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111.
Monitoring and Quantifying the Passive Transport of Molecules Through Patch–Clamp Suspended Real and Model Cell Membranes 下载免费PDF全文
Dr. Pierluca Messina Dr. Frédéric Lemaître Prof. François Huet Dr. Kieu An Ngo Dr. Vincent Vivier Prof. Eric Labbé Dr. Olivier Buriez Prof. Christian Amatore 《Angewandte Chemie (International ed. in English)》2014,53(12):3192-3196
Transport of active molecules across biological membranes is a central issue for the success of many pharmaceutical strategies. Herein, we combine the patch–clamp principle with amperometric detection for monitoring fluxes of redox‐tagged molecular species across a suspended membrane patched from a macrophage. Solvent‐ and protein‐free lipid bilayers (DPhPC, DOPC, DOPG) patched from single‐wall GUV have been thoroughly investigated and the corresponding fluxes measurements quantified. The quality of the patches and their proper sealing were successfully characterized by electrochemical impedance spectroscopy. This procedure appears versatile and perfectly adequate to allow the investigation of transport and quantification of the transport properties through direct measurement of the coefficients of partition and diffusion of the compound in the membrane, thus offering insight on such important biological and pharmacological issues. 相似文献
112.
Dr. Tao Liu Dr. Aline Nonat Dr. Maryline Beyler Dr. Martín Regueiro‐Figueroa Dr. Katia Nchimi Nono Dr. Olivier Jeannin Dr. Franck Camerel Dr. François Debaene Dr. Sarah Cianférani‐Sanglier Prof. Raphaël Tripier Dr. Carlos Platas‐Iglesias Dr. Loïc J. Charbonnière 《Angewandte Chemie (International ed. in English)》2014,53(28):7259-7263
Lanthanide complexes (Ln=Eu, Tb, and Yb) that are based on a C2‐symmetric cyclen scaffold were prepared and characterized. The addition of fluoride anions to aqueous solutions of the complexes resulted in the formation of dinuclear supramolecular compounds in which the anion is confined into the cavity that is formed by the two complexes. The supramolecular assembly process was monitored by UV/Vis absorption, luminescence, and NMR spectroscopy and high‐resolution mass spectrometry. The X‐ray crystal structure of the europium dimer revealed that the architecture of the scaffold is stabilized by synergistic effects of the Eu? F? Eu bridging motive, π stacking interactions, and a four‐component hydrogen‐bonding network, which control the assembly of the two [EuL] entities around the fluoride ion. The strong association in water allowed for the luminescence sensing of fluoride down to a detection limit of 24 nM . 相似文献
113.
应用电喷雾(ESI)质谱及其多级串联质谱(MS~n)技术研究了三个氨基酸衍 生物N-(N-亚甲基-2-吡咯烷酮)-缬氨酸(PMV),N,N-二-(N-亚甲基-2-吡咯烷 酮)-亮氨酸(PML)和N,N-二-(N-亚甲基-2-吡咯烷酮)-β-丙氨酸(PMA)在电 喷雾条件下的质谱行为。在此条件下三个氨基酸衍生物PMV,PML和PMA可以质子化 形式PMVH~+,PMLH~+和PMAH~+存在,并且检测到它们的Na~+和K~+的加合物。在电 喷雾条件下PMV,PML和PMA优先采取C-N键的断裂,并且通过分子间的氢键作用形成 了许多二聚和三聚物种。 相似文献
114.
Kobra Mahdavipour Mahshid Khazaei Shadfar Hossein Rangani Jahromi Roberto Morandotti Rosario Lo Franco 《Entropy (Basel, Switzerland)》2022,24(3)
A witness of non-Markovianity based on the Hilbert–Schmidt speed (HSS), a special type of quantum statistical speed, has been recently introduced for low-dimensional quantum systems. Such a non-Markovianity witness is particularly useful, being easily computable since no diagonalization of the system density matrix is required. We investigate the sensitivity of this HSS-based witness to detect non-Markovianity in various high-dimensional and multipartite open quantum systems with finite Hilbert spaces. We find that the time behaviors of the HSS-based witness are always in agreement with those of quantum negativity or quantum correlation measure. These results show that the HSS-based witness is a faithful identifier of the memory effects appearing in the quantum evolution of a high-dimensional system with a finite Hilbert space. 相似文献
115.
Sébastien Aumaître Kirone Mallick François Pétrélis 《Journal of statistical physics》2006,123(4):909-927
A bifurcating system subject to multiplicative noise can exhibit on–off intermittency close to the instability threshold. For a canonical system, we discuss the dependence of this intermittency on the Power Spectrum Density (PSD) of the noise. Our study is based on the calculation of the Probability Density Function (PDF) of the unstable variable. We derive analytical results for some particular types of noises and interpret them in the framework of on-off intermittency. Besides, we perform a cumulant expansion (N. G. van Kampen, 24, 171 (1976).) for a random noise with arbitrary power spectrum density and we show that the intermittent regime is controlled by the ratio between the departure from the threshold and the value of the PSD of the noise at zero frequency. Our results are in agreement with numerical simulations performed with two types of random perturbations: colored Gaussian noise and deterministic fluctuations of a chaotic variable. Extensions of this study to another, more complex, system are presented and the underlying mechanisms are discussed.
PACS Number: 05.40.-a, 05.45.-a, 91.25.-r 相似文献
116.
117.
We describe a protocol for distilling maximally entangled bipartite states between random pairs of parties from those sharing a tripartite W state |W=(1/sqrt[3])(|100+|010+|001)(ABC), and show that the total distillation rate E(t)(infinity) [the total number of Einstein-Podolsky-Rosen (EPR) pairs distilled per W, irrespective of who shares them] may be done at a higher rate than EPR distillation between specified pairs of parties. Specifically, the optimal rate for distillation to specified parties has been previously shown to be 0.92 EPR pairs per W, while our protocol can asymptotically distill 1 EPR pair per W between random pairs of parties, which we conjecture to be optimal. We thus demonstrate a tradeoff between overall distillation rate and final distribution of EPR pairs. We further show that there exist states with fixed lower-bounded E(t)(infinity), but arbitrarily small distillable entanglement for specified parties. 相似文献
118.
Temperature dependent behavior of the responsivity of InAs/GaAs quantum dot infrared photodetectors was investigated with detailed measurement of the current gain. The current gain varied about two orders of magnitude with 100 K temperature change. Meanwhile, the change in quantum efficiency is within a factor of 10. The dramatic change of the current gain is explained by the repulsive coulomb potential of the extra carriers in the QDs. With the measured current gain, the extra carrier number in QDs was calculated. More than one electron per QD could be captured as the dark current increases at 150 K. The extra electrons in the QDs elevated the Fermi level and changed the quantum efficiency of the QDIPs. The temperature dependence of the responsivity was qualitatively explained with the extra electrons. 相似文献
119.
A modified Bridgman method is described, which makes it possible to prepare homogeneous BiTeI crystals using excess iodine. At room temperature the values of the electrical conductivity of the crystals range around 2000 –1 cm–1, the Hall constant value about 0·09 cm–3 coul–1, the Seebeck coefficient about 50 V K–1. In connection with the assumption of super-stoichiometric iodine content we expect there exist point defects in the crystals, where Te atoms are replaced with I atoms, which gives rise to electric conductivity. On the basis of the temperature dependence of the electron mobility one can suppose a mixed mechanism of the scattering of the free carriers by the acoustic branch of lattice vibrations and by ionized impurities. 相似文献
120.
Libration point trajectory design 总被引:1,自引:0,他引:1
Orbits about the Sun–Earth L
1 and L
2 libration points have become very popular for space physics and astrophysics missions. Due to the hyperbolicity of the region
of phase space where these orbits are found, they are difficult to compute and analyze. The invariant manifold structure provided
by dynamical systems theory has been useful to compute transfer trajectories between orbits. These methods are very promising
and require further development. This systematic approach is a great improvement from the difficult and labor-intensive numerical
search methods currently popular in the astrodynamics community for studying these orbits. The geometric constraints and mission
critical issues are discussed to give the numerical dynamical systems community some insight into the practical considerations
and important problems of interest to the space mission designers. It is hoped that this communication will lead to more fruitful
exchanges between the two communities.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献