• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1661-1665
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• 2004

Hard disk drives (HDD) in computer are used extensively as data storage capacity. The trend in the computer industry to produce smaller disk drives rotating at higher speeds requires an improved understanding of fluid motion in the space between disks. Laser sheet and digital camera was used for 2-dimensional visualization of the unsteady flow between co-rotating disks in air with a cylindrical enclosure (or shroud). Geometric parameters are gap height (H) between disks, and gap distance (G) between disk tip and shroud. The lobe-structured boundary between inner region and outer region was detected by inserted particles, and the number of dominant vortices was determined clearly It is found from flow visualization that the number of vortex cells can be correlated with Reynolds number based on H which is defined as $Re_H={\Omega}RH/v$ ranging from $7.96{\times}10^2$ to $1.43{\times}10^4$, and decreases as the disk speed increases. The lobe pattern by vortex cells is changed to a circular pattern for the wide gap than narrow one.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.524-531
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• 2018

Background: Fermented black ginseng (FBG) is produced through several cycles of steam treatment of raw ginseng, at which point its color turns black. During this process, the original ginsenoside components of raw ginseng (e.g., Re, Rg1, Rb1, Rc, and Rb2) are altered, and less-polar ginsenosides are generated (e.g., Rg3, Rg5, Rk1, and Rh4). The aim of this study was to determine the effect of FBG on wound healing. Methods: The effects of FBG on tube formation and on scratch wound healing were measured using human umbilical vein endothelial cells (HUVECs) and HaCaT cells, respectively. Protein phosphorylation of mitogen-activated protein kinase was evaluated via Western blotting. Finally, the wound-healing effects of FBG were assessed using an experimental cutaneous wounds model in mice. Results and Conclusion: The results showed that FBG enhanced the tube formation in HUVECs and migration in HaCaT cells. Western blot analysis revealed that FBG stimulated the phosphorylation of p38 and extracellular signal-regulated kinase in HaCaT cells. Moreover, mice treated with $25{\mu}g/mL$ of FBG exhibited faster wound closure than the control mice did in the experimental cutaneous wounds model in mice.

• Bulletin of the Korean Chemical Society
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• v.9 no.6
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• pp.368-376
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• 1988

Transition metal PSSA ionomers containing Co(II), Ni(II), Cr(III), Ru(III), and Rh(III) are investigated by IR, Far-IR, UV-Vis and DSC. Reliable IR Spectroscopic criteria are established for assessing the degree of ion-exchange of PSSA ionomers and the local structures around metal cations in them. In the hydrated transition metal PSSA ionomers, the ionic groups are solvated by water molecules and there is no significant interactions between sulfonate group and metal cations. The visible spectra indicated that metal cations are present as [M$(H_2O)_6$]$^{n+}$ with Oh symmetry. Their $T_g$ values increase as the extent of ionic site concentration increases, but there is no direct dependence of $T_g$ on the nature of metal cations or their oxidation states. Thus, the water content in PSSA ionomer is found to have dominant influence on $T_g$ of hydrated transition metal PSSA ionomers. Dehydration of the hydrated transition metal PSSA ionomers results in direct interaction between ionic groups and significant color changes of the ionomers due to the changes of the local structures around metal cations. On the base of spectral data, their local structures are discussed. In case of dehydrated 12.8 and 15.8 mol % transition metal PSSA ionomers, no glass transition is observed in 25-$250^{\circ}C$ region and this is believed to arise from the formation of highly crosslinked structures caused by direct coordination of sulfonate groups of metal cations. In the 6.9 mol % transition metal PSSA ionomers, the glass transition is always observed whether they are hydrated or dehydrated and this is though to be caused by the sufficient segmental mobility of the polymer backbone.

• Horticultural Science & Technology
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• v.17 no.4
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• pp.467-469
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• 1999

This study was conducted to examine the changes of nutritive substances in the edible potato varieties ('Superior', 'Atlantic', 'Irish Cobbler', 'Dejima') during storage under low temperature condition($4^{\circ}C$, 85-90% RH) from January to May. The items examined in this experiment were moisture, free soluble sugars, starch and vitamin C. The contents of starch and vitamin C decreased with increasing storage period. The rates of decrease in starch and vitamin C contents were high in February and low after that. The contents of moisture and free soluble sugars did not show a constant tendency during storage period. The contents of glucose and fructose were the highest in February and March. Among the four varieties, 'Superior' contained highest vitamin C, free sugar, and moisture, while 'Atlantic' contained the highest starch.

• KSBB Journal
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• v.28 no.5
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• pp.319-326
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• 2013

This study was carried out to investigate the in vitro and in vivo moisturizing properties and percutaneous absorption of PEG-impregnated Aloe vera gel. The PEG-i-Aloe gel was obtained from dewatering and impregnation by soaking (DIS) of Aloe vera leaf slice. The moisturizing property of the obtained sample was evaluated by moisture determination using gravimetric method in desiccator under different RH% and by water sorption-desorption test on human skin. The transdermal penetration characteristics of PEG-i-Aloe gel was investigated by Franz diffusion cell in vitro transdermal absorption method. PEG-i-Aloe gel had high moisture retention ability and could significantly lead the enhancing skin hydration status as well as reducing the skin water loss due to the film formation as a skin barrier. The skin penetration rate of PEGi- Aloe gel at steady state was 9.76 ${\mu}g/(h{\cdot}cm^2)$ and the quantity of the transdermal absorption was 144 ${\mu}g/cm^2$ in 9 hr. The penetration mechanism was well fitted with Higuchi model ($R^2$ = 0.974-0.994). The results show that PEG-i-Aloe gel has the significant moisturizing effect and strong penetration of the animal skin. It could be used as the moisturizing additive in cosmetic skin products.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.505-512
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• 2017

Toxoplasma gondii cathepsin C proteases (TgCPC1, 2, and 3) are important for the growth and survival of T. gondii. In the present study, B-cell and T-cell epitopes of TgCPC1 were predicted using DNAstar and the Immune Epitope Database. A TgCPC1 DNA vaccine was constructed, and its ability to induce protective immune responses against toxoplasmosis in BALB/c mice was evaluated in the presence or absence of the adjuvant ${\alpha}-GalCer$. As results, TgCPC1 DNA vaccine with or without adjuvant ${\alpha}-GalCer$ showed higher levels of IgG and IgG2a in the serum, as well as IL-2 and $IFN-{\gamma}$ in the spleen compared to controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). Upon challenge infection with tachyzoites of T. gondii (RH), $pCPC1/{\alpha}-GalCer$ immunized mice showed the longest survival among all the groups. Mice vaccinated with DNA vaccine without adjuvant (pCPC1) showed better protective immunity compared to other controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). These results indicate that a DNA vaccine encoding TgCPC1 is a potential vaccine candidate against toxoplasmosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.1
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• pp.1-11
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• 2012

Purpose: The purpose of this study was to evaluate the bone regeneration capacity of silk fibroin (SF) when combined with beta tricalcium phosphate (${\beta}$-tricalcium phosphate [TCP]) and rh-bone morphogenetic protein (BMP) in vivo by micro-computed tomography (CT), soft x-ray, and histological analysis. Methods: A total of 56 critical size defects formed by a trephine bur made on 28 adult female Spague-Dawley rats were used for this study and the defect size was 5.0 mm in diameter. The defects were transplanted with (1) no graft material (raw defect), (2) autogenous bone, (3) SF ($10{\mu}g$), (4) SF-BMP ($10{\mu}g$, $0.8{\mu}g$ each), and (5) SF+${\beta}$-TCP ($10{\mu}g$). At 4 and 8 weeks after operation, the experimental animals were sacrificed. Samples were evaluated with soft x-ray, histological examinations and 3-dimensional micro-CT analysis. Results: In the 3-dimensional micro-CT evaluation, bone volume and bone surface data were higher in the SF-BMP ($12.8{\pm}1.5$, $138.6{\pm}45.0$ each) (P<0.05) and SF-TCP ($12.3{\pm}1.5$, $144.9{\pm}30.9$ each) group than in the SF group ($6.1{\pm}3.3$, $77.2{\pm}37.3$ each) (P<0.05), except for the autogenous group ($15.0{\pm}3.0$, $190.7{\pm}41.4$ each) at 4 weeks. At 8 weeks, SF-BMP ($16.8{\pm}3.5$, $173.9{\pm}34.2$ each) still revealed higher (P<0.05) bone volum and surface, but SF-TCP ($11.3{\pm}1.5$, $1132.9{\pm}52.1$ each) (P=0.5, P=0.2) revealed the same or lower amount compared with the SF group ($13.8{\pm}2.7$, $127.5{\pm}44.8$ each). The % of bone area determined by radiodensity was higher in the SF-TCP ($31.4{\pm}9.1%$) and SF-BMP ($36.2{\pm}16.2%$) groups than in the SF ($19.0{\pm}10.4$) group at the period of 4 weeks. Also, in the histological evaluation, the SF-BMP group revealed lower inflammation reaction, lower foreign body reaction and higher bone healing than the SF group at postoperative 4 weeks and 8 weeks. The SF-TCP group revealed lower inflammation at 4 weeks, but accordingly, as the TCP membrane was absorbed, inflammatory and foreign body reaction are increased at 8 weeks. Conclusion: The current study provides evidence that the silk fibrin can be used as an effective grafted material for tissue engineering bone generation through a combination of growth factor or surface treatment.

• Journal of Pharmaceutical Investigation
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• v.25 no.3
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• pp.227-237
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• 1995

Omeprazole(OMP) complexes such as inclusion complexes of OMP with $hydroxypropyl-{\beta}-cyclodextrin$(HPCD) and ${\beta}-cyclodextrin({\beta}-CD)$, OMP-cholestyramine(CHL) and OMP-ethylenediamine(OMP-ED) were prepared, respectively. The partition coefficients in Witepsol H-15 /pH 7.4 phosphate buffer solution of OMP complexes$(OMP-HPCD;\;3.69{\pm}0.26,\;OMP-{\beta}-CD;\;4.08{\pm}0.21,\;OMP-CHL;\;4.36{\pm}0.25\;and\;omeprazole\;sodium(OMP-Na);\;3.64{\pm}0.37)$ were higher than that of OMP $(2.66{\pm}0.47)$. OMP was not completely dissolved until even 3 hrs, but all the OMP complexes studied were released about 100% in 20 min. The rectal suppositories containing OMP or each above OMP complex were prepared using Witepsol H-15 base, and their dissolution and stability were examined, and pharmacokinetic study were investigated after their rectal administrations to the rabbits. While the suppository containing OMP was released only less than 60% in 150 min, $OMP-{\beta}-CD$, OMP-CHL, OMP-Na and OMP-ED suppositories were all released about 65% in 20 min. Especially, OMP-HPCD suppository released OMP about 70% in 10 min. All the additives such as sodium laurylsulfate, eglumine, arginine and PVP increased drug release from OMP-HPCD suppository to some extent. The decomposition rate constants of OMP in the suppositories were $9.117{\times}10^{-3}\;day^{-l}$ for OMP suppository, $2.121{\times}10^{-2}$ for OMP-HPCD, $1.607{\times}10^{-2}$ for $OMP-{\beta}-CD$, $9.26{\times}10^{-3}$ for OMP-Na, $6.769{\times}10^{-3}$ for OMP-CHL and $5.58{\times}10^{-3}\;day^{-l}$ for OMP-ED suppository, respectively. Additives such as arginine, eglumine and ED had some stabilizing effect for OMP-HPCD, OMP-CHL and OMP-Na suppositories, respectively. After 6 month-storage at $30^{\circ}C$, 75% RH, OMP-CHL suppository was most stable. The values of Tmax for OMP-HPCD and OMP-Na suppositories were $11.7{\pm}2.36\;and\;11.4{\pm}2.56\;min$, respectively. The values of Cmax for OMP-HPCD and OMP-CHL suppository were $2.31\;{\mu}g/ml\;(p<0.01)\;and\;1.89\;{\mu}g/ml\;p<0.01)$, respectively. The values of AUC for OMP and $OMP-{\beta}-CD$ suppository were $61.9{\pm}25.79\;and\;68.6{\pm}29.48\;{\mu}g\;{\cdot}\;min/ml$, and the corresponding values for OMP-HPCD and OMP-CHL were $106.1{\pm}43.16\;(p<0.05)\;and\;127.3{\pm}42.52\;{\mu}g\;{\cdot}\;min/ml(p<0.01)$, respectively. The above results indicate the OMP-HPCD and OMP-CHL suppositories have the excellent bioavailabilties in vivo study.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.443-448
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• 2008

In this study, black garlic was produced by aging under high temperature $(70^{\circ}C)$ and high humidity (90% RH) conditions. Then, the physiological activity and antioxidative effects of its extract were compared to those of normal garlic extract. The black garlic extract had a 2.5-fold higher total polyphenol content than that of the normal garlic extract, showing levels of 10.0 mg/g and 3.7 mg/g, respectively. At the $1,000{\mu}g/mL$ concentration, the black garlic and normal garlic extracts had electron donating abilities of 101.9% and 12.9%, respectively. For their nitritescavenging effects, the normal garlic extract showed slightly higher scavenging activity than the black garlic extract at the 5 mg/mL concentration; whereas the black garlic extract had a slightly higher effect at concentrations above 20 mg/mL. In terms of their superoxide dismutase activities, the black garlic extract showed a 10-fold higher activity as compared to the normal garlic extract at the 20 mg/mL concentration. Furthermore, at 50 mg/mL, the angiotensin converting enzyme inhibitory effects of the normal garlic and black garlic extracts were approximately 52.7% and 88.8%, respectively. These results indicate that the antioxidant activity and ACE inhibitory effects of the black garlic extract were greater than those of the normal garlic extract.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.55-59
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• 2000

A specific and sensitive sandwich enzyme-immunoassay (EIA) using Avidin-Biotin complex was developed for the measurement of GTH II levels in pituitary content and pituitary cell culture medium of the rainbow trout-(Oncorhpchus mykiss). Biotin-salmon GTH II rabbit IgG (sefondary antibody) wai purified by a protein A sepharose affinity chromatography column and that was biotinylated by using Biotin-N-hydroxysuccinimide ofter (BNHS). Non-biotin salmon GTH II rabbit IgG (first antibody) was obtained only through a protein A sepharose affinity chromatography column. The assay was performed by the so-called 'sandwich' method using a microtiter plate, A dose-response curve was obtained between $0.12 to 125 ng/ml$ of salmon GTH II. The displacement curves for pituitary extraction and pituitary cell culture medium of testosterone-treated rainbow trout were Parallel to the standard curie. The intra-assay and inter-assay coefficients of variation (CV) were $8.2{\%} (N=5) and 12.5{\%} (N=6)$, respectively, This assay system was used to measure the amount of GTH II that accumulated in the culture medium of dispersed pituitary cells in testosterone-treated immature rainbow trout, The accumulation was increased with the amount or salmon gonadotropin-releasing hormone. GTH II values determined by the present method were well correlated with those determined by radioimmunoassay. As a result, this assay system was found to be suitable for the measurement of GTH II for pituitary extraction and pituitary culture medium in many salmonid fishes.