• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.427-427
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• 2016

Organic-inorganic hybrid perovskite have attracted significant attention as a new revolutionary light absorber for photovoltaic device due to its remarkable characteristics such as long charge diffusion lengths (100-1000nm), low recombination rate, and high extinction coefficient. Recently, power conversion efficiency of perovskite solar cell is above 20% that is approached to crystalline silicon solar cells. Planar heterojunction perovskite solar cells have simple device structure and can be fabricated low temperature process due to absence of mesoporous scaffold that should be annealed over 500 oC. However, in the planar structure, controlling perovskite film qualities such as crystallinity and coverage is important for high performances. Those controlling methods in one-step deposition have been reported such as adding additive, solvent-engineering, using anti-solvent, for pin-hole free perovskite layer to reduce shunting paths connecting between electron transport layer and hole transport layer. Here, we studied the effect of alkali metal halide to control the fabrication process of perovskite film. During the morphology determination step, alkali metal halides can affect film morphologies by intercalating with PbI2 layer and reducing $CH3NH3PbI3{\cdot}DMF$ intermediate phase resulting in needle shape morphology. As types of alkali metal ions, the diverse grain sizes of film were observed due to different crystallization rate depending on the size of alkali metal ions. The pin-hole free perovskite film was obtained with this method, and the resulting perovskite solar cells showed higher performance as > 10% of power conversion efficiency in large size perovskite solar cell as $5{\times}5cm$. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) are analyzed to prove the mechanism of perovskite film formation with alkali metal halides.

• 대한의생명과학회지
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• 제11권4호
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• pp.517-523
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• 2005

The purpose of this study was to determine the effect of rat intestinal a-glucosidase inhibitor; methanol $(80\%)$, ethanol $(80\%)$ and water extract of Schizandra chinensis in Korea (KS: Schizandra chinensis in Korea) and China (CS: Schizandra chinensis in China). When the final concentration was 1 mg/ml for each sample (KS and CS), methanol extract of KS ($IC_{50}$ 1.62 mg/ml) showed $46.8\%$, ethanol extract of KS ($IC_{50}$ 1.48 mg/ml) showed $47.4\%$, water extract of KS ($IC_{50}$ 1.72 mg/ml) showed $46.3\%$ and methanol extract of CS ($IC_{50}$ 8.35 mg/ml) showed $13.3\%$, ethanol extract of CS ($IC_{50}$ 8.05 mg/lml) showed $16\%$, water extract of CS ($IC_{50}$ 8.37 mg/ml) showed $11.54\%$ of inhibitor for p-nitrophenyl $\alpha-D-glucopyranoside$ (pNPG) $\alpha-glcosidase$ activity, respectively. And the contents of total phenol, flavonoid of Schizandra chinensis were measured. When the final concentration was 1mg/ml for each sample (KS and CS), total phenol and flavonoid in KS were higher than CS, respectively. The order superoxide dismutase (SOD) activity $IC_{50}$ values of each solvent extracts of KS were: 2.006 mg/ml methanol extract, 2.304 mg/ml ethanol extract and 2.5 mg/ml water extract, which were higher than that of each solvent extracts CS as: 2.881 mg/ml methanol extract, 3.085 mg/ml ethanol extract and 3.190 mg/ml water extract.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10281-10287
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• 2015

Background: Development of a nanosized polymeric delivery system for erlotinib was the main objective of this research. Materials and Methods: Poly caprolactone-polyethylene glycol-polycaprolactone (PCEC) copolymers with different compositions were synthesized via ring opening polymerization. Formation of triblock copolymers was confirmed by HNMR as well as FT-IR. Erlotinib loaded nanoparticles were prepared by means of synthesized copolymers with solvent displacement method. Results: Physicochemical properties of obtained polymeric nanoparticles were dependent on composition of used copolymers. Size of particles was decreased with decreasing the PCL/PEG molar ratio in used copolymers. Encapsulation efficiency of prepared formulations was declined by decreasing their particle size. Drug release behavior from the prepared nanoparticles exhibited a sustained pattern without a burst release. From the release profiles, it can be found that erlotinib release rate from polymeric nanoparticles is decreased by increase of CL/PEG molar ratio of prepared block copolymers. Based on MTT assay results, cell growth inhibition of erlotinib has a dose and time dependent pattern. After 72 hours of exposure, the 50% inhibitory concentration (IC50) of erlotinib hydrochloride was appeared to be $14.8{\mu}M$. Conclusions: From the obtained results, it can be concluded that the prepared PCEC nanoparticles in this study might have the potential to be considered as delivery system for erlotinib.

• Journal of Pharmaceutical Investigation
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• 제37권4호
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• pp.211-216
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• 2007

The bark of Alnus japonica has been used for the treatment of fever, hemorrhage and diarrehea in oriental traditional medicine. Recently, it was revealed that the diarylheptanoids from the bark of Alnus japonica possess anti-inflammatory activity and are expected to be applicable for atopic dermatitis. In this study, oregonin, one of major active components in the bark of Alnus japonica, was developed in the form of semisolid formulations for topical delivery. Oregonin was incorporated into four ointment bases: O/W cream, W/O cream, hydrophilic ointment and lipophilic ointment. Oregonin release from all formulation prepared was evaluated. Franz cell method and immersion method were employed to characterize the release patterns of drug from each formulation based on solvent availability. O/W cream showed a better release profile than the other formulations when evaluated with Franz cell method with an order of O/W cream, hydrophilic ointment, W/O cream and lipophilic ointment. In the immersion method, hydrophilic ointment showed the greatest release rate at times 1 hour exceeding compared to other bases with an order of hydrophilic ointment, O/W cream, W/O cream and lipophilic ointment. Hydrophilicity and solvent availability of formulation seems to significantly influence the release rate of oregonin from ointment bases. In this study, we successfully characterized the oregon in ointment and found that o/w cream is a promising formulation for the topical delivery of oregonin.

• Natural Product Sciences
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• 제20권3호
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• pp.211-215
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• 2014

Opuntia humifusa, also called as Cheonnyuncho, is a cactus widely cultivated in southern regions of Korea. It has been known to have diverse biological activities, but most of the studies were performed with the MeOH extracts or solvent-partitioned fractions. Furthermore, the efforts to identify the responsible compounds for the biological activities are very limited. In this study, we tested the inhibitory effect of extracts and solvent-partitioned fractions of O. humifusa against LPS-induced nitric oxide (NO) production in Raw264.7 cells. The butanol fractions of O. humifusa efficiently inhibited the production of NO in Raw264.7 cells, but it was not due to the reduction of cell viability. Bioassay-guided isolation of butanol fractions of O. humifusa allowed the isolation of three flavonoids isorhamnetin 3-O-${\beta}$-$\small{D}$-galactosyl-4'-O-${\beta}$-$\small{D}$-glucoside (1), isorhamnetin 3,4'-di-O-${\beta}$-$\small{D}$-glucoside (2) and isorhamnetin 3-O-${\beta}$-$\small{D}$-(6-O-${\alpha}$-$\small{L}$-rhamnosyl)glucoside (3), and one lignan syringaresinol O-${\beta}$-$\small{D}$-glucopyranoside (4). Among them, isorhamnetin 3-O-${\beta}$-$\small{D}$-galactosyl-4'-O-${\beta}$-$\small{D}$-glucoside (1) and isorhamnetin 3,4'-di-O-${\beta}$-$\small{D}$-glucoside (2) exhibited the moderate inhibitory effects against LPS-induced NO production. This is the first time to report anti-inflammatory effects of these compounds.

• 보존과학회지
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• 제25권3호
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• pp.293-298
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• 2009

Polyvinyl butyral (Butvar) 원재와 silane계 첨가제를 iso-propyl alcohol에 용해시킨 도자기 복원용 메움제를 제조하였다. 이는 원하는 정도로 경도의 조절이 가능하고 접착 강도와 전단 강도에서 매우 우수한 결과를 나타내었으며 충진성, 수축성, 도색성 등에서도 일반적으로 사용되는 에폭시계 메움제와 같은 결과들을 나타내고 있었다. 특히, 현재 일반적으로 사용되는 에폭시계 메움제의 문제점인 황변 현상과 복원 가역성을 해결함으로서, 도자기의 복원의 항구성과 지속적인 안정성을 부여할 수 있을 것으로 보인다. 또 본 메움제를 이용하여 삼천사지 분청사기를 복원하였으며 복원 후, 이를 재 용해하여 메움제를 완벽히 제거하는 과정을 통하여 복원의 가역성도 보이고자 하였다.

• 한국자원식물학회지
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• 제25권2호
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• pp.240-245
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• 2012

본 연구에서는 전호추출물의 주름개선에 대한 효능을 측정하기 위하여 인간의 섬유아세포에 전호추출물을 처리하여 총콜라겐과 type I procollagen, MMP-1의 생합성에 미치는 영향을 조사하였다. 전호추출물을 인간 섬유아세포에 처리 시 콜라겐의 생합성은 증가시켰지만, MMP-1의 발현에 대해서는 영향을 미치지 못하였다. 이는 전호추출물이 자외선에 의해 영향을 받는 광노화보다는, 노화에 의해 콜라겐 생합성율이 감소되는 내인성노화에 훨씬 유효함을 시사한다. 전호추출물을 처리시 95% EtOH 추출물의 경우 25%까지 총콜라겐의 생합성을 증가시켰고, EtOAc층은 28%, EtOAc의 E6 소분획의 경우 50% 증가시켰으므로, 콜라겐 생합성에 영향을 미치는 유효성분은 EtOAc층에 대부분 함유되어 있을 것으로 사료되고, 이는 확인되지 않은 미지의 효능 성분이 존재하거나, 다양한 활성 성분들의 상호 작용에 의한 것으로 판단된다. 결론적으로 전호추출물은 콜라겐 생합성을 촉진함으로 내인성노화에 의한 주름생성 및 탄력저하를 개선할 수 있는 천연 유용자원으로 이용할 수 있을 것으로 사료된다.

• KSBB Journal
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• 제26권2호
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• pp.100-106
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• 2011

Strain BCNU 5011 was isolated from forest soil samples collected in the Taebaek mountain in the Gangwon province, Korea. The biochemical, physiological and 16S rRNA sequence analysis strongly indicated that this isolate was most closely related to Paenibacillus polymyxa. A maximum production level of antimicrobial substances of Paenibacillus sp. BCNU 5011 was achieved under aerobic incubation at $30^{\circ}C$ for 3 days in SST broth.Paenibacillus sp. BCNU 5011 showed a broad spectrum of activity against Gram positive and Gram negative bacteria, including methicllinresistant Staphylococcus aureus (MRSA). Paenibacillus sp. BCNU 5011 was also shown to inhibit the growth of different potential human pathogenic bacteria and fungi in vitro. Peptide extract showed better antimicrobial activity than solvent extracts. But active antimicrobial compounds might be included in both peptide extract and solvent extracts. Further separation, purification and identification of active principles leads project to develop antimicrobial agents and anti-MRSA agents.

• Current Research on Agriculture and Life Sciences
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• 제32권3호
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• pp.119-124
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• 2014

Physalis alkekengi var. francheti Hort. is known as an insecticide and traditional remedy for liver related diseases. Therefore, this study investigated the chemopreventive effects of extracts and several solvent fractions (n-hexane, dichloromethane, n-butanol, water) of Physalis alkekengi var. francheti Hort. First, their cytotoxicity and NQO1 activity were measured using an MTT assay, plus a quinone reductase [NAD(P)H dehydrogenase (quinone); NAD(P)H: (quinone acceptor) oxidoreductase, EC 1.6.99.2]-inducing activity assay was performed using cultured murine hepatoma cells (Hepa1c1c7) and its mutant cells(BpRc1). The reduction of electrophilic quinones by NQO1 is an important detoxification pathway and major mechanism of chemoprevention. When compared with the other solvent soluble fractions with different polarities, the dichloromethane fraction of Physalis alkekengi var. francheti Hort. showed a higher NQO1-inducing activity that was also dose-dependent. Moreover, the dichloromethane fraction of Physalis alkekengi var. francheti Hort. induced ARE-luciferase activities in HepG2-C8 cells that were generated by transfecting the ARE-luciferase gene construct, suggesting the Nrf2-ARE-mediated induction of anti-oxidative enzymes. In conclusion, the dichloromethane-soluble fraction of Physalis alkekengi var. francheti Hort. showed a relatively strong induction of detoxifying enzymes, thereby meriting further study to identify the active components and evaluate their potential as cancer preventive agents.

• 한국수산과학회지
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• 제53권6호
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• pp.886-893
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• 2020

The seaweed Hizikia fusiformis is rich in protein, carbohydrates, vitamins, and minerals. This study investigated the antioxidant and physiological activities of H. fusiformis extracts prepared with 70% ethanol, 80% methanol, or distilled water. The extraction yields of these various solvent extracts were as follows: ethanol extract, 15.26%; methanol extract, 17.95%; and water extract, 45.62%. The methanol extract showed the highest total polyphenol content (24.06 mg GAE/g), but total flavonoid content was similar in all extracts. ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity was highest in the ethanol extract (IC50: 0.90 mg/mL), while the methanol extract exhibited the strongest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (IC50: 8.09 mg/mL), reducing power (EC50: 0.40 mg/mL), and ferric reducing antioxidant power (0.28 mM). By contrast, tyrosinase and α-glucosidase inhibitory activities were higher in the ethanol extract than in the other extracts. The high BACE1 (β-secretase) inhibitory activity was observed in the ethanol extract (IC50: 1.03 mg/mL). These results indicate that H. fusiformis ethanol extracts may be useful for their antioxidant and functional properties in food and pharmaceutical materials.