• Computers and Concrete
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• v.26 no.1
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• pp.31-52
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• 2020

This paper investigates the size dependent effect on the vibration analysis of a porous nanocomposite viscoelastic plate reinforced by functionally graded-single walled carbon nanotubes (FG-SWCNTs) by considering nonlocal strain gradient theory. Therefore, using energy method and Hamilton's principle, the equations of motion are derived. In this article, the effects of nonlocal parameter, aspect ratio, strain gradient parameter, volume fraction of carbon nanotubes (CNTs), damping coefficient, porosity coefficient, and temperature change on the natural frequency are perused. The innovation of this paper is to compare the effectiveness of each mentioned parameters individually on the free vibrations of this plate and to represent the appropriate value for each parameter to achieve an ideal nanocomposite plate that minimizes vibration. The results are verified with those referenced in the paper. The results illustrate that the effect of damping coefficient on the increase of natural frequency is significantly higher than the other parameters effect, and the effects of the strain gradient parameter and nonlocal parameter on the natural frequency increase are less than damping coefficient effect, respectively. Furthermore, the results indicate that the natural frequency decreases with a rise in the nonlocal parameter, aspect ratio and temperature change. Also, the natural frequency increases with a rise in the strain gradient parameter and CNTs volume fraction. This study can be used for optimizing the industrial and medical designs, such as automotive industry, aerospace engineering and water purification system, by considering ideal properties for the nanocomposite plate.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.540-545
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• 2008

An atrium has great potential in natural ventilation aided by buoyance effect. Architectural design of an atrium is very critical to maximize the effect. However, it is not easy of an atrium to have optimum shape for natural ventilation, from the aesthetic and economic point of view. Admitting this condition, we suggested a strategy to promote natural ventilation, which can be adopted only with small design change. At first, we installed BIPV on the top of an atrium to strengthen buoyancy effect, and combine forced ventilation by low pressure fan. To evaluate the performance of the measure, CFD simulation and Energy-Airflow analysis were achieved.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.122-122
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• 2012

The aims of this study were to examine the efficacy of phytochemical compounds of colorants as anti-oxidant agent. The bioactive properties of natural colorants were studied by total phenolic contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and anti-bacterial activity in Escherichial coli. The concentration ($IC_{50}$) of various extracts from colorants required to exert 50% reducing effect on DPPH radical were found to be 0.007-4 mg/ml. Especially, the gallnut (Schlectendalia Chinensis) displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The total phenolic contents (TPC) and restraint of E coli. also analyzed. It was found that gallnut extracts effectively inhibited DPPH radical at a concentration below 0.01 mg/ml. Natural colorant extracts could be of good resources as anti-oxidant and anti-bacterial agents. The results suggest that our study may contribute to the development of natural and functional materials with potential application to reduce oxidative damage.

• Molecules and Cells
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• v.38 no.7
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• pp.630-637
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• 2015

Morus alba root extract (MARE) has been used to treat hyperglycaemic conditions in oriental medicine. Here, we studied whether MARE possesses a cytotoxic effect on neuroblastoma. To check the cytotoxicity generated by MARE was whether relatively higher against the cancer cells rather than normal cells, we chose a neuroblastoma cell line (B103) and a normal cell line (Rat-2). A CCK assay revealed that MARE ($10{\mu}g/ml$) reduced cell viability to approximately 60% compared to an untreated control in B103 cells. But in Rat-2 cells, MARE induced relatively lower cytotoxicity. To investigate the mechanisms underlying the cytotoxic effect of MARE, we used flow cytometry combined with immunoblot analyses. We found that MARE-treatment could accumulate ROS and depolarize mitochondria membrane potential of B103 cells. Further treatment with MARE in B103 cells also could damage DNA and induce apoptosis. An expression study of p-Akt also suggested that there was a reduction in cellular proliferation and transcription along with the process of apoptosis, which was further evidenced by an increase in Bax and cleaved-caspase 3 activity. Together, our findings suggest that MARE produces more cytotoxicity in cancer cells while having a relatively attenuated effect on normal cells. As such, MARE may be a safer option in cancer therapeutics, and it also shows potential for the patients with symptoms of hyperglycemia and cancer.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1653-1658
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• 2012

A new anthracene-containing conjugated molecule was synthesized through the Sonogashira coupling and reduction reactions. 1-Ethynyl-4-hexylbenzene was coupled to 2,6-bis((4-hexylphenyl) ethynyl)anthracene-9,10-dione through a reduction reaction to generate 2,6,9,10-tetrakis((4-hexylphenyl)ethynyl) anthracene. The semiconducting properties were evaluated in an organic thin film transistor (OTFT) and a single-crystal field-effect transistor (SC-FET). The OTFT showed a mobility of around 0.13 $cm^2\;V^{-1}\;s^{-1}$ ($I_{ON}/I_{OFF}$ > $10^6$), whereas the SC-FET showed a mobility of 1.00-1.35 $cm^2\;V^{-1}\;s^{-1}$, which is much higher than that of the OTFT. Owing to the high photoluminescence quantum yield of 2,6,9,10-tetrakis((4-hexylphenyl)ethynyl) anthracene, we could observe a significant increase in drain current under irradiation with visible light (${\lambda}$ = 538 nm, 12.5 ${\mu}W/cm^2$).

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.269-275
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• 2010

P-gp plays a critical role in drug disposition and represents a mechanism for the development of multidrug resistance. Flavonoids, a major class of natural compounds widely present in foods and herbal products, have been shown to inhibit P-gp. Therefore, the aim of this study was to identify new candidate chemosensitizers by screening various plant extracts. The ability of natural plant extracts to inhibit P-gp activity was assessed by measuring cellular accumulation of calcein AM, daunorubicin and vincristine in P-gp overexpressing MDCKII-MDR1 cells. Among more than 800 plant extracts, eight were found to inhibit P-gp activity. Curcuma aromatica extract produced greatest inhibition, followed by Curcuma longa and Dalbergia odorifera extracts. Extracts of Aloe ferox, Curcuma zedoariae rhizome, Zanthoxylum planispinum, and Ageratum conyzoides showed moderate inhibitory effects. Curcumin and quercetin exhibited similar inhibition of P-gpmediated efflux of daunorubicin and vincristine, and flavones had a lesser effect. When chemosensitizing effect was evaluated by measuring daunorubicin sensitivity to MDCKII-MDR1 cells in the presence of natural plant extracts, Curcuma aromatica showed the most potent chemosensitizing effect based on daunorubicin cytotoxicity. In conclusion, natural plant extracts such as Curcuma aromatica can potently inhibit P-gp activity and may have potential as a novel chemosensitizers.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1220-1230
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• 2016

The purpose of this study is to investigate the effect of 20s university student bodybuilders' protein intake differences with resistant exercise(weight training) by 12 weeks on solt lean mass and body composltion. Natural protein(Chicken breast meat) intake group and Whey protein isolates(WPI) intake group are the experimental groups. Conventional meal intake group is the control group. This study proposes a efficient protein diet for weight training. The results were as follows. In the experimental group(natural protein intake), muscle mass and lean body mass was significantly increased, but body fat percentage was significantly decreased. In the experimental group(WPI intake), muscle mass and lean body mass was significantly increased, but body fat percentage was significantly decreased. In the control group(conventional meal intake), muscle mass and lean body mass was insignificantly increased, but body fat percentage was insignificantly decreased. In addition, there was not a significant difference among intake groups, and also not a differentiated effect between natural protein and WPI intake. In conclusion, natural protein and WPI made muscle mass and lean body mass rise, body fat percentage reduced effectively. Only WPI intake(without natural protein intake) was the efficient mean to increase muscle mass and lean body mass, and to decrease body fat percentage.

• Natural Product Sciences
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• v.9 no.4
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• pp.270-272
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• 2003

The methanol extract of Euphorbia milii exhibited strong inhibitory effect on platelet aggregation in the cource of our search for anti-platelet component from succulent plants. Two components, components 1 and 2 were isolated from this plant. 1 was the mixture of 72% of 1-octacosanol (1a) and 28% of 1-triacontanol (1b), and 2 was identified as ${\beta}-sitosterol$. 2 ($IC_{50}$: $195\;{\mu}M$, and $170\;{\mu}M$ respectively) was about two fold stronger than ASA ($IC_{50}$: $420\;{\mu}M$ and $340\;{\mu}M$ respectively) on both collagen and U46619 induced aggregation, while the effect of 1 to platelets was negligible.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.975-979
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• 1994

The experimental and finite element studies of a coaxial cylindrical shell filled with liquid in the annular gap were performed to understand its vibration characteristics. Finite element analysis was achieved by using ANSYS code. Form the investigation of the changing trend of natural frequencies for the change of annular gap we know that the natural frequency of the coaxial cylindrical shell varies according to the mode shape. that is, in case of in-phase mode the natural frequency decrease as annular gap increase, but in case of out-of-phase mode the natural frequency increase. Finite element analysis results show the excellent agreement with the experimental results both in air and in water case, so that analysis on other cases with be possible without experiment.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.143-150
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• 1984

The effect of growth inhibitors on colonial growth of cellulolytic fungus, genus Trichoderma, was investigated to develop a method for the effective screening of various auxotrophs and hypercellulolytic strains. As the results, it was revealed that non-ionic detergents such as Sodium deoxycholate and Triton X-100 were the better ones as a growth inhibitor than Oxgall which has been used to restrict the colony size in genus Trichoderma. Each individual colony remained distinct on minimal plate supplemented with 0.05% Triton X-100 for as long as two or more weeks. The screening of 150 to 200 colonies simultaneous on a single plate was possible in the presence of Triton X-100. The effect of Triton X-100 on simultaneous screening was higher than that of Oxgall by a factor of two.