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DNA sensing by electrocatalysis with hemoglobin
Electrocatalysis offers a means of electrochemical signal amplification, yet in DNA-based sensors, electrocatalysis has required high-density DNA films and strict assembly and passivation conditions. Here, we describe the use of hemoglobin as a robust and effective electron sink for electrocatalysis in DNA sensing on low-density DNA films. Protein shielding of the heme redox center minimizes direct reduction at the electrode surface and permits assays on low-density DNA films. Electrocatalysis with methylene blue that is covalently tethered to the DNA by a flexible alkyl chain linkage allows for efficient interactions with both the base stack and hemoglobin. Consistent suppression of the redox signal upon incorporation of a single cytosine-adenine (CA) mismatch in the DNA oligomer demonstrates that both the unamplified and the electrocatalytically amplified redox signals are generated through DNA-mediated charge transport. Electrocatalysis with hemoglobin is robust: It is stable to pH and temperature variations. The utility and applicability of electrocatalysis with hemoglobin is demonstrated through restriction enzyme detection, and an enhancement in sensitivity permits femtomole DNA sampling
Ground-state properties and symmetry energy of neutron-rich and neutron-deficient Mg isotopes
A comprehensive study of various ground-state properties of neutron-rich and
neutron-deficient Mg isotopes with =20-36 is performed in the framework of
the self-consistent deformed Skyrme-Hartree-Fock plus BCS method. The
correlation between the skin thickness and the characteristics related with the
density dependence of the nuclear symmetry energy is investigated for this
isotopic chain following the theoretical approach based on the coherent density
fluctuation model and using the Brueckner energy-density functional. The
results of the calculations show that the behavior of the nuclear charge radii
and the nuclear symmetry energy in the Mg isotopic chain is closely related to
the nuclear deformation. We also study, within our theoretical scheme, the
emergence of an "island of inversion" at neutron-rich Mg nucleus, that
was recently proposed from the analyses of spectroscopic measurements of
Mg low-lying energy spectrum and the charge rms radii of all magnesium
isotopes in the shell.Comment: 13 pages, 13 figures, to be published in Physical Review
On the Thermodynamic Limit in Random Resistors Networks
We study a random resistors network model on a euclidean geometry \bt{Z}^d.
We formulate the model in terms of a variational principle and show that, under
appropriate boundary conditions, the thermodynamic limit of the dissipation per
unit volume is finite almost surely and in the mean. Moreover, we show that for
a particular thermodynamic limit the result is also independent of the boundary
conditions.Comment: 14 pages, LaTeX IOP journal preprint style file `ioplppt.sty',
revised version to appear in Journal of Physics
Narrative structure in the works of Frederic Rzewski
This thesis examines the compositional strategies Rzewski applies to affect his audience’s expectations so that the experience of the work parallels the political and philosophical ideas within it. Employing musical narrative theory as a way to characterize the process of expectation that can guide the perception of musical meaning, I explore how Rzewski’s pieces support or reject interpretation through a musical dramatic trajectory in ways that reflect the concepts behind the work to argue that: 1) Rzewski’s early variation works follow a linear narrative whose sequence of musical transvaluation conveys dynamics of socio-political problems and suggest solutions through collective action; 2) Rzewski’s improvisational compositions frustrate the development of expectations in an anti-narrative form paralleling his interest in the discontinuity hidden behind surface perception of reality; and 3) Rzewski’s nonlinear narrative Iraq War variation pieces combine continuity and interruption to merge his anti-teleological perspective on life with war
Nuclear skin emergence in Skyrme deformed Hartree-Fock calculations
A study of the charge and matter densities and the corresponding rms radii
for even-even isotopes of Ni, Kr, and Sn has been performed in the framework of
deformed self-consistent mean field Skyrme HF+BCS method. The resulting charge
radii and neutron skin thicknesses of these nuclei are compared with available
experimental data, as well as with other theoretical predictions. The formation
of a neutron skin, which manifests itself in an excess of neutrons at distances
greater than the radius of the proton distribution, is analyzed in terms of
various definitions. Formation of a proton skin is shown to be unlikely. The
effects of deformation on the neutron skins in even-even deformed nuclei far
from the stability line are discussed.Comment: 16 pages, 17 figures, to be published in Physical Review
Temperature dependence of the volume and surface contributions to the nuclear symmetry energy within the coherent density fluctuation model
The temperature dependence of the volume and surface components of the
nuclear symmetry energy (NSE) and their ratio is investigated in the framework
of the local density approximation (LDA). The results of these quantities for
finite nuclei are obtained within the coherent density fluctuation model
(CDFM). The CDFM weight function is obtained using the temperature-dependent
proton and neutron densities calculated through the HFBTHO code that solves the
nuclear Skyrme-Hartree-Fock-Bogoliubov problem by using the cylindrical
transformed deformed harmonic-oscillator basis. We present and discuss the
values of the volume and surface contributions to the NSE and their ratio
obtained for the Ni, Sn, and Pb isotopic chains around double-magic Ni,
Sn, and Pb nuclei. The results for the -dependence of the
considered quantities are compared with estimations made previously for zero
temperature showing the behavior of the NSE components and their ratio, as well
as with the available experimental data. The sensitivity of the results on
various forms of the density dependence of the symmetry energy is studied. We
confirm the existence of `kinks' of these quantities as functions of the mass
number at MeV for the double closed-shell nuclei Ni and Sn
and the lack of `kinks' for the Pb isotopes, as well as the disappearance of
these kinks as the temperature increases.Comment: 14 pages, 12 figures, 1 table, accepted for publication in Physical
Review
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