• 한국재료학회지
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• 제24권6호
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• pp.310-318
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• 2014

In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and N-Hydroxysuccinamide (EDC-NHS). The initial average pore size of the scaffold ranged from 300 to $700{\mu}m$, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1 pre-osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCP-BG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater (geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2021-2026
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• 2011

AgNPs (silver nanoparticles) has been widely used for the commercial products, which have antimicrobial agent, medical devices, food industry and cosmetics. Despite, AgNPs have been reported as toxic to the mammalian cell, lung, liver, brain and other organs and many researchers have investigated the toxicity of AgNPs. In this study, we investigated toxicity of the AgNPs to the liver cell using metabolomics based on HRMAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) technics, which could apply to the intact tissues or cells, to avoid the sample destruction. Target profiling and multivariative statistical analysis were performed to analyze the 1D $^1H$ spectrum. The results show that the concentrations of many metabolites were affected by the AgNPs in the liver cell. The concentrations of glutathione (GSH), lactate, taurine, and glycine were decreased and most of amino acids, choline analogues, and pyruvate were increased by the AgNPs. Moreover, the levels of the metabolites were recovered upto similar level of metabolites in the normal cell by the pre-treatment of NAC, external antioxidant. The results suggest that the depletion of the GSH by the AgNPs might induce the conversion of lactate and taurine to the pyruvate.

• 보건교육건강증진학회지
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• 제16권1호
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• pp.137-148
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• 1999

The necessity of school health promoting projects is well known to many researchers, however, there is a lack of research on the development of strategies for school health programs and the evaluation of the effectiveness of the programs. The results of our previous study in 1996 identified poor eyesight as one of the several health problems among elementary school children in urban areas. The main objective of this study is to develop, implement, and evaluate vision care for elementary school children. The research method utilized a quasi experimental design using non-equivalent group, pre-post comparison. The sample consisted of all second grade children in two elementary schools in Kyung-giProvince. In order to prevent a contamination effect of the vision care program, one school was selected as a control and the other school was selected as a treatment group. The experimental school had 467 children and the control school had 402 children. The visual acuity of children in both group was measured and a survey questionnaire was sent out to parents on the knowledge, attitude, and behavior related to vision care before the program was implemented. The children of the experimental school received the following programs; separate education on proper nutrition and care of eyesight for children and parents, daily eye exercises using video tape, and an essay and poster contest on healthy eyesight. The eye exercise program lasted from March, 1997 to November, 1997. On November, 1997, visual acuity was measured again from children in both schools. The data was analyzed by using SAS statistical package. The results indicate that the children in the experimental group had significantly (p〈0.001) better eyesight than the children in the control group. Also, some of the behavior highly related to the poor eyesight are poor maternal eyesight and watching TV from a short distance. In conclusion, one of the significance of this project is that the vision care program was developed after the need assessment. It will be encouraged in the future that more school health program should be developed after a need assessment. Also, inclusion of family members was important in health promoting projects within a school setting since healthy behavior needs to be reinforced at horne as well as at school.

• 임상간호연구
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• 제18권1호
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• pp.126-135
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• 2012

Purpose: This study was aimed to develop a simulation training program of an advanced cardiac life support (ACLS) based on the mastery learning model (Simulation-MLM), and evaluate the effects of the program on critical care nurses. Methods: As an experimental pre-post test with a non-equivalent control group, the study employed convenience sampling of 38 critical care nurses. The experimental group received the Simulation-MLM including a theoretical lecture, formative evaluation, and simulation training, whereas only a theoretical lecture for the control group. The knowledge, self-efficacy, and performance degrees of respondents were measured to verify the effects of the Simulation-MLM. The statistical processing of the collected data utilized the SPSS WIN 17.0 program. Results: After receiving Simulation-MLM, the participants in the experimental group reported higher marks in the knowledge, self-efficacy and performance of ACLS compared with those in the control group. However, both experimental and control groups demonstrated no significant differences in knowledge, self-efficacy and performance. Conclusion: Despite of the limitation of a small sample size, this study was considered meaningful in a sense that it showed a venue for improving ACLS training efficiency. Future research with more distinct treatment differentiation and better adequate outcome variables was warranted in order to prove the effects of a theory-based simulation education.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.35-41
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• 2007

An International Convention on the control of harmful anti-fouling system on ships(AFS Convention) was adopted on 5 October 2001 at Diplomatic Conference in London, and is expected to be presently effectuated with ratification of more than 25-member nations possessing about 25% of total world tonnage. This convention regulates the operation of harmful anti-fouling system and especially prohibits the use of organotin compounds contained in anti-fouling paint. Organotin compounds have a tendency to be easily extracted by specific solvents and have high polarity and low volatility as specific characteristics. This drives us to attempt of going through the process named derivatization that is required in analysis using a gas chromatography(GC). This study was conducted to determine the proper pre-treatment method, ethylation in comparison with hydridization on the analysis of tributyltin in organotin compounds and to verify the application of the method through the experimental analysis practically used anti-fouling paint and painted layer sample of the served ship.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.139-141
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• 2005

It is possble to study charge transfer property which is caused by height variation because we can see the organic materials barrier height and STM tip by organic materials energy band gap. Here, we investigated the negative differential resistance(NDR) and charge transfer property of self-assembled 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene, which has been well known as a conducting molecule. Self-assembly monolayers(SAMs) were prepared on Au(111), which had been thermally deposited onto pre-treatment($H_{2}SO_{4}:H_{2}O_{2}$=3:1) Si. The Au substrate was exposed to a 1 mM/l solution of 1-dodecanethiol in ethanol for 24 hours to form a monolayer. After thorough rinsing the sample, it was exposed to a $0.1{\mu}M/1$ solution of 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene in dimethylformamide(DMF) for 30 min and kept in the dark during immersion to avoid photo-oxidation. After the assembly, the samples were removed from the solutions, rinsed thoroughly with methanol, acetone, and $CH_{2}Cl_{2}$, and finally blown dry with $N_2$. Under these conditions, we measured electrical properties of self-assembly monolayers(SAMs) using ultra high vacuum scanning tunneling microscopy(UHV-STM). The applied voltages were from -1.50 V to -1.20 V with 298 K temperature. The vacuum condition is $6{\times}10^{-8}$ Torr. As a result, we found that NDR and charge transfer property by a little change of height when the voltage is applied between STM tip and electrode.

• 대한가정학회지
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• 제41권11호
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• pp.135-150
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• 2003

This research was to verity the effects of ICT teaching method in high school home economics. The research questions for this study were as follows: 1. Is the ICT teaching method effective in increasing students' interest in home economics and consciousness on traditional culture in teaming the unit of ‘Korean traditional culture of home life’？ 2. Is the ICT teaching method effective in improving students' achievement test and performance assessment in teaming the unit of ‘Korean traditional culture of home life’？ This study is carried out with following procedure: developing the homepage and lesson plans for ICT teaching, constructing questionnaire, and testing its reliability, pre-testing, treatment for 8 weeks, and post-testing. Two groups were arranged for 8 weeks experiment from May 7,2001 through June 30,2001. Sixteen hours of ICT teaching and 8 hours of traditional lecture for experiment group whereas 8 hours of ICT teaching and 16 hours of traditional lecture for comparison group were input. SAS program was used for statistical analysis, and independent sample t-test and matched pairs t-test were peformed for answering research questions. The results of this study were as following: 1. Sixteen hours of ICT teaching and 8 hours of traditional lecture for experiment group was effective in increasing consciousness on traditional culture and performance assessment. 2. Eight hours of ICT teaching and 16 hours of traditional lecture for comparison group was not effective in learning home economics. This means that at least 2 hours of ICT teaching is demanding for effective learning. This study concluded that ICT teaching will be effectively applied in high school home economic with well developed ICT teaching materials. And home economics educators should continuously put effort in developing curricular, teaching materials, and teaching methods to raise students' interest in home economics.

• 한국응용과학기술학회지
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• 제22권4호
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• pp.306-314
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• 2005

In this study, spherical $pre-BaTiO_3$ particles are prepared by gelation and aging process in autoclave without catalysts. The (Ba-Ti) gel used as a starting material was prepared by aging mixtures of titanyl acylate with barium acetate aqueous solution([glacial acetic acid (AcOH)]/[titanium isopropoxide (TIP)] 4, [barium acetate]/[TIP] 1) at $45^{\circ}C$ for 48hrs. XRD and SEM results for the (Ba-Ti) gel sample at aging process showed that the gel was formed via aggregation of the fine particles. It seems to be the primary particles of bulk (Ba-Ti) gel amorphous, but the spatial arrangement of barium and titanium in the (Ba-Ti) gel is similar to that in crystalline $BaTiO_3$ particles. From XRD and FT-IR. spectroscopy analysis it was found that the crystal structure of the prepared particles continuously transformed from amorphous to tetragonal as the calcination temperature increased, and crystallized spherical cubic and tetragonal $BaTiO_3$ powder obtained at the very low calcination temperature between $500^{\circ}C$ and $900^{\circ}C$ after 1hrs of heat treatment respectively. According to BET analysis result, final particle have pore structure of ink bottle shape which is produced by aggregation of fine spherical particles with surface area of $280m^2/g$ and average pore size of 130nm.

• 대한수의학회지
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• 제39권4호
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• pp.730-737
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• 1999

A national animal health monitoring system(NAHMS) in Gyeongnam area was started from 1997 to develop statistically valid data for use in estimating disease frequencies in dairy cattle, and the associated costs. The objectives of this study were to : (1) discribe what was done to implement and maintain the system in Gyeongnam ; (2) present selected disease frequencies ; (3) discuss the epidemiological consideration of what was done and implications for the results obtained. Veterinary Medical Officers(VMOs-professors and graduate students from Gyeongsang National University, Faculty of Gyeongnam Livestock Promotion Institute, and Clinic veterinarians) served as data collectors. After training on current disease and management problems of dairy cattle, interview techniques, sampling methods, and data collection instruments, the VMOs participated in selection of the sample herds and data gathering. Forty of 167 dairy herds were selected randomly and the VMOs visited farms once a month for 12 months to collect data about management, disease, inventory, production, preventive treatment, financial and any other relevant data. Strict data quality control devices were used. Specific feed-back was developed for the producers and data collectors. Of the three age groups studied, cows had the greatest number of disease problems. The six disorders found most frequently were (from the highest to the lowest) breeding problems, clinical mastitis, birth problems, gastrointestinal problems. metabolic problems, and lameness. In young stock, respiratory, multiple system, breeding problems, and gastrointestinal problems were pre dominant, whereas in calves, gastrointestinal, respiratory, and integumental problems were major.

• 자원환경지질
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• 제30권3호
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• pp.223-230
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• 1997

The skeletal chemistry of calcareous microfossils may contribute to the classification of various biological processes and be used as an environmental indicator for future pollution. In order to examine the degree of heavy metal pollutions in marine environments, samples of sediment and benthonic foraminifera were taken from 5 study areas from 3 different stations in coastal offshore regions of Korea. After sieving, cleaning and acid digestion, sample were analyzed for heavy metals by ICP-MS, ICP-AES and AAS. Concentrations of Cd, Cu, Pb and Zn in most of marine sediments from 5 study areas are not higher than those in sediments from unpolluted marine environment in the U.K.. However, pollution indices are up to 0.96~0.99 in the Gwangyang and Yulchon areas which are classified as the special control distric along the coast for pollution. The pollution indices decrease in order of Yulchon > Gwangyang > Mokpo > Gamak = Yoja > Yonggwang areas. Concentrations of Mg, Pb, Sr and Zn in Ammonia beccarii Pseudorotalia gaimardii, Quinqueloculina lamarckiana are reduced after pre-treatment of samples. From the result of bioconcentration index, Mg is easily accumulated in microfossils and Quinqueloculina lamarckiana may be used as the best indicator for future pollution.