• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.281-281
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• 2010

Very low refractive index (<1.4) materials have been proved to be the key factor improving the performance of various optical components, such as reflectors, filters, photonic crystals, LEDs, and solar cell. Highly porous SiO2 are logically designed for ultralow refractive index materials because of the direct relation between porosity and index of refraction. Among them, ordered macroporous SiO2 is of potential material since their theoretically low refractive index ~1.10. However, in the conventional synthesis of ordered macroporous SiO2, the time required for the crystallization of organic nanoparticles, such as polystyrene (PS), from colloidal solution into well ordered template is typical long (several days for 1 cm substrate) due to the low interaction between particles and particle - substrate. In this study, polystyrene - polyacrylic acid (PS-AA) nanoparticles synthesized by miniemulsion polymerization method have hydrophilic polyacrylic acid tails on the surface of particles which increase the interaction between particle and with substrate giving rise to the formation of PS-AA film by simply spin - coating method. Less ordered with controlled thickness films of PS-AA on silicon wafer were successfully fabricated by changing the spinning speed or concentration of colloidal solution, as confirmed by FE-SEM. Based on these template films, a series of macroporous SiO2 films whose thicknesses varied from 300nm to ~1000nm were fabricated either by conventional sol - gel infiltration or gas phase deposition followed by thermal removal of organic template. Formations of SiO2 films consist of interconnected air balls with size ~100 nm were confirmed by FE-SEM and TEM. These highly porous SiO2 show very low refractive indices (<1.18) over a wide range of wavelength (from 200 to 1000nm) as shown by SE measurement. Refraction indices of SiO2 films at 633nm reported here are of ~1.10 which, to our best knowledge, are among the lowest values having been announced.

• Food Science and Biotechnology
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• 제14권1호
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• pp.58-63
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• 2005

Ethyl acetate-soluble neutral fraction of hot water extracts from the aerial parts of Angelica keiskei showed a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Six antioxidative compounds were purified and isolated by various chromatographic procedures. Based on the analyses of FAB-MS and NMR, the isolated compounds were structurally elucidated as luteolin 7-O-${\beta}$-D-glucopyranoside (1), quercetin 3-O-${\beta}$-D-galactopyranoside (2), quercetin 3-O-${\beta}$-D-glucopyranoside (3), quercetin 3-O-${\alpha}$-D-arabinopyranoside (4), kaempferol 3-O-${\alpha}$-D-arabinopyranoside (5), and luteolin 7-O-rutinoside (6). The glycosides of flavonols and luteolin showed DPPH radical-scavenging activity. One molecule of 2, 3, 4, 6, 1, and 5 scavenged 4.2, 4.2, 4.1, 2.5, 2.2, and 1.4 molecules of DPPH radical, respectively.

• Fibers and Polymers
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• 제6권1호
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• pp.28-34
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• 2005

The purpose of the research was to examine the effect of three different levels of enzyme treatment on the physical characteristics and the end-use suitability of the lyocell fabrics made with four different types of commercial wood pulp. The appropriate enzyme concentration for obtaining an optimum as well as consistent physical characteristics and fabric hand trait was 3 g/l for the concentration levels tested in the present investigation. Weight loss was more affected by higher enzyme con­centration than other physical properties. H2 was least affected by enzyme treatment for all three physical properties and fab­ric hand. 5 g/l concentration exhibited little difference from 3 g/l in the physical characteristics, whereas the KES-FB values indicated a significant loss of fabric hand in most PHV s with the 5 g/l concentration level. Among different garment parame­ters, all four fabric types were relatively inappropriate for the men's slacks (MS) fabric due to the lower hand value of koshi required by the MS parameter. However, despite the relatively low koshi values, high fukurami values required for men's dress shirt (MWDS) resulted in the highest THV among the four garment parmeters. The four fabric types, which represent the usage of four different wood pulps, in general seem to exhibit a higher applicability to women's winter thin dress (WWTD) than women's winter suit (WWS) garment parameter.

• 약학회지
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• 제53권3호
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• pp.130-137
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• 2009

In this study, isolation of antioxidative compounds was performed for development of anti-oxidizing agent. $CHCl_3$, $H_2O$, 30%, 60% MeOH, MeOH fractions were examined antioxidative activity by DPPH, test of inhibition on NO production. It was revealed that 30%, 60% MeOH and $CHCl_3$ fractions had significant antioxidative activity. In 30% MeOH and 60% MeOH, $CHCl_3$ fraction, six compounds were isolated and elucidated as adenosine(I), guanosine(II), peucedanol 7-O-$\beta$-D-apiofuranosyl(1$\rightarrow$6)-$\beta$-glucopyranoside(III), peucedanol 7-O-$\beta$-D-glucopyranoside(IV), peucedanol(V) and scopoletin(VI) by physicochemical data and spectroscopic methods. (Negative FAB-MS, $^{1}H-NMR$, $^{13}C-NMR$). The results from antioxidative activity screening for the each compound showed that compound IV was relatively superior antioxidant ability. In anti-inflammatory activation assay, compound III, IV, VI had concentration-dependent-activity and compound IV had superior anti-inflammatory ability. These results suggest that Peucedani Radix might be developed as a potent anti-oxidative, anti-inflammatory agents and ingredients for related functional foods.

• 대한임상독성학회지
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• 제5권2호
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• pp.106-111
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• 2007

Purpose: Inadequate hospital stocking and unavailability of essential antidotes is a worldwide problem. The purpose of this study was to determine the adequacy of antidote stocks in Korean hospitals based on a modified version of US antidote stocking guidelines. Methods: Both written and telephone surveys to collect information on hospital demographics and antidote stocking were given to the emergency departments or hospital pharmacies of 117 hospitals with emergency medical centers. The twenty antidotes included in the survey were taken from year 2000 US antidote stocking guidelines, except for activated charcoal and black widow spider antivenin. Antidote stocks were compared by hospital size, geographic location, and type of emergency medical center. Results: Complete responses were received from all hospitals. A mean of $12.4{\pm}2.9$ antidotes were adequately stocked per hospital. All hospitals stocked atropine, $CaCl_2$ naloxone, and sodium bicarbonate. However, digoxin Fab fragment (16%), cyanide kits (15%), EDTA (10%), BAL (9%), and fomepizole (1%) were not uniformly stocked. Large and teaching hospitals were significantly more likely to stock greater numbers of antidotes. Conclusions: Korean hospitals as a group do not have adequate antidote stocks. Korean stocking guidelines and an antidote management system are recommended in order to correct these deficiencies.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.342-346
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• 2008

Aurintricarboxylic acid (ATA) prevents apoptosis in a wide range of cell types, including PC12 cells. ATA is known to increase the phosphorylation level of IGF-1 receptor (IGF-1R) and downstream signaling proteins. ATA can translocate across the plasma membrane of PC12 cells and inhibit protein tyrosine phosphatases (PTPs) and, therefore, it is not clear whether ATA exerted its antiapoptotic effect through activation of IGF-1R or by inhibition of cytosolic PTPs. When PC12 cells, deprived of serum, were treated with Fab fragment of anti-IGF-1R antibody to prevent the binding of ATA to the extracellular domain of IGF-1R, ATA was found to penetrate into the cytosolic space of the cells. Under these conditions, the survival-promoting effects of ATA were abolished, and the increase of phosphorylation and characteristic cleavage of IGF-1R were not observed. These results indicate that the antiapoptotic effect of ATA in PC12 cells is due to the binding of ATA to the extracellular domain of IGF-1R and subsequent activation of the IGF-1R, not inhibition of cytosolic PTP(s).

• Journal of Applied Biological Chemistry
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• 제59권4호
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• pp.313-316
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• 2016

꽃송이 버섯(S. crispa)을 80 % MeOH 수용액으로 추출하고, 추출물을 EtOAc, n-butyl alcohol 및 물 분획으로 나누었다. EtOAc 분획과 n-BuOH 분획에 대해 $SiO_2$ 및 ODS column chromatography를 반복적으로 실시하여 2종의 ergosterol peroxide를 분리, 정제하였다. infrared spectrometry, nuclear magnetic resonance 및 FAB-MS data를 해석, 화합물 1과 2를 ergosterol peroxide와 3-O-${\beta}$-D-glucopyranosyl ergosterol peroxide로 각각 구조동정 하였다. 두 화합물 모두 꽃송이 버섯으로부터는 이번 실험에서 처음으로 분리되었다.

• 한국식품영양과학회지
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• 제30권4호
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• pp.732-738
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• 2001

두충잎에서 인간대장암에세포 HCT-116에 세포증식 억제효과를 나타내는 성분을 silica gel column chromatography TLC로 분리하고 HPLC로 정제한 다음 UV-visual spectro-photometer에 의한 흡수 spectra 특성 HPLC에 의한 retention time과 분리패턴 및 FAB/MS로 분자량을 잠정적으로 동정한 결과 TLC 상에서 분리된 Rf 0.19 band 의 화합물은 chlorophyll a에서 $Mg^{2+}$이 제거된 pheophytin a로 Rf 0.25 band의 화합물은 pyropheophytin a로 확인되었다. 동정된 화합물들의 암세포 억제작용을 확인하기 위해 두충잎의 petroleum ether extract column chromatography로 분리한 분획물 및 TLC에서 분리된 각 band들의 cytotoxic activity을 in vitro에서 HCT-116 cancer cell을 사용하여 측정한 결과 모든 시료에서 암세포 증식억제 현상을 보였으며 특히 Rf 0.19와 Rf 0.25 band에서 분리된 화합물들에서 강하게 나타났다. 이 결과로 볼 때 두충잎에서 분리한 클로로필 유도체는 인간대장암세포인 HCT-116 cell에 대해 강한 항암작용이 있는 것으로 생각된다.

• 한국자원식물학회지
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• 제22권1호
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• pp.26-30
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• 2009

본 연구는 속리산국립공원 내 쌍곡계곡에 분포하는 식물상을 조사하기 위해 수행되었고 조사기간은 2006년 3월부터 2007년 6월까지 조사하였다. 식물상을 조사한 결과, 88과 242속 342종 52변종 7품종 등 총 401분류군이 확인되었다. 한국특산식물은 개비자나무, 키버들, 개족도리, 할미밀망, 민산초나무, 청괴불나무, 병꽃나무, 분취 등 총 8분류군이 조사되었다. 환경부 지정 멸종위기식물은 망개나무 등 1분류군이며, 산림청 지정 희귀식물은 개족도리, 고란초, 망개나무, 백작약, 태백제비꽃, 꼬리진달래, 말나리 등 7분류군이 조사되었다. 이들의 보전을 위해서는 향후 희귀식물에 대한 구체적인 보전방안과 번식방법 등이 논의되어야 할 것으로 판단된다. 자원식물은 관상용 식물 220분류군, 식용 식물 239분류군, 약용 식물 281분류군, 기타용 식물 206분류군으로 나타났다. 귀화식물은 오리새, 소리쟁이, 취명아주, 아까시나무, 붉은토끼풀, 토끼풀, 큰달맞이꽃, 비짜루국화, 붉은서나물, 개망초, 망초, 뚱딴지, 서양민들레 등 13분류군이 관찰되었으며, 귀화율은 약 3.24%, 자연파괴도는 약 4.53%로 나타났다.

• 대한전자공학회논문지SD
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• 제37권12호
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• pp.79-90
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• 2000

본 논문에서는 고성능 수퍼스칼라 마이크로프로세서에 적합하고, IEEE 754 표준을 준수하는 고성능 부동 소수점 유닛의 구조를 설계한다. 부동 소수점 AU에서는 비정규화 수 처리를 모두 하드웨어적으로 지원하면서 추가적인 지연 시간이 생기지 않도록 점진적 언더플로우 예측 기법을 제안 구현한다. 부동 소수점 제산/제곱근기는 기존의 고정적인 길이의 몫을 구하는 방식과 달리 매 사이클마다 가변적인 길이의 몫을 구하는 구조를 채택하여 성능과 설계 복잡도 면에서 SRT 알고리즘에 의한 구현 보다 우수하도록 설계한다. 또한, 수퍼스칼라 마이크로프로세서에 이식이 용이하도록 익셉션 예측 기법을 세분화하여 적용하며, 제산 연산에서의 익셉션 예측에 필요한 스톨사이클을 제거하도록 한다. 설계된 부동 소수점 AU와 제산/제곱근기는 부동 소수점 유닛의 구성요소인 명령어 디코더, 레지스터 파일, 메모리 모델, 승산기 등과 통합되어 기능과 성능을 검증하였다.