31 research outputs found

    Dynamic Human–Robot Collision Risk Based on Octree Representation

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    The automation of manufacturing applications where humans and robots operate in a shared environment imposes new challenges for presenting the operator’s safety and robot’s efficiency. Common solutions relying on isolating the robots’ workspace from human access during their operation are not applicable for HRI. This paper presents an extended reality-based method to enhance human cognitive awareness of the potential risk due to dynamic robot behavior towards safe human–robot collaborative manufacturing operations. A dynamic and state-aware occupancy probability map indicating the forthcoming risk of human–robot accidental collision in the 3D workspace of the robot is introduced. It is determined using octrees and is rendered in a virtual or augmented environment using Unity 3D. A combined framework allows the generation of both static zones (taking into consideration the entire configuration space of the robot) and dynamic zones (generated in real time by fetching the occupancy data corresponding to the robot’s current configuration), which can be utilized for short-term collision risk prediction. This method is then applied in a virtual environment of the workspace of an industrial robotic arm, and we also include the necessary technical adjustments for the method to be applied in an AR setting

    Novel direct factor IIa and Xa inhibitors: Mechanisms of action and preclinical studies

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    The need to overcome certain limitations of the existing anticoagulant agents (heparin, LMWH and VKAs) and to achieve more convenient long-term anticoagulation has fueled the quest for the "ideal anticoagulant", an agent that would exert at least similar antithrombotic effects with a substantially improved pharmacologic profile and significantly less bleeding complications. The major disadvantages of the traditional agents were the narrow therapeutic window with serious drug and food interactions and the need for regular blood monitoring. Coagulation factors IIa and Xa have proved the most attractive pharmacologic targets due to their key role in the coagulation process and the opportunity of blocking thrombin generation before the level of thrombin production that results in amplification of the anticoagulant effect while preserving some of thrombin hemostatic effect. This review summarizes the mechanism of action of some of the most promising novel oral direct factor IIa and Xa inhibitors with a focus on published preclinical trials that led to their clinical development. © 2012 Bentham Science Publishers

    Myeloperoxidase: Expressing inflammation and oxidative stress in cardiovascular disease

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    Myeloperoxidase (MPO), a heme protein released by leukocytes, is one of the most widely studied during the last decades molecule that plays a crucial role in inflammation and oxidative stress in the cellular level. It has become increasingly recognized that MPO performs a very important role as part of the innate immune system through the formation of microbicidal reactive oxidants, whilst it affects the arterial endothelium with a number of mechanisms that include modification of net cellular cholesterol flux and impairment of Nitric Oxide (NO)-induced vascular relaxation. In that way, MPO is implicated into both the formation and propagation of atheromatosis and there is substantial evidence that it also promotes ischemia through destabilization of the vulnerable plaque. Numerous studies have added information on the notion that MPO and its oxidant products are part of the inflammatory cascade initiated by endothelial injury and they are significantly overproduced at the site of arterial inflammation. Subsequent studies achieved quantification of this observation showing significant elevations of the systemic levels of MPO in a wide spectrum of cardiovascular disease scenarios with acute coronary syndromes and heart failure being the most studied. This review highlights key-aspects of MPO's pathophysiological properties and summarizes the role of MPO as a diagnostic and prognostic tool for a number of cardiovascular pathologies. © 2013 Bentham Science Publishers

    Adiponectin: Merely a bystander or the missing link to cardiovascular disease?

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    Adiponectin, a newly discovered adipose-tissue secreting hormone, is a major regulator of a wide spectrum of physiological processes, such as energy metabolism, inflammation and vascular homeostasis. Emerging data suggest that adiponectin is the link between obesity and obesity-related disorders with cardiovascular disease. Adiponectin is a dominant insulin-sensitive adipokine and, in contrast to other adipose-tissue derived cytokines, it has major anti-diabetic, antiatherogenic and anti-inflammatory properties. Adiponectin has been extensively studied in the context of several aspects and risk factors of cardiovascular disease such as obesity, diabetes type I and II, coronary heart disease, hypertension, heart failure, cerebrovascular disease and smoking. The aim of this article is to summarize the acquired so far knowledge on adiponectin in relation to cardiovascular disease, to review its main biological and biochemical characteristics, to highlight the main mechanisms of adiponectin-driven beneficial effects on vasculature and briefly to refer to the basic correlations of adiponectin with the important aforementioned aspects of cardiovascular disease. © 2013 Bentham Science Publishers

    Cystatin C: An emerging biomarker in cardiovascular disease

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    Cystatin C (cys-C) is a small protein molecule (120 amino acid peptide chain, approximately 13kDa) produced by virtually all nucleated cells in the human body. It belongs to the family of papain-like cysteine proteases and its main biological role is the extracellular inhibition of cathepsins. It's near constant production rate, the fact that it is freely filtered from the glomerular membrane and then completely reabsorbed without being secreted from the proximal tubular cells, made it an almost perfect candidate for estimating renal function. The strong correlation between chronic kidney disease (CKD) and cardiovascular disease (CVD) along with the growing understanding of the role of cysteinyl cathepsins in the pathophysiology of CVD inspired researchers to explore the potential association of cys-C with CVD. Throughout the spectrum of CVD (peripheral arterial disease, stroke, abdominal aortic aneurysm, heart failure, coronary artery disease) adverse outcomes and risk stratification have been associated with high plasma levels of cys-C. The exact mechanisms behind the observed correlations have not been comprehensively clarified. Plausible links between high cys-C levels and poor cardiovascular outcome could be impaired renal function, atherogenesis and inflammatory mediators, remodeling of myocardial tissue and others (genetic factors, aging and social habits). The scope of the present article is to systematically review the current knowledge about cys-C biochemistry, metabolism, methods of detection and quantification and pathophysiological associations with different aspects of CVD. © 2013 Bentham Science Publishers
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