• The Journal of Advanced Prosthodontics
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• v.2 no.2
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• pp.33-38
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• 2010

PURPOSE. Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS. 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS. The means and standard deviations of the marginal fit were $61.52{\pm}2.88{\mu}m$ for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and $83.15{\pm}3.51{\mu}m$ after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of $62.22{\pm}1.78{\mu}m$ before porcelain veneering and $82.03{\pm}1.85{\mu}m$ after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION. The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.467-476
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• 2009

The aim of this study was to measure the dentinal tubular fluid flow (DFF) during and after amalgam and composite restorations. A newly designed fluid flow measurement instrument was made. A third molar cut at 3 mm apical from the CEJ was connected to the flow measuring device under a hydrostatic pressure of 15 $cmH_2O$. Class I cavity was prepared and restored with either amalgam (Copalite varnish and Bestaloy) or composite (Z-250 with ScotchBond MultiPurpose: MP, Single Bond 2: SB, Clearfil SE Bond: CE and Easy Bond: EB as bonding systems). The DFF was measured from the intact tooth state through restoration procedures to 30 minutes after restoration, and re-measured at 3 and 7days after restoration. Inward fluid flow (IF) during cavity preparation was followed by outward flow (OF) after preparation, In amalgam restoration, the OF changed to IF during amalgam filling and slight OF followed after finishing. In composite restoration, application CE and EB showed a continuous OF and air-dry increased rapidly the OF until light-curing, whereas in MP and SB, rinse and dry caused IF and OF, respectively. Application of hydrophobic bonding resin in MP and CE caused a decrease in flow rate or even slight IF. Light-curing of adhesive and composite showed an abrupt IF. There was no statistically significant difference in the reduction of DFF among the materials at 30 min. 3 and 7 days after restoration (p > 0.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3405-3416
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• 2012

The purpose of this study was to find out the effects of music rope-skipping on health fitness, blood lipids and growth-related factors in male middle school students. For this purpose, twenty subjects were participated in this study and the participants were 'After School Class' boys in B middle school located in Gimhae City. They divided into exercise group(n=10) and control group(n=10). Exercise group conducted 45minutes per a day, four times a week for 12 weeks. And the control group continued their normal life. The results were as follows; First, in exercise group, lean body mass, muscular strength, muscular endurance, cardiovascular endurance and flexibility were all significantly increased after program execution. But %body fat was significantly decreased. In control group, muscular strength, muscular endurance and cardiovascular endurance were significantly increased. There were significant differences in lean body mass, %body fat, muscular strength and flexibility between two groups after program execution. Second, in exercise group, HDL-C was significantly increased after program execution. In control group, TG was significantly decreased. But HDL-C was significantly increased. There were no significant differences in all blood lipids(TC, TG, HDL-C and LDL-C) between two groups after program execution. Third, in exercise group, GH and IGF-I were significantly increased after program execution. In control group, IGF-I was significantly decreased. There were significant differences in IGF-I between two groups after program execution. These results indicate that music rope-skipping is effective to improve lean body mass, muscular strength, flexibility, GH and IGF-I in normal middle school male students.

• Korean Journal of Dental Materials
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• v.44 no.3
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• pp.197-206
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• 2017

The hardening effect by ice-quenching after oxidation of a Pd-Ag-Sn-Au metal-ceramic alloy during porcelain firing simulation was investigated by means of hardness test, field emission scanning electron microscopic observations, and X-ray diffraction analysis. The hardness decreased by ice-quenching after oxidation, which was induced by the homogenization of the ice-quenched specimen. The decreased hardness by ice-quenching after oxidation was recovered from the wash stage which was the first stage of the remaining firing process for bonding porcelain. After wash stage, the hardness of the ice-quenched specimens decreased during the subsequent porcelain firing process. But the final hardness of the ice-quenched specimens after oxidation was higher than that of the specimens cooled at stage 0 after oxidation. The increase in hardness of the specimens during the first firing process was caused by the lattice strains generated at the interface between the face-centered cubic Pd-Ag-rich matrix and the face-centered tetragonal Pd3(Sn, Ga, In) precipitate. The decrease in hardness of the specimens during the remaining firing process was caused by the microstructural coarsening.

• Tribology and Lubricants
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• v.36 no.4
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• pp.244-252
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• 2020

Materials manufactured by powder metallurgy (PM) are widely used in various applications such as water pump, shock absorber, and airplane components due to the reduction in the cost and weight. In this study, tribological properties of carbon steel subjected by surface treatment were investigated. The main purpose is to increase the strength and improve the tribological properties by reducing pores that formed by PM. Moreover, the surface treatment was carried out at room and high temperatures (RT and HT). The surface roughness of the untreated (NON) and treated (AFTER) samples was measured. It was found that the surface roughness was reduced after both the RT AFTER and HT AFTER compared to RT NON sample. The tribological properties of the samples were performed against bearing steel ball under dry conditions. The friction coefficient of the RT NON samples was reduced by 22% and 56% RT AFTER and HT AFTER, respectively. The wear volume of the RT NON sample was also reduced by 43% and 87% RT AFTER and HT AFTER, respectively. Tribocorrosion tests were also performed and it was found that the surface of the RT AFTER, HT AFTER samples was less corroded compared to RT NON sample. The HT AFTER sample demonstrated a relatively higher corrosion potential in comparison with the RT AFTER samples. Hence, it was confirmed that after surface modification the surface roughness and hardness of the samples were significantly improved resulting in improvement in tribological and tribocorrosion behaviors of PM carbon steel.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.3
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• pp.101-109
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• 2011

The purpose of this article is to introduce the Sports, Play, and Active Recreation for Kids (SPARK) physical education curriculum. SPARK is a model for health-related, research-based and evidence-based physical education programs in the United States. The outcome of school physical education can relate to public health, but there exists few evidence-based physical education programs reporting health-related variables. School physical education can provide more opportunities for children and adolescents to be physically active and to learn more about healthy lifestyles. However, physical education programs have been cut and eliminated due to lack of funding in the U.S. as in South Korea. Although facing these problems, SPARK programs have been implemented in over 50% of schools, after school programs and coordinated school health programs in the U.S. This article reviewed: (a) background information of the SPARK program, (b) examples of effective interventions, and (c) methods of dissemination to schools nationally in the U.S. The methods showed in SPARK may use as a model for researching, developing and implementing new physical education(PE) program and after school programs in Korea.

• Tuberculosis and Respiratory Diseases
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• v.77 no.6
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• pp.262-265
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• 2014

The combination chemotherapy of irinotecan with 5-fluorouracil and leucovorin (FOLFIRI regimen) was recently proven to be beneficial in patients with advanced colorectal cancer. Pulmonary toxicity is very rare in adverse effects of irinotecan. No case of organizing pneumonia (also known as bronchiolitis obliterans organizing pneumonia) associated with FOLFIRI chemotherapy has been reported. We experienced a case of a 62-year-old man who presented persistent dry cough and progressive dyspnea after receiving chemotherapy with FOLFIRI regimen. After surgical lung biopsy, the patient was diagnosed with FOLFIRI chemotherapy-induced organizing pneumonia which was successfully treated with steroid therapy.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.61-66
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• 2007

Trichloroethylene (TCE) is an unsaturated chlorinated hydrocarbon in the form of a colorless, volatile liquid, which is used as an industrial organic solvent for spot removal and for metal degreasing. In general, the primary complications of TCE poisoning result from involvement of the central nervous and respiratory systems, including aspiration pneumonia. A case is reported of a 54-year-old man who presented in a comatose state after accidental ingestion of 100 ml of TCE, and who recovered after conservative treatment and mechanical ventilation. We discuss this case and present a literature review.

• Clinical and Experimental Pediatrics
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• v.56 no.1
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• pp.1-7
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• 2013

School bullying has become a major social problem in Korea after the emergence of media reports on children who committed suicide after being victimized by bullies. In this article, we review the characteristics of bullying, and investigate the role of the pediatrician in the prevention of and intervention against bullying and school violence. Bullying can take on many forms such as physical threat, verbal humiliation, malicious rumors, and social ostracism. The prevalence of bullying in various countries is approximately 10% to 20%. In Korea, the prevalence of school violence is similar but seems to be more intense because of the highly competitive environment. From our review of literature, we found that children who were bullied had a significantly higher risk of developing psychosomatic and psychosocial problems such as headache, abdominal pain, anxiety, and depression than those who were not bullied. Hence, it is important for health practitioners to detect these signs in a child who was bullied by questioning and examining the child, and to determine whether bullying plays a contributing role when a child exhibits such signs. Pediatricians can play an important role in the prevention of or intervention against school violence along with school authorities, parents, and community leaders. Moreover, guidelines to prevent school violence, such as the Olweus Bullying Prevention Program, KiVa of the Finish Ministry of Education, and Connected Kids: Safe, Strong, Secure of the American Academy Pediatrics, should be implemented.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.363-368
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• 2015

The pharmacokinetics of florfenicol were studied in healthy and vibriosis-infected large yellow croaker (Pseudosciaena crocea) following administration of a single oral dose of $20mg{\cdot}kg^{-1}$ at $25{\pm}2^{\circ}C$. After oral administration, florfenicol levels in tissues (liver, kidney, muscle, serum, and skin) were analyzed using high-performance liquid chromatography. A two-compartment open model was used to describe the pharmacokinetics of florfenicol following oral administration. Compared to the healthy group, the absorption rate of vibriosis-infected fish significantly decreased, peak-time ($T_{max}$) delayed, maximum concentration ($C_{max}$) declined, total body clearance decreased, the elimination half-life ($T_{1/2{\beta}}$) was extended, and the area under the curve increased. These results indicate that a $20mg{\cdot}kg^{-1}$ oral dose of florfenicol administered once daily continuously for 4 or 5 days can be used for the treatment of Vibrio alginolyticus infection in large yellow croaker (Pseudosciaena crocea).