• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.374-390
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• 1993

Regeneration of periodontal tissue after a loss of attachment due to disease or trauma repesents an important issue in dentistry, and various bone graft materials have been used to regenerated lost periodontal tissue and restore proper fuctions. Among those, allografts have been extensively researched and widely used clinically, since they are known to possess an excellent osteoinduction capability and result in proper topography of alveolar bone. Regeneration of periodontal tissue in supraalveolar defects may be technically difficult. However, a large amount of regeneration has been observed by complete tissue coverage of involved teeth. In this study, supraalveolar defects in adult dogs were treated with periodontal surgery, decalcified freez-dried bone allograft, complete tissue coverage was attained, and effects on repair and regeneration of alveolar bone, cementum and periodontal ligament were studied. Exposure of premolar furcation of adult dogs was attained by removing marginal alveolar bone down to 5mm from CEJ, and root surfaces were planed with curettes. On the left side, defects were treated without any allograft(Control Group). On the right side, a DFDB was used(Experimental Group). In all groups, flaps were coronally positioned and sutured, completely submerging the treated defects. At two weeks, the crown were exposed 2-3mm. Healing progresses were histologically observed after eight weeks and the results were as follows : 1. Distance from CEJ to AJE was : $2.82{\pm}0.66mm$ in the control group, $1.71{\pm}0.51mm$ in experimental group, with significant differences between groups.(P<0.01) 2. Periodontal repair was : $2.18{\pm}0.66mm$ in the control group, $3.29{\pm}0.51mm$ in experimental group, with significant differences between groups.(P<0.01) 3. Connective tissue repair was : $1.43{\pm}0.52mm$ in the control group, $0.76{\pm}0.47mm$ in experimental group, with significant differences between groups.(P<0.01) Orientation of connective tissue fibers in relation to root surfaces was : mostly parallel in the control group, vertical or parallel or irregular in experimental group. 4. The amount of cementum formation was : $1.66{\pm}0.58mm$ in the control group, $2.86{\pm}0.66mm$ in experimental group, with significant differences between groups. 5. The amount of alveolar bone formation was : $0.76{\pm}0.72mm$ in the control group, $2.53{\pm}0.56mm$ in experimental group, with significant differences between groups.(P<0.01)

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.202-210
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• 2015

The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using $^{137}Cs$ irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological & Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.469-477
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• 2002

One of the major deficiencies of composite restorative resins is their insufficient resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent), Aelit flo(Bisco). Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights: (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(${\mu}m$) - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of the mass loss was in ascending order by AE, EL, TC, Z100. There was statistically significant difference of mass loss between AE, CL group and TC, Z100 group(p<0.05). 2. The sequence of the degree of degradation layer depth was in ascending order by AE, CL, TC, Z100. But there was no statistically significant difference of degree of degradation layer depth between AE and CL(p<0.05). 3. For the Si concentration, Z100 was the highest of all. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.71 p<0.05).

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.143-151
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• 2015

Many studies have investigated the airborne chlorides that can weaken the overall durability of the concrete structures due to the corrosion of steel materials, but most of the studies have aimed to examine weathering by exposing various construction materials to the actual oceanic environment. However, with the exposure test, it was difficult to find the threshold of precise corrosive amount of airborne chlorides due to diverse deteriorating environmental factors such as ultraviolet ray, acid rain, floating material from industrial pollution as well as airborne chlorides. Therefore, in this study, an airborne chloride simulator was set up, in oder to conduct a corrosion accelerating test for steels coated by five different finishing materials. As results, it was found that the corrosion began to be observed at $0.58{\sim}0.73mg/dm^2$ for no-coated steel, at $7.89{\sim}8.46mg/dm^2$for urethane-coated steel, at $57.95{\sim}69.48mg/dm^2$ for red lead-coated steel, and at $80.73{\sim}89.35mg/dm^2$ for stainless-coated steel, respectively. Hence, these specific data can be considered as the threshold ranges of corrosion for each coating material for steel.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.201-206
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• 2012

Benzo(a)pyrene is a polycyclic aromatic hydrocarbons (PAHs) whose metabolites are mutagenic and highly carcinogenic and is listed as a Group 1 carcinogen by the IARC. It has been found at variable concentrations in several foods and is associated with several factors during the process including contaminated raw materials, exposure of environment, and procedure of process or cooking. In this study, benzo(a)pyrene in 45 oriental medicines were determined by HPLC/FLD. The calibration curves of benzo(a)pyrene was linear over the concentration range of 0.5~40 ng/mL with correlation coefficient of above 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) of benzo(a)pyrene were 0.04 and 0.10 ${\mu}g/kg$. Benzo(a)pyrene in 3 samples out of 45 samples was not detected. The level of benzo(a)pyrene in 26 (57.7%), 8 (17.8%) and 7 (15.6%) samples was 0.1~0.5, 0.5~1.0 and 1.0~5.0 ${\mu}g/kg$, respectively. Especially, content of benzo(a)pyrene in Coptis Rhizome is the highest (5.97 ${\mu}g/kg$). In conclusion, these results suggest that could be applied to fundamental study and guideline on drying condition to decrease content of benzo(a)pyrene in oriental medicine.

• Tuberculosis and Respiratory Diseases
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• v.38 no.2
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• pp.135-142
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• 1991

We reviewed 15 cases of mesothelioma of the pleura, of which three cases were localized benign form and 12 cases were malignant diffuse form. The tumors were distributed equally in both sexes, and occured most commonly in fifth to seventh decades. The history of exposure to asbestos was present in only one case. The chief complaints were mainly chest pain and dyspnea. Associated symptoms were cough, sputum, hemoptysis, weight loss, anorexia, chill. On physical examination, unilateral, decreased breathing sound was main feature. The simple chest radiograph showed masses in all localized mesotheliomas (100%) and in 2 diffuse mesotheliomas (17%). 8 cases of diffuse mesotheliomas (67%) showed unilateral pleural effusions. Pleural effusions were mainly bloody (67%), and almost all were exudates. In all localized mesotheliomas, final diagnosis was made by open thoracotomy. In diffuse mesotheliomas, final diagnosis was made by open thoracotomy in 7 cases, chest wall mass biopsy in 2 cases, thoracoscopic biopsy in 1 case, pleural biopsy in 1 case, and pleural biopsy combined with axillary lymph node biopsy in 1 case. Localized mesotheliomas were treated by simple excision with good prognosis. In diffuse mesotheliomas, surgical treatment (pleuropneumonectomy, pleurectomy), chemotherapy, or radiotherapy, alone or in combination, were used with dismal prognosis. The prognostic factors were not found due to the small number of cases, incomplete follow up, and early drop out.

• The Korean Journal of Mycology
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• v.41 no.3
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• pp.192-196
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• 2013

Fungal development is largely affected by many environmental factors. In a model filamentous fungus Aspergillus nidulans, asexual development is promoted by exposure of light, presence of salt and non-fermentable sugars. In other hand, sexual development is largely induced by absence of light, fermentable sugars and hypoxic condition. Also, some important genes including veA and nsdD play positive roles in activating sexual development. Here, we reported that the effect of high concentration of $CO_2$ on developmental decision in A. nidulans. When wild-type $veA^+$ strain was cultured in normal condition, sexual and asexual development occurred in balanced manner. However, high concentration of $CO_2$ (~5%) strongly activated sexual development and inhibited asexual development. Furthermore, this $CO_2$ effect was controlled by the veA or nsdD gene. High $CO_2$ culture of $veA^-$ or $nsdD^-$ mutant didn't activate sexual development, suggesting that the activation of sexual development induced by high $CO_2$ cannot overcome the genetic requirement of sexual development such as veA or nsdD. Since 5% $CO_2$ is an important condition for human pathogenic fungi for surviving and adapting in human body, this developmental pattern of A. nidulans affected by $CO_2$ concentration may provide interesting clues for comparative study with human fungal pathogens including Aspergillus fumigatus.

• Journal of Life Science
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• v.22 no.10
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• pp.1399-1406
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• 2012

The present study was conducted to evaluate the effects of various extracts of Hizikia fusiforme on the anti-obesity effects in 3T3-L1 preadipocytes. We used H. fusiforme extracts from ethanol (EEHF), dichloromethane (CFHF), ethyl acetate (EAFHF), butanol (BFHF), and water (WFHF). Treatment with these extracts significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner as confirmed by a decrease in lipid droplet content through Oil Red O staining; this effect was higher in WFHF than in other extracts. The concentrations of cellular triglyceride were also reduced in 3T3-L1 cells by exposure with these extracts, especially when compared with the controls. Treatment with 200 ${\mu}g/ml$ of WFHF and CFHF caused approximately 42.6% and 23.7% reduction, respectively. In addition, the extracts of H. fusiforme significantly reduced the expression levels of key pro-adipogenic transcription factors, including peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) and CCAAT/enhancer binding proteins ${\alpha}$ (C/$EBP{\alpha}$) and C/$EBP{\beta}$ as compared with controls. Accordingly, our data indicated that WFHF has a preeminent effect on inhibition of adipocyte differentiation among various extracts, and H. fusiforme extracts may be an ideal candidate for obesity relief.

• Journal of Life Science
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• v.19 no.7
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• pp.871-877
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• 2009

We investigated the effects of sodium butyrate, a histone deacetylase inhibitor, on the cell cycle progression in human monocytic leukemia U937 cells. Exposure of U937 cells to sodium butyrate resulted in growth inhibition, G1 arrest of the cell cycle and induction of apoptosis in a dose-dependent manner as measured by MTT assay and flow cytometry analysis. The increase in G1 arrest was associated with the down-regulation in cyclin D1, E, A, cyclin-dependent kinase (Cdk) 4 and 6 expression, and up-regulation of Cdk inhibitors such as p21 and p27. Sodium butyrate treatment also inhibited the phosphorylation of retinoblastoma protein (pRB) and p130, however, the levels of transcription factors E2F-1 and E2F-4 were not markedly modulated. Furthermore, the down-regulation of phosphorylation of pRB and p130 by this compound was associated with enhanced binding of pRB and E2F-1, as well as p130 and E2F-4, respectively. Overall, the present results demonstrate a combined mechanism involving the inhibition of pRBjp130 phosphorylation and induction of Cdk inhibitors as targets for sodium butyrate that may explain some of its anti-cancer effects in U937 cells.

• Korean Journal of Health Education and Promotion
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• v.32 no.1
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• pp.1-10
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• 2015

Objectives: This study evaluated the effects and relevant factors of community-based education and advocacy intervention on stroke awareness among the general population. Methods: The study enrolled 505 community-dwelling adults aged 19 years or older who completed a survey before and after a community-based intervention held between May 2014 and December 2014. Trained staff collected data about knowledge of five stroke warning signs, emergency response, golden window of time (${\leq}3h$), and demographics. Results: After the intervention, public awareness of all five stroke warning signs increased significantly from 26.5% to 33.9% (p=0.011). Public awareness of the golden window of time also increased significantly from 70.1% in April 2014 to 75.8% in December 2014 (p=0.040). In a multivariate logistic regression analysis, older age, higher education level, and exposure to stroke-related public service announcements or educational materials were significant predictors of knowledge of all five warning signs for stroke. Conclusions: Comprehensive community-based intervention is effective for improving public awareness of the warning signs of stroke and the golden window of time.