검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 497

        241.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Isotropic pitch fibers were stabilized and carbonized for preparing carbon fibers. To optimize the duration and temperature during the stabilization process, a thermogravimetric analysis was conducted. Stabilized fibers were carbonized at 1000, 1500, and 2000℃ in a furnace under a nitrogen atmosphere. An elemental analysis confirmed that the carbon content increased with an increase in the carbonization temperature. Although short graphitic-like layers were observed with carbon fibers heat-treated at 1500 and 2000℃, Raman spectroscopy and X-ray diffraction revealed no significant effect of the carbonization temperature on the crystalline structure of the carbon fibers, indicating the limit of developing an ordered structure of isotropic pitch-based carbon fibers. The electrical conductivity of the carbonized fiber reached 3.9×10⁴S/m with the carbonization temperature increasing to 2000℃ using a four-point method.
        4,000원
        242.
        2013.05 구독 인증기관 무료, 개인회원 유료
        Smart phones have drastically changed the life of today’s competitive world. Smart phone application (App) developers are trying their best to meet the customer requirements in the most efficient way while considering all its attributes. However smart phone service quality has been given less consideration comparatively during the last few years. This paper proposes a measurement method for improving service quality of smart phone application. This method combines the service quality performance model and process capability index. The service quality performance model is used to identify service items that require improvement. Process capability index is used to prioritize these items for improvement. We collected data on satisfaction level of customers who have used application service. By the proposed method, we found five significant service items from three categories - execution, security and resilience and prioritized those items for improvement.
        4,000원
        243.
        2013.04 구독 인증기관·개인회원 무료
        The oriental tobacco budworm, Helicoverpa assulta, is an oligophagous insect feeding on a few species of Solanaceae plants, including Nicotina tabacum. This study investigated the relationship between H. assulta and plants, focusing on oviposition preference and larval performance of the specialist in host and non-host plants. (1) In choice experiments, N. tabacum and Phaseolus vulgaris were put in a cage with 5 females and 10 males. Most of eggs (ca. 98%) were layed in N. tabacum, whereas few eggs in P. vulgaris. (2) In non-choice experiments, N. tabacum, Datura stramonium, or P. vulgaris was individually put in a cage with 3 females and 6 males, resulting that N. tabacum was the most preferred host, followed by D. stramonium and P. vulgaris. Oviposition was delayed about 2 days in P. vulgaris (a non-host plant) compared to the two host plants. (3) Larval performances were also compared with the three plants. Larval growth was better in N. tabacum followed by D. stramonium and P. vulgaris, High mortality (ca. 100%) of larvae was observed in P. vulgaris, suggesting toxic component(s) derived from the non-host plant might cause the death. The ovipositional avoidance in P. vulgaris is current being investigated to search for the oviposition deterrent, which could be useful for the environment-friendly pest management of H. assulta.
        244.
        2013.04 구독 인증기관·개인회원 무료
        Cotesia plutellae has been known as a natural enemy against the Diamondback moth, Plutella xylostella via laying eggs into a larva. When the larva hatches from the egg, teratocytes also are released and expected to work as immune suppressor via secreting immune suppressive factors. In order to analyze the gene expression in teratocytes, total RNAs were isolated and genes expressed in the teratocyte were sequenced by Illumina HiSeq2000 RNASeq analysis. The information on RNA sequences was assembled by Trinity and contigs were annotated by Blast analysis. The levels of gene expression were calculated by FPKM. Approximately, 6.3 Gbs were obtained and 34,686 contigs were found and annotated. Forty two percent of contigs were homologous to previously reported genes and classified by gene ontologies: the highly abundant components are metabolic process, biological regulation and cellular process in biological function; binding, catalytic activity and transporter activity in molecular function; cell part, membrane part and organelle in cellular function, respectively. In addition, some teratocyte transcripts of C. plutellae are related to host regulation such as immunosuppression and nutrition: Ankyrin repeat proteins, Serpin, protease, lipase, chitinase and scavenger receptor.
        245.
        2013.04 구독 인증기관·개인회원 무료
        An assessment was made of the toxicity of hiba, Thujopsis dolabrata var. hondai, oil and 24 oil constituents and control efficacy of four experimental spray formulations containing the oil (0.5. 1, 2, and 3% sprays) to adult American house dust mite (AHDM), Dermatophagoides farinae, and copra mite (CM), Tyrophagus putrescentiae. Results were compared with those of three conventional acaricides benzyl benzoate, N,N-diethyl-3-methylbenzamide (deet), and permethrin. Based on 24 h LC50 values, (–)-thujopsene was the most toxic constituent against AHDM (9.82 μg/cm2) and CM (10.92 μg/cm2) and the toxicity of the compound was nearly identical to that of benzyl benzoate (9.33 and 10.14 μg/cm2). High toxicity was also observed with (–)-(E)-pinocarveol, carvacrol, (+)-terpinen-4-ol, β-thujaplicin, cedrol, α-terpineol, (+)-ledene, thymol, and 2,4-di-tert-butylphenol against both mite species (LC50, 11.92–19.19 and 12.49–22.97 μg/cm2). These constituents were more toxic than deet (LC50, 35.53 and 38.42 μg/cm2). Hiba applied as 2 and 3% sprays provided >95% mortality against both mite species, whereas permethrin (cis:trans, 25:75) 2.5 g/L spray treatment resulted in ca 11% mortality. Global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments justify further studies on hiba oil preparations containing the constituents described as potential contact-action fumigants or lead molecules for the control of mite populations.
        246.
        2013.04 구독 인증기관·개인회원 무료
        The yellow fever mosquito, Aedes aegypti, is a vector for transmitting dengue fever and yellow fever. An assessment was made of the histopathological and molecular effects of pellitorine, an isobutylamide alkaloid, on third instar Ae. aegypti larvae. At 5 mg/L concentration of pellitorine, whole body of the treated larvae became dark in color, particularly damaged thorax and abdominal regions. Pellitorine targeted mainly on midgut epithelium and anal gills, indicating variably dramatic degenerative responses of the midgut through a sequential epithelial disorganization. The anterior and posterior midgut was entirely necrosed, bearing only gut lumen residues inside the peritrophic membranes. Pellitorine caused comprehensive damage of anal gill cells and branches of tracheole and the debris was found in hemolymph of anal gills. RT-PCR analysis indicates that the compound inhibited gene expression encoding V-type H+-ATPase and aquaporine 4 after treatment with 2.21 mg/L pellitorine. The results provide a fact that pellitorine merits further study as a potential larvicide with a specific target site or a lead molecule for the control of mosquito populations.
        247.
        2013.04 구독 인증기관·개인회원 무료
        The Diadegma fenestrale is known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. The Diadegma genus is reported to have symbiotic virus, ichnovirus, D. fenestrale Ichnovirus (DfIV) was identified from this species which is a first report. DfIV showed typical ichnovirus shape with two membranes surrounding the virus capsid. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total DfIV genomic DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical ichnovirus gene families were detected such as cys-motif, repeat element, vinnexin and vankyrin. Present study was focused on the gene expression patterns in two different lepidopteran hosts.
        248.
        2013.04 구독 인증기관·개인회원 무료
        One of the overlooked points in mosquito blood feeding research is a final step before blood feeding such as finding a best position of blood feeding site and blood vessels underneath. How mosquitoes detect blood vessels especially using chemosensory organs prior to a final stage of blood feeding is totally unknown. Here we provide the anatomical and chemosensory evidence that a piecing structure of the mouthpart of the mosquitoes is an essential apparatus for the penultimate stage in blood feeding in mosquitoes. Indeed, mosquito mouthparts possesses a set of olfactory receptor neurons in sensory hairs, which are sensitive to volatile compounds present in host blood. Furthermore, the inhibition of gene expression of these odorant receptors delayed blood feeding of the mosquito from host animals. Taken together, these results identify that chemosensory perception in mouthpart is involved in mosquito blood feeding behaviors, which in turn allows mosquito to locate a feeding site more precisely.
        249.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To evaluate the biological response of sea squirt Halocynthia roretzi with different body size to heavy metals and its suitability for ecotoxicity assays, the effects of Cr, Cu and Zn on its clearance and oxygen consumption rates were investigated. Clearance and oxygen consumption rates of H. roretzi with various body sizes were calculated at different metal concentrations. Both clearance and oxygen consumption rate were negatively correlated with body sizes. Clearance rate of H. roretzi decreased gradually with increasing concentration of heavy metal, the decreasing rate was in an order of Cr¤Cu¤Zn. The oxygen consumption rate first increased at low metal concentration (below 100 μg L-1) and then decreased rapidly with increasing metal concentrations. The decreasing rate was in an order of Cu¤Cr=Zn. There was a trend that the clearance rate and oxygen consumption rate decreased drastically under a concentration of 400 μg L-1, and then decreased smoothly when the metal ion concentration increased continually. So the oxygen consumption and clearance rate at a concentration of 400 μg L-1 Cu could be thought as a suitable biological tool for exotoxicology analysis.
        4,000원
        250.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to observe the fermentative quality and anthocyanin content in whole crop colored barley silage during storage periods and anthocyanin stability in in vitro ruminal fluid. Silages of colored barley cultivar “Boanchalbori” and normal barley cultivar “Yuyeonbori” were stored during 0, 2, 4, 6, and 12 months. The in vitro ruminal fluid was fermented for 0, 6, 12, 24, and 48 hrs. For the feed value, crude protein of colored barley silage was slightly increased in the silage compared to that of normal barley silage, and being increased up to 2 months after ensiling and thereafter maintained at the similar level. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of both the barley significantly increased by prolonged storage of 2 months (p<0.05), but they were maintained at the constant level after 2 months of storing silage. Whereas TDN (total digestible nutrients) contents of them were decreased by the prolonged storage of 2 months (p<0.05), then maintained at the constant levels. The fermentative quality and pH values in both the barley silages were slightly decreased during the storage time. Lactic acid and acetic acid contents were increased during prolonged storage period, but not significantly different among treatments. Butyric acid was not detected. In the colored barley silage, pH value showed slightly lower compared to that of the normal barley silage but not significant, and lactic acid content was significantly higher than the normal barley silage (p<0.05). The total anthocyanin content in the whole crop colored barley silage decreased to 42% after 2 months of ensilage, however maintained at the constant level until 12 months of ensilage. In the case of anthocyanin stability on in vitro ruminal fluid digestion, the pH value of the ruminal fluid was slightly lower at 6, 12, 24, 48h incubation time and the content of anthocyanin was at similar levels. These results indicated that the colored barley showed higher fermentation quality, and total anthocyanin content was maintained stable at 42% level of the first value in storing silage. As the anthocyanin had higher stability in the ruminal fluid, the colored barley has a potential as functional feeds for Ruminants.
        4,000원
        251.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to analyze the correlation between the stature and the muscle performance ratings and the subjective discomfort rations at performing lower arm's pronation and supination according to change sin the height of working table for more efficient performance at designing a working table and performing a work. For the purpose, this study conducted an experiment targeting 40 people in their 20s, who were classified into 4 groups each group composing 10 people at intervals of 5cm from the standard stature of 166.5cm. The experiment measured the maximum isometric pronation and the supination muscular power, and at measuring the factors, the heights of working tables were set as 800mm, 850mm, and 900mm. From the measurement results, it was found that the stature and the maximum muscular power was correlated. That is, as the experiment groups's average stature is higher, the maximum muscular power was higher. For the correlation between the motion patterns(pronation and supination) and the maximum muscular power, it was seen that the maximum muscular power was higher at performing the pronation than the supination. In the correlation between motion patterns and the subjective discomfort ratings, it was seen that the subjective discomfort rating was higher at performing the supination than the pronation. For the correlation between height adjustment and the subjective discomfort ratings, as the height of working table was lower, the subject discomfort rating was lower. Therefore there was no difference in the maximum muscular power according to the height changes of working table, but it was found that as the working table was higher, the user felt more comfortable.
        4,000원
        252.
        2012.10 구독 인증기관·개인회원 무료
        We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC50 values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, asignificant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.
        253.
        2012.06 구독 인증기관·개인회원 무료
        Recent advances in stem cell biology have shown that terminally differentiated somatic cells can be directly converted to the different types of somatic cells such as neurons and cardiomyocytes with defined sets of transcription factors without going through a pluripotent state. Recently, it was demonstrated that the hepatocyte-specific transcription factors, Hnf4α plus Foxa1, Foxa2 or Foxa3 could erase somatic memory and reset hepatocyte program on the differentiated somatic genome. Here, we show that Foxa3 together with Hnf4α could efficiently reprogram fibroblasts into hepatocytes. However, the direct conversion into hepatocytes is not observed with Hnf4α plus Foxa1. After two weeks of retroviral transduction of Hnf4α and Foxa3, we observed epithelial colonies emerged from starting fibroblasts and were able to establish stable hepatocyte cell lines, namely induced hepatocytes (iHep cells). The iHep cells closely resemble primary hepatocytes in a number of characteristics such as their polygonal shapes, the hepatic gene expression patterns and the presence of E-cadherin signals as determined by immunocytochemistry. In addition, iHep cells show the storage of glycogen as revealed by Periodic acid-Schiff (PAS) staining, indicating that iHep cells are functionally similar to their in vivo counterparts. Taken together, our findings suggest that the combination of hepatic transcription factors, Hnf4α with Foxa3 but not Foxa1 could induce hepatocyte fate on the differentiated somatic cells.
        254.
        2012.05 구독 인증기관·개인회원 무료
        Rhabditis blumi, isolated from Exomala orientalis, is a necromenic type of nematode that possesses several attributes of a potential biological control agent such as ease in culture conditions, high rates of reproduction and virulence, short life cycle and rapid multiplication etc. Pathogenicity of R. blumi was tested against 5 coleopteran species and 5 lepidopteran species. All insect larvae were susceptible to R. blumi, showing over 60% mortality except for Holotrichia kiotoensis and Ectinohoplia rufipes. The highest mortality was observed in Plutella xylostella (88%), followed by Artogeia rapae, Exomala orientalis, Spodoptera litura and Anomala rufocuprea (over 70%). Reproductive capacity of R. blumi differed from each insect species, ranging from 17 to 656 dauer juveniles/mg of insect larva. Dauer juvenile production was most in Plutella xylostella larvae, producing 656 dauer juveniles/mg of host body weight, followed by E. orientalis, H. kiotoensis, and A. rapae larvae (over 100 dauer juvenile per mg).
        255.
        2012.05 구독 인증기관·개인회원 무료
        The Diadegma fenestrale was known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. This species, genus Diadegma are first reported from Korea. DfIV showed typical ichnovirus shape which two membranes surround virus capsids. The genome contents of DfIV consist about sixteen double-stranded DNA segments ranging 2 to 6 kb. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total viral DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical polydna virus gene family detected such as cys-motif, rep, vinnexin and vankyrin. This is the first report of DfIV and these lepidopteran host immune suppression genes will be deeply identified.
        256.
        2012.03 구독 인증기관 무료, 개인회원 유료
        A 40-year-old male was admitted with dry cough of two months’ duration. Radiologic examination revealed an endobronchial mass obstructing the right middle lobar bronchus and poststenotic pneumonia. Despite failure in bronchoscopic diagnosis, due to suspected malignancy and difficulty for bronchoscopic resection, we performed a right middle lobectomy. The histopathological diagnosis was a lipomatous hamartoma, which was exophytic and endobronchial. We report on a rare surgical case of endobronchial lipomatous hamartoma which had occlusive and exophytic growth across the bronchial wall.
        3,000원
        258.
        2011.10 구독 인증기관·개인회원 무료
        Six plant essential oils, vanillin, and their mixtures were tested for repellent activities against a dengue virus vector mosquito, Aedes aegypti. Their repellency was verified with two conditions: different doses and an addition of vanillin. Among the plant essential oils, lemongrass, lemoneucalyptus and xanthoxylum oils were selected as the potential oils for tertiary mixtures. In bioassays using tertiary mixtures with two essential oils with vanillin, the composition of 1:3:1 (v/v/w) consisted of lemongrass oil, xanthoxylum oil and vanillin provided 270 min-CPT. As a practical application into spatial repellent, the mixture of 1:1:1 formulation containing lemongrass oil, xanthoxylum oil, and vanillin (v/v/w) was enclosed into the Viscopearl, porous cellulose beads that provide gradual release of volatile compounds. We composed this Viscopearl into a module and installed into the air conditioner. Apparently, repellent activity was shown that average repellency of 83.5% was observed for an hour through the chamber test. We confirmed via GC-chromatogram that linalool, geraniol, citral and vanillin were the main compounds of our oil mixture. Our study indicates that personal repellents were possibility applicable to spatial repellents.
        260.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a list of Korean fungivorous Tenebrionidae associated with higher fungi (Basidiomycetes). Most fungivorous tenebrionids are associated with the order Aphyllophorales. A total of31 Tenebrionid species (both adults and larvae) belonging to four tribes (Bolitophagini, Toxicini, Scaphidernini, and Diaperini) are presented in our checklist. Of these, 62 percent are obligate mycetobionts, In addition, 42 fungal hosts of fungivorous tenebrionids are presented. Both thetenebrionids and the fungal hosts reported here are found throughout Korea.
        4,000원