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        검색결과 83

        21.
        2018.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Salvia miltiorrhiza (Danshen) is perennial plant and commonly used in traditional Chinese medicine to treat numerous diseases like cardiovascular and cerebrovascular diseases, coronary heart disease, myocardial infarction, stroke and some viral diseases. Nevertheless, no study has been conducted on the antiviral properties of crude extract of Salvia miltiorrhiza against Influenza virus. In an attempt to identify new potential anti-influenza virus agents, 200 natural oriental herbal medicines were screened and we found that Salvia miltiorrhiza has a potential anti-influenza effect. Therefore, in this study, we investigated the protective effect of aqueous extract from Salvia miltiorrhiza against divergent influenza A subtypes using murine model of influenza A infection. Effective dose of aqueous extracts of Salvia miltiorrhiza in BALB/c mice displayed higher survival rate and lower lung viral titers when challenged with lethal doses of influenza A subtypes ({A/Aquatic bird/Korea/ W81/2005(H5N2)}, {A/PR/8/34(H1N1)}, {A/Aquatic bird/Korea/W44/2005(H7N3)} and {A/Chicken/ Korea/116/2004(H9N2)}). In vivo results exhibited that Salvia miltiorrhiza induced prophylactic effect in BALB/c mice against Influenza virus by disrupting viral replication or preventing viral infection by creating an antiviral state in the lungs. Taken together, the use of aqueous extracts of Salvia miltiorrhiza as an orally active antiviral agent, will be potential candidates for prophylactic treatments against Influenza A virus for humans and animals.
        4,000원
        22.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Near infrared spectroscopy (NIRS) is a rapid and accurate method for analyzing the quality of cereals, and dried animal forage. However, one limitation of this method is its inability to measure fermentation parameters in dried and ground samples because they are volatile, and therefore, respectively lost during the drying process. In order to overcome this limitation, in this study, fresh coarse haylage was used to test the potential of NIRS to accurately determine chemical composition and fermentation parameters. Fresh coarse Italian ryegrass haylage samples were scanned at 1 nm intervals over a wavelength range of 680 to 2500 nm, and optical data were recorded as log 1/reflectance. Spectral data, together with first- and second-order derivatives, were analyzed using partial least squares (PLS) multivariate regressions; scatter correction procedures (standard normal variate and detrend) were used in order to reduce the effect of extraneous noise. Optimum calibrations were selected based on their low standard error of cross validation (SECV) values. Further, ratio of performance deviation, obtained by dividing the standard deviation of reference values by SECV values, was used to evaluate the reliability of predictive models. Our results showed that the NIRS method can predict chemical constituents accurately (correlation coefficient of cross validation, R2 cv, ranged from 0.76 to 0.97); the exception to this result was crude ash (R2 cv = 0.49 and RPD = 2.09). Comparison of mathematical treatments for raw spectra showed that second-order derivatives yielded better predictions than first-order derivatives. The best mathematical treatment for DM, ADF, and NDF, respectively was 2, 16, 16, whereas the best mathematical treatment for CP and crude ash, respectively was 2, 8, 8. The calibration models for fermentation parameters had low predictive accuracy for acetic, propionic, and butyric acids (RPD < 2.5). However, pH, and lactic and total acids were predicted with considerable accuracy (R2 cv 0.73 to 0.78; RPD values exceeded 2.5), and the best mathematical treatment for them was 1, 8, 8. Our findings show that, when fresh haylage is used, NIRS-based calibrations are reliable for the prediction of haylage characteristics, and therefore useful for the assessment of the forage quality.
        4,000원
        23.
        2017.04 구독 인증기관·개인회원 무료
        Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.
        24.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Vinca alkaloids from plant Vinca minor have been investigated for their effects of tyrosinase inhibition, stimulation of ROS generation and increasement of cell migration activity. The methanolic crude extract and the water-soluble fraction exhibited IC50 value of 3.1 mg/mL and 2.1 mg/mL. Vinca minor extract treatment significantly increased ROS levels in HaCaT cells, in a concentration-dependent manner. Treatments of Vinca minor extract led to increase wound closure when compared with non-treatment. Low dose (0.1% or 0.3%) of extracts have not significantly affected, compared with that in controls. By contrast, 0.5% extract have dramatic effect on wound healing activity of keratinocytes. Effects of Vinca minor extract in a filter-based cell mobility assay appear similar to that of wound closure assay, which suggests that the Vinca minor extract have wound healing effects on skin.
        4,000원
        25.
        2016.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present analyses of 1250 variable sources identi ed in a 20 square degree eld toward NGC 2784 by the KMTNet Supernova Program. We categorize the variable sources into three groups based on their B-band variability. The rst group consists of 31 high variability sources with their B- band RMS variability greater than 0.3 magnitudes. The second group of medium variability contains 265 sources with RMS variability between 0.05 and 0.3 magnitudes. The remaining 951 sources belong to the third group of low variability with an RMS variability smaller than 0.05 magnitudes. Of the entire 1250 sources, 4 clearly show periods of variability greater than 100 days, while the rest have periods shorter than 51 days or no reliable periods. The majority of the sources show either rather irregular variability or short periods faster than 2 days. Most of the sources with reliable period determination between 2 and 51 days belong to the low-variability group, although a few belong to the medium-variability group. All the variable sources with periods longer than 35 days appear to be very red with B􀀀V > 1.5 and V 􀀀I > 2.1 magnitudes. We classify candidates of 51 Cepheids, 17 semi-regular variables, 3 Mira types, 2 RV(B) Tauri stars, 26 eclipsing binary systems and 1 active galactic nucleus. The majority of long-term variables in our sample belong to either Mira or semi-regular types, indicating that long-term variability may be more prominent in post-main sequence phases of late-type stars. The depth of the eclipsing dips of the 26 candidates for eclipsing binaries is equivalent to 0.61 as the average relative size of the two stars in the binary system. Our results illustrate the power of the KMTNet Supernova Program for future studies of variable objects.
        4,800원
        30.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, temperature variation characteristics in a flat plate with sheath heater are investigated through experiment and numerical analysis. ANSYS fluent is used to calculate the temperature distribution in the heating plate system. Transient condition is applied to observe temperature variation with the sheath heater operation, and thermal resistance on the contacted surfaces is also considered. Experimental data agree well with numerical results obtained for heat generation rate from sheath heater, Local temperature variation on the surface of flat plate is also predicted through this simulation. There is large temperature variation in the air surrounded flat plate, especially at the top of flat plate with natural convective heat transfer. These results will be helpful in optimal design for various systems equipped with sheath heater.
        4,000원
        31.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The camera embedded wall climbing robot in this paper combines the suction and aerodynamic attraction to achieve good balance between strong adhesion force and high mobility and adopts embedded image processing technique to detect targets on the warehouse inspection. Experimental results showed that the robot can move upward on the wall at the speed of 2.9m/min and carry 5kg payload in addition to 2.5kg self-weight, which record the highest payload capacity among climbing robots of similar size. With two 11.1V lithium-polymer battery, the robot can operate continuously for half hours. A wireless camera system, zigbee protocol module and several sensors was adopted for detecting target objects and dangerous situation on the wall and for sending alarm signals to remote sensor node or manager.
        4,000원
        32.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was initiated to investigate antioxidant, anti-acetylcholinesterase, and xanthine oxidase inhibitory activities and properties of fruiting bodies, mycelia, and fermentation culture filtrates from Phellinus igniarius. The contents of total phenols and flavonoid of fruit bodies, mycelia, and culture filtrate were 15.35-1.36 mg/g, 10.35-7.85 mg/g, and 8.25-5.36 mg/g. The 1,1- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging abilities of the extracts from the fruiting bodies, mycelia, and culture filtrates were 90.25-95.60%, 78.82-85.24%, and 76.32-82.50% at 50-400 μg/mL, respectively. The chelating ability of fruiting body extract on ferrous ions was higher than those of mycelia and culture filtrates tested. The anti-acetylcholinesterase inhibitory activity of the fruiting body extract at 400 μg/mg exhibited 91.10% on AChE, which is lower than that of positive control, galanthamine (94.82%). The xanthine oxidase inhibitory activities of the fruiting bodies, mycelia, and culture extract were 85.47%, 78.13%, and 72.49% at 400 μg/mL, respectively. Overall, the fruiting body extract has better anti-acetylcholinesterase, antioxidant and xanthine oxidase inhibitory activities than those from mycelia and culture filtrate.
        4,000원
        33.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyporus umbellatus (Syn. Grifola umbellata) is a sclerotium forming mushroom belongs to family Poly-poraceae of Polyphorales, Basidiomycota. The sclerotia of P. umbellatus have long been used for traditional medicinesin China, Korea and Japan. This study was initiated to obtain the basic data for artificial sclerotial production of P. umbel-latus. Here, we investigated the favorable conditions for mycelial growth of P. umbellatus and its symbiotic fungus Armill-aria mellea. We also evaluate the favorable carbon and nitrogen sources for sclerotial formation in dual culture betweenP. umbellatus and A. mellea. The favorable conditions for mycelial growth of P. umbellatus were 20°C and pH 4, whileoptimal conditions for mycelial growth of A. mellea were 25°C and pH 6. The carbon sources for optimal mycelial growthof P. umbellatus were fructose and glucose, while carbon sources for favorable mycelial growth of A. mellea were alsofructose and glucose. The nitrogen sources for favorable mycelial growth P. umbellatus were peptone and yeast extract,while optimal mycelial growth of A. mellea were obtained in peptone and yeast extract. When P. umbellatus and A. melleawere dual cultured on carbon sources, sclerotia were induced on basal media supplemented with glucose, fructose andmaltose at pH 4~6, while nitrogen sources inducing sclerotia were basal media supplemented with peptone and yeastextract for 60 days at 20°C under dark condition.
        4,000원
        34.
        2013.10 구독 인증기관·개인회원 무료
        Most traditional genome sequencing projects involving infectious viruses include culturing and purification of the virus. This can present difficulties as an analysis of multiple populations from multiple locations may be required to acquire sufficient amount of high-quality DNA for sequence analysis. The electrophoretic method provides a strategy whereby the genomic DNA sequences of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) were analyzed by purifying it from host DNA by pulsed-field gel electrophoresis, thus simplifying sampling and labor time. The genomic DNA of infected P. rapae was embedded in agarose plugs, digested with a restriction nuclease and methylase, and pulsed-field gel electrophoresis (PFGE) was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the separated viral DNA. The double-stranded circular genome of PiraGV-K encodes 120 open reading frames (ORFs), covering 92% of the sequenced genome. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF11), involved in the liquefaction of the host, were found in the genome. The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the pulsed field electrophoretic method. The method appears to be applicable to the analysis of genomes of large viruses. The chitinase, identified by PiraGV-K genome sequence, was functionally characterized by quantitative PCR, Western blot analysis, immunohistochemistry and transmission electron microscopy.
        39.
        2011.03 구독 인증기관 무료, 개인회원 유료
        To investigate the effect of carnosine on exhaustive exercise, swimming tests were conducted weekly with loads corresponding to 5% of body weight attached to the tails of mice, and the swimming time to exhaustion was measured. Eighty male ICR mice were divided into four groups, to which carnosine was administered at doses of 0 (control), 10, 50, and 250 mg/kg/day, respectively, for a period of four weeks. At the end of swimming exercise challenges, serum biochemistry, oxidative stress enzyme activity, and antioxidant enzyme activity in tissues were determined. Treatment with 250 mg/kg carnosine resulted in a significant increase in swimming times to exhaustion, compared to the control group in the first (P<0.01) and third week (P<0.05). Significantly lower serum lactate levels were observed after the swimming exercise in the carnosine-treated groups (10 and 250 mg/kg), compared with the control (P<0.01). Malondialdehyde levels in the liver (10 and 50 mg/kg carnosine treated groups) and skeletal muscle (250 mg/kg carnosine treated group) were significantly lower, compared with the control (P<0.05). Significantly lower protein carbonyl levels in skeletal muscle were observed in the 50 and 250 mg/kg carnosine treated groups, compared with the control (P<0.01). Superoxide dismutase and glutathione peroxidase activities in skeletal muscle did not differ significantly among the groups. These results indicate that carnosine may improve swimming exercise capacity by attenuating production of lactate and reducing oxidative stress in mice.
        4,300원
        40.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        Lentinus lepideus is an edible mushroom, belongs to the family Tricholomaceteae and order Agaricales. The purpose of this study was to evaluate the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of L. lepideus extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and ferrous chelating abilities. In addition to this, phenolic acid and flavonoids contents were also analyzed. Hot water extract of L. lepideus showed the strongest β-carotene-linoleic acid inhibition as compare to others extracts. At 8 mg/ml, methanolic extract showed a high reducing power of 1.21. The scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals, acetonic and methanolic extracts were effective than hot water extract. The strongest chelating effect (87.50%) was obtained from the methanolic extract at 1.0 mg/ml concentration. Antioxidant activities of the extracts from the fruiting bodies of L. lepideus were increased with the increasing concentration. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, six phenolic compounds namely, chlorogenic acid, vanillin, naringin, naringenin, formononetin and biochanin were identified from acetonic extract. Tyrosinase inhibition of acetonic, methanolic, and hot water extracts of L. lepideus were increased with the increasing of concentration. Results revealed that acetonic and methanolic extract showed good, while hot water showed moderate activities of the tyrosinase inhibition at the concentration tested. This study suggests that fruiting bodies of L. lepideus can potentially be used as a readily accessible source of natural antioxidants.
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