A DuMond-type crystal spectrometer for synchrotron-based X-ray emission studies in the energy range of 15-26 keV.

The design and performance of a high-resolution transmission-type X-ray spectrometer for use in the 15-26 keV energy range at synchrotron light sources is reported. Monte Carlo X-ray-tracing simulations were performed to optimize the performance of the transmission-type spectrometer, based on the DuMond geometry, for use at the Super X-ray absorption beamline of the Swiss Light Source at the Paul Scherrer Institute. This spectrometer provides an instrumental energy resolution of 3.5 eV for X-ray emission lines around 16 keV and 12.5 eV for emission lines at 26 keV, which is comparable to the natural linewidths of the K and L X-ray transitions in the covered energy range. First experimental data are presented and compared with results of the Monte Carlo X-ray simulations.

[Selenium administration in patients with sepsis syndrome. A prospective randomized study]. / Selensubstitution bei Sepsispatienten. Eine prospektiv randomisierte Studie.

PATIENTS AND METHOD: In this study the effect of antioxidative therapy with sodium selenite was investigated in patients with systemic inflammatory response syndrome (S. I. R. S.) and multiple organ failure. 40 patients were included in this prospective randomized study. The patients were observed over a period of 28 days. The letality rate within 28 days was excepted as main criteria. The Apache-II and the MOF-Score of Goris were used as clinical parameters. 20 patients were treated with sodium selenite over a period of 28 days. RESULT: This antioxidative therapy reduced the letality rate from 40 to 15%.

[Aluminum poisoning in dialysis patients--diagnosis and therapy]. / Aluminiumintoxikation von Dialysepatienten--Diagnostik und Therapie.

Three different dialysis procedures have been investigated and compared with respect to the efficacy of aluminium elimination in intoxicated dialysis patients. For this purpose ten patients with increased serum aluminium have been treated for two months with the chelator DFO. The effect of DFO on the aluminium clearance has been investigated. In spite of difficult conditions during studies due to an unexpected cumulation of severe adverse effects of DFO, some statements given here may be of value for the care of hemodialysis patients: 1. Both, the commonly used cuprophan filters as well as the newer highly permeable dialysis membranes like the polysulfone membrane used in our study, permit a steady but low elimination of aluminium during a dialysis session without significant difference in efficacy. A prerequisite, however, is a very low level of aluminium in the dialysate. 2. DFO induces a dose-dependent mobilization of aluminium accumulated in the tissue. The level of plasma aluminium increases distinctly, dialysable aluminium-DFO complexes are produced, and marked amounts of aluminium can thus be eliminated by the use of DFO. 3. IF DFO is used, even the economical cuprophan membrane CF1511 may lead to a satisfactory elimination rate of aluminium. Equal increase of elimination rate is achieved whether the Cuprophan membrane CF1511 is combined with the hemoperfusion filter Alukart or the highly permeable polysulfone membrane F60 is used alone. This is of importance particularly in cases of severe intoxication with aluminium. The polysulfon dialysator may be preferred to conventional membranes combined with hemoperfusion because of the simpler handling. 4. In order to prevent accumulation of aluminium in dialysis patients, besides the use of dialysates poor in aluminium, phosphate binders containing aluminium should be avoided completely if possible. They may be replaced by the two phosphate binders calcium carbonate and calcium acetate and a diet poor in phosphates. The use of aluminium-containing phosphate-binders should be restricted to exceptional cases such as patients with hypercalcemia, severe intolerance of calcium-containing phosphate-binders or patients with hyperphosphatemia that cannot be treated otherwise. 5. Finally, regular controls of plasma aluminium levels are mandatory in dialysed patients. In cases with an increase over 50 micrograms/l and positive DFO test, DFO treatment should be initiated. Low doses of 10 mg/kg body weight DFO per week are actually in use for those cases.(ABSTRACT TRUNCATED AT 400 WORDS)

[Uncertainties in the localization of radiation sources in brachytherapy]. / Unsicherheiten bei der Strahlenquellenlokalisation in der Brachytherapie.

While investigating ways to solve the problem of locating radiation sources applied in brachytherapy a device was constructed which enables a precise assessment of their or their applicators' position from two only roughly positioned orthogonal radiographs. The overall accuracy (including exposure and evaluation) achieved is +/- 1 mm. The constructional elements and the evaluation algorithm are described and the influence of the location uncertainty on the uncertainty of the dose applied are discussed.