• Journal of the Korean Ceramic Society
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• v.20 no.4
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• pp.289-296
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• 1983

The Wetting of fusion cast $Al_2O_3$ brick and $Al_2O_3 -ZrO_2$ brick by liquid Ag was studied by the sessile drop technique in Ar atmosphere. In this experiment the specimens were photographed per 2$0^{\circ}C$with increasing temperature from 96$0^{\circ}C$ melting point of Ag. And the method of photographing was carried out by shadow technique. The cosine of the contact angle increased linearly with increasing temperature in both systems. And the relation between the cosine of the contact angle and the temperature was Cos$\theta$=1.132+$0.75{\times}10^{-3}T$ for $Al_2O_3$ brick and Cos$\theta$=-1.706+$1.125{\times}10^{-3}T$ for $Al_2O_3 -ZrO_2$ brick In both systems the contact angle decreased as the surface of substrate became smoother. The work of adhesion which was 503.5ergs/$cm^2$ for $Al_2O_3$brick and 393.6 ergs/cm2 for $Al_2O_3 -ZrO_2$ brick at 96$0^{\circ}C$ increased parabolically with increasing temperature in both system.

• BMB Reports
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• v.40 no.1
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• pp.107-112
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• 2007

To study the functioning of HSP70 in Escherichia coli, we selected NtHSP70-2 (AY372070) from among three genomic clones isolated in Nicotiana tabacum. Recombinant NtHSP70-2, containing a hexahistidine tag at the amino-terminus, was constructed, expressed in E. coli, and purified by $Ni^{2+}$ affinity chromatography and Q Sepharose Fast Flow anion exchange chromatography. The expressed fusion protein, $H_6NtHSP70$-2 (hexahistidine-tagged Nicotiana tabacum heat shock protein 70-2), maintained the stability of E. coli proteins up to 90$^{\circ}C$. Measuring the light scattering of luciferase (luc) revealed that NtHSP70-2 prevents the aggregation of luc without ATP during high-temperature stress. In a functional bioassay (1 h at 50$^{\circ}C$) for recombinant $H_6NtHSP70$-2, E. coli cells overexpressing $H_6NtHSP70$-2 survived about seven times longer than those lacking $H_6NtHSP70$-2. After 2 h at 50$^{\circ}C$, only the E. coli overexpressing $H_6NtHSP70$-2 survived under such conditions. Our NtHSP70-2 bioassays, as well as in vitro studies, strongly suggest that HSP70 confers thermo-tolerance to E. coli.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.150-155
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• 1988

In order to produce L-lysine from cellulosic substrates by the intergeneric protoplast fusion between cellulolytic bacteria, Cellulomonas flavigena KFCC31221 and amino acid producing bacteria, Brevibacterium flavum ATCC14067, Corynebacteriurn glutamicum ATCC13032, conditions for protoplast formation and regeneration of these strains were investigated. After the strains were mutated with 500$\mu\textrm{g}$/$m\ell$ N-methyl-N'-nitro N-nitrosoguanidine for 30 min and the mutants were enriched by treating 300$\mu\textrm{g}$/$m\ell$ penicillin-G for 2 hrs, B. flavum Hse- Str$^{r}$ , C. glutamicum Met$^{-}$Thr$^{-}$ Rif$^{r}$ and Cellulomonas flavigena Thr$^{-}$Val$^{-}$Kan$^{r}$ were isolated. The rate of protoplast formation ranged from 95 to 98% when strains were treated at the concentration of 500$\mu\textrm{g}$/$m\ell$ of lysozyme, pH 6.5, 33$^{\circ}C$, for 6 hrs. in Tris- malate buffer supplemented with 0.4M sucrose as osmotic stabilizer. Approximately 30-33% protoplast was regenerated on the regeneration complete medium(RCM) containing 1.5% agar and 0.5M sodium succinate overlaid with the same medium except 0.7% agar.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.83-90
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• 2018

In this study, zeolite (Z-C2) was synthesized using a fusion/hydrothermal method on coal fly ash (FA) discharged from a thermal power plant in the Ulsan area and then analyzed via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The Z-C2 was characterized in terms of mineralogical composition and morphological analysis. The XRD results showed that its peaks had the characteristics of Na-A zeolite in the range of $2{\theta}$ of 7.18~34.18. The SEM images confirmed that the Na-A zeolite crystals had a chamfered-edge crystal structure almost identical to that of the commercial zeolite. The adsorption kinetics of Cu, Co, Mn and Zn ions by Z-C2 were described better by the pseudo-second-order kinetic model more than by the pseudo-first-order kinetic model. The Langmuir model fitted the adsorption isotherm data better than the Freundlich model did. The maximum adsorption capacities of Cu, Co, Mn and Zn ions obtained from the Langmuir model were in the following order : Cu (94.7 mg/g) > Co (77.7 mg/g) > Mn (57.6 mg/g) > Zn (51.1 mg/g). These adsorption capacities are regarded as excellent compared to those of commercial zeolite.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.206-214
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• 2017

In this study, measurement of thermophysical properties of materials at high temperatures was performed. This experiment employed a heater device to heat the material to a high temperature. The images of the specimen surface due to thermal load at various temperatures were recorded using charge-coupled device (CCD) cameras. Afterwards, the full-field thermal deformation of the specimen was determined using the digital image correlation (DIC) method. The capability and accuracy of the proposed technique are verified by two experiments: (1) thermal deformation and strain measurement of a stainless steel specimen that was heated to $590^{\circ}C$ and (2) thermal expansion and thermal contraction measurements of specimen in the process of heating and cooling. This research focused on two goals: first, obtaining the temperature dependence of the coefficient of thermal expansion, which can be used as data input for finite element simulation; and second, investigating the capability of the DIC method in measuring full-field thermal deformation and strain. The results of the measured coefficient of thermal expansion were close to the values available in the handbook. The measurement results were in good agreement with finite element method simulation results. The results reveal that DIC is an effective and accurate technique for measuring full-field high-temperature thermal strain in engineering fields such as aerospace engineering.

• BMB Reports
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• v.43 no.12
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• pp.824-829
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• 2010

Melanin synthesis is regulated by melanocyte specific enzymes and related transcription factors. $\beta$-carboline alkaloids including harmaline and harmalol are widely distributed in the environment including several plant families and alcoholic beverages. Presently, melanin content and tyrosinase activity were increased in melanoma cells by harmaline and harmalol in concentration- and time-dependent manners. Increased protein levels of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2 were also evident. In addition, immunofluorescence and Western blot analyses revealed harmaline and harmalol increased cAMP response element binding protein phosphorylation and microphthalmia-associated transcription factor expression. In addition to studying the signaling that leads to melanogenesis, roles of the p38 MAPK pathways by the harmaline and harmalol were investigated. Harmaline and harmalol induced time-dependent phosphorylation of p38 MAPK. Harmaline and harmalol stimulated melanin synthesis and tyrosinase activity, as well as expression of tyrosinase and TRP-1 and TRP-2 indicating that these harmaline and harmalol induce melanogenesis through p38 MAPK signaling.

• Molecules and Cells
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• v.21 no.2
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• pp.244-250
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• 2006

Gangliosides are receptors for various peptides and proteins including neuropeptides, ${\beta}$-amyloid proteins, and prions. Recently, the role of gangliosides in mucosal immunization has attracted attention due to the emerging interest in oral vaccination. Ganglioside GM1 exists in abundance on the surface of the M cells of Peyer's patch, a well-known mucosal immunity induction site. In the present study we identified a peptide ligand for GM1 and tested whether it played a role in immune induction. GM1-binding peptides were selected from a phage-displayed dodecapeptide library and one peptide motif, GWKERLSSWNRF, was fused to the C-terminus of enhanced green fluorescent protein (EGFP). The fusion protein, but not EGFP fused with a control peptide, was concentrated around Peyer's patch after incubation in the lumen of the intestine ex vivo. Furthermore, oral feeding of the fusion protein but not control EGFP induced mucosal and systemic immune responses against EGFP resembling Th2-type immune responses.

• IMMUNE NETWORK
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• v.12 no.6
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• pp.261-268
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• 2012

Respiratory syncytial virus (RSV) and influenza virus are the most significant pathogens causing respiratory tract diseases. Composite vaccines are useful in reducing the number of vaccination and confer protection against multiple infectious agents. In this study, we generated fusion of RSV G protein core fragment (amino acid residues 131 to 230) and influenza HA1 globular head domain (amino acid residues 62 to 284) as a dual vaccine candidate. This fusion protein, Gcf-HA1, was bacterially expressed, purified by metal resin affinity chromatography, and refolded in PBS. BALB/c mice were intranasally immunized with Gcf-HA1 in combination with a mucosal adjuvant, cholera toxin (CT). Both serum IgG and mucosal IgA responses specific to Gcf and HA1 were significantly increased in Gcf-HA1/CT-vaccinated mice. To determine the protective efficacy of Gcf-HA1/CT vaccine, immunized mice were challenged with RSV (A2 strain) or influenza virus (A/PR/8/34). Neither detectable viral replication nor pathology was observed in the lungs of the immune mice. These results demonstrate that immunity induced by intranasal Gcf-HA1/CT immunization confers complete protection against both RSV and homologous influenza virus infection, suggesting our Gcf-HA1 vaccine candidate could be further developed as a dual subunit vaccine against RSV and influenza virus.

• The Korean Journal of Mycology
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• v.18 no.2
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• pp.77-83
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• 1990

Factors influencing the fusion frequency of protoplasts were investigated with auxotrophic mutants of Pleurotus florida and Pleurotus ostreatus. Immediately after the polyethylene glycol (PEG) solution was added, the protoplasts adhered firmly and shrank. During the subsequent dilution with 0.6 M sucrose, the protoplasts regained their normal size and larger bodies were observed. Interspecific heterokaryons were obtained by fusion of the nutritionally complementing protoplasts. Hyphae of the heterokaryotic fusants formed true clamp connections. The optimum conditions were a total of 1 to 15 million protoplasts per ml, 30% polyethylene glycol 8000 solution with adjustment to pH 8.0 and 0.6 M sucrose stabilized regeneration medium. Other parameters such as $CA^{++}$, glycine, exposure time and temperature influenced mainly the viability of the protoplasts.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1469-1475
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• 2000

Objective : The goal of this study was to evaluate the clinical outcome of the posterior C1-2 transarticular screw fixation without C1-2 sublaminar wiring in atlantoaxial instability. Methods : Between Apr. 1995 and Feb. 2000, we used this technique in treat randomly selected 17 patients (11 men, 6 women) who had atlantoaxial instability. The causes of instability were : type II-A odontoid process fracture(10 cases) ; type II-P odontoid process fracture(1 case) ; Os odontoideum(2 cases) ; transverse ligament laxity due to rheumatoid disease(1 case) ; and, transverse ligament injury without bone fracture(3 cases). All cases were operated with posterior C1-2 transarticular screw fixation with 3.5mm cortical screw and interlaminar iliac graft without sublaminar wire fixation. The mean follow-up period was 28 months(5 to 58 months) and the mean age at the time of operation was 41 years(15 to 68 years). All Patients were allowed to ambulate with Philadelphia neck collar on the first post-operation day. Results : Bony fusion was successfully achieved in all cases demonstrated at 3-month follow-up studies. There was no operative mortality or morbidity. Conclusion : The authors conclude that the posterior transarticular screw fixation without C1-2 sublaminar wiring provide adequate stability with high bony union rate in atlantoaxial instability of various causes.