• Toxicological Research
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• v.29 no.1
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• pp.43-52
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• 2013

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

• Journal of the Korean Vacuum Society
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• v.18 no.5
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• pp.358-364
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• 2009

We investigated the growth of ZnO thin films with prominent emission characteristics through minimizing the formation of defects by using pulsed laser deposition (PLD). To do so, the ZnO films were deposited on sapphire(0001) substrates at the substrate temperature of $400-850^{\circ}C$ and then the variation of their structural and optical properties were analyzed by x-ray diffraction, atomic force microscope and photoluminescence. As a result, all ZnO films were grown with c-axis preferential orientation irrespective of the substrate temperature. However, the crystallinity and stress state were dependent on the substrate temperature and the ZnO film deposited at $600^{\circ}C$ showed the best surface morphology and crystallinity with nearly no strain. And also this film exhibited outstanding emission characteristics from the viewpoint of full width half maximum of UV emission peak as well as visible emission due to defects. These results indicate that the emission characteristics of the ZnO films are strongly related to their structural characteristics influenced by substrate temperature. Consequently, ZnO films with strong UV emission and nearly no visible emission, which are applicable to UV emission devices, could be grown at the substrate temperature of $600^{\circ}C$ by PLD.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.557-564
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• 2007

The effect of wave and current interactions on regular wave transformation over a submerged elliptic shoal is investigated based on numerical simulations of the Vincent and Briggs experiment [Vincent, C.L., Briggs, M.J., 1989. Refraction-diffraction of irregular waves over a mound. Journal of Waterway, Port, Coastal and Ocean Engineering, 115(2), pp. 269-284]. The numerical simulations are conducted by constituting two numerical model systems: a combination of SWAN(a wave model) plus SHORECIRC(a current model) and a combination of REF/DIF 1(a wave model) plus SHORECIRC. A time dependent phase-resolving wave-current model, FUNWAVE, is also utilized to simulate the experiment. In the simulations, the breaking-induced currents defocus waves behind the shoal and bring on a wave shadow zone that shows relatively low wave height distributions. The computed results of the two model systems agree better with the measurements than the computed results obtained by neglecting wave-current interaction do. However, it is found that the radiation stresses for standing waves are misevaluated in the wave models. In addition, the results of FUNWAVE show very good agreement with the measurements. The agreement indicates that it is necessary to take into account the effect of breaking-induced current on wave refraction when wave-breaking occurs over a submerged shoal.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.691-700
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• 2008

One suggested mechanism underlying copper (Cu) deficiency teratogenicity is a low availability of nitric oxide (NO), signaling molecule which is essential in developmental processes. Increased superoxide anions secondary to decreased activities of Cu-zinc superoxide dismutase (Cu-Zn SOD) in Cu deficiency can interact with NO to form peroxynitrite, which can nitrate proteins at tyrosine residues. In addition, peroxynitrite formation can limit NO bioavailability. We previously reported low NO availability and increased protein nitration in Cu deficient (Cu-) embryos. In the current study, we tested whether Cu deficiency alters downstream signaling of NO by assessing cyclic GMP (cGMP) and phosphorylated vasodilator-stimulating phosphoprotein (VASP) levels, and whether NO supplementation can affect these targets as well as protein nitration. Gestation day 8.5 embryos from Cu adequate (Cu+) or Cu- dams were collected and cultured in either Cu+ or Cu- media for 48 hr. A subset of embryos was cultured in Cu- media supplemented with a NO donor (DETA/NONOate; 20 ${\mu}M$) and/or Cu-Zn SOD. Cu-/Cu- embryos showed a higher incidence of embryonic and yolk sac abnormalities, low NO availability, blunted dose-response in NO concentrations to increasing doses of acetylcholine, low mRNA expression of endothelial nitric oxide synthase (eNOS), increased levels of 3-nitrotyrosine (3-NT) compared to Cu+/Cu+ controls. cGMP concentrations tended to be low in Cu-/Cu- embryos, and they were significantly lower in Cu-/Cu- yolk sacs than in controls. Levels of phosphorylated VASP at serine 239 (P-VASP) were similar in all groups. NO donor supplementation to the Cu- media ameliorated embryonic and yolk sac abnormalities, and resulted in increased levels of cGMP without altering levels of P-VASP and 3-NT. Taken together, these data support the concept that Cu deficiency limits NO availability and alters NO/cGMP-dependent signaling in Cu- embryos and yolk sacs, which contributes to Cu deficiency-induced abnormal development.

• Proceedings of the KACD Conference
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• 2001.05a
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• pp.235-237
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• 2001

;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

• Journal of the Semiconductor & Display Technology
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• v.6 no.3
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• pp.19-23
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• 2007

The NiSi is very promising candidate for the metallization in 45 nm CMOS process such as FUSI(fully silicided) gate and source/drain contact because it exhibits non-size dependent resistance, low silicon consumption and mid-gap workfunction. Ni film was first deposited by using ALD (atomic layer deposition) technique with Bis-Ni precursor and $H_2$ reactant gas at $220^{\circ}C$ with deposition rate of $1.25\;{\AA}/cycle$. The as-deposited Ni film exhibited a sheet resistance of $5\;{\Omega}/{\square}$. RTP (repaid thermal process) was then performed by varying temperature from $400^{\circ}C$ to $900^{\circ}C$ in $N_2$ ambient for the formation of NiSi. The process temperature window for the formation of low-resistance NiSi was estimated from $600^{\circ}C$ to $800^{\circ}C$ and from $700^{\circ}C$ to $800^{\circ}C$ with and without Ti capping layer. The respective sheet resistance of the films was changed to $2.5\;{\Omega}/{\square}$ and $3\;{\Omega}/{\square}$ after silicidation. This is because Ti capping layer increases reaction between Ni and Si and suppresses the oxidation and impurity incorporation into Ni film during silicidation process. The NiSi films were treated by additional thermal stress in a resistively heated furnace for test of thermal stability, showing that the film heat-treated at $800^{\circ}C$ was more stable than that at $700^{\circ}C$ due to better crystallinity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.227-231
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• 2006

Wrinkle formation is mainly attributed to the environmental factors such as UV rays, air pollution, smoking and stress etc. Especially, UV rays induce premature skin aging which is characterized by deep wrinkle, leathery dryness etc. Recently, researches on the wrinkle formation and its prevention have been the main theme in cosmetics fields. We have studied the various plant extracts having anti-wrinkle effects and finally showed that Noni (Morinda citrifolia) extracts have the efficacy of promoting the type I collagen synthesis in normal human fibroblast, using PICP assay. We purified one active compound from Noni extracts and identified its structure. It was identified as 6,7-Dimethoxy-2H-1-Benzopyran-2-one; scopoletin by $^1H-NMR,\;^{13}C-NMR,$ IR, Mass analysis. Scopoletin increased collagen synthesis in a dose dependent manner (89.5% at $0.2{\mu}g/mL$). In order to verify the anti-aging effectiveness of the cream containing 3% noni extracsts, we performed the in vivo test with some female volunteers for 12 weeks. It reduced the signs of aging, especially face wrinkles. From these results, we conclude that the noni extracts could be used as an useful anti-wrinkle agent.

• Korean Journal of Plant Resources
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• v.31 no.2
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• pp.109-116
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• 2018

Erectile dysfunction (ED), also known as impotence, is the inability to attain and sustain an erection firm enough to have sexual intercourse. Frequent ED may be a symptom of health problems including heart disease, obesity, alcoholism, stress, smoking, and depression, that need treatment. This study aimed to effect of complex extract (CPL) including Cornus officinalis on sexual function factor in the erectile dysfunction rat model. The erectile dysfuction rat model was induced by cimetidine (500 mg/kg in 5% ethanol, oral injection 2 weeks). Rats were oral administered with different concentration of CPL in rat erectile dysfunction model. As a results, sexual function factors (NO, cGMP) significantly improved in CPL treated groups (CPL-300, 600, 900 mg/kg) compared to CON group. Serum testosterone was increased in a dose-dependent manner after CPL treatment. Furthermore, administrations of CPL restored lumen areas of the prostate in the erectile dysfunction rat model. These results indicated that CPL alleviated erectile dysfunction by increasing sexual function factor and testosterone in rat model. CPL could be used to natural treatement for erectile dysfunction. However, further study is required to identify active ingredient and its mechanism of erectile dysfunction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.245-258
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• 2012

ILM(incremental launching method) is a way of construction, installing a girder producing spot behind the abutment, making the bridge girder infilled with concrete continuously and launching with using by jack. The superstructure of the bridge constructed by this method is temporarily located on the center of the span and the supporting points under construction. Therefore, the sections are structurally undergone maximum positive moment, maximum negative moment, and maximum shear force arising from self weight. On the other hand, launching nose is attached to the front of the girder to decrease the cantilever effect. The magnitude of this temporary stress creating on the upper section is dependent upon the launching nose's characteristics. This study has proposed an analysis formula simplified on the assumption that the launching nose section is a quasi-equivalent section(rigid; equivalent section, weight; tapered section) in order to ensure the accuracy of the analysis formula and improve its usage with reference to the interaction between the launching nose and the upper section; and a prismatic analysis formula modified by displacing a diaphragm's weight by a concentrated load in order to improve the accuracy of the existing analysis formula that assumes the launching nose section as the equivalent section. To judge the accuracy and usage of two analysis formulas proposed, we have compared and analyzed computational structural analysis programs and existing analysis formulas based on actual ILM bridge data. As a result, all of two reveal the superior accuracy and also their usage has been improved by the simplification of analysis formulas.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.1
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• pp.87-98
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• 1998

This study was undertaken to determine whether Bombycis Corpus extract (Bom) has antioxidant action. Kidney tissues were exposed to t-butylhydroperoxide (t-BHP) to induce oxidative stress. Lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation, and cell injury was estimated by measuring lactate dehydrogenase (LDH) release in rabbit renal cortical slices. t-BHP increased lipid peroxidation and LDH release in a dose-dependent manner over the concentration range of 0.1-1 mM. Such effects of t-BHP on lipid peroxidase and LDH release were prevented by 0.5% Bom. When tissues were treated with t-BHP in the presence of various concentrations of Bom, lipid peroxidation and LDH release were dose-dependently inhibited by Bom. Bom at 1 and 2% concentrations inhibited lipid peroxidation and LDH release in normal tissues. Bom at 2% concentration increased glutathione peroxidase activity in tissues treated or untreated with 1.0 mM t-BHP. However, catalase activity was not altered by addition of Bom. Bom inhibited generation of reactive oxygen species. These results indicate that Bom inhibits lipid peroxidation and cell injury in tissues treated with or without oxidant and this effect is, at least in part, attributed to increased activity of glutathione peroxidase and a direct sacvenging action.