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      • SCIESCOPUSKCI등재

        Effects of Dietary Supplementation with Hainanmycin on Protein Degradation and Populations of Ammonia-producing Bacteria In vitro

        Wang, Z.B.,Xin, H.S.,Wang, M.J.,Li, Z.Y.,Qu, Y.L.,Miao, S.J.,Zhang, Y.G. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.5

        An in vitro fermentation was conducted to determine the effects of hainanmycin on protein degradation and populations of ammonia-producing bacteria. The substrates (DM basis) for in vitro fermentation consisted of alfalfa hay (31.7%), Chinese wild rye grass hay (28.3%), ground corn grain (24.5%), soybean meal (15.5%) with a forage: concentrate of 60:40. Treatments were the control (no additive) and hainanmycin supplemented at 0.1 (H0.1), 1 (H1), 10 (H10), and 100 mg/kg (H100) of the substrates. After 24 h of fermentation, the highest addition level of hainanmycin decreased total VFA concentration and increased the final pH. The high addition level of hainanmycin (H1, H10, and H100) reduced (p<0.05) branched-chain VFA concentration, the molar proportion of acetate and butyrate, and ratio of acetate to propionate; and increased the molar proportion of propionate, except that for H1 the in molar proportion of acetate and isobutyrate was not changed (p>0.05). After 24 h of fermentation, H10 and H100 increased (p<0.05) concentrations of peptide nitrogen and AA nitrogen and proteinase activity, and decreased (p<0.05) $NH_3$-N concentration and deaminase activity compared with control. Peptidase activitives were not affected by hainanmycin. Hainanmycin supplementation only inhibited the growth of Butyrivibrio fibrisolvens, which is one of the species of low deaminative activity. Hainanmycin supplementation also decreased (p<0.05) relative population sizes of hyper-ammonia-producing species, except for H0.1 on Clostridium aminophilum. It was concluded that dietary supplementation with hainanmycin could improve ruminal fermentation and modify protein degradation by changing population size of ammonia-producing bacteria in vitro; and the addition level of 10 mg/kg appeared to achieve the best results.

      • SCIESCOPUSKCI등재

        Effects of Addition Level and Chemical Type of Propionate Precursors in Dicarboxylic Acid Pathway on Fermentation Characteristics and Methane Production by Rumen Microbes In vitro

        Li, X.Z.,Yan, C.G.,Choi, S.H.,Long, R.J.,Jin, G.L.,Song, Man K. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.1

        Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

      • KCI등재

        Low temperature synthesis of nano-crystalline h-boron nitride from boric acid/ urea precursors

        Dina H.A. Besisa,Mahmoud A. A. Hagras,Emad M.M. Ewais,Yasser M. Z. Ahmed,Zaki I. Zaki,Adel Ahmed 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

        Nano-crystalline hexagonal-boron nitride (h-BN) have promised a broad range of interesting applications due to its uniquecharacteristics. In this work, nano-structured h-BN has synthesized by a low temperature-one step reaction of completelydissolved solution of commercial and low cost boric acid and urea fertilizer. Effect of different concentrations of urea, reactionatmosphere (air-N2) and firing temperature (600, 800 oC) on the production of h-BN and type of yield were investigated. Theformation of hexagonal boron nitride was proved from the binding energy for boron and nitrogen obtained from the X- rayphotoelectron spectrum (XPS). The structural phase of the product was confirmed by X-ray diffraction (XRD), Fourier transforminfrared (FT-IR) and differential thermal analysis (DTA). Transmission electron microscopy (HRTEM) has revealed the nanostructure nature of the synthesized boron nitride. The results indicated that, nano-crystalline h-BN with a crystallite size of ≈ 4.5nm has formed at low temperature of 800 oC. Moreover, a good thermal stability and oxidation resistance of h-BN can besynthesized with low cost and at low temperature in the nanoscale and has high potential to be used in advanced applications.

      • KCI등재

        Microstructural Stability and Creep Performance of a Novel Low-Cost Single Crystal Superalloy

        Z. H. Tan,X. G. Wang,Y. L. Du,Y. M. Li,Y. H. Yang,J. L. Liu,J. D. Liu,J. G. Li,Y. Z. Zhou,X. F. Sun 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

        The increasing pursuit of advanced aero-engines with lower ratio between the cost and performance has greatly promotedthe demanding of single crystal superalloys characterized by low cost and outstanding temperature capability. In this study,a novel low-cost single crystal superalloy was designed and the creep tests as well as micro-characterization were carried outon the experimental alloy. The results illustrated that the novel single crystal alloy exhibited an ideal microstructural stabilitywithout precipitating TCP phases, after long-term thermal exposure at the ultimate service temperature of third generationsingle crystal superalloys. Moreover, the experimental alloy with only 3 wt% Re addition demonstrated remarkable creepresistance and maintained a very low minimum creep rate at 1100 °C/137 MPa and 1120 °C/137 MPa, while the accumulationand coalescence of micro-pores had eventually led to the alloy fracture. Apart from that, the compact interfacial dislocationnetworks the 2nd γ′ phase were observed after high-temperature creep rupture, and the typical a < 010 > superdislocationswith relatively poor mobility was found at 1120 °C. At 760 °C/800 MPa, both the minimum creep velocity and entire creepstain was increased evidently, however, the ultimate creep rupture life of the alloy had still reached 200 h. The correspondingdeformation mechanism was identified as the combination of superdislocation pairs shearing and a/3 < 121 > partial dislocationcutting the γ′ phase with a SISF being generated. In general, the novel single crystal alloy characterized by remarkablemechanical properties and cost reduction possesses a great potential for future application in the advanced aircraft engines.

      • KCI등재후보

        麥類의 屬間交雜에 關한 硏究 Ⅰ. 麥種間 相互交雜 및 EACA 處理가 雜種種子 形成에 미치는 影響

        C.H. CHO(曺章煥),W.S. AHN(安完植),M.Z. KIM(金文子),K.S. MIN(閔庚洙) 한국육종학회 1977 한국육종학회지 Vol.9 No.1

        Inter-generic hybridizations were made among the species T. aestivum, T. durum, H. vulgare and S. cereale using 0.1% concentration of immunosuppressant EACA treatment, The results obtained were as follows; 1. In reciprocal T. aestivum x H. vulgare crosses no viable seed were obtained. The cross T. durum x H. vulgar gave 6 viable seeds. 2. The cross H. vulgare x S. cereale resulted in 9.2% of the, fertilized florets setting seed. However, none had a hybird embryo. The reciprocal gave a 0.12% seed set. 22 seeds were viable from the 31 seeds obtained from this cross. 3. T. aestivum x S. cereale cross resulted in 26.3% of the fertilized florets setting seed. In T. durum x S. cereale crosses, 10.6% of the fertilized florets set seed. 4. A differential response to a 0.1% concentration of EACA was observed. T. aestivum intergeneric crosses showed a 4.8% to a 6.0% higher seed set than did none treated plants. However, H. vulgare plants gave a low seed set than did the none treated plants.

      • KCI등재후보

        쌀 胚乳의 Amylose含量에 미치는 Wx 因子의 Dosage 効果 1. Base Color의 Isogenic Line을 利用한 交配種子의 Amylose含量

        M. H. Heu(許文會),S. Z. Park(朴淳直) 한국육종학회 1976 한국육종학회지 Vol.8 No.1

        Isogenic lines for glutinous endosperm and base color in rice were used to obtain different endosperm genotypes, wxwxwx, wxwxWx, WxWxwx and WxWxWx. The base color was used as the marker gene to elliminate the selfed seeds. The amylose content of rice endosperm was significantly different among genotypes. The dosage effect of the Wx allele seemed to be additive in its action on the amylose content, though the amylose content is not directly proportional to the number of Wx dose. The effects of Wx allele to wx and H-Wx allele to L-Wx, the first one dose (xwxw Wx/L, wxwx Wx/H and WxWx/L Wx/H) is most significant and the effect of 2 doses(WxWx wx/L and WxWx wx/H) and 3 doses (WxWxWx/L and WxWxWx/H) were linearly increased.

      • SCIESCOPUS

        Dynamic output-feedback-based H<sub>~</sub> design for networked control systems with multipath packet dropouts

        Tang, Z.,Park, J.H.,Lee, T.H. Elsevier [etc.] 2016 Applied mathematics and computation Vol.275 No.-

        <P>This paper is devoted to the stability of networked control system with time-varying delays. A dynamic output feedback controller is designed to realize H-infinity control of the networked system with the H-infinity performance attenuation level gamma. Since the frequent occurrence of packet dropouts and communication delays which all could degrade the performance of system or even cause system instability, we consider the networked control system with both input and output packet dropouts and bidirectional time-varying communication delays. Some sufficient conditions are obtained to grantee asymptotic stability of the system in view of Schur complement and singular values decomposition of matrix. Afterwards, intensive analysis is carried out to present the existence of admissible dynamic output feedback controller by applying an appropriate weighting method which introduces slack matrices variables. What is more, a numerical example is presented to illustrate the validity of theoretical analysis. (C) 2015 Elsevier Inc. All rights reserved.</P>

      • SCISCIESCOPUS

        Separation dynamics of hydrogen isotope gas in mesoporous and microporous adsorbent beds at 77 K: SBA-15 and zeolites 5A, Y, 10X

        Chu, X.Z.,Cheng, Z.P.,Xiang, X.X.,Xu, J.M.,Zhao, Y.J.,Zhang, W.G.,Lv, J.S.,Zhou, Y.P.,Zhou, L.,Moon, D.K.,Lee, C.H. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.9

        The separation of a hydrogen isotope mixture on porous materials was studied using equilibrium and breakthrough experiments. The adsorption equilibria of H<SUB>2</SUB> and D<SUB>2</SUB> on SBA-15 with mesopores and molecular sieves 5A, Y, and 10X with micropores were measured at 77 K using the volumetric method. The breakthrough experiments of a H<SUB>2</SUB> and D<SUB>2</SUB> mixture in each adsorbent bed were carried out at various conditions of flow rate and pressure. The equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> on mesoporous molecular sieves was larger than the ratio on microporous molecular sieves (SBA-15 > 10X > Y > 5A), but the difference among the adsorbents decreased with increases in pressure. On the other hand, the order of breakthrough separation factor showed the opposite result (SBA-15 < 10X < Y < 5A). The breakthrough separation factors for zeolite 10X was approximately equal to the equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> at the corresponding partial pressures, whereas zeolites 5A and Y showed higher breakthrough separation factors than their equilibrium ratios. In SBA-15, the separation factors from breakthrough results were even smaller than the corresponding equilibrium ratio. In the microporous adsorbent with a limited pore size (zeolite 5A in the study), the diffusion mechanism contributed to the separation of hydrogen isotope gases as one of key factors.

      • SCISCIESCOPUS

        A superoxide anion generator, pyrogallol induces apoptosis in As4.1 cells through the depletion of intracellular GSH content

        Park, W.H.,Han, Y.W.,Kim, S.H.,Kim, S.Z. Elsevier 2007 Mutation research Vol.619 No.1-2

        We investigated the involvement of ROS such as H<SUB>2</SUB>O<SUB>2</SUB> and O<SUB>2</SUB>?<SUP>-</SUP>, and GSH in As4.1 cell death induced by pyrogallol. The intracellular H<SUB>2</SUB>O<SUB>2</SUB> levels were decreased or increased depending on the concentration and incubation time of pyrogallol. The levels of O<SUB>2</SUB>?<SUP>-</SUP> were significantly increased. Pyrogallol reduced the intracellular GSH content. And ROS scavengers, Tempol, Tiron, Trimetazidine and NAC could not significantly down-regulate the production of H<SUB>2</SUB>O<SUB>2</SUB> and O<SUB>2</SUB>?<SUP>-</SUP>. However, these ROS scavengers slightly inhibited apoptosis. Interestingly, Tempol showing the recovery of GSH depletion induced by pyrogallol significantly decreased apoptosis without the significant reduction of intracellular O<SUB>2</SUB>?<SUP>-</SUP> levels. SOD and catalase did not change the level of H<SUB>2</SUB>O<SUB>2</SUB> but decreased the level of O<SUB>2</SUB>?<SUP>-</SUP>. The inhibition of GSH depletion by these was accompanied with the decrease of apoptosis, as evidenced by sub-G1 DNA content, annexin V staining, mitochondria membrane potential (ΔΨ<SUB>m</SUB>) and Western data. In addition, ROS scavengers and SOD did not alter a G2 phase accumulation of the cell cycle induced by pyrogallol. However, catalase changed the cell cycle distributions of pyrogallol-treated cells to those of pyrogallol-untreated cells. In summary, we have demonstrated that pyrogallol potently generates ROS, especially O<SUB>2</SUB>?<SUP>-</SUP>, in As4.1 JG cells, and Tempol, SOD and catalase could rescue to a lesser or greater extent cells from pyrogallol-induced apoptosis through the up-regulation of intracellular GSH content.

      • Phytochemical Analysis and Anti-cancer Investigation of Boswellia Serrata Bioactive Constituents In Vitro

        Ahmed, Hanaa H,Abd-Rabou, Ahmed A,Hassan, Amal Z,Kotob, Soheir E Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

        Cancer is a major health obstacle around the world, with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as major causes of morbidity and mortality. Nowadays, there isgrowing interest in the therapeutic use of natural products for HCC and CRC, owing to the anticancer activity of their bioactive constituents. Boswellia serrata oleo gum resin has long been used in Ayurvedic and traditional Chinese medicine to alleviate a variety of health problems such as inflammatory and arthritic diseases. The current study aimed to identify and explore the in vitro anticancer effect of B. Serrata bioactive constituents on HepG2 and HCT 116 cell lines. Phytochemical analysis of volatile oils of B. Serrata oleo gum resin was carried out using gas chromatography-mass spectrometry (GC/MS). Oleo-gum-resin of B. Serrata was then successively extracted with petroleum ether (extract 1) and methanol (extract 2). Gas-liquid chromatography (GLC) analysis of the lipoidal matter was also performed. In addition, a methanol extract of B. Serrata oleo gum resin was phytochemically studied using column chromatography (CC) and thin layer chromatography (TLC) to obtain four fractions (I, II, III and IV). Sephadex columns were used to isolate ${\beta}$-boswellic acid and identification of the pure compound was done using UV, mass spectra, $^1H$ NMR and $^{13}C$ NMR analysis. Total extracts, fractions and volatile oils of B. Serrata oleo-gum resin were subsequently applied to HCC cells (HepG2 cell line) and CRC cells (HCT 116 cell line) to assess their cytotoxic effects. GLC analysis of the lipoidal matter resulted in identification of tricosane (75.32%) as a major compound with the presence of cholesterol, stigmasterol and ${\beta}$-sitosterol. Twenty two fatty acids were identified of which saturated fatty acids represented 25.6% and unsaturated fatty acids 74.4% of the total saponifiable fraction. GC/MS analysis of three chromatographic fractions (I,II and III) of B. Serrata oleo gum resin revealed the presence of pent-2-ene-1,4-dione, 2-methyl- levulinic acid methyl ester, 3,5- dimethyl- 1-hexane, methyl-1-methylpentadecanoate, 1,1- dimethoxy cyclohexane, 1-methoxy-4-(1-propenyl)benzene and 17a-hydroxy-17a-cyano, preg-4-en-3-one. GC/MS analysis of volatile oils of B. Serrata oleo gum resin revealed the presence of sabinene (19.11%), terpinen-4-ol (14.64%) and terpinyl acetate (13.01%) as major constituents. The anti-cancer effect of two extracts (1 and 2) and four fractions (I, II, III and IV) as well as volatile oils of B. Serrata oleo gum resin on HepG2 and HCT 116 cell lines was investigated using SRB assay. Regarding HepG2 cell line, extracts 1 and 2 elicited the most pronounced cytotoxic activity with $IC_{50}$ values equal 1.58 and $5.82{\mu}g/mL$ at 48 h, respectively which were comparable to doxorubicin with an $IC_{50}$ equal $4.68{\mu}g/mL$ at 48 h. With respect to HCT 116 cells, extracts 1 and 2 exhibited the most obvious cytotoxic effect; with $IC_{50}$ values equal 0.12 and $6.59{\mu}g/mL$ at 48 h, respectively which were comparable to 5-fluorouracil with an $IC_{50}$ equal $3.43{\mu}g/mL$ at 48 h. In conclusion, total extracts, fractions and volatile oils of B. Serrata oleo gum resin proved their usefulness as cytotoxic mediators against HepG2 and HCT 116 cell lines with different potentiality (extracts > fractions > volatile oil). In the two studied cell lines the cytotoxic acivity of each of extract 1 and 2 was comparable to doxorubicin and 5-fluorouracil, respectively. Extensive in vivo research is warranted to explore the precise molecular mechanisms of these bioactive natural products in cytotoxicity against HCC and CRC cells.

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