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191.
Nesreen Alzoghoul Alsmadi Aniket S. Wadajkar Weina Cui Kytai T. Nguyen 《Journal of nanoparticle research》2011,13(12):7177-7186
The objective of this research was to compare the effects of two different surfactants on the physicochemical properties of
thermo-responsive poly(N-isopropylacrylamide-acrylamide-allylamine) (PNIPAAm-AAm-AH)-coated magnetic nanoparticles (MNPs). Sodium dodecyl sulfate
(SDS) as a commonly used surfactant in nanoparticle formulation process and Pluronic F127 as an FDA approved material were
used as surfactants to synthesize PNIPAAm-AAm-AH-coated MNPs (PMNPs). The properties of PMNPs synthesized using SDS (PMNPs-SDS)
and PF127 (PMNPs-PF127) were compared in terms of size, polydispersity, surface charge, drug loading efficiency, drug release
profile, biocompatibility, cellular uptake, and ligand conjugation efficiency. These nanoparticles had a stable core–shell
structure with about a 100-nm diameter and were superparamagnetic in behavior with no difference in the magnetic properties
in both types of nanoparticles. In vitro cell studies showed that PMNPs-PF127 were more cytocompatible and taken up more by
prostate cancer cells than that of PMNPs-SDS. Cells internalized with these nanoparticles generated a dark negative contrast
in agarose phantoms for magnetic resonance imaging. Furthermore, a higher doxorubicin release at 40 °C was observed from PMNPs-PF127,
and the released drugs were pharmacologically active in killing cancer cells. Finally, surfactant type did not affect the
conjugation efficiency to the nanoparticles when folic acid was used as a targeting ligand model. These results indicate that
PF127 might be a better surfactant to form polymer-coated magnetic nanoparticles for targeted and controlled drug delivery. 相似文献
192.
Using the Embedding Atom Method (EAM) for highly undercooled Ni3Al alloy, the melting point and the specific heat were studied by a molecular dynamics simulation. The simulation of melting
point was carried out by means of the sandwich method and the NVE ensemble method, and the results show a good agreement,
whereas are larger than the experimental value of 1663 K. This difference is attributed to the influence of surface melting
on experimental results, which causes the smaller measurements compared with the thermodynamic melting point. The simulated
specific heat of Ni3Al alloy weakly and linearly increases with the increase of undercooling in the temperature range from 800 K to 2000 K.
Supported by the National Natural Science Foundation of China (Grant No. 50395101) 相似文献
193.
We present a density matrix of a mesoscopic RLC circuits to make it possible to analyze the connection between the initial
condition and the certain temperature. Our results show that the quantum state evolution will be closely related to the initial
condition; the system evolves to generalized coherent state if it is in ground state initially, and evolves to squeezed state
if it is in excited state initially. In addition, we also obtain squeezed minimum uncertainty state with satisfying certain
condition in mesoscopic RLC circuit. 相似文献
194.
Thin solid polymer electrolytes based on polyethylene oxide (PEO) and silver triflate (AgCF3SO3) dispersed with various concentrations of aluminum oxide (Al2O3) nanoparticles have been prepared by solution casting technique. These thin polymer films are found to have thickness of
the order of 30 to 100 μm. The X-ray diffraction (XRD) patterns have indicated the amorphous nature of the polymer electrolyte.
The differential scanning calorimeter (DSC) traces showed slight change in the glass transition temperature (T
g) whereas the degree of crystallization (X
c) decreases markedly due to the addition of alumina nanoparticles. Fourier transform infrared (FTIR) spectral analysis of
all these samples has revealed the presence of absorption bands around 1,000 cm−1; thus indicating the complexation of silver ions with oxygen in PEO. Employing the Wagner’s polarization technique as the
standard method, the total ionic transference number for the complexed polymer electrolyte was found to be approximately unity
thereby revealing that the significant contribution to electrical conduction was due to ions only.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, December 7–9,
2006 相似文献
195.
Isotopic liftings of algebraic structures are investigated in the context of Clifford algebras, where it is defined a new
product involving an arbitrary, but fixed, element of the Clifford algebra. This element acts as the unit with respect to
the introduced product, and is called isounit. We construct isotopies in both associative and non-associative arbitrary algebras, and examples of these constructions are
exhibited using Clifford algebras, which although associative, can generate the octonionic, non-associative, algebra. The
whole formalism is developed in a Clifford algebraic arena, giving also the necessary pre-requisites to introduce isotopies
of the exterior algebra. The flavor hadronic symmetry of the six u,d,s,c,b,t quarks is shown to be exact, when the generators of the isotopic Lie algebra
are constructed, and the unit of the isotopic Clifford algebra is shown to be a function of the six quark masses. The limits
constraining the parameters, that are entries of the representation of the isounit in the isotopic group SU(6), are based
on the most recent limits imposed on quark masses. 相似文献
196.
We have calculated the one-neutron absorption cross-section and the longitudinal momentum distribution of the core fragment
coming out from the breakup of 11Be and 19C on 9Be target at 63 MeV/A and 88 MeV/A beam energies respectively. The reaction mechanism is treated within the framework of the
eikonal approximation. The effective range of the nuclear interaction between the core and the valence neutron within the
projectile has been determined by comparing the predicted stripping cross-section with the recently measured one. The effective
range for 19C has been found to be smaller than that for 11Be. It qualitatively indicates that 19C is slightly more halo than 11Be. The smaller width, predicted as well as measured, of the LMD of 18C than 10Be also strengthens this fact. The experimental data concerning the LMD of core fragments have been well represented.
相似文献
197.
Marco Castrillón López Jaime Muñz Masquó 《International Journal of Theoretical Physics》2007,46(4):1020-1026
It is proved that the Euler–Lagrange equations of a Yang-Mills type Lagragian is independent with respect to the chosen pairing
in the Lie algebra. Moreover, the Hamilton-Cartan equations of these Lagrangians are obtained and proved to be also independent
with respect to the pairing.
PACS Numbers 2003: 02.20.Qs, 02.20.Sv, 02.20.Tw, 02.40.Ma, 02.40.Vh, 11.10.Ef, 11.15.Kc
Mathematics Subject Classification 2000: Primary 70S15, Secondary 58A20, 58E15, 58E30, 70S05, 70S10, 81T13 相似文献
198.
We present the study of exact inhomogeneous cosmological solutions to a four-dimensional low energy limit of string theory
containing non-minimal interacting electromagnetic, dilaton and axion fields. We focus at Einstein-Rosen solutions of Einstein-Maxwell-dilaton-axion
equations. Several cases are analyzed and some of them have asymptotically velocity-term dominated (AVTD) singularities. 相似文献
199.
Solar System tests give nowadays constraints on the estimated value of the cosmological constant, which can be accurately
derived from different experiments regarding gravitational redshift, light deflection, gravitational time-delay and geodesic
precession. Assuming that each reasonable theory of gravitation should satisfy Solar System tests, we use these limits on
the estimated value of the cosmological constant to constrain extended theories of Gravity, which are nowadays studied as
possible theories for cosmological models and provide viable solutions to the cosmological constant problem and the explanation
of the present acceleration of the Universe. We obtain that the estimated values, from Solar System tests, for the parameters
appearing in the extended theories of Gravity are orders of magnitude bigger than the values obtained in the framework of
cosmologically relevant theories. 相似文献
200.
Omar Qasaimeh 《Optical and Quantum Electronics》2017,49(3):109
The characteristics of optical bistability in quantum dot vertical cavity semiconductor optical amplifier integrated with MEMS membrane have been investigated, and a closed-form model is derived taking into account the effect of the quantum dot discrete states and the membrane deflection and reflectivity. We show that small membrane deflection significantly adjusts the resonant wavelength, the contrast ratios and the hysteresis width. The shape of the input–output characteristics of the device can be adjusted to display clockwise, butterfly and counterclockwise hysteresis loops depending on the membrane deflection and the initial wavelength detuning. Our analysis reveals that the contrast ratios of the upper and lower bistable levels are totally different. Also, it has been shown that the characteristics of the bistability are strong function of the active layer linewidth enhancement factor and the membrane reflectivity. 相似文献