• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.45-55
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• 2007

Plant extract has attracted considerable interest in oral disease therapy. The present study was performed to observe the antibacterial effect on cariogenic Streptococcus mutans GS5 and Streptococcus sobrinus 6715, and periodontopathic Actinobacillus actinomycetemcomitans Y4 of phytoncide from Chamaecyparis obtusa Sieb. et Zucc employing the measurement of optical density, viable cell counts, and antibiotic sensitivity. The results were as follows: 1. Minimum inhibitory concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was observed to be 0.5%, 1%, and 0.2%, respectively. 2. Minimum bactericidal concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was determined to be 0.5%, 2%, and 0.2%, respectively. 3. The bacteria exposed to the phytoncide become more sensitive to antibiotics. The phytoncide enhanced significantly antibacterial activity of ampicillin against S. mutans and S. sobrinus. It also increased significantly the activity of penicillin and amoxicillin against S. sobrinus. In contrast, the phytoncide augmented the activity of amoxicillin and cefotaxime against A. actinomycetemcomitans but the increase was not statistically significant. The overall results indicate that phytoncide from Chamaecyparis obtusa Sieb. et Zucc used for this study has a strong antibacterial activity against cariogenic and periodontopathic bacteria and that it also has permeabilizing effect on certain antibiotics against these bacteria. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral infectious disease including dental caries and periodontal disease.

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.322-334
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• 2013

Objectives: This study describes the results of a mass screening and secondary questionnaire conducted among sampled residents around Camp Carroll. Methods: The subjects were sampled based on Waegwan groundwater ingestion history via a primary health questionnaire survey. However, the study population included voluntary participants and there were no grounds for disqualification. Among the 1,033 residents, excluding people living outside Waegwan, 844 subjects age 30 and over were analyzed. History of physician-diagnosed disease (including detailed history of cancer), eating habits, drinking and smoking histories were queried through questionnaires. Health screening consisted of a blood pressure check and blood test (complete blood cell, liver enzyme, lipid, blood sugar test, etc.). Results: The proportion of abnormal gamma-glutamyltransferase levels was higher in the groundwater ingesting female group than the non-ingesting female group. The odds ratios of the ingested '1 to 9 years' and '10 years and over' groups were 3.09 and 0.87, respectively. Proportions of hypertension in males, abnormal serum triglyceride levels in all and in females, and abnormal serum high density lipoprotein cholesterol levels in males were higher in the '10 to 29-year' resident group than in the '1 to 9 year' group. However, there were no significant trends according to length of residence. Conclusions: Physician-diagnosed prevalence and laboratory test results are not different by histories of Waegwan groundwater ingestion and by length of residence. Even if there are partially significant differences, they do not tend to follow increases of exposure amount and trends.

• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.278-283
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• 2004

The incidence of a pulmonary leiomyosarcoma as a primary lung tumor is quite rare. We report a case of primary leiomyosarcoma with a cardiac invasion in a 76 year old man. He was admitted due to left anterior chest wall pain for one month. Chest computed tomography showed a $9{\times}8{\times}10cm$ sized, large round mass in the left upper and lower lobes, and an amorphous low density lesion within the left atrium. Chest magnetic resonance imaging showed a large round mass in the left upper and lower lobes with growth into the left atrium. A diagnosis of leiomyosarcoma with prominent osteoclast-like giant cells was made based on the microscopic and immunohistochemical findings of a permanent specimen by explothoracotomy. The pathologic features of the tumor showed round mononuclear hyperchromatic cells and multinucleated giant cells that resembled osteoclasts. The immunohistochemical staining showed that the giant cells are positive for CD68 but negative for the muscle markers while the round cells were positive for the muscle marker. The patient refused further treatment and died after two months.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.79.2-79.2
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• 2017

To dynamically and chemically understand how filaments, dense cores, and stars form under different environments, we are conducting a systematic mapping survey of nearby molecular clouds using the TRAO 14 m telescope with high ($N_2H^+$ 1-0, $HCO^+$ 1-0, SO 32-21, and $NH_2D$ v=1-0) and low ($^{13}CO$ 1-0, $C^{18}O$ 1-0) density tracers. The goals of this survey are to obtain the velocity distribution of low dense filaments and their dense cores for the study of their origin of the formation, to understand whether the dense cores form from any radial accretion or inward motions toward dense cores from their surrounding filaments, and to study the chemical differentiation of the filaments and the dense cores. Until the 2017A season, the real OTF observation time is ~760 hours. We have almost completed mapping observation with four molecular lines ($^{13}CO$ 1-0, $C^{18}O$ 1-0, $N_2H^+$ 1-0, and $HCO^+$ 1-0) on the six regions of molecular clouds (L1251 of Cepheus, Perseus West, Polaris South, BISTRO region of Serpens, California, and Orion B). The cube data for $^3CO$ and $C^{18}O$ lines were obtained for a total of 6 targets, 57 tiles, 676 maps, and $7.1deg^2$. And $N_2H^+$ and $HCO^+$ data were added for $2.2deg^2$ of dense regions. All OTF data were regridded to a cell size of 44 by 44 arcseconds. The $^{13}CO$ and $C^{18}O$ data show the RMS noise level of about (0.1-0.2) K and $N_2H^+$ and $HCO^+$ data show about (0.07-0.2) K at the velocity resolution of 0.06 km/s. Additional observations will be made on some regions that have not reached the noise level for analysis. To identify filaments, we are using and testing programs (DisPerSE, Dendrogram, FIVE) and visual inspection for 3D image of cube data. A basic analysis of the physical and chemical properties of each filament is underway.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.931-935
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• 2012

In this study, we fabricate and investigate low-temperature solid oxide fuel cells with a ceramic substrate/porous metal/ceramic/porous metal structure. To realize low-temperature operation in solid oxide fuel cells, the membrane should be fabricated to have a thickness of the order of a few hundreds nanometers to minimize IR loss. Yttrium-doped barium zirconate (BYZ), a proton conductor, was used as the electrolyte. We deposited a 350-nm-thick Pt (anode) layer on a porous substrate by sputter deposition. We also deposited a 1-${\mu}m$-thick BYZ layer on the Pt anode using pulsed laser deposition (PLD). Finally, we deposited a 200-nm-thick Pt (cathode) layer on the BYZ electrolyte by sputter deposition. The open circuit voltage (OCV) is 0.806 V, and the maximum power density is 11.9 mW/$cm^2$ at $350^{\circ}C$. Even though a fully dense electrolyte is deposited via PLD, a cross-sectional transmission electron microscopy (TEM) image reveals many voids and defects.

• Journal of Life Science
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• v.30 no.8
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• pp.708-712
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• 2020

Vacuolar protein sorting (VPS) 26b is a newly discovered member of the retromer complex; it is encoded by a single-copy gene located on mouse chromosome 9, and the complex has been reported as being composed of proteins VPS26, VPS29, and VPS35. We have previously shown that mice lacking VPS26b exhibited no significant body size or health issues. Although retromer components are widely expressed in mouse tissue, their roles have not yet been completely elucidated. The current study investigates whether the VPS26b-associated retromer complex can be used as a neurodegeneration model. Previously, we observed a significant reduction in VPS35 and VPS29 in the brain cells of in VPS26b-deficient mice as well as an absence of the VPS26b-VPS29-VPS35 retromer complex despite the normal presence of VPS26a-VPS29-VPS35. Recent studies have suggested that low levels of VPS35 can lead to Alzheimer's disease-like phenotypes including cognitive memory deficits. In this study, we successfully demonstrate an association between the absence of the VPS26b-VPS29-VPS35 retromer complex, reduced cell density in the CA3 region of the hippocampus, and learning disability in VPS26b knock-out mice. The results also indicate that the VPS26b-associated retromer complex affects neurodegenerative disorders and learning processes.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.335-345
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• 2020

Tomato grey mould has been one of the destructive fungal diseases during tomato production. Ten mM of menadione sodium bisulfite (MSB) was applied to tomato plants for eco-friendly control of the grey mould. MSB-reduced tomato grey mould in the 3rd true leaves was prolonged at least 7 days prior to the fungal inoculation of two inoculum densities (2 × 10⁴ and 2 × 10⁵ conidia/ml) of Botrytis cinerea. Protection efficacy was significantly higher in the leaves inoculated with the lower disease pressure of conidial suspension compared to the higher one. MSB-pretreatment was not effective to arrest oxalic acid-triggered necrosis on tomato leaves. Plant cell death and hydrogen peroxide accumulation were restricted in necrotic lesions of the B. cinereainoculated leaves by the MSB-pretreatment. Decreased conidia number and germ-tube elongation of B. cinerea were found at 10 h, and mycelial growth was also impeded at 24 h on the MSB-pretreated leaves. MSB-mediated disease suppressions were found in cotyledons and different positions (1st to 5th) of true leaves inoculated with the lower conidial suspension, but only 1st to 3rd true leaves showed decreases in lesion sizes by the higher inoculum density. Increasing MSB-pretreatment times more efficiently decreased the lesion size by the higher disease pressure. MSB led to inducible expressions of defence-related genes SlPR1a, SlPR1b, SlPIN2, SlACO1, SlChi3, and SlChi9 in tomato leaves prior to B. cinerea infection. These results suggest that MSB pretreatment can be a promising alternative to chemical fungicides for environment-friendly management of tomato grey mould.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.829-835
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• 2010

This paper presents a disposable power generator for microfluidic devices; the power generator has a tubular PEMFC and a $H_2$ generator. The tubular PEMFC has a tubular MEA (diameter: 1.52 mm) that is supported by a spiral wire electrode. The $H_2$ generator supplied $H_2$ to the tubular PEMFC; $H_2$ was generated via the reaction of Al foil (27 mg) and 5 M NaOH (0.12 ml). The open circuit voltage and power density of a unit cell of the tubular PEMFC were 0.81 V and $16.4\;mW/cm^2$ (0.35 V), respectively. The $H_2$ generator generated 11.6 ml $H_2$ for 15min. The power generator was continuously operated for 15 min at 0.64 mW (0.71 V) and for 10 min at 1.06 mW (0.46 V). We experimentally verified that it is feasible to use the proposed power generator as a power source for microfluidic devices; in the experiment, an LED (2.5 mW; 1.8 V) was lit for 10 min by using three serially connected TPEMFCs and one $H_2$ generator.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.55-62
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• 2009

Location based Services in the ubiquitous computing environment, namely u-LBS, use very large and skewed spatial objects that are closely related to locational information. It is especially essential to achieve fast search, which is looking for POI(Point of Interest) related to the location of users. This paper examines how to search large and skewed POI efficiently in the u-LBS environment. We propose the Dynamic-level Grid based R-Tree(DGR-Tree), which is an index for point data that can reduce the cost of stationary POI search. DGR-Tree uses both R-Tree as a primary index and Dynamic-level Grid as a secondary index. DGR-Tree is optimized to be suitable for point data and solves the overlapping problem among leaf nodes. Dynamic-level Grid of DGR-Tree is created dynamically according to the density of POI. Each cell in Dynamic-level Grid has a leaf node pointer for direct access with the leaf node of the primary index. Therefore, the index access performance is improved greatly by accessing the leaf node directly through Dynamic-level Grid. We also propose a K-Nearest Neighbor(KNN) algorithm for DGR-Tree, which utilizes Dynamic-level Grid for fast access to candidate cells. The KNN algorithm for DGR-Tree provides the mechanism, which can access directly to cells enclosing given query point and adjacent cells without tree traversal. The KNN algorithm minimizes sorting cost about candidate lists with minimum distance and provides NEB(Non Extensible Boundary), which need not consider the extension of candidate nodes for KNN search.

• Journal of Life Science
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• v.25 no.11
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• pp.1319-1323
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• 2015

Aquaculture continues to be an ever-growing sector. However, high-density farming increases disease outbreaks due to deteriorating water quality and internal stress. To prevent disease, the most common method chemotherapy is using antibiotic administration. In this study, probiotic bacteria were isolated from Korean traditional foods, such a Gochu pickle and cutlassfish salted seafood. Various bacteria were isolated, and their 16S rDNA sequences were analyzed. The antimicrobial activities of four isolates from Gochu pickle and seven isolates from cutlassfish salted seafood were assayed, in addition to the antibacterial activity of culture pellet and supernatant. The antibacterial activity of the pellet was higher than that of the supernatant. Isolate JKM-2 showed the highest antibacterial activity against Streptococcus iniae (43 mm), S. parauberis (40 mm), S. mutans (35 mm), and Vibrio vuinificus (26.5 mm). The sequences of the isolated strains were compared with those of Bacillus subtilis (97.71%), B. tequilensis (97.71%), Brevibacterium halotolerans (97.71%), B. subtilis (97.63%), B. subtilis (97.63%), B. mojavensis (97.54%), B. vallismortis (97.46%), B. nanillea (97.45%), B. methylotrophicus (97.37%), and B. ssiamensis (97.37%). Future through analysis and new strains confirmed the bacterial cell material investigation of JKM-3, and to ensure sufficient stability, it is desired to verify the utility value as a substitute material for antibiotics by application to the form of the industry.