524 research outputs found
Non-Vitamin K Oral Anticoagulants (NOAC) Versus Vitamin K Antagonists (VKA) for Atrial Fibrillation with Elective or Urgent Percutaneous Coronary Intervention: A Meta-Analysis with a Particular Focus on Combination Type
No full textBackground: Our study aims to perform a meta-analysis of benefits and risks associated with the use of non-vitamin K oral anticoagulants (NOAC) versus vitamin K antagonists (VKA) in patients with a percutaneous coronary intervention (PCI) with a particular focus on the combination type: dual vs. dual antithrombotic therapy (DAT: NOAC + single antiplatelet therapy (SAPT) vs. DAT: VKA + SAPT), dual vs. triple antithrombotic therapy (DAT: NOAC + SAPT vs. TAT: VKA + dual antiplatelet therapy (DAPT)) or triple vs. triple antithrombotic therapy (TAT: NOAC+DAPT vs. TAT: VKA+DAPT). Methods: PubMed, EMBASE, and Cochrane databases were searched to identify randomized controlled trials comparing antithrombotic regimens. Four randomized studies (n = 10.969; PIONEER AF-PCI, RE-DUAL PCI, AUGUSTUS, and ENTRUST-AF PCI) were included. The primary outcome was the composite of major bleeding defined by the International Society on Thrombosis and Hemostasis (ISTH) and clinically relevant bleeding requiring medical intervention (CRNM). Secondary outcomes included all-cause mortality, major adverse cardiovascular events (MACE), myocardial infarction (MI), stroke, and stent thrombosis (ST). Results: Combination strategies with NOACs were associated with reduced risk of major bleeding events across different combination strategies as compared to VKA, with the most significant risk reduction when DAT was compared with TAT, namely DAT with NOAC + SAPT was associated with a 37% relative risk reduction (RRR) of major bleeding events as compared to TAT with VKA + DAPT (RR 0.63; 95% CI, 0.50-0.80). The reduction of major bleeding risks is a class effect of NOACs. Combination strategies of NOACs vs. VKAs resulted in a comparable risk of MACE, MI, stroke, ST, or death. Conclusions: Antithrombotic combinations of NOACs (as DAT or TAT) are safer than VKAs with respect to bleeding risk and result in a satisfactory efficacy with no increase of ischemic or thrombotic events in patients undergoing PCI
Novel antiplatelet agents in the prevention of cardiovascular complications – focus on ticagrelor
No full textMargaret M Marczewski1, Marek Postula1,2, Dariusz Kosior111st Chair and Department of Cardiology, Central University Hospital, Medical University of Warsaw, Warsaw, Poland; 2Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Warsaw, PolandAbstract: Atherothrombosis, thrombus formation as a result of atherosclerotic plaque rupture, is a major modern health problem, often underlying coronary artery disease, stroke, and peripheral arterial disease. After the treatment of an acute thrombotic episode, long-term therapy is warranted as a secondary prophylaxis of such events and their complications. Because of the importance of platelets’ involvement in the initiation and propagation of thrombosis, antiplatelet drugs have come to the forefront of atherothrombotic disease treatment. Dual antiplatelet therapy of aspirin plus clopidogrel – the current standard – has its benefits, but it also has its limitations with regard to its pharmacologic properties and adverse effects. For these reasons, within the last decade or so, the investigation of novel antiplatelet agents has prospered. Here, we review the main pathways through which platelets participate in acute thrombosis and the interruption of these pathways by using novel antiplatelet agents, including P2Y12 receptor antagonists (the recently approved prasugrel, the probable next-in-line ticagrelor, and others). The need for a more individualized patient therapy is evident; although most of the aforementioned pharmaceuticals have the potential to contribute to this, their clinical utility remains to be seen.Keywords: antiplatelet therapy, antagonist, P2Y12 receptor, ADP recepto
Novel antiplatelet agents in the prevention of cardiovascular complications – focus on ticagrelor
No full textAssessing an FPGA implemented MIMO testbed with the use of channel emulator
No full textIn this paper, a channel emulator for assessing the performance of MIMO testbed implemented in a field programmable gate array technology is described. The FPGA based MIMO system includes a signal generator, modulation/demodulation and space time coding/decoding modules. The emulator uses information about a wireless channel from computer simulations or actual measurements. In simulations, a single bounce scattering model for an indoor environment is applied. The generated data is stored in the FPGA board. The tests are performed for a 2times2 MIMO system that uses Alamouti scheme for space coding/decoding. The performed tests show proper operation of the FPGA implemented MIMO testbed. Good agreement between the results using measured and simulated channel data is obtained
Field programmable gate array based testbed for investigating multiple input multiple output signal transmission in indoor environments
No full textThis chapter introduces the concept of Multiple Input Multiple Output (MIMO) wireless communication system and the necessity to use a testbed to evaluate its performance. A comprehensive review of different types of testbeds available in the literature is presented. Next, the design and development of a 2×2 MIMO testbed which uses in-house built antennas, commercially available RF chips for an RF front end and a Field Programmable Gate Array (FPGA) for based signal processing is described. The operation of the developed testbed is verified using a Channel Emulator. The testing is done for the case of a simple Alamouti QPSK based encoding and decoding scheme of baseband signals
El proceso de nuestro conocer postula un nuevo paradigma epistémico
No full textThe article discusses approaches that come to apply that science has to be redone again, which is part of a major premise that the modern age has ended and we are going through a transition period. Thus, it would be only a crisis of the foundations of scientific knowledge, but also philosophical, and generally in a crisis of the foundations of thought. It is noted that open up to this critical examination may bring out many flaws in logic that have been making a habit in many sectors of academic life. The author presents the theory and the theory of knowledge reference of logical positivism, to continue his questioning, after which presents the foundations for a new epistemic paradigm, linking them to their authors and proponents.El artículo aborda planteamientos que llegan a postular que la ciencia ha de rehacerse de nuevo, lo que se inscribe en un postulado mayor de que la edad moderna ha terminado y que estamos atravesando un período de transición. Así, no estaríamos solamente ante una crisis de los fundamentos del conocimiento científico, sino también del filosófico, y, en general, ante una crisis de los fundamentos del pensamiento. Se señala que abrirse a este examen crítico podrá poner en evidencia muchos vicios de lógica que se han ido convirtiendo en hábito en amplios sectores de la vida académica. El autor expone la teoría como referencia la teoría del conocimiento del positivismo lógico, para seguir con su cuestionamiento, tras lo cual presenta los basamentos para un nuevo paradigma epistémico, relacionándolos con sus autores y proponentes
Investigations into diversity of A 2x2 MIMO system with the use of an indoor testbed
No full textThis paper presents investigations into an indoor 2×2 multiple input multiple output (MIMO) system, whose diversity performance is assessed using a high precision test-bed. In this system, transmitter and receiver are equipped with 180° or 90° 3dB hybrids with their two output ports terminated with co-polar monopole antennas. By feeding a signal to one of the two input ports of the hybrid (while the other input port is matched terminated) different communication channels in a rich-scattering environment can be created. The test-bed allows for the signal strength measurements around the receiver/ transmitter sides for a given feeding configuration of hybrids when the receiver is moved over a circular region in an indoor environment. The signal strengths maps obtained for various modes of this 2×2 MIMO system are foundations for investigating transmit/receive diversity schemes. As the signal strength measurement results are obtained with Bluetooth modules operating in the ISM 2.4 GHz, the results are of importance to many other wireless systems that aim at utilizing MIMO diversity schemes to enhance their performance in this frequency band
El proceso de nuestro conocer postula un nuevo paradigma epistémico
No full textEl artículo aborda planteamientos que llegan a postular que la ciencia ha de rehacerse de nuevo, lo que se inscribe en un postulado mayor de que la edad moderna ha terminado y que estamos atravesando un período de transición. Así, no estaríamos solamente ante una crisis de los fundamentos del conocimiento científico, sino también del filosófico, y, en general, ante una crisis de los fundamentos del pensamiento. Se señala que abrirse a este examen crítico podrá poner en evidencia muchos vicios de lógica que se han ido convirtiendo en hábito en amplios sectores de la vida académica. El autor expone la teoría como referencia la teoría del conocimiento del positivismo lógico, para seguir con su cuestionamiento, tras lo cual presenta los basamentos para un nuevo paradigma epistémico, relacionándolos con sus autores y proponentes.L’article aborde des positions qui défendent que la science doit être repensée, s’inscrivant dans une posture plus ample postulant que l’ère moderne est arrivée à terme, et que nous traversons une période de transition. Ainsi, nous serions en présence d’une crise des fondements de la connaissance aussi bien scientifique que philosophique, et, en général, face à une crise des fondements de la pensée. S’ouvrir à ce type d’analyse critique pourrait mettre en évidence de nombreux vices de logique qui se sont peu à peu convertis en habitudes pour de nombreux secteurs de la vie académique. L’auteur expose la théorie comme référence la théorie de la connaissance du positivisme logique, pour poursuivre avec sa remise en question, puis il présente les fondements pour un nouveau paradigme épistémique, en l’associant à ses auteurs et défenseurs.The article discusses approaches that come to apply that science has to be redone again, which is part of a major premise that the modern age has ended and we are going through a transition period. Thus, it would be only a crisis of the foundations of scientific knowledge, but also philosophical, and generally in a crisis of the foundations of thought. It is noted that open up to this critical examination may bring out many flaws in logic that have been making a habit in many sectors of academic life. The author presents the theory and the theory of knowledge reference of logical positivism, to continue his questioning, after which presents the foundations for a new epistemic paradigm, linking them to their authors and proponents
MIMO tested with an insight into signal strength distribution around transmitter/receiver sites
No full textThis paper presents a high precision test-bed to obtain an insight into the operation of a multiple element antenna (MEA) communication system in an indoor environment. In this system, transmitter and receiver are equipped with 180° or 90° 3dB hybrids whose two output ports are terminated with co-polar monopole antennas. By feeding the signal to one of the remaining two ports of the hybrids various radiation patterns are established. These in turn create various communication channels formed by MEA and a surrounding scattering environment. The testbed allows for the signal strength measurements around the receiver/transmitter sides for various radiation pattern modes generated by transmitting and receiving array antennas operating in conjuncture with the hybrids. Details concerning mechanical, electrical and electronics hardware and associated measurement software are described. Initial measurement results in the ISM 2.4 GHz band for a 2×2 MEMO system that includes Bluetooth modules equipped with planar monopoles and 180°/90° hybrids are given
- …
