312,193 research outputs found
Theoretical and Experimental Adsorption Studies of Polyelectrolytes on an Oppositely Charged Surface
Using self-assembly techniques, x-ray reflectivity measurements, and computer
simulations, we study the effective interaction between charged polymer rods
and surfaces. Long-time Brownian dynamics simulations are used to measure the
effective adhesion force acting on the rods in a model consisting of a planar
array of uniformly positively charged, stiff rods and a negatively charged
planar substrate in the presence of explicit monovalent counterions and added
monovalent salt ions in a continuous, isotropic dielectric medium. This
electrostatic model predicts an attractive polymer-surface adhesion force that
is weakly dependent on the bulk salt concentration and that shows fair
agreement with a Debye-Huckel approximation for the macroion interaction at
salt concentrations near 0.1 M. Complementary x-ray reflectivity experiments on
poly(diallyldimethyl ammonium) chloride (PDDA) monolayer films on the native
oxide of silicon show that monolayer structure, electron density, and surface
roughness are likewise independent of the bulk ionic strength of the solution.Comment: Revtex, prb format; uses amssym
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Neuroinflammation is a putative target for the prevention and treatment of perioperative neurocognitive disorders.
IntroductionThe demographics of aging of the surgical population has increased the risk for perioperative neurocognitive disorders in which trauma-induced neuroinflammation plays a pivotal role.Sources of dataAfter determining the scope of the review, the authors used PubMed with select phrases encompassing the words in the scope. Both preclinical and clinical reports were considered.Areas of agreementNeuroinflammation is a sine qua non for development of perioperative neurocognitive disorders.Areas of controversyWhat is the best method for ameliorating trauma-induced neuroinflammation while preserving inflammation-based wound healing.Growing pointsThis review considers how to prepare for and manage the vulnerable elderly surgical patient through the entire spectrum, from preoperative assessment to postoperative period.Areas timely for developing researchWhat are the most effective and safest interventions for preventing and/or reversing Perioperative Neurocognitive Disorders
Electromagnetic Energy for a Charged Kerr Black Hole in a Uniform Magnetic Field
With the Komar mass formula we calculate the electromagnetic energy for a
charged Kerr black hole in a uniform magnetic field. We find that the total
electromagnetic energy takes the minimum when the Kerr black hole possesses a
non-zero net charge where is the strength of the
magnetic field, is the angular momentum of the black hole, is a
dimensionless parameter determined by the spin of the black hole.Comment: 9 pages, 1 figur
Exploring the Latest Union2 SNIa Dataset by Using Model-Independent Parametrization Methods
We explore the cosmological consequences of the recently released Union2
sample of 557 Type Ia supernovae (SNIa). Combining this latest SNIa dataset
with the Cosmic microwave background (CMB) anisotropy data from the Wilkinson
Microwave Anisotropy Probe 7 year (WMAP7) observations and the baryon acoustic
oscillation (BAO) results from the Sloan Digital Sky Survey (SDSS) Data Release
7 (DR7), we measure the dark energy density function as a free function of redshift. Two
model-independent parametrization methods (the binned parametrization and the
polynomial interpolation parametrization) are used in this paper. By using the
statistic and the Bayesian information criterion, we find that the
current observational data are still too limited to distinguish which
parametrization method is better, and a simple model has advantage in fitting
observational data than a complicated model. Moreover, it is found that all
these parametrizations demonstrate that the Union2 dataset is still consistent
with a cosmological constant at 1 confidence level. Therefore, the
Union2 dataset is different from the Constitution SNIa dataset, which more
favors a dynamical dark energy.Comment: 11 pages, 8 figures, 2 tables, accepted for publication in PR
Classification of the Entangled states L\times N\times N
We presented a general classification scheme for the tripartite entangled system under stochastic local operation and classical
communication. The whole classification procedure consists of two correlated
parts: the simultaneous similarity transformation of a commuting matrix pair
into a canonical form and the study of internal symmetry of parameters in the
canonical form. Based on this scheme, a concrete example of entanglement
classification for a system is given.Comment: 21 pages; published in Phys. Rev.
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