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        검색결과 241

        121.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        Interlellkin • 8(IL-8) is an important cytokine involved in tllmor growth and angiogenesis in a variety of malig nancies. bllt the regll lation of IL-8 in 01 외 cancer cells are llnderstood . We invesLigated whether mi togen-activated protein kinases pathway is involved in iron chelator-mediated lL-8 produdion in inunortalized and malignant oral keratinocytes. In this study we examined the role of p38 and extracellular signal- reglllated kinase• 1/2 in the expression of [L-8 by DFO. Incllbation of IHOK and HN12 cel ls with DF'O increased the expression of 11-8 mRNA. as well as the release of IL-8 protein. The signal transdllction study revealed that both p38 and ERK1/2 were significantly activated in response to DFO. Accord ingly. the selective inhibitors for both kinases‘ eit her a lone or combination. abolished DFO- induced lL-8 secretion. indicating an importance of MAP kinase pathway. Interestingly. however‘ inhibition of the p38 and ERK pathway more attenuated IL-8 secretion in IHOK than in HN12 cells. DFO induced NF-kB activation , suggesting a NF-kB- dependent mechanism in DFO- induced IL-8 production. In addition, p38 and ERK inhi bition resulted in the accelerated degradation of lL-8 mRNA, suggesting that in IHOK and HN12 cells, p38 and ERK cunLr iullLe Lo DFO imluced IL-8 secretion by IHOK and HN12 cells via a posttranscriptional mechanism that involves stabilization 01' the IL-8 transcript. Finally. we investigatecl llsing specific inhibitors : 8NP and G8NO for NO c1onor. PDTC for potent inhibitor of NF-kB. Cycloheximide for inhibition of de novo protein synthesis. We observecl 8NP ancl PD1'C clepenclent IL-8 gene incluction in IHOK cell s. but not in HN12 cells used specific inhibitors‘ Collectively. these results demonstrate that‘ targeting MAP kinase ancl NF-kB pathway may be a potentiaI approacb to controlling the angiogenes is ancl growth 이 human oral cancers
        128.
        1995.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선형 변단면 부재의 삼차원 공간에서의 해석을 위하여 강도행렬을 유도하였다. 변단면 부재의 구조물을 해석하기 위하여 본 연구에서 유도된 강도행렬을 사용하여 구한 결과와 분할부재를 균일단면 탑 형태로 표현하여 ANSYS에서 구한 결과를 비교하여 본 연구의 결과 효율성 및 정확성이 증진된 것을 확인하였다. 본 연구에서 유도된 강도행렬은 변단면 부재와 균일단면 부재의 해석에 사용할 수 있다.
        4,000원
        129.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배추좀나방과 담배거세미나방 유충에 대한 30종 한방 식물체 메탄올 조추출몰의 살충활성 및 섭식 저해활성을 잎침지법을 이용하여 5,000ppm으로 검정하였다. 황련의 추출물은배추좀나방에 대해 살충작용을 보였다. 길경, 사삼, 세신, 오배자 및 자초의 추출물은 배추좀나방 유충에 대해, 목통 및 속새의 추출물은 담배거세미나방 유충에 대한 강한 섭식저해활성을 보였으나, 오배자와 황련의 추출물은 이들 나비목 유충 모두에 강한 섭식저해활성을 나타내었다.
        4,000원
        130.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        The adzuki bean (Vigna angularis L.) is a red-grained legume that has a number of essential nutrients and is used in traditional dishes in Asia. Adzuki bean industrial by-products are also a potential low-cost source of some unique bioactive polyphenols. Hence, here, the authors aimed to perform a comparative study of the phytochemical profiles of the leaves and seeds of the adzuki bean and compare their antioxidant, α-glucosidase inhibition, and tyrosinase inhibition activity. The authors assessed antioxidant activity by DPPH, ABTS, FRAP, PR, TPC, and SOD assays, which showed wide variation, respectively. From the relative antioxidant capacity index results, 10 adzuki bean landraces were selected to compare for phytochemicals and bioactivity using leaf and seed extracts. Antioxidant, α-glucosidase inhibition, and tyrosinase inhibition activity in the leaf extracts were higher than in the seed extracts, and there were more flavonols and isoflavones in the leaf extracts than in the seed extracts. This study demonstrated that adzuki bean leaf extracts could be a new natural antioxidant or antidiabetic agent and a skin whitener and can also be used in industrial applications.
        131.
        2017.08 서비스 종료(열람 제한)
        Background & Objectives: Methoxychlor(MET), an organochlorine insecticide, has been thought a potent endocrine disrupting chemical. The present study was undertaken to examine whether short-term exposure to MET can alter the onset of puberty and the associated reproductive parameters such as hormone receptor expressions in prepubertal female rats. Method: MET (1, 10 and 100 mg/kg/day) was administered daily from postnatal day 25 (PND 25) through the PND 34, and the animals were sacrificed on the PND 35. The first V.O. day was monitored, and the weights of reproductive tissues were measured. To assess the structural alterations in the ovary and uterus, the tissues were embedded in paraffin and stained for histological analysis. The transcriptional activities of hypothalamic and pituitary genes were measured using quantitative RT-PCRs. The uterine and hypothalamic proteins were extracted and used for the ER western blotting. Results: As a result, 100 mg group showed advanced V.O. than control, 1 mg group and 10 mg group. The wet weights of ovaries from MET-treated animal dose-dependently increased. The uterine weights were increased in 1 mg group and 10 mg group, while the 100 mg group samples were not significantly different from control tissues. The adrenal, kidney, spleen and thymus weights were not shown any significant change. Corpora lutea and fully grown follicles were observed in the ovaries from the 100 mg group, while numerous primary and secondary follicles were observed in the ovaries from control group. Myometrial thickness of MET-treated group was dose-dependently increased. Epithelial hypertrophy and well-developed glands were observed in the uterus from the 10 mg groups. Conclusions: The present study demonstrated that the short-term exposure to MET during the critical period of prepubertal stage could activate a reproductive endocrine system, resulting the early onset of puberty in immature female rats. Our study suggests that MET’s disrupting effect might be derived from premature activation of key reproduction-related genes in hypothalamus-pituitary neuroendocrine circuit.
        132.
        2017.05 서비스 종료(열람 제한)
        Background : Undulatum Rhubarb, commonly produced in domestic, is rhizome of Rheum undulatum L. that belongs to the family Polygonaceae. It also can be used as a substitute of R. palmatum L., R. tanguticum Maximowicz ex Balf., and R. officinale Baillon which completely depend on import system. However, there should be clear clarification among Undulatum Rhubarb and Rhubarb, because Undulatum Rhubarb contains rhaponticin as marker compound that is not indicated at Rhubarb. Some of the recently imported Undulatum Rhubarbs have been found to be Rhubarb. Also, it is known that only Undulatum Rhubarb is cultivated at domestic environment. But some plant origins of Rhubarb are grown in Korea, too. Further study are needed to clarify clear origin between Undulatum Rhubarb and Rhubarb. Thus, we collected some domestically cultivated samples and identified them. Methods and Reseults : Rheum undulatum L., Rhubarb, Rheum tanguticum Maximowicz ex Balf. which were cultivated in Gangwondo Agricultural Research and Extension Services in Cheorwon were collected and anayzed the DNA sequences. We also compared DNA sequences in Rhubarb collected from England and R. rhabarbarum L., R. undulatum L., and R. franzenbachii on NCBI. As a result, two kinds of rhubarb cultivated in the test plantation were identified as R. rhabarbarum and R. officinale. In addition, R. undulatum (plant origin of Undulatum Rhubarb) was identified as Rhubarb (Rheum rhabarbarum) in England with 99 - 100% identical in nuclear ITS gene region. Conclusion : R. undulatum, plant origin of Undulatum Rhubarb, is reported as synonym of R. rhabarbarum, R. franzenbachii. Rheum speices which are cultivated as tester in Gangwondo Agricultural Research and Extension Services in Cheorwon are estimated as R. undulatum and R. officinale. Therefore, not only Undulatum Rhubarb but Rhubarb could be grown in Korea.
        133.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the antioxidant activity in the leaves and stems of 50 tomato accessions, in order to examine the possibility of using tomato by-products as a functional material. The extracts of the leaves (LE) and stems (SE) were analyzed for DPPH, ABTS, and total polyphenol content (TPC). Antioxidant activities and TPC differed significantly between the LE and SE of the 50 tomato accessions. TPC in LE and SE showed wide variation, ranging from 24.4 to 60.6 and 12.5 to 18.8 ㎎ GAE/g, respectively. The DPPH and ABTS antioxidant activities of LE ranged from 10.0 to 38.2% (scavenging effect) and 20.8 to 59.0 ㎎ ASC/g, respectively, while the DPPH and ABTS measurements of SE were 1.4 to 8.8% and 2.2 to 22.5 ㎎ ASC/g, respectively. As assessed by the relative antioxidant capacity index (RACI), IT033117 and IT203466 had the highest antioxidant activity in LE and SE, respectively. These results will expand the knowledge of antioxidant activity and provide information on tomato accessions valuable for the development of functional foods and food additives.
        134.
        2016.10 서비스 종료(열람 제한)
        Background : The objective of this study was to Amomum tsao-ko Crevost et Lemarié, (Zingiberaceae) is widely distributed among several countries in South Asia and Southeast Asia. It is a well known spice in Asia, produces a nice refreshing effect in the mouth. Additionally, it's dried fruit is used in Traditional Chinese Medicine (TCM) for cardiac diseases, edema, eye trouble, skin, itch and impotence. The objective of this study was evaluated the inhibitory activity on adipogenesis in 3T3-L1 cells from A. tsao-ko. Methods and Results : The fruits of A. tsao-ko were extracted with 80% EtOH two times at room temperature. The EtOH extract was suspended in distilled water and partitioned with solvent to give CH2Cl2, EtOAc and n-BuOH. The CH2Cl2 was suspended in n-hexane and partitioned with solvent to give 50%, 70% and 90% MeOH. The purification of each fraction by column chromatography separation and HPLC analysis. Consequently, several constituents were isolated five known compounds. The identification and structural elucidation of compounds were established by using NMR (1D and 2D) and mass spectrometry. Conclusion : These compounds were identified as fluorenone (1), phenanthrene (2), anthracene (3), methyl linolenate (4), 1,2-benzenediol (5). All isolates were tested for their inhibitory activities on adipogenesis in 3T3-L1 cells.
        135.
        2016.10 서비스 종료(열람 제한)
        Background : Amomum tsao-ko (Zingiberaceae) is widely distributed among several countries in Asia. It’s dried fruit is widely used in Korea for medical plant, China and Japan for the treatment of dyspepsia, eliminates, vomiting, abdominal pain, phlegm, warms the spleen, and malaria. In this study, we describe the structural determination of the new compounds and the inhibitory activities of isolated compounds against LPS-induced NO production in RAW264.7 cells. Methods and Results : The fruits of A. tsao-ko were extracted with 80% EtOH two times at room temperature. The EtOH extract was suspended in distilled water and partitioned with solvent to give CH2Cl2, EtOAc and n-BuOH. The CH2Cl2 was suspended in n-hexane and partitioned with solvent to give 50%, 70% and 90% MeOH. The purification of each fraction by column chromatography separation and HPLC analysis. Consequently, one new benzaldehyde (1) and two new cycloterpenals (2 and 3) along with five known compounds (4 –8) have been isolated from the fruits of A. tsao-ko. The structure and relative stereochemistry were determined from HRMS, 1D and extensive 2D NMR techniques as well as by comparison of their data with the published values. Conclusion : These compounds were identified as Amotsaokonal A (1), Amotsaokonal B (2), Amotsaokonal C (3), methyl linolenate (4), trans-nerolidol (5), (2E)-dodecenyl acetate (6), (2E)-dodecenyl acetate (7), and pyrrole-2-carboxylic acid (8). All isolates were tested for their inhibitory activities on LPS-induced nitric oxide production in RAW264.7 cells.
        136.
        2016.10 서비스 종료(열람 제한)
        Background : Some of invasive plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plants in Korea, particularly in Jeju Island, invade farmland, and autochthonous forest, establishing monocultures and modifying the ecosystem structure. This invasive species has become a serious environmental problem because they displace the indigenous plant species. This study was conducted to evaluate the antioxidantive effects of ethanolic extracts from different parts (root, stem, seed and leaf) of the invasive exotic species Hypochaeris radicata L. Methods and Results : The aim of present study was to estimate the total phenolic and flavonoid contents and to investigate in vitro antioxidant potential of ethanolic leaf, root, seed, and stem extracts of the Hypochaeris radicata. Antioxidant activity was assessed by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, reducing power activity, [2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] ABTS+ assay and ferrous ion chelating activity. The total phenolic and flavonoid contents were also determined and expressed in gallic acid and quercetin equivalent respectively. The results of the study indicate that the ethanolic extracts of the leaf, root, seed, and stem of H. radicata posses significant scavenging activity against DPPH (21.25% for leaf, 34.98% for root, 60.76% for seed and 45.25% for stem at 250 μg/ml each) and ABTS+ radical scavenging activity (14.85% for leaf, 17.40% for root, 35.91% for seed and 24.70% for stem at 250 μg/ml each), reducing power activity (0.178 absorbance at 300 μg/ml for leaf, 0.211 absorbance at 300 μg/ml for root, 0.447 absorbance at 300 μg/ml for seed, 0.276 absorbance at 300 μg/ml for stem). The free radical scavenging and antioxidant activities may be attributed to the presence of adequate phenolic (gallic acid content is 361.92.98 μg/g in leaf, 356.59μg/g in root, 719.72 μg/g in seed and 512.08 μg/g stem) and flavonoid compounds (219.52 μg/g in leaf, 75.67μg/g in root, 281.39 μg/g in seed and 215.66 μg/g stem). This study revealed that the ethanolic extracts of both leaf, root, seed and stem of H. radicata has demonstrated significant antioxidant activity. Conclusion : In conclusion, the present study has demonstrated that Hypochaeris radicata seed ethanol extracts are rich in phenolics and have a strong antioxidant activity and a radical-scavenging action in all of the tested methods. This suggests that Hypochaeris radicata is a good source of natural antioxidants.
        137.
        2016.10 서비스 종료(열람 제한)
        Background : Malonyl ginsenoside content of the Panax ginseng is known to account for 35% to 60% of total ginsenosides content. However, its distribution by ginseng part has not been studied. In this study, four kinds of malonyl ginsenosides were compared in Korean white ginseng part using the purified malonyl ginsenoside standards in our laboratory. Methods and Results : White ginseng was prepared by the air drying (50℃, 48h) or freeze drying (-70℃, 48h) methods form 4-year-old ginseng. Malonyl ginsenoside content in total ginsenosides were similar in air dried and freeze dried white ginseng, 58% and 62%, respectively. Therefore, malonyl ginsenoside contents in main, lateral, and fine root, and in the main root without skin and skin of main root prepared by freeze dried method were compared. Malonyl ginsenosides (m-Rb1, m-Rb2, m-Rc and m-Rd) and total ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3, Rd, m-Rb1, m-Rb2, m-Rc and m-Rd) were 6.75 and 14.15 mg/g in main root, 14.15 and 26.35 mg/g in lateral root, 46.95 and 84.15 mg/g in fine root. Malonyl ginsenoside contents in skin of main root was 20.08 mg/g, while its contents of the main root without skin was 2.58 mg/g. Conclusion : As a result, the parts each air drying the sample was confirmed that the ratio of the distribution of malonyl ginsenoside (main root : lateral : fine root = 18.7 : 11.1 : 16.2), and distribution ratio of main root, skin of main root, lateral, skin of lateral was found to be (12.2: 14.6 14.3: 3.7). Malonyl ginsenoside content was the highest in fine root, compared to the main or lateral root. Malonyl ginsenoside contents in skin of root was higher than those of the main root without skin. These results is expected to help establish an efficient extraction and standardization. Malonyl ginsenoside analysis of White ginseng using HPLC expects that the standardization process can be established.
        138.
        2016.05 서비스 종료(열람 제한)
        Background : Plants of Taraxacum spp. are widely used in medicine, but some of them have some problems related to propagation, such as strong dormancy and inactive germination. This study investigated the effects of temperature, gibberellic acid (GA3), and potassium nitrate (KNO3) on seed germination in Taraxacum ohwianum. Methods and Results : The seeds (NIBRGR0000135524) were exalbuminous, and their length and width were 4.25 ± 0.118 mm and 0.89 ± 0.062 mm, respectively. Among various temperatures (15, 20, 25, and 30℃), the optimum temperature for germination was found to be 20℃ (31.3%). High temperature (30℃) induced off-type in seedlings (thickened and crumpled cotyledons, and restricted root system). GA3 treatments increased germination percentage and speed, but germination percentage was higher with KNO3 treatment. Under KNO3 treatments (50 to 200 mg·L-1), germination percentage exceeded 80% after 12 days, with 50 mg·L-1 KNO3 being notably effective (91.2%, after 15 days). Conclusion : Seeds of T. ohwianum showed germination ability at low temperature. The best method for germination was pre-soaking in 50 mg·L-1 KNO3 (4℃, dark, 24 h) and incubating at 20℃ for 15 days.
        139.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The purpose of this study was to determine the optimum amount of Artemisia annua L. powder for adding rice flour. The A. annua powder was added to the rice flour at ratios of 1% (30 g/3 kg), 2% (60 g/3 kg), 3% (90 g/3 kg, w/w). As the amount of A. annua powder in rice cake dough increased, carbohydrate, ash content, total amino acid, and dietary fiber contents increased whereas the moisture content decreased. Hunter’s L value decreased as A. annua powder content increased. On the contrary, the a- and b values increased. The sensory score of the rice cakes containing 30 g of A. annua powder was the highest of all the rice cakes tested. Based on these results, adding A. annua powder could improve the quality and sensory characteristics of rice cake.