• Animal Bioscience
• /
• v.34 no.4
• /
• pp.724-733
• /
• 2021

Objective: The objectives of this study were to investigate the direct antioxidative effect of 90 Kda heat shock protein (Hsp90) obtained from duck muscle. Methods: The interaction of Hsp90 with phospholipids and oxidized phospholipids was studied with surface plasmon resonance (SPR), and their further oxidation in the presence of Hsp90 was evaluated with thiobarbituric acid reactive substances (TBARS) assay. The scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) was measured, and the electron paramagnetic resonance (EPR) spectroscopy in combination with 5-tert-Butoxycarbonyl-5-methyl-1-pyrroline-N-oxide and 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) was utilized to determine the abilities of Hsp90 in scavenging hydroxyl and PTIO radicals. Results: SPR showed Hsp90 could bind with both phospholipids and oxidized phospholipids, and prevent their further oxidation by the TBARS assay. The DPPH and ABTS scavenging activity increased with Hsp90 concentration, and could reach 27% and 20% respectively at the protein concentration of 50 μM. The EPR spectra demonstrated Hsp90 could directly scavenge ·OH and PTIO· radicals. Conclusion: This suggests that Hsp90, a natural antioxidant in meat, may play an important role in cellular defense against oxidative stress, and may have potential use in meat products.

• Progress in Superconductivity and Cryogenics
• /
• v.12 no.4
• /
• pp.17-19
• /
• 2010

In this work, the optimized process condition of chemical solution deposition which is used to planarize the surface of the metal tape (which is used to grow IBAD-MgO texture template) was investigated. $Y_2O_3$ films were dip-coated on the surface of the unpolished metal tape as the seed and barrier layer. The effects of $Y_2O_3$ concentration of the solution (0.5wt.%, 1.3wt.%, 2.8wt.%, 5.6wt.%) and the number of coatings on the surface morphology and barrier capability against the diffusion from the metal tape were examined. The surface morphology and the thickness of the film were observed using the scanning electron microscope and the atomic force microscope. The presence of elements in metal tape on the film surface was analyzed using the auger electron spectroscopy. The $Y_2O_3$ film thickness increases with increasing the $Y_2O_3$ concentration in the solution, and the surface became smoother with increasing the number of coating cycles. The best result was obtained from the $Y_2O_3$ film coated 4 cycles using 2.8wt.% solution.

• Journal of Periodontal and Implant Science
• /
• v.25 no.3
• /
• pp.539-556
• /
• 1995

Periodontal therapeutic modalities should be re-establishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, periodontal ligament cells must selective migrate to the deneded root surface, attached and proliferated it. Local pH concentration is one of the most factors that periodontal regeneration. The aims of this study were to examine on biological effects of pH to the human periodontal ligament cells in vitro, especially on the cell morphology, attachment, activity, vitality and viability. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Immediately after extraction, any soft tissue adhering to the cervical parts of the roots was carefully removed with a sterile curette. To produce different pH levels in the media, Eagle's MEM was adjusted from pH 6.6 to 8.2 in 0.2 intervals with 1 M NaOH and 1 N HCl. After cultivation, Then, Periodontal ligament cells were cultured at pH ranging from 6.6-8.2. attachment assay was done at 1, 2 day incubation and activity assay was done at 1, 2, 3 day incubation. The experiments were evaluated by scaning electron microscopic techniques (HITACHIX-650 Scaning Electron Microanalyzer, Tokyo, Japan), MTT assay, and the cultured periodontal ligament cells were fixed in neutral formalin for 24 hours and immunohistochemically processed by PCNA for proliferating ability. The surviving cells in the medium showed slightly increased volume and widening intercellular distances at low concentration of pH than control group (pH 7.4), and apparently shrinkage at high concentration of pH than control group (pH 7.4). The results of the statistical analysis from the experiment on attachment, vitality and viability were as follows. Attachment of periodontal ligament cells at 1st and 2nd day, similar attachment rate of low concentration pH compared with control value (pH 7.4). But above pH 8.0, attachment rate were statistically significant decrease from control value(P<0.05). Periodontal ligament cell's activities were maximum at pH 7.6 by MTT assay. Similar with control value at low concentration of pH. But, the activities were statistically significant decrease at high concentraration of pH(P<0.05). Cellular proliferating rate (PCNA index) were statistically significant decrease from control value at low and high concentration of pH(p<0.05). This results suggested that hjgh concentration pH, in other words, alkali pH was cytotoxic effects on human periodontal ligament cells in vitro.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.39.2-39.2
• /
• 2010

In this work we have investigated electrical and optical properties of interface for ITO/Si with shallow doped emitter. The ITO is prepared by DC magnetron sputter on p-type monocrystalline silicon substrate. As an experimental result, The transmittance at 640nm spectra is obtained an average transmittance over 85% in the visible range of the optical spectrum. The energy bandgap of ITO at oxygen flow from 0% to 4% obtained between 3.57eV and 3.68eV (ITO : 3.75eV). The energy bandgap of ITO is depending on the thickness, sturcture and doping concentration. Because the bandgap and position of absorption edge for degenerated semiconductor oxide are determined by two competing mechanism; i) bandgap narrowing due to electron-electron and electron-impurity effects on the valance and conduction bands (> 3.38eV), ii) bandgap widening by the Burstein-Moss effect, a blocking of the lowest states of the conduction band by excess electrons( < 4.15eV). The resistivity of ITO layer obtained about $6{\times}10^{-4}{\Omega}cm$ at 4% of oxygen flow. In case of decrease resistivity of ITO, the carrier concentration and carrier mobility of ITO film will be increased. The contact resistance of ITO/Si with shallow doped emitter was measured by the transmission line method(TLM). As an experimental result, the contact resistance was obtained $0.0705{\Omega}cm^2$ at 2% oxygen flow. It is formed ohmic-contact of interface ITO/Si substrate. The emitter series resistance of ITO/Si with shallow doped emitter was obtained $0.1821{\Omega}cm^2$. Therefore, As an PC1D simulation result, the fill factor of EWT solar cell obtained above 80%. The details will be presented in conference.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.2
• /
• pp.89-95
• /
• 1995

The structure of boron ion-implanted pn junctio in the vacancy-doped p-type HgCdTe was investigated with the differential Hall measurement. The as-implanted junction showed the electron concentration as high as 1${\times}10^{18}/cm^{3}$ and the junction depth of 0.6.mu.m. When the HgCdTe junction was heated in oven, the electron concentration near the junction decreased and the junction depth increased as the annealing temperature and time increased. The junction structure after the thermal annealing was n$^{+}$/n$^{-}$/p. For the 200.deg. C 20min annealed sample, the electron mobility was 10$^{4}cm^{2}/V{\cdot}$s near the surface(n$^{+}$), and was larger thatn 10$^{5}cm^{2}/V{\cdot}$s near the junction(n$^{+}$). The junction formation mechanism is conjectured as follows. When HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms near the surface. The displaced Hg vacancies diffuse in easily by the thernal treatment and a fill the Hg vacancies in the p-HgCdTe substrate. With the Hg vacancies filled completely, the GfCdTe substrate becomes n-type because of the residual n-type impurity which was added during the wafer growing. Therefore, the n$^{+}$/n$^{-}$/p regions are formed by crystal defects, residual impurities, and Hg vacancies, respectively.

• Journal of Plant Biology
• /
• v.37 no.2
• /
• pp.231-236
• /
• 1994

The effect of $Cd^{2+}$ on the electron transport rate of PSI and PSII was investigated in isolated spinach chloroplasts. In photosystem II, the rate of electron transport was decreased as the concentration of $Cd^{2+}$ was increased from 1 to $100\;\mu\textrm{M}$. The inhibitory effect of $Cd^{2+}$ was reduced when diphenylcarbazide was added to the reaction medium, indicating that $Cd^{2+}$ affects primarily psn oxygen evolving complexes of thylakoid membrane. The inhibitory effect of $Cd^{2+}$ was reduced when $Mn^{2+}\;and\;Ca^{2+}$ were added to the reaction medium, but the inhibitory effect was not fully relieved. Although the activity of psn was decreased significantly by the treatment of $50\;\mu\textrm{M}\;Cd^{2+}$, Fv/Fm was decreased slightly. However, the treatment of $100\;\mu\textrm{M}\;Cd^{2+}$ resulted in the marked decrease of Fv/Fm. In photosystem I, the rate of electron transport decreased as the concentration of $Cd^{2+}$ was increased from 0.2 to 3.2 mM. The inhibitory effect of $Cd^{2+}$ was decreased when the chloroplast treated with $Cd^{2+}$ was washed by centrifugation.gation.

• Journal of the Korean Vacuum Society
• /
• v.14 no.3
• /
• pp.153-158
• /
• 2005

The effective mean free path model was adopted to examine the thickness effect on the thermoelectric properties of flash-evaporated n-type $Bi_2Te_{2.4}Se_{0.6}$ thin films. Annealing effects on the electron concentration and mobility were also studied, and their variations were analyzed in conjunction with antisite defects. Seebeck coefficient and electrical resistivity versus inverse thickness showed a linear relationship, and the mean free path was found to be $5120\AA$ Electron mobility was increased by annealing treatment and electron concentration was decreased considerably due to reduction of antisite defects, so that electrical conductivity was decreased and Seebeck coefficient was increased. When annealed at 473k for 1 hour, Seebeck coefficient and electrical conductivity were $-200\;\mu V/k\;and\;510\omega^{-1}cm^{-1}$, respectively. Therefore, the thermoelectric power factor was improved to be $20\times10^{-4}\;W/(mK^2)$.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.872-881
• /
• 2012

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 $log_{10}$, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GC-MS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.6
• /
• pp.391-396
• /
• 2012

The destruction study of $NF_3$ gas emitted from the semiconductor industry is performed with electron-beam technology. Absorbed dose (kGy) and current ranged from 0 (0) to 400 kGy (20 mA). The concentration of $NF_3$ gas ranged from 500 to 2,000 ppm. In order to assess the effect of a residence time on DRE (Destruction and Removal Efficiency, %), experiments also conducted at different irridiation times of 5 sec, 10 sec, 15 sec and 20 sec respectively. As absorbed dose and current increased, DRE of $NF_3$ was also increased. However, DRE (%) of $NF_3$ decreased with increasing the concentration of $NF_3$ gas. The DRE of $NF_3$ was about 90% at an absorbed dose of 400 kGy.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.475-481
• /
• 2013

By using ionic liquid 1-hexylpyridinium hexafluorophosphate ($HPPF_6$) based carbon ionic liquid electrode (CILE) as the substrate electrode, a $CoMoO_4$ nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/$CoMoO_4$-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with $CoMoO_4$ nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (${\alpha}$) and electron transfer rate constant ($k_s$) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 $s^{-1}$, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol $L^{-1}$ with the detection limit as 0.036 mmol $L^{-1}$ ($3{\sigma}$), and the reduction of $H_2O_2$ in the concentration range from 0.12 to 397.0 ${\mu}mol\;L^{-1}$ with the detection limit as 0.0426 ${\mu}mol\;L^{-1}$ ($3{\sigma}$).