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        검색결과 18

        1.
        2016.05 구독 인증기관·개인회원 무료
        생체적합성과 흡습 특성이 있는 polyamide6 (PA6)를 혈액투석용 분리막으로 사용하기 위해 16 wt% PA6 고분자 용액을 전기방사하여 제조하였다. 제조된 PA6 nanofiber membrane은 직경(fiber diameter), 표면특성, 기공의 크기 분석을 통해 혈액투석용 분리막으로 최적화하였다. PA6 nanofiber membrane는 제 올라이트가 첨가된 친수성 고분자 용액으로 개질하여 혈액 속 노폐물인 creatinine 흡착 제거용 분리막으로 사용하고, creatine의 흡착효과는 UV-visible 분석으로 확인하였다.
        2.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 노지채소 작물인 고추를 대상으로 이상 고온조건을 인위적으로 부여하여 화분발아력을 검정 하며, 이상 고온에서의 화분발아력을 향상시킬 수 있는 방법을 강구하기 위해 수행되었다. 고추에서 화 분 발아에 최적온도는 25℃였고, 27.5℃와 30℃에서는 화분발아율이 낮았다. 화분발아에 적합한 sucrose 농도는 10~15%였고, 30% 이상의 농도에서는 화분 발아율이 감소하였다. 화분발아 배지의 적정 pH 5.5 ~6.5였고 이들 조건에서 화분발아율이 높았고, 화분관 신장도 좋았다. 화분 채취시간에 따른 화 분 발아율은 채취 시간에 따라 차이가 있었다. 전반적으로 오전 10시에 채취한 화분에서 발아율이 가장 높았고, 반면 오후에 채취한 화분일수록 화분활력이 저하되었다. 화분발아 배지에 아미노산인 asparagine과 glutamine를 첨가하면 고온에서 화분발아율이 향상되었다. 또한 폴리아민류인 putrescine 과 spermine도 화분 발아율을 향상시켰다. 전반적으로 고온에서 고추 화분발아성을 증진시킬 수 있는 첨가물질 및 처리농도는 supermine 1 mM 처리였고, 대조구에 비해 화분발아율이 15.0% 향상되었다.
        4,000원
        3.
        2006.09 구독 인증기관·개인회원 무료
        The magnetic ferrite nanoparticles were synthesized and coated by silica precursor in controlling the coating thicknesses and sizeses. The surface modification was performed with amino-functionalized organic silanes on silica coated magnetic nanoparticles. The use of functionalized self-assembled magnetic ferrite nanoparticles for nucleic acid separation process give a lot of advantages rather than the conventional silica based process.
        4.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배의 과경부에 지베렐린을 처리하면 과실비대에 효과는 있으나 저장성이 떨어지는 단점이 있다. 본 시험은 지베렐린 처리가 저장성을 향상시키기 위하여 폴리아민의 처리부위와 처리농도에 따른 과실의 특성변화를 조사하였다. 시험품종은 '황금배', '영산배', '추황배'로 하여 제베렐린을 만개 30일 후에 처리하고 폴리아민을 수확 7일 전에 과총 엽과 수관에 100, 200, 500ppm으로 엽면살포 하였다. 지베렐린 처리에 의하여 과중은 모든 품종에서 10% 정도 커졌고 경도는 0.3~0.4kg/Φ5mm만큼 낮아졌으나 당도와 식미는 차이가 없었다. 과경부의 형태적 특성은 지베렐린 처리가 무처리에 비하여 수(髓, pith) 부분에서 내피세포까지의 거리와 내피에서 표피세포까지의 거리가평균 42.0%신장되어 양 수분의 이동이 활발해지고 그에 따른 공급량이 많아져 과실의 무게가 비대해 진 것으로 추정할 수 있었다. 저장 30일 후 과실의 특성을 보면 '황금배'는 과총엽 살포의 스퍼미딘 200ppm이, 수관살포는 스퍼미딘 500ppm에서 과육의 경도가 높게 유지되어 식미가 양호하였다. '영산배'와 '추황배'도 비슷한 경향으로 주당 살포량이 적은 과총엽 200ppm살포처리가 저장성 증진에 효과적이었다.
        4,000원
        9.
        2007.02 KCI 등재 서비스 종료(열람 제한)
        The effect of precoating of silica with polyamine surfactants on the adsorption of five model compounds containing asphalt-like functionalities was studied. Hexadecyltrimethylammonium chloride (HDTMA) and 1-hexadecylamine were used for silica precoating. The model compounds representing five asphalt functionalities were benzoic acid, phenol, benzylbenzoate, benzophenone, and quinoline. All the adsorption isotherms conformed well to the Langmuir adsorption model. All the model compounds showed decreased adsorption with the HDTMA precoating. However, two acidic compounds, benzoic acid and phenol, showed enhanced adsorption on the silica precoated with 1-hexadecylamine. In aqueous solutions, the adsorption of the acidic compounds were in the following order: silica precoated with 1-hexadecylamine > silica precoated with HDTMA > uncoated silica.
        10.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 polyamine이 쪽 모상근 배양에서 뿌리의 생장과 indigo 생합성에 미치는 영향을 조사하였다. 1. 토양미생물인 Agrobacterium rhizogenes R1000을 이용하여 쪽 자엽으로부터 모상근을 효과적으로 유도하여 배양하였다. 2. 모상근 생장과 인디고 생합성이 polyamines(putrescine, spaermidine, spermine) 처리에 의하여 향상되었으며, 그 중 putrescine이 다른 polyamines에 비하여 효과적이었다. 3. Putrescine 70 mg/l 처리가 모상근의 생육(4.4 g/flask)과 인디고 생합성(216.3 ug/g)의 향상에 최적조건으로 조사되었다.
        11.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation
        12.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        Rice (Oryza sativa L.) plants were cultivated to examine changes in antioxidative defence mechanism induced by elevated ozone levels. Catalase activities in tolerant Jinpumbyeo and susceptible Chucheongbyeo under ozone fumigation were reduced at 5 hrs and 3 hrs after ozone fumigation, respectively. With the increased ozone supply, peroxidase activity in Jinpumbyeo was steadily enhanced whereas in Chucheongbyeo it was not changed. Four SOD-isozymes were detected by NBT staining of native-PAGE. Two isozymes of them were obviously induced by ozone supply, particularly in Jinpumbyeo. The continuous ozone fumigation increased remarkably putrescine levels in leaves whereas it did not affect the levels of spermidine and spermine. In this study, it was implied that ozone in cell inhibits strongly diamine oxidase and thus promotes ethylene biosynthesis which will cause the senescence in rice plants.
        14.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        Polyamine was synthesized for the drinking water treatment. Polyamine was produced by the two step polycondensation of dimethylamine(DMA) and epichlorohydrin(EPI) and its properties were characterized. The effects of mole ratio of [DMA]/[EPI], reaction temperature and reaction time on synthesis of polyamine were investigated. Polyamine flocculant was applied to Nak-dong river raw water to examine its efficiency in reducing turbidity. The synthesized polyamine was effective as flocculant for drinking water treatment. The addition of 1 ㎎/L of polyamine flocculant caused the reduction of 50% PAC (polyaluminium chloride).
        15.
        1997.09 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of polyamines, salt strength. sucrose and gelling agents on the regeneration of plantlets by meristem culture of Aloe arborescens Mill. and Aloe vera L.. Shoot multiplication was more effective when 10mg/ l spermine in Aloe arborescens and 1mg/ l spermidine in Aloe vera added into MS medium than when other polyamines were treated into media. A quarter strength of MS medium was effective for rooting of shoots regenerated. Higher concentration of sucrose (45g/ l) was more effective for shoot regeneration. Addition of 4g/ l gelrite into the medium was effective for induction of multiple shoots from Aloe than that of agar or other concentrations of gelrite. When plantlets regenerated from meristem culture were transferred to pot. survival rate of plantlets was 80% on perlite and was 95% on vermiculite. respectively.
        16.
        1996.10 KCI 등재 서비스 종료(열람 제한)
        Rice plants cv. Koshihikari, were subjected to the biologically effective ultraviolet-B (UV-B_BE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) kJ m^-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dry weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV-B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemical protectant against increased UV-B radiation in rice plants.
        18.
        1993.12 KCI 등재 서비스 종료(열람 제한)
        Effects of polyamines on chlorophyll and protein content, and δ-aminolevulinate dehydratase(ALAD) activity were investigated during the greening of mung bean cotyledons. Polyamines stimulated chlorophyll formation in greening cotyledons, and this effect was enhanced by KCl. The changes in protein content were similar to the changes for chlorophyll content. The excision entailed an increase in ALAD activity. Then a decrease appeared after 48 h incubation on water in the dark. It was more precocious in the light, but was accelerated when the cotyledons were illuminated after a dark preincubation. Putrescine had little effect on ALAD activity in the dark. In the light, putrescine prevented the decrease in ALAD activity and enhanced this activity when a dark preincubation preceded illumination. KCl had a slight stimulating effect in the dark, but was uneffective in the light. The combination putrescine+KCl was devoid of stimulating effect. The results obtained suggest that plastid development of mung bean cotyledons during greening was affected by polyamines and light and that polyamines may play a role in the regulation of plastid development.