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排序方式: 共有220条查询结果,搜索用时 15 毫秒
11.
Je-Hyuk Lee Tae Ho Kang Byung Hun Um Eun-Hwa Sohn Woo-Cheul Han Seol-Hee Ji Ki-Hyo Jang 《Food science and biotechnology》2013,22(4):1039-1046
To evaluate the possibility for development of apple wine containing medicinal herbs, we have prepared ‘Fuji’ apple (Malus domestica) wines containing pine (Pinus densiflora Siebold et Zuccarini) needle and hwanggi (Radix Astragali)/mistletoe (Viscum album). Normal apple wine was fermented rapidly, but after 40 days fermentation/maturation, the final ethanol content, pH, total acidity, and contents of sugar/organic acid showed similar levels in 3 kinds of apple wines. In other hands, the total phenols content, antocyanins content, and brightness were higher in apple-pine wine and apple-herb wine than in normal apple wine. Apple-herb wine had higher values in total phenol contents, brightness, free amino acid contents, and quenching activity for ABTS free radicals than normal apple wine, and had similar sensory evaluation values with normal apple wine. Taken together, it is supposed that hwanggi and mistletoe might provide functional components to normal apple wine and might be applied to development of functional apple wines. 相似文献
12.
Crude extract and solvent-partitioned fraction of Glehnia littoralis were found to possess different anti-proliferative effects against AGS, HT1080 and U937 human cancer cells. The crude extracts and solvent fractions dose-dependently inhibited cell proliferation. Especially, n-hexane and 85% aqueous MeOH fractions exhibited comparatively higher anti-proliferative effects and reduced expressions of Bcl-2, COX-2 and iNOS genes. Systematic separation of all solvent fractions by chromatographic methods led to the isolation of three glucopyranosides, four furanocoumarins and two polyacetylenic alcohols. All the nine compounds were evaluated for their inhibitory effects against both proliferation of human cancer cells and expressions of MMP-2 and -9 in HT1080 cells. Two polyacetylenic alcohols exerted the highest inhibitory activity against both human cancer cell lines, and MMP-2 and -9. These results suggest that G. littoralis may possibly be used as a valuable chemopreventive agent or food supplement for reducing cancer risk. 相似文献
13.
Drug‐loaded microparticles prepared by the one‐step deposition of calcium carbonate/alginate onto cotton fabrics 下载免费PDF全文
Huan‐Ling Wu Xiao‐Xiao Hou Christopher Branford‐White Xiao‐Zhu Sun Lei Tao Syeda Um‐I‐Zahra Li‐Min Zhu 《应用聚合物科学杂志》2015,132(40)
Calcium carbonate (CaCO3)/alginate inorganic–organic hybrid particles were synthesized and deposited on to the surface of cotton fabrics with a novel one‐step procedure. The effects of the Ca2+/CO32?/alginate molar ratio on the cotton matrix were investigated. The optimization of the process resulted in a regular shaped hybrid microparticles, and scanning electron microscopy revealed that the particles were uniformly distributed on the surface of the fibers. Dynamic light scattering showed that the particles were about 2 μm in diameter. Moreover, transmission electron microscopy images demonstrated that the core–shell structure of the particles existed along with CaCO3 evenly enfolded into the alginate layer. An X‐ray diffraction pattern displayed that the alginate/CaCO3 hybrid microparticles were a mixture of calcite and vaterite crystal. Fourier transform infrared spectroscopy indicated that CaCO3/alginate hybrid particles formed in situ were the only deposited materials. The thermogravimetric analysis curve indicated a certain mass ratio of the alginate and CaCO3 in the hybrid particles. Furthermore, the drug‐loading and drug‐release properties of the hybrid microspheres were studied, and the results show that the water‐soluble diclofenac sodium could be effectively loaded in the hybrid microparticles and the drug release could be effectively sustained. Finally, both of the microparticles and modified fabrics had good cytocompatibility. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42618. 相似文献
14.
Combustion stability limits and NOx emissions of nonpremixed ammonia-substituted hydrogen–air flames
The combustion stability (extinction) limits and nitrogen oxide (NOx) emissions of nonpremixed ammonia (NH3)–hydrogen (H2)–air flames at normal temperature and pressure are studied to evaluate the potential of partial NH3 substitution for improving the safety of H2 use and to provide a database for the nonpremixed NH3-substituted H2–air flames. Considering coflow nonpremixed NH3–H2–air flames for a wide range of fuel and coflow air injection velocities (Vfuel and Vcoflow) and the extent of NH3 substitution, the effects of NH3 substitution on the stability limits and NOx emissions of the NH3–H2–air flames are experimentally determined, while the nonpremixed NH3–H2–air flame structure is computationally predicted using a detailed reaction mechanism. Results show significant reduction in the stability limits and unremarkable increase in the NOx emission index for enhanced NH3 substitution, supporting the potential of NH3 as an effective, carbon-free additive in nonpremixed H2–air flames. With increasing Vcoflow the NOx emission index decreases, while with increasing Vfuel it decreases and then increases due to the recirculation of burned gas and the reduced radiant heat losses, respectively. Given Vcoflow/Vfuel the flame length increases with enhanced NH3 substitution since more air is needed for reaction stoichiometry. The predicted flame structure shows that NH3 is consumed more upstream than H2 due to the difference between their diffusivities in air. 相似文献
15.
Igor N. Adamenko Konstantin E. Nemchenko Alexander V. Zhukov Chung-In Um Thomas F. George Lakshmi N. Pandey 《Journal of Low Temperature Physics》1998,111(1-2):145-179
Starting from the system of linearized kinetic equations, the exact expressions for the spin and mass diffusion coefficients and thermal diffusion ratio in quantum mixtures of helium isotopes with any degree of degeneration is obtained. From the general expression the various limiting expressions have been obtained, which are determined by various relations between collision rates of quasiparticles. The results of the calculations are compared with available experimental data. It is shown that in the low-temperature region, where an impuriton gas is one-component, the relaxation of concentration of
3
He in superfluid
3
He–
4
He mixtures is determined by the acoustic and dissipative collective modes with an effective diffusion coefficient. From the general relation, the expression for a spin diffusion coefficient in solid
3
He–
4
He quantum mixtures is derived. The comparison of the results obtained with the experimental data makes it possible to find a numerical value for the width of the impuriton energy zone. 相似文献
16.
17.
Surface complexation modeling of U(VI) sorption to Hanford sediment with varying geochemical conditions 总被引:1,自引:0,他引:1
A series of U(VI) sorption experiments with varying pH, ionic strength, concentrations of dissolved U(VI), and alkalinity was conducted to provide a more realistic database for U(VI) sorption onto near-field vadose zone sediments at the proposed Integrated Disposal Facility (IDF) on the Hanford Site, Washington. The distribution coefficient (Kd) for U(VI) in a leachate that is predicted to result from the weathering of vitrified wastes disposed in the IDF is 0 mL/g due to the high sodium and carbonate concentrations and high pH of the glass leachate. However, when the pH and alkalinity of the IDF sediment native pore water increases during mixing with the glass leachate, U(VI) uptake is observed and the value of the U(VI) Kd increases 4.3 mL/g, because of U(VI) coprecipitation with newly formed calcite. A nonelectrostatic, generalized composite approach for surface complexation modeling was applied and a combination of two U(VI) surface species, monodentate (SOUO2+), and bidentate (SO2UO2(CO3)2-), simulated the measured U(VI) sorption data very well. The generalized composite surface complexation model, when compared to the constant or single-valued Kd model, more accurately predicted U(VI) sorption under the varying geochemical conditions expected at the IDF. 相似文献
18.
Bioinspired Interlocked and Hierarchical Design of ZnO Nanowire Arrays for Static and Dynamic Pressure‐Sensitive Electronic Skins 下载免费PDF全文
Minjeong Ha Seongdong Lim Jonghwa Park Doo‐Seung Um Youngoh Lee Hyunhyub Ko 《Advanced functional materials》2015,25(19):2841-2849
The development of electronic skin (e‐skin) is of great importance in human‐like robotics, healthcare, wearable electronics, and medical applications. In this paper, a bioinspired e‐skin design of hierarchical micro‐ and nano‐structured ZnO nanowire (NW) arrays in an interlocked geometry is suggested for the sensitive detection of both static and dynamic tactile stimuli through piezoresistive and piezoelectric transduction modes, respectively. The interlocked hierarchical structures enable a stress‐sensitive variation in the contact area between the interlocked ZnO NWs and also the efficient bending of ZnO NWs, which allow the sensitive detection of both static and dynamic tactile stimuli. The flexible e‐skin in a piezoresistive mode shows a high pressure sensitivity (?6.8 kPa?1) and an ultrafast response time (<5 ms), which enables the detection of minute static pressure (0.6 Pa), vibration level (0.1 m s?2), and sound pressure (≈57 dB). The flexible e‐skin in a piezoelectric mode is also demonstrated to be able to detect fast dynamic stimuli such as high frequency vibrations (≈250 Hz). The flexible e‐skins with both piezoresistive and piezoelectric sensing capabilities may find applications requiring both static and dynamic tactile perceptions such as robotic hands for dexterous manipulations and various healthcare monitoring devices. 相似文献
19.
Chung-In Um Jae-Rok Kahng Thomas F. George 《Journal of Low Temperature Physics》1998,112(5-6):399-417
Using a variational Jastrow wavefunction extended to include a three-body correlation function and a hypernetted chain (HNC) and Fermi hypernetted chain (FHNC) scheme with contribution from elementary diagrams, we analyze ground-state energies and structural properties of two-dimensional
3
He-
4
He mixtures. The mixtures are in equilibrium at lower density compared to a pure
4
He system because of the large zero-point energy and statistical correlations due to the fermionic nature of
3
He. We evaluate the lowering of ground-state energies as a function of the impurity concentration and total density of mixtures. Comparing the results with boson
3
He-
4
He mixtures, we evaluate the energy shifts coming from the statistics and analyze the enthalpy to study the miscibility and mobility of each component of the mixture. 相似文献
20.
Low concentrations of ADP are shown to increase the rate of phosphoenzyme formation of E. coli succinyl-coenzyme A (CoA) synthetase (SCS) without altering the fraction of phosphorylated enzyme. This is true when either ATP or succinyl-CoA and Pi are used to phosphorylate the enzyme. The stimulatory effect of ADP is not altered by sample dilution, is retained upon partial purification of the enzyme, and reflects the binding of ADP to a site other than the catalytic site. GDP also alters the phosphorylation of the E. coli SCS but does so primarily by enhancing the level of the phosphoenzyme and only when ATP is used as the phosphate donor. GDP appears to function by neutralizing the action of a specific inhibitory protein. This inhibitor of SCS allows for interconversion of succinate and succinyl-CoA in a manner dissociated from changes in ATP-ADP metabolism. These previously unidentified and varied mechanisms by which SCS is regulated focus attention on this enzyme as an important control point in determining the cell's potential to meet its metabolic demands. 相似文献