• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.148-154
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• 2007

Volatile components of the essential oils of Satsuma mandarin (C. unshiu), Dangyuza (C. grandis), Yuza (C. junos), Byungkyul (C. playtymamma), Jinkyul (C. sunki), and Hakyul (C. natsudaidai) grown in Jeju Island were isolated from the fruit peels by hydro distillation and determined by GC-MS. GC-MS analysis identified 58 compounds, with main components being d-limonene $(64.01{\sim}79.34%),\;{\beta}-myrcene\;(3.01{\sim}26.53%),\;{\gamma}-terpinene\;(0.11{\sim}12.88%),\;{\beta}-pinene\;(0.78{\sim}4.74%),\;and\;{\alpha}-pinene\;(1.01{\sim}2.55%)$. Differences in compositions and contents of the essential oils were observed among citrus varieties. Effects of citrus oils on growth inhibitions of Escherchia coli, Staphyllococcus epidermidis, and Candida albicans were investigated using disc diffusion assay and minimal inhibitory concentration (MIC) assay. The essential oils inhibited growths of the test organisms, exhibiting higher levels of activity against Gram-positive S. epidermidis (MIC values $0.04{\sim}0.17mg/mL$), whereas Gram-negative E. coli was moderately resistant (MIC values $1.66{\sim}20.30mg/mL$). MIC of citrus essential oils ranged from $0.82{\sim}23.69mg/mL$ against C. albicans. The essential oils obtained from C. sunki, C. grandis, and C. playtymamma showed the highest antimicrobial activities against S. epidermidis and C. albicans, indicating their potential as natural antimicrobial agents.

• Journal of Pharmaceutical Investigation
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• 제40권2호
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• pp.79-84
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• 2010

Osteoporosis was traditionally defined by the occurrence of nontraumatic fractures, especially of the spine, in the setting of low bone mass. Bisphosphonates are an important group of therapeutic agents for the management of osteoporosis, as they inhibit bone resorption and increase bone density, thereby potentially decreasing fracture risk. Risedronate sodium is a bisphosphonate class used by oral formulation. In this study, risedronate was transdermally delivered by iontophoresis. Effects of polarity, pH, current density, and drug concentration were studied using a side-by-side diffusion cell including the hairless mice skin. In addition we studied effect of enhancers. The flux was evaluated by HPLC/UV system. The amount of transported drug under iontophoretic delivery was approximately 186 fold higher than that under passive delivery. Flux was proportional to the increase of drug concentration and current density. The flux was observed about 0.68mg/$cm^2$ when the amout of Propyleneglycol monolaurate (PGML) used 1% as enhancer. Results indicated that iontophoresis is an effective method for transdermal administration of risedronate sodium

• 한국초전도ㆍ저온공학회논문지
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• 제16권3호
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• pp.21-25
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• 2014

As wireless power transfer (WPT) technology using strongly coupled electromagnetic resonators is a recently explored technique to realize the large power delivery and storage without any cable or wire, this technique is required for diffusion of electric vehicles (EVs) since it makes possible a convenient charging system. Typically, since the normal conducting coils are used as a transmitting coil in the CPT system, there is limited to deliver the large power promptly in the contactless EV charging system. From this reason, we proposed the combination CPT technology with HTS transmitting antenna, it is called as, superconducting contactless power transfer for EV (SUWPT4EV) system. As the HTS coil has an enough current density, it can deliver a mass amount of electric energy in spite of a small scale antenna. The SUCPT4EV system has been expected as a noble option to improve the transfer efficiency of large electric power. Such a system consists of two resonator coils; HTS transmitting antenna (Tx) coil and normal conducting receiver (Rx) coil. Especially, the impedance matching for each resonator is a sensitive and plays an important role to improve transfer efficiency as well as delivery distance. In this study, we examined the improvement of transmission efficiency and properties for HTS and copper antennas, respectively, within 45 cm distance. Thus, we obtained improved transfer efficiency with HTS antenna over 15% compared with copper antenna. In addition, we achieved effective impedance matching conditions between HTS antenna and copper receiver at radio frequency (RF) power of 370 kHz.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.227-232
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• 2012

Galectins are generally believed to be potential candidates for use in the development of novel antiinflammatory agents or as selective modulators of the immune response. In particular, galectin-9 exhibits some of the extracellular functions, including cell aggregation, adhesion, chemoattraction, activation, and apoptosis. Tl-galectin (Tl-gal, galectin-9 homologue gene) was isolated from an adult worm of the Toxascaris leonina. The full-length Tl-gal gene, which was incorporated into pET-28a, was overexpressed in E. coli and purified by nickel affinity and gel filtration chromatographies. The purified Tl-gal was crystallized using the hangingdrop vapor-diffusion method. The crystal belonged to the tetragonal space group $P4_1$, with unit-cell parameters of a = b = $75.7\AA$ and c = $248.4\AA$. The crystals were obtained at $20^{\circ}C$ and diffracted to a resolution of $3.0\AA$. The asymmetric unit contained four molecules of Tl-gal, which gave a crystal volume per protein mass (Vm) of $2.8\AA^3Da^{-1}$ and a solvent content of 54.1%.

• 청정기술
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• 제18권2호
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• pp.123-143
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• 2012

초임계유체기술은 최근 다양한 화학 산업 분야에서 새로운 관심을 모으고 있는 신기술의 하나라 할 수 있다. 초임계유체기술은 높은 용해성, 빠른 침투성, 빠른 물질 이동 등의 초임계유체 장점을 이용한 기술로써 친환경, 에너지 절감, 고효율성을 가진 현재로서 가장 효과적이고 실용적인 기술이라 하겠다. 이러한 특징을 가진 초임계유체기술을 이용한 응용 기술의 잠재력을 분석 및 평가하고 개발하는 것은 필수적이다. 따라서 본 총설에서는 초임계유체기술의 응용 측면에서 초임계유체내에서 고분자 중합 공정의 최적화를 위한 기초자료인 모노머/고분자의 고온 고압에서 초임계유체 내에서의 상거동 현상을 설명하고, 이러한 자료를 통해 초임계유체 내에서 특정물질을 분리 할 수 있는 분자인식고분자의 제조와 성능 평가에 대해 소개하였다.

• 멤브레인
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• 제20권4호
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• pp.326-334
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• 2010

본 연구에서는 고분자전해질 연료전지의 연료가습을 위하여 막 증발법을 적용한 막가습기를 제작하여 특징과 성능을 알아보았다. 막가습기 내부 물의 온도를 $30{\sim}60^{\circ}C$, 연료기체의 유속을 300~3,000 mL/min, 막 가닥수를 10, 50, 100 가닥으로 변화 하였을 때 결과를 dew point로 나타내었다. 그 결과 $60^{\circ}C$일 때 $51.19^{\circ}C$, 900 mL/min일 때 $54.22^{\circ}C$, 100 가닥일 때 $60.03^{\circ}C$로 연료 가습성능이 가장 좋았다. 특히, 막 가습기 물질 전달식의 모델링을 통해 연료전지에 적용할 때 막 가습기 공경 크기에 따른 반응기체의 가습량을 예측하는 것이 가능하였다. 100 W급 스택에 적용하였을 때, 전압과 출력값이 변화되지 않고 안정적으로 작동하였으며 제작한 막 가습기는 기존 기포가습기보다 부피는 훨씬 작으면서도 가습 성능은 우수한 것을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.167-176
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• 2013

A novel bioactive molecule produced by Bacillus thuringiensis subsp. kurstaki Bn1 (Bt-Bn1), isolated from a common pest of hazelnut, Balaninus nucum L. (Coleoptera: Curculionidae), was determined, purified, and characterized in this study. The Bt-Bn1 strain was investigated for antibacterial activity with an agar spot assay and well diffusion assay against B. cereus, B. weinhenstephenensis, L. monocytogenes, P. savastanoi, P. syringae, P. lemoignei, and many other B. thuringiensis strains. The production of bioactive molecule was determined at the early logarithmic phase in the growth cycle of strain Bt-Bn1 and its production continued until the beginning of the stationary phase. The mode of action of this molecule displayed bacteriocidal or bacteriolytic effect depending on the concentration. The bioactive molecule was purified 78-fold from the bacteria supernatant with ammonium sulfate precipitation, dialysis, ultrafiltration, gel filtration chromatography, and HPLC, respectively. The molecular mass of this molecule was estimated via SDS-PAGE and confirmed by the ESI-TOFMS as 3,139 Da. The bioactive molecule was also determined to be a heat-stable, pH-stable (range 6-8), and proteinase K sensitive antibacterial peptide, similar to bacteriocins. Based on all characteristics determined in this study, the purified bacteriocin was named as thuricin Bn1 because of the similarities to the previously identified thuricin-like bacteriocin produced by the various B. thuringiensis strains. Plasmid elution studies showed that gene responsible for the production of thuricin Bn1 is located on the chromosome of Bt-Bn1. Therefore, it is a novel bacteriocin and the first recorded one produced by an insect originated bacterium. It has potential usage for the control of many different pathogenic and spoilage bacteria in the food industry, agriculture, and various other areas.

• 청정기술
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• 제20권1호
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• pp.51-56
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• 2014

본 연구에서는 폴리술폰(polysulfone, PSf)으로 알루미늄 수산화물(aluminum hydroxide, $Al(OH)_3$)을 고정화한 PSf-$Al(OH)_3$ 비드를 제조하였다. 제조한 PSf-$Al(OH)_3$ 비드에 의한 불소 이온 제거실험은 회분식으로 수행하였으며, pH, 초기농도, 공존이온과 같은 변수들의 영향을 살펴보았다. Langmuir 등온식으로 구한 불소 이온의 최대 제거량은 52.4 mg/g이었으며, 최적 pH 범위는 4~10이었다. PSf-$Al(OH)_3$ 비드에 의한 불소 이온의 제거과정은 전 단계에서 외부물질전달이 나중 단계에서 내부확산이 지배인 것을 알 수 있었다. 또한 PSf-$Al(OH)_3$에 의한 불소 이온의 제거에서 $HCO_3{^-}$, $SO{_4}^{2-}$, $NO_3{^-}$, $Cl^-$와 같은 공존 음이온들은 불소 이온의 제거에 방해를 하는 것으로 나타났다.

• Geomechanics and Engineering
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• 제8권2호
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• pp.283-303
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• 2015

To research and analyze the differential settlements of foundations specifically, site investigations of existing railways and metro were firstly carried out. Then, the centrifugal test was used to observe differential settlements in different position between foundations on the basis of investigation. The theoretical model was established according to the stress diffusion method and Fourier method to establish an analytical solution of embankment differential settlement between different foundations. Finally, theoretical values and experimental values were analyzed comparatively. The research results show that both in horizontal and vertical directions, evident differential settlement exists in a limited area on both sides of the vertical interface between different foundations. The foundation with larger elastic modulus can transfer more additional stress and cause relatively less settlement. Differential settlement value decreases as the distance to vertical interface decreases. In the vertical direction of foundation, mass differential settlement also exists on both sides of the vertical interface and foundation with larger elastic modulus can transfer more additional stress. With the increase of relative modulus of different foundations, foundation with lower elastic modulus has larger settlement. Meanwhile, differential settlement is more obvious. The main error sources in theoretical and experimental values include: (a) different load form; (b) foundation characteristics differences; (c) modulus conversion; (d) effect of soil internal friction.

• Investigative Magnetic Resonance Imaging
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• 제14권2호
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• pp.151-155
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• 2010

일차성 간림프종은 전체 림프절외장기를 침범하는 림프종의 1% 미만에서 나타나는 매우 드문 질환이다. 저자들은 수술로 확진된 일차성 간림프종의 자기공명영상과 병리 소견의 특징을 보고한다. 간세포 특이 조영제를 주입하여 얻은 역동적 조영증강 영상에서 점차적으로 조영증강되어 간내담관암과 유사하게 보였다. 그러나 20분 지연 후 얻은 간담관기 영상과 확산강조영상에서 서로 다른 신호강도를 보이는 세 층의 띠모양의 병변이 특징적으로 보였으며 이는 병리적으로 외층의 생존 종양, 중간층의 괴사된 종양, 및 종양에 둘러싸인 중앙부의 괴사된 간 실질과 일치되는 소견을 보였다.