods.

고출력 레이저에 의한 이종금속 용접특성

신호준,유영태,임기건,안동규 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

For many years and primarily for economical reasons, Dissimilar Metal Welds have been used as transition joints in a variety of equipment and applications. But Dissimilar Metal Welds have several fabrication and metallurgical drawbacks that can often lead to in-service failures. In this paper, the laser weldability of STS304 stainless steel and SM45C at dissimilar metal welds using a continuous wave Nd:YAG laser are experimentally investigated. An experimental study was conducted to determine effects of welding parameters, on eliminating or reducing the extent welding zone formation at dissimilar metal welds and to optimize those parameters that have the most influence parameters such as focus length, power, beam speed, shielding gas, and wave length of laser were tested.

A Comparison of Lyophilized Amniotic Membrane with Cryopreserved Amniotic Membrane for the Reconstruction of Rabbit Corneal Epithelium

Ahn Jae-Il,Jang In-Keun,Lee Doo-Hoon,Seo Young-Kwon,Yoon Hee-Hoon,Shin Youn-Ho,Kim Jae-Chan,Song Kye-Yong,Lee Hee-Gu,Yang Eun-Kyung,Kim Ki-Ho,Park Jung-Keung The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Many researchers have employed cryopreserved amniotic membrane (CAM) in the treatment of a severely damaged cornea, using corneal epithelial cells cultured on an amniotic membrane (AM). In this study, two Teflon rings were made for culturing the cells on the LAM and CAM, and were then used to support the AM, which is referred to in this paper as an Ahn's AM supporter. The primary corneal epithelial cells were obtained from the limbus, using an ex-plantation method. The corneal epithelium could be reconstructed by culturing the third­passage corneal epithelial cells on the AM. A lyophilized amniotic membrane (LAM) has a higher rate of graft take, a longer shelf life, is easier to store, and safer, due to gamma irradiation, than a (AM. The corneal epithelium reconstructed on the LAM and (AM, supported by the two­Teflon rings, was similar to normal corneal epithelium. However, the advantages of the LAM over that of the (AM make the former more useful. The reconstruction model of the corneal epithelium, using AM, is considered as a good in vitro model for transplantation of cornel epithelium into patients with a severely damaged cornea.

ATM망에서 비율적 대역할당을 이용한 혼잡제어 알고리즘

신영미,안기중 濟州大學校工科大學産業技術硏究所 1999 尖端技術硏究所論文集 Vol.10 No.1

In this paper, ER-based traffic control algorithm is proposed to offer ABR service efficiently according to the request of ABR traffic service in ATM Networks. It is necessary to add function mediating a transmission rate of VC unit in order to efficiently apply VC link for users' QoS requirements. Accordingly, a proposed method means to calculate bandwidth with the FairShare value based on PCR of each ABR VC according to the available bandwidth of networks, and to regulate traffic. It is shown that the algorithm proposed with the simulation results is more excellent than an established ERICA algorithm in view of allotting suitable bandwidth to traffic feature, and link usage.

청소년 비행 예방을 위한 여가활동 프로그램 개발

신영균,안영필 東亞大學校附設스포츠科學硏究所 1996 스포츠科學硏究論文集 Vol.14 No.-

These are focused on the investigation for the Youth's healthy leisure activities on the participation. Program development of Youth's leisure activities for prevent irregularity through setting up the sound leisure culture. In order to for these themes this study suggest that; 1) It is necessary that organize program for mind and body's harmonious development of youth's who are growing. 2) Sport for all programs must contain the ability of forming memberships and preventing irregularly deviation. 3) These programs must contribute for creative leisure activities and human development. 4) These programs must be interesting in order to minimize youth's irregularly contact. 5) These programs must contains ability of cleaning up the disadaptable activities caused on competitive society of psychology. 6) leisure actives must make youth to have dreams and ambitions. 7) These programs must be composed of valuable program to make youth to apply educational capacity with preventing safety accident.

ATM망에서 비율적 대역할당을 이용한 혼잡제어 알고리즘

신영미,안기중 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.1

In this paper, ER-based traffic control algorithm is proposed to offer ABR service efficiently according to the request of ABR traffic service in ATM Networks. It is necessary to add function mediating a transmission rate of VC unit in order to efficiently apply VC link for users' QoS requirements. Accordingly, a proposed method means to calculate bandwidth with the Fairshare value based on PCR of each ABR VC according to the available bandwidth of networks, and to regulate traffic. It is shown that the algorithm proposed with the simulation results is more excellent than an established ERICA algorithm in view of allotting suitable bandwidth to traffic feature, and link usage.

청소년의 선수 경험과 비행과의 관계

안영필,신영균,조만태 東亞大學校 附設 스포츠科學硏究所 1997 스포츠科學硏究論文集 Vol.15 No.-

The purpose of this study is to clarify the realationship between the athletic player and deliquency. In order to clarify this purpose, the following subsequent research questions were analysed and these were : deliquent contact, future stress, social circumstance, home circumstance, fatigue, spores socialization and deliquent degree. The subjects of this study were selected in junior high schools and high schools in Pusan. The number of subjects were 364(athletic player experienced students:139, non-athletic experienced students:364). Based on the procedures and results, the folling conclusions were warranted : 1. The realationship between athletic player experienced group and non-athletic player group ad much differences in fatigue. 2. The realationship between realated factor and socialization by sports participation had much similiarity in both group. By this conclusions, students like to participate sports activities and think value of sports participation important. 3. Athletic player experienced group(M=3.71) was higher than non-athletic player experienced group(M=3.48) in deliquent contact by mean of realated factor difference of the two groups. 4. Athletic player experienced group(M=3.54) was higher than non-athletic player experienced group(M=3.03) in solution of future stress by mean of realated factor difference of the two groups. Considered of this, athletic player experience take good influences in solution of future stress. 5. The realationship between two groups had no difference in recognizing of social cirsumstance by mean of realated factor difference of the two groups. 6. Athletic player experienced group(M=2.92) is higher than non-athletic player experienced group(M=2.73) in satisfaction of home circumstance by mean of realated factor difference of the two groups. 7. Athletic player experienced group(M=2.92) is higher than non-athletic player experienced group(M=2.49) in solution of fatigue on sports participation by mean of realated factor difference of the two groups. 8. Athletic player experienced group(M=3.40) think value of sports socialization more inportant than non-athletic player experienced group(M=3.13) by mean of realated factor differencde of the two groups. 9. Athletic player experienced group(M=2.68) is higher than non-athletic player experienced group(M=2.44) in value of sports socialization on sports participation by mean of realated factor difference of the two groups. 10. Between two groups, deliquent contact, future stress, fatigue, sports socialization and deliquent degree had 1% similiarity, home circumstance had 5% and social circumstance had no similiarity.