• Journal of Korean Home Economics Education Association
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• v.22 no.4
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• pp.155-183
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• 2010

The purpose of this study is to obtain a suggestion for writing, revising, and reorganizing for the current Korean Home Economics Textbook. To achieve this goal, the housing unit in the Home Economics curriculums from eight kinds of Japanese textbooks were analyzed. The subject of analysis was Technology Home Economics textbook Home Economics Part 2 volumes used in middle school 2009 and Home Economics Synthesis 6 volumes in high school. Contents of main text, terminology, reading material, tables and activities were analyzed. The suggestions of this analysis are as followings. First according to the increase of the level of school, if the field of housing is organized to be intensified systematically with relation to education, the goal of the subject would be clearly realized to the students. Thus, the middle school curriculum and textbook of housing field should be constructed with the consideration of education level according to the grade and the level of school. The method of intensive education in single point of time would result in low efficiency so the current curriculum should be re-considered. Second, perspective of resident, local community, terrain environment, housing culture should be included in housing education so that the learner may value the relationship between him and the society, think of the earth environment, succeed and advance the traditional culture. Third, the curriculum of the housing field should be organized with the consideration of understanding the level of middle, high school students. Middle school, with their student's low understanding, should include more experiential activity such as experiment and practice in their curriculum. On the other hand, curriculum which can enable student to research problems on their own and to apply them in their real life is required in high school course.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.33-40
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• 2004

Benzoyl peroxide is a High Production Volume Chemical, which is produced about 1,371 tons/year in Korea as of 2001 survey. The substance is mainly used as initiators in polymerization, catalysts in the plastics industry, bleaching agents for flour and medication for acne vulgaris. In this study, Quantitative Structure-Activity Relationships (QSAR) are used for getting adequate information on the physical -chemical properties of this chemical. And hydrolysis in water, acute toxicity to aquatic and terrestrial organisms for benzoyl peroxide were studied. The physical -chemical properties of benzoyl peroxide were estimated as followed; vapor pressure=0.00929 Pa, Log $K_{ow}$ = 3.43, Henry's Law constant=3.54${\times}$10$^{-6}$ atm-㎥/mole at $25^{\circ}C$, the half-life of photodegradation=3 days and bioconcentration factor (BCF)=92. Hydrolysis half-life of benzoyl peroxide in water was 5.2 hr at pH 7 at $25^{\circ}C$ and according to the structure of this substance hydrolysis product was expected to benzoic acid. Benzoyl peroxide has toxic effects on the aquatic organisms. 72 hr-Er $C_{50}$ (growth rate) for algae was 0.44 mg/1.,48 hr-E $C_{50}$ for daphnia was 0.07mg/L and the 96hr-L $C_{50}$ of acute toxicity to fish was 0.24mg/L. Acute toxicity to terrestrial organisms (earth worm) of benzoyl peroxide was low (14 day-L $C_{50}$ = > 1,000 mg/kg). Although benzoyl peroxide is high toxic to aquatic organisms, the substance if not bioaccumulated because of the rapid removal by hydrolysis (half-life=5.2 hr at pH 7 at $25^{\circ}C$) and biodegradation (83% by BOD after 21 days). The toxicity observed is assumed to be due to benzoyl peroxide rather than benzoic acid, which shows much lower toxicity to aquatic organisms. One can assume that effects occur before hydrolysis takes place. From the acute toxicity value of algae, daphnia and fish, an assessment factor of 100 was used to determine the predicted no effect concentration (PNEC). The PNEC was calculated to be 0.7$\mu\textrm{g}$/L based on the 48 hr-E $C_{50}$ daphnia (0.07 mg/L). The substance shows high acute toxicity to aquatic organisms and some information indicates wide-dispersive ore of this substance. So this substance is, a candidate for further work, even if it hydrolysis rapidly and has a low bioaccumulation potential. This could lead to local concern for the aquatic environment and therefore environmental exposure assessment is recommended.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.272-279
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• 2019

The study was conducted to evaluate the seminal attributes and cryobanking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 10⁶ cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN₂) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 10⁶ cells/mL vs. 1060.0 ± 44.3 × 10⁶ cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.

• Natural Product Sciences
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• v.11 no.2
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• pp.103-108
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• 2005

Bioflavone quercetin is thought to have an important role to inhibit bone loss by affecting osteoclastogenesis and regulating a number of systemic and local factors such as hormones and cytokines. In this study, we examined how quercetin acts on cytokine production and mineralization of osteoblast in the presence of tumor necrosis factor-alpha $(TNF-{\alpha})$ which has been known to play a pivotal role in bone metabolic diseases. Quercetin inhibited $TNF-{\alpha}-induced$ secretion of $IFN-{\gamma}$ and IL-6 in differentiated MC3T3-E1 cells. As indicated by the markers that are characteristics of the osteoblast phenotype, such as alkaline phosphatase (ALP) activity and calcium deposition, quercetin treatment slightly prevented the $TNF-{\alpha}-induced$ dramatic inhibition of differentiation and mineralization of MC3T3-E1 cells. Further, quercetin inhibited the production of nitric oxide induced by $TNF-{\alpha}$ in the cells. Collectively, our findings indicate that quercetin inhibites $TNF-{\alpha}-induced$ secretion of inflammatory cytokines in differentiated MC3T3-E1 cells without any cytotoxic effects.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.422-431
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• 2017

The biogeochemical information of riverine organic matter gives a detailed and integrated recording of natural and anthropogenic activity within a watershed. To investigate the changes in quality and quantity of organic carbon transporting from mountain to ocean via river channels, we estimated the concentrations of dissolved (DOC) and particulate organic carbon (POC), and then traced the source origin of POC using stable carbon isotopes ratio before and after summer rainfalls in the Tamjin River and Ganjin Bay, Korea. Along the small watershed, a total of 13 sites including headwaters, dam reservoir, river and estuary were established for the study. We found some interesting findings in the aspect of distribution of DOC/POC concentration changing their origin sources dynamically flowing downstream. In particular, the river channel transport downstream mainly DOC to river mouth, although upper dam reservoir increased POC concentration by phytoplankton production in summer. Whereas, in the river mouth and estuary, POC was dominated not only by local supply from nearby reed saltmarsh, but also by marine phytoplankton production, respectively. The findings can contribute to increasing the understanding of riverine organic carbon transport in upper large dam and lower open estuary system.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.194-199
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• 2005

In oder to select an antifungal substance-producing antagonistic bacterium against Fusarium oxysporum casuing fusarium wilt on tomato, strain BK4 was isolated from local soil of Gyeoungbuk and was identified as Bacillus thuringiensis by 16s rDNA analysis, biochemical test, and Mcirolog TM 3.0 System. The antibiotic of B. thuringiensis BK 4 was highly produced at $30^{\circ}C$ in nutrient broth (pH 9.0). The crude antibiotic was even stable at $121^{\circ}C$ and more stable at slight alkalic condition than acid condition. It was also remained $50{\%}$ activity at pH 3.0. B. thuringiensis BK4 showed the inhibition of spore germination and the biocontrol ability against F. oxysporum causing fusarium wilt of tomato in vivo test. According to these results, B. thuringiensis BK4 was enough to use with a microbial agent for biocontrol against fusarium wilt.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.61-69
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• 2014

As we are trying to in-situ treat (purify or immobilize) heavy metals or radionuclides in groundwater, one of the geochemical factors to be necessarily considered is the value of oxidation/reduction potential (ORP) of the groundwater. A biogeochemical impact on the characteristic ORP change of groundwater taken from the KAERI underground was observed as a function of time by adding electron-donor (lactate), electron-acceptor (sulfate), and indigenous bacteria in a laboratory condition. There was a slight increase of Eh (slow oxidation) of the pure groundwater with time under a $N_2$-filled glove-box. However, most of groundwaters that contained lactate, sulfate or bacteria showed Eh decrease (reduction) characteristics. In particular, when 'Baculatum', a local indigenous sulfate-reducing bacterium, was injected into the KAERI groundwater, it turned to become a highly-reduced one having a decreased Eh to around -500 mV. Although the sulfate-reducing bacterium thus has much greater ability to reduce groundwater than other metal-reducing bacteria, it surely necessitated some dissolved ferrous-sulfate and finally generated sulfide minerals (e.g., mackinawite), which made a prediction for subsequent reactions difficult. As a result, the ORP of groundwater was largely affected even by a slight injection of nutrient without bacteria, indicating that oxidation state, solubility and sorption characteristics of dissolved contaminants, which are affected by the ORP, could be changed and controlled through in-situ biostimulation method.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.33-41
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• 2016

In this study, it was to prepare a plan for improving the employment rate of college students after identifying employment preparation behavior by grade level. Based on data collected in this study, frequency analysis was analyzed and in order to find out the difference of employment preparation behavior between grade level, Cross-analysis was performed. The results, all items showed that significant differences by grade level in preparation for employment actions such as choice of a double major, workers' experience in college education services, language training experience in foreign countries, setting career in college education services, setting a goal for employment, seeking for employment in college education services, participation in employment activity for researching job, education/training-related job, having an official license. Implications for activation direction of employment preparation of college student by grade level is as follows. First, it is necessary for encouraging actively employment intention of the students. Second, there is a need for institutional support for certification and expanding language training opportunities. Third, in the case of a local university, it is necessary for enhancing competency for employment through the promotion of basic education for students.

• Clean Technology
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• v.21 no.4
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• pp.241-247
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• 2015

Oyster shells are a waste product from mariculture that creates a major disposal problem in coastal regions of southeast Korea. To make practical use of unused oyster shells, calcined oyster shell (COS) collected from a local company was allowed to adsorb AITC (allyl isothiocyanate), and then tested the powder's ability to inhibit the growth of some potential food borne disease-causing bacteria. COS powder showed bacteriostatic effect that inhibited cell growth of Escherichia coli, Staphylococcus aureus and Salmonella typhimurium from 3 to 5 log10 CFU/mL at concentrations around 1%. The MIC of pure AITC was found as 1 mg/mL, 0.8 mg/mL and 0.7 mg/mL for Escherichia coli, Staphylococcus aureus and Salmonella typhimurium, respectively. The calcined powder adsorbed about 225 mg of AITC per gram of shell, indicating porous material was created by calcination. FTIR data confirmed the adsorption of AITC by COS. Characterization of particle data showed very fine particle size and highly convoluted surface. AITC adsorbed calcined oyster shell (ACOS) completely inhibited bacterial cell at 1% concentration. ACOS showed better antibacterial effect than COS, indicating synergistic effect of AITC and calcined oyster shell powder on bacteria.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.551-560
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• 2015

Here we report the protective activity of cultured Acer tegmentosum cell extract against liver damage in rat intentionally instigated by D-galactosamine. Local fat degeneration and infiltration of inflammatory cells were significantly decreased in cultured A. tegmentosum cell extract administered rat. In addition, acutely increased AST, ALT, LDH, ALP activities and lipid peroxidation and lipid content by liver damage were recovered in experimental rat administrated with A. tegmentosum extract. These results showed that cultured A. tegmentosum cell extract has a role in blood enzyme activation and lipid content restoration within damaged rat liver tissues. Moreover expression rate of TNF-α which accelerates inflammation and induces tissue damage and necrosis was significantly decreased. Also activities of antioxidant enzymes were more effectively upregulated comparing to those of the control group induced hepatotoxicity. All data that cultured A. tegmentosum cell extract has a preventive role against liver damages such as inflammation, tissue necrosis in rats by improving activities of blood enzymes, antioxidant enzymes and modulating expression of inflammation factor, suggest that cultured Acer tegmentosum cell extract is an effective medicinal resource for restoration of hepatotoxicity.