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        검색결과 984

        361.
        2016.04 구독 인증기관·개인회원 무료
        It is difficult to identification between Bursaphelenchus spp. and Pine Wood Nematode (PWN) by morphological characteristics without expertise about nematode taxonomy. Furthermore, Baermann funnel method, which is nematode extraction method from wood chips or soil, requires at least 24 hours to extract nematode that is unsuitable to rapid diagnose the Pine Wilt Disease (PWD). For these reasons, the aim of this experiment is not only to improve accuracy of a PCR based method but also to reduce total experiment time for detection Bursaphelenchus spp. and PWN in the wood chips of PWD infected pine tree. In this experiment, we had been employed two PCR primer sets, which were originated from PWN specific Internal Transcribed Spacer (ITS) sequence region and Bursaphenchus spp. universal mitochondrial Cytocrome Oxidase subunit I (mtCOI) sequence region in order to discrimination between Bursaphelenchus spp. and PWN at the same PCR reaction. This experimental procedure was able to reduce experiment time and cost as well as to improve accuracy of detection than previous PCR based detecting method by not using Baermann funnel method and commercial genomic DNA extraction kit but using direct pine wood chips lysis method.
        362.
        2016.04 구독 인증기관·개인회원 무료
        The first record of Melon thrips, Thrips palmi Karny, was in 1993 in Korea, and the species has become severe pest in agricultural industry. We used two different SDMs(Species Distribution Model) which have different approaches to analyse potential distribution of the pest species in climate change scenario, MaxEnt and CLIMEX. The MaxEnt model uses historical occurrence records with environmental variables to estimate the realized niche, and CLIMEX model simulates the fundamental niche of the object based on the seasonal phenology. In MaxEnt simulation, we reduced the number of variables to avoid multi-collinearity problem until we had no pairs with an absolute Pearson correlation coefficient higher than 0.8. BIO1(Annual Mean Temperature), BIO2(Mean diurnal range), BIO3(Isothermality), BIO4(Temperature seasonality) were finally selected as predictor, and we used 10 fold cross validation option to replicate. The averaged results were used to index analysis. The CLIMEX results, The Ecoclimate Index(EI), were also normalized in 0 to 1 scale to analysis. Under RCP 8.5 climate change scenario, in 2070s, the distribution of Thrips palmi was predicted to expand their territory overall agricultural area in Korea.
        364.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Global warming is considered one of the great challenges of the twenty-first century. In order to reduce the ever-increasing amount of methane (CH4) released into the atmosphere, and thus its impact on global climate change, CH4 storage technologies are attracting significant research interest. CH4 storage processes are attracting technological interest, and methane is being applied as an alternative fuel for vehicles. CH4 storage involves many technologies, among which, adsorption processes such as processes using porous adsorbents are regarded as an important green and economic technology. It is very important to develop highly efficient adsorbents to realize techno-economic systems for CH4 adsorption and storage. In this review, we summarize the nanomaterials being used for CH4 adsorption, which are divided into non-carbonaceous (e.g., zeolites, metal-organic frameworks, and porous polymers) and carbonaceous materials (e.g., activated carbons, ordered porous carbons, and activated carbon fibers), with a focus on recent research.
        4,200원
        365.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, with continuous developments in the field of materials science, graphene oxide (GO) has emerged as a promising material with excellent electrical, thermal, mechanical, and optical properties, which play important roles in most fields. Researchers have achieved considerable progress with graphene. Chitosan (CS) is a natural polymer that has been studied intensively owing to its specific formation, high chemical resistance, and excellent physical properties. These outstanding properties have led to its universal use in applications such as textile fabrics, tissue engineering, medicine and health, coatings, and paints. By combining the advantages of GO and CS, different types of promising materials can be obtained. This review discusses the preparation of GO-CS fibers, hydrogel and aerogel, and the applications of GO-CS nanocomposites. In addition, directions for future research on graphene material composites are discussed.
        4,000원
        366.
        2016.03 구독 인증기관 무료, 개인회원 유료
        OSCC is currently the most common malignancy of the head and neck, affecting tens of thousands of patients per year worldwide. Natural flavonoids from plants are potential sources for novel anti-cancer drugs. Icariin is the active ingredient of flavonol glycoside, which is derived from the medical plant Herba Epimedii. A metabolite of icariin, icariside II exhibits a variety of pharmacological actions, including anti-rheumatic, anti-depressant, cardiovascular protective, and immunomodulatory functions. However, the exact mechanism causing the apoptosis-inducing effect of icariside II in OSCC is still not fully understood. In the present study, we assessed the anti-cancer effect of icariside II in OSCC cell lines by measuring its effect on cell viability, cell proliferation, and mitochondria membrane potential (MMP). Icariside II treatment of OSCC cells resulted in a dose- and time-dependent decrease in cell viability. Hoechst staining indicated apoptosis in icariside II-treated HSC cells. Icariside II inhibited cell proliferation and induced apoptosis in HSC cells, with significant increases in all present parameters in HSC-4 cells. The results clearly suggested that icariside II induced apoptosis via activation of intrinsic pathways and caspase cascades in HSC-4 cell lines. The collective findings of the study suggested that Icariside II is a potential treatment for OSCC; in addition, the data could provide a basis for the development of a novel anti-cancer strategy.
        4,000원
        367.
        2016.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Multiple color selection techniques are successful in identifying quasars from wide-field broad- band imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at 5 . z . 5.7 due to the limitations of filter sets in previous studies. In this work, we present a new selection technique of high redshift quasars using a sequence of medium-band filters: nine filters with central wavelengths from 625 to 1025 nm and bandwidths of 50 nm. Photometry with these medium-bands traces the spectral energy distribution (SED) of a source, similar to spectroscopy with resolution R  15. By conducting medium-band observations of high redshift quasars at 4.7  z  6.0 and brown dwarfs (the main contaminants in high redshift quasar selection) using the SED camera for QUasars in EArly uNiverse (SQUEAN) on the 2.1-m telescope at the McDonald Observatory, we show that these medium-band filters are superior to multi-color broad-band color section in separating high redshift quasars from brown dwarfs. In addition, we show that redshifts of high redshift quasars can be determined to an accuracy of z/(1 + z) = 0.002 – 0.026. The selection technique can be extended to z  7, suggesting that the medium-band observation can be powerful in identifying quasars even at the re-ionization epoch.
        4,200원
        368.
        2015.11 구독 인증기관·개인회원 무료
        The aim of this study was to identify and characterize new Flammulina velutipes laccases from its whole-genome sequence. Of the 15 putative laccase genes detected in the F. velutipes genome, four new laccase genes (fvLac-1, fvLac-2, fvLac3, and fvLac-4) were found to contain four complete copper-binding regions (ten histidine residues and one cysteine residue) and four cysteine residues involved in forming disulfide bridges. fvLac-1, fvLac-2, fvLac3, and fvLac-4, encoding proteins consisting of 516, 518, 515, and 533 amino acid residues, respectively. Potential N-glycosylationsites(Asn-Xaa-Ser/Thr) were identified in the cDNA sequence of fvLac-1(Asn-454), fvLac-2(Asn- 437andAsn-455), fvLac-3(Asn-111andAsn-237), and fvLac4 (Asn-402andAsn-457). In addition, the first 19–20 amino acid residues of these proteins were predicted to comprise signal peptides. Laccase activity assays and reverse transcription polymerase chain reaction(RT-PCR) analyses clearly reveal that CuSO4 affects the induction and the transcription level of these laccase genes.
        373.
        2015.10 구독 인증기관·개인회원 무료
        Butterflies are commonly used for environmental monitoring to assess biodiversity changes in the world. Occurrence of butterflies were monitored by a line transect method in Gwangneung forest for 10 years from 2005 to 2014. Totally, 8,484 individuals of 96 species of butterflies were identified. Among them, two species Libythea celtis (2807 individuals) and Pieris melete (1517 individuals) were the most abundant species, followed by Argynnis paphia (381 individuals) and Neptis philyroides (277 individuals). Meanwhile, Pieris melete and Libythea celtis showed high occurrence frequency with 84.6% (99 times among the 117 monitoring times) and 76.9% (90 times) respectively, followed by Argynnis paphia (42.7%) and Pieris canidia (40.2%). Species richness and abundance were varied at different years, and they were slightly decreasing in recent years. Most species showed annual variation in their abundance. Species abundance distribution model showed a log-normal distribution.
        374.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted from October 2014 to May 2015 to explore forage production and feed values of Italian ryegrass, Rye and whole crop barley as winter forage crops in the Southern region of Korea. The experimental location was over 10 points for each species and each sampling point area was 1 m² (Width: 1 m × Length: 1 m). Air mean temperature and rainfall in the Southern region of Korea during the experimental period was 6.95 ± 5.75℃ and 70.45 ± 54.68 mm, respectively. Fresh forage yield of Italian ryegrass, the most cultivated forage in the Southern region of Korea, was 44.4 ± 7.0 ton/ha. The percentage of dry matter for whole crop barley was 28.9 ± 7.0%. Crude protein (CP) was higher in Italian ryegrass (10.7 ± 5.3%) while total digestible nutrient (TDN) had the highest value in whole crop barley. Crude protein was not significantly different by location. However, the neutral detergent fiber (NDF), acid detergent fiber (ADF) and total digestible nutrient value of forage from Jeonbuk province were higher than in forage from Gyeongnam province.
        4,000원
        375.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Korean National Residue Program (KNRP) use three plans for the sampling of domestic meats: monitoring, surveillance, and exploratory testing. We analyzed the results of monitoring and surveillance for residual veterinary drugs and pesticides in meat during 2012 and 2013. KNRP targets food-producing animals including cattle, pigs, chickens, ducks, sheep (goats), and horses. Sampling mainly focuses on veterinary drugs and pesticide residues found in tissues such as muscle, kidney, and liver. A total of 548 residue violations occurred between 2012 and 2013, mainly in pigs (427 violations) and cattle (113 violations). The most commonly found compounds were antimicrobials such as penicillins, fluoroquinolones, aminoglycosides, tetracyclines, sulfonamides, and macrolides. Pig residue violations were mainly for the presence of penicillins (34%) and fluoroquinolones (28%), while most residue violations in cattle were due to the presence of penicillins (32%) and aminoglycosides (27%). The overall rates of violations were 0.21% in 2012 and 0.10% in 2013. A major cause of violations was the failure to follow the appropriate withdrawal periods (68.8%). The results of the KNRP were analyzed to provide information on agricultural chemical residues that are of public health concern and to help control and prevent residue violations for ensuring food safety.
        4,000원
        376.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FMB1), ochratoxin A, T2 toxin, and zearalenone, are found in numerous vegetables. Mycotoxin accumulation in food and feed poses serious health risks to humans and animals because of carcinogenic, mutagenic, teratogenic, and toxic properties. In addition, mycotoxins cause large economic losses in commercial crop production, food and feed processing, and animal husbandry worldwide. In this study, an analytical method for the simultaneous analysis of the levels of AFB1, DON, and FMB1 in cow blood with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. AOZTM and Myco6in1TM multitoxin immunoaffinity columns and an OasisTM reversed-phase solid-phase extraction Hydrophilic-Lipophilic-Balanced columns were used to purify and concentrate the blood samples. Extracts that contained AFB1, DON, and FMB1 had average recovery of 64.0%, 98.0%, and 89.9%, respectively. In conclusion, we used LC-MS/MS to detect several important toxicological mycotoxins in cow blood. The multimycotoxin method, which detected and quantified the levels of AFB1, DON, and FMB1 can be used in animal pilot studies to monitor simultaneous exposure to major mycotoxins.
        4,000원
        377.
        2015.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to study the impact of atmosphere during electron beam irradiation (EBI) of polyacrylonitrile (PAN) precursor fibers, the latter were stabilized by EBI in both air and oxygen atmospheres. Gel-fraction determination indicated that EBI-stabilization under an oxygen atmosphere leads to an enhanced cyclization in the PAN fibers. In the Fourier-transform infrared spectroscopy analysis, the PAN fibers stabilized by EBI under an oxygen atmosphere exhibited a greater decrease in the peak intensity at 2244 cm-1 (C≡N vibration) and a greater increase in the peak intensity at 1628 cm-1 (C=N absorption) than the corresponding PAN fibers stabilized under an air atmosphere. From the X-ray diffraction analysis it was found that oxygen uptake in PAN fibers leads to an increase in the amorphous region, produced by cyclization.
        3,000원
        378.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Quercetin is a natural flavonoid phytochemical that is extracted from various plants. Having an advantages due to its varied biological properties, such as anti-inflammatory, anti-viral, anti-oxidant, and anti-cancer effects, quercetin is used to treat many diseases. Recently, it has been reported that autophagy inhibition may play a key role in anti-cancer therapy. Therefore, in this study, we investigated the molecular mechanisms and anti-cancer effects of quercetin in human osteosarcoma cells via autophagy inhibition. We ascertained that quercetin inhibited cell proliferation and induced cell death, these process is demonstrated that apoptosis via the mitochondrial pathway and the caspase cascade. Quercetin also induced autophagy which was inhibited by 3-MA, autophagy inhibitor and the blockade of autophagy promoted the quercetin-induced apoptosis, confirming that autophagy is a pro-survival process. Thus, these findings demonstrate that quercetin is an effective anti-cancer agent, and the combination of quercetin and an autophagy inhibitor should enhance the effect of anti-cancer therapy.
        4,000원
        379.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to find out the effect of water stress (RDI) on multiplication of plant parasitic nematodes on grapevines. The responses to irrigation treatments were not significantly different in relation to new root growth, root dry weight and total number of parasitic nematodes, however significant differences in the density of Meloidogyne javanica in the soil between daily irrigation and the treatment with water stress (RDI). The main effect of inoculum type was significant, and the water treatments significantly affected total root growth between the nematode treatments, as well as M. javanica density in the soil in the nematode treatments. The daily irrigation treatment with Pratylenchus spp. had the least root growth but was not significantly different to root growth in the RDI treatment with Pratylenchus spp. Similarly with RDI, there was no significant difference in root growth in treatments receiving combined nematode inoculum between daily irrigation and RDI. However, root growth in treatments receiving M. javanica in RDI was significantly greater than those receiving M. javanica with daily irrigation. Under RDI treatment, the number of M. javanica recovered from soil receiving M. javanica inoculum was significantly greater than under daily irrigation. However, there was no significant difference between daily irrigation and RDI in the number of M. javanica or Pratylenchus recovered from soil receiving the combined treatment or in Pratylenchus recovered from soil in the Pratylenchus treatment.
        4,000원
        380.
        2015.05 구독 인증기관 무료, 개인회원 유료
        The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for Ca2+, releases Ca2+ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.
        4,000원