• Journal of Sensor Science and Technology
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• v.24 no.5
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• pp.291-298
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• 2015

There are many landslides occurred by typhoons and intense rainfall during the summer seasons in Korea. To predict a landslide triggering it is important to understand mechanisms and potential areas of landslides by the geological approaches. However, recent climate changes make difficult to predict landslide based on only conventional prediction methods. Therefore, the importance of a real-time monitoring of landslide using various sensors is emphasized in recent. Many researchers have studied monitoring techniques of landslides and suggested several monitoring systems which can be applicable to the natural terrain. Most sensors of landslide monitoring measure slope displacement, hydrogeologic properties of soils and rocks, changes of stress in soil and rock fractures, and rainfall amount and intensity. The measured values of each sensor are transmitted to a monitoring server in real-time. The ultimate goal of landslide monitoring is to warn landslide occurrence in advance and to reduce damages induced by landslides. This study introduces the current situation of landslide monitoring techniques in each country.

• Science of Emotion and Sensibility
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• v.12 no.2
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• pp.169-180
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• 2009

The present study have investigated the effect of the characteristics of stereoscopic images and viewing environment on visual fatigue. We manipulated the speed of stereo images with motion-in-depth and viewing distance, which were used as representative variables of the characteristics of stereo image and viewing environment, respectively. Visual fatigue was evaluated with use of a subjective questionnaire which is consisting of 5 different and independent factors: "Eye pain", "Visual stress," "Nauseousness", "Body stiffness", and "Blurriness". In general, when viewing time increased from 10 minutes to 20 and 40 minutes, observers felt severe visual fatigue. Among other factors, only the factor score of "Nauseousness" was significantly increased as the speed of object moving in depth became faster. When viewing distance was increased, the score of "Blurriness" was decreased. These results suggest that different kind of the visual fatigue might be induced depending on characteristics of the stereo images and viewing environment.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.198-206
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• 2010

The aim of this work was to investigate the synergically bactericidal effects and cellular responses of tea polyphenols (TPP) and imipenem on imipenem-resistant Pseudomonas aeruginosa. Imipenem-resistant Ps. aeruginosa was isolated from patient in hospital. The bactericidal effects of TPP and imipenem were evaluated on the basis of its minimum inhibitory concentrations (MIC). The combined use of TPP and imipenem resulted in 16-fold and 8-fold reductions in the MICs of imipenem for the imipenem-susceptible and imipenem-resistant Ps. aeruginosa, respectively. The bactericidal effects of the imipenem and TPP against the Ps. aeruginosa was evaluated using the time-kill assay. The synergetic effects of the combinations of TPP and imipenem against Ps. aeruginosa were confirmed. Western blot using anti-DnaK and anti-GroEL monoclonal antibodies was performed to investigate the expression of stress shock proteins (SSPs) in imipenem-susceptible and imipenem-resistant strains exposed to TPP. The amount of SSPs were induced as the exposure time increased and decreased. The molecular weights of DnaK and GroEL were 70 kDa and 60 kDa, respectively. SDS-PAGE with silver staining revealed that the amount of lipopolysaccharides (LPS) increased or decreased in the strain treated to different concentrations and exposing periods of TPP. Scanning electron microscopic analysis demonstrated the presence of umblicated and wrinkled surfaces for cells treated with TPP or imipenem.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.63-71
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• 2012

As nanotechnology is a key industry, there is growing concern relating to the potential risk of nanoparticles. They are known to be released into the environment via various exposure routes. When nanoparticles are present in water environments, they are supposed to be illuminated by ultraviolet light, and the ecotoxicity of photoactive nanoparticles may be changed. In this study, a review of the ecotoxicity of photoactive nanoparticles, including the mechanisms of phototoxicity, are presented. In order to address this issue, studies on the ecotoxicity to soil and water organisms exposed to photoactive nanoparticles were investigated. The photoactive nanoparticles chosen for this study were zinc oxide, titanium dioxide and fullerene. Microorganisms, nematode, earthworm, algae and fish, etc., were chosen to assess the toxicity of nanoparticles using diverse methods. However, studies on the phototoxicity potentially induced by nanoparticles on UV illumination have been reviewed in only 8 studies. From a few studies, photoactive nanoparticles have shown high dissolution rates under UV conditions, with the released ions observed to profoundly influence test organisms. In addition, NPs exposed to UV produced reactive oxygen species (ROS). These ROS can induce oxidative stress in exposed organisms. Evidence of phototoxicity by nanoparticles were found based on previous studies.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.109-118
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• 2007

The excavation damaged zone (EDZ) is an area around an excavation where in situ rock mass properties, stress condition. displacement. groundwater flow conditions have been altered due to the excavation. Various studies have been carried out on EDZ, but most studies have been focused on the mechanical bahavior of EDZ by in situ experiment. Even though the EDZ could potentially form a high permeable pathway of groundwater flow, only a few studies were performed on the analysis of groundwater flow in EDZ. In this study, the' hydraulic EDZ' was defined as the rock Lone adjacent to the excavation where the hydraulic aperture has been changed due to the excavation. And hydraulic EDZ (hydraulic aperture changed zone) estimated by two-dimensional DEM program was considered in three-dimensional DFN model. From this approach the groundwater flow characteristics corresponding to hydraulic aperture change were examined. Together. a parametric study was performed to examine the boundary conditions that frequently used in DFN analysis such as constant head or constant flux condition. According to the numerical analysis, hydraulic aperture change induced by the hydraulic-mechanical interaction becomes one of the most important factors Influencing the hydraulic behavior of jointed rock masses. And also from this study, we suggest the proper boundary condition in three-dimensional DFN model.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.245-253
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• 2009

For the growth optimization of InAs/GaSb (8/8-ML) strained-layer superlattice (SLS), the structure has been grown under various conditions and modes and characterized by the high-resolution x-ray diffraction (XRD) analysis. In this study, the strain modulation is induced by changing parameters and modes, such as the growth temperature, the ratio of V/III beam-equivalent-pressure (BEP), and the growth interruption (GI), and the strain variation is analyzed by measuring the angle separation of 0th-order satellite peak in XRD patterns. The XRD results reveal that the growth temperature and the V/III(Sb/Ga) ratio are major parameters to change the crystallineity and the strain modulation in SLS structures, respectively. We have observed that the SLS samples with compressive strain prepared in this study are show a transition to tensile strain with decreasing V/III(Sb/Ga) ratio, and the GI process is a sensitive factor giving rise to strain modulation. These results obtained in this study suggest that optimized growth temperature and V/III(Sb/Ga) ratio are $350^{\circ}C$ and 20, respectively, and the appropriate GI time is approximately 3 seconds just before InAs growth that the crystallineity is maximized and the strain relaxation is minimized.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.298-306
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• 2004

Purpose: The purpose of this study was to identify Radiosensitivity of proteins in tissues with different radiosensitivity. Materials and Methods: C3H/HeJ mice were exposed to 10 Gy. The mice were sacrifiud 8 hrs after radiation. Their spleen and liver tissues were collected and analyzed histologicaly for apoptosis. The expressions of radiosusceptibillty protein were analyzed by 2-dimensional electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Resilts: The Peak of apoptosis levels were $35.3{\pm}1.7{\%}$ in spleen and $0.6{\pm}0.2{\%}$ in liver at 8 hrs after radiation. Liver, radioresistant tissues, showed that the levels of ROS metabolism related to proteins such as cytochromm c, glutathione S transferase, NADH dehydrogenase, riken cDNA and peroxiredoxin Vl increased after radiation. The expression of cytochrome c increased significantly in spleen and liver tissues after radiation. In spleen, radiosensitivity tissue, the identified proteins showed a significantly quantitative alteration following radiation. It was categorized as signal transduction, apoptosis, cytokine, Ca signal related protein, stress-related protein, cytoskeletal regulation, ROS metabolism, and others. Conclusion: Differences of radiation-induced apoptosis by tissues specifted were coupled with the induction of related radiosensitivity and radioresistant proteins. The result suggests that apoptosis relate protein and redox proteins play important roles in this radiosusceptibility.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.502-506
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• 2014

Recently nano particles have proven for wide array of bioactive properties. In the present study, antibacterial properties of chitosan silver nano composites (CAgNCs) were investigated against fish pathogenic Edwardsiella tarda. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CAgNCs against E. tarda were $25{\mu}g/mL$ and $125{\mu}g/mL$, respectively. The field emission scanning electron microscope (FE-SEM) image of CAgNCs treated E. tarda showed the strongly damaged bacteria cells than non-treated bacteria. Furthermore, treatment of CAgNCs induced the level of intracellular reactive oxygen species (ROS) in E. tarda cells in concentration and time dependent manner suggesting that it may generate oxidative stress leading to bacterial cell death. In addition, MTT assay results showed that the lowest cell viability at $100{\mu}g/mL$ of CAgNCs treated E. tarda. Overall results of this study suggest that CAgNCs is a potential antibacterial agent to control pathogenic bacteria.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.200-207
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• 2018

At high salt concentration, glycine betaine is transported into Bacillus subtilis and growing rate of the cell is not suppressed. Also according to recent studies, cell growth is maintained normal growth rate at low temperature. Low temperature results in a stress response of Bacillus subtilis that is characterized by strong repression of major metabolic activities such as translation machinery and membrane transport. In this regards, genes showing cold sensitive phenotype are cold-induced DEAD box RNA helicases (ydbR, yqfR) and fatty acid desaturases (bkdR, des). Therefore to understand the effect of glycine betaine on cold growth of Bacillus subtilis, we investigated the effect of glycine betaine on growth rate of these deletion mutants showing cold sensitive phenotype. Glycine betaine strongly stimulated growth of wild type Bacillus subtilis JH642 and deletion mutants of ydbR and yqfR at $20^{\circ}C$ (190~686 min $T_d$ difference). On the other hands, glycine betaine does not show growth promoting effects on deletion mutants of bkdR, and des at cold conditions. Same cold protectant growth results were shown with the precursor choline instead of glycine betaine. We investigated the effects of detergents on the cell membrane in bkdR and des deficient strains associated with cell membrane. It was identified that bkdR deficient strain shows retarded growth with detergent such as Triton X-100 or N-lauryl sarcosine compared with wild type cell. Thus, it is possible that deletion mutation of bkdR modifies membrane structure and effects on transport of glycine betaine.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.936-941
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• 2006

To prevent human body injury from oxidative stress, antioxidants are very important and many research about antioxidants are generally being conducted. Hydrogen peroxide$(H_20_2)$ that is one of vitality oxygen species has been seen that cause various diseases, DNA damage and gene change. We have already known that the inhibition effect of Zizania latifolia Radix, Rhizoma on apoptosis induced by $H_2O_2$ in Neuro2A cell. And the purpose of this study was that we made a comparative study on the inhibition effect of apoptosis in Neuro2A cell on the region of Zizania latifolia(Radix, Rhizoma, Herba). Neuro2A cells were cultivated in RPMI(GibcoBRL) with 5% FBS and treated with $H_2O_2$ and Zizania latifolia(Radix, Rhizoma, Herba). Separately we measured the cell viability and analyzed DNA fragmentation. Activity of PARP, Cytochrome C, caspase-9, caspase-3, p53, p21, Bax and Bcl-2 in the cell was examined by using western blot. The results obtained were as Follows: The cell viability in all of Zizania latifolia (Radix, Rhizoma, Herba) treatment (60ug/m1<) decreased significantly compared with that of none treatment(p<0.001). Zizania latifolia Radix increased cell viability was most effective of three regions. But we had no significant difference among three regions. All of Zizania latifolia (Radix, Rhizoma, Herba) increased cell viability about twice as much as that being injury by $H_2O_2$,(Zizania Latifolia (Radix, nhizoma, Herba) 20ug/m1, $H_2O_2$ 200uM, p<0.001). DNA fragmentation developed by $H_2O_2$, but was not developed in all of Zizania latifolia (Radix, Rhizoma, Herba) treatment. PARP, Cytochrome C, caspase-9 and caspase-3 activated all by $H_2O_2$ but were not activated in all of Zizania latifolia (Radix, Rhizoma, Herba) treatment. P53, P2l and Bax activated by $H_2O_2$, and Bcl-2 got into inactivation. But the opposite results appeared in all of Zizania latifolia (Radix, Rhizoma, Herba) treatment. In conclusion, these results suggest that all of Zizania latifolia (Radix, Rhizoma, Herba) inhibit the development of DNA fragmentation and apoptosis by $H_2O_2$and the antioridant action of all of Zizania latifolia (Radix, Rhizoma, Herba) is effective.