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101.
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The temperature coefficient of the surface energy has been calculated and the influence of the temperature on the anisotropy
of the surface energy has been demonstrated for crystal faces of the polymorphic phases of actinides. 相似文献
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Using a nano-injection method, we introduced phospholipids having different intrinsic geometries into single secretory cells and used single cell amperometry (SCA) and intracellular vesicle impact electrochemical cytometry (IVIEC) with nanotip electrodes to monitor the effects of intracellular incubation on the exocytosis process and vesicular storage. Combining tools, this work provides new information to understand the impact of intracellular membrane lipid engineering on exocytotic release, vesicular content and fraction of chemical release. We also assessed the effect of membrane lipid alteration on catecholamine storage of isolated vesicles by implementing another amperometric technique, vesicle impact electrochemical cytometry (VIEC), outside the cell. Exocytosis analysis reveals that the intracellular nano-injection of phosphatidylcholine and lysophosphatidylcholine decreases the number of released catecholamines, whereas phosphatidylethanolamine shows the opposite effect. These observations support the emerging hypothesis that lipid curvature results in membrane remodeling through secretory pathways, and also provide new evidence for a critical role of the lipid localization in modulating the release process. Interestingly, the IVIEC data imply that total vesicular content is also affected by in situ supplementation of the cells with some lipids, while, the corresponding VIEC results show that the neurotransmitter content in isolated vesicles is not affected by altering the vesicle membrane lipids. This suggests that the intervention of phospholipids inside the cell has its effect on the cellular machinery for vesicle release rather than vesicle structure, and leads to the somewhat surprising conclusion that modulating release has a direct effect on vesicle structure, which is likely due to the vesicles opening and closing again during exocytosis. These findings could lead to a novel regulatory mechanism for the exocytotic or synaptic strength based on lipid heterogeneity across the cell membrane.Amperometry and intracellular vesicle impact electrochemical cytometry with nanotip electrodes were used to monitor the effects on exocytosis and vesicular storage after nano-injection of phospholipids with different geometries into secretory cells. 相似文献
105.
Pressure and temperature are two important parameters in reservoir engineering. The fiber optic sensors can be used for permanent downhole monitoring. In this paper, we propose an extrinsic fiber Fabry-Perot interferometer (EFPI) sensor for pressure measurement with low sensitivity variation. The pressure sensitivity of EFPI sensor and of the fiber Bragg grating (FBG) sensors have been measured. The experimental pressure sensitivity for EFPI and FBG sensors are measured to be 2.75 × 10−8 1/kPa and 1.52 × 10−8 1/kPa, respectively. The temperature cross-sensitivity problem of the EFPI sensor has been solved by a new technique. The temperature sensitivity of EFPI sensor has been decreased to 1.2 × 10−6/°C, while the temperature sensitivity of non-compensated EFPI sensor has been measured to be 16.4 × 10−6/°C. The results show that the EFPI sensor has a higher pressure sensitivity and good capability to decrease temperature sensitivity in comparison to FBG sensor. 相似文献
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Ahmed Selmi Sobhi Hcini Hedi Rahmouni Aref Omri Mohamed Lamjed Bouazizi Abdessalem Dhahri 《Phase Transitions》2017,90(10):942-954
Spinel ferrite having composition Ni0.4Co0.4Mg0.2Fe2O4 was prepared by sol-gel method. X-ray diffraction result indicates that the ferrite sample has a cubic spinel type structure. FT-IR showed two absorption bands (ν1 and ν2) that are attributed to the stretching vibration of tetrahedral and octahedral sites. Complex impedance properties have been investigated in 200–420 K temperature range with varying frequency between 40 and 107 Hz. Frequency and temperature dependency of imaginary part of permittivity (?″) and dielectric loss (tanδ) has been discussed in terms of hopping of charge carriers between Fe2+ and Fe3+ ions. Activation energy has been estimated from both temperature dependency of dc conductivity and relaxation time data, which indicates that the relaxation process and conductivity have the same origin. Nyquist plots of impedance show semicircle arcs for sample and an electrical equivalent circuit has been proposed to explain the impedance results. 相似文献
108.
E. V. Shinkar’ O. V. Fedotova K. P. Pashchenko Ya. B. Aref’ev N. T. Berberova 《Russian Journal of Electrochemistry》2011,47(10):1172-1179
In this work, the routes of the redox reactions of chalcogenbiscyclanones and the products of their S-, O-, N-heterocyclization
in organic solvents were analyzed and validated. The influence of the nature of the heteroatoms and substituents on the redox
activity of S- and Se-containing biscyclanones, benzannelated thianthrenes, oxathianthrenes, and diazepine was established
based on electrochemical studies, ESR spectroscopy data, and the results of quantum chemical calculations 相似文献
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