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Acid etching of glass-infiltrated zirconia and its biological response
Van Thi Vu,Gye-Jeong Oh2,Kwi-Dug Yun,Hyun-Pil Lim,Ji-Won Kim,Thao Phuong Thi Nguyen,Sang-Won Park 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.2
PURPOSE. The purpose of this study was to evaluate the influence of acid etching treatment on surface characteristics and biological response of glass-infiltrated zirconia. MATERIALS AND METHODS. A hundred zirconia specimens were divided into four groups depending on surface treatments: untreated zirconia (group Z); acid-etched zirconia (group ZE); glass-infiltrated zirconia (group ZG); and glass-infiltrated and acid-etched zirconia (group ZGE). Surface roughness, surface topography, surface morphology, and Vickers hardness of specimens were evaluated. For biological response test, MC3T3-E1 cell attachment and proliferation on surface of the specimens were examined. The data were statistically analyzed using one-way ANOVA and Tukey’s HSD test at a significance level of 0.05. RESULTS. Group ZGE showed the highest surface roughness (Ra = 1.54 μm) compared with other groups (P < .05). Meanwhile, the hardness of group Z was significantly higher than those of other groups (P < .05). Cell attachment and cell proliferation were significantly higher in group ZGE (P < .05). CONCLUSION. We concluded that effective surface roughness on zirconia could be made by acid etching treatment after glass infiltration. This surface showed significantly enhanced osteoblast cell response.
Effects of herbicide tolerance rice cultivation on microbial community in paddy soil
Sung-Dug Oh,Tae-Hun Ryu,Soo-In Sohn,Chang-Gi Kim,Kyoungwhan Back,Kijong Lee 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07
Rice (Oryza sativa) is the most important staple food of over half the world’s population. This study was conducted to evaluate the possible impact of transgenic rice cultivation on the soil microbial community. Microorganisms were isolated from the rhizosphere of GM and non-GM rice cultivation soils. Microbial community was identified based on the culture-dependent and molecular biology methods. The total numbers of bacteria, fungi, and actinomycete in the rhizosphere soils cultivated with GM and non-GM rice were similar to each other, and there was no significant difference between GM and non-GM rice. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM rice were Actinobacteria, Firmicutes, and Proteobacteria. The microbial communities in GM and non-GM rice cultivated soils were characterized using the denaturing gradient gel electrophoresis (DGGE). The DGGE profiles showed similar patterns, but didn’t show significant difference to each other. DNAs were isolated from soils cultivating GM and non-GM rice and analyzed for persistence of inserted gene in the soil by using PCR. The PCR analysis revealed that there were no amplified protox gene in soil DNA. These data suggest that transgenic rice does not have a significant impact on soil microbial communities, although continued research may be necessary.
Sung-Dug Oh,Ki-Jong Lee,Soo-In Sohn,Myung Ja Kang,Jong-Sug Park,Hyun Suk Cho,Tae-Hun Ryu 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07
Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnological companies. Commercialization of GM crops will be required the assessment of risk associated with the release of GM crops. In this study, we carried out to provide the molecular characterization of introduced T-DNA in transgenic rice T4 ~ T6 generation lines harboring a pepper MsrB2 gene under the control of stress inducible Rab21 promoter, as a part of biosafety evaluation for drought-tolerant transgenic rice (CaMsrB2). We identified the structure and sequence of transformation vector of T-DNA and analyzed insertion sites, flanking sequences, and generational stability of inserted T-DNA in transgenic rice lines. The transformation vector was consisted of right border, a drought-tolerant CaMsrB2 gene unit, a selectable marker herbicide resistance unit, and left border in a sequential order. Based on the adaptor-ligation PCR and whole genome sequence database, we confirmed that T-DNA was introduced at the position of 41,737,284 bp of chromosome No. 1. From the generational stability study, T-DNAs were stably inherited through the T4 to T6 generations, and also stable expression of bar gene from T-DNA was confirmed. These results will be filed to biosafety assessment document of CaMsrB2 rice.
Analysis of the width ratio and wear rate of maxillary anterior teeth in the Korean population
Oh, Yeon-Ah,Yang, Hong-So,Park, Sang-Won,Lim, Hyun-Pil,Yun, Kwi-Dug,Park, Chan The Korean Academy of Prosthodonitics 2017 The Journal of Advanced Prosthodontics Vol.9 No.2
PURPOSE. The purpose of this study was to compare the width ratio of maxillary anterior teeth according to age in the Korean population and to evaluate the maxillary central incisor width-to-length (W/L) ratio, given differences in age and gender. MATERIALS AND METHODS. Ninety-three Korean adults were divided into 3 groups (n = 31) by age. Group I was 20 - 39 years old, Group II was 40 - 59 years old, and Group III was over 60 years of age. After taking an impression and a cast model of the maxillary arch, the anterior teeth width ratio and central incisor W/L ratio were calculated from standard digital images of the cast models using a graph paper with a digital single lens reflex (DSLR) camera. The calculated ratios were compared among all groups and central incisor W/L ratio were analyzed according to age and gender. All comparative data were statistically analyzed with one-sample t-tests, one-way ANOVAs with Tukey tests, and independent t-tests. RESULTS. No significant differences in maxillary anterior teeth ratios were found among the age groups. The maxillary central incisor W/L ratios in Group III were the greatest and were significantly higher than those in the other groups. The central incisor W/L ratio of men was higher than that of women in Group II. CONCLUSION. Maxillary anterior teeth width ratios were similar in all age groups in the Korean population. The maxillary central incisor was observed as worn teeth in the group over 60 years of age, and a significant difference between genders was found in 40 to 50 year olds.
Molecular biological analysis of Bt-9 rice and its effect on Daphnia magna feeding
Sung-Dug Oh,Soo-Yun Park,Sang Jae Suh,Ancheol Chang 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10
Insect-resistant transgenic (Bt-9) rice was generated by inserting the mCry1Ac1 a modified gene from the soil bacterium Bacillus thuringiensis into the genome of a conventional variety of rice (Ilmibyeo). With regard to the potential problems of safety, the non-target organism evaluation is required as an essential element for the environmental risk assessment of genetically modified (GM) crops. For biosafety assessment, we studied the effects on survival of cantor Daphnia magna, a commonly used as a model organism in ecotoxicological studies. D. magna fed on Bt-transgenic rice (Bt-9) and its near non-GM counterparts (Ilmibyeo) grown in the same environment (100% ground rice suspension). The Bt-9 rice was comfirmed to have the insertion of T-DNA and protein expression by the PCR and ELISA analysis. Feeding study showed similar cumulative immobility and abnormal response of Daphnia magna between Bt-9 rice and Ilmibyeo. 48hr-EC50 values of Bt-9 and Ilmi rice showed 4,400 mg/L (95% confidence limits: 3861.01 ~ 5015.01 mg/L) and 5,564mg/L (95% confidence limits: 4780.03 ~ 6476.93 mg/L) respectively. The rice NOEC (No observed effect concentration) value for D. magna was suggested 1,620mg/L. We conclude that the tested Bt-9 and Ilmi similar cumulative immobility for D. magna the widely used model organism. We found out that there is strong possibility that the growth of Bt-9 didn’t affect to non-target insects.