539 research outputs found
Density-functional embedding using a plane-wave basis
The constrained electron density method of embedding a Kohn-Sham system in a
substrate system (first described by P. Cortona, Phys. Rev. B {\bf 44}, 8454
(1991) and T.A. Wesolowski and A. Warshel, J. Phys. Chem {\bf 97}, 8050 (1993))
is applied with a plane-wave basis and both local and non-local
pseudopotentials. This method divides the electron density of the system into
substrate and embedded electron densities, the sum of which is the electron
density of the system of interest. Coupling between the substrate and embedded
systems is achieved via approximate kinetic energy functionals. Bulk aluminium
is examined as a test case for which there is a strong interaction between the
substrate and embedded systems. A number of approximations to the
kinetic-energy functional, both semi-local and non-local, are investigated. It
is found that Kohn-Sham results can be well reproduced using a non-local
kinetic energy functional, with the total energy accurate to better than 0.1 eV
per atom and good agreement between the electron densities.Comment: 11 pages, 4 figure
CELL-LINED, NONWOVEN MICROFIBER SCAFFOLDS AS A BLOOD INTERFACE *
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73137/1/j.1749-6632.1977.tb41787.x.pd
Dynamical Generation of Fermion Mass and Magnetic Field in Three-Dimensional QED with Chern-Simons Term
We study dynamical symmetry breaking in three-dimensional QED with a
Chern-Simons (CS) term, considering the screening effect of flavor
fermions. We find a new phase of the vacuum, in which both the fermion mass and
a magnetic field are dynamically generated, when the coefficient of the CS term
equals . The resultant vacuum becomes the finite-density
state half-filled by fermions. For , we find the fermion
remains massless and only the magnetic field is induced. For ,
spontaneous magnetization does not occur and should be regarded as an external
field.Comment: 8 pages, no figure, to be published in Phys. Rev. Let
Assessment of adipokines, adenine nucleotides and uric acid in the dynamics of coronary intervention
Introduction: The association of vaspin
and visfatin, with a myocardial infarction is still
not fully understood. Reduced levels of adenine
nucleotides are hallmarks of chronic heart failure.
There is little data concerning the relationship
between these markers and their changes over time.
Material/Methods: The concentration of adenine
nucleotides, vaspin and visfatinwere assessed in 41
consecutive patients with acute myocardial infarction one
before (day I) and four days after (day IV) percutaneous
coronary intervention (PCI) and a control group.
Results: Visfatin concentrations were higher before and
after PCI vs. control (visfatin I: median 25.55, 20.12 - 30.69
ng/ml; visfatin IV: median 20.79, 16.89 - 25.61 ng/ml vs.
control: median 14.94, 10.66 - 25.25 ng/ml; p < 0.0001).
Vaspin concentrations were lower before and after PCI vs.
control (vaspin I: median 0.18, 0.11 - 0.44 ng/ml; vaspin IV:
median 0.24, 0.15 - 0.58 ng/ml vs. control: median 1.303,
1.13 - 2.26 ng/ml, p < 0.00001). Concentrations of visfatin, day I, correlated well to vaspin concentrations (r2 = 0.201,
p = 0.011). ATP levels were significantly lower in patients
vs. controls (day I: p = 0.00012; day IV: p = 0.0001).
Conclusions: Changes in the analyzed visfatin and vaspin
concentrations can be used as potential MI markers.
Visfatin serum concentration may be considered a
potential marker to differentiate MI over time
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Solubility and Surface Adsorption Characteristics of Metal Oxides to High Temperature
The interaction of high temperature aqueous solutions with mineral surfaces plays a key role in many aspects of fossil, geothermal and nuclear energy production. This is an area of study in which the subsurface geochemical processes that determine brine composition, porosity and permeability changes, reservoir integrity, and fluid flow rates overlap with the industrial processes associated with corrosion of metal parts and deposition of solids in pipes and on heat exchanger surfaces. The sorption of ions on mineral surfaces is also of great interest in both the subsurface and ''above ground'' regimes of power production, playing a key role in subsurface migration of contaminants (nuclear waste disposal, geothermal brine re-injection, etc.) and in plant operations (corrosion mitigation, migration of radioactive metals from reactor core to heat exchanger, etc.). In this paper, results of the solubility and surface chemistry of metal oxides relevant to both regimes are summarized
Myeloid transformation by MLL-ENL depends strictly on C/EBP
Chromosomal rearrangements of the mixed-lineage leukemia gene MLL1 are the hallmark of infant acute leukemia. The granulocyte-macrophage progenitor state forms the epigenetic basis for myelomonocytic leukemia stemness and transformation by MLL-type oncoproteins. Previously, it was shown that the establishment of murine myelomonocytic MLL-ENL transformation, but not its maintenance, depends on the transcription factor C/EBPα, suggesting an epigenetic hit-and-run mechanism of MLL-driven oncogenesis. Here, we demonstrate that compound deletion of Cebpa/Cebpb almost entirely abrogated the growth and survival of MLL-ENL–transformed cells. Rare, slow-growing, and apoptosis-prone MLL-ENL–transformed escapees were recovered from compound Cebpa/Cebpb deletions. The escapees were uniformly characterized by high expression of the resident Cebpe gene, suggesting inferior functional compensation of C/EBPα/C/EBPβ deficiency by C/EBPε. Complementation was augmented by ectopic C/EBPβ expression and downstream activation of IGF1 that enhanced growth. Cebpe gene inactivation was accomplished only in the presence of complementing C/EBPβ, but not in its absence, confirming the Cebpe dependency of the Cebpa/Cebpb double knockouts. Our data show that MLL-transformed myeloid cells are dependent on C/EBPs during the initiation and maintenance of transformation
The Energy Density in the Maxwell-Chern-Simons Theory
A two-dimensional nonrelativistic fermion system coupled to both
electromagnetic gauge fields and Chern-Simons gauge fields is analysed.
Polarization tensors relevant in the quantum Hall effect and anyon
superconductivity are obtained as simple closed integrals and are evaluated
numerically for all momenta and frequencies. The correction to the energy
density is evaluated in the random phase approximation (RPA), by summing an
infinite series of ring diagrams. It is found that the correction has
significant dependence on the particle number density.
In the context of anyon superconductivity, the energy density relative to the
mean field value is minimized at a hole concentration per lattice plaquette
(0.05 \sim 0.06) (p_c a/\hbar)^2 where p_c and a are the momentum cutoff and
lattice constant, respectively. At the minimum the correction is about -5 %
\sim -25 %, depending on the ratio (2m \omega_c)/(p_c^2) where \omega_c is the
frequency cutoff.
In the Jain-Fradkin-Lopez picture of the fractional quantum Hall effect the
RPA correction to the energy density is very large. It diverges logarithmically
as the cutoff is removed, implying that corrections beyond RPA become important
at large momentum and frequency.Comment: 19 pages (plain Tex), 12 figures not included, UMN-TH-1246/9
Higher Derivative CP(N) Model and Quantization of the Induced Chern-Simons Term
We consider higher derivative CP(N) model in 2+1 dimensions with the
Wess-Zumino-Witten term and the topological current density squared term. We
quantize the theory by using the auxiliary gauge field formulation in the path
integral method and prove that the extended model remains renormalizable in the
large N limit. We find that the Maxwell-Chern-Simons theory is dynamically
induced in the large N effective action at a nontrivial UV fixed point. The
quantization of the Chern-Simons term is also discussed.Comment: 8 pages, no figure, a minor change in abstract, added Comments on the
quantization of the Chern-Simons term whose coefficient is also corrected,
and some references are added. Some typos are corrected. Added a new
paragraph checking the equivalence between (3) and (5), and a related
referenc
Mobile Phone Data for Children on the Move: Challenges and Opportunities
Today, 95% of the global population has 2G mobile phone coverage and the
number of individuals who own a mobile phone is at an all time high. Mobile
phones generate rich data on billions of people across different societal
contexts and have in the last decade helped redefine how we do research and
build tools to understand society. As such, mobile phone data has the potential
to revolutionize how we tackle humanitarian problems, such as the many suffered
by refugees all over the world. While promising, mobile phone data and the new
computational approaches bring both opportunities and challenges. Mobile phone
traces contain detailed information regarding people's whereabouts, social
life, and even financial standing. Therefore, developing and adopting
strategies that open data up to the wider humanitarian and international
development community for analysis and research while simultaneously protecting
the privacy of individuals is of paramount importance. Here we outline the
challenging situation of children on the move and actions UNICEF is pushing in
helping displaced children and youth globally, and discuss opportunities where
mobile phone data can be used. We identify three key challenges: data access,
data and algorithmic bias, and operationalization of research, which need to be
addressed if mobile phone data is to be successfully applied in humanitarian
contexts.Comment: 13 pages, book chapte
A cardiac rehabilitation program for breast cancer survivors: A feasibility study
Purpose: The purpose of this study was to determine the feasibility and preliminary efficacy of a cardiac rehabilitation (CR) intervention in the breast cancer population.
Methods: This single-arm feasibility study evaluated a 14-week CR intervention program in breast cancer survivors. Feasibility was defined as completion of at least 30/36 sessions of the program without serious adverse events (SAE) in 80% of patients. Secondary endpoints included the change in VO2 max, cardiovascular disease (CVD) risk factors, Duke Activity Secondary Index (DASI), Brief Fatigue Inventory (BFI), and QLQ-C30. All outcomes were reported as mean change and compared using paired
Results: A total of 25 patients were enrolled in the study. 18 patients of the 25 enrolled (72%) completed the 14 weeks program without SAE. The overall adherence to the study protocol was 60%. Of the 18 participants who did not withdraw from the program, 15 (83%) adhered to the study protocol and completed 30 or more sessions. There was a nonsignificant improvement in VO2 max (mean Δ0.5,
Conclusion: A CR intervention in breast cancer survivors had high adherence in those who were able to complete the 14-week program. The program significantly improved patient reported physical activity, fatigue, and quality of life (QoL), without significant improvement in CVD risk factors. Implications for cancer patients are that early implementation of a CR program should be considered by practitioners as it improves QoL and exercise tolerance in breast cancer survivors
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