1,320 research outputs found

    Cardiac Calcitropes, Myotropes, and Mitotropes: JACC Review Topic of the Week.

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    The term "inotrope" is familiar and intimately connected with pharmaceuticals clinically used for treatment of low cardiac output with cardiogenic shock. Traditional inotropic agents exert their effect by modulating calcium signaling in the myocardium. Their use is associated with poor long-term outcomes. Newer molecules in development intend to break from calcium mediation and the associated detrimental long-term effects by targeting distinct mechanisms of action to improve cardiac performance. Thus, "inotropy" does not sufficiently describe the range of potential novel pharmaceutical products. To enhance communication around and evaluation of current, emerging, and potential therapies, this review proposes a novel nuanced and holistic framework to categorize pharmacological agents that improve myocardial performance based on 3 myocardial mechanisms: calcitropes, which alter intracellular calcium concentrations; myotropes, which affect the molecular motor and scaffolding; and mitotropes, which influence energetics. Novel chemical entities can easily be incorporated into this structure, distinguishing themselves based on their mechanisms and clinical outcomes

    Veiled Women in the American Courtroom: Is the Niqab a Barrier to Justice?

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    U.S. courts and policy-makers have recently authorized laws and practices that interfere with the wearing of religious modesty attire that conceals the hair or face in contexts such as courtroom testimony or driver’s license issuance. For example, in response to a court’s dismissal of the case of a woman who refused to remove her niqab in the courtroom, the Michigan Supreme Court decided that judges can exercise “reasonable control” over the appearance of courtroom parties. But what degree of control over religious attire is reasonable? The Constitution will not allow a blanket niqab removal policy based on any of the following needs: to judge demeanor or veracity, to identify witnesses, to compel accountability, or to identify and avert bias. Where the state’s interest in niqab removal is truly compelling, for the sake of religious free exercise it should be protected in the least restrictive manner. I argue that because Muslim women who wear the niqab in the courtroom are neither disruptive nor an affront to the dignity of the court, their religious freedom to dress modestly should be accommodated in straightforward and available ways

    Manipulating infrared photons using plasmons in transparent graphene superlattices

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    Superlattices are artificial periodic nanostructures which can control the flow of electrons. Their operation typically relies on the periodic modulation of the electric potential in the direction of electron wave propagation. Here we demonstrate transparent graphene superlattices which can manipulate infrared photons utilizing the collective oscillations of carriers, i.e., plasmons of the ensemble of multiple graphene layers. The superlattice is formed by depositing alternating wafer-scale graphene sheets and thin insulating layers, followed by patterning them all together into 3-dimensional photonic-crystal-like structures. We demonstrate experimentally that the collective oscillation of Dirac fermions in such graphene superlattices is unambiguously nonclassical: compared to doping single layer graphene, distributing carriers into multiple graphene layers strongly enhances the plasmonic resonance frequency and magnitude, which is fundamentally different from that in a conventional semiconductor superlattice. This property allows us to construct widely tunable far-infrared notch filters with 8.2 dB rejection ratio and terahertz linear polarizers with 9.5 dB extinction ratio, using a superlattice with merely five graphene atomic layers. Moreover, an unpatterned superlattice shields up to 97.5% of the electromagnetic radiations below 1.2 terahertz. This demonstration also opens an avenue for the realization of other transparent mid- and far-infrared photonic devices such as detectors, modulators, and 3-dimensional meta-material systems.Comment: under revie

    Endoscopic Saphenous harvesting with an Open CO2 System (ESOS) trial for coronary artery bypass grafting surgery: study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>In coronary artery bypass grafting surgery, arterial conduits are preferred because of more favourable long-term patency and outcome. Anyway <it>the greater saphenous vein </it>continues to be the most commonly used bypass conduit. <it>Minimally invasive endoscopic saphenous vein harvesting </it>is increasingly being investigated in order to reduce the morbidity associated with conventional open vein harvesting, includes postoperative leg wound complications, pain and patient satisfaction. However, to date the short and the long-term benefits of the endoscopic technique remain controversial. This study provides an interesting opportunity to address this gap in the literature.</p> <p>Methods/Design</p> <p><b>Endoscopic Saphenous harvesting with an Open CO<sub>2 </sub>System </b>trial includes two parallel vein harvesting arms in coronary artery bypass grafting surgery. It is an interventional, single centre, prospective, randomized, safety/efficacy, cost/effectiveness study, in adult patients with elective planned and first isolated coronary artery disease. A simple size of 100 patients for each arm will be required to achieve 80% statistical power, with a significant level of 0.05, for detecting most of the formulated hypotheses. A six-weeks leg wound complications rate was assumed to be 20% in the conventional arm and less of 4% in the endoscopic arm. Previously quoted studies suggest a first-year vein-graft failure rate of about 20% with an annual occlusion rate of 1% to 2% in the first six years, with practically no difference between the endoscopic and conventional approaches. Similarly, the results on event-free survival rates for the two arms have barely a 2-3% gap. Assuming a 10% drop-out rate and a 5% cross-over rate, the goal is to enrol 230 patients from a single Italian cardiac surgery centre.</p> <p>Discussion</p> <p>The goal of this prospective randomized trial is to compare and to test improvement in wound healing, quality of life, safety/efficacy, cost-effectiveness, short and long-term outcomes and vein-graft patency after endoscopic open CO<sub>2 </sub>harvesting system versus conventional vein harvesting.</p> <p>The expected results are of high clinical relevance and will show the safety/efficacy or non-inferiority of one treatment approach in terms of vein harvesting for coronary artery bypass grafting surgery.</p> <p>Trial registration</p> <p>www.clinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01121341">NCT01121341</a>.</p

    The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

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    Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4

    Assessing Predation Risk to Threatened Fauna from their Prevalence in Predator Scats: Dingoes and Rodents in Arid Australia

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    The prevalence of threatened species in predator scats has often been used to gauge the risks that predators pose to threatened species, with the infrequent occurrence of a given species often considered indicative of negligible predation risks. In this study, data from 4087 dingo (Canis lupus dingo and hybrids) scats were assessed alongside additional information on predator and prey distribution, dingo control effort and predation rates to evaluate whether or not the observed frequency of threatened species in dingo scats warrants more detailed investigation of dingo predation risks to them. Three small rodents (dusky hopping-mice Notomys fuscus; fawn hopping-mice Notomys cervinus; plains mice Pseudomys australis) were the only threatened species detected in <8% of dingo scats from any given site, suggesting that dingoes might not threaten them. However, consideration of dingo control effort revealed that plains mice distribution has largely retracted to the area where dingoes have been most heavily subjected to lethal control. Assessing the hypothetical predation rates of dingoes on dusky hopping-mice revealed that dingo predation alone has the potential to depopulate local hopping-mice populations within a few months. It was concluded that the occurrence of a given prey species in predator scats may be indicative of what the predator ate under the prevailing conditions, but in isolation, such data can have a poor ability to inform predation risk assessments. Some populations of threatened fauna assumed to derive a benefit from the presence of dingoes may instead be susceptible to dingo-induced declines under certain conditions

    Meditation Awareness Training (MAT) for Work-related Wellbeing and Job Performance: A Randomised Controlled Trial

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    Due to its potential to concurrently improve work-related wellbeing (WRW) and job performance, occupational stakeholders are becoming increasingly interested in the applications of meditation. The present study conducted the first randomized controlled trial to assess the effects of meditation on outcomes relating to both WRW and job performance. Office-based middle-hierarchy managers (n = 152) received an eight-week meditation intervention (Meditation Awareness Training; MAT) or an active control intervention. MAT participants demonstrated significant and sustainable improvements (with strong effect sizes) over control-group participants in levels of work-related stress, job satisfaction, psychological distress, and employer-rated job performance. There are a number of novel implications: (i) meditation can effectuate a perceptual shift in how employees experience their work and psychological environment and may thus constitute a cost-effective WRW intervention, (ii) meditation-based (i.e., present-moment-focussed) working styles may be more effective than goal-based (i.e., future-orientated) working styles, and (iii) meditation may reduce the separation made by employees between their own interests and those of the organizations they work for

    SILAC-based proteomic quantification of chemoattractant-induced cytoskeleton dynamics on a second to minute timescale

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    Cytoskeletal dynamics during cell behaviours ranging from endocytosis and exocytosis to cell division and movement is controlled by a complex network of signalling pathways, the full details of which are as yet unresolved. Here we show that SILAC-based proteomic methods can be used to characterize the rapid chemoattractant-induced dynamic changes in the actin–myosin cytoskeleton and regulatory elements on a proteome-wide scale with a second to minute timescale resolution. This approach provides novel insights in the ensemble kinetics of key cytoskeletal constituents and association of known and novel identified binding proteins. We validate the proteomic data by detailed microscopy-based analysis of in vivo translocation dynamics for key signalling factors. This rapid large-scale proteomic approach may be applied to other situations where highly dynamic changes in complex cellular compartments are expected to play a key role

    Family physicians' perceptions of academic detailing: a quantitative and qualitative study

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    <p>Abstract</p> <p>Background</p> <p>The efficacy of academic detailing in changing physicians' knowledge and practice has been the subject of many primary research publications and systematic reviews. However, there is little written about the features of academic detailing that physicians find valuable or that affect their use of it. The goal of our project was to explore family physicians' (FPs) perceptions of academic detailing and the factors that affect their use of it.</p> <p>Methods</p> <p>We used 2 methods to collect data, a questionnaire and semi-structured telephone interviews. We mailed questionnaires to all FPs in the Dalhousie Office of Continuing Medical Education database and analyzed responses of non-users and users of academic detailing. After a preliminary analysis of questionnaire data, we conducted semi-structured interviews with 7 FPs who did not use academic detailing and 17 who did use it.</p> <p>Results</p> <p>Overall response rate to the questionnaire was 33% (289/869). Response rate of non-users of academic detailing was 15% (60/393), of users was 48% (229/476). The 3 factors that most encouraged use of academic detailing were the topics selected, the evidence-based approach adopted, and the handout material. The 3 factors that most discouraged the use of academic detailing were spending office time doing CME, scheduling time to see the academic detailer, and having CME provided by a non-physician. Users of academic detailing rated it as being more valuable than other forms of CME. Generally, interview data confirmed questionnaire data with the exception that interview informants did not view having CME provided by a non-physician as a barrier. Interview informants mentioned that the evidence-based approach adopted by academic detailing had led them to more critically evaluate information from other CME programs, pharmaceutical representatives, and journal articles, but not advice from specialists.</p> <p>Conclusion</p> <p>Users of academic detailing highly value its educational value and tend to view information from other sources more critically because of its evidence-based approach. Non-users are unlikely to adopt academic detailing despite its high educational value because they find using office time for CME too much of a barrier. To reach these physicians with academic detailing messages, we will have to find other CME formats.</p
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