726 research outputs found
Fast Excitation and Photon Emission of a Single-Atom-Cavity System
We report on the fast excitation of a single atom coupled to an optical
cavity using laser pulses that are much shorter than all other relevant
processes. The cavity frequency constitutes a control parameter that allows the
creation of single photons in a superposition of two tunable frequencies. Each
photon emitted from the cavity thus exhibits a pronounced amplitude modulation
determined by the oscillatory energy exchange between the atom and the cavity.
Our technique constitutes a versatile tool for future quantum networking
experiments.Comment: 4 pages, 5 figure
A successfully thrombolysed acute inferior myocardial infarction due to type A aortic dissection with lethal consequences: the importance of early cardiac echocardiography
Thrombolysis, a standard therapy for ST elevation myocardial infarction (STEMI) in non-PCI-capable hospitals, may be catastrophic for patients with aortic dissection leading to further expansion, rupture and uncontrolled bleeding. Stanford type A aortic dissection, rarely may mimic myocardial infarction. We report a case of a patient with an inferior STEMI thrombolysed with tenecteplase and followed by clinical and electrocardiographic evidence of successful reperfusion, which was found later to be a lethal acute aortic dissection. Prognostic implications of early diagnosis applying transthoracic echocardiography (TTE) are described
Secondhand Smoke Exposure and Coronary Artery Calcification among Nonsmoking Participants of a Population-Based Cohort
Background: Secondhand smoke (SHS) consists of fine particulate matter, carcinogens, and various toxins that affect large parts of the population. SHS increases the risk for acute cardiovascular events and may contribute to the development of atherosclerosis
Intracoronary Brachytherapy, a Promising Treatment Option for Diabetic Patients: Results from a European Multicenter Registry (RENO)
Despite advances in the interventional treatment of coronary disease, diabetics still have double the case fatality rate as nondiabetics. The purpose of this an
AMS INSIGHT—Absorbable Metal Stent Implantation for Treatment of Below-the-Knee Critical Limb Ischemia: 6-Month Analysis
Endoluminal treatment of infrapopliteal artery lesions is a matter of controversy. Bioabsorbable stents are discussed as a means to combine mechanical prevention of vessel recoil with the advantages of long-term perspectives. The possibility of not having a permanent metallic implant could permit the occurrence of positive remodeling with lumen enlargement to compensate for the development of new lesions. The present study was designed to investigate the safety of absorbable metal stents (AMSs) in the infrapopliteal arteries based on 1- and 6-month clinical follow-up and efficacy based on 6-month angiographic patency. One hundred seventeen patients with 149 lesions with chronic limb ischemia (CLI) were randomized to implantation of an AMS (60 patients, 74 lesions) or stand-alone percutaneous transluminal angioplasty (PTA; 57 patients, 75 lesions). Seven PTA-group patients “crossed over” to AMS stenting. The study population consisted of patients with symptomatic CLI (Rutherford categories 4 and 5) and de novo stenotic (>50%) or occlusive atherosclerotic disease of the infrapopliteal arteries who presented with a reference diameter of between 3.0 and 3.5 mm and a lesion length of <15 mm. The primary safety endpoint was defined as absence of major amputation and/or death within 30 days after index intervention and the primary efficacy endpoint was the 6-month angiographic patency rate as confirmed by core-lab quantitative vessel analysis. The 30-day complication rate was 5.3% (3/57) and 5.0% (3/60) in patients randomized for PTA alone and PTA followed by AMS implantation, respectively. On an intention-to-treat basis, the 6-month angiographic patency rate for lesions treated with AMS (31.8%) was significantly lower (p = 0.013) than the rate for those treated with PTA (58.0%). Although the present study indicates that the AMS technology can be safely applied, it did not demonstrate efficacy in long-term patency over standard PTA in the infrapopliteal vessels
Comparative analysis of homology models of the Ah receptor ligand binding domain: Verification of structure-function predictions by site-directed mutagenesis of a nonfunctional receptor
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that mediates the biological and toxic effects of a wide variety of structurally diverse chemicals, including the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While significant interspecies differences in AHR ligand binding specificity, selectivity, and response have been observed, the structural determinants responsible for those differences have not been determined, and homology models of the AHR ligand-binding domain (LBD) are available for only a few species. Here we describe the development and comparative analysis of homology models of the LBD of 16 AHRs from 12 mammalian and nonmammalian species and identify the specific residues contained within their ligand binding cavities. The ligand-binding cavity of the fish AHR exhibits differences from those of mammalian and avian AHRs, suggesting a slightly different TCDD binding mode. Comparison of the internal cavity in the LBD model of zebrafish (zf) AHR2, which binds TCDD with high affinity, to that of zfAHR1a, which does not bind TCDD, revealed that the latter has a dramatically shortened binding cavity due to the side chains of three residues (Tyr296, Thr386, and His388) that reduce the amount of internal space available to TCDD. Mutagenesis of two of these residues in zfAHR1a to those present in zfAHR2 (Y296H and T386A) restored the ability of zfAHR1a to bind TCDD and to exhibit TCDD-dependent binding to DNA. These results demonstrate the importance of these two amino acids and highlight the predictive potential of comparative analysis of homology models from diverse species. The availability of these AHR LBD homology models will facilitate in-depth comparative studies of AHR ligand binding and ligand-dependent AHR activation and provide a novel avenue for examining species-specific differences in AHR responsiveness. © 2013 American Chemical Society
New insights regarding the incidence, presentation and treatment options of aorto-oesophageal fistulation after thoracic endovascular aortic repair: the European Registry of Endovascular Aortic Repair Complications
OBJECTIVES:
To review the incidence, clinical presentation, definite management and 1-year outcome in patients with aorto-oesophageal fistulation (AOF) following thoracic endovascular aortic repair (TEVAR).
METHODS:
International multicentre registry (European Registry of Endovascular Aortic Repair Complications) between 2001 and 2011 with a total caseload of 2387 TEVAR procedures (17 centres).
RESULTS:
Thirty-six patients with a median age of 69 years (IQR 56-75), 25% females and 9 patients (19%) following previous aortic surgery were identified. The incidence of AOF in the entire cohort after TEVAR in the study period was 1.5%. The primary underlying aortic pathology for TEVAR was atherosclerotic aneurysm formation in 53% of patients and the median time to development of AOF was 90 days (IQR 30-150). Leading clinical symptoms were fever of unknown origin in 29 (81%), haematemesis in 19 (53%) and shock in 8 (22%) patients. Diagnosis could be confirmed via computed tomography in 92% of the cases with the leading sign of a new mediastinal mass in 28 (78%) patients. A conservative approach resulted in a 100% 1-year mortality, and 1-year survival for an oesophageal stenting-only approach was 17%. Survival after isolated oesophagectomy was 43%. The highest 1-year survival rate (46%) could be achieved via an aggressive treatment including radical oesophagectomy and aortic replacement [relative risk increase 1.73 95% confidence interval (CI) 1.03-2.92]. The survival advantage of this aggressive treatment modality could be confirmed in bootstrap analysis (95% CI 1.11-3.33).
CONCLUSIONS:
The development of AOF is a rare but lethal complication after TEVAR, being associated with the need for emergency TEVAR as well as mediastinal haematoma formation. The only durable and successful approach to cure the disease is radical oesophagectomy and extensive aortic reconstruction. These findings may serve as a decision-making tool for physicians treating these complex patients
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The underlying causes of military outsourcing in the USA and UK: bridging the persistent gap between ends, ways and means since the beginning of the Cold War
This article reappraises the two most-studied country cases of military outsourcing: the USA and the UK. It argues that the contemporary wave of military contracting stretches back to the beginning of the cold war and not only to the demobilisation of armies in the 1990s or the neoliberal reforms introduced since the 1980s. It traces the political, technological and ideational developments that laid the groundwork for these reforms and practices since the early cold war and account for its endurance today. Importantly, it argues that a persistent gap between strategic objectives and resources, i.e. the challenge to reconcile ends and means, is an underlying driver of military contracting in both countries. Contemporary contracting is thus most closely tied to military support functions in support of wider foreign and defence political objectives. Security services in either state may not have been outsourced so swiftly, if at all, without decades of experience in outsourcing military logistics functions and the resultant vehicles, processes and familiarities with public-private partnerships. The article thus provides a wider and deeper understanding of the drivers of contractualisation, thereby improving our understanding of both its historical trajectory and the determinants of its present and potential futures
Blunted frequency-dependent upregulation of cardiac output is related to impaired relaxation in diastolic heart failure
Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography
<p>Abstract</p> <p>Background</p> <p>Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method.</p> <p>Methods</p> <p>Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE.</p> <p>Results</p> <p>There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP.</p> <p>Conclusion</p> <p>Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.</p
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