2,178 research outputs found
Dominance of interface chemistry over the bulk properties in determining the electronic structure of epitaxial metal/perovskite oxide heterojunctions
This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this record.We show that despite very similar crystallographic properties and work function values in bulk Fe and Cr, epitaxial films of these metals on Nb:SrTiO3(001) exhibit completely different heterojunction electronic properties. The Cr/SrTiO3 interface is ohmic, whereas Fe/SrTiO3 forms a Schottky barrier with a barrier height of 0.50 eV. This difference arises because of variations in interface chemistry. In contrast to Cr [Chambers, S. A., Adv. Mater. 2013, 25, 4001.], in-diffused Fe exhibits a +2 oxidation state and occupies Ti sites in the perovskite lattice, resulting in negligible charge transfer to Ti, upward band bending, and Schottky barrier formation. The differences between Cr and Fe are understood by performing first-principles calculations of the energetics of defect formation, which corroborate experimental results.This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award #10122. The work described was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at PNNL. PNNL is operated by Battelle for the DOE under Contract DE-AC05-76RLO1830. S.P.H. was supported by the EPSRC Grant No.EP/I009973/1. Access to the HECToR high-performance computing facility was made available via S.P.H. membership of the U.K.’s HPC Materials Chemistry Consortium, which was funded by EPSRC (EP/F067496)
Meta-analysis of scalp acupuncture for acute hypertensive intracerebral hemorrhage
Objectives: Scalp acupuncture (SA) is a commonly used therapeutic approach for primary intracerebral hemorrhage (ICH) in Traditional Chinese Medicine (TCM), but the efficacy and safety of SA therapy are still undetermined. The aim of this study is to systematically evaluate the efficacy and safety of SA therapy for the treatment of acute hypertensive ICH. Methods: Literature reports with randomized controlled clinical trials and controlled clinical trials on SA therapy for acute hypertensive ICH were searched, and the efficacy and safety of SA therapy were evaluated by using the Cochrane systematic review methods. The primary outcome measures were death or dependency at the end of long-term follow-up (at least 3 months) and adverse events. The secondary outcome measure was neurological deficit improvement at the end of the treatment course. Results: Seven (7) independent trials (230 patients) were included in this study. All trials described the methods of randomization in which four trials had adequate concealment of randomization at the level of grade A, but no trial included sham acupuncture as a control group. None of the trials included "death or dependency" as a primary outcome measure. Four (4) trials contained safety assessments and stated that no adverse event was found, whereas the other three trials did not provide the information about adverse events. By using random effects statistical model, it was found that patients with acute hypertensive ICH who received SA therapy had significantly improved neurological deficit scores (Z=4.97, p<0.01). Conclusions: Although SA therapy is widely used to treat acute hypertensive ICH in TCM, the efficacy and safety of SA therapy remain to be further determined. No evidence is available on whether SA therapy can be used to treat acute ICH according to the primary outcome measure. However, SA therapy appears to be able to improve neurological deficit in patients with acute hypertensive ICH. © 2011, Mary Ann Liebert, Inc.published_or_final_versio
Asymmetric Origin for Gravitino Relic Density in the Hybrid Gravity-Gauge Mediated Supersymmetry Breaking
We propose the hybrid gravity-gauge mediated supersymmetry breaking where the
gravitino mass is about several GeV. The strong constraints on supersymmetry
viable parameter space from the CMS and ATLAS experiments at the LHC can be
relaxed due to the heavy colored supersymmetric particles, and it is consistent
with null results in the dark matter (DM) direct search experiments such as
XENON100. In particular, the possible maximal flavor and CP violations from the
relatively small gravity mediation may naturally account for the recent LHCb
anomaly. In addition, because the gravitino mass is around the asymmetric DM
mass, we propose the asymmetric origin of the gravitino relic density and solve
the cosmological coincident problem on the DM and baryon densities \Omega_{\rm
DM}:\Omega_{B}\approx 5:1. The gravitino relic density arises from asymmetric
metastable particle (AMP) late decay. However, we show that there is no AMP
candidate in the minimal supersymmetric Standard Model (SM) due to the robust
gaugino/Higgsino mediated wash-out effects. Interestingly, AMP can be realized
in the well motivated supersymmetric SMs with vector-like particles or
continuous U(1)_R symmetry. Especially, the lightest CP-even Higgs boson mass
can be lifted in the supersymmetric SMs with vector-like particles.Comment: RevTex4, 21 pages, 1 figure, minor corrections, JHEP versio
What has finite element analysis taught us about diabetic foot disease and its management?:a systematic review
Over the past two decades finite element (FE) analysis has become a popular tool for researchers seeking to simulate the biomechanics of the healthy and diabetic foot. The primary aims of these simulations have been to improve our understanding of the foot's complicated mechanical loading in health and disease and to inform interventions designed to prevent plantar ulceration, a major complication of diabetes. This article provides a systematic review and summary of the findings from FE analysis-based computational simulations of the diabetic foot.A systematic literature search was carried out and 31 relevant articles were identified covering three primary themes: methodological aspects relevant to modelling the diabetic foot; investigations of the pathomechanics of the diabetic foot; and simulation-based design of interventions to reduce ulceration risk.Methodological studies illustrated appropriate use of FE analysis for simulation of foot mechanics, incorporating nonlinear tissue mechanics, contact and rigid body movements. FE studies of pathomechanics have provided estimates of internal soft tissue stresses, and suggest that such stresses may often be considerably larger than those measured at the plantar surface and are proportionally greater in the diabetic foot compared to controls. FE analysis allowed evaluation of insole performance and development of new insole designs, footwear and corrective surgery to effectively provide intervention strategies. The technique also presents the opportunity to simulate the effect of changes associated with the diabetic foot on non-mechanical factors such as blood supply to local tissues.While significant advancement in diabetic foot research has been made possible by the use of FE analysis, translational utility of this powerful tool for routine clinical care at the patient level requires adoption of cost-effective (both in terms of labour and computation) and reliable approaches with clear clinical validity for decision making
Multiphase modelling of tumour growth and extracellular matrix interaction: mathematical tools and applications
Resorting to a multiphase modelling framework, tumours are described here as a mixture of tumour and host cells within a porous structure constituted by a remodelling extracellular matrix (ECM), which is wet by a physiological extracellular fluid. The model presented in this article focuses mainly on the description of mechanical interactions of the growing tumour with the host tissue, their influence on tumour growth, and the attachment/detachment mechanisms between cells and ECM. Starting from some recent experimental evidences, we propose to describe the interaction forces involving the extracellular matrix via some concepts coming from viscoplasticity. We then apply the model to the description of the growth of tumour cords and the formation of fibrosis
Resonances in and
A partial wave analysis is presented of and
from a sample of 58M events in the BES II detector. The
is observed clearly in both sets of data, and parameters of the
Flatt\' e formula are determined accurately: (stat)
(syst) MeV/c, MeV/c, . The data also exhibit a strong peak
centred at MeV/c. It may be fitted with and a
dominant signal made from interfering with a smaller
component. There is evidence that the signal is
resonant, from interference with . There is also a state in with MeV/c and
MeV/c; spin 0 is preferred over spin 2. This state, , is
distinct from . The data contain a strong peak due to
. A shoulder on its upper side may be fitted by interference
between and .Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.
Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0
Using 58 million J/psi and 14 million psi' decays obtained by the BESII
experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The
result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous
measurements.Comment: 9 pages, 8 figures, RevTex
Search for K_S K_L in psi'' decays
K_S K_L from psi'' decays is searched for using the psi'' data collected by
BESII at BEPC, the upper limit of the branching fraction is determined to be
B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is
compared with the prediction of the S- and D-wave mixing model of the
charmonia, based on the measurements of the branching fractions of J/psi-->K_S
K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur
First observation of psi(2S)-->K_S K_L
The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data
collected with the Beijing Spectrometer (BESII) at the Beijing Electron
Positron Collider (BEPC); the branching ratio is determined to be
B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with
J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the
prediction of the perturbative QCD ``12%'' rule. The result, together with the
branching ratios of psi(2S) decays to other pseudoscalar meson pairs
(\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the
three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let
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