• 약학회지
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• 제40권5호
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• pp.522-531
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• 1996

5-fluorouracil(5-FU) derivatives synthesized with four N-acyloxycarbonyl group such as 1-(N-t-butyloxycarbonyl)glycyloxymethyl-5-FU(BGFU), 1-(N-t-butyloxycarbonyl)leucyloxymethy l-5-FU(BLFU), 1-(N-t-carbobenzyloxymethyl)glycyoxymethyl-5-FU(CGFU) and 1-(N-t-carbobenzyloxymethyl)leucyloxymethyl-5-FU(CLFU) were entrapped into liposomes with different lipid compositions. The entrapment efficiency and release rate of drugs from each liposomes were evaluated. The particle size of liposomes, cytotoxicity and stability of drug-entrapped in liposomes were evaluated. The entrapment efficiency in 5-FU derivatives liposomes was dependent on the lipophilicity of N-acyloxymethyl derivatives. The drug entrapment efficiency also increased on the content of lipid increased up to 200mcmol of lipid per milliliter of liposomal solution. However, inclusion of additives such as cholesterol, dicetylphosphate and stearylamine decreased the entrapment efficiency. The mean particle size and size distribution were varied with lipid compositions and lipophilicity of prodrugs. The release rates of drugs from liposomes were not affected by additives, but those of BGFU and CGFU entrapped in liposomes with cholesterol decreased. Cytotoxicity of BLFU and CLFU entrapped in liposomes decreased by 3~5 fold compared with those of free two prodrugs. Liposome-entrapped 5-FU prodrugs were more stable either at pH 7.4 or in human plasma. Especially, 5-FU prodrugs entrapped in liposome with dipalmitoylphosphatidylcholine(DMPC) was the most stable in human plasma. Compared with free BLFU, BLFU entrapped in DMPC liposome showed a superior antitumor activity at all doses used. In contrast, CLFU entapped in liposomes were more toxic than free prodrug.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1135-1140
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• 2012

An electrochromatographic microchip with carboxyl-group-derivatized mono-disperse silica packing was prepared from the corresponding colloidal silica solution by utilizing capillary action and self-assembly behavior. The silica beads in water were primed by the capillary action toward the ends of cross-patterned microchannel on a cyclic olefinic copolymer (COC) substrate. Slow evaporation of water at the front of packing promoted the self-assembled packing of the beads. After thermally binding a cover plate on the chip substrate, reservoirs for sample solutions were fabricated at the ends of the microchannel. The packing at the entrances of the microchannel was silver coated to fix utilizing an electroless silver-plating technique to prevent the erosion of the packed structure caused by the sudden switching of a high voltage DC power source. The electrochromatographic behavior of the microchip was explored and compared to that of the microchip with bare silica packing in basic borate buffer. Electrophoretic migration of Rhodamine B was dominant in the microchip with the carboxyl-derivatized silica packing that resulted in a migration approximated twice as fast, while the reversible adsorption was dominant in the bare silica-packed microchip. Not only the faster migration rates of the negatively charged FITC-derivatives of amino acids but also the different migration due to the charge interaction at the packing surface were observed. The electrochromatographic characteristics were studied in detail and compared with those of the bare silica packed microchip in terms of the packing material, the separation potential, pH of the running buffer, and also the separation channel length.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.65-70
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• 2006

An amperometric glucose biosensor has been developed based on the use of the nanoporous composite film of sol-gel-derived zirconia and perfluorosulfonated ionomer, Nafion, for the encapsulation of glucose oxidase (GOx) on a platinized glassy carbon electrode. Zirconium isopropoxide (ZrOPr) was used as a sol-gel precursor for the preparation of zirconia/Nafion composite film and the performance of the resulting glucose biosensor was tuned by controlling the water content in the acid-catalyzed hydrolysis of sol-gel stock solution. The presence of Nafion polymer in the sol-gel-derived zirconia in the biosensor resulted in faster response time and higher sensitivity compared to those obtained at the pure zirconia- and pure Nafion-based biosensors. Because of the nanoporous nature of the composite film, the glucose biosensor based on the zirconia/Nafion composite film can reach 95% of steady-state current less than 5 s. In addition, the biosensor responds to glucose linearly in the range of 0.03-15.08 mM with a sensitivity of 3.40 $\mu$A/mM and the detection limit of 0.037 mM (S/N = 3). Moreover, the biosensor exhibited good sensor-to-sensor reproducibility (~5%) and long-term stability (90% of its original activity retained after 4 weeks) when stored in 50 mM phosphate buffer at pH 7 at 4 ${^{\circ}C}$.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.529-534
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• 1996

A high-performance liquid chromatographic (HPLC) assay has been developed for the determination of ketorolac in human serum using a new extraction method with a good recovery. Human serum samples (1.0 ml) spiked with known concentrations of ketorolac tromethamine and 10${\mu}g$ of ketoprofen as the internal standard (IS) were acidified with 200${\mu}l$ of 1 N HCl and extracted with 7 ml of n-hexane-ether (7:3 v/v). Extracts were centrifuged and organic layer was back-extracted with 400${\mu}l$ of 0.1% tromethamine solution. Twenty .mu.l of centrifuged aqueous layer was injected onto a reversed-phase octyl column and eluted with a mixture of acetonitrile, water, methanol, and triethylamine [35:55:10:0.1 (v/v), pH 3.0] at a flow rate of 1.0 ml/min. Ultraviolet detection of ketorolac and IS was carried out at 300 nm. The calibration curve obtained using peak area ratios showed a good linearity (in concentration range 10-150 ng/ml $r^2$=O.9944; in range 50-2000 ng/ml, r$^{2}$=0.9998). The mean intra-day accuracy and precision for this HPLC method were found to be 3.6 and 3.7%, respectively. The mean inter-day accuracy and precision were found to be 4.0 and 3.7%, respectively, in the concentration range 50-2000 ng/ml. The recovery of ketorolac from serum was 92.0 $({\pm}5.7)$ % at the concentration of 100 ng/ml. This method proved to be readily applicable to the assay of ketorolac in human serum.

• 한국식품과학회지
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• 제8권2호
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• pp.85-89
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• 1976

Gas chromatography를 이용하여 methylglyoxal, diacetyl 및 triose reductone과 같은 dicarbonyl류(類)를 분리측정(分離測定)할 수 있는 조건(條件)을 실험(實驗)하였던 바 다음과 같은 결과(結果)를 얻었다. 1. MG, DAc, DTR의 혼합물(混合物)에 OPD를 반응시켜 quinoxaline 유도체(誘導體)를 만들고 이것을 클로로포름으로 추출(抽出)하면 MG 및 DAc는 거의 100%추출(抽出)되었고, DTR은 에틸에테르에 추출(抽出)되었다. 2. SE-30을 충진제로하여 얻어진 column 조건(條件)에서 MG-OPD와 DAc-OPD는 완전히 분리측정(分離測定)할 수 있었다. 3. 당류중(糖類中) glucose의 OPD 축합물형성조건(縮合物形成條件)은 D-glucose 180mg을 0.1N-NaOH 용액 10ml에서 5분간(分間) 가열후 OPD와 반응(反應)시켜 pH 6. 0에서 클로로포름으로 추출(抽出)하여 GLC에 겉면 5개의 peak가 나타났고, 그 중에서 2개는MG-OPD와 DAo-OPD임을 확인하였다. 그러나 중성(中性) 및 산성가열(酸性加熱)인 경우는 peak가 확실치 않았다.

• Food Science and Biotechnology
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• 제16권1호
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• pp.83-89
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• 2007

In our study, lactic acid bacteria (LAB)-fermented whey solutions were applied in the soybean soaking process to minimize bacterial contamination and to enrich the biologically functional components of isoflavone and $\gamma$-aminobutyric acid (GABA). Among the 11 LAB tested, Bifidobacteria infantis and a mixed culture (Lactobacillus acidophilus, Bifidobacteria lactis, and Streptococcus thermophilus; ABT-3) displaying the greatest $\beta$-glucosidase activity were selected to produce improved biologically functional soybean preparations. In the soybean soaking processing (without water spraying), the LAB-cultured 10% whey solution was used to soak and to ferment the soybeans and the fermented soybeans were finally dried by heat-blowing at $55^{\circ}C$. The processing conditions used in this study demonstrated that the final soybean product had a reduced contamination by aerobic and coliform bacteria, compared to raw soybeans, likely due to the decrease in pH during LAB fermentation. The aglycone content of the isoflavone increased up to 44.6 mg per 100 g of dried soybean by the processing method, or approximately 8-9 times as much as their initial content. The GABA contents in the processed samples increased as the processing time of soaking-fermentation proceeded as well. The soybean sample that fermented by ABT-3 culture for 24 hr showed the greatest increase in GABA content (23.95 to 97.79 mg/100 g), probably as a result of the activity of glutamate decarboxylases (GAD) released from the soybean or produced by LAB during the soaking process.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.122-129
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• 2005

Chlorine dioxide $(ClO_2)$ treatment was evaluated for microbial growth inhibition and its effects on the quality of vacuum-packaged chicken breasts. Chicken breast samples were treated with 3, 50, and 100 ppm of $ClO_2$ solution, respectively. After $ClO_2$ treatment, chicken breast samples were individually vacuum-packaged and stored at $4^{\circ}C$, a typical storage temperature for meat and meat product, for 7 days. The vacuum-packaged chicken breasts treated with $ClO_2$ had significantly lower total bacteria, yeast and mold, total coliform, and Salmonella spp. were significantly reduced by $ClO_2$ treatment. $D_{10}-values$ of total bacteria count, yeast and mold, total coliform, and Salmonella spp. in vacuum-packaged chicken breasts was 93, 83, 85, and 50 ppm, respectively. The pH of vacuum-packaged chicken breasts decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of vacuum-packaged chicken breasts increased during storage, regardless of $ClO_2$ concentration. $ClO_2$ treatment caused negligible changes in Hunter L, a, and b values in the vacuum-packaged chicken breasts. Sensory evaluation of the vacuum-packaged chicken breasts showed that there were no significant changes among the samples treated with various $ClO_2$ concentration. These results indicate that $ClO_2$ treatment could be useful in improving the microbial safety and quality of meat products.

• Carbon letters
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• 제9권3호
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• pp.203-209
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• 2008

The objective of this work is to study the feasibility of the preparation of the activated carbon (AC) from coconut tree flowers using high temperature fluidized bed reactor (HTFBR). The activating agent used in this work is steam. The reactor was operated at various activation temperature (650, 700, 750, 800 and $850^{\circ}C$) and activation time (30, 60, 120 and 240 min) for the production of AC from coconut tree flowers. Effect of activation time and activation temperature on the quality of the AC preparation was observed. Prepared AC was characterized in-terms of iodine number, methylene blue number, methyl violet number, ethylene glycol mono ethyl ether (EGME) surface area and SEM photographs. The best quality of AC from coconut tree flowers (CFC) was obtained at an activation temperature and time of $850^{\circ}C$ and 1 hr restectively. The effectiveness of carbon prepared from coconut tree flowers in adsorbing crystal violet from aqueous solution has been studied as a function of agitation time, carbon dosage, and pH. The adsorption of crystal violet onto AC followed second order kinetic model. Adsorption data were modeled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity $q_m$ was 277.78 mg/g., equilibrium time was found to be 180 min. This adsorbent from coconut tree flowers was found to be effective for the removal of CV dye.

• 해양환경안전학회지
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• 제25권7호
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• pp.974-981
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• 2019

미세먼지발생 문제는 커다란 사회적 문제로 대두되고 있다. 선박에서는 주 추진 동력원으로 디젤엔진을 주로 사용하고 있다. 본 연구에서는 디젤엔진에서 발생하는 미세먼지로 알려진 입자상 물질을 줄이기 위해서 디젤엔진의 후처리시스템으로 사용 중인 DPF(디젤미립자 필터, Diesel particulate filter)를 소개하고자 한다. DPF의 소재로는 Cordierite와 SiC (Silicon carbide)의 두 가지가 사용되고 있다. 본 논문에서는 SiC DPF에 사용되는 접합제의 물성 향상을 위해서 기존 접합제로 사용된 SiC 계열의 물질 대신 코디얼라이트를 사용하여 열팽창계수 변화를 통한 고온 변형에 대한 열 내구성을 평가하였으며, 접합제와 Segment 사이의 결합을 결정짓는 바탕제에 주성분인 실리카졸의 pH 변화에 따른 물성 변화를 확인하였다. 이를 기반으로 실리카 졸의 반응성을 높이기 위해 Siline계 커플링제를 첨가하거나 SiC를 일부 첨가함으로써 접합제의 물성 변화의 영향에 대해서 실험을 통하여 확인하였다.

• 한국식품영양과학회지
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• 제32권6호
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• pp.937-941
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• 2003

재래종 적갓(Brassica juncea czerniak et coss)을 주재료로 담금하여 발효시킨 적갓김치(red mustard leaf kimchi, RML kimchi)의 crude anthocyanin(CA) 및 refined anthocyanin(RA) 획분들에 대한 항산화성을 규명하였다. 발효된 적갓김치는 산도 0.72(%), pH 4.6 그리고 crude anthocyanin 함량(건조물기준)은 49.4 mg/g이었다. 동결건조 적갓김치로부터 얻어진 조색소용액 (crude pigment solution)을 계통 추출분획하여 증류수 획분, methanol 획분, TFA-methanol (CA) 획분을 얻었으며, CA 획분을 계속 분획하여 정제된 5개의 정제된 RA 획분(Fr.1, Fr.2, Fr.3, Fr,4, Fr.5)을 얻었다. 이들의 항산화 활성을 linoleic acid의 autoxidation system에서 peroxide formation 억제능과 DPPH($\alpha$, $\alpha$＇-diphenyl-$\beta$-picrylhydrazyl)의 free radical 소거능에 대하여 실험하였다. 그 결과 조색소용액 분획물 중 CA 획분이 항산화능이 높았고, CA 획분으로부터 얻어진 RA 획분 중 Fr.3이 가장 높은 항산화성을 보였다. 특히 Fr.3은 적갓김치의 대표적인 anthocyanin이었고 항산화 활성은 $\alpha$-tocopherel보다는 낮았으나 그것에 접근하는 유사한 특성을 보였다. 그리고 그 활성은 지질의 과산화 억제능과 수소공여성에서 다같이 비슷한 수준의 항산화성을 보였다.