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Validity, reliability and responsiveness of the "Schedule for the Evaluation of Individual Quality of Life – Direct Weighting" (SEIQoL-DW) in congenital heart disease
Philip Moons, Kristel Marquet, Werner Budts, Sabina De Geest
Health and Quality of Life Outcomes , 2004, DOI: 10.1186/1477-7525-2-27
Abstract: We evaluated validity evidence based on test content, internal structure, and relations to other variables, as well as the stability and responsiveness of the SEIQoL-DW. Evidence was provided by both theoretical considerations and empirical data. Empirical data were acquired from two studies. Firstly, using a cross-sectional study design, we included 629 patients with congenital heart disease. Secondly, 130 of the 629 initially included patients readministered the questionnaires approximately one year after the first data collection. In addition to the SEIQoL-DW, linear analog scales were used to assess overall quality of life and perceived health.We found that the SEIQoL-DW is not a valid measure of quality of life, but rather assesses determinants that contribute to individuals' quality of life. The SEIQoL-DW consistently proved to be valid and reliable to assess those determinants. However, responsiveness in patients with congenital heart disease may be problematic.Based on theoretical and empirical considerations, the SEIQoL-DW cannot be considered as a quality of life instrument. Nonetheless, it is a valid and reliable instrument to explore determinants for patients' quality of life.Quality of life is an increasingly popular concept, as illustrated by an exponential growth of quality of life studies in medical, nursing and health services literature. It has emerged as an important variable for evaluating the quality and outcome of provided health care. For this purpose, a vast amount of tools have been developed to measure quality of life. Most of them are standardized questionnaires or test batteries to obtain information on patients' functioning or self-perceived health.About 15 years ago, the use of standard tools for measuring quality of life began to be criticized for several reasons. First, such predetermined tools contain items that may not be relevant for all individuals whose quality of life is assessed [1]. Even when tools are constructed based on dat
Early bare-metal stent thrombosis presenting with cardiogenic shock: a case report
Konstantinos M Lampropoulos, Themistoklis A Iliopoulos, Werner Budts
Journal of Medical Case Reports , 2011, DOI: 10.1186/1752-1947-5-509
Abstract: We present the case of a 64-year-old Caucasian man from Greece, with symptoms and electrocardiographic findings suggestive of acute inferior myocardial infarction, who complained of chest pain and rapidly developed cardiogenic shock 48 hours after primary percutaneous coronary intervention.The most common cause of early bare-metal stent thrombosis is stent malapposition. Intravascular ultrasound is the preferred method to recognize predictors of coronary events that are not detected by angiography.Stents have improved the safety and efficacy of percutaneous coronary interventions (PCI) by reducing acute or imminent vessel closure and by reducing restenosis rates compared with conventional balloon angioplasty [1]. In addition, coronary vasomotor reactivity has been found intact after stent implantation and long-term clinical and angiographic follow-up have attested to the durability of their action [2]. Nevertheless, coronary stent thrombosis remains a serious complication of PCI.A 64-year-old male Caucasian patient was admitted to our hospital with clinical and electrocardiographical findings suggesting acute inferior myocardial infarction. Our patient had a history of hypertension and dyslipidemia but was not taking any medication at the time of admission. Laboratory findings were suggestive of acute cardiac ischemia. His plasma levels of N-terminal pro-B-type natriuretic, troponin I, creatine kinase and creatine kinase MB isoenzyme were increased. The first transthoracic echocardiogram executed at our emergency department showed hypokinesia of the inferior and posterior left ventricular wall. Our patient received 600 mg clopidogrel, 325 mg aspirin and 5000 U of unfractionated heparin and was then transferred to the catheterization laboratory, while receiving glycoprotein IIb/IIIa inhibitors (abciximab) intravenously.Coronary angiography showed atheromatosis of his left anterior descending artery and his left circumflex artery without any evidence of severe stenose
Serial exercise testing in children, adolescents and young adults with Senning repair for transposition of the great arteries
Buys Roselien,Budts Werner,Reybrouck Tony,Gewillig Marc
BMC Cardiovascular Disorders , 2012, DOI: 10.1186/1471-2261-12-88
Abstract: Background Patients with Senning repair for complete transposition of the great arteries (d-TGA) show an impaired exercise tolerance. Our aim was to investigate changes in exercise capacity in children, adolescents and adults with Senning operation. Methods Peak oxygen uptake (peak VO2), oxygen pulse and heart rate were assessed by cardiopulmonary exercise tests (CPET) and compared to normal values. Rates of change were calculated by linear regression analysis. Right ventricular (RV) function was assessed by echocardiography. Results Thirty-four patients (22 male) performed 3.5 (range 3–6) CPET with an interval of ≥ 6 months. Mean age at first assessment was 16.4 ± 4.27 years. Follow-up period averaged 6.8 ± 2 years. Exercise capacity was reduced (p<0.0005) and the decline of peak VO2 ( 1.3 ± 3.7 %/year; p=0.015) and peak oxygen pulse ( 1.4 ± 3.0 %/year; p=0.011) was larger than normal, especially before adulthood and in female patients (p<0.01). During adulthood, RV contractility changes were significantly correlated with the decline of peak oxygen pulse (r= 0.504; p=0.047). Conclusions In patients with Senning operation for d-TGA, peak VO2 and peak oxygen pulse decrease faster with age compared to healthy controls. This decline is most obvious during childhood and adolescence, and suggests the inability to increase stroke volume to the same extent as healthy peers during growth. Peak VO2 and peak oxygen pulse remain relatively stable during early adulthood. However, when RV contractility decreases, a faster decline in peak oxygen pulse is observed.
Correction: Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry
Konstantinos Lampropoulos, Werner Budts, Alexander Van de Bruaene, Els Troost, Joost P van Melle
Cardiovascular Ultrasound , 2012, DOI: 10.1186/1476-7120-10-18
Abstract: The correct legend for Figure 1 is:Sequence analysis of systemic ventricular flow during systole and diastole in Fontan patients. The vortex from the Fontan group was consistently shorter, wider and rounder. The vortices were located at the centre of the left ventricle throughout diastole and systole and did not redirect flow in a coherent, sequential fashion as in controls. The location, shape and sphericity of the main vortices differ clearly from controls in all cardiac cycle [early diastole(A), late diastole(B), ejection (C)].The correct legend for Figure 2 is:Sequence analysis of systemic ventricular flow during systole and diastole in controls. The vortex from the control group was compact, elliptically shaped, and located apically. The location, shape and sphericity of the main vortices differ clearly from the Fontan group in all cardiac cycle [early diastole(A), late diastole(B), ejection (C)].It was also noted the legends for the Additional file 1 and Addition file 2 were also incorrect:The correct legend for Additional file 1 is:The flow patterns of a 38 year old female without cardiac abnormalitiesThe correct legend for Additional file 2 is:The flow pattern of a 29 year old male with Fontan circulation.The authors would like to apologize for any inconvenience caused by this error.
Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry
Konstantinos Lampropoulos, Werner Budts, Alexander Van de Bruaene, Els Troost, Joost P van Melle
Cardiovascular Ultrasound , 2012, DOI: 10.1186/1476-7120-10-5
Abstract: Twenty-three patients (8 Fontan and 15 normal patients) underwent echocardiography with intravenous contrast agent (Sonovue?) administration. Dedicated software was used to perform particle image velocimetry (PIV) and to visualize intracavitary flow in the systemic ventricles of the patients. Vortex parameters including vortex depth, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also measured.The data from this study show that it is feasible to perform particle velocimetry in Fontan patients. Vortex length (VL) was significantly lower (0.51 ± 0.09 vs 0.65 ± 0.12, P = 0.010) and vortex width (VW) (0.32 ± 0.06 vs 0.27 ± 0.04, p = 0.014), vortex pulsation correlation (VPC) (0.26 ± 0.25 vs -0.22 ± 0.87, p = 0.05) were significantly higher in Fontan patients. Sphericity index (SI) (1.66 ± 0.48 vs 2.42 ± 0.62, p = 0.005), relative strength (RS) (0.77 ± 0.33 vs 1.90 ± 0.47, p = 0.0001), vortex relative strength (VRS) (0.18 ± 0.13 vs 0.43 ± 0.14, p = 0.0001) were significantly lower in the Fontan patients group.PIV using contrast echocardiography is feasible in Fontan patients. Fontan patients had aberrant flow patterns as compared to normal hearts in terms of position, shape and sphericity of the main vortices. The vortex from the Fontan group was consistently shorter, wider and rounder than in controls. Whether vortex characteristics are related with clinical outcome is subject to further investigation.Particle image velocimetry is a new technique of determining the velocity and the direction of fluid streams by analyzing the change in position of small particles that drift with the fluid. With the recent development of echocardiographic technology, it is now possible to apply this approach to contrast-enhanced echocardiographic imaging [1-3].The growing knowledge about the structure and function of the ventricle [4] was of high interest to us in
Mathematical Rotordynamic Model Regarding Excitation Due to Elliptical Shaft Journals in Electrical Motors Considering the Gyroscopic Effect  [PDF]
Ulrich Werner
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.48A009

The paper presents a mathematical rotordynamic model regarding excitation due to elliptical shaft journals in sleeve bearings of electrical motors also considering the gyroscopic effect. For this kind of excitation, a mathematical rotordynamic model was developed considering the influence of the oil film stiffness and damping of the sleeve bearings, the stiffness of the end-shields and bearing housings, the stiffness of the rotor, the electromagnetic stiffness in the air gap of the electrical motor and the mass moment of inertia of the rotor and therefore also considering the gyroscopic effect. The solution of the linear differential equation system leads to the mathematical description of the absolute orbits of the shaft centre, the shaft journals and the bearing housings and to the relative orbits between the shaft journals and the bearing housings. Additionally, the bearing housing velocities can also be derived with this mathematical rotordynamic model.

Dependence of Gravity Induced Absorption Changes on the Earth’s Magnetic Field as Measured during Parabolic Flight Campaigns  [PDF]
Werner Schmidt
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.411190

Various spectroscopic experiments performed on the AIRBUS ZERO G—located in Bordeaux, France—in the years 2002 to 2012 exhibit minute optical reflection/absorption changes (GIACs) as a result of gravitational changes between 0 and 1.8 g in various biological species such as maize, oats, Arabidopsis and particularly Phycomyces sporangiophores. During a flight day, the AIRBUS ZERO G conducts 31 parabolas, each of which lasts about three minutes including a period of 22 s of weightlessness. So far, we participated in 11 parabolic flight campaigns including more than 1000 parabolas performing various kinds of experiments. During our campaigns, we observed an unexplainable variability of the measuring signals (GIACs). Using GPS-positioning systems and three dimensional magnetic field sensors, these finally were traced back to the changing earth’s magnetic field associated with the various flight directions. This is the first time that the interaction of

Gravireception in Phycomyces: Threshold Determination on the Sounding Rocket TEXUS 50  [PDF]
Werner Schmidt
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.610143
Abstract: Under parabolic flight conditions microgravity is not lower than 3 to 5 times 10-2 g. In contrast to parabolic flights, sounding rocket flights are virtually vibrational-free allowing microgravity as low as 10-5 g. Thus, a rotating platform serving as centrifuge allows the precise generation of gravitational forces ranging from 5 to 100 mg (not possible during parabolic flights). On this basis we determined the threshold1 for optical reflection/absorption changes in Phycomyces to be lower than 25 × 10-3 g. This compares well with the threshold determination of gravitropism in Phycomyces on a clinostat centrifuge. Kinetics of gravity-induced absorption changes and gravity as generated by the on-board centrifuge do not coincide but show a distinctive hysteresis with a latency of 4 s (75 mg-ramp, pull-up).
Near-Optimal Placement of Secrets in Graphs  [PDF]
Werner Poguntke
Open Journal of Discrete Mathematics (OJDM) , 2016, DOI: 10.4236/ojdm.2016.64020
Abstract: We consider the reconstruction of shared secrets in communication networks, which are modelled by graphs whose components are subject to possible failure. The reconstruction probability can be approximated using minimal cuts, if the failure probabilities of vertices and edges are close to zero. As the main contribution of this paper, node separators are used to design a heuristic for the near-optimal placement of secrets sets on the vertices of the graph.
Mathematical Multibody Model of a Soft Mounted Induction Motor Regarding Forced Vibrations Due to Dynamic Rotor Eccentricities Considering Electromagnetic Field Damping  [PDF]
Ulrich Werner
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.52032
Abstract: The paper presents a mathematical multibody model of a soft mounted induction motor with sleeve bearings regarding forced vibrations caused by dynamic rotor eccentricities considering electromagnetic field damping. The multibody model contains the mass of the stator, rotor, shaft journals and bearing housings, the electromagnetic forces with respect of electromagnetic field damping, stiffness and internal (rotating) damping of the rotor, different kinds of dynamic rotor eccentricity, stiffness and damping of the bearing housings and end shields, stiffness and damping of the oil film of the sleeve bearings and stiffness and damping of the foundation. With this multibody model, the bearing housing vibrations and the relative shaft vibrations in the sleeve bearings can be derived.
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