1,721,007 research outputs found
Refractory angina despite patent coronary artery bypass grafts: treatment with transmyocardial laser revascularization and scintigraphic evidence of improved myocardial perfusion
No full textProgression of coronary artery disease that causes recurrent angina in patients who have already undergone coronary artery bypass grafting (CABG) is a challenge to cardiac surgeons. The presence of myocardial ischemia that is not due to bypass grafts occlusion, but to the quality of the coronary vessels characterized by diffuse atherosclerotic peripheral disease, makes the situation even more difficult, since it is not possible to perform myocardial revascularization either by percutaneous transluminal angioplasty (PTCA) or by means of new grafts. We report the case of a patient who, 4 years after triple CABG, developed refractory angina despite patency of bypass grafts (to left anterior descending artery, obtuse marginal branch and posterior descending) and maximally tolerated conventional medical treatment. Native coronary arteries were occluded. Because of the exiguous caliber of the distal portion of epicardial vessels and poor run-off, a redo CABG was judged to be unfeasible. Transmyocardial laser revascularization (TMLR) was performed through left anterior thoracotomy, minimizing the risk of damage to the grafts. Clinical improvement (from CCS class IV to 0) and scintiscan showing improved myocardial perfusion to the laser-treated regions confirm the effectiveness of TMLR in otherwise inoperable coronary artery disease
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A novel approach for security function graph configuration and deployment
Full text linkNetwork virtualization increased the versatility in enforcing security protection, by easing the development of new security function implementations. However, the drawback of this opportunity is that a security provider, in charge of configuring and deploying a security function graph, has to choose the best virtual security functions among a pool so large that makes manual decisions unfeasible. In light of this problem, the paper proposes a novel approach for synthesizing virtual security services by introducing the functionality abstraction. This new level of abstraction allows to work in the virtual level without considering the different function implementations, with the objective to postpone the function selection jointly with the deployment, after the configuration of the virtual graph. This novelty enables to optimize the function selection when the pool of available functions is very large. A framework supporting this approach has been implemented and it showed adequate scalability for the requirements of modern virtual networks
Automated optimal firewall orchestration and configuration in virtualized networks
Full text linkEmerging technologies such as Software-Defined Networking and Network Functions Virtualization are making the definition and configuration of network services more dynamic, thus making automatic approaches that can replace manual and error-prone tasks more feasible. In view of these considerations, this paper proposes a novel methodology to automatically compute the optimal allocation scheme and configuration of virtual firewalls within a user-defined network service graph subject to a corresponding set of security requirements. The presented framework adopts a formal approach based on the solution of a weighted partial MaxSMT problem, which also provides good confidence about the solution correctness. A prototype implementation of the proposed approach based on the z3 solver has been used for validation, showing the feasibility of the approach for problem instances requiring tens of virtual firewalls and similar numbers of security requirements
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Temporary Neurological Dysfunction After Minimal Invasive Mitral Valve Surgery: Influence of Type of Perfusion and Aortic Clamping Technique
No full textRight Mini-thoracotomy Mitral Valve Surgery: The Art and Science of the Tailoring Approach
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