473 research outputs found

    Advanced training model for beating heart coronary artery surgery: the Zurich heart-trainer

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    Objective: Coronary artery surgery with beating heart technique is gaining increasing popularity. However, it is a challenging technique even for well-trained cardiac surgeons. Thus, a training model for beating heart surgery was developed to increase safety and accuracy of this procedure. Methods: The model consists of differentially hardened polyurethane resembling mechanical properties of the human heart. The covering used in this model is a 1:1 replica of the human thoracic wall with optionally embedded skeletal structures. Sternotomy, lateral thoracotomy or trocar placement is possible to access the lungs, the pericardium and the heart with adjacent vessels. Disposable artificial coronaries variable in size, wall quality or wall thickness are embedded in the synthetic myocardium. Two-layer vessels, which can simulate dissection, are available. Bypass conduits utilize the same material. Coronaries/bypasses as well as part of the ascending aorta are water-tight and can be rinsed with saline. Lungs can be inflated. A purpose-built pump induces heart movement with adjustable or randomized stroke volume, heart rate and arrhythmia induction. Results: The model was tested in a recent ‘Wet-Lab' course attended by 30 surgeons. All conventional instruments and stabilizers with standard techniques can be used. Training with beating or non-beating heart was possible. Time needed for an anastomosis was similar to clinical experience. Each artificial tissue showed its individual nature-like qualities. Various degrees of difficulty can be selected, according to stroke volume, heart rate, arrhythmia, vessel size and vessel quality. The model can be quickly and easily set up and is fully reusable. Conclusions: The similarity to human tissue and the easy set-up make this completely artificial model an ideal teaching tool to increase the confidence of cardiac surgeons dealing with beating heart and minimally invasive surger

    Acute traumatic aortic rupture: early stent-graft repair

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    Objective: Prospective evaluation of early stent-graft repair of acute traumatic aortic rupture. Methods: Twelve patients with acute traumatic aortic rupture of the descending aorta, out of a series of 337 endovascular aortic procedures, were treated by implantation of self-expanding stent-grafts. The procedures were performed within a mean post-injury time-period of 5±7 days (median: 1 day). The feasibility of stent-grafting was assessed by CT scanning and echography. Implantation was performed under local (n=6), or general anesthesia (n=6) if patients were already intubated (n=5) or required a common iliac artery access (n=1). Results: The immediate technical success rate was 100%. There were no post-procedure complications in all but one patient, who died 12 h postoperatively (8% mortality). Complete sealing of the aortic rupture in the remaining 11 patients was confirmed by postoperative CT scans. There were no intervention-related morbidity or mortality during the mean follow-up of 17 months. One patient with peri-graft leakage was successfully repaired with an additional stent-graft 12 months postoperatively. Conclusion: Non-delayed or early stent-grafting in acute traumatic rupture of the descending aorta is feasible. This technique seems to be a valuable option, in particular when associated lesions may interfere with the surgical outcome. Immediate post-procedural CT scanning and/or echography should be performed, in order to rule out residual leakag

    Predictors of complications in acute type B aortic dissection

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    Objectives: Medical treatment is generally advocated for patients with acute type B aortic dissection without complications. The objective of this retrospective analysis was to determine whether there are any initial findings that can help predict the long-term course of the disease. Methods: Case records of the 130 patients treated for type B aortic dissection between 1988 and 1997 were reviewed; 41 (31%) were operated on in the acute phase (≪14 days), 31 (24%) were operated on in the chronic phase and 58 (45%) were treated medically. Results: Overall acute mortality was 10.8%; 22% for patients operated on in the early phase and 5.6% for medically treated patients. Age (P=0.002), persistent pain (P=0.01) and malperfusion (P=0.001) were significant independent predictors of the need for surgery. Paraplegia/para paresis (P=0.0001), leg ischaemia (P=0.003), pleural effusion (P=0.003), rupture (P=0.0001), shock (P=0.0001), age (P=0.003), cardiac failure (P=0.002) and aortic diameter ≫4.5cm (P=0.002) were significant predictors of poor survival. Age and shock also emerged as independent risk factors. Patients without malperfusion (P=0.0001), pleural effusion (P=0.003), rupture (P=0.0001) and shock (P=0.0001) had a significantly better event-free survival (freedom from repeat surgery and death). The actuarial survival rate for high-risk patients (malperfusion, rupture, shock) was 62% at 1 year and 40% at 5 years; the corresponding values for low-risk patients were 94 and 84%, respectively. Conclusions: Rupture, shock and malperfusion are significant predictors of poor survival in patients with acute type B aortic dissectio

    Simultane Behandlung von obliterativen Karotispathologien und koronarer Herzkrankheit: Aktuelles Konzept und Resultate der letzten 5Jahre

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    Zusammenfassung: Einführung: Die kombinierte Karotisendarteriektomie und aorto-coronare Baypassoperation (C-CABG) weisen ein hohes peri-operatives Risiko auf. Als Alternative wird in letzter Zeit das Stenting der Artera carotis interna propagiert. Das Fehlen von Level I Evidenz hat uns motiviert, die Resultate unserer C-CABG der letzten 5 Jahre zu evaluieren. Methoden und Patienten: Retrospektive Monozenterstudie von 113C-CABG, durchgeführt zwischen Januar 2000 und Dezember 2004. Das mediane Alter der Patienten betrug 65Jahre (22Patienten waren 80Jahre alt oder älter). Die Karotisendarteriektomie wurde vor der aortokoronaren Bypassoperation in derselben Narkose durchgeführt. Resultate: Die 30-Tages-Mortalität war ausschließlich kardial bedingt und betrug 4,4% (5/113). Die neurologischen Komplikationen waren ein Schlaganfall, der innerhalb von 30Tagen vollständig regredient war, und 3TIA (3,5%, 4/113). Schlussfolgerung: C-CABG mit initial durchgeführter Karotisendarteriektomie ist ein sicheres Verfahren mit niedriger neurologischer Komplikationsrate. Der riskante Anteil des kombinierten Eingriffs ist nicht die Karotisendarteriektomie, sondern die aortokoronare Revaskularisation. Demzufolge scheint das Stenting beim kombinierten Eingriff als Alternative nicht gerechtfertigt, solange keine klaren Vorteile hinsichtlich der Früh- und Langzeitresultate gegenüber der alleinigen Karotisendarteriektomie vorliege

    Dual-Element Isotope Analysis of Desphenylchloridazon to Investigate its Environmental Fate in a Systematic Field Study-A Long-Term Lysimeter Experiment

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    Desphenylchloridazon (DPC), the main metabolite of the herbicide chloridazon (CLZ), is more water soluble and persistent than CLZ and frequently detected in water bodies. When assessing DPC transformation in the environment, results can be nonconclusive if based on concentration analysis alone because estimates may be confounded by simultaneous DPC formation from CLZ. This study investigated the fate of DPC by combining concentration-based methods with compound-specific C and N stable isotope analysis (CSIA). Additionally, DPC formation and transformation processes were experimentally deconvolved in a dedicated lysimeter study considering three scenarios. First, surface application of DPC enabled studying its degradation in the absence of CLZ. Here, CSIA provided evidence of two distinct DPC transformation processes: one shows significant changes only in 13C/12C, whereas the other involves changes in both 13C/12C and 15N/14N isotope ratios. Second, surface application of CLZ mimicked a realistic field scenario, showing that during DPC formation, 13C/12C ratios of DPC were depleted in 13C relative to CLZ, while 15N/14N ratios remained constant. Finally, CLZ depth injection simulated preferential flow and demonstrated the importance of the topsoil for retaining DPC. The combination of the lysimeter study with CSIA enabled insights into DPC transformation in the field that are superior to those of studies of concentration trends

    Simultane Behandlung von obliterativen Karotispathologien und koronarer Herzkrankheit

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    Einführung: Die kombinierte Karotisendarteriektomie und aorto-coronare Baypassoperation (C-CABG) weisen ein hohes peri-operatives Risiko auf. Als Alternative wird in letzter Zeit das Stenting der Artera carotis interna propagiert. Das Fehlen von Level I Evidenz hat uns motiviert, die Resultate unserer C-CABG der letzten 5 Jahre zu evaluieren. Methoden und Patienten: Retrospektive Monozenterstudie von 113C-CABG, durchgeführt zwischen Januar 2000 und Dezember 2004. Das mediane Alter der Patienten betrug 65Jahre (22Patienten waren 80Jahre alt oder älter). Die Karotisendarteriektomie wurde vor der aortokoronaren Bypassoperation in derselben Narkose durchgeführt. Resultate: Die 30-Tages-Mortalität war ausschließlich kardial bedingt und betrug 4,4% (5/113). Die neurologischen Komplikationen waren ein Schlaganfall, der innerhalb von 30Tagen vollständig regredient war, und 3TIA (3,5%, 4/113). Schlussfolgerung: C-CABG mit initial durchgeführter Karotisendarteriektomie ist ein sicheres Verfahren mit niedriger neurologischer Komplikationsrate. Der riskante Anteil des kombinierten Eingriffs ist nicht die Karotisendarteriektomie, sondern die aortokoronare Revaskularisation. Demzufolge scheint das Stenting beim kombinierten Eingriff als Alternative nicht gerechtfertigt, solange keine klaren Vorteile hinsichtlich der Früh- und Langzeitresultate gegenüber der alleinigen Karotisendarteriektomie vorliege

    Acute traumatic aortic rupture: early stent-graft repair

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    Objective: Prospective evaluation of early stent-graft repair of acute traumatic aortic rupture. Methods: Twelve patients with acute traumatic aortic rupture of the descending aorta, out of a series of 337 endovascular aortic procedures, were treated by implantation of self-expanding stent-grafts. The procedures were performed within a mean post-injury time-period of 5±7 days (median: 1 day). The feasibility of stent-grafting was assessed by CT scanning and echography. Implantation was performed under local (n=6), or general anesthesia (n=6) if patients were already intubated (n=5) or required a common iliac artery access (n=1). Results: The immediate technical success rate was 100%. There were no post-procedure complications in all but one patient, who died 12 h postoperatively (8% mortality). Complete sealing of the aortic rupture in the remaining 11 patients was confirmed by postoperative CT scans. There were no intervention-related morbidity or mortality during the mean follow-up of 17 months. One patient with peri-graft leakage was successfully repaired with an additional stent-graft 12 months postoperatively. Conclusion: Non-delayed or early stent-grafting in acute traumatic rupture of the descending aorta is feasible. This technique seems to be a valuable option, in particular when associated lesions may interfere with the surgical outcome. Immediate post-procedural CT scanning and/or echography should be performed, in order to rule out residual leakag

    Beliefs about the Minds of Others Influence How We Process Sensory Information

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    Attending where others gaze is one of the most fundamental mechanisms of social cognition. The present study is the first to examine the impact of the attribution of mind to others on gaze-guided attentional orienting and its ERP correlates. Using a paradigm in which attention was guided to a location by the gaze of a centrally presented face, we manipulated participants' beliefs about the gazer: gaze behavior was believed to result either from operations of a mind or from a machine. In Experiment 1, beliefs were manipulated by cue identity (human or robot), while in Experiment 2, cue identity (robot) remained identical across conditions and beliefs were manipulated solely via instruction, which was irrelevant to the task. ERP results and behavior showed that participants' attention was guided by gaze only when gaze was believed to be controlled by a human. Specifically, the P1 was more enhanced for validly, relative to invalidly, cued targets only when participants believed the gaze behavior was the result of a mind, rather than of a machine. This shows that sensory gain control can be influenced by higher-order (task-irrelevant) beliefs about the observed scene. We propose a new interdisciplinary model of social attention, which integrates ideas from cognitive and social neuroscience, as well as philosophy in order to provide a framework for understanding a crucial aspect of how humans' beliefs about the observed scene influence sensory processing

    Diet and Physical Activity for the Prevention of Noncommunicable Diseases in Low- and Middle-Income Countries: A Systematic Policy Review

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    Background: Diet-related noncommunicable diseases (NCDs) are increasing rapidly in low-and middle-income countries (LMICs) and constitute a leading cause of mortality. Although a call for global action has been resonating for years, the progress in national policy development in LMICs has not been assessed. This review of strategies to prevent NCDs in LMICs provides a benchmark against which policy response can be tracked over time. Methods and Findings: We reviewed how government policies in LMICs outline actions that address salt consumption, fat consumption, fruit and vegetable intake, or physical activity. A structured content analysis of national nutrition, NCDs, and health policies published between 1 January 2004 and 1 January 2013 by 140 LMIC members of the World Health Organization (WHO) was carried out. We assessed availability of policies in 83% (116/140) of the countries. NCD strategies were found in 47% (54/116) of LMICs reviewed, but only a minority proposed actions to promote healthier diets and physical activity. The coverage of policies that specifically targeted at least one of the risk factors reviewed was lower in Africa, Europe, the Americas, and the Eastern Mediterranean compared to the other two World Health Organization regions, South-East Asia and Western Pacific. Of the countries reviewed, only 12% (14/116) proposed a policy that addressed all four risk factors, and 25% (29/116) addressed only one of the risk factors reviewed. Strategies targeting the private sector were less frequently encountered than strategies targeting the general public or policy makers. Conclusions: This review indicates the disconnection between the burden of NCDs and national policy responses in LMICs. Policy makers urgently need to develop comprehensive and multi-stakeholder policies to improve dietary quality and physical activity

    An 8-mm diameter fibre robot positioner for massive spectroscopy surveys

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    Massive spectroscopic survey are becoming trendy in astrophysics and cosmology, as they can address new fundamental knowledge such as understanding the formation of the Milky Way and probing the nature of the mysterious dark energy. To enable massive spectroscopic surveys, new technology has been developed to place thousands of optical fibres at a given position on a focal plane. This technology needs to be: (1) accurate, with micrometer positional accuracy; (2) fast to minimize overhead; (3) robust to minimize failure; and (4) low cost. In this paper, we present the development, properties, and performance of a new single 8-mm in diameter fibre positioner robot, using two 4-mm DC-brushless gearmotors, that allows us to achieve accuracies up to 0.07arcsec (5 μm). This device has been developed in the context of the Dark Energy Spectroscopic Instrument.
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