5,950 research outputs found
Rayleigh and depinning instabilities of forced liquid ridges on heterogeneous substrates
Depinning of two-dimensional liquid ridges and three-dimensional drops on an
inclined substrate is studied within the lubrication approximation. The
structures are pinned to wetting heterogeneities arising from variations of the
strength of the short-range polar contribution to the disjoining pressure. The
case of a periodic array of hydrophobic stripes transverse to the slope is
studied in detail using a combination of direct numerical simulation and
branch-following techniques. Under appropriate conditions the ridges may either
depin and slide downslope as the slope is increased, or first breakup into
drops via a transverse instability, prior to depinning. The different
transition scenarios are examined together with the stability properties of the
different possible states of the system.Comment: Physics synopsis link:
http://physics.aps.org/synopsis-for/10.1103/PhysRevE.83.01630
Study protocol for a double blind, randomised, placebo-controlled trial of continuous subpectoral local anaesthetic infusion for pain and shoulder function following mastectomy: SUB-pectoral Local anaesthetic Infusion following MastEctomy (SUBLIME) study.
INTRODUCTION: Over 16 000 mastectomies are performed in England and Wales annually. Acute postoperative pain and nausea are common. The most frequently occurring long-term complications are chronic pain (up to 50%) and reduced shoulder function (reported at 35%). Regional techniques that improve acute postoperative pain relief may reduce the incidence of these complications. This study assesses the effectiveness of a 24-hour continuous local anaesthetic in the subpectoral plane in improving postoperative pain and quality of life in patients undergoing mastectomy. METHODS AND ANALYSIS: This is a randomised, double blind, placebo-controlled, two-centre, parallel group trial in women undergoing mastectomy with or without axillary involvement. One hundred and sixty participants will be randomised in a 1:1 ratio to receive either 0.25% levobupivacaine or 0.9% saline by subpectoral infusion postoperatively for 24 h. All participants will be provided with an intravenous morphine patient-controlled analgesia (PCA) system. Participants will be followed-up for 24 h in hospital and at approximately 14 days and 6 months postoperatively. Joint primary outcome measures are total morphine consumption and total pain score (captured via patient-recorded visual analogue scale (VAS) 4 hourly) during the first 24 h postoperatively. Primary statistical analysis of total pain is based on the area under the curve of pain versus time graph. Secondary outcomes include PCA attempts in first 24 h; VAS pain scores and shoulder function by goniometry at 24 h, 14 days (approximately) and 6 months; Verbal Rating Scale pain scores in first 24 h; Brief Pain Inventory and Oxford Shoulder Score at 6 months; duration of hospital stay; incidence of postoperative nausea and vomiting; cost-effectiveness. ETHICS AND DISSEMINATION: The study is approved by the South West England Research Ethics Committee (12/SW/0149). RESULTS: will be published in a peer-reviewed journal and presented at local, national and international scientific meetings. TRIAL REGISTRATION: ISRCTN46621916. EudraCT 2011-005775-16
Simple scheme for expanding a polarization-entangled W state by adding one photon
We propose a simple scheme for expanding a polarization-entangled W state. By
mixing a single photon and one of the photons in an n-photon W state at a
polarization-dependent beam splitter (PDBS), we can obtain an (n+1)-photon W
state after post-selection. Our scheme also opens the door for generating
n-photon W states using single photons and linear optics.Comment: 3 pages, 2 figure
Macro- and micro-strain in GaN nanowires on Si(111)
We analyze the strain state of GaN nanowire ensembles by x-ray diffraction.
The nanowires are grown by molecular beam epitaxy on a Si(111) substrate in a
self-organized manner. On a macroscopic scale, the nanowires are found to be
free of strain. However, coalescence of the nanowires results in micro-strain
with a magnitude from +-0.015% to +-0.03%.This micro-strain contributes to the
linewidth observed in low-temperature photoluminescence spectra
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Association Between High Perceived Stress Over Time and Incident Hypertension in Black Adults: Findings From the Jackson Heart Study.
Background Chronic psychological stress has been associated with hypertension, but few studies have examined this relationship in blacks. We examined the association between perceived stress levels assessed annually for up to 13 years and incident hypertension in the Jackson Heart Study, a community-based cohort of blacks. Methods and Results Analyses included 1829 participants without hypertension at baseline (Exam 1, 2000-2004). Incident hypertension was defined as blood pressure≥140/90 mm Hg or antihypertensive medication use at Exam 2 (2005-2008) or Exam 3 (2009-2012). Each follow-up interval at risk of hypertension was categorized as low, moderate, or high perceived stress based on the number of annual assessments between exams in which participants reported "a lot" or "extreme" stress over the previous year (low, 0 high stress ratings; moderate, 1 high stress rating; high, ≥2 high stress ratings). During follow-up (median, 7.0 years), hypertension incidence was 48.5%. Hypertension developed in 30.6% of intervals with low perceived stress, 34.6% of intervals with moderate perceived stress, and 38.2% of intervals with high perceived stress. Age-, sex-, and time-adjusted risk ratios (95% CI) associated with moderate and high perceived stress versus low perceived stress were 1.19 (1.04-1.37) and 1.37 (1.20-1.57), respectively (P trend<0.001). The association was present after adjustment for demographic, clinical, and behavioral factors and baseline stress (P trend=0.001). Conclusions In a community-based cohort of blacks, higher perceived stress over time was associated with an increased risk of developing hypertension. Evaluating stress levels over time and intervening when high perceived stress is persistent may reduce hypertension risk
University of Minnesota – Twin Cities Modifications to the Montana State University Telemetry System for Stratospheric Eclipse Ballooning
On August 21, 2017, the path of totality of a solar eclipse swept across the continental United States from Oregon to South Carolina. Our team, flying weather balloons near Grand Island, Nebraska, was able to live stream the shadow of the moon from the stratosphere to the ground. The team was able to track our balloons with high accuracy due to new payload software and hardware implemented on the still image telemetry platform developed by the Montana Space Grant. In addition, the modified system allowed the team to relay commands and receive information from individual payloads attached to our balloons, giving live telemetry and control from a new GUI-based ground station control application. Although the eclipse is now over, the system will still be a powerful and useful tool for the University of Minnesota stratospheric ballooning team. The platform could be used for any other application needing real-time, ground-based communication to various payloads on a balloon gondola
Quantum teleportation and entanglement swapping with linear optics logic gates
We report on the usage of a linear optics phase gate for distinguishing all
four Bell states simultaneously in a quantum teleportation and entanglement
swapping protocol. This is demonstrated by full state tomography of the one and
two qubit output states of the two protocols, yielding average state fidelities
of about 0.83 and 0.77, respectively. In addition, the performance of the
teleportation channel is characterised by quantum process tomography. The non
classical properties of the entanglement swapping output states are further
confirmed by the violation of a CHSH-type Bell inequality of 2.14 on average.Comment: 11 pages, 3 figure
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