• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.125-131
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• 2011

Objectives: The purpose of this study was to evaluate the effect of surface treatment of FRC-Post on bonding strength to resin cements. Materials and Methods: Pre-surface treated LuxaPost (DMG), Rely-X Fiber Post (3M ESPE) and self adhesive resin cement Rely-X Unicem (3M ESPE), conventional resin cement Rely-X ARC (3M ESPE), and Rely-X Ceramic Primer (3M ESPE) were used. After completing the surface treatments of the posts, posts and resin cement were placed in clear molds and photo-activation was performed. The specimens were sectioned perpendicular to the FRC-Post into 2 mm-thick segments, and push-out strength were measured. The results of bond strength value were statistically analyzed using independent samples t-test and oneway ANOVA with multiple comparisons using Scheffe's test. Results: Silanization of posts affect to the bond strength in LuxaPost, and did not affect in Rely-X Fiber Post. Rely-X ARC showed higher value than Rely-X Unicem. Conclusions: Silanization is needed to enhance the bond strength between LuxaPost and resin cements.

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.686-692
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• 2001

Background : Outbreaks of multidrug-resistant tuberculosis(MDR-TB) are caused by the low rate of treatment response due to limitation in number of available drugs and high rates of adverse drug side-effects. This study analysed the risk factors for MDR-TB patients, who did not respond to treatment, with an aim to improve the rate of treatment response. Methods : Retrospective study of 111 MDR-TB patients at National Mokpo Tuberculosis Hospital from Jan. 1996 to Dec. 1998 was made. The patients were separated into two groups ; group I comprised of patients who were treated successfully and group II comprised of those were not treated successfully. In order to analyze the risk factors for treatment failure, differences between the two groups were compared and the confidence limit regarding the results were tested using an independent t-test. chi-square test and a Fisher's exact test. Results : The treatment failure rate of MDR-TB patients was 32% (36 patients), and treatment success rate 68%(75 patients). This study found no significant difference between two groups in terms of age, sex, family history, extent of the disease on the chest X-ray, the number of sensitive drugs in the treatment regimen, and the number of sensitive bactericidal drugs in the treatment regimen (p>0.05). However, a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used showed a significant difference(p<0.05). Conclusion : The rate of treatment failure in MDR-TB was increased by a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used. For improving the treatment response of MDR-TB, every effort should be made to reduce the drug resistance caused by failure of the first treatment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.245-251
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• 2005

When we design coastal and harbol facilities deepwater design wave and wind speed are the important design parameters. Especially, the analysis of these informations is a vital step for the point of disaster prevention. In this study, we made and an extreme value analysis using a series of deep water significant wave data arranged in the 16 direction and supplied by KORDI real-time wave information system ,and the wind data gained from Wan-Do whether Station 1978-2003. The probability distributions considered in this characteristic analysis were the Weibull, the Gumbel, the Log-Pearson Type III, the Normal, the Lognormal, and the Gamma distribution. The parameter for each distribution was estimated by three methods, i.e. the method of moments, the maximum likelihood, and the method of probability weight moments. Furthermore, probability distributions for the extreme data had been selected by using Chi-square and Kolmogorov-Smirnov test within significant level of 5%, i,e. 95% reliance level. From this study we found that Gumbel distribution is the most proper model for the deep water design wave height off the southwest coast of Korea. However the result shows that the proper distribution made for the selected site is varied in each extreme data set.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.177-183
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• 2008

Ac/Ds mutant lines of this study were transgenic rice plants, each of which harbored the maize transposable element Ds together with a GUS coding sequence under the control of a promoterless(Ds-GUS). We selected the mutants that were GUS expressed lines, because the GUS positive lines will be useful for identifying gene function in rice. One of these mutants was identified knock-out at Oszinc626(NP_001049991) gene, encoding a RING-H2 zinc-finger protein, by Ds insertion. In this mutant, while primary root development is normal, secondary root development from lateral root was very poor and seed development was incomplete compare with normal plant. RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, a few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. The consensus of the RING-H2(C3-H2-C3 type) domain for this group of protein is $Cys-X_2-Cys-X_{28}-Cys-X-His-X_2-His-X_2-Cys-X_{14}-Cys-X_2-Cys$. Oszinc626 encodes a predicted protein product of 445 amino acids residues with a molecular mass of 49 kDa, with a RING-zinc-finger motif located at the extreme end of the C-terminus. RT-PCR analysis indicated that the expression of Oszinc626 gene was induced by IAA, cold, dehydration, high-salinity and abscisic acid, but not by 2,4-D, and the transcription of Oszinc626 gene accumulated primarily in rice immature seeds, root meristem and shoots. The gene accumulation patterns were corresponded with GUS expression.

• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.132-138
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• 2011

Objectives: The purpose of this study was to evaluate curing degree of three dual-cure resin cements with the elapsed time in self-cure and dual-cure mode by means of the repeated measure of micro-hardness. Materials and Methods: Two dual-cure self-adhesive resin cements studied were Maxcem Elite (Kerr), Rely-X Unicem (3M ESPE) and one conventional dual-cure resin cement was Rely-X ARC resin cement (3M ESPE). Twenty specimens for each cements were made in Teflon mould and divided equally by self-cure and dual-cure mode and left in dark, $36^{\circ}C$, 100% relative humidity conditional-micro-hardness was measured at 10 min, 30 min, 1 hr, 3 hr, 6 hr, 12 hr and 24 hr after baseline. The results of micro-hardness value were statistically analyzed using independent samples t-test and one-way ANOVA with multiple comparisons using Scheffe's test. Results: The micro-hardness values were increased with time in every test groups. Dual-cure mode obtained higher micro-hardness value than self-cure mode except after one hour of Maxcem. Self-cured Rely-X Unicem showed lowest value and dual-cured Rely-X Unicem showed highest value in every measuring time. Conclusions: Sufficient light curing to dual-cure resin cements should provided for achieve maximum curing.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.445-458
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• 1998

The present study focused on the vegetation structure and dynamics of Betula davurica forest were to provide the information for management, distribution and utilization of B. davurica forest in Mt. Chiri national park, southern Korea. The layer structure of B. davurica forest were consist of tree layer(18 species), middle layer(29 species), shrub layer(43 species) and herb layer(68 species). According to the importance value of stratification of layers, In tree layer, B. davurica dominant the highest value of 123.97%, Alnus hirsuta 49.04., Castanea crenata 25.58%, Quercus serrata 25.02%, Stewartia koreana 14.49%, in middle layer were B. davurica 70.81%, Q. serrata 37.74%, Fraxinus rhynchophylla 25.35% Lindera erythrocarpa 24.52%, S. koreana 18.86%, shrub layer were Sasa borealis 28.28%, L. erythrocarpa 24.94%, Rhus trichocarpa, 20.42%, Stephanandra incisa 19.90% and herb layer Schizandra chinensis 18.51%, Aster scaber 12.26%. Disporum smilacinum 10.63% etc, respectively. Results of chi-square test statistics based on presence-absence parameters, the positively associated species pair were Quercus variablis - Q. acutissima, Stewartia koreana - Symplocos paniculata, Acer pseudo-sieboldianum - Quercus mongolica. And covariation was calculated based on quantitative measure of density. The results showed that the association and covariation values among species not agreed with each other. The frequency distribution of DBH Betula davurica species showed reverse J-shaped, therefore it's seems to retrain as a dominant species. When predicting succession in Betula davurica forest, it is seedling and saplings were not richness, succession was governed by competition of hardwood species of subtree and tree layer.

• Korean journal of applied entomology
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• v.14 no.2 s.23
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• pp.71-76
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• 1975

The study has been carried to find a proper site for seed potato production in Jeon Bug Province, Korea. Two fields, one at the alpine area (700-800 m sea level) in Muju county and the other at the plain area in Jeoniu, were chose for this study. Seed potatoes for the experiment were obtained from Alpine Experiment Station and from the traditional sources in Muju area. During the growing season the virus infection (Potato virus X,S,Y, and M) was detected by serolgical method. The average percent of virus infection on the original seed potatoes, which have been used as a seed source in Korea, was $50.5\%$, and the ratio of the infection for each of potato virus, Y, M and X was 34..87, 40.33, 41.00 and $87.10\%$, respectively. Infection percentage of virus at first year in Muju area was $11.7\%$ and those in Jeonju area was $18.95\%$. In case of potato virus Y, the most prevalent virus in Korea, lower Infection percentage $(6.45\%)$ was found in Muju area than in tile Jeonju area $(26.0\%)$ when the seed from Alpine Experiment Station was planted in both areas. The percentage of infected seed potato, Alpine Experiment Station$(41.75\%)$ was almost the same as those from the traditional sources in Muju $(42.17\%)$. The production of seed potato, however, was much better by the seeds from Alpine Experiment Station.

• Research in Plant Disease
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• v.28 no.4
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• pp.237-244
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• 2022

Chrysanthemum plants are one of the most economically important plants in South Korea. Both virus and viroid can cause diseases and economic damage to the plants. In this study, we investigated the detection of seven viruses and two viroids in 350 chrysanthemum plants cultivated in Yesan-gun, Chungcheongnam-do. Two viruses, chrysanthemum virus B (CVB) and tomato aspermy virus (TAV), and two viroids, chrysanthemum chlorotic mottle viroid (CChMVd) and chrysanthemum stunt viroid (CSVd), were detected in this study. The two viruses were detected in six samples and one sample, respectively. The two viroids were detected in 97 samples and 21 samples, respectively. The nucleotide sequences of the CVB-CN-Y, TAV-CN-Y, CChMVd-CN-Y, and CSVd-CN-Y obtained in this study showed 83.7-86.9%, 99.2-100.0%, 94.4-99.5%, and 95.7-99.7% identity, respectively, compared to their other strains/isolates. The CVB-CN-Y and TAV-CN-Y showed the greatest nucleotide sequence homology to CVB-GS1 and three TAV isolates (TAV-V, TAV-P, and TAV-ChJ), respectively. The CChMVd-CN-Y and CSVd-CN-Y showed the greatest nucleotide sequence homology to CChMVd-Horst and four CSVd isolates (Au1.1, K4pop, Sagae, and Tochigi), respectively. This study is the report on the infection rate of viruses and viroids in chrysanthemum plants cultivated in Yesan-gun in 2021.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.163-170
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• 2008

This experiment was conducted to determine the development of mixed organic fertilizer using photosynthetic bacteria and mass production of mixed microbial compound for the environment-friendly agriculture. Photosynthetic bacteria, Rhodobacter sp. SA16 was isolated from soil collected by plastic film house. The SA16 strain was identified based on 16S rDNA sequence analysis and it is closely related to Rhodobacter sp.(100% similarity). The mixed organic fertilizer using SA16 was made of $N-P_2O_5-K_2O=60-10-20\;g\;kg^{-1}$ with combined soybean cake, sesame cake, powdered blood, fish meal, powdered bones and red-yellow soil. The mixed organic fertilizer 0.45, 0.90 and 1.35 Mg $ha^{-1}$ application in Ihyeon series was treated based on soil testing for lettuce cultivation in plastic film house. These results showed that the yield was increased the 18 and 19%over control by the mixed organic fertilizer application 0.45 and 0.90 Mg $ha^{-1}$, respectively. In the physical properties of the soil, the porosity of mixed organic fertilizer 1.35 Mg $ha^{-1}$ treatment was highest at 58.8%. Our results clearly revealed that the organic fertilizer using Rhodobacter sp. SA16 and mass production of mixed strains could be a useful technology in pursuing environment-friendly agriculture.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.82-89
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• 2014

Purpose: The purpose of this study was to observe the change of viscoelastic properties of dental resin cements during polymerization. Materials and methods: Six commercially available resin cement materials (Clearfil SA luting, Panavia F 2.0, Zirconite, Variolink N, RelyX Unicem clicker, RelyX U200) were investigated in this study. A dynamic oscillation-time sweep test was performed with AR1500 stress controlled rheometer at $32^{\circ}C$. The changes in shear storage modulus (G'), shear loss modulus (G"), loss tangent (tan ${\delta}$) and displacement were measured for twenty minutes and repeated three times for each material. The data were analyzed using one-way ANOVA and Tukey's post hoc test (${\alpha}$=0.05). Results: After mixing, all materials demonstrated an increase in G' with time, reaching the plateau in the end. RelyX U200 demonstrated the highest G' value, while RelyX Unicem (clicker type) and Variolink N demonstrated the lowest G' value at the end of experimental time. Tan ${\delta}$was maintained at some level and reached the zero at the starting point where G' began to increase. The tan ${\delta}$and displacement of the tested materials showed similar pattern in the graph within change of time. The displacement of all 6 materials approached to zero within 6 minutes. Conclusion: Compared to other resin cements used in this study, RelyX U200 maintained plastic property for a longer period of time. When it completed the curing process, RelyX U200 had the highest stiffness. It is convenient for clinicians to cement multiple units of dental prostheses simultaneously.