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The health impact of iron (Fe) deficiency or excess on the human body can be severe. Existing clinical methods for assessing body Fe levels have limitations. This thesis focuses on the potential of measuring skin Fe concentrations using X-ray Fluorescence (XRF) to assess body Fe levels. A portable XRF instrument based on a silicon drift detector has been developed. The instrument was calibrated using water-based phantoms, achieving a minimum detection limit of 1.35 ± 0.35 ppm (Fe) with a measurement time of 1800 s and a radiation dose of 1.1 ± 0.1 mSv to the skin surface. The system accuracy was tested by measuring the skin Fe concentrations in 10 pig skin samples that were not loaded with Fe. The measured pig skin Fe ranged from approximately 8 to 14 ppm with an average value of 11 ppm. The XRF measurements were found to compare well with the results from Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) analysis of the same skin samples. The mean difference between the Fe levels as assessed by XRF and ICP-MS was not significant, measuring at 2.5 ± 4.6 ppm. Synchrotron µXRF mapping of 25 μm thick pig skin sections at a spatial resolution of 20 µm revealed Fe ‘hot spots’ through the skin, predominantly in the dermis, that were attributed to small blood vessels. The synchrotron map also showed that the Fe distribution in the skin peaks near the outer skin surface. Measurements by the system of this skin distribution were modelled using the Monte Carlo code EGS5 and indicated that if a highly elevated Fe layer is present at the surface, correction factors may be necessary for accurate estimation of skin surface Fe levels by the XRF system. The performance of the system was tested using rat skin samples obtained from animals dosed in vivo with varying amounts of Fe. The system was able to distinguish between skin samples from normal rats and rats dosed with 80 mg Fe2+ and between rats dosed with 80 mg Fe2+ and 160 mg Fe2+ (p = 0.001 and p=0.002, respectively). The instrument also exhibited a significant linear relationship between the measured rat skin Fe concentration and rat Fe dose (R2 = 0.84, p < 0.0001). Furthermore, the measurements were validated against a laboratory XRF system, a bulk tissue measurement system (R2 = 0.85, p < 0.0001). Overall, the work in this thesis highlights the promise of using portable XRF for precise and non-intrusive measurement of skin Fe levels in both Fe overload and Fe deficiency conditions. / Thesis / Doctor of Philosophy (PhD)

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Denisa Mazouchová Supervizor: Mgr. Monika Kuchařová, Ph.D. Title of diploma thesis: Effect of ultraviolet radiation on the change the mechanical parameters of human skin This diploma thesis deals in theoretical part with the properties of human skin, the characteristics of the UV radiation and its effects on human skin. The practical part of the thesis focuses on the in vivo measurement of mechanical parameters of human skin after UV radiation. Mechanical characteristics of human skin were measured in 12 subjects before the application of UV radiation, immediately after application of UV and after 24 hours of rest skin. The experiment used a UV lamp with a wavelength of 370 nm emitted light. The monitored parameters were Hooke's and Newton's coefficients. Hooke's coefficient gives us the stiffness of the skin as a whole , Newton coefficient characterises its viscosity. For measurement of those parameters was used dynamic viscoelastomer. The experiment has been found out that no signifiant ganges of Hooke's and Newton's coefficients were not found immediately after the application of UV radiation of wavelength 370 nm, in 12 volunteers. Significant change occurred only in the...

Cette thèse traite de la manière dont le musicien contrôle les régimes d'oscillation d'un instrument de la famille des cuivres. L'’association d’'un instrument et d'un musicien forme un système dynamique complexe. Le couplage non linéaire entre les lèvres et la colonne d’'air peut mener à un régime stationnaire, des auto-oscillations périodiques ou quasi-périodiques. De nombreux paramètres de contrôle permettent à un musicien de choisir le régime d’oscillation.Deux approches sont utilisées pour comprendre l’'émergence des régimes de l’'instrument et leur contrôle par le musicien. D'’une part, on étudie un modèle physique de cuivre, consistant en une valve à 1 degré de liberté couplée non linéairement à une expression modale de l’'impédance d’'entrée de l’'instrument. Les caractéristiques des régimes de ce modèle sont étudiés par analyse de stabilité linéaire, simulation numérique et équilibrage harmonique. L’'objectif est d'’estimer la capacité de ce modèle à reproduire le comportement de l’'instrument. Un outil expérimental est également développé pour mesurer simultanément des paramètres de contrôle employés par les musiciens et des variables de jeu.Les résultats améliorent la compréhension des régimes d’oscillation des cuivres. Les mesures expérimentales donnent les plages de variation des paramètres de jeu. Les résultats des méthodes d'’analyse se complètent, donnant une vision globale de l’'apparition des régimes oscillants du modèle et des informations détaillées sur certains points de fonctionnement. Certaines situations de jeu particulières sont étudiées: note pédale du trombone, ’influence de l’'utilisation d’'une sourdine et nature des sons multiphoniques. / This thesis focuses on how a musician controls and chooses the oscillation regimes of brass instruments.The association of an instrument and a musician is a complex dynamical system. The nonlinear coupling between the lips and the resonator can lead to a stationary regime, periodic or quasi-periodic self-sustained oscillations. Through several control parameters, a musician can select the desired regime.Two approaches are developed to understand the emergence of the instrument oscillation regimes and how a musician controls it. A physical model of brass instrument is studied. It consists in a one-degree-of-freedom lip valve nonlinearly coupled to a modal fit of the input impedance of the instrument. The features of several oscillation regimes of this model are studied through linear stability analysis, numerical simulation and harmonic balance. Goals are the assessment of the ability of this model to reproduce the behavior of the modelled instrument. An experimental setup is also developed to measure simultaneously playing parameters used by a musician and instrument variables.Results provide a better understanding of the behavior of brass instrument oscillation regimes. Measurements provide ranges of the control parameters. Results of the analysis methods of the model are complementary. A global vision of the occurrence of certain oscillation regimes is provided, along with more detailed information for some operating points. Some specific playing situations are examined in detail, such as the trombone pedal note, the influence of a passive or active mute on the latter, and the nature of multiphonic sounds.