Cesium and iodine, which are formed during a fission process in a nuclear reactor, are considered as major fission products responsible for the environmental burden in case of a nuclear accident. ...From the safety point of view, it is thus important to understand their release mechanism when overheating of the reactor core occurs. This work presents an experimental investigation of the behaviour of caesium iodide and caesium fluoride in fluoride based molten salt reactor fuel during high temperature events. It has been demonstrated that CsF will be retained in the fuel salt and thus its volatility will be significantly reduced, while CsI will not dissolve in the fluoride-based fuel matrix and will thus remain more volatile. The influence of the presence of CsI and CsF on the melting behaviour of the fuel has been investigated using calorimetry, revealing their negligible effects.
CsF dissolves in fluoride based MSR fuel, which significantly decreases its volatility. CsI has very low solubility in the fuel. Exchange between iodides and fluorides occurs in the MSR fuel, stabilizing the Cs cations in the fuel mixture.
The combination of chemotherapy with the vascular endothelial growth factor (VEGF) antibody bevacizumab is a standard of care in advanced colorectal cancer (CRC). However, biomarkers predicting ...outcome of bevacizumab-containing treatment are lacking. As angiopoietin-2 (Ang-2) is a key regulator of vascular remodelling in concert with VEGF, we investigated its role as a biomarker in metastatic CRC.
Serum Ang-2 levels were measured in 33 healthy volunteers and 90 patients with CRC. Of these, 34 had metastatic disease and received bevacizumab-containing therapy. To determine the tissue of origin of Ang-2, quantitative real-time PCR was performed on microdissected cryosections of human CRC and in a murine xenograft model of CRC using species-specific amplification.
Ang-2 originated from the stromal compartment of CRC tissues. Serum Ang-2 levels were significantly elevated in patients with metastatic CRC compared with healthy controls. Amongst patients receiving bevacizumab-containing treatment, low pre-therapeutic serum Ang-2 levels were associated with a significant better response rate (82 vs 31%; P<0.01), a prolonged median progression-free survival (14.1 vs 8.5 months; P<0.01) and a reduction of 91% in the hazard of death (P<0.05).
Serum Ang-2 is a candidate biomarker for outcome of patients with metastatic CRC treated with bevacizumab-containing therapy, and it should be further validated to customise combined chemotherapeutic and anti-angiogenic treatment.
For measurements of the neutron-induced fission cross section of 242Pu, large-area (42cm2) 242Pu targets were prepared on Ti-coated Si wafers by means of constant current density molecular plating. ...Radiochemical separations were performed prior to the platings. Quantitative deposition yields (>95%) were determined for all targets by means of alpha-particle spectroscopy. Layer densities in the range of 100–150μg/cm2 were obtained. The homogeneity of the targets was studied by radiographic imaging.
A comparative study between the quality of the layers produced on the Ti-coated Si wafers and the quality of layers grown on normal Ti foils was carried out by applying scanning electron microscopy and energy dispersive X-ray spectroscopy. Ti-coated Si wafers resulted clearly superior to Ti foils in the production of homogeneous 242Pu layers with minimum defectivity.
•Large area (i.e., 42cm2) 242Pu targets were prepared on Ti-coated Si wafers.•Quantitative deposition yields (>95%) were obtained.•Homogeneous 242Pu layers with minimum defectivity were produced.•The targets were prepared for future 242Pu(n, f) cross section measurements.
To improve the properties and performance of thin layers produced by molecular plating as targets for nuclear experiments investigations with lanthanide elements (i.e., natural Nd and
147
Sm-enriched ...Sm) were carried out. Plating parameters like roughness of the deposition substrate, plating solvent, electrolyte concentration, and applied current density were varied. The influence of each parameter on the properties of the layers was studied by characterizing the deposits. The characterizations showed that nuclear targets perform differently depending on their layer properties. The results obtained from the investigations were applied for the quantitative preparation of homogeneous large-area (i.e., 42 cm
2
)
242
Pu targets to be used for transmutation-relevant experiments.
The ternary oxide ceramic system UO2-ZrO2-FeO is a refractory system that is of great relevance to the nuclear industry as it represents one of the main systems resulting from the interaction of the ...Zircaloy cladding, the UO2 fuel and the structural elements of a nuclear reactor. It is particularly the high temperature properties that require investigation; that is, when substantial overheating of the nuclear core occurs and interactions can lead to its degradation, melting and result in a severe nuclear accident. There has been much work on the UO2-ZrO2 system and also on the ternary system with FeO but there is still a need to examine 2 further aspects; firstly the effect of sub-oxidized systems, the UO2-Zr and FeO-Zr systems, and secondly the effect of Fe/Zr or Fe/U ratios on the melting point of the U-Zr-Fe oxide system. Samples of UO2-Zr and UO2-ZrO2-FeO were fabricated at ITU and then characterized by optical microscopy (OM) and X-ray diffraction to determine the ceramic's structure and verify the composition. Thereafter the samples are to be melted by laser flash heating and their liquidus and solidus temperatures determined by pyrometry. This programme is currently ongoing. The frozen samples, after testing, were then sectioned, polished and the molten zone micro-analytically examined by OM & SEM-EDS in order to determine its structure and composition and to compare with the existing phase diagrams. Examples of results from these systems will be given. Finally, a reacted Zr-FeO thermite mixture was examined, which had been used to generate high temperatures during tests of reactor melt-concrete interactions. The aim was to assess the reaction and estimate the heat generation from this novel technique. These results allow verification or improvement of the phase diagram and are of primary importance as input to models used to predict materials interactions in a severe nuclear accident.
Mittels Farbdoppler zeigt sich das kombinierte Trikuspidalklappenvitium mit hochgradiger Insuffizienz und hochgradiger Stenose. c Quantifizierung der Stenose mittels CW(„continuous wave“)-Doppler ...(dPmean 5 mm Hg) Positronenemissionstomographie (PET) mit 98 MBq Ga-68-DotaTATE mit Low-dose-Computertomographie (CT). Davar, J; Connolly, HM; Caplin, ME; Pavel, M; Zacks, J; Bhattacharyya, S; Cuthbertson, DJ; Dobson, R; Grozinsky-Glasberg, S; Steeds, RP; Dreyfus, G; Pellikka, PA; Toumpanakis, C. Diagnosing and managing carcinoid heart disease in patients with neuroendocrine tumors: an expert statement. Carcinoid heart disease: diagnosis and management. Carcinoid heart disease: current understanding and future directions. Surgery of carcinoid heart disease: current outcomes, concerns and controversies.
For measurements of the neutron-induced fission cross section of super(242)Pu, large-area (42 cm super(2)) super(242)Pu targets were prepared on Ti-coated Si wafers by means of constant current ...density molecular plating. Radiochemical separations were performed prior to the platings. Quantitative deposition yields (>95%) were determined for all targets by means of alpha-particle spectroscopy. Layer densities in the range of 100-150 mu g/cm super(2) were obtained. The homogeneity of the targets was studied by radiographic imaging. A comparative study between the quality of the layers produced on the Ti-coated Si wafers and the quality of layers grown on normal Ti foils was carried out by applying scanning electron microscopy and energy dispersive X-ray spectroscopy. Ti-coated Si wafers resulted clearly superior to Ti foils in the production of homogeneous super(242)Pu layers with minimum defectivity.
Neuroendokrine Tumoren Schmidt, M; Cremer, B; Drzezga, A
Best practice onkologie,
03/2014, Letnik:
9, Številka:
1
Journal Article
Recenzirano
ZusammefassungFür neuroendokrine Neoplasien (NEN) stehen aufgrund ihrer Expression von Somatostatinrezeptoren für die Diagnostik SPECT- oder PET-Radiopharmaka (Ga-68-markierte Peptide) zur Verfügung. ...Für die Therapie kommen Lu-177- oder Y-90-markierte Peptide zum Einsatz. Die Peptidrezeptor-Radionuklidtherapie (PRRT) kommt typischerweise bei G1/G2-NEN (Ki-67 < 20 %) im metastasierten und damit inoperablen Stadium nach oder alternierend zu Sandostatin zum Einsatz. Während es für pankreatische NEN chemotherapeutische Therapieoptionen vor einer PRRT gibt, kommt bei extrapankreatischen NEN bevorzugt eine PRRT zur Anwendung. Eine PRRT ist meist nebenwirkungsarm, insbesondere bei Verwendung Lu-177-markierter Peptide. Allerdings sind hämatotoxische und nephrotoxische Nebenwirkungen möglich. Karzinoidkrisen oder myelodysplastische Syndrome sind selten (< 1–2 %). Meist sind mit einer PRRT partielle Remissionen (ca. 40 %) oder eine Krankheitsstabilisierung (ca. 35 %) mit medianen Überlebenszeiten von 46–59 Monaten zu erreichen. Bei prognosebestimmender Lebermetastasierung steht eine selektive interne Radionuklidtherapie (SIRT) mit Y-90-markierten Mikrosphären zur Verfügung.
Neuroendokrine Tumoren Schmidt, M.; Cremer, B.; Drzezga, A.
Best practice onkologie,
2014/3, Letnik:
9, Številka:
1
Journal Article
Recenzirano
Zusammefassung
Für neuroendokrine Neoplasien (NEN) stehen aufgrund ihrer Expression von Somatostatinrezeptoren für die Diagnostik SPECT- oder PET-Radiopharmaka (Ga-68-markierte Peptide) zur ...Verfügung. Für die Therapie kommen Lu-177- oder Y-90-markierte Peptide zum Einsatz. Die Peptidrezeptor-Radionuklidtherapie (PRRT) kommt typischerweise bei G1/G2-NEN (Ki-67 < 20 %) im metastasierten und damit inoperablen Stadium nach oder alternierend zu Sandostatin zum Einsatz. Während es für pankreatische NEN chemotherapeutische Therapieoptionen vor einer PRRT gibt, kommt bei extrapankreatischen NEN bevorzugt eine PRRT zur Anwendung. Eine PRRT ist meist nebenwirkungsarm, insbesondere bei Verwendung Lu-177-markierter Peptide. Allerdings sind hämatotoxische und nephrotoxische Nebenwirkungen möglich. Karzinoidkrisen oder myelodysplastische Syndrome sind selten (< 1–2 %). Meist sind mit einer PRRT partielle Remissionen (ca. 40 %) oder eine Krankheitsstabilisierung (ca. 35 %) mit medianen Überlebenszeiten von 46–59 Monaten zu erreichen. Bei prognosebestimmender Lebermetastasierung steht eine selektive interne Radionuklidtherapie (SIRT) mit Y-90-markierten Mikrosphären zur Verfügung.
PDF
