• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3618-3624
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• 2012

Photodissociation dynamics of propiolic acid ($HC{\equiv}C-COOH$) at 212 nm in the gas phase was investigated by measuring rotationally resolved laser-induced fluorescence spectra of OH ($^2{\Pi}$) radicals exclusively produced in the ground electronic state. From the spectra, internal energies of OH and total translational energy of products were determined. The electronic transition at 212 nm responsible for OH dissociation was assigned as the ${\pi}_{C{\equiv}C}{\rightarrow}{\pi}^*{_{C=O}}$ transition by time-dependent density functional theory calculations. Potential energy surfaces of both the ground and electronically excited states were obtained employing quantum chemical calculations. It was suggested that the dissociation of OH from propiolic acid excited at 212 nm should take place along the $S_1/T_1$ potential energy surfaces after internal conversion and/or intersystem crossing from the initially populated $S_2$ state based upon the potential energy calculations and model calculations for energy partitioning of the available energy among products.

• Korean Journal of Microbiology
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• v.28 no.4
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• pp.311-317
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• 1990

Intraspecific and interspecific protoplast fusions in/between C. thermocellum and C. thermohydrosulfuricum were studied. Protoplast fusions were well induced in 30-40% PEG solution, however, their fusion frequencies were low level of 1.2*10$^{-7}$ for intraspecific fusion of C. thermocellum, $6.7*10^{-7}$ for C. thermohydrosulfuricum, and 4.2*10$^{-7}$ for interspecific fusion between above two Clostridia, respectively. Most fusants were unstable and segregated after 3 subcultures. Relatively stable intraspecific C. thermocellum fusant FTT17, intraspecific C. thermohydrosulfurecum fusant FSS22 and interspecific fusant FTS3, which were stable after several subcultures, were selected and properties of fusants were further investigated, Phenotypes of the fusants were similar with wild types mostly in cellular morphology, carbon source assimilation and enzyme activities. However they were differed in assimilation of pyruvic acid and sorbitol as carbon source. The DNA contents of fusants were slightly increased compared with wild types. Ethanol production by intraspecific and/or interspecific fusants was not increased, however, acetic acid production as byproduct was decreased or not detected, which indicates that industrial thermophilic anaerobes can be improved by means of protoplast fusion of two strains.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.5
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• pp.301-306
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• 2011

In this study, zeolite was synthesized by hydrothermal, fusion, and fusion/hydrothermal methods with fly ash, coal fly ash, and a waste catalyst discharged from thermal power plants and incinerator in Ulsan area. Coal fly ashes (CFAs) and a waste catalyst containing amounts of $SiO_2$ and $Al_2O_3$ ranging from 60.29 to 89.62 wt%. CFAs were mainly composed of quartz and mullite which were assayed by a XRD pattern. Zeolite could be synthesized by CFAs and the waste catalyst when all methods were used. Na-A zeolite (Z-C1, Z-C2, and Z-W5) are mainly synthesized by the fusion method from CFAs and the waste catalyst. Z-C1 and Z-C2 formed by-products, calcite peaks, which is caused by the content of CaO in CFAs and the addition of $Na_2CO_3$ for a synthetic process.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.21-26
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• 2012

Objective : To evaluate a new posterior atlantoaxial fixation technique using a nitinol shape memory loop as a simple method that avoids the risk of vertebral artery or nerve injury. Methods : We retrospectively evaluated 14 patients with atlantoaxial instability who had undergone posterior C1-2 fusion using a nitinol shape memory loop. The success of fusion was determined clinically and radiologically. We reviewed patients' neurologic outcomes, neck disability index (NDI), solid bone fusion on cervical spine films, changes in posterior atlantodental interval (PADI), and surgical complications. Results : Solid bone fusion was documented radiologically in all cases, and PADI increased after surgery (p<0.05). All patients remained neurologically intact and showed improvement in NDI score (p<0.05). There were no surgical complications such as neural tissue or vertebral artery injury or instrument failure in the follow-up period. Conclusion : Posterior C1-2 fixation with a nitinol shape memory loop is a simple, less technically demanding method compared to the conventional technique and may avoid the instrument-related complications of posterior C1-2 screw and rod fixation. We introduce this technique as one of the treatment options for atlantoaxial instability.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.95-102
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• 2020

Purpose:The aim of the present study was to evaluate the incidence of the second mesiobuccal (MB2) canal, root fusion, and C-shaped root canal configuration in the Korean maxillary first (MM1) and second (MM2) molars by analyzing cone-beam computed tomographic (CBCT) images. Materials and methods: Patients undergoing presurgical CBCT examination were included in the current study. The CBCT images of 1498 MM1 and 1742 MM2 from 1658 Korean patients were assessed to determine the incidence of a MB2 canal, the types of canal configurations, root fusion, and C-shaped root canal configurations. Further, the correlations between the incidence of MB2 canal and age, gender, and tooth position were analyzed. Results: The study population was relatively old (mean age: 66.1 years). The percentage of MB2 canals in MB roots was 60.1% and 28.0% in MM1 and MM2, respectively, with the most common configurations being Weine type III in MM1 and Weine type II in MM2. Additionally, the frequency of a MB2 canal decreased with age in both molars and was higher in men than in women in the MM1 only. Furthermore, root fusion was present in 2.3% and 26.2% of the MM1 and MM2, respectively, whereas C-shaped root canals were observed in 0.4% and 2.7% of the MM1 and MM2, respectively. Conclusion: The MB2 canal was found more frequently in the MM1, whereas root fusion and C-shaped root canals were both seen more frequently in the MM2.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.160-160
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• 2010

In this work, we investigate ohmic contacts to p-type GaN using a Pt/Cu/Au metallization scheme in order to achieve low resistance and thermally stable ohmic contact on p-GaN. An ohmic contact formed by a metal electrode deposited on a highly doped InGaN/GaN superlattice sturucture on p-GaN layer. The specific contact resistance is $1.56{\times}10^{-6}{\Omega}cm^2$ for the as-deposited sample, $1.35{\times}10^{-4}{\Omega}cm^2$ for the sample annealed at $250^{\circ}C$ and $6.88{\times}10^{-3}{\Omega}cm^2$ for the sample annealed at $300^{\circ}C$.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.505-510
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• 2000

The synthesis of pentahydroindanoisoquinoline (4) compound has been achieved via the cyclization of 2-(N-benzylamino)-5,6-difluoro-1-indanol (10a, 10b), which was prepared by condensation and reduction of 2-amino-1-indanol and benzaldehyde in ethanol. The stereochemistry of $H_{6a}$ and $H_{11b}$ of 9,10-difluoro-5,6,6a,7,11b-pentahydroindano[2,1-c]isoquinoline (4) was the trans B/C ring fusion.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.359-363
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• 1986

S. diastaticus hydrolysised $\alpha$-1.4 linkage of the starch and was known fermenting yeast strain, but poorly hydrolized $\alpha$-1.6 linkage of the starch. To improve the starch fermentation ability of yeast, we tried that protoplast fusion between S. diastaticus and C. tropicalis and finally two starins of fusant (FPDC42, FPDC43) were obtained. C. tropicalis well hydrolysis both $\alpha$-1.4 and $\alpha$-1.6 linkanges in the starch. The protoplast of parental auxotrophic cells were fused in the presence of 10mM CaCl$_2$ and 35% of polyethylene glycol (M. W. 4,000). The fusion frequency was 10$^{-5}$ to 10$^{-6}$. Properties of the fusants(genetic stability, assimilation of carbon sources, random spore formation, copper resistance, NaCl tolerance, DNA content, cell size and growth rate) were investigated.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.232-237
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• 2005

This study was conducted to elucidate the effects of NaOH fusion treatment on Na-P1 zeolite synthesis from fly ash and to evaluate its optimal condition. NaOH fusion treatment of fly ash led to Na-P1 zeolite with shorter reaction time and higher quality compared that of simple hydrothermal method. Mixed zeolite phases of Na-P1 and hydroxy sodalite were formed by the fusion treatment below $450^{\circ}C$, whereas only Na-P1 zeolite was formed above $550^{\circ}C$. Ratio of NaOH/fly ash, reaction times, fusion temperature and solid/liquid ratio strongly affected the kind and crystallinity of the zeolite formed. The CEC of Na-P1 zeolite formed at the optimum reaction conditions of NaOH/fly ash ratio 0.9 and solid/liquid ratio $1/5.0{\sim}1/7.5$ after NaOH fusion treatment at $550^{\circ}C$ for 2 hours was about $398cmol^+kg^{-1}$ which was 40% higher than those of control products. Therefore, it is clear that NaOH fusion treatment of fly ash in open system could lead to Na-P1 zeolite with high purity.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.365-373
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• 2000

The purpose of this study was to investigate the effects of the fusion pulses and fusion media on fusion rate and the development of embryos produced by somatic cell nuclear transfer in Hanwoo (Korean cattle). Nuclear donor cumulus and fetal fibroblast cells were cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at 38.5$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. The cumulus cell and cytoplast were fused using one pulse of 70 volts for 40$mutextrm{s}$, two pulses of 70 volts for 40$mutextrm{s}$ and one pulse of 180 volts for 15$mutextrm{s}$. The fetal fibroblast cell and cytoplast were fused using one pulse of 180 volts for 15$mutextrm{s}$ or 30$mutextrm{s}$. The cumulus cell and cytoplast were fused using mannitol and Zimmerman cell fusion medium (ZCFM) as a fusion medium. The fused embryos were activated after the fusion with 10 $\mu$M calcium ionophore for 5 min and 2 mM 6-dimethyl- aminopurine for 3 h. The nuclear transfer embryos were cultured in 500 ${mu}ell$ well of modified CR1aa supplemented with 3 mg/$m\ell$ BSA in th $\varepsilon$ four well dish cove red with mineral oil. After 3 days culture, culture medium was changed into modified CRlaa medium containing 1.5 mg/$m\ell$ BSA and 5% FBS for 4 days. The incubation environment was 5% $CO_2$, 5% $O_2$, 90% $N_2$ at 38.5$^{\circ}C$. When the cumulus cells were fused with enucleated oocytes by three different fusion pulses, one pulse of 180 volts for 15 $mutextrm{s}$ yielded the highest fusion rate and developmental rate to blastocyst among the pulses (P＜0.05). When the fetal fibroblast cells were fused with enucleated oocytes, one pulse of 180 volts for 30$mutextrm{s}$ yielded significantly higher fusion rate compared with that for 15 $mutextrm{s}$(P＜0.05). The present result indicates that the fusion rate between karyoplast and cytoplast was affected by the cell type and the optimal fusion condition was different according to cell type or size. When the fusion was conducted by the use of mannitol and ZCFM, the fusion rate was 71.2% and 65.8%, respectively. The developmental rates to blastocyst were 37.8% and 39.8%, respectively. There was no significant difference between two fusion media in the developmental rate of cumulus cell nuclear transfer embryos. These results indicate that optimal electric current should be selected according to cell type.