Optical Quantum Computation with Perpetually Coupled Spins

The possibility of using strongly and continuously interacting spins for quantum computation has recently been discussed. Here we present a simple optical scheme that achieves this goal while avoiding the drawbacks of earlier proposals. We employ a third state, accessed by a classical laser field, to create an effective barrier to information transfer. The mechanism proves to be highly efficient both for continuous and pulsed laser modes; moreover it is very robust, tolerating high decay rates for the excited states. The approach is applicable to a broad range of systems, in particular dense structures such as solid state self-assembled (e.g., molecular) devices. Importantly, there are existing structures upon which `first step' experiments could be immediately performed.Comment: 5 pages including 3 figures. Updated to published versio

Intestinal Angioedema Misdiagnosed as Recurrent Episodes of Gastroenteritis

Emergency physicians (EP) frequently encounter angioedema involving the lips and tongue. However, angioedema from Angiotensin Converting Enzyme inhibitors or hereditary angioedema (HAE) can present with gastrointestinal symptoms due to bowel wall involvement. EPs should begin to consider this clinical entity as a potential cause for abdominal pain and associated gastrointestinal symptoms given the common use of medications that can precipitate angioedema. We report a case of a 34-year-old woman who presented with abdominal cramping, vomiting and diarrhea due to an acute exacerbation of HAE

Vascular Pedicle Width on Chest Radiograph as a Measure of Volume Overload: Meta-Analysis

Introduction: Vascular pedicle width (VPW), a measurement obtained from a chest radiograph (CR), is thought to be an indicator of circulating blood volume. To date there are only a handful of studies that demonstrate a correlation between high VPW and volume overload, each utilizing different VPW values and CR techniques. Our objective was to determine a mean VPW measurement from erect and supine CRs and to determine whether VPW correlates with volume overload.Methods: MEDLINE database, Web of Science, and the Cochrane Central Register of Controlled Trials were searched electronically for relevant articles. References from the original and review publications selected electronically were manually searched for additional relevant articles. Two investigators independently reviewed relevant articles for inclusion criteria and data extraction. MeanVPW measurements from both supine and erect CRs and their correlation with volume overload were calculated.Results: Data from 8 studies with a total of 363 subjects were included, resulting in mean VPWmeasurements of 71 mm (95% confidence interval [CI] 64.9–77.3) and 62 mm (95% CI 49.3–75.1) for supine and erect CRs, respectively. The correlation coefficients for volume overload and VPW were 0.81 (95% CI 0.74–0.86) for both CR techniques and 0.81 (95% CI 0.72–0.87) for supine CR and 0.80 (95% CI 0.69–0.87) for erect CR, respectively.Conclusion: There is a clinical and statistical correlation between VPW and volume overload. VPW may be used to evaluate the volume status of a patient regardless of the CR technique used. [West J Emerg Med. 2011;12(4):426–432.

Improved Phase Locking of Laser Arrays with Nonlinear Coupling

An arrangement based on a degenerate cavity laser for forming an array of nonlinearly coupled lasers with an intracavity saturable absorber is presented. More than 30 lasers were spatially phase locked and temporally Q switched. The arrangement with nonlinear coupling was found to be 25 times more sensitive to loss differences and converged five times faster to the lowest loss phase locked state than with linear coupling, thus providing a unique solution to problems that have several near-degenerate solutions

RACE-IT - Rapid Acute Coronary Syndrome Exclusion using the Beckman Coulter Access high-sensitivity cardiac troponin I: A stepped-wedge cluster randomized trial

Background: Protocols utilizing high-sensitivity cardiac troponin (hs-cTn) assays for the evaluation of suspected acute coronary syndrome (ACS) in the emergency department (ED) have been gaining popularity across the US and the world. These protocols more rapidly rule-out ACS and more accurately identify the presence of acute myocardial injury. At this time, few randomized trials have evaluated the safety and operational impact of these assays, resulting in limited evidence to guide the use and implementation of hs-cTn in the ED. Objective: The main study objective is to test the effectiveness of a rapid ACS rule-out pathway using hs-cTnI in safely discharging patients from the ED for whom clinical suspicion for ACS exists. Design: This prospective, implementation trial (n = 11,070) will utilize a stepped wedge cluster randomized trial design. The design will allow for all participating sites to capture benefit from the implementation of the hs-cTnI pathway while providing data evaluating the effectiveness in providing safe and rapid evaluation of patients with clinical suspicion for ACS. Summary: Demonstrating that clinical pathways using hs-cTnI can be effectively implemented to rapidly rule-out ACS while conserving costly hospital resources has significant implications for the care of patients with possible acute cardiac conditions in EDs across the US. Clinicaltrialsgov identifier: NCT04488913