• Natural Product Sciences
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• v.25 no.3
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• pp.255-260
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• 2019

Piper nigrum L. (Piperaceae), which is a well-known food seasoning, has been used as a traditional medicine for the treatment of vomiting, abdominal pain, diarrhea and anorexia in Korea, China and Japan. Methanol extract from the fruit of P. nigrum was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging activity, and piperine was isolated from the ethyl acetate fraction. To know the antioxidant activity of piperine, we tested the activities of superoxide dismutase (SOD) and catalase together with oxidative stress tolerance and intracellular ROS level in Caenorhabditis elegans. To investigate whether piperine-mediated increased stress tolerance was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain including CF1553. Consequently, piperine enhanced SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Moreover, piperine-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.321-322
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• 1985

• Macromolecular Research
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• v.13 no.3
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• pp.265-272
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• 2005

Polyelectrolyte membranes for humidity-sensing were fabricated using a layer-by-layer adsorption process based on the spontaneous self-assembly of alternating layers of cationic and anionic polymers on a silanized ITO patterned glass substrate. The substrate is dipped successively into dilute solutions of a polyanion and a polycation. The homopolymers and copoymers of diallyldimethylammonium chloride (DDA), allylamine hydrochloride (AA), 2-[(methacryloyloxy)ethyl]trimethyl ammonium chloride (METAC) and vinylbenzyl tributyl phosphonium chloride(VTBPC) were used as the polycations. In this experiment, it was found that the resistance varied according to the chemical structure of the polycation. The resistance varied from $10^7$ to $10^5$ $\Omega$, as the humidity was increased from 60 (relative humidity) to $95\%$RH, which is the range of RH values required for a dew sensor operating at high humidity.

• Macromolecular Research
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• v.11 no.5
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• pp.322-327
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• 2003

Two kinds of mutually cross-linkable copolymers were prepared to be used as humidity-sensing materials. The humidity-sensitive thin films consist of cross-linked polyelectrolytes of the following component: 4-vinylbenzyl dimethyl 2-(dimethylphosphino)ethyl phosphonium chloride (1)/ bis(2-methoxyethyl)itaconate (2)= 3/l, 2/l, 1/1 and 1/2 and 4-vinylbenzyl chloride (3)/ vinylbenzyl tributyl phosphonium chloride (4)= 3/l, 2/l, 1/1 and 1/2. The humidity sensor prepared from the reaction of 1/2= 2/l with 3/4= 2/l showed an average resistance of 723,36.2 and 2.42 ㏀ at 30, 60 and 90%RH, respectively. Temperature dependence, frequency dependence, and response time were measured and the reliability test such as water durability and long-term stability were also estimated.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1041-1045
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• 1999

Three polysiloxaneimide(PSI) as membrane material were prepared by polycondensation of three aromatic dianhydrides(6FDA, BTDA, PMDA) with one siloxane-containing diamine(SIDA, aver. MW. 800). The PSIs were rubbery polymers containing 30~40 wt % of flexible siloxane chains and exhibited low density, high fractional free volume and low surface energy. They were used for pervaporation experiments with 0.05 wt % of four organic aqueous solutions containing ethyl acetate, methylene chloride, trichloroethylene, and toluene, respectively. With increasing hydrophobicity of organic solvents, both pervaporation selectivity and pemeation flux increase.

• Archives of Pharmacal Research
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• v.16 no.3
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• pp.227-230
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• 1993

A new device to detect methamphetamine (MA), amphetamine(A) and its metabolites in urine was developed using the paper strip method and the test tube method of dry chemical reagents. The reagent containing tetrabromophenolphthalein ethyl ester (TBPE) and borax. For the TBPE paper strip method, a device was prepared with a window at each end of the reagent paper strip ; one window is for the sample application, and the other window is for the methylene chloride. The diffused sample from one window reacts with reagent in the paper and produces color at the point where it meets with methylene chloride which has diffused form the other side. A positive smaple produces as red-purple color and the negative sample a greenish color, with a detection limit of 5-10 ppm. The result can be obtained within one minute. For the TBPE test tube method which contains dry reagents, the detection limit is 5 ppm and the result can be obtaineed within 30 seconds, however the carry-on is not as convenient as the paper strip method. The performance of both methods were evlauated by comparing with the results of gas chromatography (GC) and fluorescence polarizaiton immunoassay (FPIA). The results were proven that both methods were useful as primary screening reagents to detect MA in urine and in dry powder.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.710-714
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• 2006

The purpose of this study is to identify the effect of additives and composition on copper surface morphology and mechanical characteristics by copper electrodeposition. Additives such as hydroxy ethyl cellulose(HEC), chloride ion were used in this study. Electrochemical experiments allied to SEM, XRD, AFM and four- point probe were performed to characterize the morphology and mechanical characters of copper in the presence of additives. Among various electrodeposition conditions, the minimum surface roughness of copper foil was obtained when electrodeposited at the current density of 200 mA/$cm^2$ for 68 seconds with 2 ppm of HEC. The minimum value of surface roughness(Rms) was 107.6 nm. It is copper foil is good for electromigration inhibition due to preferential crystal growth of Cu (111) deposited in the electrolyte containing chloride ions(10 ppm) and HEC(1 ppm).

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.239-240
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• 2003

Type I (collagen) and procollagen are reduced in aged human skin. This reduction could result from increased degration by metalloproteinases and from reduced procollagen synthesis and skin collagenase is required for initiation of the degration of type I collagen. In the present study, we study on assay the collagen and collagenase in natural plants using the fibroblast human skin cell. We select the 15 kind of plants used to herbal and 4 kind of fraction(by methylene chloride, ethyl acetate, n-butanol, water). Among these extract, the ethyl acetate fraction from benincasa hispida/prunus persica, trichosanthes kiriowii, trogopterus xanthipes and methylene chloride fractions from benincasa hispida/prunus persica, torilis japonica and n-butanol fraction from cnidium officinale, chrysanthemum sibiricum were selected for further experiments as they exhibited distinctive amount of collagen compared to other natural extracts. These extracts were again subjected to collagenase assay test. Benincasa hispida/prunus persica extract was shown to have exellent collagen synthesis activity from result of the collagen assay test and the other extract was shown to have over 130% of collagen synthesis activity. But, in the study of collagenase assay test just only trogopterus xanthipes extract was shown to have collagenase inhibition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.21-27
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• 2006

Effects of root, stem and leaf extracts of Zanthoxylum piperitum on the inhibition of lipid peroxidation in the hepatic microsome of rat, DPPH radical scavenging activity, soybean lipoxygenase activity and activated partial thromboplastin times (APTT) were examined in vitro. The highest inhibition of hepatic microsomal lipid peroxidation was observed by ethyl acetate fraction of the root and stem extracts. The high inhibition of lipid peroxidation was observed in the leaf, the root and the stem in order. The DPPH radical scavenging activity of ethyl acetate fraction was higher than that of n-butanol fraction and it was similar to the root and the steam extract. It was similar to the inhibition of hepatic microsomal lipid peroxidation. The DPPH radical scavenging activity was the highest in 0.50 mg/mL of ethyl acetate fraction, and it was 4.4-fold higher than that of a-tocopherol, as an antioxidant standard. The DPPH radical scavenging activity was dependent on the extract concentration in the range of $0.12\~5.00$ mg/mL. The soybean lipoxygenase activity of ethyl acetate fraction was higher than that of n-butanol fraction and it was similar to the root and the stem extracts. The soybean lipoxygenase activity was the highest in 0.50 mg/mL of ethyl acetate fraction. The soybean lipoxygenase activity was dependent on the extract concentration in the range of $0.12\~5.00$ mg/mL. The leaf extract showed the highest antithrombogenic effect followed by the stem and then the root extract. The activated partial thromboplastin times were dependent on the extract concentration in the range of $0.10\~2.00$ mg/mL.

• Journal of Pharmaceutical Investigation
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• v.34 no.5
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• pp.369-377
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• 2004

The objective of this study was to investigate the patterns of protein leaching to an external phase during an ethyl acetate-based, double emulsion microencapsulation process. An aqueous protein solution (lactoglobulin, lysozyme, or ribonuclease; $W_1$) was emulsified in ethyl acetate containing poly-d,l-lactide-co-glycolide 75:25. The $W_1/O$ emulsion was transferred to a 0.5% polyvinyl alcohol solution saturated with ethyl acetate $(W_2)$. After the double emulsion was stirred for 5, 15, 30, or 45 min, additional 0.5% polyvinyl alcohol $(W_3)$ was quickly added into the emulsion. This so-called quenching step helped convert emulsion microdroplets into microspheres. After 2-hr stirring, microspheres were collected and dried. The degree of protein leaching to $W_2$ and/or $W_3$ phase was monitored during the microencapsulation process. In a separate, comparative experiment, the profile of protein leaching to an external phase was investigated during the conventional methylene chloride-based microencapsulation process. When ethyl acetate was used as a dispersed solvent, proteins continued diffusing to the $W_2$ phase, as stirring went on. Therefore, the timing of ethyl acetate quenching played an important role in determining the degree of protein microencapsulation efficiency. For example, when quenching was peformed after 5-min stirring of the primary $W_1/O$ emulsion, the encapsulation efficiencies of lactoglobulin and ribonuclease were $55.1{\pm}4.2\;and\;45.3{\pm}7.6%$, respectively. In contrast, when quenching was carried out in 45 min, their respective encapsulation efficiencies were $39.6{\pm}3.2\;and\;29.9{\pm}11.2%$. By sharp contrast, different results were attained with the methylene-chloride based process: up to 2 hr-stirring of the primary and double emulsions, less than 5% of a protein appeared in $W_2$. Afterwards, it started to partition from $W_1\;to\;W_2/W_3$, and such a tendency was affected by the amount of PLGA75:25 used to make microspheres. Different solvent properties (e.g., water miscibility) and their effect on microsphere hardening were to be held answerable for such marked differences observed with the two microencapsulation processes.