219 research outputs found
Focussing quantum states
Does the size of atoms present a lower limit to the size of electronic
structures that can be fabricated in solids? This limit can be overcome by
using devices that exploit quantum mechanical scattering of electron waves at
atoms arranged in focussing geometries on selected surfaces. Calculations
reveal that features smaller than a hydrogen atom can be obtained. These
structures are potentially useful for device applications and offer a route to
the fabrication of ultrafine and well defined tips for scanning tunneling
microscopy.Comment: 4 pages, 4 figure
Direct extraction of the Eliashberg function for electron-phonon coupling: A case study of Be(1010)
We propose a systematic procedure to directly extract the Eliashberg function
for electron-phonon coupling from high-resolution angle-resolved photoemission
data. The procedure is successfully applied to the Be(1010) surface, providing
new insights to electron-phonon coupling at this surface. The method is shown
to be robust against imperfections in experimental data and suitable for wider
applications.Comment: 4 pages, 4 figures. More details concerning the procedure are
include
Titanium and nitrogen interactions under laser additive manufacturing conditions
To understand how to make bulk titanium parts or coatings with desired levels of titanium nitrides, this paper investigates the dynamic interactions between titanium and nitrogen under representative laser-based additive manufacturing (AM) conditions. Under a set of gas environments containing different concentrations of nitrogen, the titanium and nitrogen reaction products—formed under typical Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) AM scanning conditions—are examined for compositions, phases, and microstructures. In-situ synchrotron X-ray diffraction (SXRD) test is performed to reveal the high temperature reaction steps between titanium and nitrogen
Real Space Observations of Magnesium Hydride Formation and Decomposition
The mechanisms of magnesium hydride formation and thermal decomposition are
directly examined using in-situ imaging.Comment: 3 pages, 4 figure
Development of the ATAQ-IPF: a tool to assess quality of life in IPF
<p>Abstract</p> <p>Background</p> <p>There is no disease-specific instrument to assess health-related quality of life (HRQL) in patients with idiopathic pulmonary fibrosis (IPF).</p> <p>Methods</p> <p>Patients' perspectives were collected to develop domains and items for an IPF-specific HRQL instrument. We used item variance and Rasch analysis to construct the ATAQ-IPF (A Tool to Assess Quality of life in IPF).</p> <p>Results</p> <p>The ATAQ-IPF version 1 is composed of 74 items comprising 13 domains. All items fit the Rasch model. Domains and the total instrument possess acceptable psychometric characteristics for a multidimensional questionnaire. The pattern of correlations between ATAQ-IPF scores and physiologic variables known to be important in IPF, along with significant differences in ATAQ-IPF scores between subjects using versus those not using supplemental oxygen, support its validity.</p> <p>Conclusions</p> <p>Patient-centered and careful statistical methodologies were used to construct the ATAQ-IPF version 1, an IPF-specific HRQL instrument. Simple summation scoring is used to derive individual domain scores as well as a total score. Results support the validity of the ATAQ-IPF, and future studies will build on that validity.</p
Linear Free Energy Relationship Correlations for Enthalpies of Solvation of Organic Solutes into Room-Temperature Ionic Liquids Based on the Abraham Model with Ion-Specific Equation Coefficients
Scanning tunneling microscopy and spectroscopy at low temperatures of the (110) surface of Te doped GaAs single crystals
We have performed voltage dependent imaging and spatially resolved
spectroscopy on the (110) surface of Te doped GaAs single crystals with a low
temperature scanning tunneling microscope (STM). A large fraction of the
observed defects are identified as Te dopant atoms which can be observed down
to the fifth subsurface layer. For negative sample voltages, the dopant atoms
are surrounded by Friedel charge density oscillations. Spatially resolved
spectroscopy above the dopant atoms and above defect free areas of the GaAs
(110) surface reveals the presence of conductance peaks inside the
semiconductor band gap. The appearance of the peaks can be linked to charges
residing on states which are localized within the tunnel junction area. We show
that these localized states can be present on the doped GaAs surface as well as
at the STM tip apex.Comment: 8 pages, 8 figures, accepted for publication in PR
A pilot randomized clinical trial of intermittent occlusion therapy liquid crystal glasses versus traditional patching for treatment of moderate unilateral amblyopia
PURPOSE:
To compare the effectiveness of intermittent occlusion therapy (IO therapy) using liquid crystal glasses and continuous occlusion therapy using traditional adhesive patches for treating amblyopia.
METHODS:
Children 3-8 years of age with previously untreated, moderate, unilateral amblyopia (visual acuity of 20/40 to 20/100 in the amblyopic eye) were enrolled in this randomized controlled trial. Amblyopia was associated with strabismus, anisometropia, or both. All subjects had worn any optimal refractive correction for at least 12 weeks without improvement. Subjects were randomized into two treatment groups: a 4-hour IO therapy group with liquid crystal glasses (Amblyz), set at 30-second opaque/transparent intervals (occluded 50% of wear time), and a 2-hour continuous patching group (occluded 100% of wear time). For each patient, visual acuity was measured using ATS-HOTV before and after 12 weeks of treatment.
RESULTS:
Data from 34 patients were available for analysis. Amblyopic eye visual acuity improvement from baseline was 0.15 ± 0.12 logMAR (95% CI, 0.09-0.15) in the IO therapy group (n = 19) and 0.15 ± 0.11 logMAR (95% CI, 0.1-0.15) in the patching group (n = 15). In both groups improvement was significant, but the difference between groups was not (P = 0.73). No adverse effects were reported.
CONCLUSIONS:
In this pilot study, IO therapy with liquid crystal glasses is not inferior to adhesive patching and is a promising alternative treatment for children 3-8 years of age with moderate amblyopia
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