• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.389-397
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• 2019

Lysosomes are cellular organelles involved in energy metabolism and intracellular digestion in eukaryotic cells, including protease, nuclease, glycosidase, lipase, and phosphatase. Our previous studies have confirmed that egg white lysosomes had melanin decolorization and reduction activity. However, there have been few studies on skin barrier and skin regeneration as well as inhibition of melanin production by egg white lysosomes on B16F10 melanocyte cell line. In this study, we attempted to identify the effect of lysosome-related organelle extract (LOE) extracted from egg white on the melanin content change and skin barrier enhancement in cells. First, cytotoxicity evaluation was performed on B16F10 melanocyte cell line to confirm the whitening efficacy of LOE. Cytotoxicity by LOE was not observed at 20 mg/mL concentration, but cytotoxicity was observed at 40 mg/mL, and the maximum concentration value was set to 20 mg/mL in all subsequent experiments. LOE samples of 5, 10, 20 mg/mL inhibited melanin production by 61.5 ± 4.0%, 61.4 ± 7.3%, 58.3 ± 8.3%, respectivly, compared to α-MSH, a negative control in melanin contents assay. MITF mRNA expression was reduced by about 39.7 ± 3.2% compared to the α-MSH treatment group. TEER assay using HaCaT showed that LOE increased TEER resistance in a dose-dependent manner, indicating that LOE is involved in strengthening the skin barrier. LOE also increased the TEER resistance under TNF-α treatment. Skin barrier was normally restored by LOE even under the condition of inflammation. LOE had a positive effect on cell division and cell migration promotion, confirmed by the observing the effect of promoting cell migration by LOE through cell migration assay. Taken together, we expect that LOE can be developed as a cosmetic material to enhance has effects on skin regeneration and skin barrier strengthening as well as whitening function if enzyme stabilization and formulation technology are combined.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.317-328
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• 2019

In this work, we investigated clay and raw materials from China (black clay, red clay, white clay) and Korea (Cheonan clay, Obu clay) used for the manufacture of porcelain products. According to chemical analysis results, feldspar components containing CaO, K₂O, Na₂O and quartz are found in clay materials besides primary clay such as kaollinte, for the clay materials from Korea, which is found more in clay materials from Korea than from China. For the Fe₂O₃ content, governing whiteness of porcelain products, more iron oxide (> 5 %) is found in Korean clays (Cheonan clay, obu clay, red clay) compared to those form China (black, white clay). Through X-ray diffraction analysis, kaolinite and Halloysite are found to be main phases for all the raw materials and second phases such as quartz and pyrophyllite are found. Using these clay materials, raw materials for porcelain products were produced, and the physicochemical properties were investigated for sintered samples. Absorption rate is in order of Baekja-A < Baekja-B < Yeonbuncheong < Jinbuncheong < Cheongja, and the sample, sintered at 1250℃ in reductive atmosphere, exhibits the lowest absorption rate. Comparing the color of the sintered samples, the samples sintered in oxidative atmosphere (L^* value: 86~95 %) show higher whiteness value than those sintered in reductive atmosphere (L^* value: 81~93 %). For the Cheongja and Buncheong, the samples sintered in reductive atmosphre shows higher whiteness, L^* values, and low a^*/b^* value, which is due to reduction of iron oxide (Fe₂O₃).

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.135-142
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• 2010

Purpose: This study was aimed to compare the margin and internal fitness of single anterior all-ceramic crown zirconia core made by three deferent CAD/CAM systems. Material and methods: Five single zirconia cores were manufactured by three deferent CAD/CAM systems($Cerasys^{(R)}$system, KaVo $Everest^{(R)}$system, $LAVA^{TM}$system). The manufactured zirconia cores were duplicated through the use of replica technique, and a replicated sample was sectioned in the center of bucolingual and mesiodistal direction to measure the marginal and internal gap. Measurement was carried out by using measuring microscope ($AXIO^{(R)}$) and $I-Solution^{(R)}$ and analysed through the use of ANOVA. Results: As for the mean marginal fitness of the zirconia core, it was $84.74{\pm}27.57{\mu}m$, in $Cerasys^{(R)}$, $80.23{\pm}21.07{\mu}m$ in KaVo $Everest^{(R)}$ and $96.37 {\pm}11.45{\mu}m$ in $LAVA^{TM}$, and as for the mean internal gap, it was $94.11{\pm}30.07{\mu}m$ in $Cerasys^{(R)}$, $92.31{\pm}25.18{\mu}m$ in KaVo $Everest^{(R)}$, and $94.99{\pm}18.74 {\mu}m$ in $LAVA^{TM}$. There was no significant statistically deference among the total average gap of three systems. The internal gap in KaVo $Everest^{(R)}$ seemed to be smaller than $LAVA^{TM}$ (P < .05). The internal gap in the incisal area was larger in all of the three systems. Conclusion: There was no difference in marginal fitness in $Cerasys^{(R)}$, KaVo $Everest^{(R)}$ and $LAVA^{TM}$. As for the internal fitness, it was smaller in KaVo $Everest^{(R)}$ system than $LAVA^{TM}$ system. In all of the three systems, there was a larger gap in incisal area. The marginal and internal gap was within the clinically allowed range in all of the three systems.

• The korean journal of orthodontics
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• v.41 no.6
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• pp.399-410
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• 2011

Objective: The purpose of this study was to evaluate the difference in frictional resistance among metal, ceramic, self-ligation brackets and coated or non-coated Ni-Ti archwires at various bracket-archwire angulations during the sliding movement of an orthodontic archwire, using an orthodontic sliding simulation device. Methods: Four types of bracket (Micro-arch Perpect Clear2 Clippy-C and Damon3 and 5 types of orthodontic archwire (0.014", 0.016", and 0.016" ${\times}$ 0.022" inch coated Ni-Ti, and 0.016" and 0.016" ${\times}$ 0.022" inch Ni-Ti) were used. Further, the bracket- archwire angles were set at 4 different angulations: $0^{\circ}$, $3^{\circ}$, $6^{\circ}$, and $9^{\circ}$. Results: The frictions from all the experimental groups were found to be significantly increased in order of self-ligation brackets, Micro-arch and Perpect Clear2 ($p$ < 0.001). The presence of a coat had no effect on the friction of the same sized archwires at $0^{\circ}$ and $3^{\circ}$ bracket-archwire angles ($p$ < 0.001). Coated archwires had significantly higher frictions than the same sized non-coated archwires at $6^{\circ}$ and $9^{\circ}$ bracket-archwire angles ($p$ < 0.001). The frictions increased significantly as the bracket-archwire angles were increased ($p$ < 0.001). Conclusions: The use of self-ligation brackets will be beneficial in clinical situations where a low frictional force is required. Further, in cases where crowding is not severe, the use of coated archwires should not cause problems. However, more additional explanation is required considering the fact that the damage of coated archwire and exposure of the metal portion in case of binding and notching and the effects of saliva were not taken into account.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2000.04a
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• pp.9-10
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• 2000

An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.286-292
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• 2008

This study was conducted to analyze and determine the formation potential of chlorination DBPs from seven urinary compounds with or without Br$^-$. Three of seven components were kynurenine, indole and uracil that were relatively shown high the formation potential of chlorination DBPs concentrations. The reported results of THMs/DOC with or without Br$^-$ in kynurenine showed that THMs/DOC was detected 86.9 $\mu$g/mg when Br$^-$ was not added, and THMs/DOC was detected 100.8 $\mu$g/mg when Br$^-$ was presented. In indole, THMs/DOC was increased from 6.58 $\mu$g/mg to 31.4 $\mu$g/mg when Br$^-$ was added. Moreover, among them, the highest, second-highest and third-highest HAAs/DOC were shown in kynurenine, uracil and indole respectively. Specially, HAAs/DOC was significantly deceased in kynurenine and indole when Br$^-$ was presented. This was a totally different phenomenon for THMs/DOC. TCAA was dominated in HAAs for kynurenine and indole, and DCAA was also dominated in HAAs for uracil. The highest formation of HANs/DOC was shown in kynurenine whether or not Br$^-$ presented, and DCAN was predominant in HANs. HANs was not formed by chlorination in uracil. In addition, the formation of CH/DOC was relatively low in kynurenine and indole. The formation of CH/DOC was specially high(1,270 $\mu$g/mg) in uracil when Br$^-$ was not added. The formation of CH/DOC was 1,027 $\mu$g/mg in uracil when Br$^-$ was added. The formations of THMs and HAAs were also investigated in kynurenine, indole and uracil when Br$^-$ was presented or not. The formation of THMs/DOC was higher in kynurenine and indole when Br$^-$ was presented. The formation of HAAs/DOC was reduced in kynurenine when Br$^-$ was added. The result could be attributed to higher formation of THMs/DOC in kynurenine when Br$^-$ was added. The formation of HAAs/DOC was also reduced in indole when Br$^-$ was added. To the contrary, this result was not attributed to higher formation of THMs/DOC in indole when Br$^-$ was added.

• Journal of Science of Art and Design
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• v.9
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• pp.5-24
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• 2006

Human hunted and picked to survive and a vessel was made naturally to store something being hunted and picket, which was a great invention. In modern times, society changed and development of science gave us convenience in making a vessel and various kinds of store instruments which was made of pure natural material, of new stuff, such as plastic and iron. but human became to be inclined to regress into nature because of problems of environment. We can say that the representative trend is well-being, after all this is a symptom to return to life being persued by predecessors before the science civilization was developed. Ancestors have lived with nature, adapted themselves to it. For examples they have built the house which became to be a part of nature and just like it, and studied a method of storing food to eat for four seasons, then displayed a storagehouse and storage containers everywhere of the house. Now Korean has the custody of kimchi in refrigerator at every house, but our forefathers controled a timing to eat food with studying a method of storage to put to use nature. With hot wind of well-being, Korean food is becoming to be globalized, according to this, concern about the wisdom of progenitors is growing more and more. It's an example that the world shows concern seriously about the pottery, which have stored kimchi for a long time fleshly, in globalization of kimchi. This study have three purposes, the first. checking documents about the development history of pottery which is a kind of ceramic, and then the second, through an scientific experiment, with studying characteristic of pottery being built by the wisdom of ancestors, informing the merit of pottery and necessity to the world, and futhermore, the third, working up the development of close environmental vessels putting to use the characteristic of pottery.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1079-1085
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• 2003

Modified atmosphere packaging was applied to oyster mushrooms (Pleurotus ostreatus) to study the effect of storage temperatures and packaging materialso. Whole mushrooms (200g) were package with polyethylene film $(PE,\;60{\mu}m\;thickness)$, ethylene vinyl acetate (EVA), or ceramic film (containing 5% zeolite) and stored at 0, 5, 10 and $20^{\circ}C$. Weight loss, color, firmness, gas composition $(O_2,\;CO_2)$ inside the film package and ethanol content in the tissue of MA packaged mushrooms were examined. Mushroom that were packed unwrapped in a conventional hardboard box (2 kg) lost marketability at a very early stage of storage due to weight loss, shrinkage, browning, and spore formation. During storage, film packaging prevented or retarded the deterioration of the mushrooms in the aspects of appearance, texture, and discoloration. Firmness slightly decreased with storage time. Total color difference was much higher in the control than in the film-packaged mushroom and rapidly increased at the early of storage. Correlation analysis showed a high correlation between total color difference and b values. These results were characterized by the reduced respiration rate resulting from elevated carbon dioxide and reduced oxygen levels in the package. At all storage temperatures, ethanol content in the tissue increased slightly at the early part of storage and rose considerably towards the end of the storage period. Ethanol content in the oyster mushrooms was higher in the stipe than in pileus tissues. The shelf life of the oyster mushrooms was about $8{\sim}11$ days at $0^{\circ}C$, about $4{\sim}6$ day at $5^{\circ}C$, about $2{\sim}3$ days at $10^{\circ}C$, and about $1{\sim}2$ days at $20^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.196-203
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• 1999

To establish the best rice cultivating system in the aspects of environment-loving agriculture, the amounts and patterns of nitrogen leached in the paddy soil were investigated with 7 treatments; Recommendation(R), Farmer's usual practice(FUP), Straw compost+chemical fertilizers reduced(SCF), Fresh straw+recommendation(FSC), Fresh cow manure(FCM), Cow manure compost(CMC), and no fertilization as Control(C). And SCF, FCM and CMC were applied with same amounts of total nitrogen to R. The infiltrated water samples were collected in ceramic porous cups which were buried at 60cm depth from the top. Concentrations of nitrate-N in irrigated water were $1.3mg\;l^{-1}$ on rice transplanting season when nutrients began to elute from paddy soil, and $0.4mg\;l^{-1}$ after breaking off irrigation. But it was $4-6mg\;l^{-1}$ in rice growing period. The maximum concentration of nitrate-N in leachate was not more than $7mg\;l^{-1}$ during rice cultivation. The amounts of nitrogen leached in R, FUP, SCF, FSR, FCM, CMC and C were 59, 63, 25, 41, 24, 27, $17kg\;ha^{-1}y^{-1}$ respectively. Nitrogen leaching was decreased to about 30% by supplement of fresh rice straw(FSC) to R. Furthermore, it was possible to reduce to over 50% of nitrogen leaching by reducing chemical fertilizer application(CF), or by substituting of chemical fertilizers with fresh cow manure(FCM) or cow manure compost(CMC). In added organic fertilizer treatments, the amounts of infiltrated nitrogen were less $13-46kg\;ha^{-1}y^{-1}$ than that of input by irrigation. This experiment showed that nutrients leaching was minimized by substitution of chemical fertilizers with organic fertilizer or by application of straw with chemical fertilizers in rice paddy soil and rice cultivation with suitable fertilizer management can work as a purifier rather than contaminator of water.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.328-334
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• 2009

Statement of problem: Pier abutments act as a Class I fulcrum lever system when the teeth are incorporated in a fixed partial denture with rigid connectors. Therefore non-rigid connector incorporated into the fixed partial denture might reduce the stresses created by the leverage. Purpose: The purpose of this study was to evaluate, by means of finite element method, the effects of non-rigid connectors and supporting alveolar bone level on stress distribution for fixed partial dentures with pier abutments. Material and methods: A 2-dimensional finite element model simulating a 5-unit metal ceramic fixed partial denture with a pier abutment with rigid or non-rigid designs, the connector was located at the distal region of the second premolar, was developed. In the model, the lower canine, second premolar, and second molar served as abutments. Four types of alveolar bone condition were employed. One was normal bone condition and others were supporting bone reduced 20% height at one abutment. Two different loading conditions, each 150 N on 1st premolar and 1st molar and 300N on 1st molar, were used. Results: Two types of FPD were displaced apically. The amount of displacement decreased in an almost linear slope away from the loaded point. Non-rigid design tended to cause the higher stresses in supporting bone of premolar and molar abutments and the lower stresses in that of canine than rigid design. Alveolar bone loss increased the stresses in supporting bone of corresponding abutment. Conclusion: Careful evaluation of the retentive capacity of retainers and the periodontal condition of abutments may be required for the prosthetic design of fixed partial denture with a pier abutment.