• Applied Science and Convergence Technology
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• 제23권5호
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• pp.201-210
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• 2014

The influence of electron irradiation and hydrogen adsorption on the electronic structure of the $SrTiO_3$ (001) surface was investigated by ultraviolet photoemission spectroscopy (UPS). Upon electron irradiation of the surface, UPS revealed an electronic state within the band gap (in-gap state: IGS) with the surface kept at $1{\times}1$. This is considered to originate from oxygen vacancies at the topmost surface formed by electron-stimulated desorption of oxygen. Electron irradiation also caused a downward shift of the valence band maximum indicating downward band-bending and formation of a conductive layer on the surface. With oxygen dosage on the electron-irradiated surface, on the other hand, the IGS intensity was decreased along with upward band-bending, which points to disappearance of the conductive layer. The results indicate that electron irradiation and oxygen dosage allow us to control the surface electronic structure between semiconducting (nearly-vacancy free: NVF) and metallic (oxygen de cient: OD) regimes by changing the density of the oxygen vacancy. When the NVF surface was exposed to atomic hydrogen, in-gap states were induced along with downward band bending. The hydrogen saturation coverage was evaluated to be $3.1{\pm}0.8{\times}10^{14}cm^{-2}$ with nuclear reaction analysis. From the IGS intensity and H coverage, we argue that H is positively charged as $H^{{\sim}0:3+}$ on the NVF surface. On the OD surface, on the other hand, the IGS intensity due to oxygen vacancies was found to decrease to half the initial value with molecular hydrogen dosage. H is expected to be negatively charged as $H^-$ on the OD surface by occupying the oxygen vacancy site.

• 보건의료산업학회지
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• 제13권1호
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• pp.15-30
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• 2019

Objectives: This study aimed to analyze people's accessibility to medical institutions providing national gastric cancer screening services in Gangwon-do using a geographic information system(GIS). Methods: To assess the spatial accessibility, network analysis was applied. Two types of network analysis-Service area analysis and origin-destination cost matrix(OD-cost matrix)-were applied to create network dataset. Results: The results of the analysis of the service area revealed that it took more than 60 minutes each to reach tertiary hospitals and general hospitals from 74.4% and 9.6% of Gangwon-do areas, respectively. Similarly, it took more than 60 minutes each to reach hospitals and clinics from 4.2% and 3.4% of Gangwon-do areas, respectively. The results of the OD-cost revealed that there were large regional variations in distance and time taken to reach the medical institutions. Conclusions: there were regional variations of spatial accessibility between Si and Gun in Gangwon-do.

• 동아시아식생활학회지
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• 제21권1호
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• pp.60-67
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• 2011

울릉도농업 특산물인단호박, 삼나물및 부지깽이의항산화능의 조사와 이를 이용하여 제조한 엿의 품질 특성을 조사하였다. 삼나물의 총 폴리페놀 함량(dry basis as raw plant)은 물 추출물에서는 2.95 mg%이었으나 에탄올 추출물에서는 3.57 mg%였으며, 부지깽이는 물 추출물과 에탄올 추출물에서 2.75~2.77 mg%로 뚜렷한 차이를 보이지 않았다. 단호박에서는 물 추출물과 에탄올 추출물이 큰 차이가 없이 0.32 mg%이었다. 0.01%에서의 환원력은 삼나물 추출물과 부지깽이 추출물이 1.62~1.91($OD_{700}$)로 단호박의 0.02~0.03($OD_{700}$)에 비하여높았다. 삼나물과 부지깽이의 물 또는 에탄올 추출물(0.01% solution)의 전자공여능은74.91~79.21%로단호박에탄올추출물의 14.99%보다 높았으며 단호박 물 추출물의 전자공여능은 3.79%이었다. 호박엿을 제조하기 위한 호박과 물엿의 적정 비율은 색상과 종합적인 기호도로 평가한 결과 25:75(w/w)이었다. 단호박 엿에 삼나물 에탄올 추출물의 적정 첨가 비율은 0.4%이었으며, 부지깽이 에탄올 추출물은 3% 첨가가 우수하였다. 삼나물 및 부지깽이 분말의 적정 첨가 비율은 각각 0.5~1.0%(w/w) 및 1%(w/w) 범위였다.

• 약학회지
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• 제43권6호
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• pp.793-797
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• 1999

Salmonella typhi Ty21a is an attenuated strain of S. typhimurium and used for oral typhoid vaccine. In an attempt to increase the stability of Ty21a manufacturing typhoid vaccine, we studied about the stability of freeze-dried Th21a including additives at various temperature conditions. In order to investigate the freeze-drying rate of Ty21a according to various absorbance, we lyophilized Ty21a by using 8% sucrose as a stabilizer. The optimal freeze-drying rate of Ty21a was appeared when OD (optical density) value of the growth was between 2.5 and 3.0. To investigate the stability of Ty21a at various temperature, the viability was measured after storaging the freeze-dried Ty21a at the room temperature, cold and freezing condition for 1 week. The viability of Ty21a in cold and freezing storage condition was 5 times more stable than in room temperature. To search the most stable additives for the freeze-dried Ty21a, the viability of Ty21a including additives at the various storage condition was estimated. Mannitol and loctose were the most stable additives. Theses results suggest that the OD value of Ty21a growth, low temperature, mannitol and lactose are important factors for the optimal freeze-drying rate, the stable storage and the most stable additives, respectively.

• 한국임상수의학회지
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• 제19권1호
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• pp.86-91
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• 2002

The inhibitory effect of pooled canine serum on the growth of ten strains of Malassezia pachydermatis in vitro was investigated. Studies were also carried out to observe the effect of different concentrations of unsaturated bovine transferrin on Malassezia growth in vitro. Ten strains of Malassezia pachygedrmatis in normal canine serum (11.1%, 44.4%) were found to significantly inhibit the growth (p<0.0005) not only in a dose dependent but also in a time dependent manner. The same strains of yeast treated with 1, 2, 4 and 8 times the normal value of serum transferrin (3.0 mg/ml, 6.0 mg/ml, 12.0 mg/ml, 24.0 mg/fl), were shown to have significantly lower OD readings (p<0.05) when compared to yeast treated in lower concentrations of transferrin (1.5 mg/ml). The optical density (OD) of the ten strains of yeast were significantly lower (p<0.005) when treated with various concentrations of transferrin than with the saline control except at 72 hours post incubation. These results indicate that serum has inhibitory effects on Malassezia pachydermatis growth in vitro, and transfferin is one of the components that contribute towards this inhibitory role. The inhibitions are dose and time dependent.

• 미생물학회지
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• 제53권2호
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• pp.79-82
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• 2017

먹물버섯 Coprinus comatus를 yeast extract peptone dextrose 액체배지에서 배양하고 laccase의 생성 분비를 확인하였다. 이 때 분비된 laccase를 이온교환수지 방법과 전기영동 분획수집방법으로 순수하게 정제하였다. 정제된 효소단백질의 분자량은 SDS-PAGE로 분석하였을 때 약 67 kDa으로 나타났고 최적산도는 pH 4.3, 최적온도는 $25^{\circ}C$로 확인되었다. 기질 o-tolidine에 대한 Km 값은 0.45 mM, Vmax 값은 0.0132 OD/min/unit로 나타났다. 정제된 laccase를 사용하여 염료 RBBR과 Poly R-478의 탈색을 분석한 결과 배양 12시간 후에 RBBR은 49.3% 탈색되었고 poly R-478은 41.6% 탈색되었다.

• 대한수의학회지
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• 제43권2호
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• pp.263-270
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• 2003

The objective of the present study was to investigate the use of fluid released from muscle samples as an alternative to serum for ELISA to detect classical swine fever(CSF) virus antibodies in slaughter pigs. The optimal correspondence between serum 1:20 OD values and muscle fluid OD values was achieved at a muscle fluid dilution of 1:2. Significant correlation was found between serum and neck muscle ELISA ($r_s=0.880$, p<0.0001, ${\kappa}=0.82$; specificity of 97.0% and sensitivity 90.6%). The semimembranous muscle showed similar correlation in CSF ELISA($r_s=0.877$, p<0.0001, ${\kappa}=0.75$; specificity of 94.1% and sensitivity 89.1%). High correlation was obtained between serum and mesenteric lymph node in the CSF ELISA ($r_s=0.937$, p<0.0001, ${\kappa}=0.87$; specificity of 97.1% and sensitivity 93.0%). Measmement agreement between serum ELISA and muscle fluid ELISA was calculated and expressed as limits of agreement. The correspondence of ELISA of serum and muscle fluid indicated limits of agreement. Above 95% of all muscle fluid values were distributed within this limits of agreement. Among the samples used for ELISA for detecting CSFV antibodies, mesenteric lymph node had the most correlation and agreement with serum ELISA. F-test for comparison of variances showed no significant difference between the serum and muscle fluid. In conclusion, muscle fluid is a useful postmortem alternative to serum to detect CSFV antibodies.

• 방송공학회논문지
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• 제6권3호
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• pp.205-214
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• 2001

본 논문에서는 IP 망을 통한 MP4 파일 스트리밍 시스템을 소개한다. 사용자는 제안된 스트리밍 시스템을 이용하여 IF망을 통해 서버측의 MF4 컨텐츠를 엑세스할 수 있으며, 스트리밍되는 컨텐츠와 상호 작용도 가능하다. MP4 파일 형식은 MPEG-4 미디어 정보를 저장할 수 있도록 설계되었으며, 객체 지향적 구조를 이루고 있다 본 논문에서 제시한 스트리밍 서버 시스템은 GUL, Session Manager, Splitter, SL Packetizer; Transmitter 등으로 구성되어 있으며, 클라이언트 시스템은 MPEG-4 참조 소프트웨어인 IMI-2D 플레이어를 기반으로 구현되었다. 또한 본 스트리밍 시스템은 실시간 전송이 필요한 미디어 데이터와 QoS 관리를 위해 RTP와 RTCP를 각각 사용하도록 설계되었으며, 초기객체기술자(IOD), 객체기술자(OD), BIFS와 같은, 스트리밍을 위해서 반드시 전송되어져야 할 데이터와 정지영상 및 텍스트 등과 같이 하나의 패킷으로 전송이 완료되는 미디어 데이터를 위해서는 TCP를 사용하도록 설계되었다.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.243-253
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• 2000

The purpose of this in vitro study was to evaluate dentin bonding by two different dentin bonding systems(DBS) using acetone based primer or adhesive [All Bond 2(AB2), One Step(OS)] when they were applied by wet or dry bonding technique. Morphology of resin-dentin interface and hybrid layer thickness(HLT) were investigated using Confocal Laser Scanning Microscope(CLSM) and compared to shear bond strength(SBS). 72 extracted sound human molars were randomly divided into 4 groups of 18 teeth each - Group 1.(AW); AB2 by wet bonding. Group 2(AD); AB2 by dry bonding. Group 3.(OW); OS by wet bonding, Group 4.(OD); OS by dry bonding. In 6 teeth of each group, notch-shaped class V cavities(depth 2mm) were prepared on buccal and lingual surface at the cementoenamel juction(12 cavities per group). To obtain color contrast in CLSM observation, bonding resins of each DBS were mixed with rhodamine B and primer of AB2 was mixed with sodium fluorescein. Prepared teeth of each group were treated with AB2, OS, respectively according to the manufacturer's instructions except for dentin surface moisture treatment after acid etching. In group 1 and 3, after acid etching, excess water was removed with wet tissue(Kimwipes), leaving consistently shiny, visibly hydrated dentin surface. In group 2 and 4, dentin surface was dried for 10 seconds at 1 inch distance. The treated teeth were then packed with composite resin(${\AE}$litefil) and light-cured. 12 microscopic samples($60{\sim}80{\mu}m$ thickness) of each group were obtained after longitudinal section and grinding(Exakt cutting and grinding system). Morphological investigation of resin-dentin interface and HLT measurement using CLSM were done. For measurement of SBS, remaining 12 teeth of each group were flattened occlusally to remove all enamel and grinded to 500 grit SiC(Pedemet Specimen Preparation Equipment). After applying DBS on the exposed dentin surface, composite resin was applied in the shape of cylinder, which has 5mm diameter, 1.5mm thickness, and light cured. SBS was measured using Instron with a crosshead speed of 0.5mm/min. It was concluded as follows, 1. HLT of AW(mean: $2.59{\mu}m$) was thicker than any other group, and followed by AD, OW, OD in descending order(mean; 2.37, 2.28, $1.92{\mu}m$). Only OD had statistically significant differences(p<0.05) to AW and AD. 2. There were intimate contact of resin and dentin at the interface in wet bonding groups, but gaps or irregular interfaces were observed in dry bonding groups. 3. The length, diameter, density of resin tags were various even in the same group without significant differences between groups and lots of adhesive lateral branches were observed. 4. There were no statistically significant difference of SBS between AB2 and OS, but SBS of wet bonding groups were significantly higher(p<0.05) than dry bonding groups. 5. There were no consistent relationships between HLT and SBS.

• 미생물학회지
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• 제47권2호
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• pp.143-150
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• 2011

기능성이 밝혀져 있는 자색고구마를 첨가하여 기호성과 영양뿐만 아니라 인체에 유익한 기능성 동치미 냉면육수 개발을 위한 연구를 수행하였다. 자색고구마를 첨가한 동치미 냉면육수 발효 과정에서 젖산균, pH, 산도, 유기산, 수용성 phenolics, anthocyanin, 및 항산화 활성 변화를 조사하였다. 특히, 자색고구마를 첨가한 경우 발효종기(72시간)에 수용성 phenolics 및 anthocyanins 함량은 각각 1.26 g/L 및 8.59 g/L로 대조실험과 비교하여 각각 5배 및 34배 높았다. DPPH 라디칼 소거 활성 96.80%, $ABTs^{+{\cdot}}$ 라디칼 소거활성 100.82%, 환원력 7.77 ($OD_{700}$), FRAP 6.89 ($OD_{593}$)로 대조실험과 비교하여 각각 4배, 1.2배, 2배 및 3.6배 높은 항산화 활성을 나타내었다. 이상의 결과로부터 동치미 냉면육수의 항산화 활성은 자색고구마의 수용성 phenolics와 anthocyanins과 밀접한 관련이 있는 것으로 판단되었으며, 항산화 활성이 증가된 기능성 동치미 냉면육수 제조가 가능하였다.