• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.113-124
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• 2017

Cotton aphid (Aphis gossypii) and green peach aphid (Myzus persicae) are serious pests damaging various crops including vegetables such as pepper, cucumber, and Chinese cabbage. We conducted a study to control two aphids with secondary metabolite of entomopathogenic fungus Beauveria bassiana. A B. bassiana was already selected as a high virulence isolate against cotton aphid and green peach aphid. The culture filtrate of the isolate showed high pathogenicity against both aphids as 100% mortality against cotton aphid 3 days after treatment and 99% against green peach aphid 5 days after treatment. A different fraction extracts with $CHCl_3$ : MeOH of B. bassiana culture filtrate (30:1, 50:1, 70:1, 90:1, 100:1; v/v) through silica gel column chromatography showed different control effect to aphids. Among them, 50:1 ($CHCl_3$ : MeOH) fraction had highest mortality as 77.3% and 75.4% against A. gossypii and M. persicae, respectively. A mixture of each fraction (1:1) had no synergistic effects because control effect of every mixture was lower than only 50:1 extract; for example, mortality of 50:1 + 70:1 showed $2^{nd}$ highest as 72% of cotton aphid and 70.2% of green peach aphid and other mixtures were lower than these values. In future we will study the identification and mass production of aphicidal compound isolated from 50:1 fraction to develop stable aphid control agent.

• Macromolecular Research
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• v.17 no.10
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• pp.734-738
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• 2009

Biodegradable, pH-sensitive, glycol chitosan (GC) hydrogels were prepared using divinyl adipate (DVA) as a crosslinker and acetic acid as a catalyst. DVA has highly reactive double vinyl ester groups and GC contains a high density of hydroxyl groups, with two in every glucosamine unit. The transesterification reaction between vinyl esters and hydroxyl groups produced crosslinked GC hydrogels. The initial crosslinking reaction was monitored by measuring the viscosity of the reaction mixture. When DVA was added to the GC solution and heated to $50^{\circ}C$, the viscosity of the GC solution gradually increased, implying a crosslinking reaction and hydrogel formation. A new peak from the ester group was observed in the FTIR spectra of the GC hydrogels, confirming the crosslinking reaction. The synthesized GC hydrogel showed pH-dependent water absorbency, mainly due to the presence of amine groups ($-NH_2$) at the C-2 position of the glucosamine unit of GC. The water absorbency greatly increased at acidic pH and slightly decreased at alkaline pH. The GC hydrogel gradually degraded in $37^{\circ}C$ water due to hydrolysis of the ester bonds, which were intermolecular crosslinking sites. A red dye, 5-carboxyltetramethyl-rhodamine (CTMR), was entrapped in the GC hydrogels as a model compound. CTMR was released from GC hydrogels in two steps: an initial burst release mainly due to desorption and diffusion, and a second sustained release possibly due to gradual degradation.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3449-3453
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• 2013

Background: Telomerase has been considered as an attractive molecular target for breast cancer therapy. The main objective of this work is to assess the inhibitory effects of silibinin and curcumin, two herbal substances, on telomerase gene expression in breast cancer cells. Materials and Methods: For determination of cell viability tetrazolium-based assays were conducted after 24, 48, and 72 h exposure times and expression of human telomerase reverse transcriptase gene was measured with real-time PCR. Results: Each compound exerted cytotoxic effects on T47D cells and inhibited telomerase gene expression, both in a time-and dose-dependent manner. The mixture of curcumin and silibinin showed relatively more inhibitory effect on growth of T47D cells and hTERT gene expression as compared with either agent alone. Conclusions: These findings suggest that cell viability along with hTERT gene expression in breast cancer cells could be reduced by curcumin and silibinin.

• Geomechanics and Engineering
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• v.13 no.4
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• pp.535-570
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• 2017

There are only few cases where cause and location of failure of a rock structure are limited to a single discontinuity. Usually several discontinuities of limited size interact and eventually form a combined shear plane where failure takes place. So, besides the discontinuities, the regions between adjacent discontinuities, which consist of strong rock and are called material or rock bridges, are of utmost importance for the shear strength of the compound failure plane. Shear behaviour of persistent and non-persistent joint are different from each other. Shear strength of rock mass containing non-persistent joints is highly affected by mechanical behavior and geometrical configuration of non-persistent joints located in a rock mass. Therefore investigation is essential to study the fundamental failures occurring in a rock bridge, for assessing anticipated and actual performances of the structures built on or in rock masses. The purpose of this review paper is to present techniques, progresses and the likely future development directions in experimental testing of non-persistent joint failure behaviour. Experimental results showed that the presence of rock bridges in not fully persistent natural discontinuity sets is a significant factor affecting the stability of rock structures. Compared with intact rocks, jointed rock masses are usually weaker, more deformable and highly anisotropic, depending upon the mechanical properties of each joint and the explicit joint positions. The joint spacing, joint persistency, number of rock joint, angle of rock joint, length of rock bridge, angle of rock bridge, normal load, scale effect and material mixture have important effect on the failure mechanism of a rock bridge.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.32-39
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• 2007

The measurement of physicochemical properties of ASR incineration ash has been carried dot and the preparation of light-weight material has also been performed using ASR ash for recycling point of view as building or construction materials. For this aim, chemical composition, particle size distribution, and heavy metal leachability were examined for 2 bottom ashes and 4 fly ashes obtained from the domestic ASR incinerator. In the present work, attempt has been made to prepare the lightweight material using boiler ash as a raw material, which is prepared by forming the mixture of boiler ash, lightweisht filler and inorganic binder and followed by calcination at elevated temperature. As a result, the content of Cu in bottom ash was as high as about 3wt% so that the recovery of Cu from ash was required. The major compound of SDR #5 and Bag filter #6 was found to be $CaCl_2{\cdot}Ca(OH)_2{\cdot}H_2O\;and\;CaCl_2{\cdot}4H_2O$, respectively. It is thought that heavy metal teachability of lightweight material prepared with boiler ash was significantly decreased due to the encapsulation or stabilization of heavy metal compounds.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.323-327
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• 2010

A high performance liquid chromatographic (HPLC) method for the simultaneous determination of dictamine, obacunone and fraxinellone was established for the quality control of traditional herb Dictamnus dasycarpus cortex. Separation and quantification were successfully achieved with a Shiseido C18 column ($5\;{\mu}m$, 4.6 mm I.D. ${\times}$ 250 mm) by gradient elution of a mixture of methanol and water at a flow rate of 1.0 ml/min. The diode-array UV/Vis detector (DAD) was used for the detection and the wavelength for quantification was set at 236 nm. The presence of dictamine, obacunone and fraxinellone in this extract was ascertained by retention time, spiking with each authentic standard and UV spectrum. All three compounds showed good linearity ($r^2$ > 0.999) in relatively wide concentration ranges. The R.S.D. recovery of each compound was 101.0~103.7% with R.S.D. values less than 1.0%. This method was successfully applied to the determination of contents of dictamine, obacunone and fraxitnellone in three commercial products of D. dasycarpus cortex. These results suggest that the developed HPLC method is simple, effective and could be readily utilized as a quality control method for commercial products.

• Natural Product Sciences
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• v.14 no.3
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• pp.147-151
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• 2008

A high performance liquid chromatographic (HPLC) method for the simultaneous determination of marker constituents, baicalin and glycyrrhizin was established for the quality control of traditional herbal medicinal preparation, Eul-Ja-Tang (EJT). Separation and quantification were successfully achieved with a Waters XTerra RP18 column ($5{\mu}m$, 4.6 mm I.D. ${\times}$ 150 mm) by gradient elution of a mixture of acetonitrile and water containing 0.03% phosphoric acid (pH 2.03) at a flow rate of 1.0 mL/min. The diode-array UV/VIS detector (DAD) was used for the detection and the wavelength for quantification was set at 250 nm. The presence of baicalin and glycyrrhizin in this decoction was ascertained by retention time, spiking with each authentic standard and UV spectrum. Both baicalin and glycyrrhizin showed good linearity ($r^2$ > 0.999) in a relatively wide concentration ranges. The R.S.D. for intra-day and inter-day precision was less than 5% and the limits of detection (LOD) were about 30 ng. The mean recovery of each compound was 99.5 - 101.2% with R.S.D. values less than 4.0%. This method was successfully applied to the determination of contents of baicalin and glycyrrhizin in three commercial products of EJT, which resulted in the difference in the contents of these compounds. These results suggest that the developed HPLC method is simple, effective and could be readily utilized as a quality control method for commercial EJT products.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.441-445
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• 2011

This research was conducted to investigate the influence of variouis organic substrates on growth and yield of organically grown ginseng seedlings in a shaded plastic house. In the investigation of optimal substrate, the eight substrate were formulated by adjusting blending rate of peatmoss, perlite, coir dust(coco peat), and vermiculite. Then, the changes in physico chemical properties of root substrates as well as their influences on the growth characteristics and yield were determined at six months after sowing. The elevation of the blending rate of peatmoss from 50% to 70% with decrease in the rate of inorganic component (mixture of perlite and vermiculite) from 50 to 30% resulted in the increase in container capacities and decrease in total porosities and air-filled capacities. The concentrations of $NH_4-N$, $P_2O_5$ and K increased as the incorporation rate of castor seed meal, phosphate ore, and langbenite, respectively, were elevated during the root medium formulations. The PPV-1 and PPV-4 substrates produced high stem length, stem diameter, shoot fresh weight, leaf area and root length among eight substrate. Root fresh weight was heaviest in PPV-4 compound nursery media. The results of this experiment will be utilized in the new substrate application for ginseng organic culture in shaded vinyl house.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.75-84
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• 2011

Atopic dermatitis is a chronic inflammatory skin disease associated with cutaneous hyper-reactivity to environmental triggers. In order to develop effective therapeutic herbal extracts for atopic dermatitis, cytotoxicity, antioxidant, anti-inflammatory and anti-allergic activities were investigated for various herbal extracts. Among candidate extracts, we selected Aloe vera L. (AV), Viola mandshurica W. Becker (VM), Punica granatum L. (PG), Dendrobium nobile L. (DN) and mixture of the above extracts (MX) for further investigations. All of them did not show cytotoxic activities to macrophage RAW264.7 cells below the concentration of 100 ppm. All showed antioxidant, anti-inflammatory and anti-allergic effects, although to various extents. In antioxidant effects, AV showed the highest effect, followed by PG and VM, while DN did the lowest. In evaluation for anti-inflammatory activities in macrophage RAW264.7 cells, AV and DN inhibited almost completely the LPS-induced production of nitric oxide, while AV, DN and VM showed strong inhibitory activities on the LPS-induced production of TNF-${\alpha}$. In anti-allergy effect in mast cell HMC-1, DN showed the highest effect, followed by AV and PG, while VM did the lowest. In the topical allergy reaction induced by compound 48/80 in Sprague-Dawley rat, DN exhibited significant anti-allergic effect, while PG, VM and AV did slight effect. These results suggest that AV, VM, PG and DN have antioxidant, anti-inflammatory and anti-allergic activities, and thus have the potential to reduce and alleviate the symptoms of atopic dermatitis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.325-331
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• 2011

Nonylphenol (NP), which is well known as an endocrine disrupter, has been detected widely in untreated sewage or waste water streams. Given the necessity of discovering an eco-friendly method of degrading this toxic organic compound, this study was conducted to isolate NP-degrading microorganisms from the aqueous environment. NP-degrading microbes were isolated through NP-containing enrichment culture. Finally, a microbial consortium, SW-3, capable of degrading NP with high efficiency, was selected from the mixture sample. The microbial consortium SW-3 was able to degrade over 99% of 100 ppm NP in the culture medium for 40 days at $25^{\circ}C$. The microbial consortium SW-3 seemed to utilize NP as a carbon source, since NP was the sole carbon source in the culture medium. In order to isolate the NP-degrading bacterium, we further conducted single colony isolation using the microbial consortium SW-3. Four strains isolated from SW-3 exhibited lower NP-degradation efficiency than that of SW-3, suggesting that NP was degraded by the co-metabolism of the microbial consortium. We suggest that the microbial consortium obtained in this study would be useful in developing an eco-friendly bioremediation technology for NP degradation.