970 resultados para Philipp I, der Grossmütige, landgrave of Hesse, 1504-1567.


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Over the last two decades, imaging of the aorta has undergone a clinically relevant change. As part of the change non-invasive imaging techniques have replaced invasive intra-arterial digital subtraction angiography as the former imaging gold standard for aortic diseases. Computed tomography (CT) and magnetic resonance imaging (MRI) constitute the backbone of pre- and postoperative aortic imaging because they allow for imaging of the entire aorta and its branches. The first part of this review article describes the imaging principles of CT and MRI with regard to aortic disease, shows how both technologies can be applied in every day clinical practice, offering exciting perspectives. Recent CT scanner generations deliver excellent image quality with a high spatial and temporal resolution. Technical developments have resulted in CT scan performed within a few seconds for the entire aorta. Therefore, CT angiography (CTA) is the imaging technology of choice for evaluating acute aortic syndromes, for diagnosis of most aortic pathologies, preoperative planning and postoperative follow-up after endovascular aortic repair. However, radiation dose and the risk of contrast induced nephropathy are major downsides of CTA. Optimisation of scan protocols and contrast media administration can help to reduce the required radiation dose and contrast media. MR angiography (MRA) is an excellent alternative to CTA for both diagnosis of aortic pathologies and postoperative follow-up. The lack of radiation is particularly beneficial for younger patients. A potential side effect of gadolinium contrast agents is nephrogenic systemic fibrosis (NSF). In patients with high risk of NSF unenhanced MRA can be performed with both ECG- and breath-gating techniques. Additionally, MRI provides the possibility to visualise and measure both dynamic and flow information.

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Yiddish translation of: Fort comme la mort.

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Translation of: In darkest Africa.

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Mode of access: Internet.

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Pt. 6 published in Utrecht by J.A. van Woestenberg.

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Thesis (doctoral)--Friedrich-Wilhelms-Universitat zu Berlin.

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Thesis (doctoral)--Universitat Heidelberg.

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In this paper, we report the preparation and characterisation of nanometer-sized TiO2, CdO, and ZnO semiconductor particles trapped in zeolite NaY. Preparation of these particles was carried out via the traditional ion exchange method and subsequent calcination procedure. It was found that the smaller cations, i.e., Cd2+ and Zn2+ could be readily introduced into the SI′ and SII′ sites located in the sodalite cages, through ion exchange; while this is not the case for the larger Ti species, i.e., Ti monomer [TiO]2+ or dimer [Ti2O3]2+ which were predominantly dispersed on the external surface of zeolite NaY. The subsequent calcination procedure promoted these Ti species to migrate into the internal surface of the supercages. These semiconductor particles confined in NaY zeolite host exhibited a significant blue shift in the UV-VIS absorption spectra, in contrast to the respective bulk semiconductor materials, due to the quantum size effect (QSE). The particle sizes calculated from the UV-VIS optical absorption spectra using the effective mass approximation model are in good agreement with the atomic absorption data.