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        검색결과 36

        1.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to extend the business viability of carbon nanotubes (CNTs), research on CNT dispersion in a solvent as well as in polymer matrix should be established. Herein, three kinds of dispersing agents, sodium deoxycholate (DOC), sodium dodecylbenzene sulfonate (NaDDBS), polyvinyl pyrrolidone (PVP), are selected and applied to quantify the dispersibility and dispersion stability of CNT aqueous dispersion. The dispersibility of CNT dispersion with the PVP, evaluated via viscosity and particle size analyses, are superior to those with the DOC and NaDDBS dispersing agents. CNT aqueous solution dispersed with PVP showed slightly higher viscosity and narrower particle size distribution than those with DOC and NaDDBS dispersing agents. In addition, the dispersion stability of CNT dispersion with the PVP, measured via lumisizer analyses, are superior to those with the DOC and NaDDBS dispersing agents. HR-TEM analysis verifies that the outstanding dispersibility and dispersion stability of CNTs in aqueous solution are due to the effect of the robust polymer wrapping of the PVP dispersing agent on the CNT surface. From the results of this study, the guidelines for the selection of the suitable dispersing agents and the systematic evaluation of dispersibility and dispersion stability of CNT dispersions can be suggested.
        4,200원
        2.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The carbon anode material for lithium-ion battery was prepared by pyrolysis fuel oil and waste polyethylene terephthalate (PET) additive. The pitch was synthesized as a medium material for carbon anode by heat treatment. The waste PET additive improved the softening point and thermal stability of the pitch. La and Lc of the anode material (heat-treated pitch) increased at higher treatment temperature but decreased by waste PET additive. The electric capacity was evaluated based on effects of defective cavity and developed graphite interlayer, respectively. When the La and Lc of the anode material decreased, the electric capacity by cavity increased based on defective graphite structure. Therefore, the addition of waste PET causes the improved capacity by the cavity. The anode material which has a high efficiency (over 95%) and C-rate (95%, 2 C/0.1 C) was obtained by controlling the process of heat treatment and PET addition. The mechanism of lithium-ion insertion was discussed based on effects of defective cavity and developed graphite interlayer.
        4,000원
        3.
        2017.11 구독 인증기관·개인회원 무료
        In a previous study, it was reported that enzymatic hydrolysis under pressurization could be a new method which could produce arginine dipeptide and free amino acid in anchovy hydrolysate as salty enhancer at optimal condition. Powder is more efficient than liquid in terms of transport and storage stability. For the purpose of producing spray dried powder of various salt contents was investigated the effect of different salt concentration of anchovy hydrolysate on spray dried powder properties. The anchovy hydrolysate of various salt contents(in the range of approximately 0.7- 19.8% w/w) prepared adding the fish sauce (Dae-Young fish market) at inlet drying air temperatures of 120°C and 140°C. The process yield and physicochemical properties such as moisture content, bulk density, hygroscopicity and the morphology (EDS, XPS, XRD) of the anchovy hydrolysate powder was measured. The glass transition temperatures (Tg) of the powders equilibrated under various water activities were determined using a differential scanning calorimeter (DSC). Different drying conditions and salt concentration could generate anchovy hydrolysate powders with different process yield, bulk density and moisture content. The spray-dried anchovy hydrolysate powder was confirmed by XRD to be a mixture of an amorphous substances and crystalline salts. The energy dispersive X-ray spectrometer (EDS) and X-Ray Photoelectron Spectroscopy (XPS) analysis demonstrated that the surface NaCl concentration of the powders increased with an increasing drying air temperature. Increasing moisture adsorption of the anchovy hydrolysate powders resulted in a Tg reduction. It is suggested that producing spray dried anchovy hydrolysate for the industrial use is the use of the feed salt concentration of not lower than % w/w and inlet air temperature at 120°C, 140°C
        5.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of nanostructured functional materials derived from biomass and/or waste is of growing importance for creating sustainable energy-storage systems. In this study, nanoporous carbonaceous materials containing numerous heteroatoms were fabricated from waste coffee grounds using a top-down process via simple heating with KOH. The nanoporous carbon nanosheets exhibited notable material properties such as high specific surface area (1960.1 m2 g–1), numerous redox-active heteroatoms (16.1 at% oxygen, 2.7 at% nitrogen, and 1.6 at% sulfur), and high aspect ratios (>100). These unique properties led to good electrochemical performance as supercapacitor electrodes. A specific capacitance of ~438.5 F g–1 was achieved at a scan rate of 2 mV s–1, and a capacitance of 176 F g–1 was maintained at a fast scan rate of 100 mV s–1. Furthermore, cyclic stability was achieved for over 2000 cycles.
        4,000원
        6.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hippo signaling is one of the signal transduction pathways revealed in Drosophila and mammalian. This signaling is known to control proliferation and growth of normal cells or cancer cells, in which many signaling proteins form a network. In this network, tumor suppressor kinases include MST and LATS while YAP and TAZ exist as oncoproteins. Combined with transcription factor, YAP the oncoprotien starts to secrete growth factors such as CTGF, FGF, and Cry61 regulating the growth of cells or the organ sizes. The YAP is also associated with the development of early embryo and the regeneration of the skin wound as well as abnormal growth of cancers in case of over-expression. Although many previous studies have found various tumors with YAP over-expressed, the expression of YAP is not yet clearly identified in oral cancer. The aim of this study was to check the expression level of YAP in oral squamous cell carcinoma. So we performed PCR and Western blot to check YAP expression in mRNA and protein level respectively. In result, all of the 13 cell lines examined has presented the expression of YAP, and especially in HSC2 and KOSCC11 cell lines has been observed the remarkable level of expression. In conclusion, we confirmed the overexpression of YAP cell line in oral squamous cell carcinoma, it will be a great help to the study carried out in the future. Once you understand the mechanism of oncoprotien YAP in oral cancer cells, it seems possible to research and development of targeted tumor therapy agents in oral cancer.
        4,000원
        7.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oral squamous cell carcinoma (OSCC) is one of the most common carcinomas in the head and neck area. Bitter melon extraction (Momordicacharantia, BME) has been used as a functional food to prevent and treat human health related issues. It has recently been reported that BME inhibits breast cancer cell growth by arresting cell cycle and promoting apoptosis. In this study, we aimed at proving the inhibitory action of BME on OSCC proliferation. We used two OSCC cell lines, SCC4 and Ca9-22. Both cell lines were treated with different concentrations (1%, 2%, and 5%) of BME. Cell viability was examined by MTT assay. DNA condensation was visualized by immunofluorescence microscope to determine the signs of the cell apoptosis. Cell numbers were significantly decreased in a dose-dependent manner by bitter melon at concentration of 1% of BME on Ca9-22 cell line (P=0.001) but no significant effect on SCC4 (P=0.124) at the same concentration. 2% BME treatment of the Ca9-22 cell line induces chromatin condensation and DNA fragmentation after 20 hours. It seems that BME inhibits the proliferation of Ca9-22 cell line by inducing apoptosis. Thus, BME may be used as a dietary supplement for prevention of OSCC.
        4,000원
        9.
        2010.05 구독 인증기관·개인회원 무료
        Apolipophorin-III (apoLp-III) is a hemolymph protein whose function is to facilitate lipid transport in an aqueous medium in insects. Recently, apolipophorin-III in Galleria mellonella and Hyphantria cunea was shown to play an unexpected role in insect immune activation. We show here a novel possible function/role of the apoLp-III in insects. To investigate the genes which have a relationship with apoLp-III in fall webworm larvae, we reduced endogenous Hc apoLp-III mRNA levels in larvae via RNA interference (RNAi). The RNAi-mediated Hc apoLp-III reduction resulted in the reduction of antioxidants, like MnSOD, catalase, and glutathione S transferase as well as immune proteins. In particular, expression of MnSOD commonly decreased in fat body, midgut, and hemocytes following the knockdown of Hc apoLp-III, which induced an elevated level of superoxide anion in Hyphantria cunea larvae. The observed effect of Hc apoLp-III RNAi suggests that Hc apoLp-III is related to the action/expression of antioxidants, especially MnSOD.
        10.
        2009.05 구독 인증기관·개인회원 무료
        Apolipophorin-Ⅲ (apoLp-Ⅲ) is a hemolymph protein whose function is to facilitate lipid transport in an aqueous medium in insect. Recently, apolipophorin-Ⅲ in Galleria mellonella and Hyphantria cunea was shown to play an unexpected role in insect immune activation. We show here a novel possible function/role of apoLp-Ⅲ in insects. To investigate the genes which have a relationship with apoLp-Ⅲ in fall webworm larvae, we reduction of endogenous Hc apoLp-Ⅲ mRNA levels in larvae via RNA interference (RNAi). The RNAi-mediated Hc apoLp-Ⅲ reduction resulted in the reduction of antioxidants, like MnSOD, catalase, and glutathione S transferase as well as immune proteins. In particular, expression of MnSOD commonly decreased in fat body, midgut, and hemocytes following the knockdown of Hc apoLp-Ⅲ, which induced an elevated level of superoxide anion in H. cunea larvae. The observed effect of Hc apoLp-Ⅲ RNAi suggests that Hc apoLp-Ⅲ is related to the action/expression of antioxidants.
        11.
        2009.05 구독 인증기관·개인회원 무료
        Innate immunity responses are triggered by the immune challenge and therefore involve signaling processes. The cellular response is initiated by hemocytes and mainly involves phagocytosis and encapsulation of intruders by these cells. To address whether Hc-STAT is activated upon bacterial challenge, we examined the subcellular location of STAT protein in hemocyte by immunostaining. A new insect member of the STAT family of transcription factors (Hc-STAT) has been cloned from the lepidopteran, Hyphantria cunea. The domain involved in DNA interaction and the SH2 domain are well conserved. The gene is transcribed at a low level during all stages of development, and the protein is present in hemocytes, fat body, midgut, epidermis, and Malphigian tuble (Mt). Especially, hemocytes and Mt showed transcriptional activation of Hc-STAT upon Gram (-) bacteria and fungal challenge. Gram (-) bacteria and fungal challenge specifically results in nuclear translocation of Hc-STAT protein and induction of DNA-binding activity that recognizes a STAT target site in H. cunea hemocyte. In vitro treatment with pervanadate translocates Hc-STAT to the nucleus in hemocyte cells. Here we report the first evidence for the involvement hemocyte JAK/STAT pathway upon microbial infection in lepidopteran insect.
        12.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The techniques of IVM, IVF and IVC of canine oocytes may provide useful information for gamete salvage programs and the conservation of endangered canidae. This investigation has been made to determine the efficiency of in vitro maturation (IVM) as a basic experiment to study the development of canine oocytes after in vitro fertilization (IVF). The rate of oocytes developing to the MII stage was higher in the hormone treated group (10 IU/ml hCG+eCG, 14.7%, p<0.05) than in the control group (0 IU/ml hCG+eCG, 10.0%). The monospermy and pronuclear rates of canine oocytes were investigated after caffeine treatment on IVF. Canine oocytes were fertilized in the Fert‐TALP medium supplemented with 0, 10, 20 or 30 mM caffeine (Fert I, Fert II, Fert III or Fert IV, respectively). The highest pronuclear formation rate was obtained in the Fert I for 24 h IVF (6.7%, 6/89). Therefore, it is believed that unlike in other mammals, caffeine in canine IVF does not increase the efficiency of fertilization rate, and is not an important factor.
        4,000원
        13.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Epithelial-mesenchymal transition(EMT) plays a pivotal role in the convers ion of earl y s tage tumors into invasive malignancies‘ and has been shown to be regulated hy the transcri ptional factor. Snail. Recent ly‘ actlvatlon of the phosphatidylinositol 3' kinase (PI3K)/따<:T axis is emerging as a centra l feature of EMT‘ However. it is unclear whether the phosphorylation of AKT regulate the expl'ession of s nail in ora l cancer cell underwent EMT. T。 investigate a role of p-AKT in EMT, we assessed the effects of inhibi ting p-AK1' activity in oral squamous can cer cells(KOSCC-25B) using PIAs, structurally modified phosphatidyli nositol ether lipid analogues(P1As) . PIAs de creased phosphorylation of c-Jun N-terrninal Kinase(JNK) and increased phosphorylation of glycogen synthase kinase 3beta(GSK-3beta). Inhibition of p-AKT ir빼ce d down regulation of Snail and Twist. but Sip1 regulated independent of p-AKT inhibition. Also inhibi tion of p-AKT dec reased cell migration and invas ion. Therefore our results implicate that p-AKT may contribute to the translocalization of sna il in the EMT associated with canceJ cell rnigration and invasion
        14.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Although a number of molecules have been implicated in the metastasis of oral squamous cell carcinoma (OSCC) , the precise molecular mechanisms that deterrnine the direction of rnigration and invasiveness of OSCC cells into the lymph nodes remain unclear, Chemokines are a superfarnily of small structurally related heparin- binding proteins‘ which have been identified as attractants that control the rnigration of leukocytes‘ especia lly during imrnune and inflammatory reactlOns Moreover, recent studies have demonstrated that several types 。f cancer express chemokine receptor‘s and use chemokines to metastasize to the target organ, However, there h ave been few reports on biological behaviors by downregulation 0 1' CXCR-4 in ora l cancel‘ cells We tried to screen several OSCC cell lines in order to obtain a suitable cell line model which had the cha ract eris tic of the constitutive ly expressed state of CXCR• 4 Of the several OSCC cell lines, only KOSCC-25B showed the high expression of CXCR-4 in both RT-PCR and Western blot analysis, siRNA-CXCR-4 infected subclones of KOSCC-25B(Si, 3‘ Si 1이 showed downregulation of CXCR-4 expression as expected‘ At serum-free co ndi tion‘ Si.3 s ubclone s ignif icantly decreased cell proliferations at 24 h and 48h and Si, lO subclone significant ly dec reased cell proliferations at 24 h Si ,3 clone dec reased to 67 ,4% and Si,lO clone to 65 ,5% in comparison to vector infected cells These data suggest that the downregulation of CXCR-4 expression could induce anti-rnigratory and ant i- rni g ratory effect
        16.
        2002.10 구독 인증기관 무료, 개인회원 유료
        The main objective of this paper to purpose a evaluating methods of process capability measures for exponential distributed quality characteristics. For correctly evaluating process capability , the first thing , exponential data is applied the Lilliefors test statistic to the null hypothesis of nornality. The next , exponential parameters is estimated in terms of MLE , ME , MME and then evaluated , respectively , process capability index based on exponential curved (Cpe). We consider simultaneously process capability messures based on Pearson system, Johnson system and Burr system.
        4,000원
        18.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        "Oraebyeo" is mutation of a high quality japonica cultivar, Ilpumbyeoa new japonica rice(Oriza sativa L.) cultivar developed from by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res. & Ext. Service in 2006. This variety heads 20 days earlier than Ilpumbyeo and similar to that of Odaebyeo an early maturing leading cultivar of northern plain area of Korea. Compared with Odaebyeo has a good semi-erect plant type with lodging tolerance due to much shortened plant hight(l2cm shorter than Odaebyeo). Oraebyeo has similar panicle number with Odaebye where as it has more spikelets per panicle. However, this variety less the ratio of ripened grains and 1,000 grain weight than those of Odaebyeo. The yield performance of this cultivar in milled rice was about 5.09MT/ha in local adaptability test conducted for three years 2002-2004 and 5.51MT/ha in the demonstration plot of farmer's field.
        19.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        Sanggolbyeo is a new japonica rice cultivar developed from Ilpumbyeo mutation lines by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res.& Ext. Service in 2006. This cultivar has about 135 days growth duration from transplanting to harvesting. Sanggolbyeo has short and round grain and non-glutinous endosperm with very low phytate content, below 50% of Ilpumbyeo, implying it could help men to absorb Calcium from rice. This cultivar shows midium diseases tolerance to leaf blast, bacterial blight, virus and insect pest. The milled rice yield of Sanggolbyeo is about 4.98 MT/ha at ordinary transplanting culture in the local adaptability test. Sanggolbyeo would be adaptable for the mid-northern plain areas of Korea.
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