The purpose of this study is to investigate what factors make the relationships between Korean firms and their Canadian counterparts good or bad, particularly within the context of international trade. This study suggests that the factors affecting the quality of business relationship and relationship performance include relational norms, formalization, and market uncertainty. It also proposes that relational norms are determined by trust, relationship investment, and continuity experience. Data was collected through a mail survey of 412 Korean exporting firms which have transaction relationships with Canadian companies. Data strongly supports the research hypotheses. As hypothesized, the results of data analysis show that relational norms and formalization tend to enhance relationship quality and relationship performance. The impact of formalization is only moderate, however. In addition, we notice that relationship quality and relationship performance seem to decrease as market uncertainty increases. Data also supports the hypotheses regarding the determinants of relational norms. Trust, relationship investment, and continuity experience tend to induce the development of relational norms.

본 연구는 의료용 선형가속기 시설을 차폐하는 콘크리트에 대한 중성자 방사화 연구로써, 일반 콘크리트 와 저 방사화 콘크리트를 비교 분석하였다. 실험 방법은 MCNPX (Ver. 2.5.0)와 FISPACT-2010를 사용하여 모의실험을 진행하여, 광자선과 중성자선에 대한 차폐능을 산정하고 중성자 방사화 평가를 진행하였다. 그 결과 차폐능은 일반 콘크리트에서 20~50 ㎝ 효율적이였으며, 방사화 평가의 경우 저 방사화 콘크리트에서 방사능이 낮게 계산되었으나, 모두 자체처분허용 농도를 초과하지 않는 수준으로 산정되었다. 이를 종합적 으로 분석한 결과 일반 콘크리트를 사용하는 것이 효율적인 것으로 판단된다.

본 연구에서는 미숙과 복분자 추출물의 건강기능식품 기능성 원료 개발을 위하여 지표성분을 ellagic acid로 설정하였으며, HPLC 분석법의 유효성을 검증하였다. 또한 국내 재배종 미숙과 복분자인R. occidentalis와 중국 재배종 미숙과 복분자인 R. chingii의 ellagic acid 함량 차이와 시험법 적용을 통해 원료의 상호대체 및 혼용 가능성을 확인 하였다. 추출용매별 ellagic acid 함량을 분석한 결과, 5% 주정 추출물이 국내산과 중국산에서 각각 16.56 mg/g과 17.27mg/g으로 가장 높게 나타났으며 두 종간의 함량 차이가 없음을 확인하였다. 향 후 두 종간의 생리활성 비교 연구를 통해 생리활성물질인 ellagic acid 함량 유사성과 같이 두 종간의 생리활성 유사성 부분의 추가 검증 연구가 필요할 것으로 사료된다. 또한 본 연구에서의 분석법 검증은 특이성, 직선성, 정확성 및 정밀성을 확인하였으며 그 결과, 표준용액의 피크유지시간과 spectrum이 미숙과 복분자 5% 주정추출물과 일치하여 특이성을 확인 하였다. 검량선의 R2은 0.9999으로 높은 직선성을 보였으며, 검출한계 0.25 μg/mL, 정량한계는 0.77 μg/mL였다. 회수율은 97.54-101.01%의 범위로 나왔고, 일내분석과 일간분석에서 상대표준편차는 국내산이 각각 0.54-1.30%와 2.23-3.15%, 중국산이 각각 0.48-2.21%와 1.57-2.79%로 나왔다. 따라서 본 연구를 통하여 기존의 문헌에서 제시된 ellagic acid 분석법이 미숙과 복분자 5% 주정추출물에서의 지표성분 표준분석법으로 적합한 시험법임을 재검증하였고, 건강기능식품 기능성 원료로서 ellagic acid를 지표성분으로 설정하였을 경우 국내산 미숙과 복분자인R. occidentalis와 중국산 미숙과 복분자인R. chingii의 수급 여건에 따라 상호 대체가 가능한 근거가 될 수 있는 자료중 하나로 활용될 수 있을 것으로 판단된다.

Dendropanax morbifera Leveille (Araliaceae) is an endemic species growing in the south-western part of South Korea that has been used in folk medicine and health functional food. In this study, we investigated an extract of quercetin in Jeju D. morbifera by varying different parts (fruit, sprouts, leaves, sprigs, and branches), harvest times, and extraction solvents. In addition, we aimed to establish a simple and reliable HPLC/UV analytical method to determination of quercetin for the quality control and base line data of the Jeju D. morbifera extract as a health functional food ingredient. The analytical specificity was determined with retention time and photo diode array (PDA) spectrum by analyzing quercetin using HPLC and comparing the results to those of extracts. This analytical method for quercetin was validated for its limit of detection (LOD), limit of quantitation (LOQ), precision, and accuracy. A high linearity in the standard calibration curve was obtained, with a coefficient of determination (R2) of 0.9996. Also, the LOD and LOQ values were found to be 0.28 μg/mL and 0.85 μg/mL, respectively, and the recoveries of quantified compounds ranged from 97.91% to 104.10%. Furthermore, the relative standard deviation (RSD) values of data from the intra- and inter-day precision analyses were less than 1.36% and 3.65%, respectively. As a result, the highest quercetin content among the extracts of Jeju D. morbifera leaves was found to be 20.14 mg/g, which was extracted at harvest in May (cultivation period 10 years) with 60% EtOH. All in all, we believe that the results obtained would be helpful in the development of nutraceutics and natural medicines and for the quality control of D. morbifera.

본 연구는 원자력 발전소가 인접해 있는 부산지역 경찰관들의 원자력 사고와 방사능 테러에 대한 인식 과 대처 방안을 파악함으로써, 이와 관련한 정책 수립에 기초자료를 제공하고자 하였다. 부산광역시에 근 무하는 221명의 경찰을 대상으로 하였으며, 조직구성, 지휘능력, 여론운영 등으로 설문을 구성하여 재난대 응 인식도를 분석하였다. 그 결과, 성별 및 지휘계급에 따른 재난대응 인식은 큰 차이가 없는 것으로 나타 났다(p>.05). 연령의 경우 지휘능력에 대한 통계적 차이(p<.05)를 보였으며, 근무경력에 따른 지휘능력도 통 계적 차이(p<.05)를 나타냈다. 상관관계 분석 결과, 조직구성에 대한 인식과 지휘능력, 여론운영 3가지 항목 이 +0.5 이상으로 정적상관을 나타냈다(p<.01). 전반적으로 경찰 체제에 대해 긍정적인 것으로 나타났으며, 방사선사고 및 테러 발생 시 경찰의 업무를 잘 인식하고 있었다.

Background : Heat stress induced from high temperature are known to crucially affecting on physiological properties and yield in Cnidium officinale. Methods and Results : The effect of foliar application of mixture including a urea, ascorbic acid and calcium chloride on high temperature injury of Cnidium officinale. Photosynthesis and leaf temperature in Cnidium officinale were investigated after cultivating for 24 hours at 35℃. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and leaf temperature was analyzed by thermal image. Net photosyntheis rate, stomatal conductance and transpiration rate in mixture traetment were 2 times of higher than in control. Water use efficience was not different significantly. Leaf temperature was lower in mixture treatment (25.3℃) than in control (29.0℃). Conclusion : This result show that foliar application of urea, ascorbic acid and calcium chloride was reducing a high temperature injury through a improving photosynthetical capacity and decreasing leaf temperature of Cnidium officinale.

Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Cnidium officinal were investigated using growth chamber after cultivating for 24 hours under controlled condition. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate was highest in treatment of 25℃. Although transpiration rate was lowest, water use efficience was also in treatment of 25℃. Stomatal conductance was mainly influenced from ambient climatric factors such as vapor pressure deficit. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII), PIabs and the relative activities per reaction center such as ABS/RC, DIo/RC were not changed at air temperature. Therefore, elevated air temperatue during short term influence the dark reaction in photosystem through controlling a water use efficience and transpiration. Conclusion : This result show that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis in Cnidium officinale.

Background : Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae. Its roots have been utilized as a traditional medicine but the aerial parts (flower, flower stalk, leaf) were not used. In this paper, we aimed to determine the content of three compounds [aucubin, catalpol, and γ-aminobutyric acid (GABA)] in different organs of R. glutinosa. Methods and Results : The flower, flower stalk, leaf, and root of R. glutinosa were harvested in the end of August. The aucubin and catalpol were analyzed by LC/MS, whereas GABA was analyzed by GC/MS. The aucubin content was the highest in the leaf, while catalpol and GABA were the highest in the flower. The aucubin content of in the leaf was 1.43, 0.81, and 1.07 ㎎/g, respectively. The catalpol content of flower in Dakang, Tokang, and Suwon 9 was 41.06, 28.78 and 37.48 ㎎/g, respectively. The GABA content of flower in Dakang, Tokang, and Suwon 9 were 0.79, 0.76 and 0.65 ㎎/g, respectively. Conclusions : The contents of aucubin, catalpol, and GABA were higher in leaf and flower than that of root. This study provides the important information of R. glutinosa leaf and flower as a potential supplement.

Background : Ixeris genus has been used in traditional medicines as stomachics, sedatives, and diuretics. Ixeris dentata var albiflora is a kind of perennial herbaceous plant and one of the plants of the genus Ixeris (Asteraceae). It is well-known for edible wild vegetable in Korea, China, Japan, and Mongolia. Specially, Korean has its root and young leaf with appetizing vegetable due to bitter taste. Methods and Results : We isolated 8 genes that are involved in carotenoid biosynthesis using the Illumina/Solexa HiSeq2000 platform. In this study, a full-length cDNA clone encoding phytoene synthase (IdPSY), phytoene desaturase (IdPDS), ξ-carotene desaturase (IdZDS), lycopene β-cyclase (IdLCYB), and zeaxanthin epoxidase (IdZEP) and partial-length cDNA clones encoding lycopene ε-cyclase (IdLCYE), ε-ring carotene hydroxylase (IdCHXE), and β-ring carotene hydroxylase (IdCHXB2) were identified in I. dentata. The theoretical molecular weight (MW) and isoelectric point values of 8 genes were investigated. Sequence analyses revealed that these proteins shared high identity and conserved domains with their orthologous genes. IdPSY, IdPDS, IdZDS, IdLCYB, IdCHXB2, and IdZEP were constitutively expressed in the roots, stems, leaves, and flowers of I. dentata. Conclusion : Our study on the biosynthesis of carotenoids in I. dentata will provide basic data for elucidating the contribution of carotenoids to the considerable medicinal properties of I. dentata.

Background : Curcuma longa L., in the family Zingiberaceae, is distributed in tropical and/or sub-tropical regions mainly in India and China. This species is commonly called turmeric, powder is used as medicinal herbs and/or flavor enhancer. It has been cultivated in southern region mainly Jindo. However, it might be possible to extend cultivation regions due to rise in average temperature. In order to select superior lines based on agronomic characteristics, we analyzed multivariate and estimated selection effects from C. longa germplasm. Methods and Results : The C. longa germplasm were cultivated in an experimental field located in Eumseong, NIHHS, RDA. The harvested roots were investigated in agronomic characteristics included in yield and then considered its relationship among the 9 germplasm by multivariate analysis method. Results from principal component analysis (PCoA) showed that it represented 70.00% and 80.44% accumulated explanation from four and five principal compounds (PC). PCoA was conducted from 9 agronomic characteristics and then correlation coefficient has been showed by analysis between each main component value and agronomic characteristics. Value of the first PC was 2.25, 24.96% explanation of total dispersion, plant height, number of rootlet and weight of rootlet were correlated with a somewhat higher level as 0.41, 0.43 and 0.52. Value of the fifth PC was 0.94, 10.43% explanation of total dispersion, the number of shoots was correlated with a higher level as 0.87. Selection effects with outstanding candidate lines including higher lines were estimated at 126.13% in yield. Conclusion : These data on multivariate based on agronomic characteristics will be give us invaluable breeding information by selection of superior lines.

Background : Cylindrocarpon root rot, caused by Cylindrocarpon destructans and Fusarium solani, is a major disease which lead to replanting failure in ginseng garden. Chlamydospores of C. destructans, generated by poor environmental condition, can survived more than ten years in soil without host plant, ginseng. Density of soil pathogens gradually decreased as the progress of time since ginseng was harvested. Methods and Results : Soil chemical properties was analyzed from soil samples of 43 regions in farmer’s ginseng garden to study the variation of content and the correlation among inorganic contents. Soil samples of 24 regions was also analyzed to study correlation between progressed-year after ginseng harvest and soil chemical properties. Variation of soil chemical properties in descending order was Fe, Zn, P2O4, NO3, Mn. The content of Fe and Zn were great variation among inorganic chemicals of soil of farmer’s field. Electrical conductivity to induce physiological demage in excessive concentration showed highly significant positive correlation with the content of NO3 and K. As the progress of year after ginseng harvest, the content of organic matter and zinc was increased, while pH and Na were decreased in farmer’s field to cultivate ginseng. There were highly significant positive correlation between the progress of year after ginseng harvest and zinc content in farmer’s field to cultivate ginseng. Ratio of root rot of 2-year-old ginseng showed significant positive correlation with K content, and negative correlation in experimental field cultured by six rotation crops for one year. Conclusion : Root rot by soil pathogens was closely related with the content of potassium and zinc in soil chemical properties.

Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

Hepatocytes and hepatic progenitors derived from human ES cells may be a useful source for clinical application. Therefore, identification and purification of these cell types would be following important issues. There are very few candidate surface markers that can be used to identify and purify hepatic progenitor cells. In addition, indocyanine-green can be uptaken by mature hepatocytes, but cannot be applied for fluorescence activated cell sorting (FACS) due to its long emission wavelength. In the present study, we tested EpCAM as a potential marker for magnetic-activated cell sorting (MACS) of hepatic progenitors and also modified indocyanine-green into fluorescent indomonocarbocyanine for FACS-mediated sorting of mature hepatocytes after differentiation of human ES cells. Hepatic progenitor cells were sorted by MACS after incubation with anti-human EpCAM antibodies. After the final differentiation, the differentiated cells and mouse primary hepatocytes (control group) were incubated with indomonocarbocyanine and were sorted by FACS. MACS and immunocytochemistry data showed that approximately 45% of differentiated cells were EpCAM-positive cells. EpCAM-positive cells expressed α-fetoprotein, FOXa2, HnF4a, and CK18. Differentiation efficiency into albumin-positive cells was significantly higher in EpCAM-positive cells, compared to EpCAM-negative cells. Importantly, indomonocarbocyanine successfully stained cells that expressed ALB. Furthermore, FACS analysis data showed that the purity of hepatocytes that expressed albumin was significantly increased after purification of indomonocarbocyanine-positive cells. Our data demonstrated that human ES cell-derived hepatic progenitors can be efficiently isolated by MACS using EpCAM antibody. In addition, we also showed that indomonocarbocyanine can be successfully used to identify and purify mature hepatocytes using FACS.

Highly homogeneous and functional stem cell-derived hepatocyte-like cells (HLCs) are considered a promising option in the treatment of liver disease and the development of effective in vitro toxicity screening tool. However, the purity of cells and expression and/or activity of drug metabolizing enzymes in stem cell-derived HLCs are usually too low to be useful for clinical or in vitro applications. Here, we describe a highly optimized differentiation protocol, which produces more than 90% albumin-positive HLCs with no purification process. In addition, we show that hepatic enzyme gene expressions and activities were significantly improved by generating three-dimensional (3D) spheroidal aggregate of HLCs. The 3D differentiation method increased expressions of nuclear receptors that regulate the proper expression of key hepatic enzymes. Furthermore, a significantly increased hepatic functions such as albumin and urea secretion were observed in 3D hepatic spheroids and HLCs in the spheroid exhibited morphological and ultrastructural features of normal hepatocytes. Importantly, we show that repeated exposures to xenobiotics facilitated the functional maturation of HLC, as confirmed by increased expression of genes for drug metabolizing enzymes and transcription factors. In conclusion, the 3D culture system with repeated exposures to xenobiotics may be a new strategy for enhancing hepatic maturation of stem cell-derived HLCs as a cell source for in vitro high-throughput hepatotoxicity models.

Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs