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131.
For the fist time the preparation of a mostly solid-state high efficiem electro-conductive material comprising 1-methyl-3-propylimidazolium iodide (MPII), benzimidazole (BI), iodine and lithium iodide was reported. In this electrolyte, BI acts as not only additives but also gelators. With its significant electrochemical properties, an overall efficiency of 3.07% was achieved under AM 1.5 (100 mW/cm^2). 相似文献
132.
Cilia of hair cells are structurally similar to unilaminar phospholipid vesicles. The close juxtaposition of adjacent cilia is similar to the intervesicle distances found in groups of vesicles. Both cilia and vesicles operate in similar ionic environments. By comparing the cross section of cilia, which are cylinders with the cross section of vesicles, which are spherical, we can see how colloid theory can be applied to both cilia and vesicles. While vesicles have been studied as colloid particles, thus far colloid theory has not been applied to hair cell cilia. This paper presents a basic explanation of colloid theory in a simple graphic form that facilitates a colloid perspective of hair cell cilia behavior. A review of relevant hair cell cilia behavior supports the hypothesis that colloid knowledge is applicable to the problem of understanding cilia functionality in the hair cell. The electromagnetic nature of colloid forces allows for their involvement in the relatively high speed operation required of hair cells which are dealing with signals of up to 2×105 Hz. A fresh look at the biophysics of the hair cell from a colloid perspective may lower the barrier to a closer understanding of active mechanical sensory transduction, amplification and adaptation, and suggest a new domain for the application of colloid theory. 相似文献
133.
Natural products of the medicinal fungus Ganoderma lucidum: occurrence,biological activities,and pharmacological functions 总被引:1,自引:0,他引:1
Shiao MS 《Chemical record (New York, N.Y.)》2003,3(3):172-180
Ganoderma lucidum, a fungus used in traditional Chinese medicine, produces polysaccharides and oxygenated triterpenoids with a very broad spectrum of biological activities and pharmacological functions. Among the Ganoderma triterpenoids, many pairs of C-3 alpha/beta stereoisomers and C-3/C-15 positional isomers have been identified. Biosynthetic study has indicated that the C-3alpha series of oxygenated triterpenoids is derived from the C-3beta series via an oxidation-reduction pathway. The interaction of Ganoderma triterpenoids with human platelets in the induction of aggregation and inhibition of agonist-induced aggregation and signal transduction has been elucidated. Reduction of cellular mevalonate content to a stage in which cholesterol synthesis is strongly inhibited and cell growth is marginally arrested sensitizes hepatoma cells to the oxygenated triterpenoids. A combination treatment of lovastatin and Ganoderma triterpenoids in animal studies has exhibited a potential anticancer effect. 相似文献
134.
Hayley A. Every Michael A. Hickner James E. McGrath Thomas A. Zawodzinski Jr. 《Journal of membrane science》2005,250(1-2):183-188
Methanol diffusion in two polymer electrolyte membranes, Nafion 117 and BPSH 40 (a 40% disulfonated wholly aromatic polyarylene ether sulfone), was measured using a modified pulsed field gradient NMR method. This method allowed for the diffusion coefficient of methanol within the membrane to be determined while immersed in a methanol solution of known concentration. A second set of gradient pulses suppressed the signal from the solvent in solution, thus allowing the methanol within the membrane to be monitored unambiguously. Over a methanol concentration range of 0.5–8 M, methanol diffusion coefficients in Nafion 117 were found to increase from 2.9 × 10−6 to 4.0 × 10−6 cm2 s−1. For BPSH 40, the diffusion coefficient dropped significantly over the same concentration range, from 7.7 × 10−6 to 2.5 × 10−6cm2 s−1. The difference in diffusion behavior is largely related to the amount of solvent sorbed by the membranes. Increasing the methanol concentration results in an increase in solvent uptake for Nafion 117, while BPSH 40 actually excludes the solvent at higher concentrations. In contrast, diffusion of methanol measured via permeability measurements (assuming a partition coefficient of 1) was lower (1.3 × 10−6 and 6.4 × 10−7 cm2 s−1 for Nafion 117 and BPSH 40 respectively) and showed no concentration dependence. The differences observed between the two techniques are related to the length scale over which diffusion is monitored and the partition coefficient, or solubility, of methanol in the membranes as a function of concentration. For the permeability measurements, this length is equal to the thickness of the membrane (178 and 132 μm for Nafion 117 and BPSH 40 respectively) whereas the NMR method observes diffusion over a length of approximately 4–8 μm. Regardless of the measurement technique, BPSH 40 is a greater barrier to methanol permeability at high methanol concentrations. 相似文献
135.
Summary A packed flow cell was used for fluorometric detection in micro high-performance liquid chromatography. The flow cell consisted of fused-silica tubing packed with the same material as the separation column. A focusing effect of the stationary phase on the signal intensity was observed, leading to an improvement of the mass detection limit, as achieved by on-column detection. 相似文献
136.
Benzathine is prepared in good yields from cyanobenzene by a combination of electrochemical hydrogenation and Kolbe electrolysis using nickel and platinum electrodes in the presence of methanolic sodium methoxide in an undivided cell. 相似文献
137.
Nasib Qureshi Patrick Karcher Michael Cotta Hans P. Blaschek 《Applied biochemistry and biotechnology》2004,114(1-3):713-721
Corn steep liquor (CSL), a byproduct of the corn wet-milling process, was used in an immobilized cell continuous biofilm reactor
to replace the expensive P2 medium ingredients. The use of CSL resulted in the production of 6.29 g/L of total acetone-butanol-ethanol
(ABE) as compared with 6.86 g/L in a control experiment. These studies were performed at a dilution rate of 0.32 h−1. The productivities in the control and CSL experiment were 2.19 and 2.01 g/(L·h), respectively. Although the use of CSL resulted
in a 10% decrease in productivity, it is viewed that its application would be economical compared to P2 medium. Hence, CSL
may be used to replace the P2 medium. It was also demonstrated that inclusion of butyrate into the feed was beneficial to
the butanol fermentation. A control experiment produced 4.77 g/L of total ABE, and the experiment with supplemented sodium
butyrate produced 5.70 g/L of total ABE. The butanol concentration increased from 3.14 to 4.04 g/L. Inclusion of acetate in
the feed medium of the immobilized cell biofilm reactor was not found to be beneficial for the ABE fermentation, as reported
for the batch ABE fermentation.
Names are necessary to report factually on available data. However, the USDA neither guarantees nor warrants the standard
of the product, and the use of the names by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
138.
锂离子电池负极合金CoSn和Cu-Sn的制备与表征 总被引:9,自引:0,他引:9
CoSn alloy and Cu-Sn samples were synthesized by H2-reduction following solid-state reaction between Co(Ⅱ), Cu(Ⅱ), Sn(Ⅳ) and NaOH at ambient temperature. The samples were characterized by XRD, SEM. The results showed that CoSn alloy (80~200nm) is globe-shaped, ultrafine hexagonal material, and Cu-Sn alloy powder consists of two phases, i.e. Cu6Sn5 and Cu3Sn. Cu-Sn powder has spherical morphology and the particle size is estimated to be 60~70nm. The electrochemical performances of CoSn alloy and Cu-Sn powder were studied using lithium-ions model cell Li/LiPF6 (EC+DMC)/CoSn (or Cu-Sn). It was demonstrated the reversible discharge capacities for 10 cycles keep above 280mAh·g-1 for nanophase Cu-Sn, and 60mAh·g-1 for CoSn alloy. Differ-ential capacity plots showed that the reaction mechanisms of Cu-Sn with lithium were reversible. 相似文献
139.
研究了半导体隔片光电化学电池(SC-SEP)中光池溶液的pH、暗池溶液的氧化还原电对以及两池中的暗电极对电池的开路电压、光生电压、短路光电流和光伏安特性的影响。对它们的影响机制进行了初步分析。通过合理选择电池体系,SC-SEP的性能可比单隔室的光电化学电池(PEC)优越。 相似文献
140.
刘以训 《中国科学B辑(英文版)》1989,(12)
Several studies indicate that substances synthesized by granulosa cells are capableof regulating oocyte activity. We have studied the effect of factors synthesized by gran-ulosa cells on tPA activity of denuded oocytes using a co- culture system. The resultsshow that an FSH- dependent factor(s) synthesized by granulosa cells (but not by theca-interstitial cells) is capable of stimulating tPA activity of denuded oocytes. This findingis important for understanding hormonal regulation of oocyte tPA activity by mediatorssynthesized in granulosa cells. 相似文献