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        검색결과 15

        1.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 과학 영재 프로그램을 개발하고 개선하는데 반영하고자 2002년도 서울 대학교 과학 영재 교육센터에서 운영된 과학 영재 프로그램의 각 주제에 제시된 학습 목표, 과학적 모형, 과학 탐구의 인지 과정을 분석하였다. 교육 목표와 과학적 모형, 탐구 활동의 세 요소들은 과학 교육 과정의 구성에 있어서 중요하다는 판단 아래 각 요소들이 제시된 정도를 파악한 후 이들의 수준이 영재 학생들의 인지적 요구를 충족시키는지에 초점을 두어 분석 결과를 해석하였다. 이에 따라 교육 목표의 인지 영역 중에서 상위 사고력 영역에 해당하는 종합 영역, 과학적 모형 중에서 상위수준의 추상성과 복잡성 모형인 다 개념-과정 모형, 과학 탐구의 인지 과정 중 창의성 영역에 해당하는 실험 설계의 인지 과정이 과학 영재 학생들을 가르치는 데 중요한 항목임을 전제하였다. 분석 결과 서울 대학교 과학 영재 프로그램의 각 주제에 제시된 교육 목표는 상위사고력 영역과 하위사고력 영역이 비슷한 비율로 나타나며, 그 중에서 종합 영역은 낮게 나타났다. 과학적 모형은 다 개념-과정 모형보다는 단일 개념 모형이 많았으며 추상성 수준은 중간 정도였다. 과학 탐구의 인지 과정은 실제 과학 탐구의 인지 과정을 고르게 다루지는 않았다. 특히 실험 설계의 인지 과정은 적게 다루고 있었다. 따라서 분석한 과학 영재 프로그램이 과학 영재들의 인지적 요구를 충족시키기 위해서는 종합 영역의 교육 목표, 다 개념-과정 모형, 실험 설계의 인지 능력을 더 많이 반영해야 한다.
        4,000원
        2.
        2017.02 KCI 등재 서비스 종료(열람 제한)
        Background: The light emitting plasma (LEP) has recently attracted attention as a novel artificial light source for plant growth and functional component enhancement. We investigated the effects of LEP on whitening and antioxidant activities of the plant parts of perilla. Methods and Results: Previously germianted seeds of perilla were cultivated under different light conditions (fluoresce lamp, LED red, blue, white, green, and LEP) in a culture room for 2 months. Parts of perilla were harvested and extracted in 70% EtOH. The extracts were used to detect total phenolic contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and tyrosinase inhibition activity as indicators of biological activity. Biological activity was highest in seedlings grown under LEP. The total phenolic content was highest in the stems and the total flavonoid content was highest in the roots of perilla exposed to LEP. The DPPH and ABTS radical activity in all the parts of perilla exposed to LEP were higher by approximately three-fold compared to that in the control (fluoresce lamp). The reducing power values of perilla significantly increased after treatment with LEP. In addition, all the extract of perilla plants exposed to LEP promoted the tyrosinase inhibitory activity. These results suggest that LEP can be an important artificial light source for enhancement of biological activity. Conclusions: LEP could promote whitening and antioxidant activity of perilla.
        3.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Background: Sorghum is a major cereal food crop used in many parts of the world. It has been grown on a subsistence level by farmers, under various conditions of environmental stresses in the semi-arid tropics of Africa and Asia. This plant has received significant attention because of its ability to reduce cholesterol in the blood, and its anti-dementia, antioxidant, and antimicrobial properties. It is possible to develop a functional and commercially viable sorghum variety by using superior cultivars of sorghum. The objective of this study was to build a database of superior sorghum accession.Methods and Results: We used 250 sorghum accessions collected from different geographical bioregions in Korea. We determined various agronomic characters including germination rate and ear length of these accessions. To determine the antioxidant capacity, we measured the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt radical scavenging activity, total phenolic contents, and total flavonoid contents. Accession 189 showed higher germination (> 80%) than the other accessions. Higher 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was observed in 11-SB-078 (RC50; 1.89 ± 2.88 μg/ml), and higher 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt radical scavenging activity was recorded in 11-SB-116 (RC50; 35.48 ± 2.42 μg/ml) than in the other accessions. The ear length ranged from 15 ㎝ to 48 ㎝, the total phenolic contents ranged from 3 ㎎• GAE/g to 77 ㎎• GAE/g, and total flavonoid contents ranged from 0.09 ㎎• QE/g to 1.07 ㎎• QE/g.Conclusions: Among 250 sorghum accessions, we selected 10 with both superior agronomic characters and highly functional food quality.
        4.
        2016.10 서비스 종료(열람 제한)
        Background : The study about ginseng cultured roots have been reported mainly ginsenosides in saponins family. Other phytochemical such as non-saponins of fatty acid has been revealed its bioactive activity including anti-oxidation, whitening, anti-cancer. Supercritical extraction (SE) process mainly refer to the extraction with CO2, is usually from a solid matrix, is a sample preparation step for analytical purposes. SE produce no residual solvent and possess high stability of the extract component, which is advantageous for fatty acid analysis. Methods and Results : Fermented ginseng cultured roots used in the experiment were used for fermentation using Pediococcus pentosaceus. SE performed at different temperature, pressure and extraction time using non-fermented and fermented ginseng roots. Further we fractionated from fermented ginseng using Methanol, Hexane, Ethanol, Ethyl acetate and Butanol. We compared fatty acids contents ginseng extractions by GC analysis. Methyl linoleate contents was 44% of fatty acids supercritical extraction contained. The contents of Methyl linoleate was the most dominant component among 37 types of fatty acids by SE and other extractions solvent. Total fatty acids contents obtained by SE process from fermented ginseng (1325.61ppm) was twice than from non-fermented ginseng (618.47ppm). Conclusion : Fatty acids contents by SE was increased at high pressure. The best condition for fatty acids contents extraction was 60℃, 350bar and 3h.
        5.
        2016.10 서비스 종료(열람 제한)
        Background : Perilla frutescens L. is valuable as a medicinal plant as well as a natural medicine and functional food. Limonene perilla collected from various places showed 60% limonene compounds. However biological activity of these accession has not been reported before. Therefore, this study was conducted to investigate the biological activity of limonene perilla. Methods and Results : Fractional solvent extracts were obtained by using organic solvents such as n-hexane, chloroform, ethyl acetate, n-BuOH, and aqueous solvent from different parts of limonene perilla extracted initially in 70% EtOH. We investigated the effects of limonene perilla on total phenol and flavonoid contents, FRAP (Ferric Reducing Antioxidant Power), total saponin contents and tyrosinase inhibition activity. Leaves of limonene perilla produced the highest total phenolic contents (29.88 mg·CAE/g), flavonoid (8.39 mg·QE/g) and saponin contents (47.77 mg·GIE/g) than stems and roots of limonene perilla. FRAP of leaves was 823.00±3.58 μM·FeSO4·E/mg. Tyrosinase inhibition activity rate was 40.31% in 70% ethanol extracts from leaves of limonene perilla. Conclusion : This results suggest that leaf of limonene perilla fractions has significant antioxidant activity. Also, limonene perilla could be used as a functional biomaterial in developing cosmetics and functional foods.
        6.
        2016.10 서비스 종료(열람 제한)
        Background : Temperature is major factor for growth plant. Recently, because of global warming, abnormal temperature included drought, deluge, sudden temperature change and heavy snow damaged crops in the world. In Korea, crops have been sensitive to low temperature on early growth stage, e.g. fruit tree and ginseng, were damaged owing to sudden heavy snow and cold on Spring. Therefore, recently interest in cold resistance crops were increased in demand rapidly. This study was performed to establish transgenic Nicotiana benthamiana by transforming cold resistant gene related to cold tolerance S-adenosylmethionine synthetase (SAMS) isolated from Miscanthus sinensis. Methods and Results : Total RNA was extracted from leaves of M. sinensis using Trizol assay and isolated MsSAMS. Isolated MsSAMS was insert into SacⅠ- XbaⅠ sites of pMBP1 vector. The vector was transformed to Agrobacterium tumefaciens strain LBA4404 by DH5α. A. tumefaciens with binary plasmid were selected at YEP medium supplemented with kanamycin. Cut leaves of tobacco were co-cultured with selected A. tumefaciens. Co-cultured leaves was grown on regeneration medium for a month at dark condition, and transferred to at light condition. Regeneration shoot from callus were excised and transferred to root-induction medium. Approximately, 58% of leaves explant produced callus. Nearly, 30% of callus had shoot and approximately, 94% of shoots were rooted in root-induction medium. Conclusion : We established an efficient transformation system of N. benthamiana transformed by using MsSAMS gene related to cold tolerance isolated from M. sinensis. We may use the produced transgenic plants to prevent damages carried by cold.
        7.
        2016.10 서비스 종료(열람 제한)
        Background : Perilla frutescens L. is a bisexual, annual plant belonging to the Labiatae. Dormancy period of Perilla seed usually ranged from 85-200 days. The germination enhancing effects in a reduced seed vigor during the GA3 treatment has been reported. Objectives of the present study was to evaluate the effect of GA3 on germination rate and the expression of germination-related genes expression by using perilla seeds. Methods and Results : Three different cultivars (Saeyeopsil, Okdong) and accession (line 141) of perilla were used in the experiment and treated with GA3 at different concentration (50, 100, 300, 500 μM) for one day at dark condition. Germination test for perilla seed was carried out by using 100 perilla seeds treated with GA3 at 25℃. Rate of germination were evaluated after 10 days and the experiments were repeated three times in similar condition. Samples were collected from each cultivar and accessions for RNA extraction. After cDNA synthesis quantification, templates were subjected to RT-PCR using actin primers. EST blast performed for sequencing the RT-PCR products. Conclusion : Result showed that 100μM GA3 treated seeds of three perilla cultivars and accessions showed the highest germination rate. However, concentration of GA3 over 100 μM and lower than 100 μM resulted into reduced germination rate. Furthermore, expression of germination-related genes from 100 μM treated GA3 was higher compared to untreated sample by using 100 μM GA3 treated sample by using pC12, pJ14 primers.
        8.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Background: This study was conducted to investigate the effects of germanium treatment on the growth and organic germanium production in the roots of Oplopanax elatus plantlets. Methods and Results: O. elatus plantlets were cultured in Murashige and Skoog (MS) medium with different concentrations of germanium dioxide (GeO2) to analyze optimum growth conditions. Exogenous treatment of 10 ㎎/ℓ GeO2 promoted growth and an increase in the contents of chlorophyll a, b and carotenoid in O. elatus. The germanium accumulation and production in roots of O. elatus plantlets treated with organic germanium reached the highest levels. The growth of the aerial and underground portion of O. elatus with organic germanium was greater than that of the control. The accumulation and production of organic germanium reached the highest level (40.89 ㎍/plantlet) with the treatment of 50 ㎎/ℓ GeO2. Antioxidant activity measured by DPPH and ABTS assays also increased with the germanium treatment and improved the DPPH and ABTS radical activity by 200% compared with that in the control. In addition, the total phenol and flavonoid contents of the plantlets with a treatment of 50 ㎎/ℓ GeO2 were higher than in the control. Conclusions: Taken together, the growth of O. elatus was increased with the treatment of 50 ㎎/ℓ GeO2 germanium and the biological references improved, with increased antioxidant activity and organic germanium production.
        9.
        2016.05 서비스 종료(열람 제한)
        Background : Miscanthus is a diploid hybrid and a temperate, perennial, cross-pollinating grass used as bioenergy plant, biomass production and high quality cellulose and ethanol production. This study was to determine an efficient transformation system for Miscanthus sinensis, and to optimize factors and conditions required for expression of MsCOMT–AS gene. Methods and Results : An efficient transformation of callus from M. sinensis was established using Agrobacterium tumefaciens strain LBA4404 harboring a binary vector pMBP1. In order to establish stable transformation system, we obtained high transformation rate from callus by various transformation factor explant type, strain, co-culture periods, acetosyringone concentration, and selective marker. Finally, in this study, seven putative transgenic plants were obtained. Through various tests including PCR analysis and southern blot were to detect antisense of COMT digested Xba I and Sac I restriction enzymes. The biomass of the control plant was superior than transgenic plants. Conclusion : This study was to develop transgenic Miscanthus sinensis by Agrobacterium tumerfeciens mediated transformation to produce high bioethanols and to reduce the lignin content of transgenic plants. Detailed characterization of the transgenic plants revealed interesting finding about COMT gene expression in the segregates
        10.
        2016.05 서비스 종료(열람 제한)
        Background : Ginsenosides, the main ingredient of ginseng roots can be confirmed various physiological activity such as anticancer, antioxidant, a natural ginsenosides is there a structure to be absorbed into the body does not work well absorbed through this process biologically active thus a high conversion ginsenosides. β-glucosidase enzyme is observed in several of the microorganism with an enzyme that serves to convert a ginsenoside prosper that is absorbed into the body. Methods and Results : To view a primary β-glucosidase activity, the bacteria were innoculated in esculin agar medium and the color change of the media were measured by the time and degree of changing color. In the other method, 5 mM of p-nitrophenyl-β-D-glucopyranoside (pNPG) containing 25 mM phosphate buffer solution (pH 7.0) was added to 50 ul enzyme solution. Then the solution was added to 50 ul reaction for 5 min at 30°C. The amount of p-nitrophenol liberated measured at 405 nm absorbance. The experimental results showed higher β-glucosidase activity in Pediococcus pentosaceus, Leuconostoc mesenteroide, Leuconostoc mesenteroides subsp. cremoris, and Paenibacillus polymyxa by using esculin agar medium method. Similarly in second method, β-glucosidase activity was higher in P. pentosaceus 402.32±11.43 unit/l, L. mesenteroide 353.73±14.64 unit/l, Lactobacillus sakei 198.4±15.47 unit/l Lactobacillus plantarum subsp. plantarum 164.1±8.12 unit/l. Conclusion : The result that the β-glucosidase activity was higher in P. pentosaceus, L. mesenteroide, and L. plantarum subsp. plantarum as compared to tested microbes. Therefore selected bacteria can be used in the industry of functioned foods and beverage to improve human healths.
        11.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to establish the optical storage condition in cutting slips of Lycium chinense Mill. We investigated the different influential growth factor of this plant including two soil types (soil and vermiculite) and storage methods (gauze, parafilm, vinyl, and paper). Our result revealed that the formation of axillary bud was highest (4.8 ± 0.75 ea) from the cutting slips stored in vinyl and vermiculite treatment. Root length was long (2.8 ± 0.13 ea) in parafilm storage using soil. Maximum plant height was 135.33 ± 12.81㎝ with gauze storage using vermiculite. The number of leaves was maximum (130 ± 2.5 ea) at 90 days from the cutting slips of gauze storage using vermiculite. Highest number of fruit was harvested (149 ± 16.05 ea) from the cutting slips stored in parafilm and grown in vermiculite. It can be concluded that the storage treatment and soil type influence the affecting to general growth of Lycium chinense Mill.