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81.
Farah Abdallah Serge Nicaise Julie Valein Ali Wehbe 《Comptes Rendus Mathematique》2012,350(1-2):29-34
In this Note, we consider the approximation of two coupled wave equations with internal damping. Our goal is to damp the spurious high frequency modes by introducing numerical viscosity terms in the approximation scheme. With these viscosity terms, we show the exponential or polynomial decay of the discrete scheme when the continuous problem has such a decay (since the spectrum of the spatial operator associated with the undamped system satisfies the generalized gap condition). 相似文献
82.
Effect of particle size distribution on magnetic behavior of nanoparticles with uniaxial anisotropy 下载免费PDF全文
S Rizwan Ali Farah Naz Humaira Akber M Naeem S Imran Ali S Abdul Basit M Sarim Sadaf Qaseem 《中国物理 B》2018,(9)
The effect of particle size distribution on the field and temperature dependence of the hysteresis loop features like coercivity(H_C), remanence(M_R), and blocking temperature(T_B) is simulated for an ensemble of single domain ferromagnetic nanoparticles with uniaxial anisotropy. Our simulations are based on the two-state model for T T_B and the metropolis Monte-Carlo method for T T_B. It is found that the increase in the grain size significantly enhances H_C and T_B. The presence of interparticle exchange interaction in the system suppresses H_C but causes MRto significantly increase.Our results show that the parameters associated with the particle size distribution(D_(d,δ)) such as the mean particle size d and standard-deviation δ play key roles in the magnetic behavior of the system. 相似文献
83.
Abdikani Omar Farah Ryan Archibald Morgan J. Rodriguez Antonio Moreno Blaise Dondji Timothy K. Beng 《Tetrahedron letters》2018,59(38):3495-3498
A flexible and cost-effective method for the highly functional group-compatible and site-selective cross-coupling of readily affordable α-chloro-β-formyltetrahydropyridines has been developed, under nickel or cobalt catalysis, leading to the rapid synthesis of 2,3,5,6-tetrasubstituted dehydropiperidines bearing α-amino allylic stereocenters. Cobalt-catalyzed reductive cross-coupling of chloro enaminals with electronically-diverse bromostyrenes as coupling partners proceeds in good yields and with high E/Z selectivity to afford Diels-Alder-suitable cross-conjugated 1,3-dienes. 相似文献
84.
Mesoporous γ‐Iron Oxide Nanoparticles for Magnetically Triggered Release of Doxorubicin and Hyperthermia Treatment 下载免费PDF全文
Dr. Farah Benyettou Jaen Alonso Ocadiz Flores Dr. Florent Ravaux Dr. Rachid Rezgui Dr. Mustapha Jouiad Samer I. Nehme Rajesh Kumar Parsapur Prof. John‐Carl Olsen Prof. Parasuraman Selvam Prof. Ali Trabolsi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):17020-17028
Mesoporous iron‐oxide nanoparticles (mNPs) were prepared by using a modified nanocasting approach with mesoporous carbon as a hard template. mNPs were first loaded with doxorubicin (Dox), an anticancer drug, and then coated with the thermosensitive polymer Pluronic F108 to prevent the leakage of Dox molecules from the pores that would otherwise occur under physiological conditions. The Dox‐loaded, Pluronic F108‐coated system (Dox@F108‐mNPs) was stable at room temperature and physiological pH and released its Dox cargo slowly under acidic conditions or in a sudden burst with magnetic heating. No significant toxicity was observed in vitro when Dox@F108‐mNPs were incubated with noncancerous cells, a result consistent with the minimal internalization of the particles that occurs with normal cells. On the other hand, the drug‐loaded particles significantly reduced the viability of cervical cancer cells (HeLa, IC50=0.70 μm ), wild‐type ovarian cancer cells (A2780, IC50=0.50 μm ) and Dox‐resistant ovarian cancer cells (A2780/AD, IC50=0.53 μm ). In addition, the treatment of HeLa cells with both Dox@F108‐mNPs and subsequent alternating magnetic‐field‐induced hyperthermia was significantly more effective at reducing cell viability than either Dox or Dox@F108‐mNP treatment alone. Thus, Dox@F108‐mNPs constitute a novel soft/hard hybrid nanocarrier system that is highly stable under physiological conditions, temperature‐responsive, and has chemo‐ and thermotherapeutic modes of action. 相似文献
85.
Farah Benyettou Nawel Kaddour Thirumurugan Prakasam Gobinda Das Sudhir Kumar Sharma Sneha Ann Thomas Fadia Bekhti-Sari Jamie Whelan Mohammed A. Alkhalifah Mostafa Khair Hassan Traboulsi Renu Pasricha Ramesh Jagannathan Nassima Mokhtari-Soulimane Felipe Gndara Ali Trabolsi 《Chemical science》2021,12(17):6037
With diabetes being the 7th leading cause of death worldwide, overcoming issues limiting the oral administration of insulin is of global significance. The development of imine-linked-covalent organic framework (nCOF) nanoparticles for oral insulin delivery to overcome these delivery barriers is herein reported. A gastro-resistant nCOF was prepared from layered nanosheets with insulin loaded between the nanosheet layers. The insulin-loaded nCOF exhibited insulin protection in digestive fluids in vitro as well as glucose-responsive release, and this hyperglycemia-induced release was confirmed in vivo in diabetic rats without noticeable toxic effects. This is strong evidence that nCOF-based oral insulin delivery systems could replace traditional subcutaneous injections easing insulin therapy.We report the successful use of a gastro-resistant covalent organic framework for in vivo oral delivery of insulin. 相似文献
86.
The squarate complexes of Eu3+, Tb3+ and Tm3+ in aqueous solutions of 0.05M, 0.075M and 0.1M ionic strength are studied using the solvent extraction method. Effects of
changes in the ionic strength on the stability constants of the complexes formed are discussed. 相似文献
87.
N. Farouk M. A. Motaleb H. A. Shweeta K. Farah M. T. Kolaly 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):405-410
Summary [125I]iodepidepride, (s)-(-)-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[125I]-iodo-2,3-dimethoxybenzamide is the iodine substituted analogue of isoremoxipride, both of which are very potent dopamine
D2-antagonists. Epidepride was radioiodinated using different oxidizing agents such as chloramine-T, iodogen, iodogen glass
frit and hydrogen peroxide. Chloramine-T is a powerful oxidizing agent compared to both iodogen and hydrogen peroxide so that
the side products, especially the chlorinated epidepride, decreases the radiochemical yield. This chlorinated epidepride is
minimized in the case of iodogen and iodogen glass frit and are not observed in case of the non-chlorinated oxidizing agent
hydrogen peroxide. TLC and HPLC were used to analyze the reaction components and to estimate both the radiochemical yield
and purity. The reaction parameters such as reaction time, pH, epidepride and oxidizing agent concentrations and the stabilty
of the final product were studied to optimize the radiochemical yield and purity. The optimized radiochemical yield was about
90% and the radiochemical purity of the final product was 99.9%. 相似文献
88.
Das K Ashby KD Smirnov AV Reinach FC Petrich JW Farah CS 《Photochemistry and photobiology》1999,70(5):719-730
Tropomyosin mutants containing either tryptophan (122W), 5-hydroxytryptophan (5OH122W) or 7-azatryptophan (7N122W) have been expressed in Escherichia coli and their fluorescence properties studied. The fluorescent amino acids were located at position 122 of the tropomyosin primary sequence, corresponding to a solvent-exposed position c of the coiled-coil heptapeptide repeat. The emission spectrum of the probe in each mutant is blue-shifted slightly with respect to that of the probe in water. The fluorescence anisotropy decays are single exponential, with a time constant of 2-3 ns while the fluorescence lifetimes of the probes incorporated into the proteins, in water, are nonexponential. Because tryptophan in water has an intrinsic nonexponential fluorescence decay, it is not surprising that the fluorescence decay of 122W is well described by a triple exponential. The fluorescence decays in water of the nonnatural amino acids 5-hydroxytryptophan and 7-azatryptophan (when emission is collected from the entire band) are single exponential. Incorporation into tropomyosin induces triple-exponential fluorescence decay in 5-hydroxytryptophan and double-exponential fluorescence decay in 7-azatryptophan. The range of lifetimes observed for 5-hydroxyindole and 5-hydroxytryptophan at high pH and in the nonaqueous solvents were used as a base with which to interpret the lifetimes observed for the 5OH122W and indicate that the chromophore exists in several solvent environments in both its protonated and unprotonated forms in 5OH122W. 相似文献
89.
Sorption of Th, Pa, U, Np and Pu on silica gel from HNO3, HCl and HCl−ROH solutions was investigated. Equilibrium studies indicated sorption behaviour to vary greatly with the acid
used. In mixtures of HCl with different alcohols, distribution coefficints were found to depend on alcohol percentage as well
as on acidity. Results were discussed and conditions for possible separations were indicated. 相似文献
90.
Luiz G. Farah 《Journal of Evolution Equations》2016,16(1):193-208
We consider the supercritical inhomogeneous nonlinear Schrödinger equationwhere \({(2 - b)/N < \sigma < (2 - b)/(N-2)}\) and \({0 < b < \rm min\{2,N\}}\). We prove a Gagliardo–Nirenberg-type estimate and use it to establish sufficient conditions for global existence and blow-up in \({H^1(\mathbb{R}^N)}\).
相似文献
$$i\partial_t u+\Delta u+|x|^{-b}|u|^{2\sigma}u=0,$$