2,220 research outputs found
Determination of 2D implanted ion distributions using inverse radon transform methods
Two methods are presented for the experimental determination of 2D implanted ion distribution resulting from implantations with a line source into amorphous targets. It is shown that the relation between the 2D distribution and the depth profiles resulting from tilted angle implantations is described by the Radon transformation. The inverse transformation has been applied to accurately measured depth profiles. The first method uses a digitization of the 2D distribution and the second method uses a parameterized function for the 2D distribution. The methods are tested for a 400 keV boron implantation in an amorphous layer of silicon. The experimental obtained 2D distributions are compared with a TRIM Monte Carlo simulation. A good agreement between experiment and simulation is observed
The Influence of Genetic Variation on Von Willebrand Factor levels and the Risk of Stroke
__Abstract__
Cardiovascular disease (CVD), primarily due to arterial thrombus formation resulting
in vascular occlusion, is one of the most important causes of morbidity and mortality in
the world]. In the Netherlands, every day on average 51 males and 57 females die as a
result of CVD. Every year, CVD is responsible for nearly one third of total deaths. The
pathogenesis of CVD is highly complex. Both genetic factors and environmental factors
contribute, via complex interactions, to the pathogenesis of atherosclerosis, plaque rupture
and subsequent thrombus formation and vascular occlusion.
In the past, several risk factors for cardiovascular disease, such as smoking,
hypercholesterolemia and hypertension, have been identified. As coagulation factors,
including von Willebrand factor (VWF), are of major importance in the regulation of
thrombus formation, their role in CVD has also been investigated
Visual semantics
Veel betekenisaspecten van taal liggen opgeslagen in het semantische geheugen. Het semantische geheugen is gebaseerd op onze ervaring met concrete objecten zoals planten, dieren en gereedschappen. Onderzoek met mensen die als gevolg van een hersenbeschadiging moeite hebben met het begrijpen van taal, heeft uitgewezen dat de betekenis van taal ook afhankelijk is van diverse sensorische en motorische gebieden van de hersenen, met name de visuele hersengebieden. Het ventrale pad is betrokken bij het herkennen van objecten, het dorsale pad maakt het mogelijk acties uit te voeren met objecten. Resultaten van experimenten die in dit proefschrift beschreven zijn geven aan dat het semantische geheugen een zeer nauwe relatie onderhoudt met het visuele systeem in onze hersenen. Dit ondersteunt ook de gedachte van een model van visuele semantiek waarin visueel-beschrijvende informatie eerst wordt opgehaald uit het lange-termijngeheugen en vervolgens wordt geactiveerd in het object-werkgeheugen. Het werkgeheugen is waarschijnlijk van belang in de koppeling tussen talige en visuele informatie. Visuele semantiek ligt dus eigenlijk op het kruispunt van semantische, visuele en talige processen
Bron:Taaluniversum
Decoding atrial fibrillation:Personalized identification and quantification of electropathology
Electrophysiological mapping-guided ablation strategies targeting atrial fibrillation (AF) have improved considerably over the past few years. However, it remains a major challenge to design effective strategies for particularly persistent AF. This can be partially explained by the inadequate understanding of the mechanisms and electropathological substrate underlying AF. Progression of AF is accompanied by structural and electrical remodeling, resulting in complex electrical conduction disorders, which is defined as electropathology. The severity of electropathology thus defines the stage of AF and is a major determinant of the effectiveness of AF therapy. In this thesis, features of electrophysiological properties of atrial tissue have been explored, developed and quantified during normal sinus rhythm, programmed electrical stimulation and AF. In addition, inter- and intra-individual variation in these quantified parameters has been examined in patients with and without prior episodes of AF. The most suitable objective parameters will aid in the identification of patients at risk for early onset or progression of AF. Part I of this thesis focusses on quantified electrogram features related to electropathology. In part II, abnormalities in wavefront propagation due to heterogeneous conduction properties were explored. Part III focusses on identification of post-operative AF and the relation with electropathology. In part IV of this thesis, some clinical implications of high-resolution mapping during cardiac surgery and application of quantified electrophysiological features are discussed
Власть и управление
В современных условиях все больше внимания уделяется поискам оптимальной управленческой структуры. В статье рассматриваются общие и особенные моменты власти и управления; в частности, рассматриваются проблемы управления человеческими ресурсами предприятия.У сучасних умовах усе більше уваги приділяється пошукам оптимальної управлінської структури. У статті розглядаються загальні й особливі моменти влади і керування; зокрема, розглядаються проблеми керування людськими ресурсами підприємства.In modern conditions of more and more attention it is given searches of optimum administrative structure. In this article the general and especial moments of authority and management are considered; in particular, problems of management are considered by human resources of the enterprise
How to diagnose plantaris tendon involvement in midportion Achilles tendinopathy - clinical and imaging findings
Background: The purpose of this investigation was to evaluate if clinical assessment, Ultrasound + Colour Doppler (US + CD) and Ultrasound Tissue Characterisation (UTC) can be useful in detecting plantaris tendon involvement in patients with midportion Achilles tendinopathy. Methods: Twenty-three tendons in 18 patients (14 men, mean age: 37 years and 4 women: 44 years) (5 patients with bilateral tendons) with midportion Achilles tendinopathy were surgically treated with a scraping procedure and plantaris tendon removal. For all tendons, clinical assessment, Ultrasound + Colour Doppler (US + CD) examination and Ultrasound Tissue Characterisation (UTC) were performed. Results: At surgery, all 23 cases had a plantaris tendon located close to the medial side of the Achilles tendon. There was vascularised fat tissue in the interface between the Achilles and plantaris tendons. Clinical assessment revealed localised medial activity-related pain in 20/23 tendons and focal medial tendon tenderness in 20/23 tendons. For US + CD, 20/23 tendons had a tendon-like structure interpreted to be the plantaris tendon and localised high blood flow in close relation to the medial side of the Achilles. For UTC, 19/23 tendons had disorganised (type 3 and 4) echopixels located only in the medial part of the Achilles tendon indicating possible plantaris tendon involvement. Conclusions: US + CD directly, and clinical assessment indirectly, can detect a close by located plantaris tendon in a high proportion of patients with midportion Achilles tendinopathy. UTC could complement US + CD and clinical assessment by demonstrating disorganised focal medial Achilles tendon structure indicative of possible plantaris involvement
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