• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.4
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• pp.225-235
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• 2010

This study was aimed to assess the status of working environment, health care management status and cause of exposure in manufactories using dimethylformamide (DMF). For the purpose, airborne concentration of DMF in the workplaces and N-methylformamide (NMF) in worker's urine were measured with job type and process. In addition, management of local exhaust ventilation system (LEV) and personal protective equipment (PPE) was evaluated at 35 work places (107 workers) located in Busan and Gimhae area. Mean DMF concentrations in work places by job type and process were of high level measured in printing and record media reproduction (5.23 ppm) and flaking process (2.48 ppm). Workers in adhesive job were measured a large amount of urine NMF (21.59 mg/${\ell}$). 98.1% of DMF handling workers were provided respirators, but 67.3% of those workers used them. The main reasons for not using respirators were inconvenience and difficulty of breathing. Airborne concentrations of DMF were higher in the workplaces in which LEVs were working abnormally, but there was not statistically significant. In addition, the urine NMF levels were correlated with management of LEV within the workers who did not use the respirators (p<0.048). These results implied that LEV should be installed and maintained properly to protect the workers from the exposure to DMF. Management of PPE should be also necessary to protect the workers from chemical hazards.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.275-285
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• 2005

Ipriflavone (isoprofoxyisoflavone), a synthetic derivative from soy isoflavone diazein, has been shown to inhibit bone resorption and perhaps stimulate bone formation This study was performed to examine the effects of ipriflavone on the proliferation and bone remodeling in rat calvarial cells in vitro The rat calvarial cells were isolated from fetus aged 20 to 21 days and cultured In BGJb media The graded concentration of ipriflavone $(10^{-9}\;10^{-5}M)$ was administered into cultured cells. When the cell proliferation was estimated through the measurement of MTT assay, there was no increase in cellular proliferation of the rat calvarial cell at any ipriflavone concentration. The cellular activity was evaluated through the formation of mineralized nodules stained by alizarin red. The formation of mineralized nodules significantly increased at concentrations of $10^{-8}M,\;10^{-7}M\;and\;10^{-6}M$ ipriflavone. Reverse transcription-polymerase chain reaction analyses (RT-PCR) were done at 7 and 14 days after culture to detect the expression of Bone Sialoprotein (BSP), Type I Collagen (COL I) and Osteocalcin(OCN) As a result, the expressions of BSP and COL I increased on the 7th day of culture and the expression of OCN increased on the 14th day of culture. These results indicate that ipriflavone facilitates the bone remodeling process bvy promoting rat calvarial cell differentiation aid stimulating mineralization through increased expression of extracellular matrix genes. such as BSP. COL I and OCN.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.245-252
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• 2006

A bacterial strain, identified as Staphylococcus aureus JJ-11, producing collagenase was isolated out of 40 persons having skin troubles. S. aureus JJ-11 produced collagenase optimally in the media containing 1.5%(w/v) gelatin, 1%(w/v) yeast extract, 0.4%(w/v) $K_2HPO_4$, 0.005%(w/v) $NiSO_4{\cdot}6H_2O$ at $37^{\circ}C$ for 18 hrs. The collagenase produced by Staphylococcus aureus JJ-11 was purified at 6.66-folds purity through application of chromatography with Amberlite IRA-900 and Sephacryl S-300 HR columns. The molecular weight of the partially purified enzyme was estimated to be 62 kDa by SDS-PAGE. The protein exhibited optimum enzymatic activity at pH 7.0, and showed a stable activity at pH 4-8. The optimum temperature for collagenase was at $37^{\circ}C$, and activity was maintained upto $40^{\circ}C$. The enzyme activity was slightly elevated in the presence of divalents such as, $Fe^{2+},\;Co^{2+}\;and\;Ba^{2+}$ However, the activity was inhibited in the presence of $Sr^{2+}\;or\;Hg^{2+}$. The inhibition of activity by O-phenanthroline and EDTA suggested that the enzyme may contain metal which is required for activity. The enzyme showed the highest activity when insoluble collagen (type I) was, used as a substrate.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.386-390
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• 2005

This study was conducted to develop the biofilter fur reducing ammonia $(NH_3)$ and hydrogen sulfide $(H_2S)$ gas emission from a pig house. A biofilter was designed and constructed by a type of squeeze air into the column type of air flow upward. Its column size was ${\Phi}260{\times}360mm$. It was used pressure drop gauge, turbo blower, air temperature, velocity sensor and control program that was programed by LabWindows CVI 5.5. Mixing materials were consisted with composted pine tree bark and perlite with 7:3 ratio (volume). The biofilter media inoculated with ammonia (Rhodococcus equi A3) and hydrogen sulfide (Alcaligenes sp. S5-5.2) oxidizing microorganisms was installed in a commercial pig house to analyzed the effectiveness of biogas removal for 10 days. Removal rates of ammonia and hydrogen sulfide gases were 90.8% and 81.5%, respectively. This result suggests that the pine compost-perlite mixture biofilter is effective and economic for reducing ammonia ana hydrogen sulfide gases.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.79-92
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• 2011

In this study, wave pressure of short-period gravity waves and tsunami acting on the upright section of the horizontal-slit type caisson placed on the impermeable or permeable seabed, which is a well-known permeable breakwater with a good wave controlling ability, are investigated via numerical simulations. Further, the permeable seabed was modeled as the porous media with porosity of 0.4. Using the numerical results, the effects of the seabed conditions on the wave pressure on the front wall and inside wall of the chamber have been studied. In the numerical simulations, short-period gravity waves and tsunami(solitary wave or bore) with the same amplitude to the gravity wave are considered. A numerical wave tank is used, which is able to consider a gas-liquid two-phase flow in the same calculation zone. Numerical results show that the wave pressure of the tsunami was 3~5 times higher than the short-period gravity waves acting on the front wall and it was 2~4 times higher than the short-period gravity waves acting on the inner wall.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.221-225
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• 2011

This study was undertaken to evaluate the relationship between in vitro maturation and plasminogen activators (PAs) activity on porcine cumulus-oocytes complexes (COCs) exposed to oxidative stress. When COCs were cultured in maturation medium with hydrogen peroxide ($H_2O_2$), the proportion of the germinal vesicle breakdown (GVBD) and oocytes maturation were decrease with addition of $H_2O_2$, and were significantly (p<0.05) lower in medium with 0.1 mM $H_2O_2$ than control group. Also, the rate of degenerated oocytes was increased in as $H_2O_2$ concentration in eased. When COCs were cultured for 48 h, three plasminogen-dependent lytic bands were observed: tissue-type PA (tPA); urokinase-type PA (uPA); and tPA-PA inhibitor (tPA-PAI). PA activity was quantified using SDS-PAGE and zymography. When $H_2O_2$ concentration was increased, tPA and tPA-PAI activities also increased in porcine oocytes cultured for 48 h, but not uPA. In other experiment, embryos were divided into three groups and cultured in (1) control medium, (2) control medium with 1.0 mM $H_2O_2$ and (3) control medium with 1.0 mM $H_2O_2$ along with catalase in concentrations of 0.01, 0.1, and 1.0 mg/ml, respectively. $H_2O_2$ decreased the rate of GVBD and maturation in porcine COCs but catalase revealed protective activity, against oxidative stress caused by $H_2O_2$. In this experiment, tPA and tPA-PAI activities were higher in media with 1.0 mM $H_2O_2$ alone. Increasing concentration of catalase decreased tPA and tPA-PAI activities in porcine oocytes. These results indicate that the exposure of porcine follicular oocytes to ROS inhibits oocytes maturation to metaphase-II stage and increase the oocytes degeneration. Also, we speculated that increased ROS level may trigger tPA and tPA-PAI activities in porcine oocytes matured in vitro.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1319-1326
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• 2014

Rapamycin, produced by the soil bacterium Streptomyces hygroscopicus, has the ability to suppress the immune system and is used as an antifungal, anti-inflammatory, antitumor, and immunosuppressive agent. In an attempt to increase the productivity of rapamycin, mutagenesis of wild-type Streptomyces hygroscopicus was performed using ultraviolet radiation, and the medium composition was optimized using glycerol (which is one of the cheapest starting substrates) by applying Plackett-Burman design and response surface methodology. Plackett-Burman design was used to analyze 14 medium constituents: M100 (maltodextrin), glycerol, soybean meal, soytone, yeast extract, $(NH_4)_2SO_4$, $\small{L}$-lysine, $KH_2PO_4$, $K_2HPO_4$, NaCl, $FeSO_4{cdot}7H_2O$, $CaCO_3$, 2-(N-morpholino) ethanesulfonic acid, and the initial pH level. Glycerol, soytone, yeast extract, and $CaCO_3$ were analyzed to evaluate their effect on rapamycin production. The individual and interaction effects of the four selected variables were determined by Box-Behnken design, suggesting $CaCO_3$, soytone, and yeast extract have negative effects, but glycerol was a positive factor to determine rapamycin productivity. Medium optimization using statistical design resulted in a 45% ($220.7{\pm}5.7mg/l$) increase in rapamycin production for the Streptomyces hygroscopicus mutant, compared with the unoptimized production medium ($151.9{\pm}22.6mg/l$), and nearly 588% compared with wild-type Streptomyces hygroscopicus ($37.5{\pm}2.8mg/l$). The change in pH showed that $CaCO_3$ is a critical and negative factor for rapamycin production.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.1 s.8
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• pp.149-155
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• 2003

The reason of source for a tragic death by the occurrence of an event is $\ulcorner$unobservant of safety rule,$\lrcorner$ $\ulcorner$negligence of staff,$\lrcorner$ $\ulcorner$deficiency of responsibility$\lrcorner$ and $\ulcorner$deficiency of safety value$\lrcorner$ and for certain reason that is insufficiency of space for safety education also think little of a people, unobservant of safety rule, selfishness and so on. It makes new and specific plan that is simulation room before I compare the inside and outside of the country for a nation the reform of consciousness. Next, go ahead with a plan for about safety-simulation room. The Government can support to plan if it make a proposal to center of Government. It should be make a people of safety system, and it build the safety-simulation room $1{\sim}2$ in the city or county. And, the city cannot build the big safety-simulation room the reason are size of building and money. Accordingly, it will be make a system and installation for different type of safety-simulation room for about calamity, disaster and different type of accident in Korea. It must be build the building of space that should be make a space of knowledge and information by many books and media, develop of education program from life-safety.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.398-406
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• 2015

Culture-dependent ARDRA and culture-independent DGGE were employed to investigate the bacterial community associated with the marine sponge Halichondria panicea collected from Jeju Island. A total of 120 bacterial strains associated with the sponge were cultivated using modified Zobell and Marine agar media. PCR amplicons of the 16S rRNA gene from the bacterial strains were digested with the restriction enzymes HaeIII and MspI, and then assigned into different groups according to their restriction patterns. The 16S rRNA gene sequences derived from ARDRA patterns showed more than 96% similarities compared with known bacterial species, and the isolates belonged to four classes, Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and Firmicutes, of which Alphaproteobacteria was dominant. DGGE fingerprinting of 16S rRNA genes amplified from the sponge-derived total gDNA showed 14 DGGE bands, and their sequences showed 100% similarities compared with the sequences available in GenBank. The sequences derived from DGGE bands revealed high similarity with the uncultured bacterial clones. DGGE revealed that bacterial community consisted of seven classes, including Alphaproteobacteria, Gammaproteobacteria, Acidobacteria, Actinobacteira, Bacteroidetes, Cyanobacteria, and Chloroflexi. According to both the ARDRA and DGGE methods, three classes, Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes, were commonly found in H. panicea. However, overall bacterial community in the sponge differed depending on the analysis methods. Sponge showed more various bacterial community structures in culture independent method than in culture-dependent method.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.137-144
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• 2020

Based on the basic concepts and roles of the Science Museum, the research and development of the "Sound Light" interaction exhibition contents and experience exhibition space aimed at providing the exhibition, education and experience of scientific principle directly related to daily life will be implemented in the "Sound Light" exhibition space of the Gwangju National Science Museum. The scope of the research is to define the conditions and elements of the museum's hands-on exhibition by examining the case and status of the existing science museum's experience-type content prior research, and research and development of experience-type exhibition scenarios and contents for children based on them. The results of this research and development content are firstly developed with the theme of light and sound as interactive hologram experience content. Second, by multi-faceted media facade through projection mapping by multiple projectors, visual wide and spectacular screen composition and animation are realized. Third, visitors-oriented exhibitions and experiences that can interact with visitors by moving various colors and sounds together. Finally, interactive content is provided through hologram interfaces through hologram screens to encourage active participation of many visitors in viewing rather than simply delivering exhibition information and to promote revisiting the exhibition. Through a series of studies, it was possible to research and develop contents and experience exhibition spaces with theme park characteristics, which are the trend of science museums.