Search for dissertations about: "monophasic"

Showing result 1 - 5 of 25 swedish dissertations containing the word monophasic.

2. 1. Global sequence and dispersion of ventricular repolarization: In vivo validation of non-invasive parameters using monophasic action potential mapping technique

   Author : Yunlong Xia; Kardiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kardiovaskulära systemet; Cardiovascular system; dispersion; electroanatomical mapping; T wave; epicardial pacing; Ventricular repolarization; monophasic action potential;

   Abstract : The purposes are to validate the noninvasive parameters, QT interval, QT dispersion, Tpeak-Tend interval, and the activation recovery time (ART) for estimation of global dispersion of ventricular repolarization (DVR), and to investigate the changes of repolarization sequence and DVR by altered ventricular pacing sites. The material consisted of 12 patients (Study I) and two series healthy pigs with 10 in each (Studies II and III; Studies IV and V). READ MORE

4. 2. SEQUENCE AND DISPERSION OF VENTRICULAR REPOLARIZATION ON THE ENDOCARDIUM AND EPICARDIUM Studies using the monophasic action potential mapping technique in humans and pigs

   Author : Ole Kongstad Rasmussen; Kardiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cardiovascular system; Kardiovaskulära systemet; ventricle; epicardium; endocardium; Monophasic action potential mapping Repolarization sequence; Global dispersion;

   Abstract : Materials and Methods: Monophasic action potential (MAP) were recorded, using the CARTO mapping system and NaviStar catheters, during sinus rhythm from the endocardium at 43 ± 15 LV or RV sites in 8 patients, at 61 ± 18 LV and/or RV sites in 10 pigs and during atrial pacing from the endo- and epicardium at 211 ± 54 LV and RV sites in additional 10 pigs. Local activation time (AT), MAP duration (MAPd) and end-of-repolarization time (EOR) were calculated at each site and 3-dimensional maps of AT, EOR and MAP duration on the endo- and epicardium were obtained. READ MORE

5. 3. Immunoregulation and immunogenetics of monophasic and relapsing experimental autoimmune encephalomyelitis with emphasis on cytokines

   Author : Shohreh Issazadeh; Karolinska Institutet; Karolinska Institutet; []
   Keywords : ;

   Abstract : Experimental autoimmune encephalomyelitis (EAE) is a CD4+ T cell mediated autoimmune disease of the central nervous system (CNS) that resembles multiple sclerosis (MS). An MS-like histopathology and disease course can be provoked by immunization of susceptible animals with inoculum containing CNS antigens. READ MORE

6. 4. Sequence and dispersion of repolarization of the right atrium: Implications of repolarization disturbance in atrial fibrillation

   Author : Zhen Li; Kardiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kardiovaskulära systemet; Cardiovascular system; electroanatomical mapping; monophasic action potential; atrial fibrillation; repolarization; dispersion;

   Abstract : To explore the global sequence and dispersion of repolarization of the right atrium, monophasic action potentials (MAPs) were sequentially recorded from the right atrium using an electroanatomical mapping (CARTO) system in 10 healthy pigs and in 10 patients with (n=6) and without (n=4) paroxysmal atrial fibrillation (PAF) during sinus rhythm, or using two MAP recording catheters in 30 patients with or without PAF (n=15 each) during sinus rhythm, pacing, and programmed stimulation. The dispersion of activation time (AT), repolarization time (RT) and MAP duration (MAPd) were analyzed. READ MORE

7. 5. Spark Plasma Sintering of Si3N4-based Ceramics : Sintering mechanism-Tailoring microstructure-Evaluationg properties

   Author : Hong Peng; Zhijian (James) Shen; Mats Nygren; Michael J. Hoffmann; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; spark plasma sintering; silicon nitride ceramics; grain growth kinetic; superplasiticity; liqiud phase sintering; Chemistry; Kemi;

   Abstract : Spark Plasma Sintering (SPS) is a promising rapid consolidation technique that allows a better understanding and manipulating of sintering kinetics and therefore makes it possible to obtain Si3N4-based ceramics with tailored microstructures, consisting of grains with either equiaxed or elongated morphology. The presence of an extra liquid phase is necessary for forming tough interlocking microstructures in Yb/Y-stabilised α-sialon by HP. READ MORE