• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.220-227
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• 2005

The estrogenic phenolic compounds, nonylphenol (NP), octylphenol(OP), bisphenol A (BPA) and nonylphenol mono- and diethoxylate ($NP_{1-2}EO$) were analyzed in 24 surface water samples from six rivers flowing into Masan Bay. All of the phenolic compounds were detected in all six rivers in high concentrations. The most abundant compound was $NP_{1-2}EO$ (86.0%), followed by NP ($10.1 \%$), BPA ($3.6\%$) and OP ($0.3\%$). The levels of phenolic compounds were 1.42-22.70 ${\mu}g$/L for $NP_{1-2}EO$, 0.15-1.68 ${\mu}g$/L for NP, 0.024-0.610 ${\mu}g$/L for BPA and 0.003-0.067 ${\mu}g$/L for OP. Especially, high concentrations were recorded in the rivers that pass through industrial complexes. The concentrations of phenolic compounds observed in these river waters were 1-2 orders of magnitude lower than the reported acute toxicity levels (hundreds of micrograms per liter). However, they were only slightly lower than the chronic toxicity levels. Most of the water samples also exceeded the Canadian nonylphenolic compounds water quality guideline, 1 ${\mu}g$/L, for the protection of aquatic life and the maximum permissible concentrations (MPC), 0.33 ${\mu}g$/L for NP and 0.12 ${\mu}g$/L for $NP_{1-2}EO$.

• The Korean Journal of Community Living Science
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• v.16 no.1
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• pp.105-111
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• 2005

This study was carried out to investigate the effect of Lentinus edodes which were harvested at different times of maturity on blood glucose and lipid levels in diabetic mice. The diabetic KK mice were fed diets supplemented with Lentinus edodes harvested early (LE) or late (LL) for eight weeks, and control (CO) mice were fed regular diet without Lentinus edodes. Diet intake, body weight, organ weight, blood glucose and serum lipid levels were measured. The mice which were fed diets supplemented with LE and LL showed significantly lower body weights compared to the CO group. There were no significant differences in the diet intake and the weights of different organs including liver, heart, kidneys, and epididymal fat pad among three different groups. Furthermore, the concentrations of serum triglycerides and total cholesterol were significantly lower in LE and LL groups compared to the CO group. These results clearly demonstrate that Lentinus edodes, regardless of their harvested period reduced body weight and serum lipid without affecting blood glucose level in diabetic mice.

• Korean Journal of Child Studies
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• v.23 no.1
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• pp.87-104
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• 2002

This study investigated developmental levels and explored play behaviors in 194 4- and 5-year-old children from low-income families attending 18 daycare centers in Seoul. The Developmental Test for Korean Kindergartners(Korea Institute Curriculum & Evaluation, 1996) was used to assess developmental levels in seven areas. Play behaviors were observed during free-play in their classrooms. Data were analyzed by two-way ANOVA and $x^2$. Results were that the children from low-income families showed highest scores in motor skill development and the lowest scores in mathematical and scientific development. The children engaged most frequently in group-functional play, followed by onlooker behaviors, group-dramatic, and group-constructive play. Onlooker behaviors were the most frequent activity of the 4-year-olds, and the block corner was the most frequently used area during free-play.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.230-235
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• 2012

This study was carried out to clarify effects of field location and sprayer on the level of pesticide residue in chilli peppers. As confirmed by statistical analysis, the residue levels in green pepper among three greenhouses did not show significant difference at the first day after spraying with the same engine sprayer and nozzle. But the residue levels in green peppers collected from the exposed outside of crop were 2 times higher than those from the hidden inside. The sampling site was one of variation elements of pesticide residue. The residue levels after application by knapsack engine powered sprayer were 1.7 times higher than those by manual compressed sprayer. As the spraying pressure of the engine power sprayer is 2 times higher than the commonly used pressure of the manual compressed sprayer, the pressure of the sprayer and nozzles were considered to affect on the residue levels in peppers.

• Journal of Korean Clinical Health Science
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• v.5 no.3
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• pp.953-962
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• 2017

Purpose. This study was conducted in order to identify levels of stress and self-esteem related to clinical practices of dental hygiene department students. Methods. Data was collected from a group of 249 students from October to November 2015, in the Yeong-nam region. Data analysis was performed using descriptive statistics frequency and t-test, logistic regressions by a SPSS WIN 18.0 program. Results. The results indicate that the characteristics of those who appeared to practice managing teaching was higher than that of the stress levels of clinical practice(p=.044). As well. personal relations(p=.013), degree of major satisfaction(p=.001), levels of satisfaction of practice(p=.019) resulted in higher levels of self esteem. The stress levels of clinical practice and high levels of satisfaction of practice were reduced and resulted in a dental hygienic negative correlation(p=.016). Self-esteem levels increased significantly according to personal relations(p=.001) and satisfaction of practice(p=.014). Conclusion. A strategy for development of a method to reduce the stress of clinical practice among individuals and an improvement of self-esteem programs which is necessary for dental hygiene students.

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.68-78
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• 2009

The purpose of this study was to investigate teaching anxiety and the professional development of beginning secondary science teachers. For this study, a survey was conducted among beginning science teachers (N=83) with under five years of experience, and in-depth interviews with these five teachers were carried out. The survey tackled beginning secondary science teachers' anxiety levels by asking about their difficulties in teaching science classes, and results showed that the teachers' levels of teaching anxiety marked high. Levels of teaching anxiety in physics among subjects and in chemistry among experiments marked highest. To overcome teaching anxiety, teachers searched for information on the Internet or received help from their colleagues and veteran teachers. They revealed that plans for professional development as science teachers included receiving in-service training and joining teacher communities. In addition, the best type of required training program for professional development appeared to be lectures about teaching know-how from veteran teachers.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.349-357
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• 2001

This study was conducted to examine the effect of caffeine and three dietary levels of fat, i.e., 0%, 5% and 20% on mammary gland development. Mice were assigned to three groups (dietary levels 0%, 5%, 20% fat), and treated caffeine of half within the each group. Caffeine-treated mice with 0% or 20% fat levels significantly increased 4$^{th}$ mammary gland development in comparison with that of no caffeine -treated mice (P＜0.05). Caffeine-treated mice significantly increased DNA contents of 4$^{th}$ mammary gland in comparison with that of no caffeine-treated mice (P＜0.05), and DNA contents of mammary gland increased as fat levels increased within caffeine-treated or no caffeine-treated group. nteraction effect was shown between caffeine and 20% fat diet, ［(20% fat+caffeine) - (20% fat + no caffeine) vs (0% fat + caffeine) - (0% fat + no caffeine)］(P＜0.01). Conclusively, caffeine significantly increased mouse mammary gland development possibly by inhibiting phosphodiesterase activity, and dietary fat supplements increased mammary gland development as the fat content of the diet increased from 0 to 20%. The stimulatory effect of caffeine in mammary development interacted with high level of fat diet.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.1003-1012
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• 2012

The gonadosomatic index (GSI), sex steroid hormones and gonadal development of roughscale sole Clidoderma asperrimum cultured in indoor tank were investigated to evaluate its sexual maturation and reproductive cycle. The highest GSI values of female and male were $6.91{\pm}4.03$ (May) and $0.16{\pm}0.08$ (August), respectively. The reproductive cycle would be classified into four successive developmental stages: growing stage (December to February), maturation stage (March to April), ripe and spawning stage (May to June), recovery and resting stage (July to November). The highest plasma testosterone (T) and estradiol-$17{\beta}$ ($E_2$) levels of female were $259.4{\pm}76.8$ and $633.3{\pm}182.5$ pg/mL, respectively in May. Also $17{\alpha}$, $20{\beta}$-dihydroxy-4-pregen-3-one ($17{\alpha}$, $20{\beta}$-OHP) levels of female peaked in April before spawning season ($244.2{\pm}42.5$ pg/mL). The highest plasma testosterone (T) and 11-ketotestosterone levels of male were $231.0{\pm}46.0$ and $273.9{\pm}54.5$ pg/mL, respectively in April. But there was no significant difference in $17{\alpha}$, $20{\beta}$-OHP.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.116-124
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• 2015

The objective of this study is to evaluate the effects of the replacement levels of grinded fly-ash on the repaired mortar based on a polymer. The main parameters are the curing temperature and replacement levels of grinded fly-ash. The curing temperature and the replacement levels of grinded fly-ash are varied at $40^{\circ}C$, $20^{\circ}C$ and $5^{\circ}C$, and between 0% and 35% of the total binder by weight, respectively. The flow in fresh mortar and compressive strengths according to ages, the relationship of stress-strain, elastic modulus and modulus rupture in hardened mortar, as well as scanning the electron microscopy and the X-ray diffraction of mortar, were measured, respectively. The test results showed that the flow, elastic modulus and modulus rupture are great in mortar specimens with 20~30% of the replacement levels of grinded fly-ash. In addition, compressive strengths according to ages were affected by the replacement levels of grinded fly-ash and the curing temperature indicated that the strength development ratio of mortar with 20% of the replacement levels of grinded fly-ash was greater than others. In the prediction of the compressive strength specified by the ACI 209 code, the strength development at an early and late age can be generalized by the functions of the replacement levels of grinded fly-ash and the curing temperature. In the analysis of scanning the electron microscopy and the X-ray diffraction, the number and intensity of peaks increased and the form of CSH gels on the surface of the particle of grinded fly-ash was observed.

• Development and Reproduction
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• v.23 no.1
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• pp.43-54
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• 2019

We examined the effects of endoplasmic reticulum (ER) stress inhibitor treatment during the micromanipulation of porcine somatic cell nuclear transfer (SCNT) on the in vitro development of SCNT embryos. ER stress inhibitors such as salubrinal (200 nM) and tauroursodeoxycholic acid (TUDCA; $100{\mu}M$) were added to the micromanipulation medium and holding medium. The expression of X-box binding protein 1 (Xbp1), ER-stress-associated genes, and apoptotic genes in SCNT embryos was confirmed at the one-cell and blastocyst stages. Levels of Xbp1 splicing and expression of ER-stress-associated genes in SCNT embryos at the one-cell stage decreased significantly with TUDCA treatment (p<0.05). The expression of ER-stress-associated genes also decreased slightly with the addition of both salubrinal and TUDCA (Sal+TUD). The expression levels of caspase-3 and Bcl2-associated X protein (Bax) mRNA were also significantly lower in the TUDCA and Sal+TUD treatments (p<0.05). At the blastocyst stage, there were no differences in levels of Xbp1 splicing, and transcription of ER-stress-associated genes and apoptosis genes between control and treatment groups. However, the blastocyst formation rate (20.2%) and mean blastocyst cell number ($63.0{\pm}7.2$) were significantly higher (p<0.05) for embryos in the TUDCA treatment compared with those for control (12.6% and $41.7{\pm}3.1$, respectively). These results indicate that the addition of ER-stress inhibitors, especially TUDCA, during micromanipulation can inhibit cellular damage and enhance in vitro development of SCNT embryos by reducing stress levels in the ER.