• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.201-214
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• 1983

A study was undertaken on rats in order to clarify the gastric mucosal, morphologic response to oral and subcutaneous administration of acetylsalicylic acid(aspirin). Aspirin was administered orally (oral group) and subcutaneously (subcutaneous group) at does rate of 60 mg per kg of body weight per day to 40 normal rats. On the 1st, 3rd, 7th, and 15th day of administration, in addition to clinical observation, 5 rats each from the both groups were sacrificed and examined macroscopically, histologically and electron-microscopically for the morphological changes of gastric mucosal cells with the following results. Although the clinical, macroscopic and histological changes were not significant, marked ultrastructural changes were observed. Parietal and chief cells were affected most severely by the administration of aspirin ; parietal cells showed increase in the number of SER and intracellular canaliculi, where-as in chief cells fragmentation, luminal dilatation, decrease in the number and structural abnormalities of RER were seen. Relatively mild changes were observed in mucous, mucous neck and basal-granulated cells. Although the degree of changes was milder than those of oral group, the similar changes were also observed in the subcutaneous group. From these results, it would be concluded that aspirin injury of gastric mucosa is effected not only by the direct injury to the mucosa but also indirectly by the blood concentration of aspirin.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.386-386
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• 2012

For white light emitting diode (LED) applications, it has been reported that Y3Al5O12:Ce3+ (YAG:Ce) in nano-sized phosphor performs better than it does in micro-sized particles. This is because nano-sized YAG:Ce can reduce internal light scattering when coated onto a blue LED surface. Recently, there have been many reports on the synthesis of nano-sized YAG particles using bottom-up method, such as co-precipitation method, sol-gel process, hydrothermal method, solvothermal method, and glycothermal method. However, there has been no report using top-down method. Top-down method has advantages than bottom-up method, such as large scale production and easy control of doping concentration and particle size. Therefore, in this study, nano-sized YAG:Ce phosphors were synthesized by a high energy beads milling process with varying beads size, milling time and milling steps. The beads milling process was performed by Laboratory Mill MINICER with ZrO2 beads. The phase identity and morphology of nano-sized YAG:Ce were characterized by X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (FESEM), respectively. By controlling beads size, milling time and milling steps, we synthesized a size-tunable and uniform nano-sized YAG:Ce phosphors which average diameters were 100, 85 and 40 nm, respectively. After milling, there was no impurity and all of the peaks were in good agreement with YAG (JCPDS No. 33-0040). Luminescence and quantum efficiency (QE) of nano-sized YAG:Ce phosphors were measured by fluorescence spectrometer and QE measuring instrument, respectively. The synthesized YAG:Ce absorbed light efficiently in the visible region of 400-500 nm, and showed single broadband emission peaked at 550 nm with 50% of QE. As a result, by considering above results, high energy beads milling process could be a facile and reproducible synthesis method for nano-sized YAG:Ce phosphors.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.668-681
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• 2020

The purpose of this study was aimed to isolate a Salmonella Typhimurium-specific phage (KFS-ST) from washing water in a poultry processing facility and to investigate the feasibility of the KFS-ST as a novel bio-receptor for the magnetoelastic (ME) biosensor method. KFS-ST against S. Typhimurium was isolated, propagated, and purified using a CsCl-gradient ultracentrifugation. Morphological characteristics of KFS-ST were analyzed using transmission electron microscopy (TEM). Its specificity and efficiency of plating analysis were conducted against 39 foodborne pathogens. The temperature and pH stabilities of KFS-ST were investigated by the exposure of the phage to various temperatures (-70℃-70℃) and pHs (1-12) for 1 h. A one-step growth curve analysis was performed to determine the eclipse time, latent time and burst size of phage. The storage stability of KFS-ST was studied by exposing KFS-ST to various storage temperatures (-70℃, -20℃, 4℃, and 22℃) for 12 weeks. KFS-ST was isolated and purified with a high concentration of (11.47 ± 0.25) Log PFU/mL. It had an icosahedral head (56.91 ± 2.90 nm) and a non-contractile tail (225.49 ± 2.67 nm), which was classified into the family of Siphoviridae in the order of Caudovirales. KFS-ST exhibited an excellent specificity against only S. Typhimurium and S. Enteritidis, which are considered two of the most problematic Salmonella strains in the meat and poultry. However, KFS-ST did not exhibit any specificity against six other Salmonella and 27 non-Salmonella strains. KFS-ST was stable at temperature of 4℃ to 50℃ and at pH of 4 to 12. The eclipse time, latent time, and burst size of KFS-ST were determined to be 10 min, 25 min and 26 PFU/ infected cell, respectively. KFS-ST was relatively stable during the 12-week storage period at all tested temperatures. Therefore, this study demonstrated the feasibility of KFS-ST as a novel bio-receptor for the detection of S. Typhimurium and S. Enteritidis in meat and poultry products using the ME biosensor method.

• Journal of Life Science
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• v.30 no.9
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• pp.783-790
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• 2020

The present study investigates the antioxidant and anti-inflammatory activities of Mangifera indica L. leaf extract. The total polyphenol content was measured using the Folin-Denis method. Results showed that the M. indica L. leaf extract of water and 70% ethanol showed a content of 440.83±1.02, 475.63±1.3 mg/100 g tannic acid equivalent. To assess antioxidant activity and electron-donating ability, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity were measured, and all extracts were found to be highly efficacious. To assess cell viability of the extract from M. indica L. leaf on macrophage cells (RAW 264.7), a 3-[4,5-dimethyl-thiazol-2- yl]-2,5-diphenyl-tetrazolium-bromide assay was performed. The following experiments were conducted in section where cells was not shown of toxicity. In order to effectively determine anti-inflammatory activity, inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells was examined using a Griess assay. The result showed that M. indica L. leaf extract concentration-dependently inhibited NO production. M. indica L. leaf extract was measured using Western blot, reverse transcription- polymerase chain reaction (RT-PCR) that to find the production of pro-inflammatory factor on stimulated RAW 264.7 cells of LPS. According to the results of this study, the M. indica L. leaf extract showed excellent effectiveness in antioxidant and anti-inflammatory activity, thus confirming its usability as a natural material and a functional raw material for cosmetics.

• Journal of dental hygiene science
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• v.8 no.2
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• pp.89-96
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• 2008

Effects of sodium fluoride exposure on the amelogenesis during fetal formation were investigated using 11 days rat incisor of control group and two experimental groups. According to results of morphological analysis using an electron microscope, enamel organ in the rat incisor consisted of presecretory, secretory, and maturation zone, especially maturation zone had ruffle-ended ameloblasts (rAB) that additionally supply inorganic ions and smooth-ended ameloblasts (sAB) that remove water and organic compounds. Such a histological composition was same in fetal and adult rats. According to experimental results using calcein (green fluorescence) in order to reveal the modulation cycle of ameloblast, modulation cycle of experimental group decreased on an average one time than control group, as increase of density of sodium fluoride indicated that thickness of smooth-ended ameloblast decreased. Also ratio of thickness on sagittal total length of sAB increased than rAB in experimental groups than control group. In total length of teeth, an injected 100 ppm sodium fluoride group was similar control group but as injected 200 ppm group became short. In experimental group, thickness of sAB and rAB became narrow to the tip of cutting edge. According to concentration of sodium fluoride grows, the modulation cycle and total length of teeth were decreased, finally it prevented teeth growth.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.50-57
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• 2017

Zinc oxide is, one of metal oxide semiconductor, harmless to human and environment-friendly. It has excellent chemical and thermal stability properties. Wurtzite-zinc oxide is a large band gap energy of 3.37 eV and high exciton binding energy of 60 meV. It can be applied to various fields, such as solar cells, degradation of the dye waste, the gas sensor. The photocatalytic activity of zinc oxide is varied according to the particle shape and change of crystallinity. Therefore, It is very important to specify the additives and the experimental variables. In this study, the zinc oxide were synthesized by using a microwave assisted hydrothermal synthesis. The precursor was used as the zinc nitrate, the pH value was controlled as 11 by NaOH. Surfactants are the ethanolamine, cetyltrimethylammonium bromide, sodium dodecyl sulfate, sorbitan monooleate was added by changing the concentration. The composite particles had the shape of a star-like, curcular cone, seed shape, flake-sphere. Physical and chemical properties of the obtained zinc oxide was characterized using x-ray diffractometer, field emission scanning electron microscopy, thermogravimetric analysis and optical properties was characterized using UV-visible spectroscopy, photoluminescence and raman spectroscopy.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.215-225
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• 2015

Recently, the importance of energy saving and alternative energy is significantly increasing due to energy depletion and the phase change material (PCM) research for saving energy is also actively investigating. In this research, the membrane emulsification using SPG membrane was used to make various microencapsulated phase change material (MPCM) particles which were comprised of $Rubitherms^{(R)}$ (RT-21 and RT-24) core and silica coating. We investigated the pressure of the dispersion phase, the concentration of surfactant, and the ratio of $Rubitherm^{(R)}$ and silica to prepare various MPCM particles. The DSC and TGA were used to examine the heat stability and latent heat properties. Also, PSA, SEM, and optical microscopy were used to confirm the size of $Rubitherm^{(R)}$ particles and the thickness of silica shell. The average of particle size was $7-8{\mu}m$. And, FT-IR was also used to enforce the qualitative analysis. Finally, the MPCM particles obtained from membrane emulsification showed monodispersed size distribution and the heat stability and latent heat were kept up to 80% compared to pure $Rubitherm^{(R)}$. So, it can be effectively used for wallpaper, buildings and interior products for energy saving as PCMs.

• Journal of the Korean Chemical Society
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• v.61 no.4
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• pp.179-184
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• 2017

In this paper, a $ZnO/SiO_2$ nano-composite was prepared by a simple chemical method at room temperature. For the synthesis of ZnO nanoparticles (NPs), a sonochemical method was used, and $SiO_2$ NPs were prepared by precipitation method. The formation of $ZnO/SiO_2$ NCs was characterized by X-ray diffractometer (XRD) and confirmed by field-emission scanning electron microscopy (FE-SEM) and Fourier transform infra-red spectroscopy(FT-IR). The photocatalytic properties of $ZnO/SiO_2$ NCs formed at different concentrations of $SiO_2$ were evaluated by rhodamine-B dye. It was confirmed that increasing $SiO_2$ concentration resulted in an increase in the photocatalytic property. In addition, the antibacterial activity of $ZnO/SiO_2$ NCs was conducted against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). As a result, the antibacterial activities of E.coli and S. aureus were increased in the presence of thick SiO NPs layer.

• Journal of Food Hygiene and Safety
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• v.20 no.1
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• pp.53-57
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• 2005

This study was performed to observe the components, antioxidative, antimutagenic and cytotoxic effects of the mineral water using AOAC method, DPPH free radical donating method, Ames test and SRB assay. Mineral water contained eleven kinds of minerals among the total seventeen components and sodium and potassium ion were main components. Mineral water showed electron donating activities ($175.9{\mu}g$). The inhibition rate of mineral water ($200{\mu}g/plate$) in the Sallmonella typhimurium TA98 strain showed $54\%$ against the mutagenesis induced by Trp-P-1. In addition, same concentration of mineral water the Sallmonella typhimurium TA100 strain showed highest $67\%,\;65.8\%\;and\;63\%$ inhibition against $B({\alpha})P$, 4NQO and Trp-P-1, respectively. The cytotoxic effects of mineral water against the cell lines with Human lung carcinoma (A549), Human breast adenocarcinoma (MCF-7), Human stomach adenocarcinoma (AGS) and Human cervical adenocarcinoma (Hela) were inhibited with the increase of the mineral water. The treatment of $50{\mu}g/well$ of mineral water showed cytotoxicities of $66\%,\;47.6\%,\;37.7\%\;and\;45.6\%$ against A549, MCF-7, AGS and Hela.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1358-1364
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• 2007

Response surface methodology was employed to investigate the change of flavonoids components of citrus peel hydrolysate using Viscozyme L as the enzyme. As citrus peels were hydrolyzed by the enzyme, hesperetin and naringenin contents of flavonoids aglycone form increased. The optimal enzyme treatment conditions which were superimposed of the maximized levels for soluble solid, hesperetin, and naringenin contents were enzyme concentration of 1.5% and reaction time of 18 hr. In enzyme-untreated citrus peels (CC), soluble solid content was 48.49% and the content of hesperidin only detected flavonoids was 58.85 mg/g. In the case of optimal enzyme-treated citrus peels (CE), soluble solid content was 72.97% and the contents of naringin, hesperidin, naringenin and hesperetin were 1.56 mg/g, 31.31 mg/g, 2.58 mg/g and 3.90 mg/g, respectively. In the results of electron donating ability and angiotensin converting enzyme inhibition activity, the activity of CE was higher than that of CC.