• Parasites, Hosts and Diseases
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• v.38 no.2
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• pp.99-102
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• 2000

In order to observe the cytotoxicity of Acanthamoeba spp., which were isolated from contact lens containers as ethiological agents for the probable amoebic keratitis in Korea, the crystal violet staining method and LDH release assay were carried out. In the crystal violet staining method, among eight contact lens container isolates, isolate 3 (Acanthauloeba KA/LS5) showed 83.6% and 81.8% of cytotoxicity, and isolate 7 (Acanthamoeba KA/LS37) showed 28.2% and 25.1% of cytotoxicity, in 1 mg/ml and 0.5 mg/ml Iysate treatments, respectively. Acanthamoeba cutbertsoni and A. healyi showed 84.0% and 82.8% of cytotoxicity. Similar results were observed in A. costellunii and A. hafchefti which showed 83.6% and 75.5% or cytotoxicity. Acanthamoeba roureba and A. polyphaga showed 9.0% and 1.7% of cytotoxicity. In the LDH release assay, isolate 3 (20.4%) showed higher cytotoxicity than other isolates in 1 mg/ml Iysate treatment. The results provide that at least isolate 3 has the cytotoxic effect against CHO cells and seems to be the pathogenic strain.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.553-560
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• 2018

Purpose : To investigate a disposal method of disposing contact lenses and the recognition of environmental pollution by micro plastics which may be caused by the wrong disposal method of domestic contact lens wearers. Methods : Two hundred sixty one adults(124 males, 137 females, mean age $21.48{\pm}3.14years$) were participated in this study. They were given the questionnaire survey on contact lenses purchasing place, type of contact lenses, duration of wearing contact lenses, the disposal method of disposing contact lenses and the recognition of the occurrence of environmental pollution. Results : It appeared that eyeglass shop(50.0%) and contact lens shop(48.3%) were the main purchasing places, and the most common type of contact lenses were disposable lenses(38.5%) and daily wearing lenses(52.5%). On the duration of wearing contact lenses they answered more than 5 years(29.3%), less than 1 year (26.0%), less than 1 year to less than 3 years (26.0%), and on wearing a contact lens during a week they did 1-2 days (32.0%), 1 week (28.0%), 5-6 days (22.4%) and 3-4 days (17.6%). It was shown "no(78.3%)" and "yes(21.7%)" to the questionnaire of whether they received information or education about a disposal method at the place where the contact lens was purchased, and "no(87.5%)" and "yes(12.5%)" to the questionnaire of whether they received information or education from schools, public institutions or public media such as the internet. As for the disposal methods, landfill waste(45.6%), recycled garbage(29.6%), and drainage(16.8%) from the sink or toilet responded in order. Although men were more educated and informed about disposal than women (t=3.63189, p<0.00001), women were more aware of environmental pollution(t=2.44269, p=0.01605). Conclusion : In order to reduce the environmental pollution issue caused by the contact lens which does not decompose at the sewage treatment facility and become micro plastics, it is urgent to provide information about correct disposal methods after using contact lenses and to educate contact lens wearers.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.207-212
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• 2010

Purpose: Rigid gas permeable (RGP) contact lenses, based on fluorosilicone acrylate, were treated with plasma in air. Methods: The chemical compositions were analyzed by using X-ray photoelectron spectroscopy (XPS), the surface morphology and roughness of RGP contact lenses were observed by using atomic force microscopy (AFM), and the wettability changes were estimated by wetting angle measurement. Results: As the contact lenses were treated by the plasma, the F contents decreased significantly, and the O and Si contents increased on the surface. The number of oxygen-containing hydrophilic radicals (C-O and Si-O) increased greatly, the hydrophobic surface decreased, and the wetting angle increased. But the C-O bonds created with exchange of the fluorine did not increase a wettability. The surface compositions were not remarkably changed for the 6 months after plasma treatment, but the wetting angle increased again. Conclusions: It was considered that the improved wettability of the RGP contact lenses of high fluorine content after plasma treatment was affected by the activation of surface, the increase of Si-O, and the decrease of hydrophobic surface.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.37-41
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• 2007

The aim of this study is to establish RGP lens care system using RGP lens multi-purpose solution(MPS) and cleaner. Each RGP lens was incubated in Pseudomonas aeruginosa standard strain, and the numbers of P. aeruginosa colony remaining after treatment by using MPS and/or cleaner including surface activating components were estimated. Soaking only in MPS for 30 min reduced the number of P. aeruginosa up to 50%. 95% of P. aeruginosa was eliminated at RGP lenses soaked in MPS for 4 hr, but P. aeruginosa was not detected at RGP lenses soaked for 6 hr. When only cleaner was used for RGP lens care, 70% of P. aeruginosa was eliminated. This result showed that using cleaner had more effective at removing P. aeruginosa than soaking in MPS for 30 min. When soaking in MPS for 30 min after using cleaner reduced the number of P. aeruginosa up to 36% of that which soaking only in MPS for 30 min. This result suggested that using cleaner could be helpful to improve the disinfection efficacy of short time soaking in MPS.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.467-473
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• 2019

In this study, approached to improve durability of the multi-functional nano-pattern fabricated on the curved lens surface using nanoimprint lithography (NIL) was proposed, and the effects of the proposed methods on functionality after wear test were examined. To improve the mechanical property of ultraviolet(UV)-curable resin, UV-NIL was conducted at the elevated temperature around $60^{\circ}C$. In addition, micro/nano hierarchical structures was fabricated on the lens surface with a durable film mold. Analysis on the worn surfaces of nano-hole pattern and hierarchical structures and measurements on the static water contact angle and critical water volume for roll-off indicated that the UV curing process with elevated temperature is effective to maintain wettability by increasing hardness of resin. Also, it was found that the micro-scale pattern is effective to protect nano-pattern from damage during wear test.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.204-204
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• 1999

The plasma source ion implantation(PSII) technique which is a method using high negative voltage pulse in plasma system has the potential to change the surface properties of polymer. PSII technique increase the surface free energy by introducing polar functional groups on the surface so that it improves reactivity, hydrophilicity, adhension, biocompatability, etc. However, the mobility of polymer chains enables the modified surface layers to adapt their composition to interfacial force. This hydrophobic recovery interrupts the stability of modified surfaces to keep for the long time. In this study, poly(methyl methacrylate)(PMMA), poly(2-hydroxyethyl methacrylate)(PHEMA), and polu(2-hydroxypropyl methacylate)(PHPMA) for contact lens application, were modified to improve the wettability with PSII technique and were investigated the surface stabilities. Polymer film was prepared with solution casting(3 wt.% solution) and was annealed at 11$0^{\circ}C$ under vacuum oven to remove solvent completely and to eliminate physical ageing. The thickness of the film measured by scanning electron microscopy (SEM) and surface profilometer was about 10${\mu}{\textrm}{m}$. Polymers were treated with different kinds of gases, pulse frequency, pulse with, pulse voltage, and treatment time. Even though PMMA, PHEMA, and PHPMA have similar repeat unit structure, the optimal treatment conditions and the tendency to hydrophobic recovery were different. PHPMA, more hydrophilic polymer than PMMA and PHEMA showd better wettability and stability after mild treatment. Surface tensions were obtained by water and diiodomethane contact angle measurements to monitor the relation between hydrophobic recovery and polymer structure. Different ion species in plasma change the polar component and dispersion component of polymer surface. For better wettability surface, the increase of polar component was a dominant factor. We also characterized modified polymer surfaces using x-ray photoelectron spectroscopy(XPS), secondary ion mass spectrometry(SIMS), Fourier Transform infrared spectroscopy(FT-IR), and SEM.

• Journal of Korean Clinical Health Science
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• v.8 no.1
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• pp.1386-1397
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• 2020

Purpose: To examine the effectiveness of various treatments; bifocal spectacles, orthokeratology, atropine, and time spent in outdoors; in slowing down the myopia progression for Asian adolescents (6-18age). Methods: The research focused on examining the most effective treatment in controlling myopia based on the literature sources that have been published. Through meta-analysis of various research papers that already has been done in this field, a lot of data was collected. For each treatment, the difference in axial length and spherical equivalent over time was measured and recorded. To quantitatively record the difference, both axial length and spherical equivalent was determined by value of control group value of treatment group. The paper compared the effectiveness of each treatment based on the data that was measured. Results: Adolescents who chose to spend time outdoors in order to slow down myopia progression had axial length difference of 0.03 mm and spherical equivalent difference of 0.17 D. Adolescents that used atropine had axial length difference of 0.36 mm and spherical equivalent difference of 0.92 D. Bifocal spectacle resulted in axial length difference of 0.21 mm and spherical equivalent difference of 0.59 D, and for orthokeratology 0.23 mm and 0.04 D, respectively. Axial length wise, myopia was most controlled by the atropine since there was a greatest difference between the group that got the treatment and the group that did not have the treatment. According to the spherical equivalent difference data, myopia was most controlled by atropine. Conclusion: Atropine showed the most effective result in controlling myopia among the four treatment. Again, compared to other three treatment, using atropine appeared to have greatest ability in slowing down myopia progression since adolescents who were treated with atropine had greatest difference from adolescents in the control group that had the same condition but didn't get the treatment. However, every treatment was only used for 2 or 3 years which is quite short time period to measure the long term effect of the four treatments. Also, since atropine is a pharmaceutical method to control myopia, it may harm adolescents' eyes compared to optical or environmental treatment.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.19-25
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• 2007

It was studied how using soft contact lens multi-purpose solution (MPS), often used for medical treatment, effects the inhibition on cell growth, and how using the MPS demages eye cells, on rabbit eye's corneal epithelium and endothelium tissue. $ReNu^{(R)}$ (Baush & Lomb, USA), Opti-free $express^{(R)}$ (Alcon, USA), Free-sol $plus^{(R)}$ (Hanamedicon, Korea) were used as MPS. After culturing Clone 1-5C-4 cell lines (Human conjunctival cell lines), cell growth inhibition rate was measured by MIT assay. By making Hematoxylin and Eosin stain specimen, the morphology was observed by optical microscope. In the In vivo experiment, 9 white rabbit eyes (18 eyes) were classified into 3 groups. The experiment group is left eyes (9 eyes) of rabbit, and MPS were dropped; however the control group, the right eyes (9 eyes), were only used a saline solution without a preservatives. After the dropping within the period, the cornea surface of rabbit endothelium tissue was observed using scanning electron microscopy (SEM).

• Applied Microscopy
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• v.36 no.3
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• pp.141-153
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• 2006

The purpose of this study is to find out how soft contact lens multi-purpose solution (MPS), often used for medical treatment, effects the inhibition on cell growth and research the result of using MPS, suspected to demage eye cells, on rabbit eye's corneal epithelium and endothelium tissue. In this treatise, $ReNu^{(R)}$ (Baush & Lomb, USA), Opti-free $express^{(R)}$ (Alcon, USA), Free-sol $plus^{(R)}$ (Hanamedicon, Korea) had been selected among the MPS. After culturing L929 roil line, cell growth inhibition rate was measured by MTT assay, and by making Hematoxylin and Eosin stain specimen. the morphology was observed by optical microscope. In the In vivo experiment,9 white rabbit eyes (18 eyes) were classified into 3 groups. The experimental group is left eyes (9 eyes) of rabbit, and MPS were dropped; however. the control group, the right eyes (9 eyes), were only used a saline solution without preservatives. After the dropping within the period, the cornea surface of rabbit eyes were stained by Rose bengal and observed. To figure out the changes of the corneal epithelium and endothelium tissue scanning electron microscopy (SEM) has been used. As the result, the rate of cell growth inhibition was 54%. 73% and 36%, respectively. Morphological changes represented that the shape has been changed into oval or round shape and those are not considered as a common formation of L929 cell line. When it comes to staining Rose bengal, each experiment group was stained red which is not shown in controls. The polygonal mosaic pattern of a corneal epithelium was disturbed in the picture taken by SEM; furthermore, the shape of the corneal endothelium was irregular. In conclusion, as we consider antimicrobial effect and the safety on living cells, it is necessary that we should improve concentration of preservatives and study continuously to develop a new preservatives without a toxic effect on the cornea surface.

• Journal of Korean Academy of Nursing
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• v.29 no.4
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• pp.802-816
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• 1999

The purposes of this research were to identify nursing interventions performed by Korean nurses and to compare the interventions performed by nurses working in the oriental medicine hospitals and with those performed by nurses working in the general hospitals. The samples consisted of 144 Korean nurses working in three hospitals, 70 nurses working in the oriental medicine hospitals and 74 nurses working in the general hospitals. The Nursing Interventions Classification (NIC) Use Questionnaire developed by the Iowa Intervention Project team was translated to Korean and verified using the method of back-translation. The questionnaire consists of 433 intervention labels and definition. Thirteen interventions were used at least daily by nurses working in the oriental medicine hospitals, while twenty-one interventions were used at least daily by nurses working in the general hospitals. The most frequently used interventions by nurses working in the oriental medicine hospitals were Documentation, Shift Report Vital Signs Monitoring, Pressure Ulcer Prevention, Positioning, Fall Prevention, Exercise Promotion, Intravenous (IV) Therapy, Pressure Ulcer care, and Bed Rest Care in that crder. For nurses working in the general hospitals the most frequent intervention was Analgesic Administration, followed by the interventions of Medication Administration : Parenteral and Intravenous Therapy (IV) Therapy, Documentation, Intravenous(IV) Insertion, Shift Report, Fall Prevention, Vital Signs Monitoring, Medication Adnninistraction : and, Fluid Monitoring, and Medication Maragement in that order. The interventions performed least often by nurses working in the oriental medicine hospitals were Hemodialysis Therapy and Bleeding Reduction : Antepartum Uterus, while the interventions performed least often by nurses working in the general hospitals were Rape Trauma Treatment and Contact Lens Care. The nurses working in the oriental medicine hospitals performed the interventions in the Physiological : Complex domain significantly more often than the nurses working in the general hospitals, while the nurses working in the general hospitals performed the intervention in the Behavior domain significantly more often than the nurses working in the oriental medicine hospitals. This study suggests that further study will be needed to developed and validate more interventions sensitive to Korean culture.