Plasmafysica - een nieuwe positiebepaling

Reviews recent developments in plasma physics, with special reference to the prospect of fusion of light atomic nuclei. A table summarises properties of low-temperature plasmas. The Joint European Torus, MHD generators, INTOR and special applications in atomic physics and astrophysics are discusse

Damping and dispersion of linear longitudinal oscillations in a multi-component plasma. II

Linear dispersion phenomena in Vlasov-Poisson plasma's with drift are studied in order to be able to test the relevance of linear theory for plasma turbulence. Especially the effect of the addition of light ions, giving rise to stabilisation, is taken into account. Emphasis is laid on approximate methods that give the possibility to investigate the influence of parameters like ion-mass-ratio, temperature ratio etc. Numerical results are given for a He-A plasma.</p

Prognostic biomarker soluble ST2 exhibits diurnal variation in chronic heart failure patients

Aim: Soluble suppression of tumorigenicity-2 (sST2) is a strong prognostic biomarker in heart failure. The emerging understanding of circadian biology in cardiovascular disease may lead to novel applications in prognosis and diagnosis and may provide insight into mechanistic aspects of the disease–biomarker interaction. So far, it is unknown whether sST2 exhibits a diurnal rhythm. Repeated measurements of sST2 may aid in clinical decision making. The goal of this study was to investigate whether sST2 exhibits diurnal variation in patients with heart failure with reduced ejection fraction (HFrEF) and in control subjects, thereby enhancing its diagnostic and prognostic values. Methods and results: The study comprised 32 subjects: 16 HFrEF patients and 16 controls. Blood was collected at seven subsequent time points during a 24 h time period. sST2, N-terminal pro-B-type natriuretic peptide (NT-proBNP), melatonin, and cortisol were measured from serum. Peak values of sST2 clustered at daytime (modal value: 5 p.m.) in 87.6% of all subjects (81.3% of patients, P = 0.021; 93.8% of controls, P = 0.001), and minimum concentrations at night-time (modal value: 5 a.m.) in 84.4% (87.5% of patients, P = 0.004 81.3% of controls, P = 0.021). A cosinor analysis of mean normalized sST2 values revealed significant cosine shaped 24 h oscillations of patients (P = 0.026) and controls (P = 0.037). NT-proBNP in contrast did not show a diurnal rhythm, while melatonin and cortisol patterns were intact in all subjects. Conclusions: sST2 exhibits a diurnal rhythm with lower values in the morning than in the late afternoon. This new insight could lead to refinement of its diagnostic and prognostic values through specified and consistent sampling times with repeated measurements. For example, by measuring sST2 during the afternoon, when levels are at their highest, false negatives on prognosis prediction could be avoided

Enquete arbeidsmarkt voor fysici 2002

Resultaten van een onderzoek naar de arbeidsmarkt en de aansluiting tussen werk en opleiding voor natuurkundigen afgestudeerd tussen 1990 en 2000. Dit is het derdel deel uit een reeks onderzoeken naar de Arbeidsmarkt voor Fysici.Resultaten van een onderzoek naar de arbeidsmarkt en de aansluiting tussen werk en opleiding voor natuurkundigen afgestudeerd tussen 1990 en 2000. Dit is het derde deel uit een reeks onderzoeken naar de Arbeidsmarkt voor Fysici