• Journal of the Korean Electrochemical Society
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• v.6 no.4
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• pp.229-235
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• 2003

A precursor of lithium manganese oxide was synthesized by mixing $(CH_3)_2CHOLi\;with\;Mn(CH_3COO)_2{\cdot}4H_2O$ in ethanol using a sol-gel method, then heat-treated at $400^{\circ}C\;and\;800^{\circ}C$ in air atmosphere. The condition of heat treatment was determined by thermogravimetric analysis/differential thermogravimetric analysis (TGA/DTA). The characterization of the lithium manganese oxide was done by X-ray diffraction (XRD) spectra and scanning electron microscopy (SEM). The electrochemical characteristics of lithium manganese oxide electrode for lithium ion battery were measured by cyclic voltammetry (CV), chronoamperometry and AC impedance method using constant charge/discharge process. The electrochemical behaviors of the electrode have been investigated in a 1.0M $LiClO_4/propylene$ carbonate electrolyte solution. The diffusivity of lithium ions, $D^+\;_{Li}\;^+$, as determined by AC impedance technique was $6.2\times10^{-10}cm^2s^{-1}$.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.115-130
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• 2009

Three experiments on the addition of Porous Calcium Silicate (PCS) to broiler feed were conducted at different time periods in the same house. Each treatment had 4 replicates with 12 chicks in each treatment. Weight gain and feed intake were higher ($P{\le}0.05$) in the control groups. Feed conversions' were better ($P{\le}0.05$) in the PCS group, 3.0% PCS and 20 mesh size of PCS than the control group from 21 to 49 days, and for the overall period. $NH_3$ and $H_2S$. gas production were decreased ($P{\le}0.05$) when zeolite was added in broiler feeds. 1.5% or 3.0% PCS in broiler feed was better ($P{\le}0.05$) than the 4% PCS. More than 90 mesh size PCS was better ($P{\le}0.05$) in controlling $CO_2$ production in the 5th period than the 20 or 50 mesh size or control groups. The control and PCS groups produced more flies ($P{\le}0.05$) than zeolite group during the 2nd and 3rd weeks. The 3.0% or 4.5% PCS or 50 or 90 mesh size of PCS in broiler feed produced more flies than the 20 mesh size or control groups although 50 or 90 mesh size of PCS during 5th week tended to have lower fly production than the 20 mesh size of PCS and control group.

• Women's Health Nursing
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• v.8 no.2
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• pp.289-300
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• 2002

The purpose of this study was to identify the perceptional difference of sexual image and sexual role between male and female students at the university level.. Questionnaires were collected from 418 students of H University in Kangwon-do, Korea from September to December 1999. The research tools were Sexual Image(Joo,1996, Cronbach's $\alpha$=.83) and Sexual Role (Chang,1989, Cronbach's $\alpha$=.93). Data were analyzed by SPSS-PC. The results of this study were as follows: According to factors of sexual image, the average score of sexual attitude was 3.06, that of sexual evaluation was 2.41, and that of sexual curiosity was 2.18, therefore university students had a high degree of curiosity but also had a relatively more exclusive image related to sexuality; there was a significant difference in sexual image between male and female students (t=10.99, p=0.010), male students were perceived to have a higher sexual curiosity and more positive sexual image than female students; the average score of sexual role was 2.21, that appeared to be a moderately progressive tendency; there was a significant difference in sexual role between male and female students (t=260.46, p=0.000), female students were apt to be more progressive in sexual role than male students. According to the above results, curriculum development and the application of at university would be necessary to develop and apply some liberal courses and workshop programs so that students and professors could prepare to identify ideal sexual roles and sexual images.

• Journal of the Korean Society of School Health
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• v.10 no.2
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• pp.285-295
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• 1997

This study was designed to identify the relation between Self-care Agency and mental health in vocational high school students of a rural area. The subjects for this study were 210 students living in Chonnam province: the breakdown of first, second and third grade students were 74, 78 and 58 respectively. The data were collected from April 1 to 4, 1997. The instruments used in this study were the Self-Care Agency Questionnaire developed by Deneys (1981) and the simplified SCL-90 developed by Lee, H. K. (1986) for measuring Mental Health. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation using the SAS $PC^+$ Program. The results were as follows: 1. The mean score of the Self-care Agency was 2.43. 2. The mean score of Mental Health was 2.11. 3. There were significant differences in sex (t=6.13, p= .014), religion (t=4.65, p= .032), the educational level of the father (F=3.62, p= .032), economic status (F=5.90, p= .003), and school performance (F=5.94, p= .003) with respect to selfeare agenecy. 4. There were significant differences in dwelling place (t=3.18, p= .025), economic status (F=4.55, p= .012), school performance (F=6.72, p= .002) and health problems (t= 5.41, p= .021) with respect to mental health. 5. The relationship between self care agency and mental health revealed a significant correlation (r=- .24, p= .005). The results showed that a low level of self care agency has an effect on mental health. We need an effective health education program to promote mental health.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.1
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• pp.37-47
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• 2023

A new clamped mechanical splice system was proposed to develop structural performance and constructability for precast concrete connections. The proposed mechanical splice resists external loading immediately after the engagement. The mechanical splices applicable for both large-scale rebars for plants and small-scale rebars for buildings were developed with the same design concept. Quasi-static lateral cyclic loading tests were conducted with reinforced and precast concrete members to verify the seismic performance. Also, shaking table tests with three types of seismic wave excitation, 1) random wave with white noise, 2) the 2016 Gyeongju earthquake, and 3) the 1999 Chi-Chi earthquake, were conducted to confirm the dynamic performance. All tests were performed with real-scale concrete specimens. Sensors measured the lateral load, acceleration, displacement, crack pattern, and secant system stiffness, and energy dissipation was determined by lateral load-displacement relation. As a result, the precast specimen provided the emulative performance with RC. In the shaking table tests, PC frames' maximum acceleration and displacement response were amplified 1.57 - 2.85 and 2.20 - 2.92 times compared to the ground motions. The precast specimens utilizing clamped mechanical splice showed ductile behavior with energy dissipation capacity against strong motion earthquakes.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.684-698
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• 2024

We investigated Cissus quadrangularis L. powder (C) use as a natural additive to Tteokgalbi, a traditional Korean meat-based dish. Five distinct Tteokgalbi samples were treated: one without any additives (negative control, NC), one with 1.00% C (C1), 2.00% C (C2), 4.00% C (C3), and 0.10% ascorbic acid (positive control, PC). C addition resulted in changes in composition, quality, and sensory attributes. Moisture content decreased with higher C levels; crude protein varied among the groups, with C1 having the highest crude protein levels and C3 the lowest. Crude fat decreased with increasing C concentration, whereas the carbohydrate content increased. The water-holding capacity notably decreased in the C3 group, resulting in increased cooking loss with higher C concentrations. C treatment altered color and texture, reducing CIE L^* and increasing CIE a^* before cooking and increasing CIE L^* and CIE a^* after cooking. CIE b^* decreased before cooking but increased thereafter. C-treated Tteokgalbi was less cohesive, chewy, and brittle compared to the NC. The C treatment increased the total phenolic and flavonoid contents and enhanced radical scavenging capacities. It also affects storage characteristics, lowers pH, and increases 2-thiobarbituric acid reactive substances values. The microbial counts were lower in C2 and C3 after 11 days. These findings suggest the potential use of C as a natural meat additive.

• Journal of Embryo Transfer
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• v.17 no.1
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• pp.45-53
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• 2002

The main goal of this study was to produce transgenic porcine embryos by direct injection of sperm-mediated exogenous DNA. Spermatozoa (6$\times$10$^{6}$ sperms of final concentration) were mixed with pcDNA LAC Z (20 ng/$\mu$l) and subjected into electroporation (300~750 volts, 25 $\mu$F, 0.4 cm electrode). After sperm injection, the oocytes were activated electrically (1.7 KV/cm, 30$\mu$sec, single pulse) in 0.3 M mannitol solution or not. The sperm injected eggs were cultured in NCSU 23 medium (0.4% BSA) at 39$^{\circ}C$, 5% $CO_2$ in air fur 144 h. The rates of cleavage and development into blastocyst stage in activation group were significantly higher than those of non-activation group (79.6% and 24.1% vs. 46.3% and 14.4%, respectively, p<0.05). Control oocytes and shame injection were developed to blastocysts low (2.5%). Sixty five (27.1%) out of 240 embryos observed in activation and non-activation groups were showed positive by X-gal staining. However, all embryos in both groups were expressed partial or mosaic pattern. These results suggested that electrical stimulation far oocytes activation after sperm injection enhances the incidence of both fertilization and development fellowing sperm injection in the pig. Our study also suggested that sperm-mediated transfer of exogenous DNA by ICSI would be used as a valuable tool for the production of transgenic porcine embryos.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.265-274
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• 1998

In order to attain a sustained release at targeted organs in a prolonged time which can reduce the side effects and maximize the therapeutic effect, aclarubicin (ACL) was entrap ped into liposomes of different lipid compositions using Microfluidizer, and dry liposomes were prepared by lyophilization. The dry aclarubicin-entrapped liposomes were evaluated in terms of mean particle size and size distribution, entrapment efficiency and in vitro drug release profile. The Entrapment efficiency of liposome, when the concentration of aclarubicin and lipid were 0.5 to 1.0mg/ml and $200{\mu}mol$/ml, respectively, was over 80% using Microfluidizer, in contrast to 70% of entrapment efficiency using hand-shaking method. Mean particle size and size distribution of aclarubicin-entrapped liposomes of various lipid compositions did not change considerably by the freeze drying. The range of particle size was between 80 and 200nm. Among aclarubicin-entrapped liposomes, ACL-liposome of PC/DPPC/CH0L/TA displayed the most significant sustained release. The addition of DPPC appeared to be favorable for the control of release. In general, aclarubicin entrapped in liposomes was less stable than free aclarubicin either in pH 7.4 phosphate buffer or in human plasma. Formulation I($t_{1/2}$, 20.3 hr) devoid of lipid additive was the most unstable in the phosphate-buffer solution while formulation II($t_{1/2}$, 40.7 hr) with cardiolipin was the most stable. Half lives of aclarubicin-entrapped liposomes in human plasma were 43.2, 50.7, 35.9 and 35.3 hr for formulation I. II, III and IV, respectively, in contrast to 57.8 hr for free aclarubicin.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.679-687
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• 2018

Korean red pine (Pinus densiflora) is one of the major Pinus species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects. In this study, we investigated if Korean red pine bark extract (KRPBE) could protect neuronal PC-12 cells from oxidative stress and inhibit cholinesterase activity. Analysis of reversed-phase high-performance liquid chromatography results revealed four phenolics in KRPBE: vanillin, protocatechuic acid, catechin, and taxifolin. The total phenolic and flavonoid contents of KRPBE were 397.9 mg gallic acid equivalents/g dry weight (DW) and 248.7 mg catechin equivalents/g DW, respectively. The antioxidant capacities of KRPBE measured using ABTS, DPPH, and ORAC assays were 697.3, 521.8, and 2,627.7 mg vitamin C equivalents/g DW, respectively. KRPBE and its identified phenolics protected against $H_2O_2$-induced oxidative cell death in a dose-dependent manner. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission in synaptic clefts, were inhibited by treatment with KRPBE and its identified phenolics. Taken together, these results suggest that KRPBE and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.

• Korean Journal of Adult Nursing
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• v.12 no.1
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• pp.134-146
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• 2000

This study was conducted to investigate the relationship between self-esteem, health promoting behavior and the quality of life of the patients undergoing hemodialysis. The subjects were 86 patients undergoing hemodialysis in H hospital. The data were collected using a questionnaire. Data collection was done from January 11th to June 16th, 1999. The analysis of data was done by use of descriptive statistics, t-test, ANOVA, Pearson Correlation Coefficient and Multiple regression using the SPSS/PC+ program. The results are as follows: 1. The mean of the level of self-esteem was 25.02, the level of health promoting behavior, 120.04 and the level of QOL, 128.09. 2. Test for hypothesis: Hypothesis 1. "The higher the level of self-esteem of the patients undergoing hemodialysis, the higher the level of quality of life will be." was supported(r=.296, p<.01). Hypothesis 2. "The higher the level of health promoting behavior, the higher the level of quality of life will be." was supported (r=.628, p<.001). 3. Health promoting behavior explained 39.5percent of QOL($R^2$=.395, F=27.040, p<.001). 4. Monthly income(F=3.85, p<.01) and marital status(F=4.64, p<.05) were significantly related to the quality of life In conclusion, this study showed that self-esteem and health promoting behavior may be important factors that can improve the quality of life of the patients undergoing hemodiaysis. This study identified that nursing plans should include these factors to help physical, psychological and social adaptation of the patients undergoing hemodialysis.