검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 24

        1.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bangladeshi medicinal plants (BMP) have a history of traditional use in treating chronic inflammatory diseases, but a BMP bark’s antioxidant and anti-inflammatory effects remain largely unexplored. This study assessed methanolic extracts’ antioxidant and anti-inflammatory properties from the bark of 15 medicinal plant species native to Bangladesh. The methanol extracts of BMP bark were evaluated for their total antioxidant activity and ability to counteract inflammation induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages. Among the 15 bark extracts from BMP, Albizia odoratissima (A. odoratissima), Engelhardia spicata (E. spicata), and Shorea robusta (S. robusta) showed the highest total phenolic contents and total antioxidant capacity by effectively scavenging free radicals. In particular, these three bark extracts significantly reduced the mRNA expression of LPS-induced inflammatory cytokines and enzymes inducible by inflammation in macrophages. Also, the mRNA expression of NADPH oxidase 2 was significantly suppressed by the three bark extracts in LPS-induced RAW 264.7 macrophages. These results suggest that out of the 15 bark extracts obtained from medicinal plants in Bangladesh, the extracts from A. odoratissima, E. spicata, and S. robusta exhibit substantial total antioxidant capacity by efficiently scavenging free radicals and also inhibit LPS-induced inflammation in macrophages.
        4,000원
        2.
        2023.11 구독 인증기관·개인회원 무료
        KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.
        3.
        2023.11 구독 인증기관·개인회원 무료
        The effect of various physicochemical processes, such as seawater intrusion, on the performance of the engineered barrier should be closely analyzed to precisely assess the safety of high-level radioactive waste repository. In order to evaluate the impact of such processes on the performance of the engineered barrier, a thermal-hydrological-chemical model was developed by using COMSOL Multiphysics and PHREEQC. The coupling of two software was achieved through the application of a sequential non-iterative approach. Model verification was executed through a comparative analysis between the outcomes derived from the developed model and those obtained in prior investigations. Two data were in a good agreement, demonstrating the model is capable of simulating aqueous speciation, adsorption, precipitation, and dissolution. Using the developed model, the geochemical evolution of bentonite buffer under a general condition was simulated as a base case. The model domain consists of 0.5 m of bentonite and 49.5 m of granite. The uraninite (UO2) was assigned at the canister-bentonite interface as the potential source of uranium. Assuming the lifetime of canister as 1,000 years, the porewater mixing without uranium leakage was simulated for 1,000 years. After then, the uranium leakage through the dissolution of uraninite was initiated and simulated for additional 1,000 years. In the base case model, where the porewater mixing between the bentonite and granite was the only considered process, the gypsum tended to dissolve throughout the bentonite, while it precipitated in the vicinity of bentonite-granite boundary. However, the precipitation and dissolution of gypsum only showed a limited effect on the performance of the bentonite. Due to the low solubility of uraninite in the reduced environment, only infinitesimal amounts of uranium dissolved and transported through the bentonite. Additional cases considering various environmental processes, such as seawater or cement porewater intrusion, will be further investigated.
        4.
        2019.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the summer season, natural ventilation is commonly used to reduce the inside air temperature of greenhouse when it rises above the optimal level. The greenhouse shape, vent design, and position play a critical role in the effectiveness of natural ventilation. In this study, computational fluid dynamics (CFD) was employed to investigate the effect of different roof vent designs along with side vents on the buoyancy-driven natural ventilation. The boussinesq hypothesis was used to simulate the buoyancy effect to the whole computational domain. RNG K-epsilon turbulence model was utilized, and a discrete originates (DO) radiation model was used with solar ray tracing to simulate the effect of solar radiation. The CFD model was validated using the experimentally obtained greenhouse internal temperature, and the experimental and computed results agreed well. Furthermore, this model was adopted to compare the internal greenhouse air temperature and ventilation rate for seven different roof vent designs. The results revealed that the inside-to-outside air temperature differences of the greenhouse varied from 3.2 to 9.6oC depending on the different studied roof vent types. Moreover, the ventilation rate was within the range from 0.33 to 0.49 min-1. Our findings show that the conical type roof ventilation has minimum inside-to-outside air temperature difference of 3.2oC and a maximum ventilation rate of 0.49 min-1.
        4,000원
        5.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        겨울철에 열손실을 줄이기 위해 많은 온실에서 보온커튼을 사용하고 있다. 그러나 적절한 보온커튼을 선택할 때 판단 자료로 활용할 수 있는 명확한 기준이 없는 실정이며 이를 위해서는 보온재의 보온 특성에 대한 정량적인 값이 필요하다. 본 연구에서는 BES를 사용하여 보온커튼의 관류열전달계수를 산정하는 시뮬레이션 모델을 개발하였다. 일중 및 이중 PE필름 피복에 대한 관류열전달계수의 실험값을 사용하여 시뮬레이션 결과를 검증하였다. 검증된 모델을 사용하여 문헌에서 제시된 각종 열적 특성을 가진 보온커튼에 대한 관류열전달계수를 산정하고 비교분석하였다. 개발된 시뮬레이션 모델은 다양한 보온커튼의 관류열전달계수를 산정하는데 활용될 수 있을 것이며, 제시된 관류열전달계수는 보온커튼의 성능을 정량적으로 비교하는데 유용하게 활용 될 수 있을 것으로 판단된다.
        4,000원
        7.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 온실작물 생육에 적절한 미기상환경을 제공하기 위한 최적의 조건을 찾아내기 위하여 TRNSYS 프로그램을 이용하여 온실의 구조 및 환경인자와 에너지공급기술들에 대하여 시뮬레이션을 실시한 연구논문들을 분석하였다. 본 연구의 목적은 온실에너지 관리를 위해 사용되고 있는 여러 가지 에너지시스 템과 기술들에 관하여 검토하고 이들에 대해 TRNSYS 시뮬레이션을 통해 실시한 효율분석에 관하여 검토하는 것이다. 사용가능한 에너지자원과 다양한 외부기상조건에 따른 에너지절감기술들의 성능을 분석하기 위한 여러 가지 시뮬레이션 모델들에 대해서도 검토하였다. 사용자가 정의하는 인자들을 사용하여 하이브리드 농업시설을 시뮬레이션 할 수 있는 TRNSYS 프로그램의 주요 구조들을 찾아내었다. 문헌검토에서 얻어진 결과를 토대로 TRNSYS 프로그램을 이용하여 온실의 에너지관리를 위한 시뮬레이션 모델을 개발하는데 필요한 몇 가지 중요한 결론들을 도출하였다. TRNSYS 프로그램은 앞으로 온실의 에너지 시뮬레이션을 수행하는데 크게 활용될 것으로 기대된다.
        4,000원
        9.
        2013.04 구독 인증기관·개인회원 무료
        The bulb mite (Rhizoglyphus echinopus) damages garlic, shallot and onion in the bulbs, corms and tubers. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among bulb mite population. Thus, there is need to find alternative control measures to suppress bulb mite population. Here, we report the screening result of pathogenic fungi for the control of R. echinopus. Initial screenings were performed using 352 isolates of entomopathogenic fungi from Korea soils. As results, 15 isolates of acaropathogenic fungi showed the pathogenicity to bulb mite supporting fungal conidiation. These isolates were identified as 3 isolates of Metarhizium flavoviride var. pemphigi and 12 isolates of Metarhizium pingshaense by microscopic examination and genetic sequencing of the ITS region and elongation factor-1 alpha. Selected 15 isolates were tested for their virulence against adult R. echinopus and the thermotolerance and the activity to UV-B irradiation of conidia. Additionally, the activities of chitinases and proteases produced by M. pingshaense were compared according to the medium. These acaropathogenic fungi would be considered promising for biological control of bulb mite.
        10.
        2013.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are natural pathogens of insects and contribute to the regulation of host insect populations in the environment. Several these fungi produce a wide range of secreted enzymes, secreted protein toxins and secondary metabolites to overcome host defenses and ultimately kill the host, and to defend host resources against competing pathogens and saprophytes. This study was performed to evaluate the antimicrobial activity of 207 entomopathogenic fungi form Korea soils against plant pathogenic bacteria Ralstonia solanacearum and plant pathogenic fungi Botrytis cinerea using dual culture technique on SDYA. As results, twelve isolates (5.7%) and six isolates (2.8%) showing the greatest inhibition against R. solanacearum and B. cinerea, respectively. The culture supernatant of these selected isolates completely suppressed the growth of the pathogen, indicating that suppression was due to the presence of antimicrobial compound in the culture filtrate. The stability test of the culture filtrate showed that the antimicrobial component was heat stable and not protein. These entomopathogenic fungal metabolites may be a good feature to be used in the development of a new biocontrol method of R. solanacearum and B. cinerea.
        11.
        2011.10 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae Sulzer, is one of the most important pests affecting protected and open-grown crops, because they cause direct damage by feeding on crops and indirect damage as virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among green peach aphid population. Thus, the development of entomopathogenic fungi as aphid biocontrol agents has received increasing interest as part of integrated control strategies. In this study, we report the screening result of pathogenic fungi for the control of green peach aphid. Initial screenings were performed using 347 isolates of putative pathogenic fungi from Korea soils. As results, 20 isolates of entomopathogenic fungi were isolated from cadavers of green peach aphid supporting fungal conidiation. These isolates were identified as three strains of Lecanicillium attenuatum, nine strains of Beauveria bassiana, one strain of Metarhizium anisopliae, one strain of Metarhizium flavoviride, five strains of Paecilomyces lilacinus, one strain of Aspergillus sp. by microscopic examination, genetic sequencing of the ITS region and Universally Primed PCR (UP-PCR). Based on the screening results, twenty isolates were tested for their pathogenicity against adult green peach aphid. All fungal isolates were pathogenic to green peach aphid but mortality varied with isolates. These entomopathogenic fungi may be useful to develop eco-friendly insecticide to control green peach aphid.
        12.
        2011.10 구독 인증기관·개인회원 무료
        The entomopathogenic fungi were an important natural pathogenic of insects that has been developed as potential biological control agents for many important agricultural, forest and medical pests. Several these fungi produce a wide range of secondary metabolites with high therapeutic value as antibiotics, cytotoxic substances, insecticides, compounds that promote or inhibit growth, attractor and repellent. Therefore, this study was performed to select the antibacterial activity of liquid culture filtrates of 347 entomopathogenic fungi form Korea soils against two pathogenic bacteria including Ralstonia solanacearum and Escherichia coli using novel method which represents a quick and easily applicable tool obtaining large number of samples. As results, eight-five strains (24%) and seventy-six strains (22%) of these fungal metabolites produced anti-R. solanacearum and anti-E. coli compounds, respectively. The preferential antibacterial activity against R. solanacearum and E. coli gives evidence that these entomopathogenic fungal metabolites might be useful as an agent for bacteria control and the technique was simple to operate and allowed a large number of samples to be handled concurrently.
        13.
        2011.05 구독 인증기관·개인회원 무료
        The two-spotted spider mite, Tetranychus urticae Koch, is an economically important pest of crops of plant grown in the field or greenhouse worldwide. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among spider mite population. Thus, there is a need to find alternative control measures to suppress spider mite populations. In this study, we report the screening result of pathogenic fungi for the control of spider mite. Initial screenings were performed using 352 isolates of putative pathogenic fungi from Korea soils. As results, 11 strains of acaropathogenic fungi were isolated from 8 cadavers of spider mite supporting fungal conidiation. These isolated were identified as four isolates of Beauveria bassiana (6, 2R-3-3-1, 2R-4-5, 2R-4-7), two isolates of Metarhizium anisopliae (4-2, 2-2), one isolate of Clonostachys rosea 5-2, one isolate of Lecanicillium attenuatum 4-1, one isolate of Pochonia suchlasporia 2R-3-1, one isolate of Aspergillus flavus 7 and one isolate of Isaria lilacinus 2R-4-6 by microscopic examination and genetic sequencing of the ITS region. Based on the screening results, eleven isolates were tested for their virulence against adult spider mites. All fungal isolates were pathogenic to spider mite but mortality varied with isolates. These acaropathogenic fungi may be useful to develop eco-friendly acaricide to control two-spotted spider mite.
        14.
        2006.12 구독 인증기관 무료, 개인회원 유료
        Vitrification has been suggested to be an effective method for the cryopreservation of human ES cells. However, the efficiency of vitrification with different vehicles remains a matter of ongoing controversy. The objective of this study was to assess the efficiency of cryopreservation in human ES cells by vitrification using different vehicles. A human ES cell line and a variety of vehicles, including microdroplet (MD), openpulled straw (OPS) and electron microscopic grid (EMgrid), were employed in an attempt to assess vitrification efficiency. In order to evaluate the survivability and the undifferentiated state of the postvitrified human ES cells, we conducted alkaline phosphatase staining and characterization via both RTPCR and immunofluorescence assays. The survival rates of the postvitrified human ES cells using MD, OPS and EMgrid were determined to be 61.5%, 66.6% and 53.8%, respectively. There also exist significant differences between slowfreezing and vitrification (p<0.01). However, no significant differences were detected between the vehicle types. Finally, the pluripotency of human ES cells after thawing was verified by teratoma formation. Cryopreservation using vitrification is more effective than slowfreezing, and the efficiency of vehicles proved effective with regard to the preservation of human ES cells.
        4,000원
        15.
        2016.05 서비스 종료(열람 제한)
        Background : This study was development of moisture tolerance and high-yielding Rehmannia glutinosa cultivar. Methods and Results : Segang is developed by the medicinal crop breeding team of National Institute of Horticulture and Herbal Science(NIHHS), Rural Development Administration(RDA), during the period from 2005 to 2015. The reproduction of Rehmannia glutinosa has been accomplished mainly by vegetative propagation with its seedlings have many variants. The cultivar was selected from seedling of Jihwang 1(check variety). The plant type of Segang is some rising from ground. Regional yield trials conducted at three site from 2014 to 2015. The root yield of Segang was 21.1ton per hectare, which was increased 12% compared with Jihwang 1. Also, Segang has higher catalpol content and dried root ratio compared with Jihwang 1. Conclusion : Segang is a moisture tolerance and high-yielding Rehmannia glutinosa cultivar.
        16.
        2014.09 서비스 종료(열람 제한)
        Cholesterol embolization syndrome (CES) is a multiple systemic disease caused by the embolization of cholesterol crystals from an atherosclerotic plaque of a proximal large-caliber artery, which results in the occlusion of distal small to mediumsized arteries. CES is characterized by development of a multitude of small emboli over time, and should be distinguished from arterial thromboembolism, which occurs through the obstruction of medium-sized to large arteries by one or a few large emboli. We report on a case of CES initially presenting as acute limb ischemia following an intervention for iliac artery occlusion.
        19.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new standard rose cultivar 'White Christmas' was bred from the cross between red standard cultivar 'Red Queen' and pink standard cultivar 'Vivaldi' at the National Horticulture Research Institute. The cross was made in 2001 and `White Christmas' was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. 'White Christmas', a white standard cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are 123.8 stems/m2/year in yield, 82.3 cm in length of cut flower, 11.0 cm in flower diameter, 60.1 in petal number, and 12.2 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Tineke'.
        20.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new standard rose cultivar 'Magic Pink' was bred from the cross between light yellow standard cultivar 'Medeo' and pink standard cultivar 'Veronica' at the National Horticulture Research Institute. The cross was made in 2001 and 'Magic Pink' was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. 'Magic Pink', a pink standard cultivar grows vigorously and has fashionable flower color. The major characteristics of this cultivar are 184.8 stems/m2/year in yield, 63.0cm in length of cut flower, 7.2 cm in flower diameter, 28.5 in petal number, and 10.4 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Noblesse'.
        1 2