305 research outputs found
Changes in hospitals' credentialing requirements for board certification from 2005 to 2010
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98213/1/jhm2033.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/98213/2/jhm23033-sup-0001-suppinfo.pd
Low-Temperature Orientation Dependence of Step Stiffness on {111} Surfaces
For hexagonal nets, descriptive of {111} fcc surfaces, we derive from
combinatoric arguments a simple, low-temperature formula for the orientation
dependence of the surface step line tension and stiffness, as well as the
leading correction, based on the Ising model with nearest-neighbor (NN)
interactions. Our formula agrees well with experimental data for both Ag and
Cu{111} surfaces, indicating that NN-interactions alone can account for the
data in these cases (in contrast to results for Cu{001}). Experimentally
significant corollaries of the low-temperature derivation show that the step
line tension cannot be extracted from the stiffness and that with plausible
assumptions the low-temperature stiffness should have 6-fold symmetry, in
contrast to the 3-fold symmetry of the crystal shape. We examine Zia's exact
implicit solution in detail, using numerical methods for general orientations
and deriving many analytic results including explicit solutions in the two
high-symmetry directions. From these exact results we rederive our simple
result and explore subtle behavior near close-packed directions. To account for
the 3-fold symmetry in a lattice gas model, we invoke a novel
orientation-dependent trio interaction and examine its consequences.Comment: 11 pages, 8 figure
Hospital discharges for fever and neutropenia in pediatric cancer patients: United States, 2009
Background
Fever and neutropenia (FN) is a common complication of pediatric cancer treatment, but hospital utilization patterns for this condition are not well described.
Methods
Data were analyzed from the Kids’ Inpatient Database (KID), an all-payer US hospital database, for 2009. Pediatric FN patients were identified using: age ≤19 years, urgent or emergent admit type, non-transferred, and a combination of ICD-9-CM codes for fever and neutropenia. Sampling weights were used to permit national inferences.
Results
Pediatric cancer patients accounted for 1.5 % of pediatric hospital discharges in 2009 (n = 110,967), with 10.1 % of cancer-related discharges meeting FN criteria (n = 11,261). Two-fifths of FN discharges had a “short length of stay” (SLOS) of ≤3 days, which accounted for approximately $65.5 million in hospital charges. Upper respiratory infection (6.0 %) and acute otitis media (AOM) (3.7 %) were the most common infections associated with SLOS. Factors significantly associated with SLOS included living in the Midwest region (OR = 1.65, 1.22–2.24) or West region (OR 1.54, 1.11–2.14) versus Northeast, having a diagnosis of AOM (OR = 1.39, 1.03–1.87) or viral infection (OR = 1.63, 1.18–2.25) versus those without those comorbidities, and having a soft tissue sarcoma (OR = 1.47, 1.05–2.04), Hodgkin lymphoma (OR = 2.33, 1.62–3.35), or an ovarian/testicular tumor (OR = 1.76, 1.05–2.95) compared with patients without these diagnoses.
Conclusion
FN represents a common precipitant for hospitalizations among pediatric cancer patients. SLOS admissions are rarely associated with serious infections, but contribute substantially to the burden of hospitalization for pediatric FN
Isovector part of nuclear energy density functional from chiral two- and three-nucleon forces
A recent calculation of the nuclear energy density functional from chiral
two- and three-nucleon forces is extended to the isovector terms pertaining to
different proton and neutron densities. An improved density-matrix expansion is
adapted to the situation of small isospin-asymmetries and used to calculate in
the Hartree-Fock approximation the density-dependent strength functions
associated with the isovector terms. The two-body interaction comprises of
long-range multi-pion exchange contributions and a set of contact terms
contributing up to fourth power in momenta. In addition, the leading order
chiral three-nucleon interaction is employed with its parameters fixed in
computations of nuclear few-body systems. With this input one finds for the
asymmetry energy of nuclear matter the value MeV,
compatible with existing semi-empirical determinations. The strength functions
of the isovector surface and spin-orbit coupling terms come out much smaller
than those of the analogous isoscalar coupling terms and in the relevant
density range one finds agreement with phenomenological Skyrme forces. The
specific isospin- and density-dependences arising from the chiral two- and
three-nucleon interactions can be explored and tested in neutron-rich systems.Comment: 14 pages, 7 figures, to be published in European Physical Journal
Fluctuations, line tensions, and correlation times of nanoscale islands on surfaces
We analyze in detail the fluctuations and correlations of the (spatial)
Fourier modes of nano-scale single-layer islands on (111) fcc crystal surfaces.
We analytically show that the Fourier modes of the fluctuations couple due to
the anisotropy of the crystal, changing the power spectrum of the fluctuations,
and that the actual eigenmodes of the fluctuations are the appropriate linear
combinations of the Fourier modes. Using kinetic Monte Carlo simulations with
bond-counting parameters that best match realistic energy barriers for hopping
rates, we deduce absolute line tensions as a function of azimuthal orientation
from the analyses of the fluctuation of each individual mode. The
autocorrelation functions of these modes give the scaling of the correlation
times with wavelength, providing us with the rate-limiting kinetics driving the
fluctuations, here step-edge diffusion. The results for the energetic
parameters are in reasonable agreement with available experimental data for
Pb(111) surfaces, and we compare the correlation times of island-edge
fluctuations to relaxation times of quenched Pb crystallites.Comment: 11 pages, 8 figures; to appear in PRB 70, xxx (15 Dec 2004), changes
in MC and its implication
Nuclear energy density functional from chiral two- and three-nucleon interactions
An improved density-matrix expansion is used to calculate the nuclear energy
density functional from chiral two- and three-nucleon interactions. The
two-body interaction comprises long-range one- and two-pion exchange
contributions and a set of contact terms contributing up to fourth power in
momenta. In addition we employ the leading order chiral three-nucleon
interaction with its parameters and fixed in
calculations of nuclear few-body systems. With this input the nuclear energy
density functional is derived to first order in the two- and three-nucleon
interaction. We find that the strength functions and
of the surface and spin-orbit terms compare in the relevant
density range reasonably with results of phenomenological Skyrme forces.
However, an improved description requires (at least) the treatment of the
two-body interaction to second order. This observation is in line with the
deficiencies in the nuclear matter equation of state that remain
in the Hartree-Fock approximation with low-momentum two- and three-nucleon
interactions.Comment: 16 pages, 12 figures, submitted to Eur. Phys. J.
Instabilities in the Nuclear Energy Density Functional
In the field of Energy Density Functionals (EDF) used in nuclear structure
and dynamics, one of the unsolved issues is the stability of the functional.
Numerical issues aside, some EDFs are unstable with respect to particular
perturbations of the nuclear ground-state density. The aim of this contribution
is to raise questions about the origin and nature of these instabilities, the
techniques used to diagnose and prevent them, and the domain of density
functions in which one should expect a nuclear EDF to be stable.Comment: Special issue "Open Problems in Nuclear Structure Theory" of
Jour.Phys.G - accepted. 7 pages, 2 figure
Research priorities of people living with Turner syndrome
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148393/1/ajmgc31676.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148393/2/ajmgc31676_am.pd
Validation of EpiTRAQ, a transition readiness assessment tool for adolescents and young adults with epilepsy
ObjectiveTo design and validate a transition readiness assessment tool for adolescents and young adults with epilepsy and without intellectual disability.MethodsWe adapted a general transition readiness assessment tool (TRAQ) to add epilepsy‐relevant items based on concepts in current epilepsy quality measures. The adapted tool, EpiTRAQ, maintained the original structure and scoring system. Concurrent with clinical implementation in pediatric and adult epilepsy clinics at an academic medical center, we assessed the validity and reliability of this adapted tool for patients 16‐26 years of age. This process included initial validation with 302 patients who completed EpiTRAQ between October 2017 and May 2018; repeat validation with 381 patients who completed EpiTRAQ between June 2018 and September 2019; and retest reliability among 153 patients with more than one completed EpiTRAQ.ResultsMean scores were comparable between initial and repeat validation populations (absolute value differences between 0.05 and 0.1); internal consistency ranged from good to high. For both the initial and repeat validation, mean scores and internal consistency demonstrated high comparability to the original TRAQ validation results. Upon retest, few patients rated themselves with a lower score, while the majority rated themselves with higher scores.SignificanceEpiTRAQ is a valid and reliable tool for assessing transition readiness in adolescents and young adults with epilepsy and without intellectual disability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162789/2/epi412427_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162789/1/epi412427.pd
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