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21.
A new class of multifunctional nanoparticles that combine properties of polymeric drug carriers, ultrasound imaging contrast agents, and enhancers of ultrasound-mediated drug delivery has been developed. At room temperature, the developed systems comprise perfluorocarbon nanodroplets stabilized by the walls made of biodegradable block copolymers. Upon heating to physiological temperatures, the nanodroplets convert into nano/microbubbles. The phase state of the systems and bubble size may be controlled by the copolymer/perfluorocarbon volume ratio. Upon intravenous injections, a long-lasting, strong and selective ultrasound contrast is observed in the tumor volume indicating nanobubble extravasation through the defective tumor microvasculature, suggesting their coalescence into larger, highly echogenic microbubbles in the tumor tissue. Under the action of tumor-directed ultrasound, microbubbles cavitate and collapse resulting in a release of the encapsulated drug and dramatically enhanced intracellular drug uptake by the tumor cells. This effect is tumor-selective; no accumulation of echogenic microbubbles is observed in other organs. Effective chemotherapy of the MDA MB231 breast cancer tumors has been achieved using this technique. 相似文献
22.
23.
Anne Boutet De Monvel-Berthier Louis Boutet De Monvel Gilles Lebeau 《Journal d'Analyse Mathématique》1992,58(1):39-60
Sans résumé
Dedicated to Professor Shmuel Agmon 相似文献
24.
Although the classical Fractional Brownian Motion is often used to describe porosity,
it is not adapted to anisotropic situations. In the present work, we study a class of Gaussian
fields with stationary increments and spectral density. They present asymptotic self-similarity
properties and are good candidates to model a homogeneous anisotropic material, or its radiographic
images. Unfortunately, the paths of all Gaussian fields with stationary increments have the
same apparent regularity in all directions (except at most one). Hence we propose here a procedure
to recover anisotropy from one realization: computing averages over all the hyperplanes which
are orthogonal to a fixed direction, we get a process whose Hölder regularity depends explicitly on
the asymptotic behavior of the spectral density in this direction. 相似文献
25.
We prove Anderson localization and strong dynamical localization for random surface models in
\mathbbRd \mathbb{R}^d . 相似文献
26.
A 16-parameter force field for OCS based on curvilinear coordinates is presented in table 2 and the agreement between observed and calculated transitions and rotational constants is indicated in tables 4, 5 and 6. The computational approach differs from that of Morino and Nakagawa [2] and similar work on other molecules by other authors, in that perturbation theory is eschewed and the calculated vibrational transitions and rotational constants are derived via the numerical solution of a large matrix. The usual parameters xij , yijk , α i B and γ ij B are thereby rendered inappropriate intermediates. The approach also leads to estimates of B e - B 0 for each isotopic species and thence suggests equilibrium distances r CO = 1·155386(21) Å and r CS = 1·562021(17) Å. 相似文献
27.
Ondeykal JG Herath KB Jayasuriya H Polishook JD Bills GF Dombrowski AW Mojena M Koch G DiSalvo J DeMartino J Guan Z Nanakorn W Morenberg CM Balick MJ Stevenson DW Slattery M Borris RP Singh SB 《Molecular diversity》2005,9(1-3):123-129
The chemokines (CXCL9, CXCL10 and CXCL11) and associated CXCR3 receptor are expressed during the inflammatory process from multiple sclerosis, atherosclerosis or organ transplantation resulting in the recruitment of lymphocytes leading to tissue damage. It is hypothesized that blocking of the ligand/CXCR3 receptor interaction has potential to provide opportunity for development of agents that would block tissue rejection. In this paper, four classes of natural product inhibitors (IC50 ranging 0.1–41 M) have been described that block the CXCR3 receptor interaction of IP-10 ligand. These include a cyclic thiopeptide (duramycin), polyketide glycosides (roselipins), steroidal glycosides (hypoglausin A and dioscin) and a novel alkyl pyridinium alkaloid that were isolated by bioassay-guided fractionation of the organic extracts derived from actinomycete, fungal, plant and marine sources and discovered using 125 I IP-10/CXCR3 binding assay. Duramycin was the most potent with an IC50 of 0.1 M. Roselipins 2A, 2B and 1A showed IC50 values of 14.6, 23.5, and 41 M, respectively. Diosgenin glycosides dioscin, hypoglaucin A and kallstroemin D exhibited IC50 values of 2.1, 0.47 and 3 M, respectively. A novel cyclic 3-alkyl pyridinium salt isolated from a sponge displayed a binding IC50 of 0.67 M. 相似文献
28.
Patrick C. Chaumet Anne Sentenac Anne-Laure Fehrembach 《Optical and Quantum Electronics》2017,49(2):71
In this paper, we study the performances of the Dipole Discrete Approximation method for modelling the reflectivity of a highly resonant, 3D subwavelength patterned structure extending over tens of thousands wavelength square. The computation time of the whole reflectivity spectrum (80 wavelengths) was about 3 h on a computer and requires about 1.5 GB in memory. These performances make the DDA an unique numerical tool for modelling the scattering by large 3D structures supporting long-range interactions. 相似文献
29.
A system of two coupled oscillators, each of them coupled to an independent reservoir, is analysed. The analytical solution of the non-rotating wave master equation is obtained in the high-temperature and weak coupling limits. No thermal entanglement is found in the high-temperature limit. In the weak coupling limit the system converges to an entangled non-equilibrium steady state. A critical temperature for the appearance of quantum correlations is found. 相似文献
30.
Ying Li Anne Sylvie Fabiano-Tixier Valérie Tomao Giancarlo Cravotto Farid Chemat 《Ultrasonics sonochemistry》2013,20(1):12-18
A green, inexpensive and easy-to-use method for carotenoids extraction from fresh carrots assisted by ultrasound was designed in this work. Sunflower oil was applied as a substitute to organic solvents in this green ultrasound-assisted extraction (UAE): a process which is in line with green extraction and bio-refinery concepts. The processing procedure of this original UAE was first compared with conventional solvent extraction (CSE) using hexane as solvent. Moreover, the UAE optimal conditions for the subsequent comparison were optimized using response surface methodology (RSM) and ultra performance liquid chromatography – diode array detector – mass spectroscopy (UPLC–DAD–MS). The results showed that the UAE using sunflower as solvent has obtained its highest β-carotene yield (334.75 mg/l) in 20 min only, while CSE using hexane as solvent obtained a similar yield (321.35 mg/l) in 60 min. The green UAE performed under optimal extraction conditions (carrot to oil ratio of 2:10, ultrasonic intensity of 22.5 W cm?2, temperature of 40 °C and sonication time of 20 min) gave the best yield of β-carotene. 相似文献